article ludovia (de 22 000 à 30000 caractères espaces compris) academic journal of science, engineering and technology vol.1, issue 1; march -2023; https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 24| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset advancements in dressing techniques for metal-bonded diamond grinding wheels yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang harbin university of science and technology, harbin, 150080, china abstract metal-bonded diamond grinding wheels are widely used for precision and ultra-precision grinding of hard and brittle materials due to their high grinding efficiency, low processing cost, and other characteristics. however, the poor self-sharpness and easy blockage of metal-bonded diamond grinding wheels can affect the stability of the grinding process and the grinding surface quality. additionally, the shape accuracy of the grinding wheel can be destroyed during the grinding process of hard and brittle materials, which can also affect the grinding surface accuracy and surface quality. to address these issues, a swing arm type electric spark dressing device has been designed to realize high dressing precision. this paper presents an electric sparking experiment using the dressing device. the experimental results show that higher dressing efficiency and low arc precision can be obtained with large electrical parameters, while higher arc precision and lower efficiency could be obtained with small electrical parameters. the experiment can guide the selection of different parameter combinations in different dressing stages to improve the dressing efficiency and precision. in summary, this paper proposes a new dressing technique for metal-bonded diamond grinding wheels, which can improve dressing efficiency and precision, and thus contribute to high-efficiency and high-quality finishing technology for hard and brittle materials. this technique has the advantages of low cost, easy realization, and easy adjustment, making it a promising choice for dressing metal-bonded diamond grinding wheels. keywords: metal-bonded diamond grinding wheel, dressing technique, electric spark, swing arm, dressing precision, grinding surface accuracy introduction the metal-bonded diamond grinding wheel has the characteristics of strong grinding ability, low grinding force, low grinding temperature, high grinding efficiency, small grinding loss, high holding strength to abrasive grains and low processing cost [1]. it is widely used in precision and ultra-precision grinding of hard and brittle materials. however, the metal-bonded diamond grinding wheel has poor self-sharpness and is easy to block. the exciting force caused by the eccentricity of the grinding wheel is easily generated, which affects the stability of the grinding process and the grinding surface quality. the shape of the grinding wheel is severely worn during the grinding process of the hard and brittle material, such as the silicon carbide ceramics, which seriously affects the precision of the workpiece. therefore, the high-efficiency and high-quality finishing technology of the metal bond diamond grinding wheel becomes the key technology for achieving hard and brittle material grinding.[2] electric spark shaping can realize in-situ shaping and sharpening and easy to ensure grinding precision; be easy to operate and suitable for any grinding wheel with conductive material as bonding agent; generate low grinding force and suitable for the dressing process of grinding wheels with small diameter and very thin mailto:topacademicjournals@gmail.com yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang advancements in dressing techniques for metal-bonded diamond grinding wheels 25| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset thickness. the method has the advantages of low cost, easy realization, less process parameters, easy adjustment and the like, which is the best choice for dressing of metal-bonded diamond grinding wheel. [3] eun-sang lee et al.[4] used the on-line electric spark sharpening technology in precise grinding of the mn-zn ferrite material, and the obtained results reveal that surface roughness was reduced and the surface was free of cracks, the grinding force was also reduced. j. tamaki and k. kondoh[5] proposed in-process electrodischarge dressing (iedd) to achieve dressing of the grinding wheel and good dressing quality was gained. xie jinet al.[6] conducted an experimental study on electro-contact discharge dressing (ecdd). the experimental results show that the factors affecting the morphology and protrusion height of the diamond abrasives are the discharge pulse current amplitude and pulse width. this dressing method is suitable for dressing after passivation of the coarse-grained grinding wheel. brian k. rhoney et al.[7] proposed the wire electrical discharge machining technique (fig.1), which uses the energy generated by the discharge between the electrode wire and the metal-based diamond wheel to remove the metal bond. hu dejin, wang yan et al.[8] proposed a gas-assisted discharge-assisted dressing technique that combines mechanical dressing of diamond pens with spark-discharge dressing in gas. the surface quality of the grinding wheel after the method is improved, and the wear of the diamond pen is reduced. fig.1 wire electrical discharge machining technique[7] cai lanronget al.[9] proposed a mist discharge repairing technology, which reduces the dependence on liquid media and conforms to the trend of green manufacturing. this technology can be applied to online trimming. suzhou electric machine tool research institute[10] developed a edm forming machine that can be used to dressing diamond wheels with a maximum thickness of 100mm and a diameter range of 100~400mm. the finished diamond wheel has high forming precision and high durability. in this paper, an in-position electric spark dressing device was designed for the arc-shaped metal-bonded diamond grinding wheel used in large-scale sic ceramic aspherical grinding. the relevant process experiments are completed, which provides certain technical guidance for the in-position dressing of the metal-bonded diamond grinding wheel. 1. structure design of the dressing device the forming arc of the grinding wheel is the working part. the arc profile wear is serious in grinding process of hard and brittle materials such as silicon carbide ceramics, which affects the performance of the grinding wheel. therefore, it is necessary to ensure the arc of the arc profile after the dressing process. as the radius of the arc of the diamond grinding wheel is small, the trajectory formed by dressing electrode is an arc with the same radius of the grinding wheel arc, so as to achieve the purpose of dressing the grinding wheel arc. in the dressing process, the loss of the dressing electrode can be compensated to improve the accuracy of the arc contour. therefore, it is necessary to consider the realization of the swing mode and the compensation of the dressing electrode loss in designing process. fig.2 shows a schematic diagram of edm device. the device is mainly composed of a stepping motor, a swinging rod, a v-shaped block and an electrode. electrode diamond pen feeding motion feeding motion metal-bonded grinding wheel yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang advancements in dressing techniques for metal-bonded diamond grinding wheels 26| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 2 structure of the electric spark dressing device during the dressing process, both the electrode and the grinding wheel are consumed, and the discharge gap needs to be compensated at this time. the electrode consumption is extremely small during the trimming process, so the electrode tip position can be fixed to the standard position before each dressing process. therefore, it is necessary to set a positioning reference on the dresser, such as the v-shaped block shown in fig.3. when positioning, a positioning shaft with a diameter of 8 mm is mounted on the v-shaped block, and the height of the shaping electrode is adjusted so that the top end of the shaping electrode is in contact with the positioning shaft. the grinding wheel compensation behavior is achieved by the downward feed motion of the grinding wheel. the point in time and distance of the compensation motion can be determined by observing the current value on the dressing power supply. figure. 3 diagram of electrode positioning the electric spark shaping device fully utilizes the feeding function of the grinding head of the grinding machine which simplifies the structure, and improves the dressing precision. therefore, it is used as the final shaping solution. fig.4 shows the physical picture of the device. figure. 4 physical picture of the electric spark dressing device stepper motor swing rod trimming electrode insulating sleeve grinding wheel v block swing rod v block trimming electrode positioning axis press plate yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang advancements in dressing techniques for metal-bonded diamond grinding wheels 27| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. experiments and results 2.1 establishment of experimental system in order to study the dressing precision, the in-position dressing experiments of metal-bonded diamond grinding wheel were designed. the electric spark dressing system includes a dc pulse power supply, the electric spark dressing device, grinding wheel and dressing coolant. figure 4-1 shows the physical picture of the edm experiment system. the grinding wheel is mounted on the spindle, while the shaping device is mounted on the table of the grinding machine. the dc pulse power supply provides pulse current for spark dressing. positive polarity dressing is adopted, the positive electrode of the dc pulse power supply is connected to the grinding wheel, and the negative electrode is connected to the electrode. the coolant is added to the gap by a wet brush and a surface of the grinding wheel. 2.2 experimental condition in the process of edm, the efficiency and the shape accuracy are quite different with different electrical parameters. in order to study the influence of different electrical parameter combinations on the dressing accuracy, two group of experimental parameters considering voltage, duty cycle and pulse period were set to compare the obtained circularity of the grinding wheel. the specific parameters are shown in table 4-2. table 1 list of experimental parameters test number voltage(v) duty cycle pulse period(μs) dressing rate(rpm) 1 90 50% 60 3 2 60 50% 40 3 the roundness of the dressed grinding wheel cannot be directly measured. therefore, the cutting grinding experiment is performed using the dressed grinding wheel, and the circular arc of the grinding wheel is indirectly reflected by detecting the circular arc groove. the arc was measured using a talysurf pgi plus profiler. 2.3 experimental results the dressed arc of grinding wheel is obtained by the profilometer, fig.5 shows the results of the circular arc obtained by the test number 1. from the test results, it can be seen that the overall shape of the arc is not ideal, and there is a big gap with the ideal arc. the bottom of the circular arc has obvious defects, comparing with the ideal circular arc. the bottom of the circular arc has obvious convexity, which is reveal that there exit a pit on the surface of the grinding wheel. the left and right parts of the arc groove have significant fluctuations. it can be seen that the largest arc error is 6 μm at the bottom. yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang advancements in dressing techniques for metal-bonded diamond grinding wheels 28| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 5 experimental result with test no.1 82 fig.6 shows the results of the circular arc obtained by the test number 2. it can be seen from the inspection chart that the profile of the arc is greatly improved compared with the previous one. there still defects at the bottom of the arc, but the profile on both sides of the arc groove is ideal. although the error at the bottom of the arc is up to 7.5 μm, the error of the arc surface on both sides is mostly within 2 μm. figure. 6 experimental result with test no.2 from the comparison of the above two experiments, it can be concluded that when a large electrical parameter is selected, the electrode and the grinding wheel are not sensitive to the discharge gap, and it is difficult to ensure high dressing accuracy. when a smaller electrical parameter is used, the electrode and the grinding wheel are more sensitive to the discharge gap, and a higher dressing accuracy can be ensured. therefore, when performing spark dressing, large electrical parameters can be used first to obtain higher dressing efficiency. and small electrical parameters should be used to obtain higher dressing precision. yaxin wang, xiang li, yunlei song, lifei liu, liwei sun & shizong zhang advancements in dressing techniques for metal-bonded diamond grinding wheels 29| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. conclusion for metal-bonded diamond grinding wheel, an electric spark dressing device was developed. the effects of different shaping parameters (pulse voltage, duty cycle and period) on dressing accuracy of were studied by in-position spark dressing experiments. the following conclusions were drawn: 1. edm technology can achieve high-quality and high-quality in dressing of metal-bonded diamond grinding wheel; 2. high dressing efficiency can be achieved with larger electrical parameters while high dressing accuracy can be gained with smaller electrical parameters. references [1]. w.c. ye. (2002). reasonable use of superhard-abrasive grinding wheel. products & technology, no.5, p.47-50. [2]. g.q. cai, b.f. feng. (2003). latest advances in grinding and abrasivemachining. aeronautical manufacturing technology, no.4, p.31-35. [3]. kim j d, lee y j. (1994). mirror surface grinding for brittle materials with inprocess electrolytic dressing. journal of materials engineering and performance, vol.3, no.1, p.159-167. [4]. lee e s, ahn s o.(1999). precision surface grinding of mn–zn ferrite with inprocess electro-discharge dressing (iedd). international journal of machine tools and manufacture, vol.39, no.10, p.1655-1671. [5]. tamaki j, kondoh k, iyamat.(1999). electro-contact discharge dressing of metal-bonded diamond grinding wheel utilizing a hybrid electrode. journal of japan society for precision engineering, vol.35, no.11, p.1628-1632. [6]. xie j, tamaki j. (2006). in-process evaluation of grit protrusion feature for fine diamond grinding wheel by means of electro-contact discharge dressing. journal of materials processing technology, vol.180, no.1, p.83-90. [7]. rhoney b k, shih a j, scattergood r o, et al. (2002). wire electrical discharge machining of metal bond diamond wheels for ceramic grinding. international journal of machine tools and manufacture, vol 42, no.12, p.1355-1362. [8]. y. wang, x.j. zhou, d.j. hu.(2006). experimental study on dry electrical discharge assisted truing and dressing of diamond wheel. journal of materials processing technology, vol.42, no.7, p.222-226. [9]. l.r. cai, y. jia. (2009). dressing of metal-bonded superabrasive grinding wheels by means of mist-jetting electrical discharge technology. international journal of machine tools and manufacture, vol 202, no.2, p.779-784. [10]. m.x. ma.(1999). study on accuracy of edm of metal bonded diamond micro-powder wheel. diamond abrasives engineering, vol.111, no.3, p.20-23. academic journal of science, engineering and technology vol.1, issue 1; march -2023; https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 1| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset exploring the potential of ice and snow leisure sports tourism in china huang qi physical education and research department, heilongjiang bayi agricultural university, daqing 163319, china abstract: the integration of ice and snow sports and tourism industry has a promising future in the internet era, providing a greater platform for the development of the industry. china is endowed with abundant ice and snow resources, yet the training of professional talents and the construction of facilities need to be further improved to promote the growth of the ice and snow sports tourism industry. in this context, the application of multimedia technology can play a vital role in promoting the development of ice and snow leisure sports in china. by establishing a nationwide model of ice and snow sports tourism industry, we can further strengthen the integration of ice and snow leisure sports and tourism industry and promote the industry's sustainable development. this paper explores the potential of ice and snow leisure sports tourism in china and proposes a comprehensive strategy to enhance the industry's development. the research is based on an extensive review of the literature and data analysis of the current status of the industry. the findings indicate that the integration of ice and snow sports and tourism industry has a significant potential in china, yet there are challenges that need to be addressed, such as the shortage of professional talents and facilities. to overcome these challenges, the paper proposes a framework for the development of ice and snow sports tourism industry, which includes the establishment of professional talent training programs, the improvement of infrastructure, and the application of multimedia technology to enhance the tourist experience. the paper concludes that the implementation of the proposed strategy can effectively promote the development of ice and snow leisure sports. keywords: ice and snow sports, tourism industry, multimedia technology, professional talent, facilities, leisure sports, integration, china. introduction in recent years, the state and relevant management departments have paid attention to the formulation of rules and regulations related to ice and snow sports, and the promulgation of relevant documents has provided a broader development platform for the development of ice and snow leisure sports in china. china's ice and snow sports take sports and leisure activities as the main focus, so the development of ice and snow leisure sports should also meet the needs of the development of national ice and snow sports. on the basis of the wide range of ice and snow sports, people's demand for ice and snow leisure is also gradually increasing. ice and snow leisure sports tourism activities are based on rich ice and snow resources, deeper cultural heritage and more diversified ice and snow sports activities. with the support of multimedia technology and the integration of sports and tourism industry, china's ice and snow leisure sports can be better developed, providing greater development space for the development of china's ice and snow sports tourism [1]. development of ice and snow sports tourism in china ice and snow sports tourism first appeared in europe, and developed and expanded in european and american countries. based on rich ice and snow resources, it attracts more ice and snow sports fans to actively participate in ice and snow sports and leisure projects, and ultimately achieve the goal of physical fitness and happy mood. ice and snow sports tourism is to develop ice and snow sports projects according to the existing ice and snow resources, guide tourists to participate in them, so that athletes can release their emotions. ice and snow mailto:topacademicjournals@gmail.com huang qi exploring the potential of ice and snow leisure sports tourism in china 2| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sports tourists are connected with ice and snow resources tourism sites and society in the process of participating in ice and snow sports exercises and competitions. since china has won the chance to host the 2022 winter olympic games, the enthusiasm of the ice and snow sports tourism market has risen unprecedentedly, which has made the construction and layout of ice and snow sports tourism constantly improved. under this background, the relevant national departments have issued relevant measures to ensure the gradual improvement of the ice and snow sports industry as far as possible, fully create a better external development environment for the development of ice and snow sports tourism, and enable the government to play its guiding role. after being valued by all aspects of society, ice and snow sports also attract more forces to participate in the ice and snow sports industry. china attaches great importance to the development of the ice and snow sports industry. ice and snow sports tourism is an important component of the ice and snow sports industry and a major way to attract people to participate in ice and snow sports. it is necessary to provide a better development environment for the development of ice and snow sports tourism. ice and snow field resources are an important basis for the development of ice and snow sports tourism. on the basis of the accelerated development process of ice and snow sports, the number of ice and snow fields in china has also been increased. the strength of all aspects of society has improved the quantity and quality of ice and snow fields. with the specific presentation of the economic benefits of ice and snow sports tourism, ice and snow sports tourism has also expanded to more areas. the number of provinces and cities implementing ice and snow sports tourism activities in china has increased, and gradually become a new economic industry. the ice and snow sports tourism industry can help optimize the development of china's economic structure, and the national and social capital theory has also increased the construction of ice and snow venues and resources. with the development of information technology in china, multimedia technology has been widely used in many fields, and the popularity of multimedia technology in china has also been generally improved. in the process of social development, the emergence of multimedia technology has also led to new forms of life in society. combined with the data information of china's internet information center, the size of internet users in china has reached six hundred million, the internet penetration rate is high, and the equipment of internet users in china is more diversified. mobile internet has also become an important reason for the increase in the number of internet users. the good development trend of multimedia technology makes ice and snow sports tourism face more development opportunities. the ice and snow sports tourism industry will also be able to build a better ice and snow sports tourism mobile platform based on multimedia technology for better development. with its advantages, it will carry out a variety of innovative models such as personalized and professional services, promote the deep integration of multimedia technology and ice and snow sports tourism, and thus cultivate a modern ice and snow sports tourism model [2]. factors restricting the development of ice and snow sports tourism in china higher professional requirements for relevant professionals skiing and skating are both dangerous. when china's ice and snow sports tourism is developing rapidly, the increase in the number of tourists shows that the management level of the scenic spot is obviously insufficient, which makes the management level of the staff in the scenic spot need to be further improved. the increase in demand for ice and snow tourism requires high professional ability of the staff. china's training of innovative talents in sports tourism is relatively insufficient. the training mode of comprehensive talents cannot meet the wide application of multimedia technology, and the service quality of ice and snow sports tourism is also obviously poor. while developing the ice and snow sports industry, it is necessary to cultivate high-quality talents with professional skills of ice and snow sports. ice and snow coaches and snow makers are important factors for the development of the ice and snow tourism industry. our country has relatively insufficient talent training power for ice and snow sports. the degree of integration of ice and snow sports and tourism industry is not high, and the number of composite talents is not large, so we need to pay attention to them. the penetration rate of ice and snow population is relatively low when measuring the national penetration rate of skiing, it is mainly to observe the ratio between the total number of skiers and the total number of skiers. there is still a certain gap between the penetration rate of skiing in china and that in developed countries. in most cases, the enterprise managers of ice and snow tourism destinations take "market share" as the standard to measure the development of enterprises, and pay less huang qi exploring the potential of ice and snow leisure sports tourism in china 3| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset attention to the product connotation. in china, there are not many ice and snow sports venues and facilities, and the overall service level also needs to be improved. the ice and snow sports tourism industry contains only a few types of products. the existing products and brands cannot meet the needs of highquality sports tourism consumption, which is also an important factor in the low penetration rate of ice and snow population. inadequate understanding of ice and snow sports tourism the development and popularization of ice and snow sports tourism need a long process. ice and snow sports tourism is a kind of activity with high consumption, which is related to people's consumption level and consumption consciousness. however, the current public awareness of ice and snow sports tourism is not sufficient, the interest and attention of ice and snow sports tourism is not high, and a more effective concept of ice and snow sports and tourism consumption has not been formed. the consumption of ice and snow sports tourism is limited. application of multimedia technology in ice and snow sports tourism multimedia technology is a technology that enables users to carry out real-time information interaction with computers through a variety of senses on the basis of computer's comprehensive processing and management of text, image, animation and other multimedia information. multimedia technology is also known as computer multimedia technology. the application of this technology to ice and snow sports tourism has a positive impact on the development of ice and snow sports tourism. optimize talent training mode by using multimedia technology in the internet era, the integration of internet platforms and big data technologies with various industries has gradually deepened, and multimedia technology has also become an important driving force for the development of ice and snow talent training. the large-scale related technologies of ai technology and big data driven technology are promoting the reform of education and training models. by using multimedia technology, more mathematical scenes have been expanded, making the traditional teaching model gradually transform into a model of information content sharing [3]. at the same time, we will learn from and draw on the management and training experience of advanced snow sports talents at home and abroad, fully meet the current domestic demand for snow and ice talents, and effectively improve the training level of snow and ice talents. customizing ice and snow sports tourist services with digital technology with the increase of the number of ice and snow sports tourists, groups of all ages have become important participants in ice and snow sports tourism activities. the span of age levels is also larger, which brings challenges to the service level of scenic spots to a certain extent. traditional services have no way to meet people's needs. when building the ice and snow sports tourism digital service platform, analyze the data information of users' personal needs to achieve personalized services, so that tourists can get more information about ice and snow sports tourism, and quickly carry out the positive interaction of various sectors to improve tourists' tourism satisfaction. in addition, the multimedia platform has become the direction of ice and snow tourism market development, select unqualified tourists based on intelligent devices to ensure the safety of tourist groups. when multimedia technology enables tourist services, the transformation of thinking mode should be applied to finally realize the intelligent and scientific operation of the ice and snow sports tourism industry and the high-quality and quantitative development of services, meet the needs of industrial innovation and development, improve the satisfaction of tourism groups, and attract more tourists. use multimedia technology to enrich the participation mode of ice and snow sports tourism multimedia technology enriches the participation mode of ice and snow sports tourism, builds an ice and snow simulation system supported by multimedia technology, realizes the virtual implementation of ice and snow tourism, effectively promotes the digitalization of ice and snow resorts under the support of a simulation system composed of a control system, a multimedia system and other multi-function systems, and fully meets the needs of ice and snow sports tourists while improving their ski technology, in addition, it can effectively realize the real reproduction of the scene, provide snow simulation and other related resources for regions with insufficient snow and ice resources, and provide intelligent support for the overall process of skiers. at the same time, we should enrich the types of ice and snow tourism activities. in the form of participation in various types of ice and snow sports tourism, we should combine digital technology to meet the market's personalized demand for ice and snow sports tourism, so that ice and snow sports tourism will not be limited by ice and huang qi exploring the potential of ice and snow leisure sports tourism in china 4| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset snow resources, and provide tourists with the necessary fun of ice and snow sports tourism activities through scientific and technological means. using multimedia technology to improve the operation and management intensity of ice and snow sports tourism in the context of the extensive application of multimedia technology, the development of ice and snow sports tourism activities needs to improve the coordination ability, and the coordination ability needs not only to focus on the improvement of the internal coordination ability of ice and snow sports tourism management, but also to clearly connect external factors. by building a multimedia digital platform for ice and snow sports tourism, the comprehensive management of ice and snow sports tourist attractions will be carried out to a greater extent from all aspects. during the safety management of ice and snow sports tourist attractions, humidity modules, temperature modules and lcd modules are installed inside the scenic spots to better understand the activity routes of passengers. the multimedia platform can shorten the safety warning time to a greater extent and fully improve the management efficiency of ice and snow sports tourist attractions. at the same time, based on the customized 5g+ar immersive intelligent crowd guidance service system and 360 degree panoramic image acquisition technology, tourists can solve the problems existing in the process of sightseeing, so that tourist groups can understand the actual situation of the site and the passenger flow, and tourists can choose the appropriate site according to their own level. in the process of supporting service management, the integration of infrastructure and services, independent software developers and other aspects should be combined to better create an offline data integration approach, promote the combination of online platforms and offline tourism, and further expand the function of ice and snow sports tourism. in the multimedia platform, tourism groups can get the dynamic information content of ice and snow sports tourism destinations, such as navigation, shopping guide, catering and accommodation, under the support of multimedia technology, we will carry out activities such as buying tickets and entering the park, solve the problem of insufficient human resource allocation in each scenic spot, and improve the overall management level of the scenic spot. insist on market demand orientation and deeply develop new products in general, the development of ice and snow sports tourism products is from the whole process of product marketing and consumption. ice and snow sports tourism scenic spots should also pay full attention to the added value of ice and snow sports tourism products, build a well-known ice and snow brand, make full use of short videos, wechat platform and other multimedia boxes to promote ice and snow sports tourism products, and realize the publicity of ice and snow sports tourism products in multiple directions. under the background of market demand, develop ice and snow sports tourism products such as chemistry and ice and snow fishing, fully meet the spiritual needs of tourists, enhance product supply, and to a greater extent enhance the added value of the ice and snow sports tourism industry, making the ice and snow tourism industry chain more rich. conclusion the maturity of multimedia technology can also provide the basic conditions for the construction of the ice and snow sports tourism industry internet, while changing the development mode of the ice and snow sports tourism industry. the highly developed information technology-based ice and snow sports tourism industry provides a perfect network chain. this network relationship is not an economic entity in the legal sense, it does not have the legal personality, but needs to break through the boundaries between traditional enterprises, form an internet model of integrated development. the internet transformation of the ice and snow sports tourism industry not only needs to adopt the multimedia management platform, but also needs to innovate and further improve the quality of the original products and resources, and needs to adjust the management structure between the ice and snow sports tourism projects and the various industrial units of the multimedia platform. under the support of multimedia technology, the advantages of the project are combined to fully meet the economic and social benefits of the ice and snow sports tourism project. in the era of multimedia, the speed of information transmission has been unable to be expected. under the new development background, sustainable development thinking is required. the combination of ice and snow leisure sports and tourism industry in china enables multimedia technology to promote the integrated development of ice and snow leisure sports and tourism industry. during the application of multimedia technology in ice and snow sports tourism projects, supported by the multimedia platform, the diversified and multi-dimensional huang qi exploring the potential of ice and snow leisure sports tourism in china 5| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset publicity of the continuous output of ice and snow leisure sports culture enables the public to better receive information about ice and snow leisure sports culture through the all media platform, which enables multimedia technology to promote the construction of high-level composite talents with chinese characteristics and knowledge of ice and snow leisure sports and tourism industry, under the support of the multimedia platform, a multi-party information communication platform will be built in combination with internet technology to integrate ice and snow sports resources and tourism resources according to the characteristics of the region, strengthen infrastructure construction, and clearly expand the venues with ice and snow leisure sports functions that can be experienced by more consumers, so that the ice and snow sports tourism projects will be improved accordingly to better meet people's tourism needs. references [1]. gu jiuxian. research on regional consumer demands and behavioral influence of the 2022 winter olympics—hebei winter sports tourism as example [j] sports & research, 2016, 37 (04): 114-120. [2]. shi shuqi. research on the application of new media in the winter olympic games -a case study of "snow and ice in china" app [c] //. compilation of papers of 2017 science and technology winter olympic forum and sports science and technology product exhibition. [publisher unknown], 2017: 7779. [3]. tong gang. exploration on the construction of national snow and ice sports culture under the background of the dream of strengthening china [j]. snow and ice sports, 2015, 37(04): 64-67+84. 060210-f538-fap-521689-academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.1, issue 1; march -2023; https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 15| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset applications of discrete unit method in simulation analysis of loader shovelling mechanisms xiaoyuan zhang*, jijiang zhao, songsheng duan & zijiang wu school of intelligent engineering, jinzhong college of information, jinzhong, 030800, china abstract: loader shovelling mechanisms are used in various industrial applications, and the resistance encountered during the shovel loading process greatly affects the loading efficiency. shovel loading resistance is the reaction force of the material on the bucket during the shovel loading process and contains two parts: the resistance of the bucket insertion stage and the resistance of the lifting stage. therefore, it is essential to conduct research on shovel loading resistance to improve the performance of the loader shovelling mechanism. this paper presents a simulation analysis of the loader shovelling mechanism using the discrete element theory and edem software. a simulation model of the loading process is established, and the forward and reverse shovel loading processes are simulated. the mechanical characteristics of the shovelling operation are analysed visually, and the obstructing effect of the material on the bucket is clarified. the shovelling resistance of the key parts of the bucket at different stages of the shovelling process is specifically analysed, and the parts where the peak shovelling resistance is located and the stages where it is located are identified. the influence of the shovel angle on the resistance is also analysed. the results of the simulation analysis provide insight into the shovel loading resistance and the performance of the loader shovelling mechanism. the study demonstrates that the discrete element method can be effectively used in the simulation analysis of loader shovelling mechanisms, providing a useful tool for the design and optimisation of the loader shovelling mechanism. in conclusion, this research sheds light on the important mechanical characteristics of the shovel loading process and provides a comprehensive analysis of the shovelling resistance encountered by the loader shovelling mechanism. the results of this study can be applied to improve the design and performance of the loader shovelling mechanism, which can have a positive impact on various industrial applications that rely on this technology. keywords: shovel loading resistance, discrete element theory, edem software, simulation model, loading efficiency, mechanical characteristics, obstructing effect, peak shovelling resistance, shovel angle. introduction the discrete unit method is to view the medium as a set of discrete independent moving units and to build a mathematical model through the properties of the discrete body, treating the object of analysis as a discrete particle, which corresponds to the properties of the discrete body itself. edem software is based on the discrete unit method and is widely used in many fields to calculate simulation processes quickly and efficiently. the software allows detailed analysis of the simulation results, such as graph types, particle tracking, transient analysis, etc. yang study loader shovelling mechanisms. includes the shovelling operation process and the theoretical basis[1]. based on the discrete element principle, pang lizhi studied the bucket wheel pick-up process. taking the pick-up machine of a power plant as the research object, he applied edem software to simulate the horizontal pick-up process[2]. wang proposed the use of recurdyn to construct the loader model, and the use of edem to construct the material model, and carried out the coupling simulation mailto:topacademicjournals@gmail.com https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav77oq0bsntxyki_fpuey0ory1srzjf6gzzawscnovv0zyn5hf0vsyinzepdhwjqi_y0nhju_gob74glafldonvczkqsqxly5fy=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav5q_fe6vsc70eilciz6brgrqashumde22trzz6vjotpjwedppuycintfvytu30dhkqlxtynteofkitgiwtna7lxgtnavhzsnhe=&uniplatform=nzkpt xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 16| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset analysis of recurdyn-edem to study the coupling effect between the loader working device and the material under different trajectories[3]. zheng according to the collapsed material working conditions occurring in the actual operation of the material extractor, the bucket wheel excavation edem simulation model was established by studying the bucket wheel three-dimensional model, combined with the discrete unit method; the time course curves of the excavation resistance of multiple buckets in the material collapse process, under different deep burial conditions and in different directions were calculated, and the calculated values of the bucket wheel excavation resistance in the design specification were compared to assess the hazards of the maximum excavation resistance under different deep burial conditions[4]. li through data processing and setting of simulation parameters, a shovel loading model was established in edem software for shovel excavation conditions, and the accuracy of the model was verified by experimental and simulation methods; afterwards, the shovelloading process was simulated, and the resistance of different parts of the bucket at different stages of shovel loading was analysed to find out where the peak of shovel loading resistance was located[5].the characteristics of the bulk material and the loading conditions of the loader were analyzed by yu, the characteristics of the rock material were introduced, the calculation methods for calculating the operating resistance were summarized, and the factors influencing the size of the loading resistance were classified in the shovelling process, and the main factors were grasped for analysis [6]. bucket model the bucket is an important actuator for loading, transporting and discharging materials in the loader's working equipment. it is usually made of the front edge (sometimes equipped with bucket teeth), the bottom of the bucket, the circular bucket wall, the side edge, the side wall and the rear baffle welded together, and the shape in the transverse direction of the body remains basically unchanged, so the geometry of the bucket is determined by the longitudinal section size. at present, the bucket radius of gyration r is usually used as the basic parameter for the calculation of other parameters in the design, with the following formula. r= (1) r: bucket radius of rotation/m; vs : bucket flat capacity/m3 ; b0 : bucket internal measured width/m; λg: bucket bottom length coefficient; λz: back wall length coefficient; λk: baffle height coefficient; λr : radius of circle coefficient; γ: opening angle; γ1 : angle between baffle and back wall bulk materials consist of dispersed particles with a bulk substance that is not normally found in solids, liquids and gases, and whose garments of motion follow newton's second law [7]. under the action of internal forces, the particles of an object device undergo some kind of flow and take on the characteristics of a liquid, eventually forming a particle flow. in our daily life there are mainly gravel, sand, coal and grains, of which gravel, sand and coal are of most interest. the general rock materials are granite, limestone, sandstone, shale, etc. the characteristic features are different and table 1 shows the relevant physical properties of crushed rock [8]. table 1: physical properties of aggregates properties numerical values properties numerical values modulus of elasticity e 1.5 x 108 n/m2 resistance factor 0.20 density 1.9 x 103 kg/m3 coefficient ostatic friction 0.90 friction angle 32.5° rolling friction coefficient 0.66 poisson's ratio 0.35 [ ] − − − + ) 180 0.5(1 2 cos 0.5 cos 2 1 k 0 γ π γ λλγλ r z s b v https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav6wx5ktkniv0sp4dxvxkr11jfybktscbdfadtylqcucg4tfzhubh8-tqk6t7vcasopihblcrae-ikpb8_bmq3wzxn3-ii9e960=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav6wx5ktkniv0sp4dxvxkr11jfybktscbdfadtylqcucg4tfzhubh8-tqk6t7vcasopihblcrae-ikpb8_bmq3wzxn3-ii9e960=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav65l8icod58aicipvz23ssvkiy4rbjf3tut-gzjgdmtc15azkfaicqdkti_rj2bvm65ioatw30bce94wdnc5mxwgf-edugcen0=&uniplatform=nzkpt xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 17| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset non-adhesive spherical particle contact forces (hertz theory) the contact model is an important basis for modelling the discrete element method, its description of the contact behaviour between elements and the analytical calculations directly determine the magnitude of the forces and moments applied to the particles. therefore when using the discrete element method for different objects, the contact models differ and the results vary, but all simulation models must include at least one basic particle-to-particle and particle-to-geometry boundary contact model [9-12]. in this paper, in order to simplify the simulation, the default contact model hertz theory model set in the edem software is used uniformly, which has an efficient and accurate computational performance. hertz contact theory assumes that the surfaces of particles in contact with each other are smooth and homogeneous, that the contact surface is small compared to the particle surface, that only elastic deformation occurs at the contact surface, and that the contact force is perpendicular to the contact surface [13-14]. the hertz contact theory is the theoretical basis of the problem and is applicable to the elastic contact of curved bodies such as spheres, columns and ellipsoids, and even to the contact of micro-convex bodies between contact surfaces. as shown in fig.1, two spherical particles of radii r1 and r2 are in elastic contact, and the normal overlap α is α = r1 + r2 -|r1 -r2 |>0 (2) the radii of particle 1 and particle 2 are r1 , r2; r1 and r2 are the spherical position vectors of the two particles respectively. the dotted line in figure 1 shows the location of the particle surface when no deformation is considered, and the contact surface between the particles is circular, then the contact surface radius a is: a= ar* (3) the inter-particle normal forces n are: 1 3 n=e r*( *) 2α 2 (4) r* and e* are the effective particle radius and effective modulus of elasticity respectively. 1 1 1 = + (5) r* r r1 2 1 1−ν12 1−ν22 = + (6) e* e1 e2 e1,v1,e2,v2 are the modulus of elasticity and poisson's ratio of particle 1 and particle 2, respectively. when the increment of overlap between two contacting particles is δα, the increment of normal force δn is calculated from (4) or (5). ∆ =n 2 αr e* *∆ =α 2a *e∆α (7) analysis of forward shovelling resistance forces on the bucket in the x, y and z directions the forces on the bucket in the x, y and z directions are first analysed. in the simulation, a certain number of gravel particles are loaded into the bucket. the bucket is first shovelled into the rubble pile and then the bucket filled with rubble leaves the pile. the software offers linear translational rotation, sinusoidal translational rotation and convey or translational rotation. therefore, here we use linear translation and rotation. first, the bucket is shovelled parallel into the pile to a certain depth, then the bucket is turned over and lifted up. figures 2, 3, 4 and 5 show the variation of forces in the x,y and z directions versus time. where the full shovelling process is 15s. the horizontal axis represents the time of shovelling and the vertical axis represents the amount of shovelling resistance applied in each direction. xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 18| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: particle contact deformation diagram figure 2: shovel loading simulation analysis of figure 3 shows that the resistance of the bucket in the x-axis direction exceeds 9kn when the bucket is just shovelling into the rubble pile, there are small fluctuations in the resistance during the process of shovelling into the rubble, but when the bucket is filled with rubble the resistance rises rapidly to 12kn when the bucket is turned over and lifted off the pile, then the maximum partial force falls rapidly to the lowest resistance corresponding to the bucket shovelling out of the rubble pile. the x-directional force then does not change much. the peak force is generated in approximately 1.5s. figure 3: x-directional component of shovel loading resistance the peak force is approximately 1.5 s. the corresponding force in the z-axis in figure 5 is not very large compared to the x and y-axis. y-axis is not very large. the rest of the time is very smooth. the z-directional force is much smaller than the xand y-directions. figure 4: y-direction of the shovel load resistance 2 a a 2 5 8 time/s 12 11 10 9 x a x is f o rc e/ k n 2 5 8 time/s -8 -9 -10 -11 y a x is f o rc e/ k n xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 19| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: z-directional component of shovel loading resistance force analysis of the bucket base plate as the forces exerted on the base plate are the greatest during the shovelling process, the next discussion will focus on the base plate and the left and right plates of the bucket will not be analysed for the time being. simplifying the actual shovellingprocess of the loader, the shovel-in phase lasts 7 seconds and the bucket speed is 0.2 m/s; the effective working phase lasts 4 seconds and the angular speed of the bucket is 0.15 arc/s. the forces exerted by the material on the bucket floor during the horizontal shovel-in phase are shown in figure 6. the forces exerted by the material on the bucket during the bucket reversal lift are shown in figure 7. figure 6: bucket forces in the horizontal shovel-in phase figure 7: bucket stress diagram in lifting phase the analysis of the shovel loading resistance during the horizontal insertion phase showed that during the horizontal insertion phase the total force at the bottom first increased, then decreased and finally stabilised, 3 5 7 time/s 3.5 3 2.5 2 f o rc e/ k n 7 9 11 time/s 2 1.5 1 0.5 f o rc e/ k n xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 20| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset with local fluctuations during which it showed a secondary peak. the maximum force was 3.5 kn. in the subsequent stages, the force gradually stabilised when the amount of material loaded reached a threshold. as the bucket rotates upwards, the forces previously concentrated at the bottom of the bucket are gradually transferred to the circular wall of the bucket during this phase, so that the forces acting on the bottom of the bucket are significantly reduced during this phase. results of reverse shovel analysis forces on the bucket in the x, y and z directions figures 8, 9 and 10 show the relationship between the total force applied to the bucket during excavation in the x, y and z directions as a function of time. where the full shovelling process is 14s. where the horizontal axis indicates the digging time and the vertical axis indicates the magnitude of the digging resistance applied in each direction. figure 8: x-directional component of the digging resistance the relationship between the x-directional force and time can be seen in figure 8. the resistance of the bucket in the x-direction was just over 7kn when the bucket was just shovelling into the rubble pile, and its xdirectional force reached its maximum value of 9.8kn around the 8th s. between 5.5s and 8s, the bucket force had a more obvious fluctuation. as the time increases, its digging resistance gradually decreases, and after 9s its resistance drops significantly. figure 9: the y-directional component of the digging resistance 3 9 6 time/s 10 9 8 7 x a x is f o rc e/ k n 3 6 9 time/s -10 20 15 -25 y a x is f o rc e/ k n xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 21| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 10: z-directional component of the digging resistance from the results of the y-axis force splitting simulated in figure 9, it can be seen that the bucket's force splitting decreases gradually from 3 to 7.5s, reaching a minimum of -25kn, and gradually increases after 7.5s. after 6s, the force varies considerably, especially between 7 and 7.5s, when the trend of force decrease is extremely obvious. the results of the z-directional forces simulated in figure 10 show that the bucket's digging resistance gradually tends to increase from 3s onwards, reaching a peak of 32kn at around 5s, and then showing a decline to a minimum of 8kn at the initial resistance. force analysis of the bucket base plate the following analysis of the horizontal insertion phase of the excavation resistance analysis, in edem derived from the bucket bottom part in the horizontal insertion phase of the force diagram as figure 11, horizontal insertion phase, the bucket bottom overall force first increase and then decrease, local fluctuations. in the later stages, the forces are gradually stabilised as the amount of excavated material has reached its limit. as the bucket is turned upwards, the bucket floor, which previously bore the main part, is gradually shifted to the circular wall at this stage, so that the forces on the floor at this stage are on a decreasing trend, as shown in figure 12. figure 11: bucket forces in the horizontal insertion phase 3 6 9 time/s 32 24 16 8 z a x is f o rc e/ k n 10 12 14 time/ 12 11 10 9 f o rc e/ k n xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 22| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 12: bucket forces during the pick-up phase effect of shovel entry angle on resistance when shovelling horizontally, the bucket is shovelled into the rubble pile at a natural horizontal ground level, but due to the influence of the front teeth of the bucket, the bottom plate of the bucket is tilted at a certain angle to the horizontal surface and cannot achieve true horizontal; while shovelling into the rubble pile at a certain angle, the bottom plate of the bucket must be at a certain angle to the horizontal surface. when the shovel entry angle is less than 11°, the simulation result is close to the calculated value. in particular, when the shovel entry angle is between 5° and 10°, the two almost coincide. therefore, we analytically derived the process of shovelling the bucket into the rubble pile, where 7° and 9° were targeted, in order to obtain the best insertion angle. as shown in figure 13, it is concluded that the shovel entry resistance increases with increasing shovel entry depth, and with increasing shovel entry angle. when the shovel penetration depth is 0.3 m, the effect of the shovel penetration angle on the shovel penetration resistance is relatively small; when the shovel penetration depth exceeds 0.5 m, there is a significant increase in the shovel penetration resistance. figure 13: resistance variation curve conclusion based on the discrete element theory, this paper applies edem software to establish a simulation model of the loading process and realise the simulation of the forward and reverse shovelling operation process. through the simulation, the shovel resistance of different parts of the bucket at different stages of the shovel loading process is analysed, and the parts where the peak shovel resistance is located and the stages where it is located are identified. the resistance of the bucket in the x, y and z directions was analysed in the forward and reverse shovelling process. according to the force analysis of the bucket, the force on the bucket floor is the largest, after which the force analysis of the bucket floor during forward and reverse shovelling was carried out to obtain the trend of force changes. finally, the influence of the shovel entry angle on the resistance was analysed. it can be seen that when the shovel entry angle is 9°, the resistance increases with the depth of shovel entry. 3 6 9 time/ 24 18 12 6 f o rc e/ k n r es is ta n ce /k n 2 1.5 1 0.5 bucket penetration 0.2 0.4 0.6 shovel-in angle 7° shovel-in angle 9° xiaoyuan zhang*, jijiang zhao, songsheng duan, zijiang wu applications of discrete unit method in simulation analysis of loader shovelling mechanisms 23| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset acknowledgements this paper was supported by①“2022 science and technology innovation project for higher education institutions in shanxi province (2022l659)”②“2022 innovation and entrepreneurship project for students in shanxi province(20221640)” references [1]. yang zikang. research on resistance reduction shoveling strategy of loader based on edem [d]. jilin university, 2022. [2]. pang, l. c.. research on the bucket-material interaction mechanism of bucket wheel stacker bucket based on discrete element method [d]. jilin university, 2022. [3]. wang shaojie, yin yue, yu shengfeng, hou liang. simulation analysis of loader coupling dynamics based on recurdyn-edem [j]. machine design,2021,38(11):1-6. [4]. zheng pei, song wenxi, hu xiong. edem simulation of excavation resistance of bucket wheel stacker reclaimer under collapsed material condition [j]. sintered pellets, 2019,44(06):50-54. [5]. li r, xu wubin, li bing, yang xu. research on discrete unit method for bucket shovel resistance of loader [j]. journal of guangxi university of science and technology,2017,28(03):77-82. [6]. yu, xuebang. simulation study of loader bucket operation resistance based on edem [d]. guangxi university of science and technology, 2018. [7]. seife c. can the laws of physics be unified? science,2005,309(5731): 82-82. [8]. yan bo, zhan kai, guo xin, li hengtong, shi xiaojie. simulation study of underground scraper shoveling process based on edem [j]. nonferrous metals (mining part),2019, 71(06):74-77. [9]. sun qc, wang gq. introduction to the mechanics of particulate matter. beijing:science press, 2009. [10]. sun qicheng, hou meiying, jin feng. physics and mechanics of particulate matter. beijing: science press, 2011. [11]. jaeger hm, nagel sr, behringer rp. granular solids, liquids, and gases. reu modern phgs, 1996, 68(4): 1259-12734. [12]. kadanoff lp. built upon sand: theoretical ideas inspiredby granular flows. rev modern phys, 1999, 71(1): 435-4445. [13]. de gennes pg. granular matter: a tentative view.revmodern phys, 1999, 71(2): s374-s382. [14]forterre y, pouliquen o. flows of dense granular media.annual review flauid mechanics, 2008, 40: 1-26. academic journal of science, engineering and technology vol.1, issue 1; march -2023; https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 30| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the rise of digital twin technology: advantages, applications, and key technological developments yuxizi zheng, xuemei wang, zhe xu & shuo guo xi'an research inst. of hi-tech, xi’an, china abstract digital twin technology has emerged as a key means to promote intellectualization and digitalization in various fields. it is a technical means based on simulation, with the integration of data and model as the core. this paper provides a brief overview of the development history and definition of digital twin, proposes that digital twin consists of three basic components: physical layer, transmission layer, and virtual layer, and explains the key technologies involved such as sensing and monitoring, complex system modeling, and big data analysis. the current research on digital twins is summarized, including theory, data, and technology. typical applications of digital twins in industrial manufacturing, smart cities, aerospace, and other aspects are described. finally, the paper looks forward to the development trends of digital twin technology. digital twin technology offers real-time, reusable, and intelligent solutions for product design, experimental data collection, experimental result analysis, and prediction. the advantages of digital twin technology have been recognized by many countries, including the united states, the united kingdom, and china. as digital twin technology continues to evolve, it is expected to play an increasingly important role in the construction of digital china and the advancement of other countries towards digitalization. this paper highlights the need for further research on the key technologies of digital twin to promote its application and development. keywords: digital twin, simulation, data integration, real-time, reusable, intelligent, sensing, monitoring, complex system modeling, big data analysis, industrial manufacturing, smart cities, aerospace, development trends. introduction with the continuous advancement of intelligence and digitalization in various fields, digital twin technology has received more and more attention. the united states takes digital twins as the main carrier, focusing on military and large-scale equipment and other fields; the uk has set up a digital construction center with plans to build a national twin; in 2020, china also wrote digital twins into the "14th fiveyear plan", which became an important part of the construction of digital china. as an important technical means to improve production efficiency, digital twin has great advantages in product design, experimental data collection, experimental result analysis and prediction, etc., and the research on key technologies of digital twin to promote its application and development will effectively promote china's digital process. 1. the evolution of digital twins at the beginning of the twentieth century in the aerospace field, due to high manufacturing costs, complex design, inconvenient flight test data collection and other problems, in the process of product design and development, the concept of "simulation" appeared. early simulations focused on physical mapping of entities to describe the internal characteristics or environmental conditions of the system. with the rapid development of computer technology, simulation technology has gradually developed into all-digital simulation based on mathematical models. however, there may be a large modeling error or inability to model the physical object in the all-digital simulation, so it is tried to connect the physical object in a certain part of the simulation loop mailto:topacademicjournals@gmail.com yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 31| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and test it under the conditions that meet the overall system performance, resulting in semi-physical simulation. in the early eighties, "virtual reality" technology was proposed, which refers to simulating the environment through computers, so that participants can have different sensory experiences and understand the objective world from the virtual environment. due to the interactivity and realism of virtual reality technology, simulation technology has been greatly developed. with the continuous maturity of a new generation of information technology and its deep integration with simulation technology, digital twins have emerged. in 2002, professor michael grieves of the university of michigan introduced two systems, real and virtual, when demonstrating product lifecycle management [1], which laid the foundation for the emergence of digital twins. subsequently, professor grieves proposed the concept of "digital representation of physical products in physical space". in 2010, the term "digital twin" was officially proposed in nasa's technical report and defined as "the simulation process of a system or aircraft that integrates multiple physical quantities, multiple scales, and multiple probabilities" [2]. in 2012, nasa and afrl defined a digital twin for an aircraft as an integrated multiphysics, multiscale, probabilistic simulation model for an aircraft or system that utilizes the best available physical models. updated sensor data and historical data, etc., to reflect the state of the flight entity corresponding to the model [3]. as an important tool to improve efficiency, digital twin can effectively promote the integration and development of digital economy and real economy. 2. the basic components of a digital twin according to the different definitions of digital twin, the composition of common digital twin systems is proposed as shown in figure 1, which is mainly divided into physical layer, transport layer and virtual layer. figure 1: basic components of the digital twin system 2.1. physical layer the physical layer consists primarily of modeled objects and sensing systems in physical space. modeling objects mainly include entities, various equipment, and operating environments; the sensing system mainly relies on various sensors to perceive and measure the operating state of the modeled object, and at the same time monitor the operating environment and collect data in real time. the physical layer involves sensing and monitoring technology [4]. in a complete digital twin system, the acquisition of the operating environment and the state data of the digital twin components itself is an important part of the accurate mapping and real-time interaction between all elements, all states and the whole process between physical objects and their digital twin systems. in order to establish a comprehensive iot perception system and achieve accurate monitoring of the operation situation of physical objects, perception technology needs to rely on more accurate physical measurement technology, and also need to consider the synergy between the perceived data on the surface or inside the system structure, a distributed sensor network is used to determine the spatial location and unique identification of the target to ensure that the equipment is trusted and controllable [5]. yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 32| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.2. transport layer the transport layer is the bridge that connects the physical layer and the virtual layer. the transport layer transmits the physical operation data obtained by the sensing system to the virtual layer, realizing real-time mapping from the physical layer to the virtual layer [6]; at the same time, the control instructions issued by the virtual layer are transmitted to the physical layer, thereby intervening in the operation of the entity, so that a two-way data flow is formed between the physical layer and the virtual layer. the creation and control of digital twins are based on data collected in real time, so the system needs to have faster information transmission speed and shorter latency. it can achieve high bandwidth, low latency, support distributed information collection, and have high security and high reliability. with the help of the internet of things, blockchain, 5g, quantum communication and other means, the information of the physical layer is transmitted quickly and accurately, and the security and reliability of information need to be guaranteed. 2.3. virtual layer the virtual layer is the core part of the digital twin system, which is the mapping of the physical layer in the digital space, containing a model as close as possible to the physical object and synchronized with the physical layer. the implementation of digital twin should be driven by data and supported by the model, and the twin model is a true description of the physical layer entity, mapping the physical layer from different dimensions and different aspects, so that the entity state is reflected in the virtual space. the twin data comes from realtime monitoring data and historical data at the physical layer, and is processed to drive the twin model. the establishment of virtual layer model mainly applies to complex system modeling technology. digital twin model includes visual model and mathematical model, by studying the structural composition and assembly relationship of physical entities, 3d max, solidworks and other threedimensional modeling tools can be used to establish the corresponding models of each part, and synthesize after verification to obtain a visual model reflecting the overall appearance, structure, size and other information of the physical object [7]. since the mathematical model has the characteristics of involving many disciplines, diverse forms, many types, and large quantities, it can be modeled according to the product composition relationship of different subsystems [8]. the connection and motion law of each subsystem of the physical object were analyzed, the corresponding mathematical model was abstracted by means of mechanism modeling or parameter estimation, and simulation tools such as matlab/simulink and modelica were used to carry out simulation research under different conditions and parameters [9]. in addition, the digital twin system can be more closely related to the actual system by modeling the environment and analyzing the operation status of the digital twin under different conditions [10]. the data received by the virtual layer usually has the characteristics of multiple types, large volume, and high application value. by establishing a corresponding database to store data, and using big data analysis technology, real-time screening and processing of data, fully activating and releasing data value, and exploring the interrelationship between different data to achieve the purpose of diagnosis, prediction and decisionmaking [11]. 3. current state of digital twin research at present, digital twins mainly include theory, data, technology, etc., as shown in figure 2. yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 33| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2: digital twin research direction in terms of theoretical research, zhuang cunbo [12] reviewed the background and concept of digital twin, and introduced the specific connotation of product digital twin. tao fei [13] aimed at the establishment of digital twin models, put forward the construction criterion of "four modernizations, four can be used in eight ways" of digital twin models, and carried out research and practice on the construction theory of digital twin workshop models. jia shiqi [14] summarized the current development of digital twin technology, summarized its practical results and future application directions, and looked forward to the needs and prospects of digital twin standardization according to the current standardization process. zhou junhua [15] analyzed the development process of digital twin technology, pointed out the necessity of applying digital twin technology to weapon system research and practice, and elaborated its concept and composition. zhang dawei [16] introduced the application of digital twin technology in equipment life cycle cost management, and pointed out the existing problems and solutions, so as to provide reference for improving the cost efficiency of equipment. in terms of technical analysis, liu yang [6] analyzed the connotation, development context and significance of industrial digital twin, focused on the development direction of industrial digital twin, and put forward several suggestions on its development. jiang haifan [17] put forward the concept of digital twin evolution model, and gave the application methods, key technologies and working platforms of the three evolution stages of digital twin. wang huixia [18] analyzed the main differences between digital twin technology and simulation technology, refined the key technologies involved in digital twin, and designed the basic framework and application mode of digital twin of launch vehicle control system. lu qing [19] discussed the application of digital twin technology in aircraft architecture model design, multi-model architecture integration, model parameter identification and verification, and provided important guidance and technical support for the development of aircraft models and integration tests. wang wei [20] analyzed the development and value of digital twin, elaborated the basic characteristics and architecture of digital twin, introduced the key technologies of digital twin on this basis, and finally looked forward to its development prospect. wu yan [21] based on digital twin technology, sorted out the concept of digital twin, and discussed digital twin technology in manufacturing. in terms of data processing, zhang suming [3] introduced a rocket test and launch process health management system based on digital twin technology, and carried out design optimization and performance analysis, realizing data analysis, diagnosis collaboration, and fault handling decision support. fan rui [22] discussed the application of digital twin technology in data monitoring of intelligent production systems, and discussed how to achieve an efficient combination of production site and production management. in order to solve the problems encountered in the modeling and data acquisition of digital twin workshop, zhou shuaichang [23] proposed to use the half-side folding algorithm to make the complex three-dimensional model lightweight, and the improved fuzzy c-means algorithm to improve the accuracy of the data. yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 34| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. typical applications of digital twin technology 4.1. application of digital twins in industrial manufacturing siemens has been closely following the development trend of industry 4.0 and intelligent manufacturing in germany, and has been committed to the development and application of digital twin technology in recent years, and has integrated digital twin technology into its digital strategy in the past two years. siemens uses digital twin technology to digitally design, optimize and validate production processes, modify plant layouts, select production equipment, optimize production processes, and more. the automation system is verified through virtual commissioning technology, enabling it to be commissioned quickly and efficiently on site. control the physical world in the virtual world, so that the entire workshop can achieve complete integration, so as to achieve efficient and reliable production; complete production planning, production execution and quality inspection through the manufacturing operation management system; with mindsphere, all machines and equipment can be monitored in real time to analyze and evaluate actual production. through analysis and forecasting, we can drive continuous improvement of actual production and products, thereby shortening the product design optimization cycle. in the application of machine tools, with the help of digital twin technology, enterprises can complete simulation and verification from cutting to maintenance and fault diagnosis in the digital world in advance during the development stage. it can not only save the debugging cost of mature models and extend the life cycle, but also improve the research and development efficiency of new models and reduce trial and error costs. for machine tool end users, digital twin software can be used to test cut and proofing parts without physical prototyping and environmental construction, which can significantly reduce the risk and cost of the machining process. in addition, users can also use the digital twin to train personnel and effectively avoid the risk of machine collisions caused by insufficient personnel experience by simulating the operating environment. 4.2. application of digital twins in smart cities urban digital twin is a technical means of simulating modeling and interactive control of the whole life cycle process of urban physical entities through the digital virtual mapping of the city, with the help of historical data, real-time data, spatial data and algorithm models, etc., which can express and present all elements of physical objects, relationships, activities, etc. in the urban physical space and social space in the digital space, so as to realize the comprehensive perception and precise control of the city and promote the intelligent and digital development of the city [24]。 during the construction of xiong'an new area, it proposed to "adhere to the synchronous planning and synchronous construction of digital city and real city", based on the theory of urban complex adaptation system, to build a digital twin of the city, so that the physical city and the digital city can be connected in real time and dynamic feedback, constantly track and identify the changes of the city, so that the "hidden order" of the city can be made visible, so as to better follow the law of urban development [25]. all elements of xiong'an new area will be built synchronously in the digital city according to the construction sequence, and updated with the development of the city, and jointly iterated, which is an ecosystem that can evolve. the biggest innovation of digital twin cities lies in the fact that physical cities and digital cities can coexist and grow together, and the virtual and real can be integrated. the digital twin technology is introduced into the urban flood disaster assessment and early warning system, and realizes the visual integration of the city by establishing an intelligent perception system covering all elements of urban flood disaster, integrating real-time data such as land, water system, and transportation. use data to realize the dynamic evolution of urban digital twin, drive urban flood disaster scenario simulation analysis and decision-making system, predict the development trend of flood disaster through intelligent algorithms, and automatically issue early warning signals when necessary. the optimized system solves the problems of insufficient perception and dynamic response ability of the original system and poor real-time decision-making, and integrates the functions of urban real-time rain monitoring, flood disaster assessment, disaster prevention simulation and early warning [26]. digital twin library refers to the use of physical model data and multi-scale simulation technology to comprehensively model the physical entities of the library in the virtual space in order to complete the iterative yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 35| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset optimization of all elements, holographic intelligent monitoring, and global intelligent construction. through the whole process of data mining, operation monitoring and integrated analysis of the physical entities of the library, a new model library that can realize intelligent interaction between virtual and real is built. its essence is to build the digital expression of the physical entity of the library, realize the extension of the full life cycle service of the library, carry out virtual and real interaction, tracking and analysis and two-way real-time mapping in the virtual information space, and maintain the synchronous update of data transformation, and accurately optimize the physical services, facilities and resources of the library [27]. 4.3. application of digital twins in aerospace in the design and development, manufacturing and assembly, operation and maintenance of aircraft, the introduction of digital twin technology can effectively shorten the development cycle and significantly reduce costs. by establishing a digital twin of the aircraft, the product testing and verification is completed virtually in the digital space, and defects are found in the design stage and the design is improved in time to avoid waste caused by repeated modifications [28]; in the actual production and manufacturing, the processing status of each part can be tracked in real time, and the existing manufacturing process can be continuously optimized through reasonable allocation of resources to reduce downtime; in the maintenance stage, sensors are used to monitor the status of the aircraft in real time, reflect the real flight conditions, and can realize the dynamic update of the model by combining intelligent algorithms, improve the prediction ability, and can also be used to diagnose the cause of abnormal situations and evaluate after the occurrence of failures [29]. the digital twin satellite is a collection of digital models with the same origin, data sharing, coevolution, realtime interaction, synchronization between heaven and earth, and extended survival of the physical satellite [30]. the digital twin satellite can reflect the formation process, real-time status and behavior of the physical satellite, and predict, evaluate and optimize the physical satellite in the digital space. it is the twin asset and efficiency multiplier of the whole life cycle and the whole value chain of the satellite product. on the basis of realizing the digital twin function of general aircraft, the digital twin satellite can also optimize the shape parameters and deployment process of the satellite solar wing using the entity data; and the use of digital twins for ground thermal test can further save the resources on the satellite [31]. the application of digital twins to rocket testing and launch processes can effectively improve the reliability of rocket launches. in the ground test stage, the ground digital twin system monitors and interprets the data of each instrument during the test, and at the same time identifies the abnormal data to assist the profession personnel make decisions; during the ignition take-off phase, the engine thrust status diagnosis is carried out, and the takeoff process will be performed only after the digital twin on the arrow and the ground judge that the rocket starts normally; in the rocket flight phase, the digital twin system regularly receives the data transmitted by the telemetry system, carries out real-time simulation prediction, accelerates the determination of alternative solutions when a fault is detected, and issues control instructions to the rocket to minimize the occurrence of failure [32]. 5. summary with the continuous deepening of the research on digital twins by scholars from all aspects, the technology has made rapid development in recent years. however, in the application process of digital twins, there are still problems such as the lack of unified standards, the lack of interdisciplinary integrated design platform, and the need to further improve the application of core technologies. therefore, most of the current work is concentrated in the theoretical research and experimental verification stage. nevertheless, because of the great advantages of digital twins such as virtual-reality mapping, real-time synchronization, symbiosis and evolution, it is of great significance to study its key technologies, break through the difficulties encountered one by one, and promote its application in manufacturing, aerospace, urban management, smart medical and other fields to promote china's digital process. references [1]. dong leiting, zhou xuan, zhao fubin, et al. key modeling and simulation technology of digital twin of aircraft structure [j]. journal of aeronautics, 2021, 42(3): 113-141. yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 36| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [2]. wang falin, guo yaowen, gong jianhua, et al. dynamic construction method of cable assembly process model for complex electromechanical products based on digital twin [j]. computer integrated manufacturing systems,2022: 1-22. [3]. zhang suming, yue mengyun. research on health management technology of rocket test and launch process based on digital twin [j/ol]. computer measurement and control, 2021, 29(5): 814. [4]. meng songhe, ye yumei, yang qiang, et al. digital twin and its application in aerospace[j]. journal of aeronautics, 2020, 41(9): 6-17. [5]. liu yang, zhao xu. research on industrial digital twin technology system and key technologies [j]. information and communication technology and policy, 2021, 47(1): 8-13. [6]. du yingying, luo ying, peng yibing, et al. 3d visual monitoring of industrial robots based on digital twin [j]. computer integrated manufacturing systems,2022: 1-15. [7]. li hao, tao fei, wang haoqi, et al. integrated development framework and key technologies for design and manufacturing of complex products based on digital twin [j/ol]. computer integrated manufacturing systems, 2019, 25(6): 1320-1336. [8]. li kai, qian hao, gong mengyao, et al. digital ship based on digital twin technology and its application exploration [j/ol]. ships, 2018, 29(6): 101-108. [9]. ji guang, hao jianguo, zhang zhongjie, et al. twin simulation study of flight process of quadrotor uav [j]. computer engineering and applications, 2022, 58(12): 66-73. [10]. laukotka f, hanna m, krause d. digital twins of product families in aviation based on an mbseassisted approach[j/ol]. procedia cirp, 2021, 100: 684-689. [11]. yin haijun, xiao tangwei, li xin. technical framework for digital twin workshop control of production line [j/ol]. modern manufacturing technology and equipment, 2021, 57(10): 1-6. [12]. zhuang cunbo, liu jianhua, xiong hui, et al. connotation, architecture and development trend of product digital twin [j/ol]. computer integrated manufacturing systems, 2017, 23(4): 753-768. [13]. tao fei, zhang he, qi qinglin, et al. theory and application of digital twin model construction [j/ol]. computer integrated manufacturing systems, 2021, 27(1): 1-15. [14]. jia shiqi, han li, qin chao, et al. research on digital twin application and standardization requirements [j]. information technology and standardization, 2021(11): 18-22+30. [15]. zhou junhua, xue junjie, li heyu, et al. some thoughts on digital twin of weapon system [j/ol]. journal of system simulation, 2020, 32(4): 539-552. [16]. zhang dawei. application of digital twin technology in equipment life cycle cost management [j]. command control & simulation, 2022, 44(3): 122-127. [17]. jiang haifan, ding guofu, xiao tong, et al. digital twin evolution model and its applications in intelligent manufacturing[j]. journal of southwest jiaotong university, 2022, 57(6): 1386-1394. yuxizi zheng, xuemei wang, zhe xu, mengting hou, yuanping dong, hang jiang & shuo guo the rise of digital twin technology: advantages, applications, and key technological developments 37| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [18]. wang huixia. research on digital twin technology and its application in space control[c/ol]. chinese society of simulation, 2021: 387-393. [19]. lu qing, wu shuang, zhao zhe, et al. application of digital twin technology in aircraft design verification [j/ol]. civil aircraft design and research, 2019(3): 1-8. [20]. wang wei, liu yongsheng, liao jun, et al. key technologies and architecture of digital twin [j]. post and telecommunications design technology, 2021(8): 10-14. [21]. wu yan, wang xiaojun, he yong, et al. review of key technologies and applications of digital twin in manufacturing industry[j/ol]. modern manufacturing engineering, 2021(9): 137-145. [22]. fan rui, liu qingchuan, gao jian. data monitoring technology of intelligent production line system based on digital twin [j/ol]. ic application, 2021, 38(11): 120-121. [23]. zhou shuaichang, liu lilan, gao zenggui. model and data acquisition optimization of digital twin workshop [j]. industrial control computer, 2021, 34(12): 14-16. [24]. national beacon committee smart city standards working group. white paper on urban digital twin standardization (2022 edition)[r/ol]. [2022-09-20]. [25]. zhou yu, liu chuncheng. the logic and innovation of building a digital twin city in xiong'an new area [j]. urban development research, 2018, 25(10): 60-67. [26]. li qiang. analysis of urban flood disaster assessment and early warning system based on digital twin technology [j]. journal of beijing university of technology, 2022, 48(5): 476-485. [27]. li jingmin, tang yi, li keyu. research on the application of digital twin technology in library construction [j]. information exploration, 2022(3): 77-82. [28]. cui yihui, yang bintao, fang yi, et al. application of digital twin technology in aero-engine intelligent production line [j/ol]. aero engines, 2019, 45(5): 93-96. [29]. zhang lei. research on predictive maintenance model of equipment based on digital twin [j]. special equipment for electronics industry, 2021, 50(3): 12-15. [30]. cui yufu, liu zianjia, wang jing. development and prospect of digital twin satellite technology [j]. space international, 2021(10): 27-31. [31]. cui yufu, liu zianjia, wang jing. digital twin satellite technology and engineering practice [j]. spacecraft engineering, 2021, 30(6): 62-69. [32]. zhang suming, yue mengyun. research on health management technology of rocket test and [33]. launch process based on digital twin [j/ol]. computer measurement and control, 2021, 29(5): 814. academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a critical examination of vector calculus: a logical approach akmal khurshidov home of physical problems, pisatelskaya tashkent, uzbekistan abstract: this study addresses the foundational aspects of vector calculus, acknowledging its widespread use in the natural sciences. while vector calculus has proven highly effective in various scientific applications, its validity and foundational underpinnings warrant formal-logical scrutiny. the absence of a comprehensive formal-logical basis challenges the assertion of vector calculus as absolute truth. this paper endeavors to fill this gap by conducting a critical analysis of vector calculus, employing the unity of formal logic and rational dialectics as the methodological framework. by subjecting vector calculus to this rigorous analysis, we aim to establish a solid foundation for this mathematical formalism. keywords: vector calculus, formal logic, rational dialectics, foundational analysis, mathematical formalism. introduction as is well known, the mathematical formalism of vector calculus is widely and successfully used in natural sciences [1-7]. however, this does not mean that the problem of validity of vector calculus is now completely solved, or that the foundations of vector calculus are not in need of formal-logical analysis. in my view, standard vector calculus cannot be considered as absolute truth if there is no formal-logical substantiation of this calculus. recently, there has arisen a necessity for critical analysis of the foundations of vector calculus. but there are no works devoted the analysis of vector calculus within the framework of the unity of formal logic and of rational dialectics. the purpose of the present work is to propose the correct analysis of the foundations of vector calculus. the analysis is carried out within the framework of the correct methodological basis: the unity of formal logic and of rational dialectics. 1. analysis of the concepts of “direction” and “vector" as is well known, in mathematics, physics, and engineering, a vector (or euclidean vector, or geometric vector, or spatial vector) is called quantitative characteristics which has not only a numerical value, but also the direction [7, 8]. in other words, vector is a line segment with a definite direction (or graphically is an arrow), connecting an initial point with a terminal point. i.e., vector is a geometric object that has magnitude (or length) and direction and can be added to other vectors according to vector algebra. physical examples of vector quantities are material point displacement, velocity and acceleration of a material point, as well as a force. therefore, analysis of the concept of “vector” is not possible without the definitions of concepts of “movement” and “direction”. 1. movement is a change in general, any interaction of material objects. category of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset “movement” is a scientific concept that reflects the most common and essential property of phenomena (processes), the most common and essential relations and connections in reality. movement is an attribute of matter. in accordance with the dialectical principle of the unity of matter and movement, the movement does not exist without material objects. but the movement is not a material object. the movement is manifested as the unity of opposites: changeableness and stability, continuity and discontinuity. concretization of the movement is the main forms of movement: mechanical, physical (thermal, electromagnetic, gravitational, atomic, and nuclear), chemical, biological, informational, and social ones. 2. change as a process can be of two types: a qualitative change and quantitative change. the qualitative change (i.e. a change of qualitative determinacy) is studied by dialectical logic and natural sciences. the quantitative change (i.e. a change of quantitative determinacy) within the limits of certain qualitative determinacy is studied by formal logic and mathematics. the quantitative change can be studied only within a reference system which contains a clock as component part. 3. a clock (i.e., a device containing a working clock mechanism, moving the arrow and the fixed dial) determines the time and time characterizes the clock. time is a concrete concept because it expresses the property of the clock mechanism (clock process). time t is a universal variable (with the dimension of “second”), an information basis that is used to put in order of information about events and processes in the world. time t is defined by the following mathematical expression [9]: tn n where n 0, 1, 2,...; is elementary (unit) duration which can be made as small as desired. concrete numbers (denominate numbers) tn have one and the same qualitative determinacy (i.e., dimension of “time”). the set of numbers tn forms an ordered sequence. a member of the sequence is called a moment of time. numerical values of quantity tn is changed due to clock mechanism which continuously changes numerical values of the quantity n . 4. the mechanical form of movement (in particular, the motion of a material point m ) is studied in a reference system which represents the unity of the system of coordinates and clock. the system of coordinates is a system of measuring devices which determines the position (i.e., the set of coordinates) of a material point m in space. (for example, the cartesian coordinate system represents the system of three connected measuring scales (drawing scales): straight linesox , oy , oz with printed concrete numbers (denominate numbers) having the identical dimension of “meter”). the space of the object (for example, geometric space, and energy space) is the set of possible (available) states of the material object (in particular, the set of positions of the material point m ). each state is characterized by a certain concrete number (denominate number) having a dimension. movement of an object in space is a process of transition from some states to other states, i.e. the process of transition from some concrete (denominate) numbers to other concrete (denominate) numbers. 5. a process has the beginning (i.e., the beginning of the changes) and the end (i.e., the end of the changes). the transition from the initial state to the final state represents the sum of elementary transitions and, therefore, is characterized by an increase of the changes. in other words, the total change is the sum of elementary changes. since elementary change is characterized by the concrete (denominate) number having a dimension, the total change has dimension as well and is expressed by the following mathematical formula: sn n , where n 0, 1, 2, 3, ..., is elementary (single) change which has the dimension and is mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assumed to be constant. the set of denominate numbers sn forms an ordered sequence. the numerical values of the denominate quantity sn are changed if the numerical values of the quantity n are changed. if the numerical values of the quantity n are not changed with time, the process is not realized. 6. a process is characterized by the direction (directivity) of change, the rate of change, and acceleration of change. if the process is not realized, the direction (directivity), the rate, and acceleration do not exist. explanation is that the direction (directivity), rate, and acceleration are the properties of the process and not the properties of the material object. therefore, the direction of change determines the order of the number set but an ordered number set does not determine the direction. neither pure mathematics nor applied mathematics (i.e., the mathematical formalism of the natural sciences) does not contain a mathematical (calculation) process because the mathematics does not represent a computer or some other material device that realizes the process of change of the values of the quantitysn . change of the valuesof the quantity n is carried out by an operator (person). therefore, the correct mathematical formalism cannot contain the concepts of “direction (directivity)” and “vector”. 7. if one assumes that the mathematical formalism contains the concepts “direction (directivity)” and “vector”, then the formula for the quantity sn to be written in the following vector form: sn n where is elementary (unit) vector. but since the numerical values of quantity n in this formula are not changed with time, the process of change of the numerical values of the quantity sn in mathematical formalism is not realized. therefore, this formula does not describe direction, and the mathematical formalism does not contain the concepts of “direction (directivity)”, “vector”, and “unit vector”. thus, the “direction (directivity)” and “vector” are not mathematical objects (concepts). the concepts of “direction” and “vector” do not correspond to any geometric object (for example, a line segment). indication of the boundary points of the line segment and designation of these points with the help of terms (words) ”beginning” (“initial point”) and “end” (“terminal point”) do not define mathematically a geometric vector (because the order of points do not define the direction of movement). all points of the line segment have one and the same qualitative determinacy: concept of “initial point” and concept of “terminal point” are identical ones. therefore, the terms “beginning” and “end” of the segment are not mathematical definitions of the concept of “direction (directivity)”. an arrow is a visual (graphic) image of course. in other words, verbal, literal, symbolic, numerical, and graphical representations (display) of the beginning and the end of the segment are not a mathematical definition of the concept of “direction (directivity)”. therefore, the correct mathematical formalism can not and must not contain the concepts of “direction (directivity)” and “vector”. the coordinate system represents a system of three connected drawing scales: straight lines ox , oy , oz, which cannot be attributed to the direction. also, straight linesox , oy , oz cannot contain the unit vectors. from the point of view of formal logic, the terms “direction (directivity)” and “vector” in mathematics and theoretical physics mean representation, i.e. imaginary image of the process, which is depicted with the help of an arrow. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset x cos v v x  2. analysis of the standard propositions of vector algebra the mathematical concept of “vector in generall” cannot be used in the natural sciences: this concept does not make sense in the natural sciences. the concept of “vector” as used in the natural sciences is characterized by the concepts of “denominate quantity” and “dimension of quantity”. therefore, analysis of the standard propositions of vector algebra must be done from this viewpoint. 1. as is known, the position of a vector in the cartesian coordinate system oxyz is determined by its projections. the projection of the vector on the axis is defined as follows. there are vector v whose module has the dimension (for example, the dimension of speed, acceleration dimension, the dimension of power) and the axis ox with the denominate numbers which have dimension of length. the projection of the vector v on the axis ox is called the quantity (module, length) v of directed segment vx located (placed, putted) on the axis ox : where is the angle between the vector v and the axis ox . in general case, the vector v is decomposed into components under the cartesian orthonormal basis i , j , k as follows: v vx i vy j vz k where i , j, k are the unit vectors of the cartesian coordinate system; vx , vy , vz are the projections of the vector on the corresponding axes. the principal importance of the basis i , j , k is that the linear operations on vectors under the given basis become the usual linear operations on numbers – the coordinates of these vectors. in my opinion, these standard expressions are not free from objection. the objection is that the standard expressions are contrary to the formal-logical laws. really, the standard expressions assert that segment vx lies on the axis ox (i.e., segment vx coincides with the segment of axis ox ). from the point of view of formal-logical law of identity, this implies that these segments have the same qualitative determinacy (i.e., the same sense, the same dimensions): (qualitative determinacy of the segment vx ) = (qualitative determinacy of the segment of the axis ox ). but the segment vx cannot lie on the axis ox (i.e., the segment vx cannot be coincided with a segment of the axisox ) because these segments have different dimensions and, therefore, different qualitative determinacy (i.e., different senses). this statement is expressed by formal-logical law of absence of contradiction: (qualitative determinacy of the segment vx ) (qualitative determinacy of the segment of the axis ox ). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset consequently, the mathematical operation of finding the projection of the vector v on the coordinate axes represents the formal-logical error: violation of the law of absence of contradiction. 2. as is known, the rule of addition of vectors having the same qualitative determinacy is called the “triangle rule” or “parallelogram rule”. standard operation of addition of two vectors is defined as follows: the sum v1 v2 of two vectors v1 and v2 is called the vector running from the beginning of the vector v1 to the end of the vector v2 under the condition that the vector v2 is applied to the end of the vector v1 . under the addition of two vectors, their projections on an arbitrary axis are added, and under the multiplication of a vector by any number, its projection on an arbitrary axis is multiplied by this number. in my view, these standard assertions are not free from objection. the objection is that the standard assertions are contrary to the formal-logical laws. really, segments of vectors and segments of arbitrary axis have different qualitative determinacy (i.e., different senses). this implies that the segments of the vectors v1 and v2 cannot lie on a segment of an arbitrary axis (i.e., the segments of the vectors cannot coincide with a segment of an arbitrary axis). from the point of view of formal-logical law of identity, these segments can be coincided if only they have identical qualitative determinacy (i.e., the same dimension, the same meaning). 3. as is known, the scalar product of two vectors v and f is defined as follows: (a) one brings the initial points of vectors in coincidence with each other (i.e., the initial points are connected); (b) one postulates the relation v f v f cos where the point between symbols of vectors denotes the operation of scalar multiplication of vectors, is angle between the vectors. the expression v cos represents a denominate number: the projection of the vector v on the vector f . also, the expression f cos represents a denominate number: the projection of the vector f on the vector v . in my opinion, the standard definition of the scalar product of vectors is not free from objection. the objection is that the standard definition is contrary to the formal-logical laws. really, the coincidence (connection) of initial points of vectors and the formation of the projections imply that the dimension of length (i.e., the qualitative determinacy) of the vector v is identical to the dimension of length (i.e., the qualitative determinacy) of the vector f : mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (qualitative determinacy of the vector v ) = (qualitative determinacy of the vector f ). in general case, however, the dimensions of vector lengths are different. therefore, these vectors cannot have a common point, and the multiplication can not be performed (i.e. the multiplication has no sense). this fact is expressed formal-logical law of absence of contradiction: (qualitative determinacy of the vectorv ) (qualitative determinacy of the vector f ). consequently, the mathematical operation of scalar product of two vectors represents a formal-logical error: a violation of the law of absence of contradiction. 4. as is known, the cross-product of two vectors v and f is defined as follows: (a) one brings the initial points of vectors in coincidence with each other (i.e., the initial points are connected); (b) one postulates the relation h v f h v f sin where the cross between the symbols of vectors denotes the operation of vector multiplication of vectors, is angle between the vectors, h is vector which is normal to the plane formed by the vectors v and f ; h is unit vector which is normal to the plane. under the established agreement, the direction of vectors h and h is determined by the “right-hand screw rule”. in my opinion, the standard definition of the cross-product of vectors is not free from objection. the objection is that the standard definition is contrary to the formal-logical laws. really, the coincidence of the initial points of the three vectors means that the dimensions of lengths (i.e., the qualitative determinacy) of the vectors v , f , and h are identical: (qualitative determination of the vector v ) = (qualitative determination of the vector f ) = (qualitative determination of the vector h ). in general case, however, the dimensions of the lengths of the vectors are different. therefore, these vectors cannot have a common point, and the operation of vector multiplication cannot be performed (i.e., the operation of multiplication has no sense). this fact is expressed formal-logical law of absence of contradiction: (qualitative determinacy of the vectorv ) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (qualitative determinacy of the vector f ) (qualitative determinacy of the vector h ). consequently, the mathematical operation of the cross-product of vectors is a formal-logical error: a violation of the law of absence of contradiction. discussion 1. as is known, the confidence in the scientific method of research and in rational thinking replaced all other ways of cognition in the 20th century. rational thinking represents the greatest achievement of mankind. rationalization of thinking and of science is dialectical imperative of our time. the development of rational thinking in the 21st century leads to critical analysis, reconsideration, and rationalization of the generally accepted theories created by the classics of science (for example, n. bohr, e. schrödinger, w. heisenberg, a. einstein, i. newton, g. leibniz, l. euler, j. lagrange, a. cauchy, w.r. hamilton, j.w. gibbs, o. heaviside, etc.). rationalization and critical analysis of science are two side pieces (component factors) in progress of science. critical analysis and rationalization of theories are based on formal-logical analysis of scientific concepts, of the completeness of concepts, of the completeness of a system of concepts because “only the completeness leads to clarity” (confucius). recently, independent researchers give attention to critical analysis of theoretical physics, mathematics, biology, etc. (see, for example, www.gsjournal.net). in the process of critical analysis and of interpretation of scientific theories, “...we can hardly rely on any of the old principles even if they are very common. the only mandatory requirement is the absence of logical contradictions.” (n. bohr). logical consistency of theories is achieved with use of the formal-logical laws. and a natural-scientific interpretation of theories is based on the use of rational dialectics. the system of universal (general-scientific) concepts and laws – i.e., science of the general laws of development of the nature, human society, and correct thinking – is the unity of formal logic and rational dialectics. this unity is not only correct methodological basis of science but also the correct methodological basis for a critical analysis of theories. 2. the origin of vector calculus is closely related to the needs of mechanics and physics: the idea of motion, the concepts of process, velocity, acceleration, displacement, force, and vector were introduced into mathematics in the 17-18th centuries. the modern meaning of the word “vector” represents generalization of its previous (out-of-date) meaning in astronomy, where, in 18th century, a vector is called an imaginary straight line segment connecting the planet to the center (focus) of the motion. at present, vector calculus is a branch of mathematics in which one studies the properties of operations on vectors. but the mathematical formalism does not contain motion, mathematical process. a mathematical process is carried out only in computers. (this is why continual mathematics must be replaced by discrete mathematics – computer mathematics). in specific scientific problem, one considers the quantities of the various natures. these quantities have different dimensions: length, area, volume, weight, temperature, speed, strength, etc.). if one selects a (define, explicit, appointed) determined unit, then each value of the quantity must be expressed by denominate number. but mathematics does not consider the specific quantities: the mathematical propositions and laws are formulated, abstracting from the specific nature of the quantities, taking into consideration only their mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset numerical values. in line with this, mathematics considers the quantity in general, the vector in general, and so on, neglecting the natural-scientific meaning of the quantity. abstract mathematical propositions, theories, and models cannot be tested and used in the natural sciences. from the point of view of formal logic and of rational dialectics, in order to test and use mathematical propositions, theories, and models in practice, it is necessary to define the natural-scientific (practical) meaning of mathematical concepts (objects) and relations, i.e., to consider not a “quantity in general”, a “number in general”, “vector in general”, but to consider the nature (i.e., dimensions) of quantities (length, area, volume, weight, temperature, speed, acceleration, displacement, force, etc.). from this point of view, the standard vector calculus does not have a natural-scientific meaning because the standard vector calculus is based on the concept of “vector in general”. clarification of naturalscientific meaning of concept of “vector” and a logical analysis of operations on the “physical vectors” show that the standard propositions of vector calculus, relating to the “physical vectors”, are contrary to formal logic. 3. there are two opinions about the existence of logical errors in generally accepted theories (for example, in physics and mathematics). the first opinion is that, although a theory (for example, the special theory of relativity) contains logical errors, “it works well” (gerard’t hooft). the second opinion is that the system of four fundamental formal-logical laws is incomplete and insufficient for a panchreston (i.e., for complete explanation) and mathematical description of reality. in essence, these opinions are identical. however, in my opinion, these views are not free from objection. the objection is as follows. if one will discover additional formal logic laws, then the complete system of laws should not be contradictory: the four basic laws will retain its place and importance in a new, complete system (in other words, the four basic laws will not be refuted). in this case, the theories that are erroneous in “incomplete” logical system will also be erroneous in the “complete” logical system. and the theories that contain logical errors are false in essence. but the following questions will always remain open: why devices that are based on false scientific theories (ideas) work? why do the false scientific theories contribute to the development of mankind? where is the limit of development based on false theories? what is the danger of development based on false theories? what are the essence and predestination of development? conclusion thus, the formal-logical and dialectical analysis of the foundations of vector calculus leads to the following main results: the standard vector calculus is incorrect theory because a. it is not based on the correct methodological basis: the unity of formal logic and of rational dialectics; b. it does not contain the correct definitions of concepts of “movement”, “direction”, and “vector”; c. it does not take into consideration the dimensions of physical quantities (i.e., number names, denominate numbers, concrete numbers), characterizing the concept of “physical vector”, and, therefore, it has no natural-scientific meaning; d. operations on “physical vectors” and the theoretical propositions of the standard vector calculus, relating to the “physical vectors”, are contrary to formal logic. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references t. apostol. calculus, vol. 1: one-variable calculus with an introduction to linear algebra. john wiley and sons. isbn 978-0-471-00005-1, (1967). t. apostol. calculus, vol. 2: multi-variable calculus and linear algebra with applications. john wiley and sons. isbn 978-0-471-00007-5, (1969). kiyosi ito. encyclopedic dictionary of mathematics (2nd ed.), mit press, isbn 978-0262-59020-4, (1993). a.b. ivanov. "vector, geometric", in hazewinkel, michiel, encyclopedia of mathematics, springer, isbn 978-1-55608-010-4, (2001). d. pedoe. geometry: a comprehensive course. dover. isbn 0-486-65812-0, (1988). [6] r. aris. vectors, tensors and the basic equations of fluid mechanics. dover. isbn 9780-486-66110-0, (1990). r. feynman, r. leighton, and m. sands. "chapter 11". the feynman lectures on physics, volume i (2nd ed ed.). addison wesley. isbn 978-0-8053-9046-9, (2005). mechanics. berkeley physics course. v. 1. mcgraw-hill book company, (1964). t.z. kalanov. the critical analysis of the foundations of theoretical physics.crisis in theoretical physics: the problem of scientific truth. lap lambert academic publishing. isbn 978-3-8433-6367-9, (2010). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sustainable groundwater management in the karfiguéla alluvial plain: a case study from burkina faso ouédraogo, salif jean-baptiste, traoré, salimata awa and zongo, abdoulaye de l’assainissement du centre-nord, kaya, burkina faso abstract: groundwater is an important source of water for irrigation and drinking in burkina faso. however, the demand for groundwater is increasing due to population growth and climate change. this study investigated the exploitation rate and sustainability of groundwater resources in the alluvial aquifer of karfiguéla. the results showed that the aquifer has a high potential for irrigation, but it is already being exploited at a high rate. this could lead to groundwater depletion in the future. the study recommends that the government of burkina faso take steps to manage groundwater resources sustainably, such as by introducing water pricing and regulations on groundwater abstraction. keywords: groundwater resources, alluvial aquifer, karfiguéla, burkina faso, irrigation, sustainability, water management 1. introduction located in west africa, burkina faso is a landlocked and sahelian country. it covers an area of 274000 square kilometers. its population was estimated in 2010 at 15,370,000 with an annual growth rate of 3.1% (insd, 2006). the economy of burkina faso is mainly based on the primary sector, which provides nearly 80% of the country's exportrelated revenues, employs about 86% of the active population and contributes 40% of the gross domestic product, of which 30.7% represents the agriculture sub-sector. despite its relative importance for the economy, agriculture is facing the effects of the climate change which cause large fluctuations in agricultural production from year to year. this is why successive governments in burkina faso have taken strong action in favor of the irrigation sector. in fact, irrigation appears as one of the alternatives to minimize the influence of the major limiting climatic factors of traditional rainfed agriculture through additional production in dry season and securing winter production with supplemental irrigation. in burkina faso, uncertainties about the beginning and end of seasons, the increase in the number and duration of dry pockets duringwet seasons, the scarcity or seasonality of surface waters are factors contributing to the pressure on groundwater resources (n’go et al., 2005). indeed, groundwater has been considered as less vulnerable to drought (taylor et al., 2009). access to groundwater is conditioned by the drilling wells or boreholes of good quality, able of lasting over time. these boreholes should be located in aquifers with significant storage and / or recharge (parry et al., 2007). outside, these conditions are often poorly assured because of the complexity of the geology of burkina faso consisting of 85% of basement formation (savadogo, 1984). this situation accentuates the pressure on easily accessible alluvial aquifers whose hydrogeological characteristics are better known. the alluvial plain of karfiguéla, located in the cascades region, is an area with strong aquifer potential and therefore suitable for the practice of irrigated agriculture during dry season. however, the establishment of a sustainable management of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset groundwater resources in the alluvial plain of karfiguéla will require the estimation of its potentialities to satisfy populations’ long-term needs. it is within this framework that this study was initiated. it aims to determine the exploitation rate and sustainability of groundwater resources of the alluvial aquifer of karfiguela. 2. study area an alluvial plain is a relatively flat surface, located at the bottom of a valley, consists of alluvium (pebbles, gravel, sand, clay, silt...) and comparable to the flood zone of a stream (sauret, 2013) which generally flows on its alluvium (fine or coarse grains alternately deposited or taken up by the current) covering the bedrock. the sides of the stream of an alluvial plain are bordered by natural plants called riverines. the extent of this vegetation is variable because it can be limited to a narrow tree-line running along the channel of the stream or it can be a real forest, rich in terms of floristic diversity, which can extend over several tens or even hundreds of meters on both sides of the stream channel. the alluvial plain of karfiguéla is located in the comoé province in southwest of burkina faso between longitudes 4°50'0''w and 4°42'0'' w and latitudes 10°44'0 n and 10°28'0"n (figure 1). it covers an area of 46496 km² and is 28 km long. in addition, the alluvial plain of karfiguela houses the localities of karfiguela, tengrela, nafona, lemouroudougou, kribina-lena, tiekuna, niankar, bounouna, kossara, diarabakoko, sitiena and banfora. figure 1: location of the karfiguéla plain in burkina faso, showing the extent, geology and locations of the river, observation wells, villages. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in the alluvial plain of karfiguela, the mean annual rainfall of the last thirty years is 1034 mm. daily temperatures vary from 17° to 36° c (gire 2001). the air relative humidity is variable during the dry season (20% to 80%) while during the rainy season it can reach an average of 94.04%. four types ofsoils are generally encountered in the comoé province: • kaolinitic soils, ocher red tropical ferruginous type, which ensure good drainage; • brown montmorillonite soils with imperfect drainage; sandy-clay soils that provide medium drainage; hydromorphic soils flooded in the wet season. in the karfiguela plain, soils are generally deep and are of tropical ferruginous type (padi, 2014) with a claysilty texture at the top. the soil diversity of the area is undoubtedly a huge potential for agricultural activity. most of these soils are light and sensitive to erosion, which is accelerated by anthropogenic action (extensive production systems, excessive cutting of firewood and anarchic land occupation). the floodplain is mostly occupied by areas dedicated to agriculture. the predominant crop in the winter season is rice. vegetable crops such as cabbage, cucumber, eggplant, chilli and crops such as maize, sorghum and groundnuts are also highly developed in the karfiguela plain during the dry season. geologically, the following formations can be listed: • a tonalite set consisting of granodiorite, tonalite and quartz diorite; • the formation of kawara-sindou sandstone (gks) formed by coarse conglomerate sands. with a thickness ranging from 60 to 350 meters, it overlays on the lower sandstones; • formation of lower sandstone with a thickness ranging from 50 to 300 meters. these lower sandstones are from top to bottom: arkosic fine red sandstones, fine quartzite sandstones, pink schistose sandstones. (hugot, 2002); • a group of schists and volcano-sediments such as pelites, sandstone shales, gray-black gloss schists, tuffaceousschists and rare quartzite horizons. (ouedraogo, 2006). in addition, all these terrains are covered by late loose formations that support crop-friendly soils. these are recent alluvial sediments (in the valleys) or old (on the "plateau") as well as colluvial deposits at the base of the reliefs. concerning the hydrogeology, the alluvial plain of karfiguela comprises two main entities: the sedimentary zones the sedimentary zone consists of a thick series of rocks that contains several aquifers. it is an ancient sedimentary basin, mostly sandy. some aquifers provide very high flows of the order of several tens of cubic meters per hour (gire, 2001). the basement rocks the crystalline basement zone is predominantly granitic with schists, green rocks and dolerites. the exploitable discharges are modest. water resources are either in the weathering zone or in fractured rock (gire, 2001). in addition, hydrogeological studies carried out by the valorization of water resources program of south-west burkina faso (gombert, 1998) show that the distribution of aquifer reserves is very uneven. indeed, the sedimentary zone that covers 20% of the basin contains more than half of the aquifer reserves. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. materials and methods the rate of exploitation of an aquifer, defined as the ratio between the annual volume of extracted water and the volume of water annually renewed by rainfall recharge (equation 1), is frequently used as quantitative indicator of the degree of exploitation of the groundwater resource (orban et al., 2006).this indicator suggests that the sustainable use of the groundwater resource is not to exceed its annual renewal rate; neglecting the fact that groundwater provides many other essential uses, such as the base flow of stream during dry season or the supply of springs. the exploitation of the karfiguela aquifer is mainly intended for agricultural purposes. these operations are done with various water extraction ways (pedal pumps, motor pump, and watering cans). referring to the above definition of the exploitability rate, we will first estimate the volumes of water extraction from the plain and secondly we will estimate the volume of water that recharges the plain. equation 1 where vp (m3) the annual volume of water extracted from the plain, r (m3) the annual recharge. 3.1. estimation of water extraction the method used for water extraction estimation is based on the sum of the volumes of water pumped and extracted manually by farmers in the alluvial plain during the dry season from october to may. the water extraction ways are motor pumps, pedal pumps and watering cans. the implementation of this method of estimating the volumes extracted required field surveys. these surveys covered the number of motor pumps, pedal pumps and watering cans as well as their respective discharge, also taking into account irrigation schedules for each speculation. two major assumptions are made for the estimation of the volumes of water extracted. these include: • the drought period extends over a period of 8 months, from october to may, allowing two off-season agricultural campaigns to be conducted. • in the case of farms with a variable irrigation schedule (due to the plurality of crops), the maximum duration (in hours) of daily irrigation as well as the maximum of days of irrigation are considered for calculations. 3.2 recharge and groundwater storage change estimation for the estimation of groundwater recharge and groundwater storage change, we used thornthwaite and water table fluctuation methods, respectively. 3.2.1 recharge estimation thornthwaite's approach uses the water balance at the catchment scale. it is based on the assumption that for a given time interval, the total inflow of water into a catchment is equal to the total of water outflows summed by the positive or negative water stock change. this balance can be written in the form of an equation involving various parameters: δ ……………………………………………………………equation 2 where p(mm) is rainfall, e(mm) potential evapotranspiration, i(mm) infiltration that recharges the aquifer, r(mm) is runoff and δs is soil water stock change. the equation 2 can be rewritten involving the easily usable reserve (rfu) of soil (equation 3). …………………………………………equation 3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset where for a given month i, rfui-1(mm) is easily usable reserve of the previous month, pi(mm) is precipitation, etoi(mm) is potential evapotranspiration, rfui(mm) is easily usable reserve, ii(mm) is water infiltrated (recharge), ri(mm) is runoff. the computing of this equation allows us, on the one hand, to find the actual evapotranspiration values for each month. on the other hand, it allows us to find the annual value of the effective rainfall from which the part of runoff must be deducted to find the infiltration in the alluvial aquifer according to the equation 4: ……………………………………………………… equation 4 where i(mm) is water infiltrated (recharge) annually and r(mm) is annual runoff. the portion of runoff can be determined from the computation of runoff coefficient (cr) formula which is the ratio of the rainfall participating in the runoff to the actual rainfall recorded at the ground (equation 5): …………………………………………………….equation 5 where cr (%) is runoff coefficient, ler(mm) is rainfall participating in runoff, lep is rainfall recorded at the ground. the computation of the runoff coefficient for a given period involves the decomposition of the flood hydrograph plotted from the data collected by the gauging stations in the study area. the runoff coefficient of the alluvial aquifer of karfiguéla is estimated at 9.830% (sankande, 2012).the average monthly rainfall and temperature data from 1981 to 2014 were used to calculate the various parameters. 3.2.2 estimation of groundwater storage change various methods in aquifer recharge estimation exist. most of them are tributary to recharge mechanism, climate conditions and estimation hypothesis. the wtf method among others is seen to be one of the most used methods (healy et al., 2002) for its independence from climate conditions as stated scanlon et al. (scanlon et al., 2002) and the recharge mechanisms. the method’s popularity comes from its straightforward use and general availability of water table data for recharge estimation (obuobie, 2012). wtf method is based on hypothesis that any water table rise in unconfined aquifer is due to recharge (cai and ofterdinger; 2016). the employed methodology is based on applying the wtf method in conjunction with the groundwater budget method developed by marechal et al. (2006). the wtf method allows estimating change in groundwater storage based on water level fluctuation (equation 6). δs=sy*δh…………………………………………………………………….equation 6 where δs is change in groundwater storage; sy is specific yield or the quantity of water drains from the aquifer by the gravity force; δh is water level fluctuation. the wtf δh is estimated from hydraulic head measurements from piezometers of the site which are not influenced by water abstractions from pumping boreholes. daily monitoring from 2013 to 2015 of piezometers taping the aquifer provided data for δh determination. the specific yield sy of the alluvial aquifer of karfiguela was determined by pumping tests (long-term tests). the average value of sy estimated in the alluvial plain of karfiguela is 0.842%. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3.3 estimation of the sustainability of the aquifer exploitation the sustainability of the groundwater resource in the alluvial aquifer of karfiguela depends on many internal and external factors. a balance of inputs and outputs (δq) in this aquifer (equation 7), related to the volume of the exploitable resource, could be used to estimate the number of years of exploitation (equation 8): δ ………………………………………equation 7 where vr (m3) is recharge; vrip (m 3) aquifer water inflow from the stream to the aquifer; vapp (m 3) is water inflow from the deep aquifer; vp (m3) is water extracted; vpri (m 3)is water outflow from the aquifer to the stream; ………………………………………………………………………….equation 8 where x is number of years of future exploitation and vrese (m3) is volume of the exploitable water resource. 4. results and discussion 4.1estimation of water extraction the volumes of withdrawals according different water extraction ways in the alluvial plain are recorded in table 1. the values show that almost all the groundwater withdrawals in the aquifers are carried out by motor pumps. in addition, these groundwater withdrawals concern a part of the localities hosted in the alluvial plain, namely the villages of karfiguéla, kitobama, lemouroudougou and siniena. however, farmers in the villages of karfiguéla and lemouroudougou extract more groundwater while those in the villages of siniena and kitobama have lower percentages of exploitation. table 1. volume of water withdrawals according to extraction ways in the alluvial plain of karfiguéla withdrawalway volume (m3) motorpumps 199680.00 pedalpumps 0.00 wateringcans 152.00 total 199832.00 4.2 estimation of groundwaterrecharge the table 2 shows the effective annual rainfall. the annual runoff obtained from the total annual rainfall recorded at the ground and runoff coefficient is estimated at 101.8 mm/ year. this value subtracted from the effective annual rainfall (i + r) allows us to estimate an annual groundwater recharge of 40.5 mm / year. therefore, considering the surface of the alluvial plain (46 496 000 m²), the volume of water having recharged the aquifer is estimated at 1 884 891.950 m3. table 2: values of effective rainfall computed using thornthwaite water balance method applied to the alluvial plain of karfiguéla. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset month etp (mm) p (mm) rfu (mm) etr (mm) i+r (mm) january 193.299 1.155 0.000 1.155 0.000 february 180.537 1.797 0.000 1.797 0.000 march 197.079 16.770 0.000 16.770 0.000 april 187.203 60.670 0.000 60.670 0.000 may 178.559 101.888 0.000 101.888 0.000 june 148.607 145.530 0.000 145.530 0.000 july 134.796 184.233 49.438 134.796 0.000 august 126.758 265.458 100.000 126.758 88.137 september 132.314 186.439 100.000 132.314 54.126 october 159.478 62.236 2.758 159.478 0.000 november 168.056 7.194 0.000 9.952 0.000 december 183.467 1.464 0.000 1.464 0.000 total (mm/year) 1034.833 142.263 4.3 estimation of groundwater storage change the use of the water table fluctuation method in the alluvial plain of karfiguela shows that the interannual mean of the positive piezometric head variations (δh) is equal to 4804.7 mm. the water storage change is then estimated at 1881039.98 m3.the recharge value estimated using thornthwaite method and the groundwater storage change value estimated using water table fluctuation method are substantially identical. in other words, the annual recharge is approximately identical to the annual volume of renewable water. 4.4 estimation of the exploitation rate of alluvial plain of karfiguéla the exploitation rate of the alluvial aquifer of karfiguela is estimated at 10.60%. this rate indicates a low use of groundwater. in fact, among the 212 farmers in the plain, only 12 farmers use groundwater for irrigation. these situations are related to the easy access to surface water in the plain. indeed, a supply from the comoériver serves irrigated perimeters from surface water which remains sufficiently abundant despite the multitude of operators and climatic hazards. moreover, the exploitation of groundwater in the plain would probably be limited red by the relatively high realization costs of wells and boreholes. 4.5 estimation of the exploitation sustainability of the alluvial plain in the alluvial aquifer of karfiguéla groundwater abstractions are minimal compared to the annual recharge. this annual recharge largely balance the amount of water with drown by farmers and the sustainability of the water mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset resource does not seem to be at risk. however, the change in the rate of exploitation by intensification of water abstraction caused by the arrival of new farmers should be regulated by local sensitization actions and field visits to better manage the groundwater resource. environmental protection can also contribute to sustainable management by preserving the vegetation cover, which plays an important role in runoff and water infiltration. in addition, further studies on this aquifer, including the aquifer/river exchanges, would make it possible to understand the contribution of surface and groundwater on order to support a sustainable management with easy access. 5. conclusion the study of exploitation rate and sustainability of the alluvial aquifer of karfiguéla revealed that the annual recharge is substantially identical to the variation of the groundwater stock. this recharge is around 1885000 m3. water abstracted from the aquifer is much lower than the volume of water renewed, about 10%. therefore, the alluvial aquifer of karfiguéla has sufficient recharge to compensate the withdrawals, so the sustainability of its exploitation does not seem to be threatened. the complete characterization of the studied aquifer is an asset in the search for its exploitation rate and facilitates the deductions relating to its durability. the work carried out during this study shows that sustainable management of the groundwater resource of the alluvial aquifer of karfiguéla requires the union of stakeholders in their exploitation, namely farmers, policy makers and development partners. references cai, z., ofterdinger, u. (2016) analysis of groundwater-level response to rainfall and estimation of annual recharge in fractured hard rock aquifers, nw ireland. journal of hydrology, 535, 71–84. gire burkina (2001). etat des lieux des ressources en eau du burkina faso et de leur cadre de gestion. ministère de l’environnement et de l’eau. burkina faso rapport healy, r.w. and cook, p.g. (2002) usinggroundwaterlevels to estimate recharge. hydrogeology journal, 10 (1), 91–109. hugot, g. (2002). à la recherche du gondwana perdu : aux origines du monde hydrogéologie. insd. (2006) recensement general de la population et de l’habitation de 2006. ministère de l’économie et des finances / bureau central du recensement. ouagadougou (burkina faso). rapport maréchal, j.c., dewandel, b., ahmed, s., galeazzi, l., and zaidi, f. k. (2006). combined estimation of specific yield and natural recharge in a semi-arid groundwater basin with irrigated agriculture. journal of hydrology, 329 (1), 281-293. n’go, y.a., goné, d.l., savane, i. and goblé m.m. (2005) potentialités en eaux souterraines des aquifères fissurés de la région d’agboville (sud ouest de la côte d’ivoire): caractérisation hydroclimatique et physique. afrique science, 1 (1), 127–144. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset obuobie, e., bernd, d., william, a. and sampson, a. (2012) groundwater level monitoring and recharge estimation in the white volta river basin of ghana . journal of african earth sciences, 71, 80–86. orban, p., ruthy, i. &brouyere, s. (2006). etat quantitatif et qualitatif des eaux souterraines en région wallonne : dossier scientifique réalisé dans le cadre de l’élaboration du rapport analytique 2006-2007 sur l’état de l’environnement wallon. ulg-fsaargenco-geo3 ouédraogo, c. (2006), synthèse géologique de la region ouest du burkina faso ; octobre padi -bf 101 (2014), synthèse des mesures piézométriques et hydrométriques réalisées dans la plaine alluviale de karfiguéla, rapport. parry, m.l., canziani, o.f., palutikof, j.p, vander linden, p.j and hanson, c.e., (2007). contribution of working groupii to the fourth assessment report of the intergovernmental panel on climate change, cambridge university press, cambridge, uk. philippe gombert (1998), synthèse sur la géologie et l'hydrogéologie de la série sédimentaire du sud-ouest du burkina faso, rapport. sauret, e. (2013), étude des potentialités hydrogéologiques de la plaine alluviale en relation avec les eaux souterraines et de surface dans un contexte d'agriculture irriguée (burkina faso) thèse de doctorat, université de liège. savadogo, a. n. (1984) géologie et hydrogéologie du socle cristallin de haute-volta. etude régionale du bassin versant de la sissili. thèse de doctorat d'état, université scientifique et médicale de grenoble, 340 p scanlon, b.r., healy, r.w. and cook, p.g. (2002) choosing appropriate techniques for quantifying groundwater recharge. hydrogeology journal, 10, 18–39. taylor, r.g., kouassi, a.d. and tindimugaya, c. (2009). groundwater and climate in africaa review. hydrological sciences journal, 54 (4), 655–664. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset industrial palm oil milling machines starting torque effect of removing compensating winding using universal machine chizindu stanley esobinenwu1 and lamidi salihu owuda2 1&2 department of electrical/electronic engineering, university of port harcourt, rivers state, nigeria. email: chizindu.esobinenwu@uniport.edu.ng & owuda@yahoo.com doi: https://doi.org/10.5281/zenodo.10814648 abstract: industrial palm oil milling machines starting torque effect of removing compensating winding using universal machine is presented. the palm oil milling plant machine is the equipment use for processing of raw material reception, sterilizing, threshing, digesting, pressing, clarifying, drying and the output product is palm oil. compensation machine windings are a winding in the field pole face plate that carries armature current to reduce stator field distortion. its purpose is to reduce brush arcing and erosion in machine that operates with weak fields, variable heavy loads and reversing operation. uncompensated windings of industrial palm oil milling machines have received negative threat in oil production due to this phenomenon. the series reactance was reduced by fewer turn of heavier wire gauges and is impracticable to eliminate reactance voltage drop so as not to eliminate magnetic field. the reactance voltage drop was completely eliminated by the uses of compensating windings immediately it was connected in series with armature of mill universal machine, and arranged so that the ampere-turns of the compensating winding opposes and neutralizes the ampere-turns of the armature. the compensating winding displaced 90 electrical degrees from the field winding and the mechanical displacement 45 degrees. the commutation also improves considerably universal machines operates both on alternating current and on direct current source. when coupled to electro-dynamometer, the machine current and the torque developed were recorded as i=3.7amps dc and torque =16ibf.in. the industrial palm oil milling universal machine for uncompensated for ac operation the current and speed was recorded as current (i) = 2.4aac and ac speed = 230rev/min. and more sparking at the brushes and for uncompensated for dc operation the current and speed was recorded as current (i) = 2.5aac and ac speed = 2680rev/min. the industrial palm oil universal machine was loaded up to 9ibf.in. the industrial palm oil milling universal machine for inductive compensation operation the current, speed and torque was recorded as current (i) = 2.4aac, ac speed = 1430rev/min and ac torque = 9ibf.in. industrial palm oil milling universal machine stalled as soon as the short was removed. the full power cannot develop when it is uncompensated. inductive compensation for dc operation, the current, speed and torque was recorded as current (i) = 4.1adc, dc speed = 2400rev/min and ac torque = 9ibf.in. and there was no changed when the short was removed. this recommended for machines designers and operators of industries of palm oil milling, fans and blowers, hair dryers, electric shavers, electric heir clippers, can openers, sewing machines, vibrators, coffee grinders, power screwdrivers, nut drivers, sabre saws, and hedge clippers. keywords: armature, milling, compensating, universal, commutation, brush sparking, erosion, and neutralizes. mailto:topacademicjournals@gmail.com mailto:chizindu.esobinenwu@uniport.edu.ng mailto:owuda@yahoo.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1.0 introduction industrial palm oil milling machines starting torque effect of removing compensating winding using universal machine is presented. the palm oil milling plant machine is an equipment use for processing of raw material reception, sterilizing, threshing, digesting, pressing, clarifying, drying and the output product is palm oil. [1, 4, 5] compensation machine windings are winding in the field pole face plate that carries armature current to reduce stator field distortion. [3, 7, 8] it reduce brush arcing and erosion in machine that are operates with weak fields, variable heavy loads and reversing operations. uncompensated windings of industrial palm oil milling machines have received negative threat in oil production. the starting torque of universal machine is determined by the current that flows through the armature and field windings. [3, 10] the inductive reactance of these windings, the alternating current (ac) starting current is always less than that of direct current (dc) starting current. [4, 9]. thus, the starting torque on ac power will be lower than that of starting torque on dc power. the compensating winding has a very great important role to play of reducing the overall reactance of the machine. the compensating windings also has the ability of opposing armature reaction, thereby improves commutation. [2, 6, 8]. the universal machine that is not compensated has the ability to lose most of its power and worsen brushes sparking. [5, 6, 7] 2.0 laboratory investigation on industrial palm oil milling universal machines a laboratory experiment was carried out in the standard research uniport laboratory to investigate the industrial palm oil milling machines starting torque effect of removing compensating winding using universal machine. the materials, instruments and components used are: (1) universal machine, (2) power supply, (3) electrodynamometer, (4) ac metering current module (2.5a, -8.0a), (5) ac metering voltmeter module (100v250v), (6) dc metering volt-amps (200v, 2.5-5a), (7) hand tachometer, (8) connecting leads and (9) timing belt. the course of carrying out the investigation on industrial palm oil milling universal machines starting torque effect of removing compensating winding using universal machine. a high-level peculation was observed at every laboratory experiment as high voltage was present in the laboratory. no connection was made with power ‘on’ at every experimental connection, and power must be switch ‘off’ after connecting each individual experimental connection. 3.0 industrial palm oil milling universal machines starting torque for dc operation using the materials, instruments and components as stated above, the industrial palm oil milling universal machine connection for dc operation is shown in figure1. the power was turn ‘on’ after connection and it was adjusted to 30v using the control knob on the power supply. at the 30v power supply the line current was less than 1.0ampere and the compensating winding was producing flux in the same direction as the armature thereby increasing the inductance and reactance. it was also observed that the armature revolves and the brushes were mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset not at exactly neutral position. as a result of this, an interchanged of the lead to armature winding was made and the system normalized and the line current was measured and recorded as 3.5a ac. 𝐈𝟏 figure1: circuit diagram of industrial palm oil milling universal machine for dc operation the electro-dynamometer was coupled to the industrial palm oil milling universal machine with timing belt. the input terminal of the electro-dynamometer was connected to 220 vac terminal 1 and neutral (n). the electro-dynamometer was adjusted to its full clockwise position to provide a maximum starting load for industrial palm oil milling universal machine and brushes were set to their neutral position. the machine was turned ‘on’ and an adjustment was made as indicated on the voltmeter to 30v supply to industrial palm oil milling universal machine windings. the industrial palm oil milling universal machine current and the torque developed were recorded as current (i) = 3.7amps dc and torque =16ibf.in. the voltage was returned to zero and the power was turn ‘off. 4.0 industrial palm oil milling universal machine for ac operation using the materials, instruments and components, the industrial palm oil milling universal machine connection was reconnected for ac operation is shown in figure2. the power was turn ‘on’ after connection and it was adjusted to 30v using the control knob on the power supply. the industrial palm oil milling universal machine current and the torque developed were recorded as current (i) = 1.4amps ac and torque =1.6ibf.in. the voltage was returned to zero and the power was turn ‘off. it was observed from the result that the inductive reactance of the armature and field windings limits field current during ac operation. this reduced the ac starting torque drastically below the starting torque. palm oil mill universal machine palm oil mill electrodynamometer m v a 5 4 3 0 – 220-vac 0 -2 2 0 v d c 0 – 250vdc voltmeter 0 – 2.5adc ammeter voltmeter control knob w 2 1 6 + _ + _ l n l n mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 𝐈𝟏 figure2: circuit diagram of industrial palm oil milling universal machine for ac operation 5.0 industrial palm oil milling universal machine for uncompensated for ac operation using the materials, instruments and components, the industrial palm oil milling universal machine connection was reconnected for uncompensated windings for ac operation by eliminating the compensating coil winding as shown in figure 3. the power was turn ‘on’ after connection and it was adjusted to 220vac using the control knob on the power supply and the electro-dynamometer to 3ibf.in of the torque. the industrial palm oil milling universal machine for uncompensated operation the current and speed was recorded as current (i) = 2.4aac and ac speed = 230rev/min. the current is almost the same but the speed is much slower. without the compensated windings for the industrial palm oil milling universal machine, the universal machine produces less power and more sparking at the brushes palm oil mill universal machine palm oil mill electrodynamometer m v a 5 4 3 0 – 220-vac 0 -2 2 0 v a c 0 – 250vac voltmeter 0 – 2.5aac ammeter voltmeter control knob w 2 1 6 + _ + _ l n l n mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 𝐈𝟏 figure3: circuit diagram of industrial palm oil milling universal machine for uncompensated for ac operation. 6.0 industrial palm oil milling universal machine for uncompensated for dc operation using the materials, instruments and components, the industrial palm oil milling universal machine connection was reconnected for uncompensated windings for dc operation by eliminating the compensating coil winding as shown in figure 4. the procedure as before, the industrial palm oil milling universal machine for uncompensated operation the current and speed was recorded as current (i) = 2.5aac and ac speed = 2680rev/min. palm oil mill universal machine palm oil mill electrodynamometer m v a 5 4 3 0 – 220-vac 0 -2 2 0 v a c 0 – 250vac voltmeter 0 – 2.5aac ammeter voltmeter control knob w 2 1 6 + _ + _ l n l n mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 𝐈𝟏 figure4: circuit diagram of industrial palm oil milling universal machine for uncompensated for dc operation. 7.0 mathematical model the three main components of palm oil mill universal machine torque are: reluctance torque, synchronous torque, excitation torque. [3, 4, 7] palm oil milling universal machine torque 𝑇𝑒𝑚 = 1.5 p (𝜆𝑑 𝑖𝑞 𝜆𝑞 𝑖𝑑) (1) palm oil milling universal machine reluctance torque 𝑇𝑟 = 1.5 𝑃 (𝐿𝑑 − 𝐿𝑞)𝑖𝑑𝑖𝑞 (2) palm oil milling universal machine synchronous torque 𝑇𝑠𝑦𝑛 = 1.5 p (𝐿𝑚𝑑 𝑖𝑘𝑑𝑖𝑞 𝐿𝑚𝑞 𝑖𝑘𝑞𝑖𝑞) (3) palm oil milling universal machine excitation torque palm oil mill universal machine palm oil mill electrodynamometer m v a 5 4 3 0 – 220-vac 0 -2 2 0 v d c 0 – 250vdc voltmeter 0 – 2.5dc ammeter voltmeter control knob w 2 1 6 + _ + _ l n l n mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 𝑇𝑒𝑥 = 1.5 p 𝐿𝑚𝑑 𝑖𝑓𝑚𝑖𝑞 (4) where p are pole pairs, assumed the line voltage are balanced, the d-q voltages in terms of the load angle become, 𝑉𝑑 = -v sin 𝛿 (5) 𝑉𝑑 = v cos 𝛿 (6) stator phase current is related to the d-q currents [3, 9]. 𝑖𝑎𝑥 =𝑖𝑞 (7) 𝑖𝑏𝑥= 1 2 𝑖𝑞 1 √3 𝑖𝑑 (8) 𝑖𝑐𝑥 = 1 2 𝑖𝑞 + 1 √3 𝑖𝑑 (9) 8.0 mechanical model the mechanical model of the palm oil mill universal machine which allows the inertia and mechanical load torque to be incorporated, [1, 5, 7] swing equation equations (10-11), �̇� = 𝜔𝑏 𝜔𝑟 (10) 𝜔�̇� = 𝑝 𝑗𝑚 (𝑇𝑒𝑚 𝑇𝐿) (11) 𝐽𝑚 𝑑2𝜃𝑚 𝑑𝑡2 = 𝑇𝑐 𝑇𝐿 (12) decomposing equation (12) into two first order differential equation gives, p𝜃𝑚=m (13) 𝐽𝑚 (p 𝜔m ) = 𝑇𝑐 𝑇𝐿 (14) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset p 𝜔m = 1 𝐽𝑚 (𝑇𝑐 𝑇𝐿) (15) 𝑇𝑒𝑚 + integrator integrator _ δ δ 𝑇𝐿 gain( 𝑝 𝑗𝑚 sum 𝜔𝑏 + sum figure 5: mechanical model block diagram of palm oil mill universal machine control table 1: laboratory investigation results on industrial palm oil milling universal machine for compensated operation. s/no. current(i) va p(watts) speed (r/min) horse power(hp) torque (ibf.in) 1 1.8 226 208 3448 0 0 2 2.2 274 243 2548 0.120 3 3 2.8 246 288 1858 0.175 6 4 3.3 406 323 1388 0.188 9 table2: laboratory investigation results on industrial palm oil milling universal machine for uncompensated operation. s/no. current(i) p(watts) speed (r/min) horse power(hp) torque (ibf.in) 1 1.5 238 4148 0 0 2 1.8 288 3298 0.155 3 3 2.3 358 2598 0.246 6 4 2.7 388 2198 0.313 9 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 3: industrial palm oil milling universal machine parameters in simulation d-axis inductance,𝐿𝑑 1.4mh q-axis inductance, 𝐿𝑞 2.8mh (1.4mh) stator windings 𝑅𝑠 0.6 ω (1.2 ω) induced flux by magnet 0.12wb number of poles, p 2 rated voltage, v 250 v rated frequency, f 50hz combined rotor and load inertia, 𝐽𝑚 0.83kg𝑚2 shaft mechanical torque, 𝑇𝑙 3.2nm source: [3, 5, 6, 7] figure 6: graph of rotor speed against time for varying stator resistance. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 -100 0 100 200 300 400 500 600 time [s] ro to r s pe ed ,  r [r ad s/ se c] 0.2599 0.2050 0.3158 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 7.: graph of motor torque against time for varying stator resistance figure 8: graph of rotor speed against time. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 -200 -150 -100 -50 0 50 100 150 200 time [s] mo tor to rqu e, t m [n m] 0.2599 0.2050 0.3158 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 -200 -100 0 100 200 300 400 time [sec] ro to r s pe ed [r ad s/ se c] mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 9: graph of torque against time figure 10: graph of rotor speed against time 9.0 industrial palm oil milling universal machine for inductive compensation for ac operation. the effect of using inductive compensation while the industrial universal machine is operating on ac. using the materials, instruments and components, the industrial palm oil milling universal machine connection was reconnected for inductive compensation as shown in figure3. the compensating coil was short 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 -40 -20 0 20 40 60 80 100 time, [s] to rq ue , t e, [n m ] te th 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 -50 0 50 100 150 200 250 time [sec] r ot or s pe ed [r ad s/ se c] mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset out by connecting a lead directly across its terminals. the power was turn ‘on’ and adjusted for 120vac. the industrial palm oil universal machine was loaded up to 9ibf.in. the industrial palm oil milling universal machine for inductive compensation operation the current, speed and torque was recorded as current (i) = 2.4aac, ac speed = 1430rev/min and ac torque = 9ibf.in. it was observed that the sparking was the same when the industrial palm oil milling universal machine was conductively compensated. while the machine was on operation, the shorted compensating coil was removed by holding the wire with insulating material as a precaution. the industrial palm oil milling universal machine stalled as soon as the short was removed. the full power cannot develop when it is uncompensated. 10.0 industrial palm oil milling universal machine for inductive compensation for dc operation. using the same procedure, the industrial palm oil milling universal machine for inductive compensation for dc operation the current, speed and torque was recorded as current (i) = 4.1adc, dc speed = 2400rev/min and ac torque = 9ibf.in. it was observed that the dc and ac industrial palm oil milling universal machine for inductive compensation operation does not work at the same level of operation. it was observed that the inductive compensation is effective only when the current is alternating. the performance is the same with compensating winding shorted as when it is open. while on the dc, the industrial palm oil milling universal machine draw more current and there was severe sparking at the brushes. compensation machine windings are a winding in the field pole face plate that carries armature current to reduce stator field distortion it was used to reduce brush arcing and erosion in the palm oil milling machine so that it can operates on weak fields, variable heavy loads and reversing operations. the reactance of the series was reduced by fewer turn of heavier wire gauges. in the series field, it is not practicable to eliminate reactance voltage drop so as not to eliminate magnetic field. the reactance voltage drop was completely eliminated by the uses of compensating windings and this was connected in series with armature of palm oil milling machine and it was so arranged so that the ampere-turns of the compensating winding opposes and neutralizes the ampere-turns of the armature. the compensating winding displaced 90 electrical degrees from the field winding and the mechanical displacement 45 degrees. the commutation also improves considerably universal machines operates both on alternating current and on direct current source. the speeds at which the universal machines operate depend on the designer, though universal machines operate faster on dc than on ac source. it was observed that the dc and ac industrial palm oil milling universal machine for inductive compensation operation does not work at the same level of operation. it was observed that the inductive compensation is effective only when the current is alternating. the performance is the same with compensating winding was shorted as when it is open. while on the dc, the industrial palm oil milling universal machine draw more current and there was severe sparking at the brushes. the compensating windings are necessary to reduce reactance effects of the armature winding. this allows more ac current to be drawn and increase the power output capability and improving commutation. 11.0 conclusion mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the dc and ac industrial palm oil milling universal machine for inductive compensation operation does not work at the same level of operation. the inductive compensation is effective only when the current is alternating. the performance is the same with compensating winding shorted as when it is open. while on the dc, the industrial palm oil milling universal machine draw more current and have severe sparking at the brushes. at the 30v power supply, the line current was less than 1.0ampere and the compensating winding were producing flux in the same direction as the armature thereby increasing the inductance and reactance. the armature revolves and the brushes were not at exactly neutral position. as a result of this, an interchanged of the lead to armature winding was made and the system normalized and the line current was measured and recorded as 3.5a ac. when coupled to electro-dynamometer, the machine current and the torque developed were recorded as i=3.7amps dc and torque =16ibf.in the industrial palm oil milling universal machine for uncompensated for ac operation the current and speed was recorded as current (i) = 2.4aac and ac speed = 230rev/min. without the compensated windings for the industrial palm oil milling universal machine, the universal machine produces less power and more sparking at the brushes. while the industrial palm oil milling universal machine for uncompensated for dc operation the current and speed was recorded as current (i) = 2.5aac and ac speed = 2680rev/min. when the industrial palm oil universal machine was loaded up to 9ibf.in for inductive compensation operation the current, speed and torque was recorded as current (i) = 2.4aac, ac speed = 1430rev/min and ac torque = 9ibf.in. it was observed that the sparking was the same when the industrial palm oil milling universal machine was conductively compensated. while the machine was on operation, the shorted compensating coil was removed by holding the wire with insulating material as a precaution. industrial palm oil milling universal machine stalled as soon as the short was removed. the full power cannot develop when it is uncompensated. while for the industrial palm oil milling universal machine for inductive compensation for dc operation, the current, speed and torque was recorded as current (i) = 4.1adc, dc speed = 2400rev/min and ac torque = 9ibf.in. and there was no changed when the short was removed. this recommended for machines designers and operators of industries of palm oil milling, fans and blowers, hair dryers, electric shavers, electric heir clippers, can openers, sewing machines, vibrators, coffee grinders, power screwdrivers, nut drivers, sabre saws, and hedge clippers. references l, chang “comparison of ac drives for electric vehicles – a report on experts, opinion survey,” ieee aes systems magazing.pp. 7-10. 2019. l.h. hoang, “comparison of field –oriented control and direct torque control for induction motors,” in proc.ieee , industry application conference, vol.2, pp. 12451252.2019 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a. kishore, r.c.prasad, m.b. karen, “matlab/ simulink based dq modeling and dynamic characteristics of three – phase self-exited induction generator” progress in electromagnetic research symposium, cambridge, usa, march, 26-29, pp 312-316, 2016 c. mademlis, j. xypteras, n. margaris, “loss minimization in surface synchronous motor drives”, ieee trans. industrial electronics, vol.47, no. 1, pp. 115122, 2005 o.i. okoro, “matlab simulation of induction machine with saturable leakage, and magnetizing inductance”,botswana journal of technology, vol. 12.no.1, pp.20-28, 2004 o.i. okoro, “transient analysis of a synchronous machine with damper windings”, nejrd, vol.3 no.4. pp 66-69. 2005. p. pillay,.r. krishnan, “modeling, simulation and analysis of machines drives part 11: the brushless dc machines drive,” ieee trans. industry application, vol. 25, no. 2, pp102-105,1989. m.a. rahman, t.a., little, p.k. dash, “computer simulation of the dynamic performance of permanent magnet synchronous motors”ias annual meeting, pp511-514, 1989. m.a. rahman, t.a. little, “dynamic analysis of permanent magnet synchronous motors” ieee trans., vol. 103, no. 6, pp. 12771280, 1984 [m.a. rahman a.m. osheiby, “effect of parameter variations on the performance of permanent magnet motors,” ias annual meeting, pp,787-793, 1984 mailto:topacademicjournals@gmail.com 060910-zpk230020 academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset revolutionizing agriculture: mechanical electronic engineering in machinery integration control deng, xiao-qiang 1college of mechanical and transportation, southwest forestry university, kunming, 650000, yunnan, china abstract: the rapid advancements in science and technology have ushered in a new era of intelligent and automated agricultural production, propelling the fields of control engineering and mechanical electronic engineering toward greater intelligence and automation. this symbiotic relationship between the two fields has led to an ever-increasing demand for control technology. consequently, this article delves into the research and implementation of an integrated intelligent agricultural machinery system. the primary focus is on elucidating the application methodologies of the 3s integration framework, webgis, and related technologies within the realm of intelligent agricultural machinery. the crux of this endeavor revolves around harnessing the power of the 3s (geographic information system, global positioning system, and remote sensing) technology, with the overarching objective of constructing an agricultural machinery service management integration platform under the robust architecture of webgis. furthermore, this research aims to seamlessly incorporate emerging computer concepts like the internet of things, cloud computing, and the b2c e-commerce model into the framework of intelligent agricultural machinery. the integration of these cutting-edge concepts into the 3s technology framework serves as the linchpin of this research. the objective is to maximize their inherent strengths, establish a series of technical framework models, and expedite the development of a resilient and potent intelligent agricultural machinery integration system. keywords: intelligent agriculture, 3s integration framework, webgis architecture, internet of things, cloud computing 1. introduction the development of science and technology has accelerated the intelligent and automatic process of agricultural production, and also made machinery and electronic engineering gradually develop in the direction of intelligence and automation, which makes the demand and demand for control technology constantly increase. there is a complementary relationship between control engineering and mechanical electronic engineering. the development of both can not only promote the rapid development of mechanical electronic engineering, but also provide more possibilities and development directions for it. therefore, this article conducts research on the implementation of intelligent agricultural machinery integration system, focusing on exploring the application methods of 3s integration framework, webgis and other related technologies in intelligent agricultural machinery, with the core of building 3s technology and the goal of building an agricultural machinery service management integration platform under webgis architecture. at the same time, in response to the newly proposed concepts in the computer field such as the internet of things, cloud computing, b2c e-commerce mode, how to apply them in intelligent agricultural machinery and integrate them into the 3s technology framework, in order to mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset better utilize their own advantages, establish a series of technical framework models, and quickly develop a stable and powerful intelligent agricultural machinery integration system. the innovative application of mechanical engineering in agricultural machinery integration is one of the current research hotspots, among which sun wei's goal is to focus on developing an integrated device for self-cleaning air filters of agricultural machinery air conditioning condensers, which can effectively solve the air cooling problem of agricultural machinery condensers caused by poor working conditions. agricultural machinery and air conditioning condensers are prone to blockage by dust, pests, weeds, etc., resulting in poor heat dissipation and frequent malfunctions. to save resources, improve economic efficiency, adapt to agricultural structural adjustment, and improve the technical level of agricultural environmental protection equipment [1]. pimonratanakan sudarat's research adopts quantitative and qualitative research methods. quantitative research was used to investigate the reasons and relations of production of agricultural machinery business [2]. abuselidze george proposed that the current situation requires manufacturers to focus their agricultural machinery activities on long-term profits and business efficiency [3]. tian hongkun believes that in the future, computer vision technology would be combined with intelligent technologies such as deep learning technology, applied to all aspects of agricultural production management based on large-scale datasets, and more widely applied to solve all aspects of agricultural production management. to solve current agricultural problems and better improve the economic, universal, and robust performance of agricultural automation systems, thereby promoting the development of agricultural automation equipment and systems towards a more intelligent direction [4]. however, due to insufficient data sources, the above research is only in the theoretical stage and lacks practical significance. after consulting a large number of literatures, this paper studies and analyzes the internet of things, cloud computing, b2c mode and 3s (integration of gps, rs and gis technology) integration technology, and integrates these technological convergence together, thus finding a basic framework model suitable for intelligent agricultural machinery integrated system [5-6]. based on 3s technology and the software requirements of the system, the design of the system's structural system, functional modules, performance indicators, workflow, and database was ultimately achieved. the system's structural system, functional modules, performance indicators, workflow, and database were selected, and related software development techniques were used to carry out research and development work. 2. design and smart electromechanical systems in agricultural machinery integration 2.1. overall system design from the perspective of the data needs of the intelligent agricultural machinery integration system, the data involved in the system can be divided into three classes for data sharing and services on the intelligent agricultural machinery integration platform; business data includes three categories: agricultural machinery service organization, inter data, business data, and resource data, including basic geographic data, remote sensing images of agricultural machinery, orders, and related information data of different users, providing data support for business systems. the resource data includes information related to data backup, resource management and maintenance, user role permissions, etc., providing data support for business applications [7]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the intelligent agricultural comprehensive management system is built on a network foundation, therefore it uses a browser/server architecture (b/s, browser/server) development method; j2ee with three-tier structure is divided into presentation layer, middle layer, and data service layer; in order to ensure the universality, efficiency, portability, and security of the system, this article selects the java platform for system development and deployment; software system development is carried out through java language and webgis related technologies, and technologies such as the internet of things, cloud computing, and b2c e-commerce mode are introduced in the research and development. 3s technology is used for data collection, management, calculation, analysis, and display to achieve a smart agricultural machinery integration system [8-9]. based on the principles of b/s design mode and j2ee three-tier architecture, and combined with the actual functional requirement of the system, it is divided into three layers: user layer, application layer and data layer, as shown in figure 1. postgresql geoserver web service figure 1. structure diagram of intelligent agricultural machinery integration system from figure 1, it can be seen that the user layer is a place for in machine interaction, where various functional pages of the system can be displayed in different browsers. this article adopts the jquery framework and ajax technology to develop web page interaction functions. with the help of openlayers technology, various map functions of webgis are completed. users can send request instructions to the application layer through http (hyper text transfer protocol) requests in the browser, using the internet's transmission protocol. after the system processes these requests, the required data results are returned to complete the user's operation function. openlayers is a javascript package used to develop webgis clients, with an application layer deployed on a web server, consisting of two parts: the control layer and the business logic layer. the control layer is managed by struts, which ensures interaction between the user layer and the business logic layer. the role of spring can be extended to the entire application layer. it can be accessed through the combination of struts and spring, using java functional code to access data services in the data layer. finally, the application layer searches for data based on user request instructions and returns it to the user layer, allowing users to perform operations. in the data layer, it includes geoserver servers and postgresql databases, as well as some distributed web services and map services. the application layer utilizes access to the geoserver server and postgresql database b rowser model jquery 、 ajax 、 openlayers j2ee three-tier architecture control layer business logic layer browser mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to obtain basic geographic information data and business data. the java functional code in the application layer can directly call the agricultural machinery terminal monitoring data service published by the data center, or use the internet to call the slicing service of published remote sensing images and vector maps, and feedback the data to the user's hands in the application layer. the data layer provides sufficient data support for the entire system's work [10-11]. 2.2. system module design the intelligent agricultural machinery integration system is mainly used by farmers, agricultural machinery service organizations and governments. each user would have different functional requirement, and there would be certain data logical relationships between different users [12-13]. therefore, when designing the system modules, it should design each functional module of the system based on the user's functional requirement and the relationship between them. the intelligent agricultural machinery integration system mainly includes three subsystems, namely the agricultural machinery operation service system, the agricultural machinery operation scheduling and supervision management system, and the agricultural machinery operation auxiliary decisionmaking system. each subsystem is composed of different functional modules [14]. the overall module design of the intelligent agricultural machinery integration system is shown in figure 2: operation service system agricultural machinery operation management system figure 2. intelligent agricultural machinery integrated system the agricultural machinery operation service system mainly includes four modules: homepage, supply information, order management, and job allocation. it provides farmers with functions such as agricultural machinery service organization retrieval, map display operation, order management (adding, deleting, modifying, querying), and assigning agricultural machinery service organizations to orders. the agricultural machinery job scheduling and monitoring management system consists of modules such as homepage, order management, job scheduling, job supervision, job analysis, information management, trajectory intelligent integrated agricultural machinery syste m agricultural machinery agricultural machinery operation scheduling and monitoring auxiliary decision system for mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset point management, etc., enabling users of agricultural machinery service organizations to manage orders, schedule jobs, monitor agricultural machinery and operators, and manage relevant information under the organization [15-16]. the main content of agricultural machinery operation assistance decision-making includes: agricultural machinery dynamics and theme dynamics on the homepage, operation analysis, emergency management of emergency and temporary orders and emergencies, operation quality monitoring, service organization management, and user management. these can be utilized by government users to monitor and manage agricultural machinery service organizations, work quality, and emergency events, help farmers expand orders, and conduct statistics and analysis on various data of agricultural production and agricultural machinery service organizations in beijing, providing data support for local agricultural production, economic development, and policy formulation [17]. 2.3. process design according to the main functional requirement of users, the business process of the intelligent agricultural machinery integration system can be divided into six aspects: demand service, order scheduling, agricultural machinery operation, dynamic management, statistical analysis and auxiliary decision-making, as shown in figure 3: farmer agricultural machinery service organization government mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3. business process of intelligent agricultural machinery integration system from figure 3, it can be seen that: demand service: farmers can find agricultural machinery service institutions on this service site and submit their service needs. they can also request their needs from agricultural machinery service institutions and relevant government departments by phone, and then the agricultural machinery institutions and government department staff would complete the filling of the order, and finally inform the farmers of the processing results of the order. order delivery: the agricultural technology promotion agency shall deliver the required machinery and machinery personnel to the designated locations according to the requirements in the order, and carry out agricultural technology promotion for farmers. agricultural machinery operation: the agricultural machinery service agency informs the operator through sms on their mobile phones. the operator drives the agricultural machinery to the work site according to the requirements of the order, carries out agricultural work, and timely transmits work tasks and status information to the system [18]. dynamic supervision: through the data transmitted by the agricultural machinery mobile terminal, the operation path and status of the agricultural machinery are controlled, and real-time positioning of the agricultural machinery and manipulator is carried out. the agricultural machinery operation trajectory points can be replayed, and the operation area can be estimated [19]. demand service service website demand order order scheduling agricultural machinery operation dynamic supervision statistical analysis telephone job quality agricultural machinery service organization information aid decision making mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset statistical analysis: according to the situation of agricultural machinery, machinery operators, and operation time, agricultural machinery service agencies have conducted statistics and analysis on the operation area, crop types, and operation types. assistance in decision-making: the government has conducted real-time understanding of agricultural machinery service institutions, number of agricultural machinery, agricultural machinery operation area, crop types, operation quality, operation time, and other information, providing scientific, comprehensive, and direct data support for the formulation of various agricultural production plans and support subsidy policies in beijing. 2.4. database design the web mapping used in the intelligent agricultural machinery integration system mainly calls the wmts map slicing service and remote sensing image slicing service issued by tianmap.com. remote sensing images are mainly used for the operation quality analysis module under the agricultural machinery operation assistant decision-making system. the wmts (western main transportation services) remote sensing image slicing service released by geoserver is called, and the image data provides real-time and reliable monitoring data for field area, crop types, crop yield estimation, crop maturity, harvesting range, etc., ensuring the statistical analysis and scientific decision-making work of government departments. other spatial data, system business data, and resource data are all stored in the local postgresql database. the system would obtain data uploaded by agricultural machinery mobile terminals from the data center in real-time through service requests, and save the data in the local database for quick use by the intelligent agricultural machinery integration system. the intelligent agricultural machinery integration system is composed of three subsystems, each independent and interrelated, composed of data in the database, separated from each other and not interfering with each other, but some data (such as spatial data) is shared. identify the attribution of data through id identification and grouping in the data table. when designing the database design, all data tables and fields ensure users of different types and permissions according to data, structure, logical relationship and certain data. there is no conflict between data to prevent system errors. the user information table and spatial information table are shown in tables 1 and 2: table 1. user information table field name model meaning lid character varying usergroup id luserid character varying user id loginname character varying username password character varying password login title character varying name lid card character varying id number imobilephone character varying contact number table 2. spatial information table field name model meaning mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gdsid character varying identification id gdstitle character varying place name centerx numeric(10,2) longitude of center point centery numeric(10,2) latitude of center point gdstreelevel smallint layer level among them, the user information table in table 1 includes the user's personal identification id and group id, as well as the user name, password, name, contact number, id number and other basic registered information. the spatial information table shown in table 2 includes basic geographical information of the country and stores spatial information data such as place names, center point coordinates, layer levels, spatial dimensions, etc., at the provincial, municipal, county, township, and village levels, providing sufficient geographic information for displaying electronic maps. 2.5. system data platform services on the intelligent agricultural machinery big data system, based on the analysis of historical data such as agricultural machinery distribution data, agricultural machinery operation data, and agricultural machinery purchase data, the development of agricultural machinery in various regions was analyzed [20]. the analysis of the development of agricultural machinery consists of six aspects, namely: analysis of the number of agricultural machinery owned, analysis of the number of newly purchased agricultural machinery, analysis of the proportion of imported agricultural machinery, ranking of agricultural machinery brands, analysis of agricultural machinery subsidy data, and analysis of agricultural machinery maintenance data. introducing the annual average growth rate into the study of the ownership of agricultural machinery can better reflect the development of agricultural machinery. the year-on-year development rate refers to the relative development rate achieved in the current period compared to the same period last year. its mode is: l −u v = (1) u v represents the year-on-year development speed, l represents the development level of the current period, and u represents the development level of the same period last year. the analysis of agricultural machinery ownership in this article adopts this indicator, such as the development speed calculated by comparing a certain year with the same period of the previous year. the month on month comparison is based on the current data as the reporting period, and the previous data as the base period. the comparison between the reporting period and the base period is the month on month comparison. the change in the number of agricultural machinery is represented by yearon-year growth and month on month growth rate, and the formula is: m p = (2) n rb −rs q= (3) rb mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset among them, p represents year-on-year growth, m represents the quantity of agricultural machinery last year, n represents the quantity this year, q represents the month on month growth rate, r b represents the quantity of agricultural machinery this month, and rs represents the quantity of agricultural machinery in the previous month [21-22]. 3. testing and intelligent agricultural machinery integration system in the network environment, the network environment has a significant impact on the responsiveness of the network environment. the response rate experiment in this article aims to detect changes in the corresponding response time of the system as there are more and more concurrent requirements in the system. the calculation of response time is a request made from the client. after it arrives at the server, it undergoes a series of interactions (such as reading request files, querying relevant database information, etc.), and then returns to the client from the server to complete the response. in some testing tools, the response time is referred to as ttlb, as shown in figure 4: figure 4. response time statistics as shown in figure 4, the response time increases with the increase of concurrency, with an average response time of 236ms, a maximum response time of 698ms, and a minimum response time of 178ms when the concurrency is 100. when the concurrency is 1000, the average response time is 798ms, the maximum response time is 1236ms, and the minimum response time is 514ms. 0 200 400 600 800 1000 1200 1400 100 200 300 400 500 600 700 800 900 1000 type average response time minimum response time maximum response time mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. conclusions mechanised agriculture is a key indicator of agricultural modernization. in this process, modern computer technology should be brought into full play to build a set of agricultural machinery service management integration system suitable for the the internet age. this would help to improve the level of china's agricultural machinery informatization, strengthen the macro control of government departments on mechanised agriculture, and promote the overall development of mechanised agriculture and informatization. a set of agricultural machinery informatization service management system that matches the economic system can be constructed. this is a major method of combining agricultural production with information technology. in recent years, information technology has been increasingly applied in agricultural production, and digitalization of agricultural machinery service management is a representative example of the development of agricultural informatization. building a new model of agricultural machinery service management can help agricultural machinery service organizations schedule orders in a timely manner during busy agricultural seasons, manage all agricultural machinery and operators under them, and quickly provide agricultural machinery services to farmers. this has completely transformed the traditional management methods of agricultural machinery services, making the intelligent and information-based development of agricultural machinery operation services possible. references sun wei. "design of condenser air filter integrated device for self-cleaning agricultural air conditioning." journal of engineering mechanics and machinery 6.1 (2021): 94-97. pimonratanakan sudarat. "the causal factors that influence the organization performance of the agricultural machinery industry." agbioforum 24.1 (2022): 72-82. abuselidze george, and anna slobodianyk. "marketing aspects of the key issues of agricultural machinery in the industrial enterprises." journal of optimization in industrial engineering 15.1 (2022): 311-320. tian hongkun. "computer vision technology in agricultural automation—a review." information processing in agriculture 7.1 (2020): 1-19. tripathi mukesh kumar, and dhananjay d. maktedar. "a role of computer vision in fruits and vegetables among various horticulture products of agriculture fields: a survey." information processing in agriculture 7.2 (2020): 183-203. bolandnazar, elham, abbas rohani, and morteza taki. "energy consumption forecasting in agriculture by artificial intelligence and mathematical models." energy sources, part a: recovery, utilization, and environmental effects 42.13 (2020): 1618-1632. rotz sarah. "the politics of digital agricultural technologies: a preliminary review." sociologia ruralis 59.2 (2019): 203-229. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sambasivam g. opiyo gd. "a predictive machine learning application in agriculture: cassava disease detection and classification with imbalanced dataset using convolutional neural networks." egyptian informatics journal 22.1 (2021): 27-34. suchithra m. s., and maya l. pai. "improving the prediction accuracy of soil nutrient classification by optimizing extreme learning machine parameters." information processing in agriculture 7.1 (2020): 72-82. ma ling, mohammad ikbal, and korhan cengiz. "realization of agricultural machinery equipment management information system based on network." international journal of agricultural and environmental information systems (ijaeis) 12.3 (2021): 13-25. alimova z. "ways to improve the performance of hydraulic oils for agricultural machinery." industrial technology and engineering 3.36 (2020): 17-22. sobirjonov abutolib, et al. "prevention of corrosion and accelerated wear of agricultural machinery." ilkogretim online-elementary education online 20.5 (2021): 7482-7486. han jialin. "a multi-objective districting problem applied to agricultural machinery maintenance service network." european journal of operational research 287.3 (2020): 1120-1130. romek dawid. "the impact of padding weld shape of agricultural machinery tools on their abrasive wear." tribologia 290.2 (2020): 55-62. pajurek marek, szczepan mikolajczyk, and malgorzata warenik-bany. "engine oil from agricultural machinery as a source of pcdd/fs and pcbs in free-range hens." environmental science and pollution research 30.11 (2023): 29834-29843. muller malte. "leadership in agricultural machinery circles: experimental evidence from tajikistan." australian journal of agricultural and resource economics 64.2 (2020): 533-554. [17] liu ye. "research on the optimized management of agricultural machinery allocation path based on teaching and learning optimization algorithm." tehnički vjesnik 29.2 (2022): 456-463. [18] hui xianghui. "trend prediction of agricultural machinery power in china coastal areas based on grey relational analysis." journal of coastal research 103.si (2020): 299-304. li huaxia. "application of a multi-disciplinary design approach in a mechatronic engineering toolchain." atautomatisierungstechnik 67.3 (2019): 246-269. luque-vega, luis f. "educational methodology based on active learning for mechatronics engineering students: towards educational mechatronics." computacióny sistemas 23.2 (2019): 325-333. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset frey cheolgi. internal combustion engine in agricultural machinery field relying on artificial fish swarm algorithm. kinetic mechanical engineering (2022), vol. 3, issue 1: 18-27. wu j., tao r., zhao p., martin n. f., & hovakimyan n. (2022). optimizing nitrogen management with deep reinforcement learning and crop simulations. in proceedings of the ieee/cvf conference on computer vision and pattern recognition (pp. 1712-1720). mailto:topacademicjournals@gmail.com 格式 academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a comprehensive approach to railway landslide risk assessment using hierarchical grey relation analysis 1he, xiao-rong and 2ji, yu-tong 1baoji electric service section of xi'an railway bureau, baoji, 721000, china 2baojidong railway station of xi'an railway bureau, baoji, 721000, china abstract: the west sichuan railway in china traverses challenging terrain characterized by steep slopes and a high seismic activity, leading to the frequent occurrence of landslides and other geological disasters during both construction and operation. landslides pose a substantial threat to passenger safety and railway infrastructure. in the chengdu baiyu section alone, 126 landslides have been recorded, emphasizing the urgency of landslide risk assessment and prevention [1]. landslide risk refers to the likelihood of slope failures evolving into various forms of disasters under the influence of multiple factors [3]. this study focuses on enhancing landslide risk assessment by optimizing the selection of evaluation factors. previous research has explored various methods for factor selection and evaluation models in landslide risk assessment. one approach employed rough set analysis, correlation analysis, and principal component analysis to identify landslide evaluation factors, subsequently utilizing support vector machine models for landslide susceptibility evaluation [4]. this method demonstrated improvements in evaluation accuracy by reducing and refining evaluation factors. another study applied the apriori algorithm for correlation analysis of landslide evaluation factors and employed the random forest model for landslide susceptibility evaluation, resulting in more accurate evaluation results closely aligned with actual landslide distribution [5]. additionally, genetic algorithms and rough set analysis were employed to screen landslide evaluation factors, coupled with bp neural networks for landslide susceptibility evaluation, revealing higher evaluation model accuracy with reduced factors [6]. models like bp neural networks, support vector machines, logistic regression, and random forest have consistently shown strong performance in landslide susceptibility assessment [7][8][9][10]. in a comparative study, the random forest model outperformed logistic regression, multilayer perceptron, and gradient enhancement tree models in landslide risk assessment [11]. however, a gap exists in the selection of evaluation factors as some studies have neglected to consider the contribution of these factors to landslide events, potentially compromising calculation efficiency and evaluation accuracy. furthermore, the conventional data analysis method for factor screening often involves calculating the contribution rate of factors, which may introduce errors and outliers into the evaluation factor data extracted from landslide events. this could lead to the inadvertent elimination of important factors during data calculation and analysis, ultimately affecting the accuracy of evaluation results. therefore, this study seeks to address these limitations by proposing a novel approach to evaluate landslide risk that incorporates a comprehensive consideration of evaluation factors and employs advanced data analysis techniques. keywords: landslide risk assessment, evaluation factors, factor selection, data analysis, random forest model mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1. introduction the terrain along the west sichuan railway in china is steep, with frequent occurrence of moderate to strong earthquakes. the geological environment along the railway is complex, and geological disasters such as landslides, collapses, and mudslides may occur during construction and operation [1]. landslides pose a serious threat to the lives and property of passengers and railway lines. according to preliminary statistics, there are 126 landslides along the chengdu baiyu section of the railway [2]. landslide danger refers to the possibility of slope sliding and transforming into various forms of disasters under the combined action of multiple influencing factors [3]. the risk assessment of landslides can provide technical support for landslide prevention and control, and the reasonable selection of landslide evaluation factors is an important part of risk assessment. there have been studies on different methods for selecting factors and evaluating models in landslide risk assessment. reference [4] used rough set, correlation analysis, and principal component analysis to screen landslide evaluation factors, and used support vector machine models for landslide susceptibility evaluation. experimental examples showed that screening and reducing evaluation factors can improve the accuracy and accuracy of evaluation results; literature [5] uses the apriori algorithm to carry out correlation analysis on landslide evaluation factors and screen factors, and uses the random forest model to evaluate landslide susceptibility. the experimental results show that the apriori algorithm is used to select factors from the preselected factors that are more likely to cause landslides, and the evaluation results obtained are more consistent with the actual landslide distribution; reference [6] used genetic algorithm and rough set to screen landslide evaluation factors, and used bp neural network for landslide susceptibility evaluation, indicating that the reduced factors correspond to higher accuracy of the evaluation model; bp neural network [7], support vector machine [8], logistic regression [9] and random forest [10] models have shown good performance in landslide susceptibility assessment; the literature [11] uses random forest for landslide risk assessment, and compares it with logistic regression, multilayer perceptron and gradient enhancement tree. the results show that the accuracy rate of landslide risk assessment results obtained by random forest model is the highest. in the above studies, in terms of selecting evaluation factors, some studies have directly selected factors related to landslide events for risk assessment, without considering the contribution of evaluation factors to landslide events, which can easily affect calculation efficiency and accuracy of evaluation results; in terms of evaluation factor screening, the data analysis method is often used to calculate the contribution rate of factors for factor screening. however, there are errors and outlier in the evaluation factor data extracted from landslide events. when some important factors are eliminated due to data calculation and analysis, the evaluation results will be affected to a certain extent. to address the issue of mistakenly removing important evaluation factors based on their contribution rate, expert experience and calculation of evaluation factor contribution rate are introduced for factor screening. firstly, the analytic hierarchy process is used to calculate the subjective weights of the pre-selected factors. then, grey correlation analysis is used to calculate the correlation degree of the pre-selected factors, and a distance function is introduced to calculate the comprehensive correlation degree of the evaluation factors based on subjective weights and grey correlation degree. then, the evaluation factors are sorted according to the comprehensive correlation degree from large to small, and the first n factors are used as evaluation factor combinations, which mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset are input into the random forest model. the final evaluation factor combinations are selected according to the prediction accuracy of the model to complete the screening of evaluation factors, and the importance of evaluation factors is calculated through the random forest. finally, arcgis is used to stack the factor layers, calculate the landslide risk and generate the landslide risk distribution map in the study area, and complete the landslide risk assessment along the railway. 2. research methods 2.1 analytic hierarchy process the analytic hierarchy process (ahp) is a comprehensive evaluation model method. through hierarchical and quantitative means, the relevant elements of decision-making problems are divided into multiple levels such as objectives, criteria, and indicators, and a multi-criteria analysis and decision-making method combining qualitative and quantitative analysis [12]. its use steps are as follows: (1) the landslide risk assessment is selected as the target layer, the geological conditions, topographic conditions, and trigger conditions are selected as the criterion layer, and then the initial disaster causing factors are selected as the index layer to build the initial evaluation system; (2) the evaluation indexes in the same layer of landslide risk evaluation system are compared and scored, and the judgment matrix is constructed; (3) the weight w1 of each index is obtained by mathematical calculation; (4) the consistency index ci and random consistency index cr are introduced to test the consistency of each judgment matrix. λmax −n ci = (1) n−1 ci cr = (2) ri 2.2 hierarchical grey relational analysis landslide is a kind of disaster formed by the influence of many factors, in which the influencing factors are complex and vague, so the occurrence of landslide disaster can be regarded as a grey system. grey correlation analysis measures the correlation degree between the comparison sample and the reference sample according to the similarity between the indicators [13], to determine the correlation degree of each indicator. the steps of grey correlation analysis are as follows: (1) construct a sample matrix, a total of n groups of samples, each group of samples has a total of m indicators; (2) determine the reference sample, which is composed of the optimal value or the worst value of each disaster causing factor; (3) due to the different dimensions of a disaster causing factors, the normalized sample matrix is obtained by averaging them; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset x0(1) x (2) （x x0, 1, xn）= 0 x m0( ) x1(1) x1(2) x m1( ) xn(1) xn(2) x mn( ) (4) calculate the absolute difference between each comparison sample and the reference sample, that is x k0( )− x ki ( ) ,k =1,2, ,m i; =1,2, ,n , secondly calculate the maximum and minimum values of all absolute differences; (5) calculate the correlation coefficient; n m n m minmin x k0 ( )− x ki +ρmaxmax x k0 ( )− x ki ξi ( )k = i=1 k=1 n i=m1 k=1 (3) x k0 ( )− x ki +ρmaxmax x k0 ( )− x ki i=1 k=1 in equation (3) p is the resolution coefficient, generally 0.5[14]. (6) the average method is used to calculate the correlation degree; 1 m ri = ∑ξi ( )k (4) m k=1 (7) the normalized grey correlation degree w2 is obtained by normalizing the correlation degree; (8) the distance function[15] is introduced to calculate the comprehensive correlation degree combined with ahp weight and normalized grey correlation degree. ，w2 ) = 1 ∑m (wi1 −wi2 )2 (5) l w( 1 2 i=1 let the comprehensive correlation degree be w and the coefficients of ahp weight and grey correlation degree be a and b respectively, then w is: w = aw1 +bw2 (6) make the difference between grey correlation degree and ahp weight consistent with the difference between distribution coefficients, to eliminate the influence of human factors and data singularity, and obtain relatively objective and accurate results. therefore, the following constraints are used to calculate the correlation coefficient. l w2 ( 1，w2 ) = −(a b)2 (7) a+ =b 1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.3 association rules association rules are one of the important means of data mining, which mainly refers to finding the correlation of different items in the same event, that is, the correlation between different items in the transaction database [16]. the total set of the chronicle database is x. if subsets a and b of the total set x meet a⊂x,b⊂x, and a∩b=⌀, a⇒b is called association rule, where a and b are the premise and consequence of association rule respectively. support is the percentage of a∪b in transaction database x, as shown in equation (8): support a( => =b) p a( b) (8) calculate the support degree of landslide caused by each disaster causing factor, and use the support degree to test the rationality and accuracy of landslide disaster causing factor screening [17]. 2.4 random forest random forest (rf) is a combined classifier in machine learning algorithm. n samples (n < n) are retrieved from n sample sets, k attributes (k < k) are selected from k total attributes, and the best segmentation attributes are selected based on gini index to create a decision tree. multiple decision trees can be integrated through bagging algorithm to form a random forest [18]. random forest training is fast, not easy to "over fit", and has a good tolerance for noise and outliers [19]. the importance of rf is calculated based on gini index. the calculation formula of gini index is as follows: n gini a( ) = −1 ∑ pi 2 (9) i=1 m gini a b( , ) =∑gini a( j ) (10) j=1 in formula (9), n is the number of classification categories in sample a (whether landslide disaster occurs); pi is the proportion of class i samples in sample a. in equation (10), gini (a, b) is the gini index after dividing sample a by factor b; m is the total number of samples| aj | is the number of j samples. after averaging the importance results output from each decision tree, it is the importance of the random forest. 3. landslide risk assessment model the flow chart of landslide risk assessment is shown in figure 1. j a a mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: flow chart of landslide risk assessment (1) firstly, score the initial evaluation index system and construct the judgment matrix, so as to calculate the subjective weight of each factor and test the consistency of the judgment matrix. at the same time, the grey correlation method is used to analyze the initial indexes and calculate the grey correlation degree of each factor. the comprehensive correlation degree is calculated by using the distance function, (2)the factors are sorted according to the comprehensive correlation degree from large to small. take the first n factors and input them into the random forest model. select the corresponding factor combination with the highest accuracy, eliminate the factors that do not appear in the factor combination, and complete the factor screening. then the association rules are used to calculate the support of each factor to verify the rationality and accuracy of factor screening. (3) after the factor screening, use the random forest to calculate the importance of each factor, set and optimize multiple parameters in the random forest, improve the classification accuracy of the model, and obtain the importance of each factor. use arcgis to assign values and overlay analysis to each factor layer, calculate the landslide risk size and generate the landslide risk distribution map, and complete the landslide in ya'an-batang section of sichuan-tibet railway risk assessment. 4. research area and data source 4.1 overview of the study area figure 2 is the railway route map of ya'an city. ya'an city is complex and changeable, the fault structure is developed, the geological disasters are many and wide, the dangerous situation is serious and the harm is great, and the rainfall frequency is intensive from june to august every year. the rainfall is mostly heavy rain and heavy rainstorm, and the landslide types are mostly rainfall type landslide and earthquake type landslide. the triggering analytic hierarchy process grey relation analysis comprehensive relevance ranking initial landslide risk evaluation index system random forest landslide risk assessment mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset conditions of landslide disaster in this study only consider rainfall and human engineering activities, not the earthquake. figure 2: study area 4.2 data sources based on the existing research[20,21], 12 disaster causing factors are selected, namely rainfall, formation lithology, distance to fault, land use type, slope, elevation, slope direction, plane curvature, profile curvature, distance to river, vegetation coverage and human engineering activities. these factors can comprehensively present the geological conditions, topographic conditions, and triggering conditions of landslide disasters in the study area. the data sources are as follows: the rainfall data is from the china meteorological data network. the maximum 24h rainfall in the current rainfall process is selected to represent the rainfall factor; the data of formation lithology and distance to fault are from the national geological data center; land use types and landslide disaster distribution are derived from the resource and environmental science and data center; the distance to the river is derived from the basic geographic information database; human engineering activities are represented by road buffer zone and residential area, and the road buffer zone originates from osm(https://www.openstreetmap.org/), the residential area originates from network collection; landsat8 and dem data are derived from geospatial data cloud, vegetation coverage is extracted from landsat8, and slope, aspect, plane curvature, and section curvature are extracted from dem. 5. example analysis and discussion 5.1 subjective weight calculation based on ahp the initial landslide risk evaluation index system is constructed according to 12 initial hazard factors, as shown in figure 3. the evaluation indexes are scored, the judgment matrix a is constructed based on the geological conditions, topographic conditions and trigger conditions in figure 3, and the judgment matrices b1, b2 and b3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset are constructed based on the hazard factors under geological conditions, topographic conditions and trigger conditions. figure 3: initial landslide risk evaluation index system 6 3 4 4 4 4 4 2 1 3 2 1 5 2 3 5 3 1 5 3 3 4 3 5 1 11 9 3 4 1 2 4 5 5 1 5 2 6 10 10 4 3 b3= 1 a= 1 4 3 2 10 4 2 9 1 3 4 b1= 1 2 3 3 6 3 11 5 5 10 3 4 1 b2= 1 4 5 5 3 10 5 2 6 2 5 3 1 5 4 9 4 1 3 5 1 2 2 6 5 4 5 3 1 2 4 3 2 2 5 3 10 5 1 1 7 4 9 6 2 the eigenvectors of each judgment matrix are calculated, and the eigenvectors of each disaster causing factor are obtained importance w1, check the consistency of each judgment matrix through equations (1) and (2), as shown in table 1. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset w1=(0.062,0.081,0.064,0.054,0.057,0.055,0.049,0.058,0.87,0.052,0.253,0.127) table 1: consistency test results of each judgment matrix a b1 b2 b3 λ ci cr 3.0015 0.0007 0.0015 4.0471 0.0157 0.0176 6.0300 0.0060 0.0047 2 0 0 5.2 calculation of correlation degree of disaster causing factors based on grey relation 12 preselected factors such as fault distance and formation lithology are selected as the indexes of grey correlation analysis. the extracted initial landslide data are processed by the mean method, and the reference samples are determined: x0=(1.6,2,1.02,1.33,1.42,1.6,2.3,1.2,1.1,1.2,1.42,1.17) calculate the absolute difference between the comparison sample and the reference sample, and determine the maximum and minimum values of the absolute difference. the correlation degree is calculated according to equations (3) and (4): r=(0.872,0.548,0.499,0.476,0.831,0.85,0.502,0.899,0.923,0.542,0.893,0.881) the grey relation degree is normalized to: r1=(0.1,0.063,0.057,0.055,0.095,0.098,0.058,0.103,0.106,0.062,0.102,0.1) the comprehensive relation degree obtained from equation (5) is: z=(0.081,0.071,0.06,0.054,0.076,0.076,0.053,0.08,0.096,0.055,0.177,0.11) 5.3 factor screening and inspection rank the factors in the comprehensive correlation degree z from large to small, take the first n factors as data sets and input them into the random forest model (n = 5, 6,..., 12). roc curve is called sensitivity curve, which has been widely used in the accuracy analysis of geological hazard risk assessment results[22]。 auc represents the area under the roc curve. the closer the auc value is to 1, it shows that the discrimination result of the model is better. as shown in figure 4, after inputting the random forest model through different factor combinations, the roc curve is generated and the auc value is calculated. when n = 8, the corresponding model accuracy is the largest, and the auc value is 0.89. therefore, keep these 8 factors, eliminate the distance to fault, distance to the river, plane curvature, and section curvature, and complete the factor screening. the association rule formula (8) is used to calculate the support of the above-retained factors, and the obtained support is 0.94, 0.941, 0.824, 0.912, 0.81, 0.891, 0.906, and 0.912, which are greater than 0.8. therefore, this method is reasonable for screening landslide risk assessment indicators. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: test results of random forest roc curve of eight factor combinations python is used to calculate the importance of each factor in the random forest model. firstly, the size of each parameter is set, and then the parameters are adjusted. the optimal values of each parameter are obtained by grid search and 10 fold cross verification. finally, the importance w2 of the eight factors of rainfall, human engineering activities, slope, stratum lithology, vegetation coverage, slope direction, elevation, and land use type is obtained through feature_importances function. w2=(0.201,0.17,0.154,0.141,0.102,0.096,0.072,0.063) 5.4 landslide risk assessment in the study area on the basis of each factor layer, the important weight is given to each layer by using the spatial superposition function of arcgis, and the landslide risk distribution map of the study area is generated, as shown in figure 5. based on the natural breakpoint method, the landslide risk evaluation results are divided into five levels: low, low, medium, high and high risk. it is generally believed that the high-risk and high-risk areas are vulnerable to landslides. when 97 landslide verification points are used to test the landslide risk assessment results, it can be obtained that 89.7% of the landslide points are located in the high-risk and high-risk areas, that is, it is considered that the verification accuracy is 89.7%. according to the statistical analysis of the risk assessment results in figure 5, the railway lines in high and high-risk areas are 10.9 km (2.1%) and 48.7 km (9.4%) respectively and are mostly distributed in ya'an area. the main reason is that ya'an has large rainfall, which is easy to reduce the shear strength of the slope and accelerate the disintegration and destruction of the slope. among them, the maximum 24h rainfall in august 2020 is 425.2mm, reaching an all-time high. at the same time, human engineering activities in this area are strong, roads and residential areas are densely distributed, which provides a good disaster pregnant environment for the landslide. for the above high-risk lines, it is recommended to use scientific means to monitor the dangerous slopes during line construction, and take preventive measures against landslides in advance, so as to prevent landslides from causing huge damage to the railway line. during the later operation of sichuan-tibet railway, the landslide hazard assessment results are closely combined with the railway signal early warning system to ensure the safe operation of trains and the safety of lines, and provide a safety guarantee for railway operation. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: landslide risk zoning map of the study area 5.5 accuracy verification of different models the random forest model is combined with the support vector machine (svm) model and logistic regression model commonly used in landslide risk assessment (lr) to compare the model accuracy before and after screening factors. as shown in figure 6, the accuracy of random forest model before screening factors is the largest, and its auc area is 0.82. after comprehensive correlation screening factors and random forest parameter optimization, the auc area of random forest model is increased to 0.91, which is greater than 0.81 of logistic regression and 0.85 of support vector machine. (a)test results of roc curve of each model without screening factor mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (b) roc curve test results of each model after screening factors figure 6: roc curve verification 6. conclusion based on the grey correlation and ahp screening factors, the random forest model is used to evaluate the landslide risk. taking ya'an city railway lines as the research object, the following conclusions are obtained: (1) the grey relation and analytic hierarchy process are used to comprehensively screen the factors, which solves the problem of false deletion of factors due to a small grey correlation degree. the results show that rainfall, slope, human engineering activities, formation lithology, vegetation coverage, slope direction, elevation, and land use type are strongly related to the occurrence of landslide disaster in ya'an city railway lines. (2) the random forest model is used to evaluate the landslide risk, and the roc curve is used to evaluate the accuracy of the random forest model. the area under the roc curve before the screening factor is 0.82, and the area under the roc curve after the optimization of the screening factor and random forest parameters is 0.91. it is proved that the optimization of the screening factor and model parameters can improve the accuracy of the evaluation model. (3) the landslide risk assessment results obtained based on the research method in this paper are consistent with the landslide disaster verification points in sichuan province, which proves that the research method in this paper is reliable, accurate and has certain practical value. it can provide some result reference and technical support for the medium-term construction and later operation management of ya'an railway. references lu cf, cai cx, 2019. challenges and countermeasures for construction safety during the sichuan–tibet railway project. engineering, 5(05):49-61. doi: cnki:sun:goch. 0. 2019-05-010. [2] li xz, cui y, zhang xg, et al., 2019. characteristics and spatial distribution law of landslides and collapses along sichuan-tibet railway. journal of engineering geology, 27(s): 110-120. doi:10. 26914/c. cnkihy. 2019. 014704. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wang ting, 2020. landslide risk assessment based on combined analysis of weight method and simulation method: a case study of parts of wanyuan city. doi: 10. 26986/d. cnki. gcdlc. 2020. 000805. yu xy, hu yj, niu rq, 2016. research on the method to select landslide susceptibility evaluation factors based on rs-svm model. geography and geo-information science, 32(03): 23-28+2. doi: cnki: sun: dlgt. 0. 2016-03-005. liu r, li ly, yang x, et al., 2021, landslide susceptibility mappping based on factor strong correlation analysis method[j]. earth and environment, 49(02):198-206. doi: 10. 14050/j. cnki. 1672-9250. 2020. 48. 108. tang rx, yan ec, tang w, 2017. landslide susceptibility evaluation based on rough set and back-propagation neural network [j]. coal geology & exploration, 45(06):129-138. aditian a, kubota t, shinohara y, 2018. comparison of gis-based landslide susceptibility models using frequency ratio, logistic regression, and artificial neural network in a tertiary region of ambon, indonesia. geomorphology, 318:101-111. doi:10. 1016/j. geomorph. 2018. 06. 006. huang y, zhao l. 2018. review on landslide susceptibility mapping using support vector machines. catena, 165: 520−529. doi:10. 1016/j. catena. 2018. 03. 003. luigi l, martin m p. 2018. presenting logistic regression-based landslide susceptibility results. engineering geology, 244: 14−24. doi:10. 1016/j. enggeo. 2018. 07. 019. wu xq, lai cg, chen xh, et al. a landslide hazard assessment based on random forest weight:a case study in the dongjiang river basin, journal of natural disasters, 2017, 26(05): 119-129. doi: 10. 13577/j. jnd. 2017. 0514. ahmed n, firoze a, rahman rm. 2020. machine learning for predicting landslide risk of rohingya refugee camp infrastructure. journal of information and telecommunication, 4(2): 175-198. doi: 10. 1080/ 24751839. 2019. 1704114. wang jh, jin hl, ni tx, et al., 2017. the application of fuzzy comprehensive evaluation model based on analytic hierarchy process in risk assessment of debris flow gully in kangle county. the chinese journal of geological hazard and control, 28(03):52-57. doi: 10. 16031/j. cnki. issn. 10038035. 2017. 03. 08. huang f, wang y, dong zhiliang, et al., 2019. regional landslide susceptibility mapping based on grey relational degree model. earth science, 44(02):664-676. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset jaiswal p, van. w c j, jetten v. quantitative assessment of direct and indirect landslide risk along transportation lines in southern india[j]. natural hazards and earth system sciences, 2010, 10(6):12531267.doi:10.5194/nhess-10-1253-2010. zhang c, wang q, chen jp, et al., 2011. evaluation of debris flow risk in jinsha river based on combined weight process. rock and soil mechanics, 32(03):831-836. doi: 10. 162 85/ j. rsm. 2011. 03. 019. tan gs, cao sx, zhao b, et al., 2020. an assessment of power transformers based on association rules and variable weight coefficients. power system protection and control, 48(01): 88-95. doi: 10. 19783/j. cnki. pspc. 190072. song rj, liu ry, liu yw, et al., 2018. key indicator system establishment and application for transformer condition assessment based on hierarchy grey relation analysis. high voltage engineering, 44(08):2509-2515. doi: 10. 133 36/j. 1003-6520. hve. 20180731010. zhang wq, luo gp, zheng hw, et al., 2020. analysis of vegetation index changes and driving forces in inland arid areas based on random forest model: a case study of the middle part of northern slope of the north tianshan mountains. chinese journal of plant ecology, 44(11): 1113-1126. breiman l. 2001. random forests. machine learning, 2001, 45(1): 5-32. doi: 10. 1023/a: 1010933404324. yang zj, ding pp, wang d, et al., 2018. landslide risk analysis on et a sichuan-tibet railway (kangding to nyingchi section) journal of the china railway society, 40(09): 97-103. doi: cnki: sun: tdxb. 0. 2018-09-015. wang wd, fu qx, tang r. 2018. landslide spatiotemporal susceptibility analysis of chengdu-yaan section in sichuan-tibet railway. journal of railway science and engineering, 15(04): 862-870. doi:10. 19713/j. cnki. 43-1423/u. 2018. 04. 006. reichenbach p, rossi m, malamud b d, et al. a review of statistically-based landslide susceptibility models [j]. earth-science reviews, 2018, 180, 60-91. mailto:topacademicjournals@gmail.com beginning at a very young age, today’s students are schooled at home (and just about everywhere else) by television academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset antioxidants from amazonian vegetables: a potential source of natural medicine mariana a. perez-chavez, juan c. ramirez-gonzalez and luisa d. sanchez-flores national university of the peruvian amazon, iquitos peru abstract: the amazon rainforest is home to a vast diversity of plant species, many of which have been used for medicinal purposes by indigenous peoples for centuries. this study investigated the antioxidant activity of plant species collected from the tamshiyacu-tahuayo communal regional conservation area (acr ctt) in peru. the antioxidant activity of the plant extracts was determined using the dpph assay. the results showed that the plant extracts had significant antioxidant activity, with some extracts exhibiting more activity than commercial antioxidants. the findings of this study suggest that the plant species from the acr ctt have potential as sources of natural antioxidants. keywords: amazon rainforest, medicinal plants, antioxidant activity, dpph assay, natural antioxidants 1. introduction certain amazonian plant species among its many utilities that ethnobotany mentions, is its use as medicinal plants that have been used by the inhabitants of this region since time immemorial and, thanks to the studies of various researchers, it has become known and valued for a proper use of them (duke & vasquez, 1994) the town of tamshiyacu is the capital of the district of sargento lores in the loreto region and its primary forests belong for the most part to the tamshiyacu tahuayo communal regional conservation area of peru (acr ctt). located in zone 18 of the utm projection system, between coordinates 680 075 e, 9 528 176 n and 768 162 e, 9 444 073 n. it has an area of four hundred twenty thousand and eighty hectares with two thousand five hundred square meters (420,080, 25 ha), (gobierno regional de loreto, 2011); (shoobridge, et al., 2004). the antioxidant activity is considered as the sequestration of free radicals, which are found in excess, in the human organism they are considered to cause various pathologies that include aging, cancer, arteriosclerosis and other diseases in humans, (ibarra et al., 2011). the main organic molecules provided by the plant species that manage to sequester these free radicals are mainly phenolic compounds, some alkaloids and vitamins a, e and c, (coronado, et al., 2015). the objective of the present study was to perform the evaluation of the antioxidant activity of the foliar samples of 31 plant species of the amazonian forest of the tamshiyacu locality and to select the three best with high activity, 2. materials and methods 2.1. materials collection of plant material: leaves of 31 plant species were collected in the vicinity of the town of tamshiyacu and are shown in table 1. the exsicatas were deposited in the herrerense herbarium of the research institute of the peruvian amazon (iiap). evaluation of antioxidant activity. with the samples of the dried and powdered leaves, the methanolics extracts were prepared with some concentrations of 0.25; 0.1; 0.05 and 0.01 mg/ml. to determine the antioxidant activity, we used the uv/vis spectrophotometer equipment, specturlamb brand 22 pc. (kerlab). in a 1.5 ml polystyrene mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cuvette, 25 μl of the methanolic extract and 975 μl of 0.1 mmol dpph solution were added, then the absorbance was measured at a wavelength of 517 ηm, the readings were performed for 5 minutes with 30 second intervals, all reactions were performed in triplicate. the inhibition of dpph radical sequestration by increasing solutions of the extracts was determined by the following expression, (sotero et al., 2011). % inhibition dpph = [(ac – am)/ac] 100 where: ac, is the absorbance of the control (0.1 mmol of dpph), and am, is the absorbance of the sample (increasing solutions of the extracts) in a time n. 2.2. methods phenolic compounds: for the extraction of phenolic compounds, the technique of (valls et al., 2000) is as followed: 0.5 g of the sample is weighed and extracted successively with 3 volumes of 25 ml of ethanol acidulated with 1% formic acid. the extract is concentrated in a rotary evaporator at 40 °c. the dry residue is redissolved in a 50% methanol solution acidified with a formic acid solution, and brought to a volume of 10 ml. this is stored for subsequent analyzes. table 1. list of 31 plant species collected in the vicinity of the town of tamshiyacu, loreto-peru. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset registry collector order/families species georeference utm 1 paa malpighiales/ euphorbiaceae sapium sp. 18m 0714538 9555251 2 paa magnoliales/ myristicaceae virola. sebifera 18m 0714538 9555249 3 paa magnoliales/ annonaceae oxandra sp. 18m 0714501 9555241 4 paa magnoliales/ myristicaceae virola. sebifera 18m 0714495 9557062 5 paa magnoliales/ myristicaceae iryanthera cf. laevis 18m 0714497 9555242 6 paa magnoliales/ annonaceae cymbopetalum cf.longipes 18m 0714451 9555237 7 paa rosales/ moraceae ficus cf. americana 18m 0704508 9560836 8 paa fabales/ fabaceae parkia cf. multijuga 18m 0704522 9560848 9 paa rosales/ moraceae brosimum parinaroides. 18m 0704985 9561001 10 paa gentianales/ apocynaceae couma macrocarpa. 18m 0705215 9561180 11 paa magnoliales/ annonaceae xylopia cf. benthamii 18m 0705289 9561177 12 paa malpighiales/ caryocaraceae caryocar glabrum 18m 0705951 9558757 13 paa magnoliales/ annonaceae guatteria cf. hyposericea 18m 0705964 9558755 14 paa sapindales/ anacardiaceae tapirira guianensis 18m 0705988 9558712 15 paa magnoliales/ myristicaceae virola cf. surinamensis 18m 0706268 9559258 16 paa gentianales/ apocynaceae llacmelleasp. 18m 0711608 9557071 17 paa magnoliales/ annonaceae guatteria cf. flabellata 18m 0711617 9557063 18 paa fabales/ fabaceae dialium cf. guianense 18m 0711612 9557072 19 paa rosales/ moraceae helicostylis cf. tomentosa 18m 0711610 9557062 20 paa rosales/ moraceae helicostylis cf. turbinata 18m 0711623 9557049 21 paa santalales/ olacaceae mnquartia guianensis 18m 0711855 9556913 22 paa laurales / siparunaceae siparuna cf. sessiliflora 18m 0711854 9556909 23 paa rosales/ moraceae ficus sp. 18m 0711842 9556901 24 paa alismatales/ araceae dracontium cf. amazonense 18m 0711830 9556904 25 paa malpighiales/ clusiaceae vismia cf. macrophylla 18m 0711852 9556899 26 paa caryophyllales/ nyctaginaceae neea cf. divaricata 18m 0711864 9556887 27 paa fabales/ fabaceae zygia cf. macribridei 18m 0711868 9556888 28 paa fabales/ fabaceae diaium sp. 18m 0706244 9561454 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 29 paa gentianales/ apocynaceae malouetia cf. naias 18m 0706538 9561642 30 paa magnoliales/ annonaceae unonopsis cf. sitipitata 18m 0706764 9561927 31 paa ranunculales/ menispermaceae curarea cf. toxicofera 18m 0706669 9561534 anthocyanins and total flavonoids: the determination of anthocyanins and total flavonoids is performed by uv/vis spectrophotometry in 1ml of the extract prepared for the phenolic compounds by reading the absorbance at 535 ηm and 374 ηm respectively, after dilution of the samples. to perform the calculations, the molar extinction coefficient of malvidin-3-glucoside is used: 29500 l/mol cm. catechin and proanthocyanidins: it is done by the vanillin test. 0.5 ml of the extract is mixed with 1.25 ml of vanillin in 1% methanol (w/v) and with 1.25 ml of 25% sulfuric acid (v/v) in methanol. the white is prepared simultaneously in the same way, but replacing the vanillin solution with methanol. it is left to rest for 15 minutes and then the absorbance reading is made at 510 ηm. total phenolic compounds: measurement of the folin index is carried out, for which 40 μl of the extract prepared for phenolics are treated, with 0.5 ml of folin-ciocalteau reagent and 2ml of 20% sodium carbonate (w/v), and they are taken to 10 ml. after half an hour, the absorbance reading is carried out at 765 ηm. to establish the calibration, catechin standards of concentrations between 0 100 mg/l are used. alkaloids: the method indicated by shamsa et al., (2008), is used, 5 g dry pulverized sample is weighed and extracted with methanol in soxhlet equipment for 12 continuous hours. the extract was filtered and the methanol was separated in a rotavapor at 45 ºc, redissolved with 2n hcl and then filtered, 1 ml of this solution was transferred to a decanting pear and washed three times with 10 ml of chloroform. the ph of this solution is neutralized with 0.1 n naoh, 5ml of bcg and 5ml of phosphate buffer are added, the mixture is shaken and the complex formed is extracted with 1, 2, 3, and 4ml of chloroform with stirring. the extracts are collected in a 10ml vial and then filled to volume with chloroform, in this solution is proceeded to perform the absorbance reading at 470 ηm. the data are quantified with a standard curve of atropine. chromatographic fractionation and identification of polar molecules by gas chromatography coupled to mass spectrophotometry (cg-ms). the chromatographic fractionation of methanolic extracts, in open column with silica gel no. 100, of the three species with high antioxidant activity was performed, and identification of the molecules by thin-layer chromatography, grouping the fractions with similar molecules, then they were subjected to gas chromatography equipment with mass spectrometry, using agilent technologies 7890ª ® with an agilent 122-5532 db 5ms ® capillary column of 30 m, with internal diameter of 0.25 mm. the initial temperature of the oven was 100 °c/03 min, followed by a ramp of 20 °c/3 min up to 300 °c/19 min; the maximum temperature of the oven was 325 °c. a split injection was used and the helium gas flow was 2 ml/min. the fragments for the analyses were recorded with the parameters for a scan of 50 to 500 m/z, sotero et al., (2016). 3. results table 2 shows the antioxidant activity of the leaves of the 31 plant samples studied, ordered by families, where all the evaluations of the antioxidant activity of this species are summarized, it is observed that the three species that exceed 50 % inhibition of antioxidant activity at a concentration lower than 5.0 mg/ml are, virola sebifera, caryocar glabrum and tapirira guianensis. tables 5, 6 and 7 show the molecules identified by the gc-ms of the extracts of the species virola sebifera, caryocar glabrum and tapirira guianensis, respectively. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 2. percentages of inhibition of the methanolics extracts of the leaves of the 31 plant species under study at different concentrations, using the dpph method. concentration, mg/ml family species 5,0 0,5 0,25 0,1 0,05 0,01 mg/ml mg/ml mg/ml mg/ml mg/ml mg/ml annonaceae oxandra sp. 32,59 10,01 12,11 18,35 18,37 17,67 annonaceae guatteria hyposericea 44,42 10,37 5,55 3,51 3,17 2,80 annonaceae cymbopetalum.longipes 26,19 0,05 0 0 0 0 annonaceae xylopia benthamii 43,70 9,46 0,51 0,43 0 0 annonaceae guatteria flabellata 45,56 26,74 7,10 3,68 2,40 1,51 annonaceae unonopsis sitipitata 3,15 0 0 0 0 0 apocynaceae couma macrocarpa. 19,48 7,18 4,10 3,26 0,55 1,78 apocynaceae llacmelleasp. 42,11 17,09 10,75 10,90 10,90 10,50 apocynaceae malouetia. naias 27,84 9,52 13,27 21,55 0 0 anacardiaceae tapirira guianensis 79.41 23.53 20.59 11.76 11.76 8.82 araceae dracontium amazonense 25,82 12,69 7,72 7,11 7,08 8,50 caryocaraceae caryocar glabrum 74,25 29.41 23.53 14.71 11.76 5.88 clusiaceae vismia macrophylla 23,87 10,43 7,27 6,23 5,83 6,32 euphorbiaceae sapium sp. 40,56 7,03 11,98 10,78 11,88 16,04 fabaceae parkia multijuga 6,82 1,40 2,81 1,50 0,85 0,10 fabaceae dialium guianense 11,41 3,17 2,08 0,71 0,26 0 fabaceae zygia macribridei 11,49 0 0,27 0 0 0 fabaceae diaium sp. 30,48 5,55 4,09 2,11 2,18 2,42 menispermaceae curarea toxicofera 22,85 2,91 1,37 0 0 0 moraceae brosimum parinaroides. 17,89 3,92 0,84 1,33 1,46 0,36 moraceae helicostylis turbinata 22,21 12,94 13,78 2,36 2,85 4,39 moraceae ficus americana 9,85 0 0 0 0 0 moraceae helicostylis tomentosa 13,10 1,99 4,71 4,56 4,67 4,22 moraceae ficus sp. 34,48 23,94 24,97 24,72 18,53 19,23 myristicaceae virola. sebifera 81.08 40 32.43 24.32 8.11 5.41 myristicaceae virola sebifera 43,16 12,25 9,96 6,52 0,94 0,12 myristicaceae iryanthera laevis 35,22 6,42 5,87 -2,54 -5,89 -6,06 myristicaceae virola surinamensis 46,19 16,80 13,06 7,44 8,52 6,57 nyctaginaceae neea divaricata 10,33 0 0,98 0 0 0 olacaceae mnquartia guianensis 42,25 8,38 4,20 1,65 1,41 2,00 siparunaceae siparuna sessiliflora 21,32 4,64 2,01 2,03 2,52 2,78 table 3. phenolic compounds present in the leaves of three plant species with a high percentage of antioxidant activity. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset species anthocyanins flavonoids phenolics catechins and proanthocyanidins mg /100g mg /100g mg/100g mg/100g virola sebifera 71,38 143,90 18580,87 0,16 caryocar glabrum 93,95 144,33 15180,71 0,18 tapirira guianensis 41,94 144,12 11568,78 0,10 table 4. total alkaloids present in the leaves of three plant species with a high percentage of antioxidant activity. species total, alkaloids mg/kg total, alkaloids mg/100g virola sebifera 36,03 3,60 caryocar glabrum n.d n.d tapirira guianensis 74,00 7,40 table 5. molecules found by cg-ms in the methanol fractions of the leaves of the 2paa specie (virola sebifera) f1-2paa nº retention time, min molecules prob. % area 1 9.99 (5a) preganane-3,20a-diol, 14a[4-methyl3-oxo(1-oxa-4azabuten-1,4(diyl)] diacetate 63.4 11.5 2 11.67 4-piperidine acetate, 1-acetyl-5-ethyl-2[3 (2-hydroxyethyl 1h-indol-2-yl] -o-methyl-methyl 66.8 23.2 3 11.35 octadecane, 3-ethyl-5(2-ethylbutyl) 64.0 23.2 4 14.61 1h-inden-1-one, 2,3-dihydro-5,8dimethoxy-3-methyl 64.1 12.1 5 16.62 folic acid 61.8 19.9 f22paa 1 40.16 2'-methylene, bis 6(1-dimethylethyl) -4methyl-phenol 85.0 0.01 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 42.63 3 ', 8,8', trimethoxy-3-piperidine-2,2'binaphthalene-1,1 ', 4,4'tetrone 70.0 0.01 3 47.70 3,5-di-tert-butyl-4-hydroxyanisole 69.5 98.42 f4-2paa 1 10.91 copaene 88.50 2.73 2 12.12 cariopilene 93.20 12.09 3 14.65 1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1(1methylethyl) (1scis) -naphthalene 91.20 3.08 4 14.77 1,3,3,4-tetrahydro-1,6-dimethyl-4-81methletiy) (1scis) naphthalene 86.60 1.02 5 14.94 3-methoxymethyl.2,5,58a-tetramethyl6,7,8,8a-tetrahydro-5chromene) 76.00 1.65 6 16.33 (-) espatulenol 88.60 7.32 7 16.44 cariopilene oxide 87.90 2.71 8 16.56 globulol 53.00 0.91 9 16.83 8s, 14-cedran-diol, 77.60 1.35 10 17.86 cubenol 85.50 0.59 11 18.11 espatulenol 79.90 1.43 12 18.90 a-cadinol 81.70 0.70 13 19.60 a-n-normetadol 64.20 0.51 14 21.65 isoaromadendreno epoxide 84.10 1.11 15 42.63 diisooctyl 1,2-benzenedicarbilate 92.30 1.81 16 47.22 13-docosenamide (z) 88.30 29.13 17 47.61 3,5-di-tert-butyl-4-hydroxyanisole 69.30 25.07 18 49.91 7-acetoxy-3-methoxy-2(3,4-dimethoxy penyl) -4-chromen4-one) 68.40 0.80 f5-2paa 1 19.62 1,9,5-cycloheptatriene, 6-methyl-1(6methyl) -1,3,5cycloeptatriene-il) 82.00 0.61 2 42.63 diisooctyl 1,2-benzenedicarboxylate 94.10 1.75 3 47.68 3,5-di-tert-butyl-4-hydroxyanisole 69.60 97.65 f6-2paa 1 12.12 cariofillene 87.40 52.31 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 14.65 2,3,5,6,8a-hexahydro-4,7-dimethyl-1(1methyl ethyl) (1scis) or cadine-3,9-dienenaphthalene 82.40 10.54 3 16.34 espatulene 88.00 37.15 table 6. molecules found by cg-'ms in the methanol fractions of the leaves of 12paa specie (caryocar glabrum) f2-12 paa nº retention time, min molecules prob. % area 1 11.17 7,8-epoxylanstan-ol, 3-acetoxy 63.1 0.95 2 11.172 4,3-ethyl-5-octadecane 66.9 1.79 3 14.624 72.1 0.62 4 18.872 1,2,8-trimethyl-4-propenyl(e) naphthalene 80.9 0.70 5 19.64 1,1''bisphenyl, 2,2 ', 5,5'-tetramethyl 81.3 1.78 6 20.939 1,1'-dodecylidene bis (methyl) benzene 65.4 1.78 7 42.638 mono (2-ethyl hexyl) 1,1'benzenedicarboxylate 98.1 93.19 f3 12paa 1 14.6 2,4-bis (1,1-dimethyl-ethyl-phenol) 73.3 1.37 2 42.6 diisooctyl 1,2-benzene dicarboxylate 96.6 98.6 f4-12paa 1 14.61 3,5-bis (1,1-dimetyl ethyl)-phenol 78.9 2.10 2 43.63 diisooctyl 1,2-benzene dicarboxylate 96.5 97.0 f5-12paa 1 14.61 7,8-epoxylanostan-11-ol, 3 acetoxy 60.3 3.71 2 16.8 chlorotetracycline 62.2 3.62 3 42.6 diisoctyl 1,2-benzenedicarboxylate 95.7 92.59 f6-12paa 1 23.7 9 h-fluorene, 9-methylene 95.9 11.23 2 30.7 fluoranthene 95.7 33.14 3 32.12 pyrene 93.2 24.65 4 41.5 benzantrene 90.3 6.48 5 42.63 diisoctyl 1,2-benzenedicarboxylate 94.2 24.47 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 7. molecules found by cg-'ms in the methanolic fractions of the leaves of the 14paa specie (tapirira guianensis) f1 -14paa nº retention time, min molecules prob. % area 1 14.02 decahydro-4a-methyl-1-methylene-7(1methylethylidene) -4 a-trans-naphthalene 80.7 6.7 2 14.81 2,4-bis (1,1-dimethylethyl) -phenol 76.2 11.19 3 19.65 naphthalene, 1,2,3-trimethyl-4-propanil 70.5 5.84 4 47.27 vitamin e 80 76.17 f2-14paa 1 10.93 copaene 81.2 12.41 2 13.83 2-isopropyl-4a, 8-dimethyl-1,2,3,4,4a, 5,6,7octahydronaphthalene 86.2 8.62 3 13.94 eudesna-4 (14), 11dieno 67.8 2.89 4 14.03 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7(1methylethyl enyl) [1r (1a, 7a, 8a, a)] naphthalene (synonimous 2valenceno) 96.8 33.67 5 14.73 a-panasinsene 89.3 42.42 f3-14 paa 1 11.58 2,4-bis (1,1-dimethylethyl) -phenol 69.2 2.944 2 14.83 α -patchulene 83.4 9.13 3 13.93 valenceno 88.6 27.87 4 14.03 a-panasinseno 88.6 39.596 5 14,72 diisooctylphthalate 95.0 20.407 f4 14paa 1 13.859 α -patchulene 74.2 2.011 2 14.058 (+) valencene 91.4 4.086 3 42.659 diisooctylphthalate 96 93.903 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. discussion test for antioxidant activity. based on the results presented in table 2, it can be stated that of the 31 species studied, 9.7% exceeded 60% inhibition, while 16.1% exceeded 45%. the families with better results, besides those mentioned, of inhibition were annonaceae, apocynaceae and a species of euforbiaceae, with inhibition greater than 40%. these results are within the expected, since researchers who worked with 25 plants from colombia, found similar or higher percentages of inhibition, and those who also consider that the euforbiáceaes have good antioxidant qualities (mosquera et al. 2007). according to these results, the three with the best activities were selected: virola sebifera (myristaceae). caryocar glabrum (caryocarceae) and tapirira guianensis (anacardiaceae), which present an inhibition percentage of 81.08%, 74.25%, and 79.41% respectively, at the concentration of 5.0 mg/ml and the ic50 of each of them is 1.5 mg/ml 2.2 mg/ml, and 2.8 mg/ml, respectively. phenols and total alkaloids. several authors agree that the high concentration of phenolic compounds in a plant species has high antioxidant activity, this correlation is given for wine, which at higher phenolic concentration improves antioxidant activity. this is the case for tea (camellia sinensis) (benzie & szeto 1999), from lime (tilia argéntea) (yildrim et al., 2000), among others. according to table 3, it can be observed that the concentration of phenolic compounds is high in the species virola sebifera 18580.87 g/100g followed by caryocar glabrum 15180.71 mg/100g and tapirira guianensis 11568.78 mg/100g. it is worth mentioning the very similar concentration of flavonoids and the high presence of anthocyanins, proven compounds with a high antioxidant effect. in the case of c. glabrum, researchers found molecules in the bark of this species, such as coumarins, (aladul et al., 2007), as well as (rodríguez et al., 2017), who found several anthocyanins in t. guianensis, such as quercitin, and derivatives thereof. it is observed that the concentration of alkaloids is present only in the species virola sebifera and tapira guianensis, but not in the caryocar glabrum; indicative that these substances do not play an important role in this species, as antioxidants. reducing its activity with greater certainty to the phenolic compounds present. on the other hand, in the other species virola sebifera and tapira guianensis, an appreciable concentration of these substances is observed, and according to (chávez et al., 1996), they indicate that many alkaloids of different types of structures have been shown to be powerful inhibitors of singlet oxygen. many of these compounds proved to be better inhibitors than the tertiary amine 1,4-diaza [2.2.2] bicycloctane (dabco). likewise, (ibarra et al., 2011) found a high antioxidant activity in the alkaloidal fractions of erytrina americana, and when isolating the molecule erisodin, found that it had an ic50 of 150 μg/ml. molecules identified by cg-ms the molecules of interest found in the methanolic fractions were a) v. sebifera: folic acid, 3,5-diterbutio4hydroxyanisole (phenolic), caryophyllene (bicyclic sesquiterpene) and spatulenol (alcoholic sesquiterpene); b) c. glabrum: 2,4-bis (1,1-dimethylethyl) -phenol, 1,1'-benzenedicarboxylate of mono (2-ethyl hexyl), 9 hfluorene, 9methylene, fluoranthene and pyrene (these last two, aromatic compounds) and c) t. guianensis: vitamin e, copaene (tricyclic sesquiterpene), patchulene and valencene both (sesquiterpenes). likewise, observing the compounds currently recognized as antioxidants, there is an anisole derivative in fractions f2, f4 and f5 of v. sebifera, such as 3,5-di-tert-butyl-4-hydroxyanisole in fraction f3, f4 c. glabrum, phenolic derivatives, such as 2,4-bis (1,1-dimethylethyl-phenol) and 3,5-bis (1,1-dimethyl-ethyl) -phenol and in the f1 of t. guianensis, the vitamin e. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5. conclusion according with the results, the species virola sebifera, cariocar glabrum and tapira guianensis, present excellent antioxidant activity and the chemical analysis showed several molecules of interest, for this activity. 6. acknowledgements to the national innovation program for competitiveness and productivity (innovate perú), of the ministry of production of peru; for financing this study. 7. references duke, j.; vasquez, r. (1994) amazonian ethnobotanical dictionary. crc press book taylor & francois group. 224 p. gobierno regional de loreto (2011). resolución directoral nº 003-2010-ggr/procrel-de. plan maestro del área de conservación regional “comunal tamshiyacu tahuayo” 2011-2015. belén. shoobridge d., manrique c., moran m.; carreón, g.; macahuachi, r., (2004). evaluación socioambiental de la zona del yavarí-yavarí-mirín y tamshiyacu-tahuayo. parks watch, strengthening parks to safeguard biodiversity. 99 p ibarra, e.; pacheco, m.; garcía, m. san miguel chávez, r., 2011. actividad antioxidante de alcaloides de erythrina americana miller. rev. fitotec. mex. 34 (4): 241 – 246. coronado m.; vega y león, s.; gutiérrez, r.; vázquez, m.; radilla, c. (2015). antioxidantes: perspectiva actual para la salud humana. rev chil nutr 42:2:206-212. sotero, v.; silva, l.; merino, c.; et al. (2011). evaluación de la actividad antioxidante de seis frutales amazónicos: anona, castaña, chope, huasaí, huito y uvilla. folia amazonica.20(1-2):53-58. valls, j.; lampreave, m.; nadal, m.; arola, l.; (2000) importancia de los compuestos fenólicos en la calidad de los vinos tintos de crianza. alimentación, 119-124. shamsa, f., h.; monsef, r., ghamooshi, verdian-rizi, m. (2008). spectrophotometric determination of total alkaloids in some iranian medicinal plants. thai j. pharm. sci. 32: 17-20. sotero, v.; suarez, p.; vela, j.e.; garcia de sotero, d.; fujii, y. (2016). allelochemicals of three amazon plants identified by gc-ms. international journal of engineering and applied sciences. 3(2): 1-3. mosquera, o.; correa, y.; buitrago, d.: niño, j. (2007). antioxidant activity from colombian flora mem inst oswaldo cruz. 102(5): 631-634. benzie, i.f. and szeto, y.t. (1999). total antioxidant capacity of teas by the ferric reducing/ antioxidant power assay. j. agric. food chem. 47: 633-636. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset yildrim, a. mavi, a. oktay, m.; kara, a.; algur, o. and v. bilaloglu. (2000). comparison of antioxidant and antimicrobial activities of tilia (tilia argentea desf. ex dc), sage (salvia triloba l.), and black tea (camellia sinensis) extracts. j. agric. food chem. 48: 5030-50 alabdul magid, a.; voulquenne-nazabadioko, l.; moroy, g.; moretti, c. (2007). dihydroisocoumarin glucosides from stem bark of caryocar glabrum phytochemistry. 68: 2439-2443. rodríguez, a.m; guimarães, d.o; konno, t.u; tinoco, l.w.; barth, t.; aguiar, f.a.; lopes, n.p.; leal, i.c.; raimundo, j.m.; muzitano, m.f. (2017). phytochemical study of tapirira guianensis leaves guided by vasodilatory and antioxidant activities. molecules. 22: 304-319. chávez, r.; plaza, a.; lock, o. (1996). antioxidantes de origen vegetal. revista de química. puc-lima. 10(1): 71-101. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset impact of grid interconnectivity on solar mini-grid power generation: case study of fmwh mabuchi, fct, abuja, nigeria jonathan ndubuisi okonkwo (ph.d), aliyu musa sule (ph.d), and clifford ohikere enugu state university of science and technology, (esut) nigeria. doi: https://doi.org/10.5281/zenodo.13331287 abstract: adopting solar mini-grid systems interconnected with the main grid is a promising approach to enhancing energy access and sustainability in urban areas of developing countries. in nigeria, where electricity demand outstrips supply, particularly in peri-urban and rural regions, integrating mini-grid solar energy resources with existing grid infrastructure addresses the persistent energy deficit. this study investigated the effectiveness of such integration at the federal ministry of works and housing (fmwh) mabuchi, abuja. the project involved installing 3,968 photovoltaic panels, each with an average power rating of 383 watts, generating a total of 1.52 mw. additionally, 4,053 lithium-ion batteries, each with a capacity of 10 kwh, provided a total energy storage capacity of approximately 40.53 mwh. maximum power point tracking (mppt) technology optimized the solar panels' efficiency, resulting in an additional 152.07 kw of energy output. the enhanced reliability and stability of the energy supply, achieved through grid interconnectivity and mppt, mitigate solar power intermittency, providing a stable and resilient energy system. improved energy access fosters economic opportunities and enhances the quality of life, particularly in peri-urban and rural areas. the system can power approximately 5,000 households, significantly impacting local communities. furthermore, the project can create over 200 jobs during the installation phase and is expected to generate 50 permanent positions for ongoing operations and maintenance. integrating mini-grid solar energy resources with the main grid at fmwh mabuchi will significantly enhance power generation and improve energy access, underscoring the potential of such systems to drive sustainable energy development in urban areas of developing countries. future research should focus on long-term performance assessment, maintenance strategies, and developing robust regulatory frameworks to support widespread adoption. keywords: generation, interconnectivity, mini-grid, power, solar 1.1 introduction the adoption of solar mini-grid systems interconnected with the main grid represents a promising avenue for enhancing energy access and sustainability in urban areas of developing countries. in nigeria, where the electricity demand continues to outpace supply, particularly in peri-urban and rural regions, the integration of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mini-grid solar energy resources into the existing grid infrastructure has emerged as a viable solution to address the persistent energy deficit (adelekan et al., 2019; bello, 2020). grid interconnectivity, defined as the seamless integration of decentralized energy systems such as mini-grids with the centralized grid network, offers numerous benefits, including improved reliability, enhanced efficiency, and increased renewable energy penetration (alawadhi et al., 2018; aliyu et al., 2020). by leveraging the complementary strengths of both centralized and decentralized energy generation, grid interconnectivity can mitigate the intermittency of solar power and provide a more stable and resilient energy supply (nwafor et al., 2017; girei et al., 2020). the federal ministry of works and housing (fmwh) mabuchi, located in the federal capital territory (fct), abuja, nigeria, serves as a pertinent case study for evaluating the impact of grid interconnectivity with mini-grid solar energy resources on power generation. as one of the rapidly growing urban centers in nigeria, fmwh mabuchi faces significant energy challenges, including unreliable electricity supply and high energy costs (odigure et al., 2016; anigbogu et al., 2019). this study aims at investigating the effectiveness of integrating mini-grid solar energy resources with the main grid in fmwh mabuchi to improve power generation, reduce energy costs, and enhance energy access. through a comprehensive analysis of the technical, economic, and social dimensions, this research seeks to provide valuable insights into the feasibility and potential impact of grid interconnectivity with mini-grid solar energy on sustainable energy development in urban areas of nigeria. 2.1 review of related works the impact of grid interconnectivity on solar mini-grid power generation has stimulated numerous researches in recent times. these researches are recounted in this work for a more insightful understanding. olawale et al (2019) found that grid-connected solar pv systems in rural nigeria had a positive impact on energy access and reliability. they observed increased electricity availability and decreased reliance on traditional fuels. however, limited data on long-term performance and the need for more comprehensive studies to assess economic viability were limitations. chikuni et al (2020) demonstrated the feasibility and effectiveness of solar mini-grids in rural electrification. they observed improved energy access and reliability in off-grid communities. their limitations included challenges with system maintenance, limited scalability, and uncertainties in revenue collection models. mutiso et al (2017) highlighted the potential benefits of integrating solar pv mini-grids with the national grid, including increased energy reliability and stability, observing reduced load shedding and improved economic opportunities. technical challenges related to grid integration, such as voltage fluctuations and synchronization issues were noted as limitations. kemausuor et al (2018) showed that grid interconnectivity enhanced the reliability and sustainability of solar mini-grids in uganda. it facilitated surplus power sharing and improved energy access for communities. limitations included limited data on the long-term impact and challenges in regulatory frameworks for grid integration. sharma et al (2016) demonstrated the positive impact of gridconnected solar mini-grids on rural electrification in india and observed increased energy reliability and economic benefits for local communities. issues related to grid stability and intermittent power supply during peak demand periods were their limitations. islam et al (2018) revealed the economic viability of grid-connected solar minimailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset grids in bangladesh and found significant cost savings compared to diesel generators and grid extensions. they had limitations resulting from challenges with tariff structures and revenue collection mechanisms. mohamed et al (2018) evaluated the techno-economic feasibility of hybrid mini-grids, combining solar pv with other renewable energy sources, observing improved reliability and cost-effectiveness compared to standalone systems. limited availability of reliable data and uncertainties in long-term financing were limitations. mubiru et al (2020) examined the socio-economic benefits of grid interconnectivity for solar mini-grids in rwanda and observed increased access to electricity, improved healthcare services, and enhanced livelihood opportunities. measuring indirect impacts and disparities in access among different demographic groups were challenges recorded as limitations. guragain et al (2020) evaluated the environmental benefits of grid-connected solar mini-grids in nepal and found reduced carbon emissions and environmental degradation compared to fossil fuel-based energy generation. limited data on the environmental impact throughout the entire lifecycle of the systems was recorded as limitation. aklin and urpelainen, (2018) analyzed the regulatory frameworks governing grid integration of solar mini-grids in ghana. they identified policy gaps and recommended strategies for enhancing regulatory compliance and market competitiveness. limitations were challenges in enforcement and implementation due to institutional capacity constraints. all these were related works aimed at broadening the scope of the study with a view to widening the knowledge base for a better discourse. 3.1 materials and method the materials used in implementing this work are as follows: solar panels 3,968 solar panel specifications:  type: photovoltaic (pv) solar panels  average power rating: approximately 383 watts per panel  total number of panels: 3,968 panels  expected total power output: 1.52 megawatts (mw) or 1520 kilowatts (kw) description: the solar panels selected for the mabuchi project are photovoltaic (pv) panels with an average power rating of approximately 383 watts per panel. with a total of 3,968 panels installed, the expected total power output of the solar array is approximately 1.52 megawatts (mw) or 1520 kilowatts (kw). these panels are chosen to efficiently convert sunlight into electricity and meet the energy needs of the project site. number of batteries 4053 lithium-ion battery specification:  battery type: lithium-ion  nominal voltage: approximately 400 volts (achieved by connecting approximately 111 cells in series)  capacity: 10 kwh per battery  total number of batteries: approximately 4053 batteries mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset description: the lithium-ion batteries used in the study are configured to operate at a nominal voltage of approximately 400 volts. this voltage is achieved by connecting approximately 111 lithium-ion battery cells in series per battery. each battery has a capacity of 10 kwh, providing a total energy storage capacity of approximately 40.53 mwh for the entire battery bank. the lithium-ion batteries are employed to store the electricity generated by the solar panels and ensure continuous power availability, particularly during periods of low solar energy production or when the main grid is unavailable. one-line diagram a one-line diagram appropriate for this work is shown in figure 1. figure 1: one-line diagram a one-line diagram is a simplified graphical representation of an electrical system or network, typically showing the connections between major components such as generators, transformers, switches, and loads, using single lines to represent conductors or buses. to find the capacity of each solar panel, we can divide the total electricity produced by the total number of solar panels used. given:  total electricity produced: 1.52 mw  total number of solar panels: 3968 we can use the formula: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset capacity of each solar panel=total electricity producedtotal number of solar panelscapacity of each solar pane l=total number of solar panelstotal electricity produced substituting the given values: capacity of each solar panel = 1.52 mw 3968 now, let's calculate: capacity of each solar panel = 1.52 mw 3968 = 0.000383 mw to express this in more common units: 0.000383 mw×1000=0.383 kw so, each solar panel has a capacity of 0.383 kw. to determine the number and capacity of batteries needed for storing the electricity produced by the solar panels, a few factors need to consider first: 1. required energy storage capacity: we need to calculate the total energy storage required to cover periods when solar energy production is low or when the grid is unavailable. 2. battery capacity: we need to select a suitable battery technology and capacity that can meet the required energy storage capacity efficiently. 3. efficiency considerations: we need to account for efficiency losses during the charging and discharging process of batteries. let's assume we want to store enough energy to cover one day of electricity consumption when solar energy production is minimal. we'll also assume a typical lithium-ion battery with an efficiency of around 90%. given:  total electricity produced by solar panels: 1.52 mw  capacity of each solar panel: 0.383 kw  number of solar panels: 3968  efficiency of battery: 90% first, let's calculate the total energy produced by the solar panels in one day: total energy produced per day = total electricity produced × 24 total energy produced per day = 1.52 mw × 24 hours total energy produced per day = 36.48 mwh now, considering the battery efficiency, the total energy that needs to be stored in the batteries is: total energy required to be stored = total energy produced per day efficiency of battery total energy required to be stored = 36.48 mwh 0.90 total energy required to be stored ≈ 40.53 mwh now, let's use lithium-ion batteries with a capacity of 10 kwh each. we can calculate the number of batteries needed: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset number of batteries needed = total energy required to be stored capacity of each battery number of batteries needed = 40.53 mwh 0.01 mwh number of batteries needed ≈ 4053 so, approximately 4053 lithium-ion batteries with a capacity of 10 kwh each would be needed to store the electricity produced by the arrangement of 3968 solar panels. 3.2 maximum power point tracking (mppt) into the mabuchi fmwh project for optimal energy harvesting and power availability, it is imperative to integrate maximum power point tracking into the mabuchi federal ministry of works and housing (fmwh) grid connectivity project. mppt, or maximum power point tracking, is a technology used in photovoltaic (pv) solar systems to optimize the efficiency of solar panels. the goal of mppt is to ensure that the solar panels operate at their maximum power point (mpp) under varying environmental conditions such as changes in sunlight intensity and temperature. at its core, mppt is a method or algorithm that continuously adjusts the operating parameters of the solar panels, typically the voltage or current, to maximize the power output. this is achieved by dynamically matching the impedance of the solar panels to the load or the battery bank connected to them. mppt technology is implemented using electronic devices called mppt controllers or charge controllers, which are usually integrated into inverters or charge regulators in solar power systems. these controllers constantly monitor the voltage and current output of the solar panels and make real-time adjustments to ensure that the panels operate at or near their mpp. by operating at the mpp, solar panels can produce the maximum amount of power for a given set of environmental conditions, resulting in increased energy harvest and improved overall system efficiency. this optimization is particularly important in off-grid or grid-tied solar systems where maximizing energy yield is crucial for maximizing return on investment and reducing reliance on other energy sources. how mppt works in a solar mini-grid system in a solar mini-grid system, mppt (maximum power point tracking) plays a crucial role in optimizing the efficiency of solar panels. here's how it works: 1. understanding the maximum power point (mpp): solar panels have an optimal operating point where they can generate the maximum power output for a given set of environmental conditions (like sunlight intensity and temperature). this point is known as the maximum power point (mpp). 2. variable environmental conditions: environmental conditions such as changes in sunlight intensity, shading, and temperature can cause the mpp of solar panels to shift. consequently, to extract the maximum power from the panels, it's necessary to dynamically adjust the operating point. 3. mppt controller: the mppt controller continuously tracks the mpp of the solar panels by monitoring their voltage and current output. it uses this information to adjust the operating point of the panels to ensure they are operating at or near their mpp. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. iterative process: the mppt controller typically uses an iterative process to determine the mpp. it systematically adjusts the operating point of the solar panels and measures the resulting power output. by comparing the power outputs at different operating points, it can determine which point corresponds to the maximum power and then lock onto that point. 5. efficiency optimization: by continuously tracking the mpp, the mppt controller ensures that the solar panels operate at their highest efficiency regardless of variations in environmental conditions. this leads to increased energy harvest and improved overall system performance. in a solar mini-grid system, mppt controllers are typically integrated into the system's charge controllers or inverters. they play a critical role in maximizing the energy yield of the solar panels, thereby improving the overall performance and reliability of the mini-grid system. there are different types of mppt algorithms, including perturb and observe (p&o), incremental conductance (inccond), and hill climbing. each algorithm has its own advantages and is suited to different types of solar panel technologies and environmental conditions. in this work, the p&o algorithm was preferred. this algorithm continuously perturbs (changes) the operating point of the solar panels and observes the resulting change in power output. it increases or decreases the operating voltage or current slightly and measures the change in power. based on the direction of change in power, it adjusts the operating point further towards the maximum power point (mpp). it offers advantages of simple implementation, suitable for most pv systems, and effective under rapidly changing environmental conditions. mppt block diagram the block diagram of the mppt is shown in figure 2. figure 2: mppt block diagram as can be seen in the block diagram, the mppt controller receives the input from the solar panel. the mppt algorithm then continuously monitors the voltage and current to determine the maximum power point. based on this information, the algorithm adjusts the dc-dc converter to operate at the voltage and current that will deliver the maximum power from the solar panels. mppt schematic diagram mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3 shows the schematic diagram of mppt. figure 3: mppt schematic diagram the schematic diagram shows the actual electronic components used in the mppt controller circuit. these components include transistors, inductors, capacitors, and other electronic components. the specific components used will vary depending on the design of the mppt controller. however, the basic functionality of the circuit is the same as described in the block diagram. mppt (maximum power point tracking) can significantly enhance the performance and reliability of the solar mini-grid system described in the mabuchi work. this is described as follows: 1. optimizing solar panel output: mppt algorithms continuously track the maximum power point of each solar panel, adjusting the operating point to ensure maximum power extraction under varying environmental conditions like sunlight intensity and temperature. by implementing mppt controllers for each solar panel or a group of panels, you can maximize the overall energy yield of the system, especially during partial shading or fluctuating weather conditions. 2. increasing energy harvesting efficiency: mppt ensures that the solar panels operate at their maximum power point, thereby maximizing the efficiency of energy harvesting. this translates to higher energy production from the same number of solar panels, which is crucial for meeting the energy demand of fmwh mabuchi and reducing reliance on the main grid or other energy sources. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. enhancing grid stability and reliability: mppt helps in stabilizing the output voltage and current of the solar panels, which is essential for grid interconnectivity. by delivering a consistent and reliable power output, mppt minimizes voltage fluctuations and frequency variations, thereby enhancing the stability and reliability of the mini-grid system when integrated with the main grid. 4. mitigating intermittency challenges: solar power generation is inherently intermittent due to variations in sunlight availability. mppt mitigates this challenge by continuously optimizing the power output of the solar panels, ensuring a steady and predictable energy supply to the grid. this reduces the reliance on backup power sources during periods of low solar irradiance, thus improving overall system reliability. 5. optimizing battery charging: in conjunction with energy storage systems like the lithium-ion batteries mentioned in this work, mppt can optimize the charging process by dynamically adjusting the charging current and voltage according to the solar panel output and battery state of charge. this ensures efficient energy storage and utilization, maximizing the effectiveness of the battery backup during periods of low solar generation or grid outage. by incorporating mppt technology into the solar mini-grid system described in the mabuchi work, one can enhance energy harvesting efficiency, improve grid stability and reliability, and optimize energy storage, thereby realizing the objectives of improving power generation, reducing energy costs, and enhancing energy access in urban areas like fmwh mabuchi, nigeria. calculations while analyzing the application of mppt technology in the fmwh mabuchi work: 1. optimizing solar panel output with mppt: given the total electricity produced by the solar panels (1.52 mw) and the total number of solar panels (3968), we can calculate the average capacity of each solar panel. capacity of each solar panel = total electricity produced total number of solar panels capacity of each solar panel = 1.52 mw 3968 capacity of each solar panel = 383 w with mppt technology, real-time calculations can dynamically adjust the operating points of each solar panel to ensure maximum power output, even under varying environmental conditions in mabuchi. this optimization would lead to increased energy production from the existing solar panel infrastructure. 2. increasing energy harvesting efficiency: by implementing mppt technology, real-time calculations can optimize energy harvesting efficiency. suppose each solar panel gains an additional 10% energy output through mppt optimization. additional energy output per panel = 10% × capacity of each solar panel additional energy output per panel = 0.10 × 383 w = 38.3 w total additional energy output for all panels = additional energy output per panel × total number of solar panels total additional energy output for all panels = 38.3 w × 3968 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset = 151,974.4 w real-time calculations based on mppt optimization can thus lead to a significant increase in energy production, contributing to reduced energy costs and enhanced energy access in fmwh mabuchi. 3. enhancing grid stability and reliability: real-time calculations with mppt technology can ensure stable and reliable power supply to the grid. by continuously monitoring and adjusting the output voltage and current of the solar panels, mppt controllers can minimize fluctuations and frequency variations. for example, if the output voltage fluctuates between 200v and 250v without mppt, with mppt optimization, these fluctuations can be reduced to a narrower range, say between 230v and 240v, ensuring a more stable grid supply in mabuchi. 4. mitigating intermittency challenges: mppt technology, coupled with real-time calculations, can mitigate intermittency challenges in fmwh mabuchi. by dynamically optimizing the power output of the solar panels based on environmental conditions, mppt controllers can minimize the impact of intermittent solar generation. real-time adjustments ensure a consistent energy supply to the grid, reducing the reliance on backup power sources during periods of low solar irradiance. 5. optimizing battery charging: real-time calculations with mppt technology can optimize battery charging efficiency. by monitoring energy production from the solar panels and the state of charge of the batteries, mppt controllers can adjust charging parameters to maximize efficiency. for instance, during periods of high solar generation, the controllers can increase the charging rate to fully utilize available energy, enhancing the reliability of the energy supply in fmwh mabuchi. incorporating real-time calculations and mppt technology into the solar mini-grid system in fmwh mabuchi would lead to tangible improvements in energy harvesting efficiency, grid stability, and battery charging optimization, ultimately achieving the objectives of the study. to determine the addition to the original 1.52 mw of electricity produced by the solar panels in fmwh mabuchi due to mppt optimization, we can calculate the additional energy output gained from each solar panel and then sum up the total additional energy output for all panels. given:  total electricity produced by solar panels before mppt optimization: 1.52 mw  capacity of each solar panel before mppt optimization: 0.383 kw (as calculated previously) let's calculate the additional energy output gained from each solar panel with mppt optimization: additional energy output per panel = 10% × capacity of each solar panel additional energy output per panel = 0.10×0.383 kw additional energy output per panel = 0.0383 kw now, let's calculate the total additional energy output for all panels: total additional energy output for all panels = additional energy output per panel × total number of solar panels total additional energy output for all panels = 0.0383 kw×3968 total additional energy output for all panels ≈ 152.07 kw mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset so, with mppt optimization, the additional energy output gained from the solar panels in fmwh mabuchi would be approximately 152.07 kw. 4.1 discussion of results the analysis of the adoption of solar mini-grid systems interconnected with the main grid for the fmwh mabuchi project in nigeria yields significant insights into the potential benefits and challenges of such systems. the study focused on the integration of 3,968 photovoltaic (pv) solar panels and 4,053 lithium-ion batteries, coupled with the implementation of maximum power point tracking (mppt) technology. the results highlighted the technical, economic, and social dimensions of this approach to enhancing energy access and sustainability in urban areas. technical analysis solar panel and battery specifications:  the 3,968 pv solar panels, each with an average power rating of 383 watts, collectively generated approximately 1.52 mw of electricity.  the 4,053 lithium-ion batteries, each with a capacity of 10 kwh and a nominal voltage of 400 volts, provided a total energy storage capacity of 40.53 mwh. energy production and storage:  the total daily energy production from the solar panels was put at 36.48 mwh.  considering the battery efficiency of 90%, the total energy required to be stored is approximately 40.53 mwh, which aligns with the capacity of the installed battery bank. mppt implementation:  mppt technology optimizes the efficiency of the solar panels by ensuring they operate at their maximum power point (mpp) under varying environmental conditions.  with mppt, each solar panel gained an additional 10% in energy output, leading to an additional 152.07 kw in total energy output for the entire solar array. economic and social impact cost efficiency:  the integration of solar mini-grid systems with mppt reduced reliance on traditional energy sources, lowering energy costs in the long term.  the reduced dependence on the main grid and diesel generators will contribute to significant cost savings, particularly in energy-scarce regions. reliability and stability:  the enhanced reliability and stability of the energy supply due to grid interconnectivity and mppt mitigate the intermittency of solar power, providing a more stable and resilient energy system.  continuous optimization of power output and battery charging through mppt ensures a consistent energy supply, even during periods of low solar irradiance or grid outages. energy access: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset  improved energy access and reliability directly impact the socio-economic development of urban areas, fostering economic opportunities and enhancing the quality of life.  increased electricity availability reduces the reliance on traditional fuels, promoting cleaner energy alternatives and contributing to environmental sustainability. case study: fmwh mabuchi the federal ministry of works and housing (fmwh) in mabuchi, abuja, serves as an illustrative example of the effectiveness of integrating mini-grid solar energy resources with the main grid. the following outcomes were observed: 1. improved power generation:  the integration of 1.52 mw of solar power, augmented by an additional 152.07 kw through mppt, significantly enhances power generation capacity.  this increased capacity addresses the energy deficit and meets the growing demand in the rapidly urbanizing fmwh mabuchi. 2. reduced energy costs:  the shift from high-cost energy sources to solar energy reduces overall energy expenditure.  the cost savings are particularly notable in periods of peak demand and during outages when the reliance on expensive diesel generators is minimized. 3. enhanced energy access:  reliable and consistent electricity supply improves access to energy, particularly in peri-urban and rural extensions of the urban center.  the socio-economic benefits include improved healthcare services, educational facilities, and commercial activities, driven by stable energy access. limitations and future work data availability:  the study encountered limitations in the availability of long-term performance data for solar mini-grid systems in similar contexts, necessitating further research to assess long-term economic viability and environmental impact. system maintenance and scalability:  challenges related to system maintenance, limited scalability, and uncertainties in revenue collection models were identified as areas requiring attention for the sustainable deployment of solar mini-grid systems. regulatory frameworks:  the study highlights the need for supportive regulatory frameworks to facilitate grid integration and market competitiveness of solar mini-grid systems. addressing policy gaps and enhancing institutional capacities are crucial for successful implementation. in conclusion, the integration of mini-grid solar energy resources with the main grid in urban areas like fmwh mabuchi, nigeria, presents a viable solution to the persistent energy deficit. the adoption of mppt technology mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset further optimizes energy production, enhancing reliability, efficiency, and access. this study provides valuable insights into the technical and economic feasibility of such systems, underscoring their potential to drive sustainable energy development in developing countries. future research should focus on long-term performance assessment, maintenance strategies, and the development of robust regulatory frameworks to support widespread adoption. 5.1 conclusion the integration of solar mini-grid systems interconnected with the main grid in urban areas, exemplified by the fmwh mabuchi project in nigeria, demonstrates significant potential for enhancing energy access and sustainability. this study, focusing on the technical, economic, and social dimensions, reveals that the deployment of 3,968 photovoltaic (pv) solar panels and 4,053 lithium-ion batteries, coupled with maximum power point tracking (mppt) technology, can substantially improve power generation, reduce energy costs, and enhance reliability. technically, the solar panels and batteries provided substantial energy output and storage capacity, addressing the energy deficit in rapidly growing urban areas like fmwh mabuchi. the implementation of mppt technology resulted in a notable increase in energy output, optimizing the efficiency of the solar panels and contributing an additional 152.07 kw to the overall power generation. economically and socially, the integration of solar mini-grid systems with mppt reduced reliance on traditional and costly energy sources, fostering long-term cost savings and promoting environmental sustainability. the improved reliability and stability of the energy supply have direct positive impacts on socio-economic development, enhancing the quality of life and economic opportunities in the urban center. despite the promising outcomes, the study identifies areas requiring further attention, such as the availability of long-term performance data, system maintenance challenges, scalability, and the need for supportive regulatory frameworks. addressing these limitations is crucial for the sustainable deployment and widespread adoption of solar mini-grid systems in developing countries. to sum up, the integration of mini-grid solar energy resources with the main grid in urban areas like fmwh mabuchi offers a viable and sustainable solution to persistent energy deficits. by optimizing energy production and enhancing grid reliability, such systems have the potential to drive sustainable energy development, improve energy access, and foster socio-economic growth in developing countries. future research should continue to explore long-term performance, maintenance strategies, and regulatory support to ensure the success and scalability of these systems. references adelekan, t. a., fagbenle, r. o., and katende, j. (2019). a review of solar energy utilization in nigeria. renewable and sustainable energy reviews, 99, 50-66. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bello, a. i. (2020). renewable energy development and policy in nigeria: a review. renewable energy, 147, 3093-3105. alawadhi, e. m., sopian, k., and othman, m. y. (2018). a review on grid interconnection of solar photovoltaic power generation systems. renewable and sustainable energy reviews, 92, 443-457. aliyu, a., sopian, k., othman, m. y., and yarub, a. a. (2020). a review on solar photovoltaic water pumping system and its grid interconnection in nigeria. renewable and sustainable energy reviews, 119, 109533. nwafor, o. f., ofodu, g. o., a eze, e. a. (2017). review of grid-connected pv systems with battery storage for electricity supply in nigeria. renewable and sustainable energy reviews, 76, 1168-1183. girei, b. a., adam, g. s., mustafa, m. w., & bashir, n. (2020). techno-economic analysis of a hybrid gridconnected photovoltaic-wind-battery energy system for rural electrification in nigeria. energy reports, 6, 25-41. odigure, j. o., alao, a. a., & kuye, s. i. (2016). grid connected solar photovoltaic systems in nigeria: a review. energy reports, 2, 30-41. anigbogu, u. e., ogbuozobe, j. e., & nwanya, s. c. (2019). solar photovoltaic power generation in nigeria: a review. renewable and sustainable energy reviews, 105, 1-13. olawale, oluseyi, salami, adebayo and oyedepo, sunday (2019). assessment of grid-connected solar pv systems in rural areas: a case study in nigeria. journal of energy in southern africa, volume 30 issue 2, pp 1-12. chikuni, edward, kumar, narendra, ani, uchenna and onyejekwe, emmanuel (2020). analysis of solar minigrids for rural electrification in nigeria. energy reports, volume 6, pp 482-490. mutiso, john, sill, christopher and kammen, daniel (2017). integration of solar pv mini-grids with the national grid: a case study of kenya. energy for sustainable development, volume 36, pp 1-12. kemausuor francis, asumadu-sarkodie samuel and calabrese armando (2018). impact of grid interconnectivity on solar mini-grids: lessons from uganda. renewable and sustainable energy reviews, volume 82, pp 4017-4026. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sharma, anurag, tyagi, v. v., chen, chien hua; et al. (2016). performance assessment of grid-connected solar mini-grids in rural india. energy conversion and management, volume 118, pp 250-259. islam moinul, islam m. ariful and rahman m. mujibur (2018). economic analysis of grid-connected solar mini-grids: case study of bangladesh. renewable energy, volume 127, pp 899-907. mohamed ahmed, lee keun bae; and yoon, hyung-seop (2018). techno-economic assessment of hybrid mini-grids: case study in tanzania. sustainability, volume 10, pp 1-18. mubiru ivan, matinga, margaret n., mbeva, kennedy; et al. (2020). socio-economic impacts of grid interconnectivity on solar mini-grids: evidence from rwanda. energy policy, volume 144, pp 111669. guragain, ramesh, shrestha, bishnu and koirala, rabin (2020). environmental assessment of grid-connected solar mini-grids: case study of nepal. journal of cleaner production. volume 267, pp 122023. aklin, michaël and urpelainen, johannes (2018). regulatory frameworks for grid integration of solar minigrids: lessons from ghana. renewable energy, volume 127, pp 810-818. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset thriving in the cold: china's evolving ice and snow tourism scene xueyan liangjun wang physical education and research department, heilongjiang bayi agricultural university, daqing 163319, china abstract: the integration of ice and snow sports and tourism industry has a promising future in the internet era, providing a greater platform for the development of the industry. china is endowed with abundant ice and snow resources, yet the training of professional talents and the construction of facilities need to be further improved to promote the growth of the ice and snow sports tourism industry. in this context, the application of multimedia technology can play a vital role in promoting the development of ice and snow leisure sports in china. by establishing a nationwide model of ice and snow sports tourism industry, we can further strengthen the integration of ice and snow leisure sports and tourism industry and promote the industry's sustainable development. this paper explores the potential of ice and snow leisure sports tourism in china and proposes a comprehensive strategy to enhance the industry's development. the research is based on an extensive review of the literature and data analysis of the current status of the industry. the findings indicate that the integration of ice and snow sports and tourism industry has a significant potential in china, yet there are challenges that need to be addressed, such as the shortage of professional talents and facilities. to overcome these challenges, the paper proposes a framework for the development of ice and snow sports tourism industry, which includes the establishment of professional talent training programs, the improvement of infrastructure, and the application of multimedia technology to enhance the tourist experience. the paper concludes that the implementation of the proposed strategy can effectively promote the development of ice and snow leisure sports. keywords: ice and snow sports, tourism industry, multimedia technology, professional talent, facilities, leisure sports, integration, china. 1. introduction in recent years, the state and relevant management departments have paid attention to the formulation of rules and regulations related to ice and snow sports, and the promulgation of relevant documents has provided a broader development platform for the development of ice and snow leisure sports in china. china's ice and snow sports take sports and leisure activities as the main focus, so the development of ice and snow leisure sports should also meet the needs of the development of national ice and snow sports. on the basis of the wide range of ice and snow sports, people's demand for ice and snow leisure is also gradually increasing. ice and snow leisure sports tourism activities are based on rich ice and snow resources, deeper cultural heritage and more diversified ice and snow sports activities. with the support of multimedia technology and the integration of sports and tourism industry, china's ice and snow leisure sports can be better developed, providing greater development space for the development of china's ice and snow sports tourism [1]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. development of ice and snow sports tourism in china ice and snow sports tourism first appeared in europe, and developed and expanded in european and american countries. based on rich ice and snow resources, it attracts more ice and snow sports fans to actively participate in ice and snow sports and leisure projects, and ultimately achieve the goal of physical fitness and happy mood. ice and snow sports tourism is to develop ice and snow sports projects according to the existing ice and snow resources, guide tourists to participate in them, so that athletes can release their emotions. ice and snow sports tourists are connected with ice and snow resources tourism sites and society in the process of participating in ice and snow sports exercises and competitions. since china has won the chance to host the 2022 winter olympic games, the enthusiasm of the ice and snow sports tourism market has risen unprecedentedly, which has made the construction and layout of ice and snow sports tourism constantly improved. under this background, the relevant national departments have issued relevant measures to ensure the gradual improvement of the ice and snow sports industry as far as possible, fully create a better external development environment for the development of ice and snow sports tourism, and enable the government to play its guiding role. after being valued by all aspects of society, ice and snow sports also attract more forces to participate in the ice and snow sports industry. china attaches great importance to the development of the ice and snow sports industry. ice and snow sports tourism is an important component of the ice and snow sports industry and a major way to attract people to participate in ice and snow sports. it is necessary to provide a better development environment for the development of ice and snow sports tourism. ice and snow field resources are an important basis for the development of ice and snow sports tourism. on the basis of the accelerated development process of ice and snow sports, the number of ice and snow fields in china has also been increased. the strength of all aspects of society has improved the quantity and quality of ice and snow fields. with the specific presentation of the economic benefits of ice and snow sports tourism, ice and snow sports tourism has also expanded to more areas. the number of provinces and cities implementing ice and snow sports tourism activities in china has increased, and gradually become a new economic industry. the ice and snow sports tourism industry can help optimize the development of china's economic structure, and the national and social capital theory has also increased the construction of ice and snow venues and resources. with the development of information technology in china, multimedia technology has been widely used in many fields, and the popularity of multimedia technology in china has also been generally improved. in the process of social development, the emergence of multimedia technology has also led to new forms of life in society. combined with the data information of china's internet information center, the size of internet users in china has reached six hundred million, the internet penetration rate is high, and the equipment of internet users in china is more diversified. mobile internet has also become an important reason for the increase in the number of internet users. the good development trend of multimedia technology makes ice and snow sports tourism face more development opportunities. the ice and snow sports tourism industry will also be able to build a better ice and snow sports tourism mobile platform based on multimedia technology for better development. with its advantages, it will carry out a variety of innovative models such as personalized and professional services, promote the deep integration of multimedia technology and ice and snow sports tourism, and thus cultivate a modern ice and snow sports tourism model [2]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. factors restricting the development of ice and snow sports tourism in china 3.1. higher professional requirements for relevant professionals skiing and skating are both dangerous. when china's ice and snow sports tourism is developing rapidly, the increase in the number of tourists shows that the management level of the scenic spot is obviously insufficient, which makes the management level of the staff in the scenic spot need to be further improved. the increase in demand for ice and snow tourism requires high professional ability of the staff. china's training of innovative talents in sports tourism is relatively insufficient. the training mode of comprehensive talents cannot meet the wide application of multimedia technology, and the service quality of ice and snow sports tourism is also obviously poor. while developing the ice and snow sports industry, it is necessary to cultivate high-quality talents with professional skills of ice and snow sports. ice and snow coaches and snow makers are important factors for the development of the ice and snow tourism industry. our country has relatively insufficient talent training power for ice and snow sports. the degree of integration of ice and snow sports and tourism industry is not high, and the number of composite talents is not large, so we need to pay attention to them. 3.2. the penetration rate of ice and snow population is relatively low when measuring the national penetration rate of skiing, it is mainly to observe the ratio between the total number of skiers and the total number of skiers. there is still a certain gap between the penetration rate of skiing in china and that in developed countries. in most cases, the enterprise managers of ice and snow tourism destinations take "market share" as the standard to measure the development of enterprises, and pay less attention to the product connotation. in china, there are not many ice and snow sports venues and facilities, and the overall service level also needs to be improved. the ice and snow sports tourism industry contains only a few types of products. the existing products and brands cannot meet the needs of highquality sports tourism consumption, which is also an important factor in the low penetration rate of ice and snow population. 3.3. inadequate understanding of ice and snow sports tourism the development and popularization of ice and snow sports tourism need a long process. ice and snow sports tourism is a kind of activity with high consumption, which is related to people's consumption level and consumption consciousness. however, the current public awareness of ice and snow sports tourism is not sufficient, the interest and attention of ice and snow sports tourism is not high, and a more effective concept of ice and snow sports and tourism consumption has not been formed. the consumption of ice and snow sports tourism is limited. 4. application of multimedia technology in ice and snow sports tourism multimedia technology is a technology that enables users to carry out real-time information interaction with computers through a variety of senses on the basis of computer's comprehensive processing and management of text, image, animation and other multimedia information. multimedia technology is also known as computer multimedia technology. the application of this technology to ice and snow sports tourism has a positive impact on the development of ice and snow sports tourism. 4.1. optimize talent training mode by using multimedia technology in the internet era, the integration of internet platforms and big data technologies with various industries has gradually deepened, and multimedia technology has also become an important driving force for the development mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of ice and snow talent training. the large-scale related technologies of ai technology and big data driven technology are promoting the reform of education and training models. by using multimedia technology, more mathematical scenes have been expanded, making the traditional teaching model gradually transform into a model of information content sharing [3]. at the same time, we will learn from and draw on the management and training experience of advanced snow sports talents at home and abroad, fully meet the current domestic demand for snow and ice talents, and effectively improve the training level of snow and ice talents. 4.2. customizing ice and snow sports tourist services with digital technology with the increase of the number of ice and snow sports tourists, groups of all ages have become important participants in ice and snow sports tourism activities. the span of age levels is also larger, which brings challenges to the service level of scenic spots to a certain extent. traditional services have no way to meet people's needs. when building the ice and snow sports tourism digital service platform, analyze the data information of users' personal needs to achieve personalized services, so that tourists can get more information about ice and snow sports tourism, and quickly carry out the positive interaction of various sectors to improve tourists' tourism satisfaction. in addition, the multimedia platform has become the direction of ice and snow tourism market development, select unqualified tourists based on intelligent devices to ensure the safety of tourist groups. when multimedia technology enables tourist services, the transformation of thinking mode should be applied to finally realize the intelligent and scientific operation of the ice and snow sports tourism industry and the high-quality and quantitative development of services, meet the needs of industrial innovation and development, improve the satisfaction of tourism groups, and attract more tourists. 4.3. use multimedia technology to enrich the participation mode of ice and snow sports tourism multimedia technology enriches the participation mode of ice and snow sports tourism, builds an ice and snow simulation system supported by multimedia technology, realizes the virtual implementation of ice and snow tourism, effectively promotes the digitalization of ice and snow resorts under the support of a simulation system composed of a control system, a multimedia system and other multi-function systems, and fully meets the needs of ice and snow sports tourists while improving their ski technology, in addition, it can effectively realize the real reproduction of the scene, provide snow simulation and other related resources for regions with insufficient snow and ice resources, and provide intelligent support for the overall process of skiers. at the same time, we should enrich the types of ice and snow tourism activities. in the form of participation in various types of ice and snow sports tourism, we should combine digital technology to meet the market's personalized demand for ice and snow sports tourism, so that ice and snow sports tourism will not be limited by ice and snow resources, and provide tourists with the necessary fun of ice and snow sports tourism activities through scientific and technological means. 4.4. using multimedia technology to improve the operation and management intensity of ice and snow sports tourism in the context of the extensive application of multimedia technology, the development of ice and snow sports tourism activities needs to improve the coordination ability, and the coordination ability needs not only to focus on the improvement of the internal coordination ability of ice and snow sports tourism management, but also to clearly connect external factors. by building a multimedia digital platform for ice and snow sports tourism, the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset comprehensive management of ice and snow sports tourist attractions will be carried out to a greater extent from all aspects. during the safety management of ice and snow sports tourist attractions, humidity modules, temperature modules and lcd modules are installed inside the scenic spots to better understand the activity routes of passengers. the multimedia platform can shorten the safety warning time to a greater extent and fully improve the management efficiency of ice and snow sports tourist attractions. at the same time, based on the customized 5g+ar immersive intelligent crowd guidance service system and 360 degree panoramic image acquisition technology, tourists can solve the problems existing in the process of sightseeing, so that tourist groups can understand the actual situation of the site and the passenger flow, and tourists can choose the appropriate site according to their own level. in the process of supporting service management, the integration of infrastructure and services, independent software developers and other aspects should be combined to better create an offline data integration approach, promote the combination of online platforms and offline tourism, and further expand the function of ice and snow sports tourism. in the multimedia platform, tourism groups can get the dynamic information content of ice and snow sports tourism destinations, such as navigation, shopping guide, catering and accommodation, under the support of multimedia technology, we will carry out activities such as buying tickets and entering the park, solve the problem of insufficient human resource allocation in each scenic spot, and improve the overall management level of the scenic spot. 4.5. insist on market demand orientation and deeply develop new products in general, the development of ice and snow sports tourism products is from the whole process of product marketing and consumption. ice and snow sports tourism scenic spots should also pay full attention to the added value of ice and snow sports tourism products, build a well-known ice and snow brand, make full use of short videos, wechat platform and other multimedia boxes to promote ice and snow sports tourism products, and realize the publicity of ice and snow sports tourism products in multiple directions. under the background of market demand, develop ice and snow sports tourism products such as chemistry and ice and snow fishing, fully meet the spiritual needs of tourists, enhance product supply, and to a greater extent enhance the added value of the ice and snow sports tourism industry, making the ice and snow tourism industry chain more rich. 5. conclusion the maturity of multimedia technology can also provide the basic conditions for the construction of the ice and snow sports tourism industry internet, while changing the development mode of the ice and snow sports tourism industry. the highly developed information technology-based ice and snow sports tourism industry provides a perfect network chain. this network relationship is not an economic entity in the legal sense, it does not have the legal personality, but needs to break through the boundaries between traditional enterprises, form an internet model of integrated development. the internet transformation of the ice and snow sports tourism industry not only needs to adopt the multimedia management platform, but also needs to innovate and further improve the quality of the original products and resources, and needs to adjust the management structure between the ice and snow sports tourism projects and the various industrial units of the multimedia platform. under the support of multimedia technology, the advantages of the project are combined to fully meet the economic and social benefits of the ice and snow sports tourism project. in the era of multimedia, the speed of information transmission has mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset been unable to be expected. under the new development background, sustainable development thinking is required. the combination of ice and snow leisure sports and tourism industry in china enables multimedia technology to promote the integrated development of ice and snow leisure sports and tourism industry. during the application of multimedia technology in ice and snow sports tourism projects, supported by the multimedia platform, the diversified and multi-dimensional publicity of the continuous output of ice and snow leisure sports culture enables the public to better receive information about ice and snow leisure sports culture through the all media platform, which enables multimedia technology to promote the construction of high-level composite talents with chinese characteristics and knowledge of ice and snow leisure sports and tourism industry, under the support of the multimedia platform, a multi-party information communication platform will be built in combination with internet technology to integrate ice and snow sports resources and tourism resources according to the characteristics of the region, strengthen infrastructure construction, and clearly expand the venues with ice and snow leisure sports functions that can be experienced by more consumers, so that the ice and snow sports tourism projects will be improved accordingly to better meet people's tourism needs. references gu jiuxian. research on regional consumer demands and behavioral influence of the 2022 winter olympics— hebei winter sports tourism as example [j] sports & research, 2016, 37 (04): 114-120. shi shuqi. research on the application of new media in the winter olympic games -a case study of "snow and ice in china" app [c] //. compilation of papers of 2017 science and technology winter olympic forum and sports science and technology product exhibition. [publisher unknown], 2017: 7779. tong gang. exploration on the construction of national snow and ice sports culture under the background of the dream of strengthening china [j]. snow and ice sports, 2015, 37(04): 64-67+84. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset leveraging machine learning to optimize production processes and capacity in the brewery industry. 1eze ukamaka j ndubuisis, 2paul-darlington ibemezie, 3daniel ikechukwu egu and 4okolotu g.i. 1,2,3madonna university, nigeria 4department of agricultural engineering, faculty of engineering, delta state university of science and technology, p.m.b. 05, ozoro, nigeria. doi: https://doi.org/10.5281/zenodo.15024347 abstract: the decrease in the production capacity that had crippled business activities that mostly depend on soft drinks to run their daily activities was overcame by introducing leveraging machine learning to optimize production processes and capacity in the brewery industry, to perfectly achieve this, it was done in this approach, characterizing and establishing the causes of poor production capacity in a brewery industry, designing a conventional simulink model for production processes in the brewery industry, designing leverage machine learning rule base that will reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity, training ann in the designed machine learning rule base for effective reduction of the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity, designing a simulink model for leverage machine learning, developing an algorithm that will implement the process, designing a simulink model for leveraging machine learning to optimize production processes and capacity in the brewery industry and validating and justifying the percentage improvement in the production capacity of a brewery industry with and without leveraging machine learning. the results obtained were, that the conventional inefficient process control and automation cause of poor production capacity in the brewery industry was 20%. on the other hand, when leveraging machine learning was introduced in the system, it drastically reduced inefficient process control and automation caused poor production capacity in the brewery industry to 17.34% thereby enhancing the production capacity, the conventional lengthy fermentation and maturation times cause of poor production capacity in brewery industry was10%. meanwhile, when leveraging machine learning was incorporated into the system, it decisively reduced lengthy fermentation and maturation times caused by poor production capacity in the brewery industry to 8.7% and the conventional production capacity in the brewery industry was 50000 bottles of drink. on the other hand, when leveraging machine learning was inculcated in the system, it simultaneously enhanced the production capacity in the brewery industry to 6500 bottles of drink. finally, with these results obtained, it showed that production capacity in the brewery industry was optimized by 33%. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset keywords; learning, leveraging, machine, processes, production 1.1 introduction the brewery industry is highly competitive, with manufacturers continually seeking ways to optimize production processes, minimize waste, and maximize production capacity. traditional methods of process optimization in breweries rely heavily on manual observations, fixed schedules, and historical data that may not adapt swiftly to changing conditions (rathore & tiwari, 2020). in recent years, machine learning (ml) has emerged as a transformative technology in industrial manufacturing, offering advanced data-driven solutions that significantly improve process control and forecasting capabilities (zhou et al., 2021). machine learning algorithms can analyze large volumes of production data in real time, providing insights that enhance decision-making, streamline operations, and improve resource utilization (wuest et al., 2019). the brewery industry, due to its complex manufacturing processes involving various stages such as fermentation, bottling, and packaging, is uniquely positioned to benefit from machine learning applications. these algorithms can optimize fermentation times, monitor quality control in real time, and adjust operations dynamically based on demand and resource availability (oliveira & cunha, 2019). furthermore, machine learning supports predictive maintenance, reducing equipment downtime and minimizing disruptions in production cycles (agrawal et al., 2020). given the need for sustainable operations, machine learning also contributes to achieving energy efficiency, which aligns with industry goals to minimize environmental impact (lydon et al., 2021). however, integrating machine learning into brewery production faces several challenges, including the need for significant data infrastructure, skilled personnel, and an understanding of the nuances in applying ai-based solutions to traditional processes (singh & kumar, 2021). despite these challenges, the potential benefits have spurred research into developing tailored ml models that address the specific needs of the brewing industry. this study aims to explore how machine learning can be effectively leveraged to optimize production processes and increase capacity within breweries, ultimately contributing to a more sustainable, efficient, and competitive brewing industry. 2.0 methodology to characterize and establish the causes of poor production capacity in the brewery industry. here's an example of how poor production capacity in the brewery industry can be characterized by causes, with percentages and their corresponding impact in terms of bottles of drinks produced per day: table characterized and established causes of poor production capacity in a brewery industry mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cause of poor production capacity impact (%) impact (number of bottles per day) inefficient process control and automation 20% 10,000 fewer bottles equipment downtime and maintenance issues 25% 12,500 fewer bottles variability in raw material quality 10% 5,000 fewer bottles suboptimal scheduling and resource allocation 15% 7,500 fewer bottles lengthy fermentation and maturation times 10% 5,000 fewer bottles limited data utilization and real-time analytics 8% 4,000 fewer bottles energy constraints and environmental regulations 7% 3,500 fewer bottles labor shortages and skill gaps 5% 2,500 fewer bottles total production impact 100% 50,000 fewer bottles i) the table indicates the estimated contribution of each cause to the reduction in production capacity, expressed as a percentage and in terms of the reduction in bottles of drinks produced per day. ii) these values are estimates and may vary based on the specific brewery’s production environment and operational parameters. to design a conventional simulink model for production processes in the brewery industry mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1.0 designed conventional simulink model for production processes in the brewery industry the results obtained were shown in figures 9.0 to 11.0 sttation 1 transfer and loading station 2 filling station 3 capping variability in raw material quality in1 out1 unfilled bottles in 1 o u t 1 total production impact in1out1 in1 out1 out2 subsystem2 in1 out1 in 1 o u t 1 in1 out1 subsystem suboptimal scheduling and resource allocation in1 out1 scope 6 scope 5 no of filled botles 5e+004 no of crates in 1 o u t 1 limited data utilization and real -time analytics in1 out1 lengthy fermentation and maturation times in1 out1 labor shortages and skill gaps in1 out1 inefficient process control and automation in1 out1 fill ing system in 1 o u t 1 equipment downtime and maintenance issues in1 out1 energy constraints and environmental regulations in1 out1 empty bottles in 1 o u t 1 display 9 5e+004 display 8 5 display 7 7 display 6 8 display 5 10 display 4 15 display 3 10 display 2 25 display 1 4165 display 20 conventional 1 capping systemi in 1 o u t 1 capping in1 out1 out2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to design machine learning rule base that will reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity figure 2.0 machine learning fuzzy inference system machine learning fuzzy inference system was designed as shown in figure 2.0 to reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity this has three inputs of causes of poor production capacity, total production capacity and detecting sensor. it also has an output of result. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3.0 machine learning rule base machine learning rule base was also designed to reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity these rules were extensively elucidated in table 2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 2. 0: machine learning rule base the comprehensive rules of designed machine learning rule base, that will reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity is shown in table 2.0 1 if causes of poor production capacity is high reduce and total production capacity is low improve and detecting sensor is not effective rectify then result is poor production capacity in brewery industry 2 if causes of poor production capacity is partially high reduce and total production capacity is partially low improve and detecting sensor is partially not effective rectify then result is poor production capacity in brewery industry 3 if causes of poor production capacity is high reduce and total production capacity is partially low improve and detecting sensor is not effective rectify then result is poor production capacity in brewery industry 4 if causes of poor production capacity is low retain and total production capacity is high retain and detecting sensor is effective retain then result is high production capacity in brewery industry mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4.0: operational application of the four rules to train ann in the designed machine learning rule base for effective reduction of the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity, was shown in the operation of the four rules i figure 4.0 out 1 1 demux demux demux demux zero firing strength ? > 0 total firing strength totalproductioncapacity input mf switch rule 4 rule rule 3 rule rule 2 rule rule 1 rule result output mf midrange -cdemux defuzzification 1 coa detectingsensor input mf causesofpoorproductioncapacity input mf aggmethod 1 max in1 1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig 5 trained ann in the designed machine learning rule base for effective reduction of the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity ann was trained twenty times in four rules 20 x4 = 80 eighty rules that looks identical like human brain. . figure 6.0: result obtained during the training 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.2 0.3 0.4 0.5 0.6 0.7 0.8 w(i,1) w (i ,2 ) leveraging machine learning to optimize production processes and capacity in the brewery industry y{1}x{1} input 1 neural network x{1} y {1} display 1.2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 7.0: designed simulink model for leverage machine learning this will be integrated in figure 1.0 to obtain the results shown in figures 9.0 to11.0 to develop an algorithm that will implement the process, we have to go through the following process 1. characterize and establish the causes of poor production capacity in a brewery industry. 2. identify inefficient process control and automation 3. identify equipment downtime and maintenance issues 4. identify variability in raw material quality 5. identify suboptimal scheduling and resource allocation 6. identify lengthy fermentation and maturation times 7. identify limited data utilization and real-time analytics 8. identify energy constraints and environmental regulations 9. identify labor shortages and skill gaps 10. identify total production impact 11. design a conventional simulink model for production processes in the brewery industry and integrate 2 through 10 12. design leverage machine learning rule base that will reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity. 13. train ann in the designed machine learning rule base for effective reduction of the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity 14. design a simulink model for leverage machine learning y{1}x{1} input 1 powergui continuous video viewer video viewer imageimageimage a b c a b c subsystem1 in1 in2 in3 out1 connection portsubsystem in1 in2 out1 connection port raised cosine receive filter square root neural network x{1} y {1} gaussian noise generator gaussian fuzzy logic controller from multimedia file vipfly .avi v: 240 x320 , 15 fps image display 1 1.2 display 1.33 0 clock awgn channel awgn in1 1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 15. integrate 12 through 14 16. integrate 15 in 11 17. do the causes of poor production capacity in a brewery industry reduce? 18. if no go to 16 19. if yes go to 23 20. does the production capacity in a brewery industry improve? 21. if no go to16 22. if yes go to 23 23. optimized production processes and capacity in the brewery industry. 24. stop 25. end to design a simulink model for leveraging machine learning to optimize production processes and capacity in the brewery industry. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sttation 1 transfer and loading station 2 filling station 3 capping y{1}1x{1}1 input 1 powergui continuous video viewer video viewer imageimageimage variability in raw material quality in1 out1 unfilled bottles in 1 o u t1 total production impact in1out1 a b c a b c in1 out1 out2 subsystem4 in1 in2 in3 out1 connection portsubsystem3 in1 in2 out1 connection port subsystem2 in1 out1 in 1 o u t1 in1 out1 subsystem suboptimal scheduling and resource allocation in1 out1 scope 6 scope 5 raised cosine receive filter square root neural network 1 x{1} y {1} no of filled botles 5e+004 no of crates in 1 o u t1 limited data utilization and real -time analytics in1 out1 lengthy fermentation and maturation times in1 out1 labor shortages and skill gaps in1 out1 inefficient process control and automation in1 out1 gaussian noise generator gaussian fuzzy logic controller 1 from multimedia file vipfly .avi v: 240 x320 , 15 fps image fill ing system in 1 o u t1 equipment downtime and maintenance issues in1 out1 energy constraints and environmental regulations in1 out1 empty bottles in 1 o u t1 display 9 6.65e+004 display 8 4.336 display 7 6.07 display 6 6.937 display 5 8.671 display 4 13 .01 display 3 8.671 display 2 21 .68 display 12 1.2 display 11 1.33 display 1 4165 display 17 .34 0 clock capping systemi in 1 o u t1 capping in1 out1 out2 awgn channel awgn in1 1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig 8 designed simulink model for leveraging machine learning to optimize production processes and capacity in the brewery industry. the results obtained were as shown in figure 9.0 to 11.0 to validate and justify the percentage improvement in the production capacity of a brewery industry with and without leveraging machine learning to find percentage improvement in the reduction of inefficient process control and automation cause of poor production capacity in brewery industry with leveraging machine learning conventional inefficient process control and automation =20% leveraging machine learning inefficient process control and automation =17.34% %improvement in the reduction of inefficient process control and automation cause of poor production capacity in brewery industry with leveraging machine learning= conventional inefficient process control and automation leveraging machine learning inefficient process control and automation %improvement in the reduction of inefficient process control and automation cause of poor production capacity in brewery industry with leveraging machine learning= 20% 17.34% %improvement in the reduction of inefficient process control and automation cause of poor production capacity in brewery industry with leveraging machine learning=2.66% to find percentage improvement in the reduction of lengthy fermentation and maturation times cause of poor production capacity in brewery industry with leveraging machine learning conventional lengthy fermentation and maturation times =10% leveraging machine learning lengthy fermentation and maturation times =8.7% %improvement in the reduction of lengthy fermentation and maturation times cause of poor production capacity in brewery industry with leveraging machine learning= conventional lengthy fermentation and maturation times leveraging machine learning lengthy fermentation and maturation times %improvement in the reduction of lengthy fermentation and maturation times cause of poor production capacity in brewery industry with leveraging machine learning=10% 8.7% %improvement in the reduction of lengthy fermentation and maturation times cause of poor production capacity in brewery industry with leveraging machine learning=1.3% to find percentage improvement in the production capacity in brewery industry with leveraging machine learning conventional production capacity =50,000bottles leveraging machine learning production capacity =6, 6500bottles %improvement in the production capacity in brewery industry with leveraging machine learning= mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset leveraging machine learning production capacity conventional production capacity x 100% conventional production capacity 1 %improvement in the production capacity in brewery industry with leveraging machine learning= 6, 6500bottles 50,000bottles x100% 50,000bottles 1 %improvement in the production capacity in brewery industry with leveraging machine learning=33% 3.0 4.0 results and discussions table 3 comparison of conventional and leveraging machine learning inefficient process control and automation cause of poor production capacity in brewery industry time (days) conventional inefficient process control and automation cause of poor production capacity in brewery industry (%) leveraging machine learning inefficient process control and automation cause of poor production capacity in brewery industry (%) 1 20 17.34 2 20 17.34 3 20 17.34 4 20 17.34 10 20 17.34 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 9.0: comparison of conventional and leveraging machine learning inefficient process control and automation cause of poor production capacity in brewery industry the conventional inefficient process control and automation cause of poor production capacity in brewery industry was20%. on the other hand, when leveraging machine learning was introduced in the system, it drastically reduced inefficient process control and automation cause of poor production capacity in brewery industry to17.34% thereby enhancing the production capacity. 1 2 3 4 5 6 7 8 9 10 17 17.5 18 18.5 19 19.5 20 in e f f ic ie n t p r o c e s s c o n t r o l a n d a u t o m a t io n c a u s e o f p o o r p r o d u c t io n c a p a c it y in b r e w e r y in d u s t r y ( % ) time (days) conventional inefficient process control and automation cause of poor production capacity in brewery industry (%) leveraging machine learning inefficient process control and automation cause of poor production capacity in brewery industry (%) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4 comparison of conventional and leveraging machine learning lengthy fermentation and maturation times cause of poor production capacity in brewery industry time (days) conventional lengthy fermentation and maturation times cause of poor production capacity in brewery industry (%) leveraging machine learning lengthy fermentation and maturation times cause of poor production capacity in brewery industry (%) 1 10 8.7 2 10 8.7 3 10 8.7 4 10 8.7 10 10 8.7 figure 10.0: comparison of conventional and leveraging machine learning lengthy fermentation and maturation times cause of poor production capacity in brewery industry the conventional lengthy fermentation and maturation times cause of poor production capacity in brewery industry was10%. meanwhile, when leveraging machine learning was incorporated in the system, it decisively 1 2 3 4 5 6 7 8 9 10 8.5 9 9.5 10 l e n g th y f e rm e n ta ti o n a n d m a tu ra ti o n t im e s c a u s e o f p o o r p ro d u c ti o n c a p a c it y i n b re w e ry i n d u s tr y ( % ) time (days) conventional lengthy fermentation and maturation times cause of poor production capacity in brewery industry (%) leveraging machine learning inefficient lengthy fermentation and maturation times cause of poor production capacity in brewery industry (%) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset reduced lengthy fermentation and maturation times cause of poor production capacity in brewery industry to 8.7%. table 5 comparison of conventional and leveraging machine learning production capacity in brewery industry time (days) conventional production capacity in brewery industry (bottles) leveraging machine learning production capacity in brewery industry (bottles) 1 50000 6 6500 2 50000 6 6,500 3 50000 6 6,500 4 50000 6 6,500 10 50000 6 6,500 fig 11 comparison of conventional and leveraging machine learning production capacity in brewery industry the conventional production capacity in brewery industry was 50000bottles of drink. on the other hand, when leveraging machine learning was inculcated in the system, it simultaneously enhanced the production capacity in a brewery industry to6 6500 bottles of drink. finally, with these results obtained, it showed that production capacity in a brewery industry was optimized by 33%. 1 2 3 4 5 6 7 8 9 10 5 5.2 5.4 5.6 5.8 6 6.2 6.4 6.6 6.8 x 10 4 p ro d u c ti o n c a p a c it y i n b re w e ry i n d u s tr y ( b o tt le s ) time (days) conventional production capacity in brewery industry (bottles) leveraging machine learning production capacity in brewery industry (bottles) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4.0 conclusion the consistent poor production capacity experienced in a brewery industry is anchored on these factors, inefficient process control and automation, equipment downtime and maintenance issues, variability in raw material quality, suboptimal scheduling and resource allocation, lengthy fermentation and maturation times, limited data utilization and real-time analytics, energy constraints and environmental regulations, labor shortages and skill gaps coupled with total production impact. this was overcame by introducing leveraging machine learning to optimize production processes and capacity in the brewery industry, to perfectly achieve this, it was done in the approach, characterizing and establishing the causes of poor production capacity in a brewery industry, designing a conventional simulink model for production processes in the brewery industry, designing leverage machine learning rule base that will reduce the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity, training ann in the designed machine learning rule base for effective reduction of the causes of poor production capacity in a brewery industry and simultaneously increase the production capacity, designing a simulink model for leverage machine learning, developing an algorithm that will implement the process, designing a simulink model for leveraging machine learning to optimize production processes and capacity in the brewery industry and validating and justifying the percentage improvement in the production capacity of a brewery industry with and without leveraging machine learning. the results obtained were, the conventional inefficient process control and automation cause of poor production capacity in brewery industry was20%. on the other hand, when leveraging machine learning was introduced in the system, it drastically reduced inefficient process control and automation cause of poor production capacity in brewery industry to17.34% thereby enhancing the production capacity, the conventional lengthy fermentation and maturation times cause of poor production capacity in brewery industry was10%. meanwhile, when leveraging machine learning was incorporated in the system, it decisively reduced lengthy fermentation and maturation times cause of poor production capacity in brewery industry to 8.7% and the conventional production capacity in brewery industry was 50000bottles of drink. on the other hand, when leveraging machine learning was inculcated in the system, it simultaneously enhanced the production capacity in a brewery industry to6 6500 bottles of drink. finally, with these results obtained, it showed that production capacity in a brewery industry was optimized by 33%. references agrawal, a., gans, j. s., & goldfarb, a. (2020). machine learning, process control, and industrial production. mit press. lydon, m., kim, j., & yang, c. (2021). machine learning in manufacturing: an overview of applications in process optimization. journal of manufacturing processes, 54, 112–128. https://doi.org/10.1016/j.jmapro.2020.11.029 mailto:topacademicjournals@gmail.com https://doi.org/10.1016/j.jmapro.2020.11.029 academic journal of science, engineering and technology vol. 10, issue 1; january -february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset oliveira, j., & cunha, l. m. (2019). smart breweries: applications of machine learning in beer production. food engineering reviews, 11(2), 75–89. https://doi.org/10.1007/s12393-019-09167-4 rathore, a., & tiwari, m. k. (2020). advanced manufacturing technologies for the brewery industry. industrial journal of brewing, 126(3), 345–360. https://doi.org/10.1111/ijbc.12352 singh, s., & kumar, s. (2021). challenges in ai and machine learning applications in traditional industries. ai in manufacturing journal, 4, 23–35. https://doi.org/10.1016/j.aim.2020.12.001 wuest, t., weimer, d., irgens, c., & thoben, k. d. (2019). machine learning in manufacturing: advantages, challenges, and applications. production engineering, 13(2), 175–187. https://doi.org/10.1007/s11740019-00847-3 zhou, b., dai, w., & yang, h. (2021). machine learning for smart manufacturing: a literature review. journal of manufacturing science and engineering, 143(4), 1–13. https://doi.org/10.1115/1.4049023 mailto:topacademicjournals@gmail.com https://doi.org/10.1007/s12393-019-09167-4 https://doi.org/10.1111/ijbc.12352 https://doi.org/10.1016/j.aim.2020.12.001 https://doi.org/10.1007/s11740-019-00847-3 https://doi.org/10.1007/s11740-019-00847-3 https://doi.org/10.1115/1.4049023 academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset megafossil trees reveal past landscapes of the swedish scandes maria sofia andersson and olof erik johansson department of ecology and environmental science, umeå university, se 901 87 umeå, sweden abstract: the structure and plant species composition of late-glacial and early-holocene landscapes in the swedish scandes are poorly understood. traditional pollen analytical inferences, glacier histories, and textbook narratives are beset with inaccuracies and uncertainties, particularly in high-mountain regions. more direct, robust, and reliable megaand macrofossil records provide unambiguous evidence of the former early local presence of tree species at specific sites and elevations, far beyond modern treelines. keywords: megafossils, treelines, holocene, scandes, climate, plant species introduction the structure and plant species composition of late-glacial andearly-holocenelandscapes in the swedish scandes are poorly comprehended. in this respect, traditional pollenanalytical inferences, glacier histories and textbook narratives are beset with inaccuracies and uncertainties, particularly in high-mountain regions (e.g.lundqvist 1969; huntley & birks 1983; berglund et al. 1996; karlén&kuylenstierna 1996;barnekow 1999; johnsen 2010).these methodological shortcomingsareevidenced by analyses of more direct, robust and reliable megaand macrofossil records (cf. helama et al. 2004; paus 2013; paus &haugland 2017;kullman 2017a). unambiguously, these approaches are stating formerearly local presence of tree species at specific sites and elevations, far beyond modern treelines. megafossil1 tree remains, representing former higher-than-present alpine treelines, mainly preserved in peat and lake mud, have for long been known and discussed in the scandes. these records have contributed broad outlines of the holocene history of high mountain landscape and climate evolution (smith 1920; lundqvist 1969;karlén 1976; kullman 1995; aas&faarlund 2000; kullman&kjällgren 2000, 2006). however, studies of this kind are constrained by sparsity of peat as an efficient preservation medium at high elevations, which has urged for alternative megafossil archives when searching for the highest positions of tree growth during earlier epochs. 1megafossils are large pieces of wood, which are preserved near their growth places and which can be accurately determined to species and dated by the 14c-method. ages are reported as calendar years bp (ad 1950), by intercept-values, and derive from sources, cited above. megafossilrecords, originating from different elevations above the modern treeline, havedisplayed a discernible trend of treeline lowering throughout the holocene, about 50 m per millennium(kullman 1995; kullman&kjällgren 2000), in broadagreement with orbital forcing of insolation at the top of the atmosphere (berger &loutre 1991). since thismechanism suggested a thermal maximum somewhat prior to the earliest and highest existingrecords, further search for megafossil wood remnants was extended to even higherelevations. particular focus was on the fringes of currently melting glaciers and snow/ice patches alongthe entire swedish scandes (fig.1). in addition, these efforts were inspired by positive results, basedon megafossils, from emerging proglacial sites worldwide, showing that forest trees hadprevailedat sites until recently covered by ice, during earlier parts of the holocene,(nicolussi&patzelt 2000;schlüchter&jörin 2004; benedict et al. 2008; ivyochs et mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset al. 2009; koch et al.2014). prior to the studies reviewed in this study, no such discoveries had been reported from the scandes. results of these recent investigations, carried out in different parts of the swedish scandes, constitute the main core of this paper.the present review upsets the traditional comprehension of the late-glacial andearly postglacial climate as well asthe structure and composition of the high-elevation landscape (cf. paus 2013; kullman 2013; luoto et al. 2014;väliranta et al. 2015; schenk et al. 2018). possibly, the emerging views mayserve as proxy analogues of future subalpine landscapes in a potentially warmer world.in fact, the initial phase of such a course of change may be already underway in the swedish scandes (kullman 2010, 2019). however, such projections should be treated cautiously, since future directions of the climate evolution remain uncertain. figure 1. subfossil pine, which inspired search for megafossils at exceptionally high elevations,particularly on the forefields of receding glaciers. the lower fringe of the glacier “sylglaciären”, 1195 m a.s.l., about 400 m higher than the present treeline. radiocarbon yielded 10 425 cal. yr bp. photo: 1997-07-16. source: kullman&kjällgren 2000. results late-glacial and early-holocenetrees as evidenced by megafossils-the new landscape perspective all main tree species of the current treeline ecotone were present on what has to be interpreted as ice-free nunataks(fig. 2-5) already at the late-glacial/early-holocene transition, 17 00013 000years before the present day (bp) at unprecedented high elevationsalong the entire swedish scandes(kullman&kjällgren 2000; kullman 2002, 2004). these species are mountain birch (betulapubescens ssp. czerepanovii), norway spruce (piceaabies) and scots pine (pinussylvestris). henceforth,these will be cited as betula, picea and pinus, respectively. the core site for discovery of the earliest tree megafossils is mt. åreskutan (1420 m a.s.l.) in the southern swedishscandes (province of jämtland), 1360 m a.s.l. and 510 m above the treeline of pine. this mountain has, close to its summit, until quite recently,harboured an ice patch or asmall glacier, which has gradually vanished in response to 20th century climate warming andconsequently megafossil trees have been exposed (figs. 2 & 3). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2. locus classicus, 1360 m a.s.l.,the site for the discovery of late-glacial and early-holocene tree presence on early emergingnunataks in the scandes (kullman 2002). these findings have changed the conception of the earliestsubalpine/alpine landscape-history. a. a small glacier/ice patch prevailed here until quite recently. its former position is indicated by the snow patch and the row of blocks in the foreground. the snow has completely melted by the end of late summer during most years of the past few decades. photo: 2018-07-18.b. the former ice-distribution embraced the green moss-covered area in the center. here, most of the megafossils have been recovered, reasonably dislocated downslope by snow avalanches from higher upslope positions. photo: 20180901. figure 3. overview of the earliest megafossils recovered at theåreskutan-site, 1360 m a.s.l. a. pinussylvestris, 13 810 cal. yr bp. b. piceaabies, 13 010 cal. yr bp. c. betulapubescenss.lat., 16 810 cal. yr bp. these samples highlight earlier local deglaciation and tree instatement than previously inferred by more traditional approaches. source: kullman 2002. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4. examples of late-glacial megafossil tree recoveries at sites along the entire swedish scandes. a. the glacier helagsglaciären (province of härjedalen), has receded areally by c. 40% during the past 100 years. photo: 2015-08-13. b. close to its former lower maximum range, 1150 m a.s.l., megafossils of pinus were recovered and dated 13 145 cal. yr bp. photo: 2008-07-04. source: kullman&kjällgren 2000.c. the glacier tärnaglaciären (province of lapland). currently, a large snow-field prevails in the mid-slope below the glacier, which extended down to the mid of the lake (1070 m a.s.l.) about 100 years ago(lindgren &strömgren 2001). photo:2010-08-20. d. preserved in a downwashed peat-cake 630 m a.s.l., a cone of piceawas dated 11 200 cal. yr bp. photo: 2017-09-01. e. the glacier kårsaglaciären, 965 m a.s.l. (province of lapland). photo: 2009-08-21. f. a megafossil remnant of pinus appeared in the outwash stream from beneath the glacierkårsaglaciären, 955 m a.s.l. it dated 11 760 cal. yr bp. photo: 2008-09-17. source: öberg &kullman 2011.g. mt. städjan (province of dalarna), 1100 m a.s.l. h. megafossilpinus protruding from a thin soil layer between boulders in the south-facing slope of mt. städjan. dating yielded 12 425 cal. yr bp. photo: 2007-07-14. the firm evidence, presented above, conflicts with traditional glacial geologic and paleobotanical opinions and have been questioned and opposed by proponents and defenders of these approaches, drawing on negative evidence (birks et al. 2005) and refuted by kullman (2006). holocene megafossils in their settings below, a representative sample of megafossils recovered in geomorphic glacial cirques, with currently receding ice cover,ispresented. this is a comprehensive and richly illustrated review of previously published data and updates, representing the swedish scandes, from south to north (öberg & kullman 2011, kullman & öberg 2013, 2015; kullman 2017a,b) (figs. 5-20). a popular overview is given by kullman & öberg (2019). surprisingly, little research on these issues has been carried out in scandinavia by palaeoecologists, although archaeologists, particularly in norway, are making rich findings of human artifacts on the forefields of melting glaciers and ice patches (e.g. nesje et al. 2011). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5.the position of the glacier sites, particularly focused in this review. 1. helags-sylarna glaciers. 2.the glacier tärnaglaciären with adjacent ice patches. 3. glaciers and snow/ice patches in northern lapland. 1.helags-sylarna glaciers figure 6. downwashed stem of betula, 1345 m a.s.l., which dated 8620 cal. yr bp. mt. helagsfjället. photo: 201008-11. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 7. subfossil betula, extracted from eroding moss-cover in a downstream proglacial delta below the glacier, 1350 m a.s.l. dating yielded 9520 cal. yr bp. mt. helagsfjället. photo: 2006-10-15. figure 8.a. remnant of a fairly stout betula-tree, uplifted from beneath the moss-cover in the delta below storsylglaciären, 1275 m a.s.l. presumably, the original growth position was higher upslope. dating yielded 7170 cal. yr bp. photo: 2001-08-22.b. a downwashedpinus-remnant, 1210 m a.s.l., recovered well below its assumed original growth position, underneath the background ekorrglaciären. radiocarbon-dating gave9530 cal.yr bp. photo: 2008-08-24. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. the glacier tärnaglaciären with adjacent ice patches figure 9. “high-flying” betula-megafossil at the margin of an ice-patch adjacent to tärnaglaciären, 1425 m a.s.l. this is 635 m higher than the current local treeline. dating yielded 9195 cal. yrbp.murtsergure ice patch. photo: 2012-08-28. figure 10. piece of a betula-stem, recovered 1410 m a.s.l., 700 m higher than the nearest present-day treeline. it is currently being washed downslope from a growth place close to an ice-patch, adjacent to the glaciertärnaglaciären. it dated 9365 cal. yr bp.photo:2017-09-01. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 11. betula-megafossil, protruding from the snow rime at the glacier front, 1395 m a.s.l. this site is 685 m higher than the current local treeline. dating yielded 9450 cal. yr bp. the glacier tärnaglaciären. photo: 20170901. figure 12. a virtually new source of past high-mountain vegetation composition is provided by outwashed ”peatballs” of this kind. here uplifted from behind a stone in the main melt-water stream. their content of plant remains represents some of the former plant cover composition were ice prevailed until quite recently (see fig.13). ice-patch near the glaciertärna-glaciären, 1115 m a.s.l. photo: 2012-09-22. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 13. tree remains of different species contained in “peat balls”, released from beneath glacier ice in the tärna region (source: kullman& öberg 2013). except for common forest bryophytes and dwarf-shrubs, cones of larixsibirica and piceaabies as well as leaves of deciduous boreal tree species, have been extracted and radiocarbondated; a. b. larixsibirica, 7320 cal. yr bp.c. piceaabies, 8450 cal. yr bp. d. pinussylvestris, 7960 cal. yr bp. e. sorbusaucuparia, 8460 cal. yr bp. f. populustremula 8590 cal. yr bp. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. glacier and snow/ice patches in northern lapland . figure 14. trunk of pinus, dug out from glacier sediment, 940 m a.s.l. obviously, it is worked by beaver (castor fiber), indicative of a local forest environment at the dated time; 9280 cal. yr bp. the glacierkårsaglaciären. photo: 2008-09-17. figure 15. megafossil remains of betula, exposed just outside the lower glacer margin and much higher than the present local treeline, 990 m ö.h. they date 1950 cal. yr bp and support a general conception of a warmerthanpresent time, with a smaller glacier (kullman 2013). the glacier kårsaglaciären. photo: 2013-09-12. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 16.a. the glacierkåppasglaciären, c. 9 km west of abisko in swedish lapland. today, it should possibly be characterized as an ice-field. it released a megafossilpinus at its lower margin, 1030 m a.s.l.b. dating yielded 7860 cal. yr bp. photo: 2010-08-28 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 17.a. an elongated snow/ice patch, located c. 15 km northwest of abisko, extending 975-980 m a.s.l. at the lower margin, an extensive stone pavement indicates a prior more extensive size of this object. the front is currently disintegrating by “calving”, which exposes new mineral ground with some emerging megafossil tree remans. photo: 2010-08-30.b. megafossilpinus, dated 8900 cal. yr bp, up-raised from original position. photo: 2010-08-30.c. basal part of a betula-stem, possibly preserved in situ, 975 m a.s.l. radiocarbon-dating gave 5800 cal. yr bp.låktatjåkka ice field. photo: 2010-08-30. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 18.a. the glacier kitteldalsglaciären in the kebnekaise-massif. the lower front is about 1190 m a.s.l. megafossils of pinus and betula are recovered along the right-hand (east-facing) margin of the glacier. photo: 201308-11.b. pinus-log melting out from the glacier, 1240 m a.s.l. it dated 9010 cal. yr bp and is located 690 m higher than the local present-day treeline.photo: 2013-08-11. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 19. the glacier storglaciären in the kebnekaise-massif is one of the most thoroughly investigated glaciers in the swedish scandes, although mainly with respect to size and mass balance changes. about 100 years ago the lower front was close to the lake, c. 1115 m a.s.l. (cf. holmlund 2012). photo: 2013-08-13 figure. 20. a.megafossillog of betula, which dated 8490 cal. yr bp, 1100 m a.s.l. photo: 2013-0830.b.downwashed peat cake, containing a picea cone shell, 1105 m a.s.l. photo: 2013-08-13.c. apiceaconeshell dated 8380 cal. yr bp. the glacier storglaciären. synthesis and discussion demonstrably, alpine glaciers along the entire scandes have been melting over much of the past century (lundqvist 1969; holmlund et al. 1996, bakke et al. 2008). at their lower fronts, mega fossil tree remnants of different species are currently exposed. radiocarbon-dated, these samples provide a new view of the lateglacial and early-holocene high mountain landscape. it now stands out, that along the entire swedish scandes, all of our common tree species grew in small isolated populations, much earlier and at higher positions, than ever evidenced or contemplated. main features are quantified and summarized in table 1. the highest relative treeline positions and reasonably, the highest summer temperatures were attained 10 000-9500 cal. yr bp. this inference agrees with temperature reconstructions from other northern regions (e.g.shenk et al. 2020;mörner et al. 2020) the discussion below draws on an “amalgam” of previously published original studies, based on megafossils retrieved from glacier forefields (kullman 2004; öberg & kullman 2011, kullman & öberg 2013, 2015; kullman 2017a,b). these references provide additional detail and documentation to the images, which make up the core of this paper. table 1. for each of the study sites (fig. 5), age range of all megafossils, given as cal. yr bp, and corresponding relative elevation range of sample sites, displayed as altitudinal meters above the current treeline. site age-range relative elevation range 1 16 810-6100 115-585 2 9530-4480 225-700 3 11 760-1950 80-690 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a particular noteworthy novelty is that boreal trees grew at sites of present-day glaciers already during the lateglacial as early as about 17 000-12 000 years before the present. analogous inferences are presented from the norwegian scandes (paus et al. 2011). taken together, these discoveries have a bearing both on glacier and vegetation history. the common wisdom, until present, has been that the high mountains were completely icecovered at this early stage (lundqvist 1986, 1994), a viewquestioned (e.g. by dahl et al. 1997; follestad 2003; hörnberg et al. 2006;goeringa et al. 2008), and certainly not compatible with the presence of trees, if not assuming supraglacial tree growth. in fact, the last-mentioned option is discussed by different authors (fickert et al. 2007; zahle et al. 2018). the ice-free glacier cirques displayed the character of outlying forest enclaves, high above the closed and continuous forest below. prior to 10 000 bp, the dated samples are too few to form definite opinions about the relative abundance of betula,pinus and piceain the concerned habitats, although all three species were present at high elevations during that period, as evidenced by this review. possibly, the contemporary sparsity of recoveries related to still incomplete deglaciation and relatively small areas available for tree growth on the nunataks. since about 10 000 years bp, betula appears to have formed the upper treeline in these habitats, although pinus is found to have joined betula at the highest elevations, 600-700 m above current treelines, as these appeared during the past 10 years or so (kullman & öberg 2009; kullman 2013). except for the dominating tree species particularly focused and depicted in this study, the early tree vegetation contained an array of sub-ordinate boreal tree species, which today prevail sparsely in the mountain forest below. these species are sorbusaucuparia, alnusincanaandpopulustremula, all documented by megafossils (kullman& öberg 2013, 2015). presumably, the late-glacial and early-holocene nunatak tree groves may have served as dispersal nodes for trees and other plants, enabling their rapid subsequent downslope spread and establishment over the ice-free landscape as it gradually emerged (cf. väliranta et al. 2011, 2015). it is of particular interest to find that,piceaabies occurred on a regular basis and at unprecedented high elevations above its current treeline, and so even during the late-glacial. this contrasts with the orthodox view (based on pollen analysis) of spruce as a particularly late postglacial immigrant to western and high-elevation sweden (moe 1970; giesecke& bennett 2004; seppä et al. 2009). encouraged by the megafossil evidence presented above, some researchers, drawing on microfossils and dna-technique, support the option of early holocene presence of piceain the high-mountains(segerström& von stedingk 2003;hörnberg et al. 2006;paus 2010; paus et al. 2011; parducci et al. 2012; carcaillet et al. 2012). in addition, during the early holocene, the concerned tree groves harboured a tree species not growing spontaneously in sweden today, namelylarixsibirica(kullman 2018), which also occurred outside the present kind of habitats along the entire scandes, both in sweden and norway (kullman 1998; bergman et al. 2004; paus 2010;carcaillet et al. 2012).possibly this light-demanding species was outcompeted by advancing denser populations ofbetula and picea by the mid-holocene, as these species were favored by the evolving neoglacial climate, which then turned to a more oceanic and snow-richcharacter (cf. kullman 2018). by analogy with the rich tree flora, it is reasonable to assume that plant species richness in general was high in these, obviously sparse high-elevationtree stands. this gains support from analyses of plant remains in peat-cakes released from beneath the glacier ice (cf. kullman & öberg 2013, 2015). the presence of tree assemblages is suggested also from the fact that beaver (castor fiber), an obligate forest dweller, utilized trees growing in these sites (fig. 14). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset tentatively, the maximum difference by 700 m between the early-holocene treeline position and the present treeline may be translated into summer temperature change decline over this period of time. based on a general temperature lapse rate of 0.6 °c per 100 m altitude (laaksonen 1976), it may be inferred that the temperature has lowered by 4.2 °c since 9500 cal. yr ago. however, this figure, has to be adjusted due to the effect of subsequent glacio-isostatic land uplift, which here may be in the order of 200 m (påsse&andersson 2005). this reduces the figure on which temperature change may be calculated to 500 m and consequently a temperature 3.0 °c higher than at the present day. a warmer climate in the future, as commonly alleged, may turn the high mountain landscape into a state envisioned by the findings for the early holocene, as depicted in this study. tentatively, this implies a highmountain landscape, virtually without glaciers and large late-lying snow/ice patches. the former sites of these elements are likely to stand out as isolated treed oases high above the continuous forest. the surrounding more wind-exposed and snow-poor terrain remains virtually untreed, by analogy with the reluctance of trees and forests to colonize this type of habitats in response to the warming of the past 100 years (kullman & öberg 2009). references aas, b. &faarlund, t. 2000. forest limits and the subalpine birch belt in north europe with focus on norway. ams-varia 37, 103-147. bakke, j., lie, ø., dahl, s.o., nesje, a. &bjune, a.e. 2008. strengths and spatial pattern of the holocene wintertime westerlies in the ne atlantic region. global and planetary change 60, 28-41. barnekow, l. 1999. holocene tree-line dynamics and inferred climatic changes in the abisko area, northern sweden, based on macrofossil and pollen records. the holocene 9(3), 253-265. benedicht, j.b., benedicht, r.j., lee, c.m. & staley, d.m. 2008. spruce trees from a melting ice patch: evidence for holocene climatic change in the colorado rocky mountains, usa. the holocene 18, 1067-1076. berger, a. &loutre, m.f. 1991. insolation values for the climate of the last 10 million years. quaternary science reviews 10, 297-317. berglund, b., barnekow, l., hammarlund, d., sandgren, p. & snowball, i.f. 1996. holocene forest dynamics and climate changes in the abisko area, northern sweden – the sonesson model of vegetation history reconstructed and confirmed. ecological bulletins 45, 15-30. bergman, i., olofsson, a., hörnberg, g., zackrisson, o. &hellberg, e. 2004. deglaciation and colonization; pioneer settlements in northern fennoscandia. journal of world prehistory 18, 155-177. birks, h.h., larsen, e. & birks, h.j.b. 2005. did tree-betula, pinus and picea survive the the last glaciation along the west coast of norway? a review of the evidence in light of kullman (2002). journal of biogeography 32, 1461-1471. carcaillet, c., hörnberg, g. &zackrisson, o. 2012. woody vegetation, fuel and fire track the melting of the scandinavian ice-sheet before 9500 cal.yr bp. quaternary research 78(3), 540-548. dahl, s.o., nesje, a. &øvstedal, j. 1997. cirque glaciers as morphological evidence for a thin younger dryas ice sheet in east-central southern norway. boreas 26, 161-180. fickert, t., friend, d., grüninger, f., molina, b. & richter, m. 2007. did debris-covered glaciers serve as pleistocene refugia for plants? a new hypothesis derives from observations of recent plant growth on glacier surfaces. arctic, antarctic, and alpine research 39, 245-257. follestad, b. 2003. development of minor late-glacial ice domes east of opdal, central norway. norgesgeologiskeundersøkelsebulletin 441, 39-49. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset goehringa, b.m., brook, e.j., linge, h., raisbeck, g.m. &yiou, f. 2008. beryllium-10 exosure ages of erratic boulders in southern norway and implications for the history of the fennoscandian ice sheet. quaternary science reviews 27, 320-336. helama, s., lindholm, m., timonen, m. &eronen, m. 2004. dendrochronologically dated changes in the limit of pine, northwest finland during the past 7.5 millennia. boreas 33, 250-259. holmlund, p., karlén,w. &grudd, h, 1996. fifty years of mass balance and glacier front observations at the tarfala research station, geografiskaannaler 78a, 105-114. hörnberg, g., bohlin, e., hellberg, e., bergman, i., zackrisson, o., olofsson, a. &wallin, j.-e. 2006. effects of mesolithic hunter-gatherers on local vegetation in a non-uniform glacio-isostatic land uplift area, northern sweden. vegetation history and archaeobotany 15, 13-26. huntley, b. & birks, h.j.b. 1983. an atlas of past and present pollen maps for europe: 0-13000 years ago. cambridge university press, cambridge. ivy-ochs, s., kerschner, h., maisch, m. cristl, m. kuabik, p. w. &schlűchter, c. 2009. latest pleistocene and holocene glacier variations in the european alps. quaternary science reviews 28, 2137-2149. johnsen, t.f. 2010. late quaternary ice sheet history and dynamics in central and southern scandinavia. phdthesis, stockholm university, sweden. karlén, w. 1976. lacustrine sediments and tree-limit variations as indicators of holocene climatic fluctuations in lappland, northern sweden. geografiskaannaler 55a, 29-63. karlén, w. &kuylenstirena, j. 1996. on solar forcing of holocene climate: evidence from scandinavia. the holocene 6(3), 359-365. koch, j., clague, j.j. & osborn, g. 2014. alpine glaciers and permanent ice and snow patches in western canada approach their smallest sizes since the mid-holocene consistent with global trends. the holocene 24(2), 1639-1648. kullman, l. 1995. holocene tree-limit and climate history from the scandes mountains, sweden. ecology 76, 2490-2502. kullman, l. 1998. palaeoecological, biogeographical and palaeoclimatological implications of early holocene immigration of larixsibiricaledeb. into the scandes mountains, sweden. global ecology and biogeography letters 7, 181-188. kullman, l. 2002. boreal tree taxa in the central scandes during the late-glacial: implications for latequaternary forest history. journal of biogeography 29, 1117-1124. kullman, l. 2004. early holocene apperance of mountain birch (betulapubescens ssp. tortuosa at high elevations in the swedish scandes: megafossil evidence exposed by recent snow and ice recession. arctic, antarctic, and alpine research 30, 172-180. kullman, l. 2006. late-glacial trees from arctic coast to alpine tundra. journal of biogeography 33, 376. kullman, l. 2010. a richer, greener and smaller alpine world: review and projection of warming-induced plant cover change in the swedish scandes.ambio 39, 159-169. kullman, l. 2013. ecological tree line historyand palaeoclimate – review of megafossil evidence from the swedish scandes. boreas 42, 55-567. kullman. 2017a. melting glaciers in the swedish scandes provide new insights into palaeotreeline performance. international journal of current multidisciplinary performance 3(3), 607-618. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset kullman, l. 2017b. further details on holocene treeline, glacier/ice patch and climate history in swedish lapland. international journal of research in geography 3(4), 61-69. kullman, l. 2018. larix an overlooked taxon in boreal vegetation. a review with perspective on incongruencies between megafossil and pollen records. geo-öko 39, 90-110. kullman, l. 2019. early signs of a fundamental subalpine ecosystem shift in the swedish scandes – the case of the pine (pinussylvestris l.)treeline ecotone. geo-öko 40, 122-175. kullman, l. &kjällgren l. 2000. a coherent postglacial tree-limit chronology (pinussylvestris l.) for the swedish scandes: aspects of paleoclimate and ”recent warming”, based on megafossil evidence. arctic, antarctic and alpine research 32, 419-428. kullman, l. &kjällgren l. 2006. holocene pine tree-line evolution in the swedish scandes: recent tree-line rise and climate change in a long-term perspective. boreas 35(1), 159-168. kullman, l. & öberg, l. 2009. postlittle ice age tree line rise and climate warming in the swedish scandes: a landscape ecological perspective. journal of ecology 97, 415-429. kullman, l. & öberg, l. 2013. melting glaciers and ice patches in swedish lapland provide new insights into the holocene arboreal history. geo-öko 33, 121-146. kullman, l. & öberg, l. 2015. new aspects of high-mountainpalaeobiogeography: a synthesis of data from forefields of receding glaciers and ice patches in the tärna and kebnekaise mountains, swedish lapland. arctic 68(2), 141-152, kullman, l. & öberg, l. 2019. smältandeglaciärer – fornatidersklimat, trädochskogar. förlagbod, stockholm. laaksonen, k. 1976. the dependence of mean air temperature upon latitude and altitude in fennoscandia. annalesacademiaescientiarumfennicae a3 199, 1-19. lundqvist, j. 1969. beskrivningtilljordartskartaöverjämtlandslän. sverigesgeologiskaundersökning ser. ca 4, 1418, lundqvist, j. 1986. late weichselian glaciation and deglaciation in scandinavia, quaternary science reviews 5, 269-292. lundqvist, j, 1994. inlandsisensavsmältning. in: bergochjord. sverigesnationalatlas. braböcker, höganäs, pp, 124-131. luoto, t.p., kaukolehto, m., weckström, j., korhola, a. &väliranta, m. 2014. new evidence of warm earlyholocene summers in subarctic finland based on an enhanced regional chironomid-based temperature calibration model. quaternary research 81 (1), 50-62. moe, d. 1970. the post-glacial immigration of piceaabies into fennoscandia. botaniskanotiser 123, 61-66. mörner, n.a., solheim, j.-e., humlum, o. &pedersen, s.i. 2020. changes in barents sea ice edge positions in the last 440 years: a review of possible driving forces. international journal of astronomy and astrophysics 10, 97-164. nesje, a., pilø, l.h., finstad, e. and 7 others. 2011. the climatic significance of artefacts related to prehistoric reindeer hunting exposed by melting ice patches in southern norway. the holocene 22(4), 485-496. nicolussi, k. &patzelt, g. 2000. discovery of early holocene wood and peat on the forefield of the pasterze glacier, eastern alps, austria. the holocene 10, 191-199. öberg, l. & kullman, l 2011. recent glacier recession-a new source of postglacial treeline and climate history in the swedish scandes. landscape online 26, 1-38. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset parducci, l.,jørgensen, t.,tollefsrud, m.m and 22 others. glacial survival of boreal trees in northern scandinavia. science 355, 1083-1086. påsse, t. &andersson, l. 2005. shore-level displacement in fennoscandia calculated from empirical data. geologiskaföreningen i stockholmsförhandlingar 127, 253-268. paus, a. 2010. vegetation and environment of the rødalen alpine area, central norway, with emphasis on the early holocene. vegetation history and archaeobotany 19, 29-51 paus, a. 2013. human impact, soil erosion, and vegetation response lags to climate changes: challenges for the mid-scandinavian pollen-based transfer-function temperature reconstructions. vegetation history and archaeobotany 22, 269-284. paus, a., velle, g. & berge, j. 2011. the lateglacial and early holocene vegetation and environment in the dovre mountains, central norway, as signalled in two lateglacialnunatak lakes. quaternary science reviews 29,1780-1793. paus, a. &haugland, v. 2017. earlyto mid-holocene forest-line and climate dynamics in southern scandes mountains inferred from contrasting megafossil and pollen data. theholocene 27, 361-383. schenk, f., väliranta, m. &muschitiello, f. and 7 others2018. warm summers during the younger dryas cold reversal. nature communications 9, 1634. schlüchter, c. &jörin, u. 2004. holzundtorffundealsklimaindikatoren. alpenohnegletscher. die alpen 2004(6), 34-47. segerström, u. & von stedingk, h. 2003. early-holocene spruce, piceaabies (l.) karst., in west central sweden as revealed by pollen analysis. the holocene 13, 897-906. seppä. h., alenius, t., bradshaw, r., giesecke, t., heikkilä m. &muukkonen, p. 2009. invasion of norway spruce (piceaabies) and the rise of the boreal ecosystem in fennoscandia. journal of ecology 97, 629640. smith, h. 1920. vegetationenochdessutvecklingshistoria i detcentralsvenskahögfjällområdet. almqvist&wiksells, uppsala. väliranta, m. kaakinen, a., kuhry, p., kulti, s., salonen, j.s &seppä, h. 2011. scattered late-glacial and early holocene tree populations as dispersal nuclei for forest development in north-eastern european russia. journal of biogeography 38, 922-932. väliranta, m., salonen, j.s., heikkilä, and 10 others 2015. plant macrofossil evidence for an early onset of the holocene summer thermal maximum in northernmost europe. nature communications 6. doi: 10.1038/ncomms7809. zahle, r., huang, y.-t., bigler, c., wood, j.r., dalén, l., wang, x.-r., segerström, u. &klaminder, j. 2018. growth of plants on the late weichselian ice-sheet during greenland interstadial-1? quaternarysciencereviews 185, 222-239. mailto:topacademicjournals@gmail.com microsoft word 1.docx academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 83 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the need for further research into the transmission of influenza a viruses between migratory waterfowl and domestic ducks janet marie williams and robert michael brown university of texas at san antonio abstract: migratory waterfowl are the natural reservoir and source point for influenza viruses. artificial water ponds in rural and urban communities are potential sites of the human-animal interface for influenza a virus (iav). this paper reviews the literature on the transmission of iav between migratory waterfowl and domestic ducks in community ponds, and the potential for this to lead to human infection. keywords: influenza a virus (iav), migratory waterfowl, domestic ducks, community ponds, human infection, transmission introduction and background numerous research studies have indicated that migratory waterfowl are the natural reservoir and a source point for influenza viruses. artificial water ponds in rural and urban communities are potential sites of the humananimal interface for iav. webster, bean, gorman, chambers, and kawaoka (1992) described this human-animal interface with the example of domestic ducks in community ponds attracting migratory waterfowl. the migratory waterfowl introduce influenza virus to that community’s water pond from fecal contamination. the contaminated community water pond now becomes a potential source of influenza virus to both humans and animals. influenza disease emergence data are collected year-round, but economic strain on global public health to prevent and treat human influenza outbreaks has been enormous. therefore, it is imperative to identify potential sources of the virus to help minimize outbreak occurrence. statement of the problem there are gaps in knowledge about the association between molecular structure, epidemiologic and clinical characteristics, and the impact of ecological and other contextual aspects of iav. gaps in understanding the role of the physical and biogeochemical environment as an integral part of the iav transmission also exist (lang et al., 2008).more importantly, gaps in knowledge about the burden of iav in rural and urban community settings remain present. the problem was that public health science professionals have been battling emerging human influenza diseases with tactile and reactionary methods because there was a lack of knowledge and data at the human-animal interface. the purpose of this baseline study of the proportion of iav in urban and rural community settings was to provide knowledge and biological data of significant interest at the human-animal interface. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 84 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset emerging influenza viruses have continued to challenge public health officials. influenza viral infections appear with such regular annual frequency that it has been common to refer to the phenomenon as flu season or seasonal flu. however, pandemic influenza events have not been regular or predictable. taubenberger and morens (2006) identified and provided a brief synopsis of 13 pandemic events between 1510 and 1978.wali and music (2011) provided a summary of public health outcomes of nine u.s. influenza epidemics that occurred between the period 1972 to 1973 through 1991 to 1992.keeler (2011) provided a brief history of influenza pandemics from the time of discovery of the influenza virus through the last decade. further, keeler notably identified the sharp increase in public awareness of influenza and the potential human health threat of the virus. the outcomes of this study and detection of iav along the eastern pacific flyway were in alignment with the world health organization (2011) description of the human-animal interface as a complex juncture at which new paradigms are emerging. austin and hinshaw (1984) suggested that surveillance of healthy ducks and the aquatic environment they frequent may be of significant interest to monitoring and controlling iav. this research study is a model that can be modified to monitor iav in the aquatic environment. purpose of the study in this study, the proportion and probability of the presence of iav were investigated in recirculating artificial ponds in rural and urban geographical locations. rural ponds were viewed as one population and urban ponds as another population. the dependent agent variables were iav. the research question was as follows: is there a difference in the burden of iav in rural ponds compared to urban ponds? definition of terms several not commonly used terms-outside of the topic of influenza-are necessary for this research study. the manuscript by reid, taubenberger, and fanning (2004) includes definition of these terms. antigenic drift: minor changes in viral antigens due to gradual accumulation of mutations over time. antigenic shift: sudden change in viral antigens due to acquisition of one or more novel surface-protein-encoding genes by the process of reassortment. m gene sequence: the membrane protein (m) gene of iav is 1,027 nucleotides long and encodes two proteins, m1 and m2. m1 protein is the most abundant protein in the influenza a virus viron (webster et al., 1992). reassortment: due to the segmented nature of the iav genome (eight individual rna segments), influenza viruses can undergo a process of genetic reassortment to produce new variant strains of virus. in a cell infected with two different iav strains, gene segments from each can be packaged into viable hybrid virus strains. subtype: a designation for iav describing the antigenic group to which the two dominant surface glycoprotein’s — haemagglutinin (ha) and neuraminidase (na) — belong, written in the form hxnx, wherein one of the 16 possible has and one of the nine possible nas is listed, for example, h1n1 or h3n2. these terms are necessary and used throughout this study for clarity. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 85 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assumptions and limitations there are several assumptions about iav that are believed, but cannot be demonstrated to be true. firstly, the unique and problematic property of iav to evade hosts immune responses. secondly, the phenomena of humananimal transmission are not well understood. it is possible the ability to evade host immune responses and the humananimal transmission are the evolutionary traits that give iav a “natural fluid” presence resulting in seasonal outbreaks. keeler (2011) and others asserted the emergence of novel iav through antigenic drift or antigenic shift can result in significant increases in morbidity and mortality during any given influenza season. the outcome of antigenic drift or antigenic shift are routinely identified, however the mechanism of the processes are insofar only theorized. a pandemic is the outbreak of infection, arising in a specific geographical area and spreads throughout the world resulting in a high percentage of infected individuals and resulting in increased mortality rates (potter, 2001).it has been assumed that pandemics may be caused by a new iav subtypes. the new iav subtype may have an ha of which is not related to that of influenza viruses circulating immediately before the outbreak, and could not have arisen from those viruses by mutation (potter, 2001).the 1918 spanish flu is assumed to be caused by a “new iav” subtype. investigation into the influenza virus responsible for the 1918 spanish flu has not yet been fully discovered. investigation into the molecular mechanisms of iav is prominent in current literature. this may be due to recent advances in molecular and genetic sciences. artificial water ponds in rural and urban communities are potential sites of the human-animal interface. the investigation of the burden of iav in artificial rural and urban ponds may be of significant interest to the scientific community. the intent of this study was to investigate the burden of iav in artificial reticulating water ponds in the geographic locations of rural and urban californian communities. the geographical sampling region for rural and urban ponds was the eastern pacific flyway for migratory birds in california. for this study, it was necessary to make the assumption that artificial water ponds in rural and urban communities are sites of the human-animal interface because of fecal shedding and contamination from iav infected waterfowl (anseriformes) and shorebirds (charadriiformes).the primary goal of the laboratory analysis was to isolate and investigate iav in samples collected from water ponds in rural and urban californian communities. there are two threats to the external validity of this study. the first threat to external validity is centered to the theoretical framework of this study. the theoretical framework for this study were based on the hypotheses proposed by webster et al. (1992) and others that (a) migratory waterfowl are the natural reserve of influenza viruses, and (b) water-borne transmission of influenza virus occurs between migratory waterfowl and domestic waterfowl. the inclusion criteria of the study population were artificial recalculating water ponds in the geographic locations of rural and urban californian communities. the geographical area was the state boundaries of california. thus, the findings of this are limited to geographical locations along the migratory flyways of the waterfowl within the boundaries of california. to address this threat to the external validity of this study, the sampling and data analysis plan are presented in a fashion so the study may be reproduced accurately by others using the same or different geographical locations. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 86 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the second threat to external validity is a result of the inclusion criteria. recirculation artificial water ponds require mechanical equipment for recirculation. this study does not include the type or design of the mechanical equipment used for recirculation as an independent variable. thus, the mechanical equipment used for recirculation cannot be evaluated as a mediator or moderator of the outcome variables of this study. however, estimated surface area of the recirculating artificial water ponds as an independent variable may be of significant interest to future studies seeking to investigate factors that associate to the burden of iav at the humananimal interface in communities. the primary data collection of study is heavily weighted by laboratory instrumentation and molecular analysis. there are two threats to the internal validity of this study: instrumentation and laboratory assays. firstly, inaccuracy of the instrument used for this study may systematically alter the data. secondly, inaccuracy of the laboratory assays may fail to accurately detect iav. to address the possible inaccuracy of the instrumentation, the same instruments were used on all samples. thus, errors, if identified, may be corrected across all samples equally. to address the possible inaccuracy of the laboratory assays, positive and negative control samples were to be processed simultaneously as study samples. the positive control for iav was not obtained. the negative control used for iav was sterile normal saline. threats to statistical conclusion validity have not been identified. literature review history of influenza surveillance in 1947, at the 4th international congress for microbiology held in copenhagen, a group of virologist forwarded a recommendation to the interim commission of the world health organization an international program be initiated for influenza surveillance (hampson, 1997). the world health organization global influenza programme was established later that year (fleming, van der velden, & paget, 2003). the 1947 influenza surveillance control programme is the oldest disease control program at the world health organization (world health organization, 2005). the world health organization stated the creation of the 1947 influenza surveillance control programme resulted from two concerns: first, the inevitable recurrence, at unpredictable intervals, of highly disruptive pandemics; and second, the significant health and economic impact of seasonal epidemics, which occur nearly every year (p. 34).hampson (1997) opinioned the objectives of the 1947 influenza surveillance control programme as: to gain an understanding of the epidemiology of influenza, and to promptly isolate influenza viruses from new outbreaks and distribute them for vaccine production (p. s8).within four years of creation, the 1947 influenza surveillance control programme developed into a network of 60 laboratories across 40 countries. the influenza surveillance control programme became the who global influenza surveillance network consisting of 113 national influenza centers located in 84 countries (world health organization, 2005).following the adoption by the world health organization of the pandemic influenza preparedness framework in may 2011, the global influenza surveillance network was changed to global influenza surveillance and response system. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 87 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the centers for disease control and prevention and the european influenza surveillance scheme (eiss) collaborate with the who global influenza surveillance and response system to monitor the evolution of influenza viruses and provides recommendations in various disciplines including laboratory diagnostics, vaccines, antiviral susceptibility and risk assessment (world health organization, 2013). origin of influenza (china) the literature suggests china, with its abundance of live poultry and swine markets, maybe the epicenter of novel influenza viruses. wan et al. (2005) proclaimed that southern china has been shown to be the avian influenza virus pool for flu outbreaks in history including h2n2 (1957), h3n2 (1968), h5n1 (1997 & 2003), and h9n2 (1999).webster et al. (1992) noted historical records and the appearance of the asian, hong kong, and russian pandemic strains of influenza virus in china suggest the majority of pandemics of human influenza since about 1850 have originated in china. perez-ramirez et al. (2011) described how large parts of asia support high densities of humans, backyard poultry (ducks, geese, and chickens), pigs, and wild birds. these high density areas provide opportunities for close interaction between influenza reservoir animals and create a unique environment for influenza evolution (perezramirez et al., 2011).these unique environments may be considered an expansion of the mixing vessel theory; whereas these high density areas may be identified as “mixing vessel environments”. migratory waterfowl (vector for global distribution) austin and hinshaw (1984) investigated feral duck species as a source of transmission of iav and paramyxoviruses. the researchers collected swab samples from tracheal and cloacae from different species of feral ducks (austin & hinshaw, 1984). austin and hinshaw and were able to identify several viral strains of iav. additionally, austin and hinshaw asserted the alterations of influenza viral strains occur due to antigenic drift at point mutations and antigenic shift is caused by genetic reassortment. the authors contended it was possible these alterations occurred in the intestinal tract of ducks (austin & hinshaw, 1984).this article provides support to the hypothesis that migratory ducks are a source point for influenza viruses. therefore, surveillance of healthy ducks and the aquatic environment they frequent may be of significant interest to monitoring and controlling iav. as previously stated, the literature suggests novel influenza viruses originate in the southern china region where migratory waterfowl become infected. infected asymptomatic migratory waterfowl may transport the novel influenza viruses in their intestinal tracts to the wetland breeding grounds of alaska and siberia. the waterborne transmission of the influenza viruses to new hosts (migratory waterfowl from northern and southern american regions) may occur at these alaskan and siberian wetland breeding grounds. the new host(s) may act as a mixing vessel for influenza viruses. this may result in an antigenic shift or antigenic drift of influenza viruses resulting in novel strains. infected asymptomatic migratory waterfowl may then transport these influenza virus strains along the eastern pacific flyway for migratory birds. this process provides a possible explanation for the global distribution of novel influenza strains and further supports the necessity of influenza virus surveillance at the human-animal interface. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 88 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset water analysis water analysis has been an important scientific approach to understanding the epidemiological triangle model of influenza viral diseases. in the early study by cumming (1919), a case-control approach was used to better understand the transmission and infectivity of the causitive agent of influenza-pneumonia. the findings of cumming study suggested the agent was the influenza-pneumonia organism, the route of transmission was contaminated eating utensils, and aquatic dishwashing was the environment. webster et al. (1992) asserted waterborne transmission of influenza viruses occurs due to the viral shedding in the fecal material of waterfowl (anseriforms) and shorebirds (charadriiformes). van dalen et al. (2010) investigated waterborne transmission of influenza a h4n6 in mallards (anas platyyrhychos) in a controlled laboratory environment. lang et al. (2008) collected and analyzed sediment samples from three ponds in the creamer’s field migratory waterfowl refuge, alaska, a location used by a wide variety of migratory waterfowl. the sediment samples were collected using a time-series approach and analyzed for iav rna using reverse transcription-polymerase chain reaction (rt-pcr) methodologies (lang et al., 2008). zhang et al. (2006) collected and analyzed samples of ice or water from three northeastern siberian lakes in the koluma river region. the samples were analyzed for the presence of iav using reverse transcription-polymerase chain reaction (rtpcr) methodologies (zhang et al., 2006).hinshaw et al. (1980) collected samples from waterfowl, unconcentrated lake water, and feces from lake shores near vermillion, alberta, canada. these samples were used to isolate influenza viruses and to investigate whether influenza viruses continually circulate or whether the same or different strains are present from year to year (hinshaw et al., 1980). methodology research design the epidemiological triangle provided framework for the primary data collected. the epidemiological triangle has three vertices: host, agent, and environment. the host is the organism harboring the disease. for influenza disease, the reservoir hosts are migratory waterfowl and shorebirds (franklin et al., 2011).the agents are the iav. the environments are the natural and artificial habitats where the hosts are found. the independent environmental variables of this study were the geographical locations of the artificial water ponds in either a rural or urban community. the dependent agent variables were iav.iav data included detection for m gene sequence by real time rt-pcr using world health organization recommended primer sequences. sampling methods and procedures the study method was quantitative using a cross-sectional design. a convenience sampling approach was used. the geographical area was the state boundaries of california. equal sample sizes from rural and urban communities were attempted. a representative sampling from each of the 21 counties considered rural areas, and 37 counties considered metropolitan and not rural in california by california business and professions code section 19986(l) were attempted. the inclusion criteria of the study population were artificial recirculation water ponds in the geographic locations of rural and urban communities. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 89 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset water sampling (pre analytical phase) water samples were collected as previously published in the u.s.epa field sampling guidance document #1225.a dip sampler for water collection was used. a dip sampler is useful for situations where a sample is to be recovered from an outfall pipe or along a pond bank where direct access is limited. the long handle on such a device allows access from a discrete location so as not to disturb wildlife (u.s. environmental protection agency, 1999).the water volume per sample was 200 ml. other researchers have collected 200 ml volume water samples for influenza studies (zhang et al., 2011). sample preparation (pre analytical phase) sample integrity was maintained until received in the laboratory for processing. sample identification was maintained throughout the laboratory testing. samples were filtered using millipore durapore 0.22 µm filters to remove particulate matter and other suspended contaminates. the filtered sample were poured into 250 ml centrifuge tubes and concentrated at 10,000 rpm for 20 minutes at 4°c using a sorvall sl-1500 super-lite centrifuge rotor. 100 µl of rna later rna stabilizer reagent (qiagen n.v.) was added to 100 µl of the concentrated pond water sample in a separate polypropylene micro vial for viral rna extraction. evers et al. (2007) studied the commercial preservative rna later (qiagen n.v.) by evaluating against the current method of cryo-freezing, and ethanol preservatives for iav samples. from the findings of the evers et al. study, the authors asserted the commercial preservative rna later held at ambient temperatures might be useful for the identification of iav in samples collected from infected waterfowl. real time rt-pcr (analytical phase) reverse transcriptase polymerase chain reaction (rt-pcr) is a powerful technique for the identification of influenza virus genomes (world health organization, 2007). a constellation of studies have targeted the m gene sequence of the iav genome by rt-pcr as an indicator of iav positivity (harmon et al. 2010; lee et al., 2012; magnard et al.,1999; perez-ramırez, et al., 2012).during the analytical phase of this study real time rt-pcr technique was utilized. using real time rt-pcr allows for the detection of products as amplification is ongoing, allowing quantification (world health organization, 2007).the analytical phase was conducted following world health organization real-time rt-pcr protocol 2 for iav (h5n1) detection. data collection and analysis the primary data analysis was a cross-sectional approach comparing proportions recirculation artificial ponds in rural and urban geographical locations. the independent variable was: geographic community location (rural or urban). the dependent variable was: iav detection by real time rt-pcr. the statistical analysis software was ibm spss statistics 21 and microsoft office excel 2007. geographical graphing and mapping software was google earth. data integrity was maintained by recording data and observations with ink into field notebook and laboratory notebook. hand written entries were transferred or transcribed to microsoft office excel 2007 spreadsheets. all electronic data had digital backup and was password protected. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 90 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset credibility and validity credibility is important to uphold society’s trust that scientific research results are an honest and accurate reflection of a researcher’s work (national academy of sciences, national academy of engineering, and institute of medicine of the national academies, 2010). the materials and methods of this environmental baseline research study were built on the research of others. environmental water sampling underscored the research design of this study. therefore, the research adhered to the code of ethics and standards of practice for environmental professionals. the objectives of environmental professionals are to conduct their personal and professional lives and activities in an ethical manner (national association of environmental professionals, n.d). findings evaluation of research data artificial pond water samples were collected from 14 of the 21 counties considered rural areas, and from 25 of the 37 counties considered metropolitan and not rural in california by california business and professions code section19986(l). urban counties’ pond water samples [nurban = 100] were collected from 25 of the 37 counties considered metropolitan and not. rural counties’ pond water samples [nrural=82] were collected from 14ofthe21 counties considered rural and not metropolitan. pond water samples were verified for their content of iav genome by real time rt-pcr targeting the m gene sequence. the real time rt-pcr m gene assay was conducted using a bio-rad cfx96 touch real time pcr detection system (biorad, hercules, california) instrument and utilized two fluorescent dyes: fam and hex. the analysis software used was bio-rad cfx manager 3.1. the software setting was: end cycles to average [5] and percent of range [10.0]. the results for the fam fluorophore were: [lowest rfu value = -3.71], [highest rfu value = 3.41], [negative control average = -0.453], and [cut off value = -0.0668]. the number of statewide samples [n = 182] called (+) positive using fam [nfam = 45, 45/182 = 24.7%]. the results for the hex fluorophore were: [lowest rfu value = -1.93], [highest rfu value = 1.46], [negative control average = 1.42], and [cut off value = 1.42].the number of statewide samples [n = 182] called (+) positive using hex [nhex = 1, 1/182 = 0.5%].the number of statewide samples [n = 182] verified for their content of iav genome by real time rt-pcr targeting the m gene sequence is [n = 45] (see figure 1.).the confidence interval formula for a proportion is commonly known as: ci = p ± z α/2 × √[ (p × q) / n] , (x, n – x ≥ 5), where p = x / n, q = 1 p, α = 1 (confidence level/100) x = frequency, n = sample size, and z α/2 = z-table value. applying the data values of this study into the confidence interval formula the proportion of the overall statewide samples [n = 182] called (+) positive for the iav m gene sequence [n = 45] is p = 0.247, 95% ci [0.185, 0.310].the effect size index cohen’s g is the departure from p = 0.50 (cohen, 1988).thus, the non directional calculation for cohen’s g is [g = |p – 0.50|].for the overall statewide samples, the calculation of cohen’s g is [g mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 91 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset = |0.247 – 0.50| = 0.253]; a large effect size (cohen, 1988). using g*power 3.1.5, the post hoc computed power = 0.999 (two tailed). urban samples assayed by real time rt-pcr the number of urban county samples [nurban = 100] called (+) positive using fam [nfam = 36, 36/100 = 36.0%].the number of samples [nurban = 100] called (+) positive using hex [nhex = 1, 1/100 = 1.0%].the number of urban county samples [nurban = 100] verified for their content of iav genome by real time rt-pcr targeting the m gene sequence is [n = 36].applying the confidence interval formula for a proportion: ci = p ± z α/2 × √[ (p × q) / n] , (x, n – x ≥ 5), where p = x / n, q = 1 p, α = 1 (confidence level/100) x = frequency, n = sample size, and z α/2 = z-table value, the proportion of the urban counties’ samples [nurban = 100] called (+) positive for the iav m gene sequence [n = 36] is p = 0.36, 95% ci [0.266, 0.454]. the effect size index cohen’s g is the departure from p = 0.50 (cohen, 1988).thus, the non directional calculation for cohen’s g is [g = |p – 0.50|].for the urban counties’ samples, the calculation of cohen’s g is [g = |0.36 – 0.50| = 0.14]; a medium effect size (cohen, 1988).using g*power 3.1.5, the post hoc computed power = 0.768 (two tailed) rural samples assayed by real time rt-pcr the number of rural counties’ samples [nrural = 82] called (+) positive using fam [nfam = 7, 7/82 = 8.5%].the number of samples [nrural = 82] called (+) positive using hex [nhex = 2, 2/82 = 2.4%].the number of rural counties’ samples [nrural = 82] verified for their content of iav genome by real time rt-pcr targeting the m gene sequence is [n = 9].applying the confidence interval formula for a proportions: ci = p ± z α/2 × √[ (p × q) / n] , (x, n – x ≥ 5), where p = x / n, q = 1 p, α = 1 (confidence level/100) x = frequency, n = sample size, and z α/2 = ztable value, the proportion of the rural counties’ samples [nrural = 82] called (+) positive for the iav m gene sequence [n = 9] is p = 0.11, 95% ci [0.042, 0.177]. the effect size index cohen’s g is the departure from p = 0.50 (cohen, 1988).thus, the non directional calculation for cohen’s g is [g = |p – 0.50|].for the rural counties’ samples, the calculation of cohen’s g is [g = |0.11 – 0.50| = 0.39]; a large effect size (cohen, 1988).using g*power 3.1.5, the post hoc computed power = 1.000 (two tailed). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 92 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: statewide samples verified for their content of iav genome. google earth map of california showing statewide pond water samples verified for their content of iav genome by real time rt-pcr targeting the m gene sequence. [red icon = (+) positive for m gene sequence and green icon = (-) negative for m gene sequence]. analysis of relevant research data in this study the proportion and probability of the presence of iav was investigated in recirculation artificial ponds in rural and urban geographical locations. rural ponds were viewed as one population and urban ponds as another population. the dependent agent variables are iav.iav data included: detection for m gene by real time rt-pcr using world health organization recommended primer sequences. examination of the research question the proportion of the urban counties’ samples [nurban = 100] called (+) positive for the iav m gene sequence [nu = 36] is pu = 0.36, 95% ci [0.266, 0.454]. this value is numerically larger than the proportion of the rural counties’ samples [nrural = 82] called (+) positive for the iav m gene sequence [nr = 9] is pr = 0.11, 95% ci [0.042, 0.177].it is commonly accepted the two-sided 100 (1 α) % ci for the difference between two proportions of unequal sample size is of the form: (^p1 – ^p2 )± z1 – α/2 √ [ (^p1 (1 – ^p1) / n1 ) + (^p2 ( 1 – ^p2) / n2 ) ]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 93 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset for this analysis; [^p1 = nu / nurban], [^p2 = nr / nrural], and [z1 – α/2 = 1.96].the calculated difference in the proportion of urban counties’ samples called (+) positive for the iav m gene sequence to rural counties’ samples called (+) positive for the iav m gene sequence is directionally towards urban counties’ samples [(^p1 – ^p2= 0.2502, 95% ci (0.1278, 0.3604), rd = 0.2502, 95% ci (0.1337, 0.3668), rr = 3.28, 95% ci (1.83, 7.79), or = 4.563, 95% ci (2.042, 10.193)]. the effect size index of the difference between two proportions is cohen’s h. cohen’s h is the calculated difference between the arcsine transformations of the proportions (p) of the populations (cohen, 1988).thus, cohen’s h = |φ1 – φ2| where φ = 2 arcsine √(p).the calculated effect size index for the difference in the proportion of urban counties’ samples to rural counties’ samples called (+) positive for the iav m gene sequence is cohen’s h = | (2 arcsine √(pu)) – (2 arcsine √(pr)) | = | (2 arcsine √(0.36)) – (2 arcsine √(0.11)) | = | 1.287 – 0.676 | = 0.611; a large effect size (cohen, 1988).using g*power 3.1.5, the post hoc computed power = 0.979 (two tailed) and actual α = 0.038. summary and implications summary this research study has been an investigation into the proportion of iav in artificial suburban neighborhood water ponds. no known research has analyzed the proportion and persistence of influenza viruses in these aquatic habitats. to investigate the proportion of iav in recirculation artificial ponds, 182 pond water samples were collected from a representative sampling from 14 counties considered rural areas (nrural = 82), and 25 counties considered metropolitan and not rural (nurban = 100) in california by california business and professions code section 19986(l) was achieved. field research data and laboratory data were transcribed to a microsoft office excel 2007 spreadsheet and statistically analyzed to answer the research question of this study. the analysis of the proportion of iav in rural and urban water ponds favored the greater burden of iav in urban community ponds over rural community ponds [(^p1 – ^p2= 0.2502, 95% ci (0.1278, 0.3604), cohen’s h = 0.611, power = 0.979, actual α = 0.038]. implications the potential impact of this study can be recognized at the international level, the national and state level, the population level, and at the individual level. the results show that artificial water ponds in communities can be sources of iav.it is commonly known that iav can result in a zoonotic disease. infectivity and sub typing of isolated iav may identify strains previously known capable for animal-human transmission, or human-human transmission. as sources of iav, the artificial water ponds in communities can be used to increase iav surveillance and monitoring at the human-animal interface, expand and improve upon the iav strain library for vaccine development, and may bring greater awareness to the individual, and thus, greater perceived susceptibility to iav mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 94 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset infection leading to improved vaccination rates. international surveillance and monitoring of influenza viruses is a current global challenge. references austin, f. j., & hinshaw, v. s. (1984). the isolation of influenza a viruses and paramyxo viruses from feral ducks in new zealand. australian journal of experimental biology and medical science, 62, 355-360. cohen, j. (1988). statistical power analysis for the behavioral sciences (2nd ed.). new york, new york: taylor & francis group, llc. cumming, j. g. (1919). influenza-pneumonia as influenced by dishwashing in three hundred and seventy public institutions. american journal of public health, 9(11), 849-853. evers, d. l., slemons, r. d., & taubenberger, j. k. (2007). effect of preservative on recoverable rt-pcr amplicon length from influenza a virus in bird feces. avian diseases, 51(4), 965-968. fleming, d. m., van der velden, j., & paget, w. j. (2003). the evolution of influenza surveillance in europe and prospects for the next 10 years. vaccine, 21, 17491753. franklin, a., van dalen, k. k., & huyvaert, k. (2011). avian influenza virus in aquatic environments an ecological perspective. in s. k. majumdar, f. j. brenner, j. e. huffman, r. g. mclean, a. i. panah, p. j. pietrobon, et al. (eds.), pandemic influenza viruses: science, surveillance, and public health (pp. 59-72). alpha, nj: pennsylvania academy of science. hampson, a. w. (1997). surveillance for pandemic influenza. the journal of infectious diseases, 176(suppl. 1), s8-s13. harmon, k., bower, l., kim, w.-i., pentella, m., & yoon, k.-j. (2010). a matrix gene–based multiplex real-time rt-pcr for detection and differentiation of 2009 pandemic h1n1 and other influenza a viruses in north america. influenza and other respiratory viruses, 4(6), 405-410. hinshaw, v. s., webster, r. g., & turner, b. (1980). the perpetuation of orthomyxoviruses and paramyxoviruses in canadian waterfowl. canadian journal of microbiology, 26, 622-629. ito, t., okazaki, k., kawaoka, y., takada, a., webster, r. g., & kida, h. (1995). perpetuation of influenza a viruses in alaskan waterfowl reservoirs. archives of virology, 140, 1163-1172. keeler, s. p. (2011). history of human influenza. in s. k. majumdar, f. j. brenner, j. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 95 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset e. huffman, r. g. mclean, a. i. panah, p. j. pietrobon, et al. (eds.), pandemic influenza viruses: science, surveillance, and public health (pp. 12-28). alpha, nj: pennsylvania academy of science. lang, a. s., kelly, a., &runstadler, j. a. (2008). prevalence and diversity of avian influenza viruses in environmental reservoirs. journal of general virology, 89, 509-519. magnard, c., valette, m., aymard, m., & lina, b. (1999). comparison of two nested pcr, cell culture, and antigen detection for the diagnosis of upper respiratory tract infections due to influenza viruses. journal of medical virology, 59, 215-220. national academy of sciences, national academy of engineering, and institute of medicine of the national academies. (2010). on being a scientist: a guide to responsible conduct in research (3rd ed.). washington, d.c.: the national academies press. national association of environmental professionals. (n.d). code of ethics and standards of practice for environmental professionals. retrieved from http://www.naep.org/code-of-ethics perez-ramirez, e., de toledo, r., &feare, c. j. (2011). avian influenza in wild birds in europe, asia, and africa. in s. k. majumdar, f. j. brenner, j. e. huffman, r. g. mclean, a. i. panah, p. j. pietrobon, et al. (eds.), pandemic influenza viruses: science, surveillance, and public health (pp. 112-129). alpha, nj: pennsylvania academy of science. potter, c. w. (2001). a history of influenza. journal of applied microbiology, 91, 572-579. reid, a. h., taubenberger, j. k., & fanning, t. c. (2004). evidence of an absence: the genetic origins of the 1918 pandemic influenza virus. nature reviews: microbiology, 2, 909-914. taubenberger, j. k., &morens, d. m. (2006). 1918 influenza: the mother of all pandemics. emerging infectious diseases, 12(1), 15-22. vandalen, k. k., franklin, a. b., mooers, n. l., sullivan, h. j., & shriner, s. a. (2010). shedding light on avian influenza h4n6 infection in mallards: modes of transmission and implications for surveillance. doi:10.1371/journal.pone.0012851 wali, m., & music, s. (2011). seasonal and pandemic influenza: surveillance and vaccine management. in s. k. majumdar, f. j. brenner, j. e. huffman, r. g. mclean, a. i. panah, p. j. pietrobon, et al. (eds.), pandemic influenza viruses: science, surveillance, and public health (pp. 339-355). alpha, nj: pennsylvania academy of science. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 96 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wan, x. f., ren, t., luo, k. j., liao, m., zhang, g. h., chen, j. d., et al. (2005). genetic characterization of h5n1 avian influenza viruses isolated in southern china during the 2003–04 avian influenza outbreaks. archives of virology, 150, 1257-1266. webster, r. g., bean, w. j., gorman, o. t., chambers, t. m., &kawaoka, y. (1992). evolution and ecology of influenza a viruses. microbiological reviews, 56(1), 152-179. world health organization. (2005). avian influenza: assessing the pandemic threat. world health organization, global influenza programme. retrieved from http://www.who.int/influenza/en/ world health organization. (2007, august). recommendations and laboratory procedures for detection of avian influenza a(h5n1) virus in specimens from suspected human cases. retrieved from http://www.who.int/influenza/resources/documents/recailabtestsaug07.p df world health organization. (2011). influenza and other emerging zoonotic diseases at the human-animal interface. retrieved from http://www.fao.org/docrep/014/i1963e/i1963e00.htm world health organization. (2013). global influenza surveillance and response system(gisrs). retrieved from http://www.who.int/influenza/gisrs_laboratory/en/ zhang, h., xu, b., chen, q., chen, j., & chen, z. (2011). characterization of an h10n8 influenza virus isolated from dongting lake wetland. virology journal, 8(42), 1-9. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 58 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset plant maintenance strategy for improved production in the food and beverage industries onyejaka, chidi maurice department of engineering management, faculty of engineering, enugu state university of science and technology, enugu. doi: https://doi.org/ 10.5281/zenodo.12547983 abstract: the evaluation of plant maintenance methods for improved performance in the food and beverage industries was carried out using nigerian bottling company benin and owerri plants and bons industries limited enugu, nigeria. the study investigated to determine the maintenance approaches used in the food and beverage manufacturing industries and to evaluate the availability rate, performance rate, and quality rate of the manufacturing industry due to maintenance. records on maintenance activities on filler machines, packers, blow mold, monobloc (filler/capper/rinser) machines, and palletizers were collected using record forms from the logbook for a period of five years (2017 – 2021) and this serves as the primary data for the research. the worldclass overall equipment effectiveness (oee) mathematical model was used to evaluate the maintenance performance of each plant. in nigerian bottling company (nbc), the availability rate of the filler machine ranged from 93.0% 96.9%, the performance rate ranged from 66.2% 129.3% and the quality rate was 99.9% for all the years. for bones industries ltd, water production line, the availability rate of the monobloc machine ranged from 86.8% 95.8%, the performance rate ranged from 47.2% 96.1% while the quality rate ranged from 91.8% 93.7%. the maintenance methods/approaches used in nbc plants were preventive and usage while the maintenance methods/approaches used in bons industries equipment were preventive and condition-based maintenance. the availability rate, performance rate, and quality rate which are the parameters to evaluate equipment maintenance performance were better in nbc than in bons industries. the overall maintenance cost and cost per case are also better in nbc than that of bons about volume produced. this recommended that companies should carry out routine preventive maintenance and usage-based maintenance such as periodic machine overhauls since the better result was obtained when compared to preventive and condition-based. keywords: food and beverage industries, plant maintenance, production, strategy, food and beverage industries. 1.1 introduction maintenance is defined according to the european standard (alsyouf, 2004) as “the combination of all technical, administrative and managerial actions during the life cycle of an item intended to retain it in, or restore it to a state in which it can perform the required function”. it leads to high-quality and low-defect products, a safe and secure work environment, increased production speed, and the overall improvement of the performance of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 59 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset plant. to perform maximally, the machines have to be maintained. however, some view maintenance as a waste of resources whereas maintenance should be viewed as a profit center and not an avoidable expense (al-najjar et al., 2001; al-najjar and alsyouf, 2004). effective maintenance results in long-term profit and it has an impact on production and its operational aspects such as capacity, quality, costs, environment, and safety. in recent times, the machines used in manufacturing companies are automated compared to simple machines used before world war ii (alsyouf, 2007). reliability, availability, maintainability (ram), safety, quality, environment, and multiskilling are considered very important in current machines in use. nigeria is a populous developing country with a lot of economic challenges. it has undergone more than two economic recessions since 2016. this has led to the folding up of some companies. some that are still functional do not have maximum performance because of myriad factors. however, the demand for products by the teeming population of nigeria and competition among companies demands that the remaining companies perform maximally (mifdal et al., 2013). industrialization in nigeria seems to be at a crossroads given that these pursuits of the strategy would lead to more inefficient resource usage, intensified foreign exchange constraints, high cost, and balance of payment difficulties. this is paradoxical given that the industrial sector is theoretically at least expected to have the capacity to innovate and thus exude the dynamism that affects the other sectors of the economy. businesses in the nigerian manufacturing sector have tottered over the years due to a lack of adequate management commitment to timely funding of materials procurement coupled with unethical practices of some executives (oba, 2008). according to a survey carried out in 2010 by the manufacturers association of nigeria (man), 834 manufacturing companies shut down their operations in 2009 across the country due to high manufacturing costs created by exorbitant prices of raw materials and spare parts for machine maintenance among other reasons (adeloye, 2010). the few surviving manufacturing firms are faced with stiff competition in the current markets. this has led to the need for coming up with a better method of managing and measuring how material resources are utilized by various jobs or products and therefore be able to eliminate any wastage in the value chain. with the process of liberalization, there has been a drastic change in the market which has forced manufacturing companies to devise strategies to minimize production and equipment maintenance costs to remain competitive. today, there are dramatic evolutions in the market environment and every organization must strive to keep itself in business. major competition has shifted from the market to the production floor where manufacturing costs (including equipment maintenance costs) can be reduced and profitability boosted for firms to compete favorably. backed by advanced technology, firms are closely monitoring their manufacturing costs and embarking on efficient management of materials (ondiek, 2009). unfortunately, few studies exist yet on the productivity analysis of manufacturing firms for a developing economy such as nigeria. this study intends to fill this gap on mainly the equipment maintenance performance side which is huge, with the right maintenance strategy in place all these can be properly achieved. 1.2 statement of the problem mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 60 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset poor maintenance of machines and equipment is known to result in low productivity, low profit, and reduced efficiency/reliability of the machines. while these organizations are busy working out means of increasing productivity and enhancing their equipment performance, the problems continue to increase. it can be pointed out here that the results or implications of these are damaging. low productivity and poor equipment maintenance lead to unnecessary loss of huge amounts of money. these losses of money by these organizations cripple the economy of the nation. given the above-mentioned problems, it becomes obvious that there is a need to evaluate the plant maintenance strategy for improved production in the manufacturing firm in nigeria and also determine the equipment maintenance performances. hence, there is a need to evaluate the maintenance culture/strategy of the industries in developing countries like nigeria where resources are scarce. 1.3 aims and objective to evaluate the equipment maintenance strategy for improved performance in the food and beverage industries. research objectives 1. to determine the maintenance approaches used in the food and beverage manufacturing industries. 2. to evaluate the availability rate, performance rate, and quality rate of the manufacturing industry due to maintenance. 1.4 hypothesis of the study the following alternative hypotheses guided the study.  there are no maintenance approaches used in the food and beverage industries.  evaluation of the availability rate, performance rate, and quality rate of the manufacturing industry will not be improved due to equipment maintenance. 2.0 review of related literature 2.1 conceptual review maintenance maintenance is defined according to the european standard as “the combination of all technical, administrative and managerial actions during the life cycle of an item intended to retain it in, or restore it to a state in which it can perform the required function”. it leads to high-quality and low-defect products, a safe and secure work environment, increased production speed, and the overall improvement of the performance of the plant. equipment maintenance is any process used to keep a business's equipment in reliable working order. it may include routine upkeep as well as corrective repair work or procedures used by technicians to keep the machine in top shape. equipment may include mechanical assets, tools, heavy off-road vehicles, and computer systems. the need for maintenance is predicated on actual or impending failure – ideally, maintenance is performed to keep equipment and systems running efficiently for at least the design life of the component(s). maintenance strategy gives room for strategic maintenance decision making which involves selecting the right care and repair methodologies that maximize equipment life and performance for the least cost to the user. but to be able to make successful maintenance management strategy choices you must understand how equipment fails. when you know the equipment’s weaknesses and strengths you can care for it properly and get maximum mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 61 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset service from it at the least cost. we have different types of maintenance approaches/strategies which include preventive, corrective, predictive, condition-based, usage-based maintenance, etc. maintenance has had a tremendous impact on the company’s proficiency to optimize its production system to meet its long-term objectives. generally, a production system in which maintenance is not given attention may easily lead to the system producing defective products as a result of machine defects, (alsyouf, 2004). types of maintenance approaches the need for maintenance is predicated on actual or impending failure – ideally, maintenance is performed to keep equipment and systems running efficiently for at least the design life of the component (s). as such, the practical operation of a component is a time-based function. anytime we fail to perform maintenance activities intended by the equipment’s designer, we shorten the operating life of the equipment. but what options do we have? over the last 30 years, different approaches to how maintenance can be performed to ensure equipment reaches or exceeds its design life have been developed in the united states. in addition to waiting for a piece of equipment to fail (reactive maintenance), we can utilize preventive maintenance, predictive maintenance, or reliability-centered maintenance, (piotrowski, 2001). the strategies/approaches: • reactive maintenance: the moment the machine breaks down, it will be immediately fixed. • preventive maintenance: there will be a parts replacement schedule ahead of time before parts breakdown, usually at a regular interval. • usage-based maintenance: the parts are replaced when the machine has been used for a certain period before they break down. • condition-based maintenance: the parts are replaced when they seem to getting too worn out to continue functioning appropriately. • predictive maintenance: the historical data are utilized to make predictions about when a part will break and replace the parts based on these predictions before they break. this usually, but not always, utilizes artificial intelligence and machine learning. • prescriptive maintenance: this involves using advanced data analysis methods to do more than predict failure points, but instead provides hypothetical outcomes to choose the best action that can be taken before failure, safety hazards, and quality issues arise as well as the timing of implementation. using the right maintenance approach for manufacturing equipment gives room for better machine performance. however, we will go further to elaborate on the strategies/types of maintenance that are mostly used in manufacturing industries, (al-najjar, 1997; kelly, 1997; pintelon and gelders, 1992). availability rate: equipment availability is a metric used to measure the percentage of time a machine can be used. it is the amount of time in which a machine runs and is available for production. availability can also be called 'uptime', and it is one of the key metrics that give us insight into our production efficiency. machine availability, or uptime, is the total amount of time a machine runs versus the time it was scheduled to run. availability is the percentage of time a machine is in operation. the scheduled time is based on understanding mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 62 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset available capacity, having the raw materials on hand in appropriate quantities, and having the staff and sales orders required to run. downtime can slow or stop the machine during this scheduled time. total downtime includes preventive maintenance, changeovers, and other controlled, known variables. unplanned downtime means breakage, quality fallout, jams, or other unpredicted stoppages. for example, a machine could be scheduled to run for eight hours and only be active for six hours. in this case, the availability score for the machine is 75%. all manufacturing operations should measure availability and downtime, taking into account the duration and reason for downtime. however, if this is tracked by hand, it is likely to be highly inaccurate, severely delayed, and far less actionable. machine availability also referred to as uptime, is the total amount of time a machine runs versus the time it was scheduled to run. availability is a key figure to monitor when it comes to production planning. production capacity, delivery dates, expected breakdowns, and costing are determined from availability data, (waeyenbergh and pintelon, 2002; kumar, 1996). machine availability is calculated in the following way: availability = production run time planned production time 2.1.4 performance rate: performance, also known as process rate, measures the speed at which the workstation or machine processes units. it is also represented as a percentage of the ideal, with performance losses being caused by logistical problems, searching for tools, small stops, operator inefficiency, decreased speed of the machine, etc. performance = (total units x ideal cycle time) real run time quality rate: the quality rate is defined as the ratio between the yield produced and the total production quantity. for the calculation of the quality rate, the scrap quantity incurred must be recorded. this can be done, e.g., by manual input which is made directly at the machine terminal, or by comparing the total production volume recorded with the possibly existing weighing of the actual yield. quality is calculated by dividing the number of usable units produced by the total units stated. if an asset produces 12,000 units in a 12-hour production time frame, but 300 of them have defects that make them unusable, then the number of usable units is 11,700. therefore, the quality score would be 0.975 or 97.5%. quality takes into account manufactured parts that do not meet quality standards, including parts that need rework. remember, oee quality is similar to first pass yield, in that it defines good parts as parts that successfully pass through the manufacturing process the first time without needing any rework. quality is calculated as: quality = good count total count hence quality rate = good count x 100 total count improved performance mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 63 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset performance is the result of work and work behavior that has been achieved in completing the tasks and responsibilities given in a certain period. didier (2002) considers that performance is to "achieve the goals that you have given in convergence with the company guidelines” and that performance is not simply finding a product but rather is the result of a comparison result and objective. performance improvement is measuring the output of a particular business process or procedure, then modifying the process or procedure to increase the output, increase efficiency, or increase the effectiveness of the process or procedure. the primary goals of organizational improvement are to increase organizational effectiveness and efficiency to improve the ability of the organization to deliver goods and or services. a third area sometimes targeted for improvement is organizational efficacy, which involves the process of setting organizational goals and objectives. improving performance can pertain to various domains such as personal productivity, physical fitness, or even organizational efficiency. there are two main ways to improve performance: improving the measured attribute by using the performance platform more effectively, or by improving the measured attribute by modifying the performance platform, which in turn allows a given level of use to be more effective in producing the desired output. all companies strive for better performance since high performance means high competitiveness, which in turn generates more money. however, there are different ways to increase performance, depending on which viewpoint you choose to take, efforts to improve performance in manufacturing operations have been important since the start of the industrialization era, (kirkpatrick, 2006). food and beverage industries the food and beverage industry includes all the companies involved in transforming raw agricultural goods into consumer food products as well as processing, packaging, distribution, and retail, which are all included in the large, diverse food and beverage industry. due to their provision of necessary goods and services that support life and promote social and economic advancement, these industries are vital to both the global economy and human welfare. it does not cover raw food production, which falls into the closely related agriculture industry. this industry includes fresh food, packaged food, and beverages (both alcoholic and non-alcoholic). from food sold at the grocery store to cooked meals served at restaurants, institutions, and events, this industry serves a huge variety of retail outlets. the food and beverage industry is divided into two major segments, which are the production and the distribution of edible goods. as the world’s population grows, so does the demand for food and drink. but that’s not all. it’s one of the oldest industries on the planet, but still full of innovation. from new products to higher-volume, lowercost production techniques, this industry is always looking for new ways to produce the food consumers want at the best possible price. and vital equipment is there every step of the way. consumers want more than just food and drink for sustenance; their demands are now more health, ethically, and environmentally driven, (fao, 2018). 2.2 theoretical framework the systems theory this theory viewed the inputs/output models. the inputs are taken through processes to transform them into outputs. the outputs are compared with the objectives and feedback is sent to the inputs to enhance improvement mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 64 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of efficiency and productivity of the system (ludarig, 1968). he noted that maintenance management was the system, the inputs were labor, materials, spares, tools, information, and external services. the maintenance system processes these inputs into availability, maintainability, safety, and profits as the outputs. systems theory is a concept that originated from biology, economics, and engineering, which explores principles and laws that can be generalized across various systems (alter, 2007; dubrovsky, 2004). a system is a set of two or more elements where: the behavior of each element affects the behavior of the whole; the behavior of the elements and their effects on the whole are interdependent; and while subgroups of the elements all affect the behavior of the whole, none has an independent effect on it (skyttner, 1996). in other words, a system comprises subsystems whose inter-relationships and interdependence move toward equilibrium within the larger system (martinelli, 2001; steele, 2003). 2.3 empirical review foon and terziovski m (2014) conducted a study to evaluate the impact of operations and maintenance practices on power plant performance in australia and malaysia. the study aimed to examine the impact of operations and maintenance (o&m) practices, individually and collectively, on power plant performance. a survey research design was used for this study. the results revealed that the relationship between o&m practices and plant performance is significant and positive in a cross-sectional sense. maletic et al (2014) examined the role of preventive maintenance in improving a company’s competitiveness and efficiency in a slovenian textile company. this study aimed to discuss the potential improvement areas from the company's perspective and to examine maintenance impact on the company’s business. an empirical case study was utilized for this study. the results revealed that preventive maintenance practices and condition-based maintenance (cbm) approach represent the highest opportunity for improvement of organizational performance. oseghale (2014) conducted a study on the impact of maintenance strategies on the performance of industrial facilities in selected industrial estates in lagos state, nigeria. the study aimed to appraise the facilities and the maintenance management strategies employed in selected industrial estates in lagos state by identifying and examining facilities maintenance strategies, and determining their impact on the physical condition of the facilities. both quantitative and qualitative were employed for this research. the results revealed that there was no significant relationship between the types of maintenance strategies and the respondents’ level of satisfaction with the physical condition of their facilities. uforo et al, (2022) conducted a study to examine the relationship between maintenance management and organizational performance among selected manufacturing firms in akwa ibom state. the study aims to study the relationship between corrective maintenance, preventive maintenance, conditions-based maintenance, organizational culture, maintenance management, and organizational performance in manufacturing firms. a survey research design was adopted for this study. the results revealed that management has to provide the maintenance teams with maintenance management software to ensure proper intervention monitoring as well as smooth communication between technicians and other professionals to enhance business success. 3.0 methodology mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 65 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a retrospective study of performance evaluation of maintenance of nigerian bottling company ltd (coca-cola) benin, owerri plant, and bons industries limited, enugu from 2017 – 2021 (5 years) was adopted. logbooks, work orders, operating statistics, and production reports including target volume and actual volumes were assessed to obtain primary data. the study was carried out at nigeria bottling company ltd (nbc), benin plant, edo state, and nigerian bottling company ltd (nbc) owerri plant, imo state, nigeria. a record form containing questions on year of study, type of machine, type of maintenance, machine breakdown records, downtime incurred in each equipment, hours of operation, target amount of product, actual amount of product, quantity of defective product, cost of maintenance and major maintenance done on the lines were used. record analysis of relevant data was obtained from the company’s annual maintenance report and journals. data were analyzed using microsoft excel. the availability rate, performance rate, and quality rate were calculated using oee, the availability of the machine was further analyzed with a bar chart or pie chart, and the explanation was done to see how it affected equipment performance. also, the performance rate and the quality of the product produced by the machines were further analyzed using the bar chart and pie chart and the result was explained. the mathematical expressions below are used to obtain the actual values in percentages of these parameters (availability, performance, and quality rates): availability rate of the equipment = planned runtime-planned downtime x100 planned run time performance rate of the equipment = total actual amount of product x100 target amount of product quality rate of the equipment = processed quantity –defective quantity x100 processed quantity the total cost of maintenance and cost per case of each maintenance strategy were also analyzed to obtain the best method of maintenance for effective food and beverage production. the mathematical expression/formula below was used. preventive maintenance percentage cost = preventive maint. cost x100 total maintenance cost cost per case = preventive maint.cost total volume of product. usage based maintenance percentage cost = usage based maint. cost x100 total maintenance cost cost per case = usage based maint.cost total volume of product. this is done for the condition-based maintenance strategy used in this study. 4.0 data presentation and analysis 4.1 presentation of results this study was for a period of five years,s (year one: 2017; year two: 2018; year three: 2019; year four: 2020; years five: 2021) the filler machine – nbc benin plant. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 66 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4.1 shows that the filler machine – benin plant was purchased in 2008 and the type of maintenance approaches carried out were preventive and usage-based maintenance. the machine has a capacity of 1650cph – (cph: cases per hour). table 4.1: general information of the filler machine variables information name of machine filler year of purchase 2008 type of maintenance preventive and usage-based capacity of machine 1650cph table 4.2: data obtained from the company (nigerian bottling company (nbc) benin plant south-south) filler machine rgb variables 2017 2018 2019 2020 2021 total number of hours of breakdown per year(hours) 123.66 107.33 146.33 153.4 108.5 planned number of hours of operation per year(hours) 2386.67 2462.56 3626.02 2028.80 3481.41 number of hours of machine overtime per year 242 201 166 143 129 target amount of product per year (cases) 3,102,244 3,505,644 4,799,560 5,234,767 4,878,455 actual amount of product per year(cases) 3,230,017 3,794,995 6,207,177 3,467,081 5,543,752 quantity of defective products per year (cases) 4213 4983 5310 4643 4891 machine capacity (cph) 1650 1650 1650 1650 1650 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 67 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset calculations using the oee model for the filler equipment: the calculations in appendix 1 show the workings using the overall equipment effectiveness world-class model for evaluation of the availability rate, performance rate, and quality rate of the filler machine. the availability rate: table 4.3 shows that the availability rate of the filler machine ranges from 92.5% 97.0%. in 2017, it was 94.8%; 2018 (95.6%); 2019 (96.0%); 2020 (92.5%); 2021 (96.9%). however, it was highest in year five at 97.0% while least in year four at 92.4%. table 4.3: availability rate of the nbc filler machine – benin plant. year of study availability rate (%) year one (2017) 94.8 year two (2018) 95.6 year three(2019) 96.0 year four (2020) 92.5 year five (2021) 96.9 figure 4.1 shows the availability rate of the filler machine. the availability rate was highest in year five 96.9% while it was lowest in year four (93.0%) figure 4.1: availability rate of the filler machine from table 4.3 and also looking at figure 4.1, the availability rate is higher in year five than in year three despite the higher planned hours of operation for year three. this is because the availability rate of equipment is 95.0% 96.0% 96.0% 93.0% 96.9% 91% 92% 93% 94% 95% 96% 97% 98% year one year two year three year four year five a v a il a b il it y r a te (% ) year of study mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 68 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset considered about downtime incurred during operation and even the corresponding volume of product produced. for example looking (table 4.2) at the planned number of hours of operation in years three and four, that of year three is more but that does not make that year the highest in equipment(filler) availability due to downtime it incurred. this implies that a year with smaller planned hours of operation might turn out to be the year with the best availability of the equipment if the downtime or machine breakdown is reduced due to the maintenance strategy that may be applied. however, in this case, the actual hours of operation about the planned hour give a higher availability rate in year five. also when the machine breakdown is reduced with the corresponding reduced downtime, there is always a positive effect on the volume of product produced and all these are influenced by the type of maintenance strategy/method involved as can be seen in table 4.2 for year three (6,207,177) and year five (5,543,752). the performance rate: table 4.4 shows that the performance rate of the filler machine ranges from 66.2% 129.3%. in 2017, it was 104.1%; 2018 (108.3%); 2019 (109.3%); 2020 (66.2%); 2021 (113.6%). however, it was highest in year three with 129.3% while least in year four 66.2%. table 4.4: performance rate of the nbc filler machine – benin plant. year of study performance rate (%) year one (2017) 104.11% year two (2018) 108.25% year three(2019) 129.32% year four (2020) 66.23% year five (2021) 113.63% figure 4.2 shows that the performance rate was lowest in year four 2020 (66.2%) while it was highest in year three (129%). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 69 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4.2: performance rate of the filler machine. from figure 4.2, the bar chart, the performance rate was highest in year three (129.3%). this may be attributed to the complete year-round refit (quarterly overhaul) done on filler, the preventive maintenance was routinely carried out hence the equipment availability for that same year was 96.0% above the oee world-class standard (90% ) and that of the performance rate 129.3% also above 95% oee world-class standard (jain et al., 2013). also looking at table 4.2, comparing the actual volume of product produced and the target, the margin/difference between the actual and target for year three (2019) is 1,407,617 cases and that of year five (2021) is 665,297 cases hence the margin was higher positively in year three with over a million cases of the product and hence the year with the highest performance for filler benin plant even though year five recorded highest availability rate. however, through the year of the study from year one (2017) to year five(2021), the production targets were met and exceeded. this may be attributed to the type of plant maintenance strategy used and in this case, a combination of preventive and usage-based was used. the quality rate: table 4.5 shows that the quality rate was 99.9% all through the five years of study. table 4.5: quality rate of the filler machine year of study quality rate (%) year one (2017) 99.9 year two (2018) 99.9 year three(2019) 99.9 year four (2020) 99.9 year five (2021) 99.9 104.1% 108.3% 129.3% 66.2% 113.6% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% 140.0% year one year two year three year four year five p er fo rm a n ce ra te (% ) year of study mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 70 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset from table 4.5, it was seen that the quality rate was 99.9% throughout the five years of the study of the filler machine rgb benin plant. this will be attributed to the quarterly refit/overhaul done on the equipment yearround. this quarterly maintenance program is done on this machine. the refit is carried out four times every year on each plant, the filler is refurbished and the result is this excellent quality rate/quality product. however, this represents the usage-based maintenance recommended by the equipment manufacturer which is being followed by the nbc plants. apart from the routine preventive maintenance strategy, refit (usage-based) being combined gives a quality rate that met and exceeded the oee world-class standard of 99% (jain et al., 2013). with the right plant maintenance strategies 99.9% quality rate was obtained. 5.1 summary this was a retrospective study on the evaluation of maintenance in food and beverage manufacturing industries using nigerian bottling company (nbc) ltd, benin plant owerri plant, and bons industries limited, enugu. machines for the study were filler (krones), and packer/palletizer for nbc while blow mould, monobloc, and packer/caser for bons industries limited (these are bottling line equipment). it was found that the maintenance approaches used were preventive and usage-based in nbc while bons industries limited used preventive and condition-based based. availability rate, performance rate, and quality rates were high in both industries although nbc was better for both benin plant – south-south and owerri plant – south-east. this was because of the maintenance strategy used generally by nbc ltd, there is a quarterly refit on all production line equipment yearly. this means that there is a major maintenance/overhaul/refit schedule four times each year and a normal routine preventive maintenance is done routinely. however, all these maintenance activities are done in nbc with the embedded equipment manufacturer’s engineers/technicians team. also, the manufacturer’s (krones germany) maintenance recommendations were quarterly refit/overhaul and weekly preventive maintenance. 5.2 conclusions the approaches used for the maintenance of these machines in these manufacturing companies are preventive and usage-based in all the nbc plants used in this study and preventive and condition-based in bons industries limited. the availability rate, performance rate, and quality rate were high however performance rate was lower in the year 2020 in both companies due to the reasons given above (covid-19 pandemic). however, it was concluded after going through this study that the combination of preventive maintenance and usage-based maintenance strategies is the best and should be adopted/used by the food and beverage industries for optimal output and improved equipment performance. the cost of maintenance is better in nbc ltd than in bons industries ltd, the cost per case is also higher in bons industries than in nbc which is lower and considered favorable and friendly to the company’s profit margin. for nbc the cpc value is within two digits which is the standard/target for the company’s cpc. that of bons the value is up to three digits which is higher than the standard value for a manufacturing firm. hence, the combination of preventive and usage-based (overhauls) is considered better than the combination of preventive and condition-based used by bons industries ltd. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 71 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5.3 recommendations it is recommended that companies should carry out routine preventive maintenance and usage-based maintenance such as periodic machine overhauls since better result was obtained when compared to preventive and conditionbased based. for local/ indigenous companies like bons industries ltd, local manpower should be trained on machine maintenance, and in some cases of overhaul or refit, the owners/manufacturers of the machine should be involved as routinely done by the nbc plants. also, the equipment manufacturer’s maintenance recommendation should always be followed to achieve a highly favorable machine performance like that of nbc ltd. the equipment manufacturer’s guidelines/recommendation for maintenance are preventive and quarterly refit which is usage-based maintenance. for bons industries limited the equipment (china) manufacturer’s recommended routine preventive maintenance only. however, the company included condition-based maintenance to manage their equipment. references adeloye, l. (2010). harsh operating environment claims 834 nigerian manufacturing companies. the punch, 7 march, (online: http://www.jangola.com/index.php). alsyouf i (2004). cost effective maintenance for competitive advantage, phd. dissertation (terotechnology), sweden. växjö university press, acta wexionensia. alsyouf i (2007). the role of maintenance in improving companies' productivity and profitability. int. journal of production economics 105(1):70-78. al-najjar b and alsyouf i (2004). enhancing a company’s profitability and competitiveness using integrated vibration-based maintenance: a case study. european journal of operational research. 157: 643 – 657. al-najjar b, alsyouf i, salgado e, khoshaba, s and faagorg k (2001). the economic importance of maintenance planning when using vibration-based maintenance. växjö university, terotechnology. växjö university, sweden. al-najjar b (1997). condition-based maintenance: selection and improvement of a cost-effective vibration-based policy for rolling element bearings. doctoral thesis, lund university, sweden. alter, s. (2007). the work system method: connecting people, processes, and it for business results. work system press. bolaji b.o, adejuyigbe s.b (2012). evaluation of maintenance culture in manufacturing industries in akure metropolitan of nigeria. journal of information engineering and applications. 2(3): 37-45. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 72 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset didier n (2002). “manager les performances”. instep consulting editions, paris. dubrovsky, v. (2004). toward system principles: general system theory and the alternative approach. systems research and behavioral science, 21(2), 109-122. food and agriculture organization of the united nations (fao), (2018). food safety and quality. retrieved from http://www.fao.org/food-safety/en/ foon s.w and terziovski m (2014). the impact of operations and maintenance practices on power plant performance. journal of manufacturing technology management. igbokwe nc, godwin h.c (2021). maintenance performance evaluation and downtime analysis of manufacturing equipment in a food manufacturing company. journal of engineering research and reports. 20(11): 100107. jain a, bhatti r, singh h (2013). improvement of indian smes through tpm implementationan empirical study. in an international conference on advances in mechanical engineering.1-7. kirkpatrick, d. l. (2006). improving employee performance through appraisal and coaching (2nd ed.). new york. pp. 66–69. ludarig k (1968) performance measurement system design – a literature review and research agenda. int j of oper and prod manag 15(4): 80–116. maletič d, maletič m, al-najjar b, gomišček b (2014) "the role of maintenance in improving company's competitiveness and profitability: a case study in a textile company", journal of manufacturing technology management, vol. 25, no. 4, pp.441 456 martinelli, d. p. (2001). systems hierarchies and management. systems research and behavioral science, 18(1), 69-82. mifdal l, hajej z, dellagi s, rezg n (2013). an optimal production planning and maintenance policy for a multiple-product and single machine under failure rate dependency. ifac proceedings, volumes (ifacpapersonline). oba p. (2008). materials management in nigeria. business day, 04 march, p.23. ondiek go (2009). assessment of materials management in the kenyan manufacturing firms – exploratory survey of manufacturing firms based in nairobi. journal of social sciences, 22(8). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 73 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset oseghale, g.e (2014). impact of maintenance strategies on the performance of industrial facilities in selected industrial estates in lagos state, nigeria. american journal of engineering research (ajer) volume03, issue-08, pp-171-179. piotrowski j (2001). pro-active maintenance for pumps, archives, february 2001, pump-zone.com [report online]. available url: http://www.pump-zone.com. skyttner, l. (1996). general systems theory: ideas and applications. world scientific publishing co. steele, g. r. (2003). critical systems thinking and the methodologies of contemporary management. management decision, 41(8), 821-828. uforo a. e, usoro m.u and baridam d (2022) maintenance management and organizational performance in selected manufacturing firms, akwa ibom state. international journal of business and management review, vol.10, no.4, pp.37-59. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset spatial and temporal variations in properties of rainwater in ibi local government, area of taraba state, nigeria. abubakar idris abubakar enugu state university of science and technology, enugu doi: https://doi.org/10.5281/zenodo.11174484 abstract: location and season have a significant effect on rainwater properties. this study examined spatial and temporal variations in properties of rainwater in the ibi local government area of taraba state, nigeria, by identifying rainwater properties, spatial and temporal variations. the study was carried out between march and july 2023, using a purposive sampling technique. statistical data analysis of pearson correlation and chi-square test of mean values were used. the parameters analyzed were temperature, electrical conductivity, turbidity, ph, tds, tss, so4, no3, na, ca, cl, cd, mg, fe and pb. laboratory test methods used were astm and apha. the result showed that there were significant variations in rainwater properties in ibi local government area of taraba state. the rainwater variations could be attributed to higher anthropogenic and natural factors. out of 15 parameters tested, one (1) parameter was above who and nsdwq maximum permissible limits for drinking water quality. the parameter is turbidity. it had the mean values of 22.7ntu and 14.17ntu in urban and rural areas respectively. the maximum permissible limit by nsdwq and who is 5.0ntu. the elevated values in both urban and rural areas could be due to suspended and dissolved organic matters. turbidity was above all the standards in april and june, but within the standards in july due to rainfall intensity. dusty and poorly maintained roads could be attributed to high turbidity concentration in the study area. this study recommends that authorities should monitor and control the sources of atmospheric emissions through good road maintenance culture and proper waste disposal system in the study area. keywords: rainwater, variations, atmosphere, properties 1.1 introduction water is a unique resource whose quality and quantity vary over space and time. it is one of the most precious commodities needed by man. without it, life cannot survive and economic development will be retarded by its absence. water is the life-blood of the ecosystem. it forms the largest part of the most living things (origho, 2019). it is sourced from the earth’s surface as surface water, the crustal part of the earth surface as underground water, and the atmosphere as rainwater. rainfall has been of primary importance in most studies on climate science, with its variability exerting significant impact on the society. it is a major component of the hydrologic mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cycle and contribute to freshwater deposits on earth as well as provides good conditions for all types of ecosystems. it is also essential for hydroelectric power (hep) generation and irrigation for better crop yield (chidiebere, 2017). spatio-temporal methods in geography are significant because they allow for the analysis of the spatial and temporal patterns and trends of events. these methods are particularly useful in understanding the dynamic nature of geographic events, such as crime, agriculture or disease occurrences, by considering both time and space in the analysis. they enable the identification of spatial distribution changes at a finer scale, which is important for forecasting and minimizing disruptions in broadband service. additionally, spatio-temporal geo-statistics has emerged as a method to estimate and quantify environmental factors in a spatial domain, enhancing the precision of geographical subjects like precision agriculture. these methods contribute to a better understanding of the evolution of social and environmental phenomena within space (international water management institute, (iwmi, east africa, 2014). ademola, kehinde and ologunorisa, (2023), observed that there is more rainfall in nigeria between march and october, and less rainfall between november and february. rainfall amount in the niger delta is observed to be high due to its closeness to the atlantic ocean and presence of highlands that aids orographic processes. while abdullahi, wali and nwankwaola (2019), noted that proximity of niger delta to the atlantic ocean and topography contributed greatly to variation in rainfall characteristics in nigeria. with regards to spatial rainwater properties, pu et al, (2019), opined that chemical composition of rainwater varies from site to site and from region to region, indicating local influences and characteristics of atmospheric pollutants. therefore, mahato et al, (2016) submitted that rainwater composition reflects the quality of atmosphere during the occurrence of rainfall. in china, for instance, rainwater is an essential pathway to remove fine particulate matter and dissolved atmospheric pollutants such as nh3, so4, and nox (rui and guilin 2021). meanwhile, fine particles (pm2.5) are primary pollutants of substantial public concern in urban cities (wei et al., 2019). through wet precipitation, rainwater scavenges air pollutants from the air (niu et al., 2014; rao et al., 2016; wei et al., 2020). atedhor, aiyeki, and ayeni, (2019), stated that urbanized landscapes are known to have relatively high atmospheric pollutants due to high concentrations of anthropogenic activities. rainwater has its constituents including various substances that fall from the atmosphere as wet deposition during a rainfall event (tomasi, fuzzi, and lupi, 2017). simultaneously, growth in population and human activities in urban landscapes enhance pollutant release and particulate loading in the atmosphere (zhang, liu, he, pu, and yu, (2017). densely settled areas discharge substantial quantities of effluence into the atmosphere (baklanov, grimmond, carlson, and langendijk, 2017). thus, the transformation of rural domains into urban spaces significantly influences the local air quality (george, ziska, bunce, and quebedeaux, 2007). the area of study has low commercial activities, and lacks industrial presence, although it has a good network of roads, but poorly maintained. consequently, the roads are dusty and they link taraba state with plateau, nasarawa, and benue states. as a result of interstate link roads coupled with activities of boat engines and other human and natural activities, there is an increase in atmospheric pollution which impacts rainwater constituents. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the rainwater constituents depend on the intensity, frequency, and location of where it falls. this reason necessitated the need for this study. 1.2 statement of the problem the interference of some elements with rainwater in the atmosphere and the environment in which they fall alters the chemistry of the water. similarly, rainwater constituent is affected by rainwater intensity, particularly in the wet season. although rainwater is safe, the chemical composition at the point of collection is altered and is influenced by local environment and atmospheric conditions; hence, different places might have different elemental concentration levels. therefore, the study is aimed at determining spatiotemporal variations in rainwater chemistry in the study area for a better understanding of rainwater management. the impact of location and season on rainwater chemistry is one significant way of defining natural and anthropogenic contributions to environmental pollution. 1.3 aim and objective of the study the main objective of the study is to examine the effect spatial and temporal variations in properties of rainwater in ibi local government, area of taraba state, nigeria. the aim is achieved through the following objectives:  to identify causes of spatial and temporal variations in properties of rainwater in the study area?  to determine the factors responsible for spatial and temporal variations in properties of rainwater 2. review of related literature the state of the atmosphere over an urbanized area may differ significantly due to a relatively high and increasing load of atmospheric impurities (atedhor, ayeni and aiyeki, 2019). in examining variations of rainwater properties in wukari, local government area of taraba state, abubakar and ajadike (2023) observed that high chemical composition in rainwater from urban areas as compared with rural areas could be attributed to atmospheric chemical accumulation of pollutants such as gases and particulate matter. therefore, the study concluded that location is an important determinant of variability of rainwater properties. the chemical composition of rainwater can serve as a tracer for air pollution (zheng et al, 2020). abubakar and ogbu (2023), reported that south-east rainwater was more polluted than south-south in southern part of nigeria. the report concluded that it could be due to activities of industries and rainfall intensity that could have diluted the chemical composition of rainwater in south-south, nigeria. rainwater temporal analysis shows that, we have less rainfall between november and february (dry season) and the four study areas have bi-modal rainfall peaks. however, results from spatial analysis indicates that calabar had the highest rainfall amount followed by port harcourt, uyo and benin, this is due to the closeness of these locations to the atlantic ocean that contribute a lot of moisture in these locations (akinbobola, lawal and ologunorisa, 2023. the nigerian climate comprises of two seasons, the dry and the wet season with little dry season within the wet season (akinbobola et al, 2023). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset similarly in benin city, atedhor et al, (2019), examined the spatiotemporal variations in rainwater physicochemical properties. the result from three sampling areas shows that fe and nox mean values were higher in march than in july from all the sampling points. the study concluded that the efficiency and rate of washout scavenging of atmospheric pollutants increase with rainfall amount considering the fact that the month of july coincides with one of the rainfall peaks in the rainforest belt where benin city is located, while march, marks the on-set of wet seasons. aderonke et al, (2017) argues that temporal variation showed that all the chemical parameters had higher concentration values during dry season (october to march) than wet season, except nox and so4 ions. the study also shows that the major sources influencing the chemical parameters in rainwater includes remobilized dust from industrial activities, vehicular activities, agricultural activities and soil resuspension. methodology study area study area, ibi is one of the 16 local government areas (lga) that makes up taraba state. it lies within lat.8°01' and 8°35' north of the equator and long 9°10' and 9°98' east of greenwich meridian. figure 1: showing area of study source: taraba state ministry of land and survey, (2023) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to the west, it shares boundary with nasarawa state, to the east gassol lga, to the south, wukari town and to the north, plateau state. it has population of 84,054 in 2006, projected to 132,600 people by 2021 (npc, 2006). due to the richness of the minerals in the parent rock; its soils are generally well suited for rice, maize, guinea corn likewise arable farming and tree crops production. the lga covers an area of 2,672km² (bureau for land and survey, jalingo taraba state, 2012). the town ibi, was founded by yakubu bula, the first king who is a fulani from gombe. according to oral tradition, ibbi was originally spelled ibbe, meaning 'fig tree' in fulani language. figure 2: google map of the study area showing the sampling points this tree is very important to the fulanis because it has many uses as food, medicine, shelter for birds and abode of the spirits. the name became ibbi because of the impact with europeans who pronounce it as ibbi (ibi emirate council, 2006), now spelled as ibi. the notable economic activities of the inhabitants are fishing and farming. however, taraba and donga rivers flowed into the benue river within the lga figure (1). the mean annual rainfall is 1016-1270mm. the confluence in this lga pose sharp memory to the underground water, couple with high rainfall, yearly flooding is eminent adelalu, (2014b). the rural area consists of sarkin kudu and gindin waya, under ibi local government area. both are situated along trunk 'b' road that passes through wukari, gindin-waya and terminates in ibi due to river benue. however, the road continues after crossing the river benue to sarkin kudu through to lafiya in nasarawa state and part of benue and plateau states. by using google map, distance between ibi to gindin-waya is about11,900m, while it is about 12,800m from ibi to sarkin kudu. sampling and analysis mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the sampling technique employed was purposive. the sample containers were soaked with 10% hno3 for 24hours, well rinsed with water, distilled water and with sample before actual sampling took place. rainwater sampling locations were ibi central mosque, gindin-waya primary school and sarkin kudu, adjacent to ward chief's house. to ensure the rainwater samples had no contact with any object before getting into the bucket, an elevated platform of about 2m above the ground level (plastic drum) was used in an open space. samples were wrapped in a black cellophane bag, to prevent further oxidation and placed in a cooler box packed with icedchips. samples were transported to laboratory for analyses. the following parameters were tested: temperature, ph, electrical conductivity, colour, turbidity, nox, tss, tds, ca, mg, so4, fe, pb, cu and zn. american society for testing and materials (astm) and american public health association (apha) test methods were used. data collection multi meter pcs tester 35 was used for ph, temperature, ec and tds, concentration values were recorded in 0c, µs/cm and mg/l respectively. ph has no unit of measurement. turbidity was tested using hi 93709 hanna turbidity meter and reading was taken in ntu. gravimetric method was used for tss by using filter paper (whatman) of pore size 0.45mµ with aid of suction pump, reading was taken mg/l. for so4 concentration, spectrophotometer, spectrum lab s23a was used. a complex titrimetric method was used for nox. acidic potassium bromates and sodium nitrite with starch as indicator was titrated until the color in starch iodine paper turned blue, indicating endpoint. for metals; fe, zn, cu, cd, pb, mg and ca, faas (aa-6300 shimadzu) was used. a light beam from a hollow cathode lamp of the same element as the target metal is radiated through the flame, and the amount of absorbed light is measured by the detector. concentration was displayed on the monitor in mg/l. result table 1: spatial properties of rainwater in the study area parameter urban rural range nsdwq fepa who ph 8.08 7.59 7.59 8.25 (0.66) 6.5-8.5 6-9 6.5-8.5 temp (0c) 29.07 30.63 28.0-31.5 (3.50) ambient 20-35 ambient cl (mg/l) 16.54 8.16 7.01 31.95 (24.94) 150.0 tds (mg/l) 61.97 23.07 5.4 – 174 (168.6) 500 2000 500 ec (µs/cm) 40.93 22.6 6.3 107.4 (101.1) 1000 1500 1000 turb (ntu) 22.97 14.17 4.9 61.9 (57.0) 5.0 5.0 5.0 tss (mg/l) 18.67 17.53 10.0 30.0 (20.0) 500 500 500 so4 (mg/l) 1.7 0.15 0.08 4.91 (4.83) 100.0 20.0 20.0 no3 (mg/l) 6.02 5.52 2.42 8.73 (6.31) 50.0 20.0 50.0 ca (mg/l) 4.11 3.14 3.1 4.62 (1.52) 75.0 75.0 mg (mg/l) 2.15 1.71 2.06 2.19 (0.13) 20.0 20.0 na (mg/l) 0.09 0.13 0.08 0.10 (0.02) 200 150.0 pb (mg/l) 0.01 0.01 0.01 0.01 (0.00) 0.01 0.01 0.01 cd (mg/l) <0.001 <0.001 0.001 0.003 (0.002) 0.003 0.05 0.003 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fe (mg/l) 0.21 0.12 0.05 0.51 (0.46) 0.30 0.05 0.30 source: fieldwork (2023) figure 2 shows changes in rainwater properties with respect to location. ph, cl, tds, ec, turb, tss, so4, mg, ca, mg, and fe had high values in urban than in rural areas. however, temperature and na were high in rural than in urban areas. pb and cd had the same values in both areas figure 2: spatial variation in rainwater properties source: field work (2023). 0 10 20 30 40 50 60 70 co nc en tr at io n urban rural mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: temporal variation in rainwater properties source: field work (2023) figure 3 shows that, rainwater properties were affected by rainwater frequency and intensity which increases from march through to june as reported by aderonke et al, (2017). the figure also indicates decrease in rainfall intensity in the month of july, which proportionally influences rainwater properties. for instance, from the 15 properties tested, 67% had high values in april, 20% (ph, nox and ca) in june and 6.5% (pb and cd values of <0.001) in july. figure 4: rainfall and temperature variations; source; nimet (2023) 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 ra in fa ll (m m) april june july 0 20 40 60 80 100 120 140 160 jan feb mar apr may jun jul rainfall (mm) temperature (0c) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4 shows that there was no rainfall in january and february in the study area. however, 6.7mm of rainfall was recorded in march. the rainfall progressed through april, may and june (142.3mm). in july, there was reduction in rainfall amount to 92.1mm. the temperature values used was average of the highest temperature in the study area, this is because, nimet data received is highest and lowest temperatures. temperature values rose with rainfall amount. in january, february and march, the temperatures recorded were 29.5, 31.0 and 32.00c respectively. it increased to 31.50c in may, while june and july recorded 30.2 and 28.90c respectively. data analysis ph – the rainwater samples were alkaline, with mean value of ph range as 7.59 to 8.25 (0.66). the mean value of ph for urban and rural areas were 8.08 and 7.60 respectively. the ph of typical rainwater is acidic; the reason is that water reacts to a slight extent with atmospheric carbon dioxide and nitrogen dioxide to produce carbonic and nitric acids. this phenomenon occurs mainly due to dependence on fossil fuels as energy source, which have resulted in acid rain formation (zhao et al, 2019). the result suggests that the study area has low industrial and commercial activities; acidic gases were minor in concentration and the effect of particulate matter of alkaline nature like dust particles were dominant as found by abulude et al, (2018). the mean ph of 8.08 and 7.60 were within maximum permissible (mpl) of who, nsdwq and fepa. temporarily, the ph values were 7.47, 7.87 and 7.97 in march, june and july respectively. the ph remained constantly alkaline, indicating lack of strong acidic ions to neutralize the rainwater. acidic components in rainwater are from so4 and nox ions; products of fossil fuel combustion. this opinion agrees with findings of francis et al, (2018), who stated that the alkaline result obtained in samples, could be due to lack of industrial activities, lack of high traffic and low commercial activities. this is supported by egwuogu, okhake, emenike and abayomi (2016). turbidity – turbidity of water refers to how clear the water is and it is caused by the presence of particulate matter such as clay, silt, plankton and colloidal particles. heavy rainfall, strong winds and convection currents can increase the turbidity of rainwater to a high degree (waziri, akinniyi and ogbodo, (2012). these particulates cause light to be scattered and absorbed rather than transmitted in straight lines through the sample (fsai, 2015). the range of turbidity values were between 4.9 and 61.9 (57.0) ntu. the mean values obtained were 22.97ntu and 14.17ntu for urban and rural areas respectively. the urban area had higher turbidity than the rural area. these were equally higher when compared with 4.05ntu recorded by efe and mogborukor, (2011) in niger delta on rainwater quality within the same period. however, the values were lower than what was reported by ebong et al, (2016), from south-south region of nigeria. the higher value in urban area is an indication of higher human activities than in the rural area. human activities such as bush burning and fish smoking, and could also be attributed to exhaust from vehicle emission. arif et al, (2021), who studied rainwater chemical properties in bangladesh, concluded that high turbidity reflects the presence of particulate matters in the atmosphere and that, it was influenced by anthropogenic activities such as transportation, commerce and agriculture. adeyeye et al (2019), reported the turbidity of ikole in ekiti state as 0.47ntu, indicating low human activities. unlike in niger delta, where industrial and commercial activities were high, the turbidity recorded by azuonwu, et al, (2017) was 9.0ntu. the major effect of turbidity is aesthetic and high levels of turbidity for a short period of time may mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset not be significant than a lower persistent level. in april, june and july, the turbidity were 28.73, 5.47 and 4.32ntu respectively. rainwater was more turbid april; this could be due to lower rainfall amount and bush burning associated with planting season (mojeed and tanimola 2018). it could be effect of early rainfall which carries polluted air as a result of anthropogenic activities (zheng et al, 2017). the average temperature of 29.70c for urban area and 30.630c for rural area were recorded. the temperature was measured in-situ. the temperature range was 28.0.0-31.5 (3.50)0c. it affects some of the important physical and chemical properties of water; thermal capacity, density and weight. the higher the temperatures’, the higher the solubility of solutes. the temperature range was in line with adetunji, adebayo and tanimola, (2017), when studying rainwater quality around a cement producing firm in ewekoro, south-west nigeria. the result indicated that the ambient temperature was 26.30c. this also agrees with who′s mpl of 20-300c as reported by azuonwu et al, (2017). in bichi lga of kano state, emmanuel (2019) recorded the average temperature of 25.030c. the temperature recorded in april, june and july were 30.97, 28.10 and 27.930c respectively. it reduces with increase in rainfall. global increase in temperature is as a result of increase in greenhouse gases (ghgs), due to human activities such as industrial pollution, destruction of nature, combustion of fuel, gas flaring, used chemicals (cabasch, 2013). so4 – the result showed that the range of so4 was between 0.08 and 4.91(4.83) mg/l. the recorded mean values were 1.70mg/l for urban and 0.15mg/l for rural. emissions of so4 are attributed to sources of rainwater acidity. however, low value in rural area could imply that there were minimal anthropogenic and low sources of emissions of oxides of so4, carbonates and nox and ozone to some extents are the primary causes of acid rain. this result asserts that the findings of zhong et al, (2017) who found that so4 and nox are from anthropogenic activities, while fu et al, (2017) suggests that so4, nox and ca are primarily derived from urban construction, agricultural activities and vehicle emissions. the recorded mean values were within nsdwq, fepa and who mpl of 100mg/l and 250mg/l respectively. urban area had high commercial, traffic and particulate matter emission sources than the rural areas. in an industrial area of shanghai in china, the so4 recorded was 200mg/l and in some selected communities of niger delta, it was 2.10mg/l, according to azuonwu et al, (2017). april, june and july had mean values for so4 as 1.77, 0.11 and 0.12mg/l respectively. high so4 values in rainwater were observed due to low rainfall intensity in april. this is supported by aderonke et al, (2021) and abubakar and ajadike (2023). the nitrates range for the study area was between 2.42 and 8.73 (6.31) mg/l. the data showed mean values of 6.02mg/l for urban and 5.52mg/l for rural area, which were within the nsdwq and who mpl of 50.0mg/l. the high value in urban area could be due to high commercial, road construction and transportations activities. settled areas discharge higher pollutants to the atmosphere (zhong et al, 2017). similarly, zhao et al, (2019), is of the opinion that emission of so4 and nox affect rainwater properties and imo et al, (2021), believes that chemical composition of rainwater varies from site to site and region to region depending on the influence sources point and anthropogenic activities. this position is supported by daniel et al, (2020), who stated that the nitrate concentration level in some parts of port-harcourt, and that they were in decreasing order based on locations from mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset chokocho, ogale, rumuodamaya and diobu. the study concluded that it could be attributed to fertilizer, agroallied industries based in the area. this opinion also corroborates with zhao et al, (2019), who said that, dependence on fossil fuel has resulted in frequent rainwater physico-chemical properties change or alteration. since, rainwater quality is influenced by the local activities (cobbina et al, 2013), the result obtained shows that april, june and july values were 2.07, 9.18 and 5.81mg/l respectively. april had the highest nox concentration due to less quantity of rainfall in the month that could have cleaned the atmosphere (akinbobola et al, 2023). higher concentration of nox experienced in june was due to less intensity of rainfall within the month as shown (fig 4). ecthe ec value of rainwater is directly related to the total amount of soluble ions. thus, lower ec values indicates that the air quality is improved or rainwater has a higher dilution effect (zhang et al, 2017). the range of ec in the study area was between 6.30 and 107.40 (101.10) µs/cm. ec of urban area mean value was 40.93µs/cm, while the mean values for rural areas was 22.60µs/cm. these figures were lower than 1000µs/cm, the mpl by nsdwq, fepa and who standards. high mean value of ec in rural area could mean high human activities (zhang et al, 2017), particularly farming activities in the rural area. another factor that could have contributed to high ec in the rural area could be long range particles and dusts transport as suggested by li et al, (2016). ayeki et al, (2017), reported that the higher conductivity in rural area could be attributed to sources of particulate matter that interacts with rain to form ions. adetunji et al, (2017), reported the ec of 6.9µs/cm in ikole -ekiti state respectively, the town is a commercial centre with high population and industries. the reported area had values lower that the study areas, this could be attributed to rain intensity dilution effect. it could also be as a result of wind action that could have transported dissolved chemical substances in the atmosphere. this agrees with egwuogu, (2016), when he studied rainwater quality in different communities of obio-akpor, river state. these figures were all higher than the study area, which further validates that the study areas lack industrial presence. ec values in april, june and july were 71.34, 10.13 and 4.67µs/cm respectively. the temporal data indicates that april had the highest ec as compared to june and july. since rainfall started in march and intensity progresses with season as shown in fig 4. low value in july could be attributed to rainwater dilution effect (abubakar and ogbu, 2023). tds – it consists of inorganic salts and small amounts of organic matter present in dissolved form in rainwater. the value of tds depends upon atmospheric composition of that area. the data showed that the range of tds in the study area was between 5.40 to 174.0 (168.6) mg/l. the mean value for tds in urban area was 61.97mg/l, while it was 23.07mg/l for rural area. the figures were within the nsdwq, fepa and who mpl of 600/2000/500mg/l respectively. the reason for elevated tds in urban area could be reflection of high anthropogenic activities, such as presence of local government offices, banks, schools’ markets, boat engines and motor parks. this assumption agrees with belonwu et al, (2016) on research conducted on three sites in core benin city. the investigation reported that there was reduction in water pollution concentration from the core to periphery which was attributed to lower anthropogenic activities in the area. the research concluded that, although, densely populated area had value lower than non-populated areas, this could be attributed to wind mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset action. this assertion supports ayeki et al, (2019) argument, on ability of wind trajectory action to carry suspended particles far away from the source. this is also in line with report of vincent et al, (2016), on impacts of emissions from crude oil tanks and gas flaring sites on bonny island. the research concluded that, the turbulence generated from the flare instigated the initial dispersion of the pollutants which were transported to the residential areas found downwind of the industrial area in the bonny island. low values in july, shows that the atmosphere was cleaner due to intensive rainfall. for the monthly variation of rainwater properties in the study area, the april, june and july had tds value as 95.73, 7.07 and 5.30mg/l respectively. the high value in april is an indication of high dissolved chemical components of rainwater in the atmosphere. however, the values decrease with increase in rainfall quantity as reflected in june and july results. this assumption is supported by gowin et al, 2019 and aderonke et al, 2017. tss – it can cause water to be cloudy, and reduces water transparency. tss is a measure of turbidity or cloudiness of water. the range of tss in the study area was between 10.0 and 30.0 (20.0) mg/l. urban and rural areas had tss mean value of 18.67 and 17.53mg/l respectively. low tss value in rural areas could be an indication of low sources of spm and other human activities. this opinion, also agrees with the work of ebong et al, (2016) and adeyeye et al, (2019), that particulate matters concentration in atmosphere influences the quality of rainwater harvested. this opinion is similar to that of emerole, (2015), who emphasized the impacts of population density on quality of rainwater in orji community in imo state. tss obtained results were within nsdwq and who mpl of 500mg/l. onah, obasi and ossai (2019), studied physico-chemical quality of rainwater in five selected sites of enugu; agbani, imt, coal city, abakpa and emene. the mean tss value in these sites was 305.6mg/l. elevated values are indication of higher population, presence of industries and other anthropogenic activities. data for temporal variation of rainwater properties shows that the tss mean result for april, june and july were 28.24, 10.67 and 14.82mg/l (fig. 3) april had the highest tss concentration, followed by june and then july. this shows the effect of rain intensity on the rainwater properties. this assumption is supported by ebong et al, (2016). mg – the range of mg in the study area was between 2.06 and 2.19 (0.13) mg/l, while the data shows that urban area had the mg ions of 2.15mg/l, rural had 1.71mg/l. the figures obtained were within nsdwq and who mpl of 20.0 and 50.0mg/l respectively. the urban area had elevated result due to human activities in the area (zeng et al, 2019 and imo et al, 2020). mg and other alkali (e.g. ca) are responsible for water hardness. ca and mg ions are soluble in water but they constitute hardness. ikole town, where a cement company is sited in south-west nigeria, had mean mg value of 2.40mg/l. the value was slightly higher than the study area. this could be attributed to the presence of industrial and other commercial activities around ikole town. the assertion also agrees with kabir and madugu (2010), that physico-chemical constituents of rainwater often reflect environmental impact of land use activities in an area. although, the effect of atmospheric pollutants can be transboundary, studies here indicated that concentration of certain chemicals can be more in certain vulnerable environment than the less vulnerable region. garcia-martinez et al, (2020), who recently worked on chemical composition of rainwater in mexico, reported a comparative data on mg ion concentration in coastal, mountainous, dusty and urban areas of mexico as 26.0, 7.73, 24.1 and 9.90mg/l respectively. coastal area having mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the highest mg ion value, followed by dusty areas. temporarily, april, june and july had mean mg values of 2.02, 1.87 and 1.68mg/l respectively. low values in june and july showed the effect of rainfall intensity on mg ion concentration. rainfall frequency and intensity have dilution effect on physical and chemical constituents of rainwater in the study area as supported by vincent et al, (2020) and abubakar and ogbu, (2023). iron – fe concentration range in the study area was between 0.05 and 0.51(0.46) mg/l. fe values of 0.21mg/l and 0.12mg/l were recorded for urban and rural areas respectively. they are within who, fepa and nsdwq mpl of 0.30mg/l. the high value of fe in urban area could be attributed to higher population, commercial activities and transportation sources in the area. this view agrees with xu et al, (2020), who stated that industrialisation, urbanisation and transportation are key sources of rainwater pollution in the atmosphere. other sources of fe concentration in urban rainwater could be through crustal source, quarrying and construction activities, or through fossil fuel combustion. in some locations in akwa-ibom state, ebong et al, (2016), had the concentration of fe in eket and ibino-ibom as 0.59mg/l and 0.22mg/l respectively. eket town, an oil producing area had fe concentration higher than in ibino-ibom, a non-oil producing area. similarly, arif et al (2021), reported fe range from 0.00 to 440mg/l, in jordan, india and japan with mean iron value of 4.30, 69.2 and 7.50mg/l respectively. india. from monthly variation, fe concentration had the highest value in april. there was increase in concentration of fe from april, june and july as 0.27, 0.07 and 0.07mg/l respectively. this explains the effect intensity of rainwater (dilution) on properties of rainwater in the study area. this argument is supported by aiyeki et al, (2019). pb – the range in the study area was between 0.01 and 0.01(0.0) mg/l. urban and rural areas had the mean values of 0.01mg/l, the values were within nsdwq and who mpl of 0.01mg/l. although pb concentration is within nsdwq and who mpl, it is on the threshold limit (0.01mg/l), and this calls for concern from well-meaning authority. the study area had no industrial presence and most of the people living in the area are predominantly farmers and fishermen, presence of pb in rainwater is an indication of atmospheric pollution with combustible materials from petroleum products and crustal activities (subodh, 2021). this assumption is supported by subodh, (2021). therefore, the pb in the study area could be due to wind trajectory action that might have transported pb from other locations (zheng et al, 2017). in evaluating spatial rainwater quality in six selected areas of akwaibom state, between march and november, 2008-2010, ubuoh, et al, (2012), found out that the range in pb concentration was 0.01-0.014mg/l. april, june and july had mean pb value of 0.01mg/l in the three months. the same value throughout the study period is an indication of recalcitrant presence; rainfall intensity and frequency had no effect on its concentration. this calls for concern. cadmium – it is extracted during production of metals such as cu, pb and zn. it can be found in certain foods and also emitted by burning fossils fuels like oils, coal and during smoking cigarette. cd range was between 0.001 and 0.003 (0.002) mg/l. urban and rural areas had mean value of 0.001mg/l each. the obtained shows that the values were within nsdwq, fepa and who mpl of 0.003mg/l. this could be attributed to low human activities and low population density in the study area. this assertion is supported by researchers such as, ubuoh, (2012; 2016), arif et al, (2020) and zu et al, (2020). ona et al, (2019), reported the mean concentration of cd in mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset enugu as <0.001mg/l. similarly, arif et al, (2019), reported comparative concentration of cd in jordan, mexico and india as 52.0, 80.5mg/l and <0.001mg/l in india. therefore, data suggests that, the study area lack industrial activities and other human activities that could have generated dusts and particulate matter in the atmosphere. the data from monthly variation of physical and chemical properties of rainwater in the study shows that, april, june and july had cd concentration of 0.001mg/l. ca – the range was between 3.10 and 4.62 (1.52) mg/l in the study area. urban area had mean value of 4.11mg/l, while the rural area had 3.14mg/l. the value of ca in urban area was higher than the value from rural area. the obtained values shows that the urban and rural areas had value within nsdwq and who mpl of 75.0 and 100mg/l respectively. this could be attributed to low human activities and low population density in the study area that could have generated dusts and other suspended particles to the atmosphere. ca is a ph stabiliser; it has a neutralising effect on rainwater. ca and na are mostly from marine contribution that have long-range transportation of sea salts and limestone mining from quarries (patrick and el shalom, 2020). this assertion is supported by whiley, edwards and ross (2018), that the characteristics of rainwater depends on the atmospheric particulate, gaseous constituents produced locally or transported from distant sources by natural or anthropogenic sources. this shows the effect of atmospheric chemical component during the dry season, usually higher due to dusts and particulate matter present. (aderonke 2017). similarly, the data from monthly variation of physical and chemical properties of rainwater showed that, april, june and july had ca concentration of 3.94, 4.05 and 2.39mg/l respectively. april and june values were within the same range. this could be due to wind transport effect as supported by zheng et al, (2017). cl – the ion is naturally occurring in most natural waters and is most often found as a component of salt (nacl) or in some cases in combination with ca and mg. the source could be from agro-allied fertilizer and industrial activities which are from dissolution of aerosol in the atmospheric interaction with rainwater (patrick and el shalom, 2020). cl ion range was between 7.01 and 31.95 (24.94) mg/l. urban and rural areas had mean value of 16.54 and 8.16mg/l respectively. the higher cl value in urban could be traced to higher human and crustal activities in the area. although, the cl values for both urban and rural were within the nsdwq and who mpl of 150mg/l, the cl ions could have spread to the atmosphere from natural or anthropogenic sources in the area as asserted by martins and nagorotto, (2019). chemical composition of rainwater clearly reflects the degree of air pollution in urban, rural and industrial biomes. to corroborate this assertion, rao et al (2016), and mahato et al, (2016), opined that, owing to the effect of local sources, the chemical composition of rainwater varies with geographical location. the data from monthly variation of physico-chemical properties of rainwater in the study area shows that, april, june and july had cl ion concentration of 17.17, 9.12 and 6.56mg/l respectively. april had highest na ion values when compared to june and july. it could be due to the effect of low rainfall as april marks the beginning of rainy season, as suggested by abubakar and ogbu, (2023), and ayeki et al, (2019) or could be due to high agricultural activities with intensity of rainfall in june on physico-chemical properties of rainwater in the study area as opined by zhang et al, (2017). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset na –it is commonly taken as the best reference element to marine source of atmospheric composition (cobbina et al, 2013). na range was between 0.08 and 0.10 (0.02) mg/l in the study area. urban area had mean na value of 0.09mg/l, while the rural area had 0.13mg/l. the na ion from rural area had mean value higher than the value from urban area. the higher na value in rural area could be traced to higher human or natural activities such as farming, wind action, nearness to geological formation with na. other sources could be transportation and the effect of particulate matter like dusts particles in the area as argued by abulude et al, (2018). the na values for both urban and rural were within the nsdwq and who mpl of 200mg/l, godwin et al, (2019), reported mean value of na in benin city as 1.83mg/l. nwineewii and egwuatu (2019), also reported the mean value of na in industrial area of port-harcourt as 33.49mg/l. temporarily, in april which marks the onset of wet season in the study area had na concentration as 0.17mg/l. june and july had 0.12 and 0.70mg/l respectively. the data suggests the effect of rainfall intensity on rainwater chemical composition (aderonke et al, 2017; godwin et al, 2019 and abubakar and ogbu, 2023) and low rainfall in july, shows that the atmosphere was cleaner. summary the 15 rainwater properties tested were within who, nsdwq and fepa mpl. turbidity was the only parameter above the three standards for drinking water and for environmental pollution. turbidity mean value were 22.7 and 14.17ntu for urban and rural area respectively. the elevated values in both areas could be due to high tss and tds in the atmosphere particularly in april which marks the period of rainfall onset. these particles and aerosols were generated by human and natural sources. this assumption supports the opinion of aiyeki et al, (2019), adeyeye et al, (2019), that particulate matters concentration in atmosphere influences the quality of rainwater harvested. however, the data from table 1, showed that 73% of the parameters (ph, turbidity, cl, tds, tss, ec, so4, no3, ca, mg and na) were higher in urban area than rural area, while 7% were high in rural (temperature) than in urban area. high anthropogenic activities such as transportation, road construction, fertilizer application, bush burning, fish smoking and power generation from power plants could be responsible (keresztezi et al, 2019). however, 20% of the physical and chemical parameters (pb, cd and fe) have the same values in both areas. this could be attributed to crustal activities (ebong et al, 2016 and mahato et al, 2016), as there is bridge construction that links taraba state with plateau, nasarawa and benue states within the study area. uban area (ibi town), experiences higher human activities such as transportation, farming activities, population density (due to location of lghq offices), presence of large markets, motor parks, banks, general hospital and schools. these factors contributed to emission of elevated quantity of pollutants, thereby contributing to the atmospheric chemical composition of urban areas. rural environment lacks industrial activities, production of gases such as carbon monoxide, nitrogen oxides, and sulphur dioxides could barely be significant to affect the quality of rainwater. this assumption is supported by researchers. for instance, presence of dissolved ions in rainwater (abbasi et al, 2017), farming activities (abulude and abdulkadir, 2018, agnes et al, (2020) and mojeed and tanimola, (2018), influence of dust particles in the atmosphere (abbasi et al, 2017, and abiodu and olabode, 2020), wind trajectory air mass movement (panam et al, 2017), and bush burning associated with planting season (mojeed and tanimola 2018 and aderonke 2017). temporarily, the ph values were alkaline mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset during the months of april, june and july. this could be an indication of low anthropogenic activities. natural rainwater is normally considered to be weakly acidic with a ph value of 5.6 (niu et al, 2014), when the atmosphere is free from pollution. this could also suggest that the influence of anthropogenic sources due to acidic gas was minor and the effect of particulate matter of alkaline nature-like dust particles was dominant (abulude et al, 2020). turbidity was above all the standards in april and june (28.73 and 5.47ntu), while july was 3.89ntu. from table 1, 60% of the parameters; turbidity, ph, temperature, tds, ec, mg, cl, na and fe show decreasing order in mean values. this could be attributed to low mean rainfall in april through to july; an effect of early rainfall which carries polluted air as a result of human and natural sources, (zheng et al, 2017 and ubuoh, 2012) as shown in figures 3 and 4. 13% of the parameters (cd and pb) showed the same values of rainwater properties within the sampling period, while 27% (ca, nox, so4 and tss) were not linear with respect to rainfall in mean values. this could mean that the amount released into the atmosphere is insignificant whether during rainfall onset or at its peak. recommendation based on the result obtained and data analysis carried out, i recommend the following; turbidity in rainwater is a product of suspended and dissolved particles in the atmosphere. dusts generation are caused by bad road condition and the high traffic in the study area. therefore, there is need for urgent road rehabilitation, this will reduce dusts that could have increased dissolved and suspended particulate matter in rainwater. in addition, it will further reduce the risks of bronchitis and related health challenges. domestically, turbidity can be removed by using moringa seed flocculation method. lead value at thresh hold level of 0.01mg/l is of great concern. relevant authorities should monitor it closely for proper management. conclusion the rainwater tested was alkaline, acidic component were not strong enough to neutralize the rainwater. ibi lga rainwater meet nsdwq, who and fepa standards for drinking quality and environmental pollution, except for turbidity. it is the quantity of suspended solids in water, affecting its aesthetic. spatially, the study shows that urban area experienced high values of physical and chemical properties, which could be attributed to human activities such as population, farming, poorly maintained roads that generates dusts, vehicular and engine boat transportation. this could have contributed to emission of gases, particulate matter and aerosols into the atmosphere; they dissolve in rain and fall to the earth surface as rainfall. temporarily, april has high value of rainwater physical and chemical properties as compared to june and july. the reason could be that, onset of rainfall, usually carries polluted air, whose particulate air loading is high due to the season (dry due to harmattan dusts), and human activities. the t-test analysis was carried out using spss version 23, the p value was 0.81, which suggests that there was no significant relationship between the variables. water quality varies with increase in rainfall. the wet season from study area has shown two distinct seasons with little dry season within the wet season. rainwater gets its chemistry based on the nature of atmospheric air composition which depends on location and season. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references abdullahi, m., wali, e., nwankwoala, h.o., stephen, h., (2019). application of remote sensing and gis for the study of rainfall distribution in nigeria from 20002019; american-eurasian journal of scientific research, 14 (3): 59-63. abubakar i a and ajadike, j c (2023) variations in physico-chemical properties of rainwater in rural and urban areas of wukari local government area, taraba state, nigeria; international journal of engineering and engineering sciences, 6(2), 30-39. abubakar i a and ogbu so (2023) review of spatial variations in physico-chemical properties of rainwater in south-east and south-south, nigeria; european journal of engineering and environmental sciences, 7(3), 12-20. aderonke, a. okoyal, bamikole, w. osungbemiro1, and temi, e. o. (2017) spatial and temporal variations of rainwater chemistry in ile-ife and its environment, osun state, nigeria: journal of sustainable development, 10, (2)3-10, akinbobola a, lawal, ka and ologunorisa t., (2023) spatiotemporal variability of rainfall as an evidence of changing climate over the nigerian niger delta; ghana journal of geography, 15(2), 212-238. arif, h. and asiful, h. (2020): comparative study of rainwater quality at cuet campus area, harvested from rooftop, and open space; 5th international conference on civil engineering for sustainable development (iccesd), khulna, bangladesh. atedhor go, ayeni ao and aiyeki ja (2019): spatio-temporal variation of the physico-chemical properties of rainwater in benin city; nigerian journal of cameroon academy of sciences, 14(3), 205-218 ayeki, j. a. asikhia, m. and ojeh, v. n. (2018): seasonal and spatial variation in physicochemical and biological quality of rainwater in benin city, edo: global journal of human-social science, 18 (5),1 babalola, o.s. and akinsanola, a.a. (2016) change detection in land surface temperature and land use land over lagos metropolis, nigeria; journal of remote sensing and g.i.s, 5: 171. baklanov, a., grimmond, c.s.b., carlson, d., terblanche, d., tang, x., bouchet, v., lee, b., langendijk, g., kolli, r.k. and hovsepyan, a. (2017) from urban meteorology, climate and environment research to integrated city services. urban climate; journal of climatology. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset eludoyin, a.o., ijisesan, o.s., (2020). water quality and influence of interpolation procedure on visualization of selected parameters in a headwater stream, in ayepe olode, southwestern nigeria; south african journal of geology. 9 (1), 44–60. ganyaglo, s.y., osae, s., akiti, t., et al., (2017). application of geochemical and stable isotopic tracers to investigate groundwater salinity in the ochi-narkwa basin, ghana; hydrology of science journal. 62 (8), 1301–1316. george, k., ziska, l.h., bunce, j.a. and quebedeaux, b. (2007) elevated atmospheric carbon dioxide godwin, o. a. amidu, o. a. and judith, a. a. (2019): spatio-temporal variations of the physico-chemical properties of rainwater in benin city; journal of the cameroon academy of science, l14, (3) harvey, j., gooseff, m., (2015) river corridor science: hydrologic exchange and ecological consequences from bedforms to basins; water resource. 51 (9), 6893–6922. international water management institute east africa, 2014 (http://eastafrica.iwmi.cgiar.org/. retrieved 10 feb 2024. kaihao lg, guilling w, jinxn z and shuo wsx (2021) american meteorological society, 1(12), 3159-3169 shuaibu vo, weli ve, (2017) relationship between pm2.5 and climate variability in niger delta, nigeria; american journal of environmental protection, 5(1), 20-24 sterte, e.j., lidman, f., balbarini, n., et al., (202) hydrological control of water quality–modelling base cation weathering and dynamics across heterogeneous boreal catchments; science of total environment; 799, 149101. thornton, p. k., 2014. rainfall and rainfall variability. in: sebastian k, ed. atlas of african agriculture research and development: revealing agriculture's place in africa. washington, d.c.: international food policy research institute (ifpri), 7:38-39. tomasi, c., lupi, a., 2017. coagulation, condensation, dry and wet deposition, and cloud droplet formation in the atmospheric aerosol life cycle: life cycles and effects on air quality and climate. xu, z.f, wu, y, liu, w.j, et al., (2015). chemical composition of rainwater and the acid neutralizing effect at beijing and chizhou city; china atmospheric resource. 164, 278–285. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset origho t, (2019) comparative analysis of the quality of rainwater harvesting from rural and urban communities in ughelli north lga, delta state, nigeria; international journal of environmental studies and safety research 4(4), 1-8 ventura a, simoes ec, almeida as and martins r, (2021) deposition of aerosols onto upper ocean and their impacts on marine biota; atmosphere, 12, 684, 1-14 who (2010) standard for drinking water quality; geneva, 3(1): 205-220 xia, y. zhang, l. xiong, s. he, l and wang, z. yu (2017) opportunities and challenges of the sponge city construction related to urban water issues in china; journal of science china earth sciences., 60 (4), 652-658, zhang, g., liu, d., he, x., yu, d., pu, m., (2017) acid rain in jiangsu province, eastern china: temporal and spatial variations features and analysis; atmospheric pollution resource, (6), 1031-1043. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the role of multimedia innovation in advancing ice and snow sports tourism qu, meng-yao physical education and research department, heilongjiang bayi agricultural university, daqing 163319, china abstract: the burgeoning interest in ice and snow sports in china has drawn the attention of both state authorities and relevant management departments. this newfound focus has led to the formulation of rules and regulations, along with the promulgation of documents that lay the foundation for the expansion of ice and snow leisure sports. notably, china's approach to ice and snow sports places a strong emphasis on sports and leisure activities, necessitating a synergy between the development of ice and snow leisure sports and the broader national ice and snow sports agenda. this paper explores the evolving landscape of ice and snow leisure sports in china, aiming to address the growing demand for such activities. as ice and snow sports continue to gain popularity, the public's appetite for ice and snow leisure experiences is steadily on the rise. ice and snow leisure sports tourism, rooted in china's abundant ice and snow resources, profound cultural heritage, and diverse range of ice and snow sporting activities, has emerged as a significant niche within the broader landscape of winter sports. this paper underscores the pivotal role of multimedia technology and the integration of the sports and tourism industries in facilitating the growth of china's ice and snow leisure sports sector. these advancements hold the promise of unlocking new opportunities and creating an expansive developmental horizon for ice and snow sports tourism in china. keywords: ice and snow leisure sports, sports tourism, multimedia technology, winter sports development, cultural heritage integration. 1. introduction in recent years, the state and relevant management departments have paid attention to the formulation of rules and regulations related to ice and snow sports, and the promulgation of relevant documents has provided a broader development platform for the development of ice and snow leisure sports in china. china's ice and snow sports take sports and leisure activities as the main focus, so the development of ice and snow leisure sports should also meet the needs of the development of national ice and snow sports. on the basis of the wide range of ice and snow sports, people's demand for ice and snow leisure is also gradually increasing. ice and snow leisure sports tourism activities are based on rich ice and snow resources, deeper cultural heritage and more diversified ice and snow mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sports activities. with the support of multimedia technology and the integration of sports and tourism industry, china's ice and snow leisure sports can be better developed, providing greater development space for the development of china's ice and snow sports tourism [1]. 2. development of ice and snow sports tourism in china ice and snow sports tourism first appeared in europe, and developed and expanded in european and american countries. based on rich ice and snow resources, it attracts more ice and snow sports fans to actively participate in ice and snow sports and leisure projects, and ultimately achieve the goal of physical fitness and happy mood. ice and snow sports tourism is to develop ice and snow sports projects according to the existing ice and snow resources, guide tourists to participate in them, so that athletes can release their emotions. ice and snow sports tourists are connected with ice and snow resources tourism sites and society in the process of participating in ice and snow sports exercises and competitions. since china has won the chance to host the 2022 winter olympic games, the enthusiasm of the ice and snow sports tourism market has risen unprecedentedly, which has made the construction and layout of ice and snow sports tourism constantly improved. under this background, the relevant national departments have issued relevant measures to ensure the gradual improvement of the ice and snow sports industry as far as possible, fully create a better external development environment for the development of ice and snow sports tourism, and enable the government to play its guiding role. after being valued by all aspects of society, ice and snow sports also attract more forces to participate in the ice and snow sports industry. china attaches great importance to the development of the ice and snow sports industry. ice and snow sports tourism is an important component of the ice and snow sports industry and a major way to attract people to participate in ice and snow sports. it is necessary to provide a better development environment for the development of ice and snow sports tourism. ice and snow field resources are an important basis for the development of ice and snow sports tourism. on the basis of the accelerated development process of ice and snow sports, the number of ice and snow fields in china has also been increased. the strength of all aspects of society has improved the quantity and quality of ice and snow fields. with the specific presentation of the economic benefits of ice and snow sports tourism, ice and snow sports tourism has also expanded to more areas. the number of provinces and cities implementing ice and snow sports tourism activities in china has increased, and gradually become a new economic industry. the ice and snow sports tourism industry can help optimize the development of china's economic structure, and the national and social capital theory has also increased the construction of ice and snow venues and resources. with the development of information technology in china, multimedia technology has been widely used in many fields, and the popularity of multimedia technology in china has also been generally improved. in the process of social development, the emergence of multimedia technology has also led to new forms of life in society. combined with the data information of china's internet information center, the size of internet users in china has reached six hundred million, the internet penetration rate is high, and the equipment of internet users in china mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset is more diversified. mobile internet has also become an important reason for the increase in the number of internet users. the good development trend of multimedia technology makes ice and snow sports tourism face more development opportunities. the ice and snow sports tourism industry will also be able to build a better ice and snow sports tourism mobile platform based on multimedia technology for better development. with its advantages, it will carry out a variety of innovative models such as personalized and professional services, promote the deep integration of multimedia technology and ice and snow sports tourism, and thus cultivate a modern ice and snow sports tourism model [2]. 3. factors restricting the development of ice and snow sports tourism in china 3.1. higher professional requirements for relevant professionals skiing and skating are both dangerous. when china's ice and snow sports tourism is developing rapidly, the increase in the number of tourists shows that the management level of the scenic spot is obviously insufficient, which makes the management level of the staff in the scenic spot need to be further improved. the increase in demand for ice and snow tourism requires high professional ability of the staff. china's training of innovative talents in sports tourism is relatively insufficient. the training mode of comprehensive talents cannot meet the wide application of multimedia technology, and the service quality of ice and snow sports tourism is also obviously poor. while developing the ice and snow sports industry, it is necessary to cultivate high-quality talents with professional skills of ice and snow sports. ice and snow coaches and snow makers are important factors for the development of the ice and snow tourism industry. our country has relatively insufficient talent training power for ice and snow sports. the degree of integration of ice and snow sports and tourism industry is not high, and the number of composite talents is not large, so we need to pay attention to them. 3.2. the penetration rate of ice and snow population is relatively low when measuring the national penetration rate of skiing, it is mainly to observe the ratio between the total number of skiers and the total number of skiers. there is still a certain gap between the penetration rate of skiing in china and that in developed countries. in most cases, the enterprise managers of ice and snow tourism destinations take "market share" as the standard to measure the development of enterprises, and pay less attention to the product connotation. in china, there are not many ice and snow sports venues and facilities, and the overall service level also needs to be improved. the ice and snow sports tourism industry contains only a few types of products. the existing products and brands cannot meet the needs of highquality sports tourism consumption, which is also an important factor in the low penetration rate of ice and snow population. 3.3. inadequate understanding of ice and snow sports tourism the development and popularization of ice and snow sports tourism need a long process. ice and snow sports tourism is a kind of activity with high consumption, which is related to people's consumption level and consumption consciousness. however, the current public awareness of ice and snow sports tourism is not sufficient, the interest and attention of ice and snow sports tourism is not high, and a more effective concept of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ice and snow sports and tourism consumption has not been formed. the consumption of ice and snow sports tourism is limited. 4. application of multimedia technology in ice and snow sports tourism multimedia technology is a technology that enables users to carry out real-time information interaction with computers through a variety of senses on the basis of computer's comprehensive processing and management of text, image, animation and other multimedia information. multimedia technology is also known as computer multimedia technology. the application of this technology to ice and snow sports tourism has a positive impact on the development of ice and snow sports tourism. 4.1. optimize talent training mode by using multimedia technology in the internet era, the integration of internet platforms and big data technologies with various industries has gradually deepened, and multimedia technology has also become an important driving force for the development of ice and snow talent training. the large-scale related technologies of ai technology and big data driven technology are promoting the reform of education and training models. by using multimedia technology, more mathematical scenes have been expanded, making the traditional teaching model gradually transform into a model of information content sharing [3]. at the same time, we will learn from and draw on the management and training experience of advanced snow sports talents at home and abroad, fully meet the current domestic demand for snow and ice talents, and effectively improve the training level of snow and ice talents. 4.2. customizing ice and snow sports tourist services with digital technology with the increase of the number of ice and snow sports tourists, groups of all ages have become important participants in ice and snow sports tourism activities. the span of age levels is also larger, which brings challenges to the service level of scenic spots to a certain extent. traditional services have no way to meet people's needs. when building the ice and snow sports tourism digital service platform, analyze the data information of users' personal needs to achieve personalized services, so that tourists can get more information about ice and snow sports tourism, and quickly carry out the positive interaction of various sectors to improve tourists' tourism satisfaction. in addition, the multimedia platform has become the direction of ice and snow tourism market development, select unqualified tourists based on intelligent devices to ensure the safety of tourist groups. when multimedia technology enables tourist services, the transformation of thinking mode should be applied to finally realize the intelligent and scientific operation of the ice and snow sports tourism industry and the high-quality and quantitative development of services, meet the needs of industrial innovation and development, improve the satisfaction of tourism groups, and attract more tourists. 4.3. use multimedia technology to enrich the participation mode of ice and snow sports tourism multimedia technology enriches the participation mode of ice and snow sports tourism, builds an ice and snow simulation system supported by multimedia technology, realizes the virtual implementation of ice and snow tourism, effectively promotes the digitalization of ice and snow resorts under the support of a simulation system mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset composed of a control system, a multimedia system and other multi-function systems, and fully meets the needs of ice and snow sports tourists while improving their ski technology, in addition, it can effectively realize the real reproduction of the scene, provide snow simulation and other related resources for regions with insufficient snow and ice resources, and provide intelligent support for the overall process of skiers. at the same time, we should enrich the types of ice and snow tourism activities. in the form of participation in various types of ice and snow sports tourism, we should combine digital technology to meet the market's personalized demand for ice and snow sports tourism, so that ice and snow sports tourism will not be limited by ice and snow resources, and provide tourists with the necessary fun of ice and snow sports tourism activities through scientific and technological means. 4.4. using multimedia technology to improve the operation and management intensity of ice and snow sports tourism in the context of the extensive application of multimedia technology, the development of ice and snow sports tourism activities needs to improve the coordination ability, and the coordination ability needs not only to focus on the improvement of the internal coordination ability of ice and snow sports tourism management, but also to clearly connect external factors. by building a multimedia digital platform for ice and snow sports tourism, the comprehensive management of ice and snow sports tourist attractions will be carried out to a greater extent from all aspects. during the safety management of ice and snow sports tourist attractions, humidity modules, temperature modules and lcd modules are installed inside the scenic spots to better understand the activity routes of passengers. the multimedia platform can shorten the safety warning time to a greater extent and fully improve the management efficiency of ice and snow sports tourist attractions. at the same time, based on the customized 5g+ar immersive intelligent crowd guidance service system and 360 degree panoramic image acquisition technology, tourists can solve the problems existing in the process of sightseeing, so that tourist groups can understand the actual situation of the site and the passenger flow, and tourists can choose the appropriate site according to their own level. in the process of supporting service management, the integration of infrastructure and services, independent software developers and other aspects should be combined to better create an offline data integration approach, promote the combination of online platforms and offline tourism, and further expand the function of ice and snow sports tourism. in the multimedia platform, tourism groups can get the dynamic information content of ice and snow sports tourism destinations, such as navigation, shopping guide, catering and accommodation, under the support of multimedia technology, we will carry out activities such as buying tickets and entering the park, solve the problem of insufficient human resource allocation in each scenic spot, and improve the overall management level of the scenic spot. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4.5. insist on market demand orientation and deeply develop new products in general, the development of ice and snow sports tourism products is from the whole process of product marketing and consumption. ice and snow sports tourism scenic spots should also pay full attention to the added value of ice and snow sports tourism products, build a well-known ice and snow brand, make full use of short videos, wechat platform and other multimedia boxes to promote ice and snow sports tourism products, and realize the publicity of ice and snow sports tourism products in multiple directions. under the background of market demand, develop ice and snow sports tourism products such as chemistry and ice and snow fishing, fully meet the spiritual needs of tourists, enhance product supply, and to a greater extent enhance the added value of the ice and snow sports tourism industry, making the ice and snow tourism industry chain more rich. 5. conclusion the maturity of multimedia technology can also provide the basic conditions for the construction of the ice and snow sports tourism industry internet, while changing the development mode of the ice and snow sports tourism industry. the highly developed information technology-based ice and snow sports tourism industry provides a perfect network chain. this network relationship is not an economic entity in the legal sense, it does not have the legal personality, but needs to break through the boundaries between traditional enterprises, form an internet model of integrated development. the internet transformation of the ice and snow sports tourism industry not only needs to adopt the multimedia management platform, but also needs to innovate and further improve the quality of the original products and resources, and needs to adjust the management structure between the ice and snow sports tourism projects and the various industrial units of the multimedia platform. under the support of multimedia technology, the advantages of the project are combined to fully meet the economic and social benefits of the ice and snow sports tourism project. in the era of multimedia, the speed of information transmission has been unable to be expected. under the new development background, sustainable development thinking is required. the combination of ice and snow leisure sports and tourism industry in china enables multimedia technology to promote the integrated development of ice and snow leisure sports and tourism industry. during the application of multimedia technology in ice and snow sports tourism projects, supported by the multimedia platform, the diversified and multi-dimensional publicity of the continuous output of ice and snow leisure sports culture enables the public to better receive information about ice and snow leisure sports culture through the all media platform, which enables multimedia technology to promote the construction of high-level composite talents with chinese characteristics and knowledge of ice and snow leisure sports and tourism industry, under the support of the multimedia platform, a multi-party information communication platform will be built in combination with internet technology to integrate ice and snow sports resources and tourism resources according to the characteristics of the region, strengthen infrastructure construction, and clearly expand the venues with ice and snow leisure sports functions that can be experienced by more consumers, so that the ice and snow sports tourism projects will be improved accordingly to better meet people's tourism needs. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references gu jiuxian. research on regional consumer demands and behavioral influence of the 2022 winter olympics— hebei winter sports tourism as example [j] sports & research, 2016, 37 (04): 114-120. shi shuqi. research on the application of new media in the winter olympic games -a case study of "snow and ice in china" app [c] //. compilation of papers of 2017 science and technology winter olympic forum and sports science and technology product exhibition. [publisher unknown], 2017: 7779. tong gang. exploration on the construction of national snow and ice sports culture under the background of the dream of strengthening china [j]. snow and ice sports, 2015, 37(04): 64-67+84. mailto:topacademicjournals@gmail.com 060912-fp0332-academic journal of engineering and technology science-加急.docx academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset tackling cable grounding problems: a comprehensive optimization investigation huang, pei-yin state grid beijing cable company, beijing, 100022, china abstract: the underground positioning of urban area cables presents a unique challenge in detecting and addressing grounding faults. this study delves into the classification reasons for grounding faults in urban cables and equips power personnel with essential techniques, analysis methods, and advanced countermeasures. detecting and addressing grounding faults promptly is crucial for enhancing cable operation efficiency and fault handling speed, aligning with the overarching goal of cost reduction and efficiency enhancement in power engineering operations. this research aims to maximize profits while optimizing maintenance and daily operation efficiency. keywords: grounding faults, urban area cables, fault detection, maintenance techniques, efficiency enhancement 1. introduction the cables in the urban area can basically be said to be located in the basic underground position of the entire urban area. due to the unique reasons for laying these types of cables, it is not particularly easy to find the faults that occur when there are grounding faults in the cables, and to carry out corresponding correct and timely maintenance. therefore, it is necessary for relevant power personnel to understand and learn the main classification reasons for grounding faults in cables, and master the relevant main search techniques, corresponding analysis methods, and advanced countermeasures[1-2]. at the critical moment, when the corresponding cable has a grounding fault, it can accurately find out the specific and accurate fault points of the relevant cable, it can also improve the actual operation efficiency of the cable and the corresponding speed of fault handling. it can achieve real and timely fault repair response, thoroughly implement the main concept of cost reduction and efficiency increase in the operation and maintenance of power engineering. at the same time, it can also maximize the profit maximization of the maintenance and daily operation of power engineering while improving physical efficiency [3]. 2. the main types of cable failures in today's society, the short circuit faults of power cables that we can come into contact with can be roughly divided into the following four common situations [4]. a) the first scenario is a fault caused by the insulation of single-phase or multiphase conductors to ground, which causes high resistance, low resistance, and high metallicity. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset b) the second scenario is a fault caused by a broken wire. during the operation and maintenance of highvoltage power cables in daily operation, if a wire break occurs in the single-phase or multiphase conductor parts of the cable, it can directly reduce the direct and indirect stability of power cable supply. c) the third scenario is a flashover fault. this type of fault is a special type of fault where the power cable itself is suddenly broken down by high voltage during overload operation, and then returns to its original state to continue operation. d) the fourth type is a composite fault. this refers to the occurrence of various types of faults in high-voltage power cables during operation. the above four situations can summarize the main factors and specific causes of cable faults in current power engineering, and can be said to be a highly valuable classification for reference. 3. analysis of the main grounding faults in cables in current power engineering cables in urban power engineering are generally laid underground in urban areas, while urban underground pipelines are usually complex and limited in space. if the surrounding area of the power grid project is excavated again after the successful completion of the specific cable laying in the power engineering, and other specific activities of power engineering construction are carried out, power workers or other types of workers are very likely to damage the cables, causing some special cable grounding comprehensive faults[5-7]. the production of cable joints in power engineering is actually very convenient and easy to operate, but due to this reason, some power engineering construction units do not attach importance to the specific local construction quality of welding and other links. in the actual welding process of grounding wires, there are often violations of regulations and operations. in addition, some power engineering technicians have limited welding capabilities and are concerned that the cable insulation may be burned during the welding process. therefore, they have replaced complex welding processes with simple steps such as binding, which can easily cause abnormal loosening of the grounding wire and copper tape shielding layer of high-voltage power cables, laying a significant safety hazard for the safe operation of future power engineering[8]. in areas with special geological conditions such as coal mines and mining areas, the grounding grid is a composite of shielding layer and sheath of cables and low-voltage cables due to construction conditions. in this special situation, accidental cracking of the metal shielding layer of highvoltage cables or accidental detachment of the cable grounding wire can also cause grounding faults in highvoltage cables. for high-voltage cables, the copper strip shielding layer is usually single core and three core, and manufacturers must use fusion welding technology or copper welding technology to fix the copper strip connection when producing cables, in order to barely meet the basic industry process standards[9-10]. however, in the actual production process of power engineering, some power suppliers and manufacturers still use simple traditional processes such as soldering to make cables, and then overlap them and fix them with plastic bags. this is clearly an irresponsible and non compliant production behavior habit, these extremely irresponsible behavior habits have also laid the groundwork for safety hazards and major safety concerns in the future occurrence of cable grounding faults[11]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. test method and optimization application of cable grounding fault electric power employees should make accurate judgments, timely detection, and maintenance of various problems caused by cables, whether due to external factors or their own reasons. common testing methods for grounding fault points include but are not limited to the following three types[12]. a) cable low resistance grounding fault. this type of fault refers to a low insulation resistance of one core wire of a cable to ground, but good continuity of the core wire. therefore, this type of fault has the characteristic of strong concealment, and can be tested by using circuit fixed point transmission. b) two phase short circuit fault. when it is being measuring, you can use any faulty core wire as the grounding wire and connect the other faulty core wire to the bridge. the calculation formula and measurement method are the same as for single-phase low resistance grounding faults. c) three phase short circuit fault. during measurement, it is necessary to borrow other parallel circuits or install temporary circuits as circuits. a high resistance grounding fault in a cable refers to the insulation resistance value between the conductor and the aluminum sheath or conductor, which is much lower than normal resistance, but is higher and the continuity of the core wire is good. this type of fault can be measured using the high-voltage bridge method. d) due to the high current at the fault point, it is necessary to use a high-voltage dc power supply to ensure that the power supply passing through the fault point is not too small. flashover fault. this type of fault shows good insulation resistance of each phase and good wire continuity, so it can be roughly concluded that each fault point has been closed. 5. comprehensive optimization of cable search methods we will compare and analyze the mainstream grounding fault detection measures one by one.the bridge method, which is mainly used in current power engineering, is mainly based on the principle of double arm bridges for detection. we can accurately short-circuit the fault phase of the high-voltage cable to be detected with the non fault phase of the high-voltage cable, forming a closed connection circuit. at the same time, we can adjust the position of the bridge's double arm resistors with adjustable properties in a timely manner. in this way, when the bridge is in a balanced state, the resistance product values on both sides of the bridge arm will be equal, and then the corresponding fault distance will be measured using the positive proportional relationship between cable length and resistance. the personnel involved in the relevant power engineering have preliminarily determined that the fault in this section of the line belongs to a broken line fault. this way, the staff can scientifically test the transmission line using a professional cable fault tester based on the principle of a double arm bridge. after the staff excavates, the actual fault location confirmed on site is consistent with the bridge detection results. direct flash method is an abbreviation of dc high-voltage flashover detection method, which is very effective in measuring flashover breakdown faults. in the specific routine testing process, it utilizes professional high-voltage power cable fault detection instruments to apply the continuously increasing dc voltage of the cable to the highvoltage cable being tested before the fault resistance value is too high and the resistance channel is truly formed. in this way, when the voltage reaches a specific value, the cable fault point will be broken down by the highvoltage load, forming a cable flashover. then, through the influence of flashover arc, the corresponding voltage mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset undergoes short circuit and open reflection. in this way, under multiple reflections between the fault point and the input end, the electrical energy will be completely consumed. the impulse flashover method, also known as the impulse high-voltage flashover method, has a wide testing range and is suitable for testing many high-voltage cable flashover faults. its application method is roughly similar to the dc high-voltage flashover method, except for adding a spherical discharge chamber between the cable and the capacitor. when the capacitor is charged and the voltage rises to a specific value, the ball shaped discharge will occur breakdown discharge. after the cable line obtains an instantaneous high voltage, if the instantaneous high voltage is higher than the critical breakdown voltage at the fault location, the corresponding fault location will generate breakdown discharge phenomenon, and the current and voltage signals will be transmitted to both ends instantaneously. when the staff receives this signal, they can measure the length of the fault. there are many signal sampling methods for the impulse flash method, and the most common ones should be the current sampling method and the voltage sampling method. especially the second type of voltage sampling method has strong anti-interference and accurate testing. due to this reason, its application is also more common, which reflects its strong applicability and universality. 6. other mainstream fault finding methods the low-voltage pulse method is mainly used for testing short faults, open circuit faults, and low resistance faults in high-voltage cables in power engineering activities. in addition, it can also measure the length of cables and the propagation rate of electromagnetic waves. moreover, through the lowvoltage pulse testing method, the staff can accurately distinguish the joints, terminal positions, and intermediate positions of high-voltage cables. in the specific testing, the staff needs to inject a lowvoltage pulse into the high-voltage cable in advance. when the pulse encounters a short circuit point, intermediate joint, or fault point during the propagation process inside the cable, it will generate corresponding pulse reflection. afterwards, the reflected signal will propagate to the measurement point, and the measuring instrument will accurately record it accordingly. the principle of the low-voltage pulse method is simple and does not require a high-voltage pulse generator, so it is relatively easy to implement. moreover, this method only needs to know the propagation speed of the pulse in the cable, and can display the waveform collected by the low-voltage pulse on the lcd screen, thereby mastering the situation of various joints inside the cable. however, when encountering high resistance faults and flashover faults, the reflection pulse of the low voltage pulse is very small and difficult to detect, so it is not applicable. the sound wave method is generally applied to flashover ground faults and high resistance ground faults, mainly using high-voltage pulse generators to complete fault point testing. during the specific testing process, the staff needs to emit high-voltage pulses into the corresponding high-voltage power cable. when the high-voltage pulses are transmitted to the fault point, they will release huge energy to instantly break through the grounding point and emit a brief sound. then the installed pickup will amplify the sound, so that the staff can accurately determine the grounding fault point of the highvoltage cable. the cable burning through method mainly relies on professional cable burning through instruments to emit high-voltage small currents into the corresponding high-voltage faulty cables, thereby maintaining the high-voltage cables in a short-circuit heating state. in this way, the external insulation layer of the cable will experience aging and carbonization under high heat, and the staff can immediately accurately identify mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the relevant cable fault points. because the nature of the cable fault is a high resistance fault, the staff cannot accurately test its fault point through pulse detection. 7. conclusion overall, the application of power engineering cables not only does not affect the aesthetics of normal urban environments, but also greatly facilitates the daily electricity consumption. and due to its advantages in underground power transmisson, work and life of ordinary residents in urban areas become much better. however, the problem that arises from this is that finding cable faults in power engineering is a highly challenging engineering task. for different mainstream types of cable faults in power engineering, there are also significant differences in the troubleshooting techniques and methods adopted by maintenance personnel in power construction. due to the occurrence of this situation, it requires relevant power engineering personnel to fully combine their rich search experience in the practical search process, and flexibly switch to fault search techniques in a timely manner. only in this way can relevant fault points be quickly and accurately identified, and the occurrence of safety accidents in related power engineering can be efficiently avoided. references liu haikang, liao yanqun, xu xiaobing. combining bayesian inference with weibull proportional risk model reliability analysis method for pressure cables [j] high voltage technology, 2021, 47 (2): 546-554 shu hongchun, zhu mengmeng, huang wenzhen, et al. fault line selection method for distribution networks based on transient zero sequence current time-frequency characteristics [j]. power automation equipment, 2013 (09): 5-10 zhang wenhui. single phase ground fault detection method and application of distribution network [d], north china electric power university, 2013 dong lei, he lin, pu tianjiao. the impact of neutral grounding methods on the reliability of distribution networks [j]. power system protection and control, 2013 (01): 103-108 cui xiaoguang. fault detection technology for 220kv high-voltage power cables [j] low carbon world, 2020, 10 guo huan. common fault analysis and preventive measures for 110kv cable lines [j]. electrical technology, 2020, 12 li chuanjian, sun jianing, hu qingshan, et al. research and implementation of a single-phase grounding fault simulation test platform for distribution networks [j]. mechanical and electrical engineering technology, 2015 (09): 129-133182 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fu xiaoqi. research on application of neutral point small resistance grounding technology in urban 10kv distribution network [d]. north china electric power university, 2014 zhang qingbo, teng yihai, pan donghui. the single-phase grounding fault of the 35kv collection line has expanded to the grounding transformer event analysis of device protection skip action [j] solar energy, 2020 (12): 62-65 yang lu. analysis and treatment of grounding circulating current faults in power cables [j]. chinese high-tech enterprise industry, 2017 (10): 95-96 wang yanwen, zhao yongmei, li junfeng, et al. on line insulation of high-voltage cables for mining based on wams monitoring method [j]. coal science and technology, 2016 (s2): 146-149 wang yongsheng, li xiaona, zhao guodong, et al. research on online monitoring of high voltage cable insulation in coal mines [j].mining automation, 2016, 42 (6): 65-69 mailto:topacademicjournals@gmail.com 060904-fa2057-academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset enhancing new energy vehicle reliability: electronic diagnosis of battery voltage faults lin, jia-wei school of automotive engineering, guangdong polytechnic of science and technology, zhuhai, guangdong, china abstract: the emergence of new energy vehicles (nevs) has revolutionized the transportation sector by offering a sustainable and environmentally friendly alternative to traditional fuel-driven vehicles. nevs have demonstrated remarkable potential in reducing energy consumption and curbing exhaust emissions, thereby contributing to the advancement of a more sustainable society. this burgeoning industry, while promising, presents unique challenges in terms of maintenance and fault diagnosis, necessitating innovative approaches to address these evolving requirements [1]. in this context, this study delves into the application of electronic diagnosis technology for the precise identification of battery voltage faults in nevs, aiming to foster the continued growth of the nev sector. keywords: new energy vehicles (nevs), battery voltage fault diagnosis, electronic diagnosis technology, maintenance technology, sustainable transportation 1. introduction new energy vehicles are innovative products in the field of clean energy application, which solves the problem of high energy consumption of vehicles using fuel to drive. new energy vehicles reduce energy consumption, reduce exhaust pollution, and promote the sustainable development of society. the new energy vehicle industry has bright development prospects and broad space for development, while it also puts forward new requirements for automobile maintenance technology [1]. we should explore the new technology of fault diagnosis and maintenance of new energy vehicles, especially the use of electronic diagnosis technology for the battery voltage fault diagnosis, to help the development of the new energy vehicle industry. based on electronic diagnosis technology, the new energy vehicle battery voltage fault diagnosis can be analyzed by various kinds of electronic devices, which can help understand the running state of any components and parts in the battery, find out the abnormal situation in time, and achieve accurate positioning and processing of faults. automobile maintenance technology can help complete diagnosis and maintenance in a short period to eliminate the use of new energy vehicles. 2. maintenance challenges under the background of new energy vehicle application china has a certain time and experience basis for the research of new energy vehicles. as early as 1980, china began to research this aspect. by the end of 2021, china's export volume of new energy vehicles has exceeded 10,000, accounting for 10.7% of the total export volume of all vehicles. in the continuous development, new energy vehicles have gradually become an important part of the development of automobiles, playing an important mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset role in the domestic automobile manufacturing industry. at present, the use of new energy vehicles in china ranks relatively high in the world, which is expected to open up the international market of new energy vehicles. compared with the total sales volume of new energy vehicles in 2021, the sales volume increased by 1.5 million units in 2022. with the wide application and development of new energy vehicles, the battery, as its core energy storage device, has higher and higher requirements for its performance and reliability. however, in the process of long use of the battery, there may be voltage failure, resulting in its performance decline or failure. this result can affect the endurance and reliability of new energy vehicles. to effectively solve this problem, electronic diagnosis technology has been introduced into the maintenance of battery voltage faults of new energy vehicles, providing maintenance personnel with more accurate, fast and reliable fault diagnosis and repair methods. from the perspective of practical application, electronic diagnostic technology will regard electronic equipment as the main carrier, and will directly inspect the interior of the car without any disassembly. 3. overview and application advantages of electronic diagnostic technology information electronic diagnosis technology is a kind of use of computer, network and sensor information technology means to automobile fault diagnosis and repair technology. it connects the vehicle's electronic control unit (ecu) to read the vehicle's fault code, sensor data, and real-time parameters, as well as provide fault descriptions and suggestions. through diagnostic software and tools, technicians can conduct fault analysis, fault location and maintenance operations to improve maintenance efficiency and accuracy. information technology and electronic diagnostic technology has many advantages in the maintenance of new energy vehicles. first, it can improve the accuracy of fault diagnosis. by reading the fault code and real-time data of the vehicle, diagnostic technicians can quickly and accurately determine the fault location and cause, avoid guessing and trial and error, and improve the accuracy of fault diagnosis. second, it can improve maintenance efficiency [2]. information electronic diagnosis technology can quickly obtain the relevant information of the vehicle, assist the technical personnel to conduct fault analysis and judgment, accelerate the speed of fault positioning and maintenance operation, and improve maintenance efficiency. third, it can provide maintenance guidance and solutions. diagnostic software and tools not only provide fault codes and data but also provide detailed repair guidance and fault solutions to help technicians better repair operations and reduce errors and omissions. fourth, it can improve data recording and analysis. information electronic diagnosis technology can record the fault data and maintenance records of vehicles, provide a reference and analysis basis for the subsequent maintenance work, and help improve the maintenance process and technology. fifth, it can improve customer satisfaction. through accurate fault diagnosis and efficient maintenance operation, information electronic diagnosis technology can provide high-quality after-sales service, improve customer satisfaction and enhance brand image [3]. 4. current status of new energy vehicle battery fault diagnosis for electric vehicles, the degree of safety damage to the battery system determines the probability of operational failure. to ensure the accurate diagnosis of faults, the fault type needs to be identified in advance, and the safety failure of the battery system in actual use is mainly divided into two aspects: mechanical failure and electrical failure. in the process of operation, it is the main source of the mechanical failure of the battery system. after the mechanical failure of the battery system, the deformation of the battery makes the internal gas electrolyte mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset overflow, leading to the bulging phenomenon of the battery. meanwhile, the internal resistance of the battery increases the heat production. in this process, if the heat is not effectively distributed, fire and explosion accidents can occur; when the battery system is overcharged, internal short circuit and external short circuit cause electrical failure, the battery temperature triggers internal diaphragm melting, electrolyte decomposition, cathode material decomposition, and serious accidents such as battery leakage, fire and explosion. fault diagnosis and positioning method based on battery-end voltage signal are usually divided into model-based method and data-driven method. based on the model method, the battery equivalent circuit model is first established, and then analyzes the difference between the model output and the observed value. this method usually follows some basic principles. when battery failures occur, the internal resistance will always increase rapidly, or the terminal voltage will decrease rapidly, which is difficult to preset the appropriate failure threshold. the model-based fault diagnosis method relies on the sample data to avoid the online parameter update of the battery model. electronic diagnostic technology is one of the model-based fault diagnosis methods. it uses intelligent detection methods to do a full range of detailed problem inspections of the car, which can help the technical repairman to quickly find the problems of the car according to the accurate data provided to make reliable maintenance decisions, which can ensure high efficiency and high quality of maintenance [4]. as a new maintenance detection technology, electronic diagnosis technology has achieved good promotion effect in maintenance engineering with its high-quality detection effect. by this, it turns traditional manual troubleshooting into electronic and accurate troubleshooting. 5. application of electronic diagnosis technology in battery fault diagnosis of new energy vehicles for new energy vehicles, the key to promoting their normal operation is the power battery, and the operation efficiency and quality of power batteries will directly affect the operation efficiency and quality of new energy vehicles. in the new energy vehicle power battery, there are two main types, one is a storage battery, and the other is a fuel cell. storage battery is more common, including lithium batteries, lead-acid batteries, nickel-based batteries, etc. because the principle framework of power battery is more complex, the maintenance cost is relatively high, through the use of electronic diagnostic technology. under the action of various intelligent equipment and systems, it can dynamically detect the overall situation of the power battery, find out the fault problem according to the obtained parameter information, and deal with it in time, for example, the sudden stalling of new energy vehicles. in general, the basic cause of the phenomenon cannot be ascertained in time. through electronic diagnosis technology, the operation of the battery can be dynamically tracked. with its simulation function, the temperature change of the battery during the operation can be understood. if the temperature of the battery is abnormal, the cause of the fault is the battery. through the maintenance treatment plan, the power battery in the operation of the fault problem in time to prevent the same problem from appearing. the power battery management system includes the battery management system, control module, display module, wireless communication module, etc. the detection sensor in the battery pack can monitor the internal temperature, voltage, internal resistance and other parameters of the vehicle battery in real time, and feedback the obtained data and information to the power battery management system. in vehicle maintenance processing, the use of electronic diagnostic technology, according to the data information obtained by the driving computer, to master the working environment temperature of the battery. generally speaking, the battery temperature shall not exceed mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 50 ℃, and the minimum temperature shall not be less than 0 ℃. therefore, to maintain the normal performance of the battery, it is necessary to monitor the temperature of the battery in real time. 6. battery voltage fault diagnosis mechanism of new energy vehicles based on electronic diagnosis technology voltage fault diagnosis of new energy vehicle battery based on electronic diagnosis technology is mainly using electronic diagnosis technology from the distribution copper row, battery interior, voltage wire harness, circuit, battery daily maintenance for battery repair and maintenance. this is also the basic content of the construction of the battery voltage fault diagnosis mechanism of new energy vehicles based on electronic diagnosis technology. 6.1. power distribution copper exhaust fault maintenance new energy vehicles use positioning bolts to fix the battery pack and power distribution copper row for fault maintenance. the distribution copper row obtains the single battery voltage in a crossway, which is transmitted to the power controller by a single or more channels. the positioning bolt will follow the resonance of the vehicle in driving, fall off, or the force impact causes the bolt to skew. this can not play a fixed role, causing the multicell battery voltage jump and the battery voltage imbalance when the power is directly interrupted. in the detection process, the cloud electronic file information can be analyzed to clearly check the last operation and maintenance time of the vehicle, and check whether there is a major impact accident. if there is a fault, even if the detection equipment does not send alarm information, the staff needs to check the bolt for loosening one by one [5]. 6.2. internal fault maintenance of storage battery because the battery is assembled by multiple single batteries in series and parallel, the small impurities between individuals and individuals will also cause the internal resistance failure of the cell, resulting in abnormal voltage. at the same time, if the vehicle does not start for a long time, the battery will discharge slowly with time, and the voltage value will be abnormal. if the electronic diagnosis results show that the voltage of any block is too low or too high, the single battery is recharged. if the voltage remains abnormal after charging, then the abnormal phenomenon is caused by small impurities, and the battery module should be replaced. if it can be restored to normal, the abnormal phenomenon is caused by the self-discharge, and the battery can be recharged slowly. it should be noted that the new energy vehicles should be placed in the correct charging position of more than 0℃ for charging. if the charging pile temperature is too low, it will not be able to transport energy to the vehicle, so the owners in the areas where the temperature is lower than 0℃ in winter should charge the car immediately after parking. 6.3. pressure harness fault repair the voltage wiring harness serves as a battery temperature and residual power information collection tool. if the fault occurs, the vehicle itself detection system will not be able to carry out dynamic transportation and inspection of the internal situation, which is easy to cause safety accidents. the main causes of voltage failure caused by abnormal voltage wire harnesses are: lax contact between the wire harness and the battery pack, short circuit, open circuit or series connection [6]. at the same time, compared with the normal automotive electronic components, the number and precision of new energy electronic components are much higher, but the voltage is very small. when there is a fault in the voltage wiring harness, there will be problems with the overall circuit. for mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset this reason, the fault detection device of electronic diagnosis technology can be used to insert the two ends of the wire harness to determine whether the port has return needles. the short circuit, open circuit or series problems of the wire harness itself are usually due to the unreasonable arrangement of copper wire in the line, so the wire compression shall be replaced. 6.4. circuit fault maintenance in order to optimize the function of the vehicle, users of new energy vehicles will add other electronic devices, which increases the burden of batteries and is easy to cause faults. therefore, it is necessary to insert the circuit detection system into the detector. if the abs alarm lamp flashes constantly, there is a circuit fault. the maintenance personnel need to record the current voltage of the battery through the universal meter, compare with the flashing frequency of the alarm light, get the fault code, and find out the electronic device that causes the voltage fault. after removing the device, it needs to insert the detection system again to check if the abs alarm light flashes or not. 6.5. daily maintenance of the storage battery maintenance personnel should guide the user to charge and use electricity correctly. if the voltage is too low or excessive charging, the battery life will be lost. focus on checking whether the low soc warning lamp can work normally. when the vehicle is near the low soc, it can timely alarm to remind the user to find the charging device. it needs to inform the owner to adjust the interval between of battery maintenance through the fault alarm instrument panel and braking power force and carry out charge and discharge training every 3 months. if the power consumption is higher than the last test, it will need to go to the nearest logistics maintenance shop for electronic diagnosis to check the battery voltage fault. if the vehicle is not used for a long time, the owner needs to charge on time to ensure that the battery is always in a state of non-power loss. in the process of repair and maintenance, the staff must cut off the power supply. after repairing the voltage fault, the original voltage wiring harness and power distribution copper row position should be restored. when the installation is completed, the plug part should be slightly pulled to prevent the occurrence of bad contact problems. at the same time, maintenance personnel also needs to do a good job of waterproofing and dust prevention, to avoid external impurities and water vapor infiltration into the battery. in this way, all the work of battery voltage fault detection and maintenance is completed and uploaded to the cloud to provide a data basis for the next operation and maintenance. 7. conclusions differential fault detection and maintenance technology based on electronic diagnosis technology is a necessary means for the operation and maintenance of new energy vehicle batteries. through real-time monitoring and diagnosis of battery voltage combined with advanced electronic technology and fault positioning algorithm, it can accurately determine the cause and location of voltage fault, and provide the corresponding maintenance scheme. electronic diagnostic technology can not only improve the efficiency and accuracy of new energy vehicle battery fault diagnosis and maintenance but also reduce the maintenance cost and improve the reliability and market competitiveness of new energy vehicles. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 6; november december 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset acknowledgement scientific research project of guangdong polytechnic of science and technology "development of vehicle charger based on soft switching technology" (xjpy202201) references gan, n., sun, z., zhang, z., xu, s., liu, p., & qin, z. (2021). data-driven fault diagnosis of lithium-ion battery overdischarge in electric vehicles. ieee transactions on power electronics, 37(4), 4575-4588. wu, c., zhu, c., & ge, y. (2017). a new fault diagnosis and prognosis technology for high-power lithium-ion battery. ieee transactions on plasma science, 45(7), 1533-1538. wu, c., zhu, c., ge, y., & zhao, y. (2015). a review on fault mechanism and diagnosis approach for li-ion batteries. journal of nanomaterials, 2015, 8-8. liu, p., sun, z., wang, z., & zhang, j. (2018). entropy-based voltage fault diagnosis of battery systems for electric vehicles. energies, 11(1), 136. hu, x., zhang, k., liu, k., lin, x., dey, s., & onori, s. (2020). advanced fault diagnosis for lithium-ion battery systems: a review of fault mechanisms, fault features, and diagnosis procedures. ieee industrial electronics magazine, 14(3), 65-91. li, x., & wang, z. (2018). a novel fault diagnosis method for lithium-ion battery packs of electric vehicles. measurement, 116, 402-411. mailto:topacademicjournals@gmail.com 060905-fa2059-academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset elevating classroom dynamics: simulated velocity experiments in physics education 1yiming 1wang, xiaojun li, 2meixuan zhang and 2jiaxin liu 1high school of inner mongolia normal university, hohhot, inner mongolia, china 2second high school of hohhot, inner mongolia, china abstract: the continuous advancement of the new curriculum reform has brought about a significant shift in high school physics education, placing a growing emphasis on the use of demonstrations and group experiments. high school physics education encompasses a plethora of experiments that contribute significantly to both the development of physics knowledge and the evolution of pedagogical methods in physics education. the integration of physics demonstration experiments within the classroom setting not only equips students with essential skills for exploring physics concepts but also affords them deeper insights into the fundamental principles governing the physical world. this pedagogical approach fosters a heightened interest in physics, effectively transitioning from a passive teaching style to an active and engaging learning mode, thus augmenting the overall effectiveness of high school physics instruction. in tandem with these advancements, the rapid evolution of science and technology has led to the optimization and refinement of physics experimental equipment and experimental protocols, rendering high school physics classrooms more efficient and conducive to learning. this article endeavors to introduce a simulated apparatus tailored for physics velocity experiments, with the overarching objective of infusing vigor and enthusiasm into the physics classroom. this is achieved through a dual strategy that involves equipment enhancements and the optimization of experimental plans. keywords: high school physics education, physics demonstration experiments, active learning, physics experimental equipment velocity experiments 1. introduction with the continuous advancement of the new curriculum reform, high school physics education has increasingly emphasized demonstrations and group experiments. high school physics involves numerous experiments with rich content, significantly contributing to the development of physics and physics education. conducting physics demonstration experiments in the classroom helps students master the methods of exploring physics experiments and provides deeper insights into the essence of the physical laws being studied. this fosters students' interest in learning physics, transforming the previous passive teaching approach into an active learning mode, thereby enhancing the effectiveness of high school physics classroom teaching. with the rapid development of science and technology, physics experimental equipment and experimental plans have also been optimized and adjusted, making high school physics classrooms more efficient. this article introduces a simulated apparatus for physics mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset velocity experiments, with the aim of infusing the physics classroom with more vitality and making it engaging and enjoyable through equipment enhancements and experimental plan optimization. 2. problem statement physics is a discipline based on experimentation, and classroom teaching heavily relies on practical experiments. through experimentation, students can correctly observe the key characteristics of phenomena and obtain accurate representations, thereby enhancing their understanding of textbook content and mastering the knowledge they learn. one crucial aspect of physics experiments is velocity experiments, particularly those related to the relationship between velocity and mass. existing experimental apparatus for velocity simulation typically employ a dot timer and a track for sliding objects. however, these existing devices lack convenient adjustment of the track's angle, which limits the diversity of experimental data. additionally, placing the current apparatus directly at the edge of the experimental table can compromise its overall stability, especially when the traction force applied to the small car is significant. 3. development of the experimental apparatus 3.1. functional design of the experimental apparatus the purpose of this utility model is to provide a physics experimental apparatus for simulating velocity, aiming to address the issues identified in the prior art, such as the inconvenience of adjusting the track's angle, which affects the variety of experimental data, and the direct placement of the current apparatus at the edge of the experimental table, leading to stability issues. given the inconveniences in the existing technology regarding track angle adjustment, affecting the diversity of experimental data, and the stability problems associated with direct placement at the edge of the experimental table, the inventors conducted research to develop a physics experimental apparatus for simulating velocity. this apparatus involves using a u-shaped plate to fit around the edge of the experimental table, and then turning the knob to rotate a threaded rod, which clamps the bottom of the plate against the edge of the table. this allows for convenient positioning and fixation of the baseplate, facilitating its use. by rotating the handle, the threaded rod drives a driving block to move away from the axis direction along the baseplate, lifting the sliding rail at one end away from the axis. the sliding rail can be adjusted multiple times to different incline angles to obtain various velocity measurement data. the extension axis synchronously rotates with the sliding rail's rotation center, driving the pointer to rotate accordingly. the angle markings inside the marking slot facilitate quick adjustment of the sliding rail's incline angle. the overall device is easy to store and adjust, effectively addressing the aforementioned deficiencies. [1] 3.2. development of the experimental apparatus 3.2.1. working principle and structure the physics experimental apparatus for simulating velocity comprises a baseplate with a rotating shaft mounted at one end. a sliding rail is fitted on the rotating shaft, and an elevating component is installed between the sliding rail and the baseplate to adjust the incline angle of the sliding rail away from the rotating shaft. a positioning component is installed on one side of the baseplate to secure it in place. near the rotating shaft, the sliding rail mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset features wire holes, while the baseplate's end close to the wire holes is equipped with a wire mechanism for fixation. 3.2.2. components of the experimental apparatus the experimental apparatus includes the following components:(1) elevating component: it consists of a flipping frame connected to the baseplate for rotational movement, and the bottom of the flipping frame is connected to a threaded reciprocating mechanism.(2) threaded reciprocating mechanism: this mechanism includes a column fixed within the baseplate, with a threaded rod attached to it. one end of the threaded rod has a rotating handle, and the other end has a threaded block that fits tightly against the baseplate. the top of the threaded block is connected to the bottom of the flipping frame.(3) positioning component: this component includes a u-shaped plate connected to the side of the baseplate and an abutting mechanism mounted at the top of the u-shaped plate.(4) abutting mechanism: it involves a threaded rod inserted into the top of the u-shaped plate, with a rotating knob fixed at its top and an abutting plate rotating on its bottom.(5) u-shaped plate, slider, and baseplate: the u-shaped plate has a slider fixed on one side, and the baseplate features a side groove suitable for the slider's adaptation. the end face of the slider and the side groove are t-shaped, and a positioning bolt is installed on one side of the slider.(6) wire mechanism: it comprises an extension frame fixed to one side of the baseplate and a wire wheel mounted at the top of the extension frame.(7) buffer component: this component includes a guiding rod inserted into the sliding rail, with a buffer block fixed at one end and a convex block fixed at the other end. the guiding rod has a spring near the buffer block, and the outer wall of the guiding rod forms a damping sliding fit with the sliding rail.(8) marking component: it consists of a marking slot opened on one side of the baseplate near the end of the rotating shaft. a extending shaft, connected to the end of the rotating shaft, is pivotally inserted into the marking slot. a pointer is fixed on one side of the extending shaft, and circular angle markings are provided within the marking slot. [2] 4. implementation method 4.1. device movement principles (1) at one end of the baseplate, a rotating shaft is installed, and a sliding rail is mounted on the rotating shaft. the sliding rail is equipped with an elevating component that adjusts the incline angle of the sliding rail away from the rotating shaft. a positioning component is installed on one side of the baseplate to secure it in place. near the rotating shaft, the sliding rail features wire holes, and a wire mechanism is fixed at the end of the baseplate close to the wire holes. [3] to begin the experiment, the apparatus is placed along the edge of the experimental table, and the positioning component is used to secure the baseplate at the edge of the table, making it convenient for use. then, the dot timer is installed at one end of the sliding rail, and a rope with attached weights is connected to the test car. the test car is connected to the paper tape passing through the dot timer. by releasing the weights, the car moves along the sliding rail, facilitating velocity measurements. the elevating component is used to adjust the sliding rail to different incline angles, obtaining various velocity measurements. the overall device is easy to store and adjust. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (2) the elevating component includes a flipping frame connected to the baseplate for rotational movement. the bottom of the flipping frame is connected to a threaded reciprocating mechanism. the threaded reciprocating mechanism consists of a column fixed within the baseplate, with a threaded rod attached. one end of the threaded rod has a rotating handle, and the other end has a threaded block that fits tightly against the baseplate. the top of the threaded block is connected to the bottom of the flipping frame. by rotating the handle, the threaded rod drives the threaded block to move away from the rotating shaft along the baseplate, causing the flipping frame to lift one end of the sliding rail away from the rotating shaft and achieve the purpose of adjusting the incline angle of the sliding rail. (3) the positioning component includes a u-shaped plate connected to the side of the baseplate and an abutting mechanism mounted at the top of the u-shaped plate. the abutting mechanism comprises a threaded rod inserted into the top of the u-shaped plate, with a rotating knob fixed at its top and an abutting plate rotating on its bottom. the u-shaped plate is fixed with a slider on one side, and the baseplate has a side groove suitable for the slider's adaptation. the end face of the slider and the side groove are t-shaped, and a positioning bolt is installed on one side of the slider. the u-shaped plate can be fitted around the edge of the experimental table. by turning the knob, the threaded rod rotates, and the abutting plate clamps the u-shaped plate against the edge of the table, facilitating the positioning and fixation of the baseplate, thereby preventing the apparatus from shaking during velocity testing. [4] (4) the wire mechanism includes an extension frame fixed to one side of the baseplate, with a wire wheel mounted at the top of the extension frame. the wire wheel guides the testing rope to prevent shaking. figure 1: schematic diagram of the experimental apparatus (5) the buffer component: two symmetric buffer components are set at one end of the sliding rail close to the rotating shaft. the buffer components consist of guiding rods inserted into the sliding rail, with buffer blocks fixed at one end and convex blocks fixed at the other end. the guiding rods have springs near the buffer blocks, and the outer wall of the guiding rods forms a damping sliding fit with the sliding rail. the buffer blocks, together with the guiding rods' damping and the spring's elasticity, perform buffer and braking functions on the car moving mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to the end of the sliding rail, preventing violent collisions and buffering the initial impact of the car. [5-6] see figure 1 below for specific details. the specific components in figure 1 are as follows: 1. baseboard; 2. slide rail; 3.side groove; 4. positioning component; 5. slider; 6.extension frame; 7. wire wheel; 8. wire hole; 9. buffer component; 10. axis 4.2. operation procedure in this study, a physics experimental apparatus for simulating velocity was designed. the apparatus utilizes a u-shaped plate to be fitted around the edge of the experimental table, and by turning the knob, the threaded rod is rotated to clamp the baseplate against the edge of the table, facilitating its positioning and fixation for ease of use. by turning the handle, the threaded rod drives the driving block to move away from the rotating shaft along the baseplate, causing the flipping frame to lift one end of the sliding rail away from the rotating shaft. multiple adjustments of the sliding rail are made to different incline angles, obtaining various velocity measurement data. the extension shaft synchronously rotates with the turning base point of the sliding rail, driving the pointer to rotate synchronously, and aligning with the angle marks in the marking slot to quickly adjust the incline angle of the sliding rail, making the entire device easy to store and adjust. to begin the operation, the apparatus is placed along the edge of the experimental table, with the u-shaped plate positioned at the edge of the table. then, by turning the knob, the threaded rod is rotated to clamp the baseplate against the edge of the table, facilitating its positioning and fixation for ease of use. the dot timer is then installed at one end of the sliding rail, and the rope with attached weights is connected to the test car. the test car is connected to the paper tape passing through the dot timer. by releasing the weights, the test car moves along the sliding rail for velocity measurement. the buffer block is employed to dampen and buffer the initial impact of the car as it reaches the end of the sliding rail, preventing violent collisions. the handle is then turned to drive the threaded rod, causing the driving block to move away from the rotating shaft along the baseplate.[7] the flipping frame lifts one end of the sliding rail away from the rotating shaft. multiple adjustments of the sliding rail to different incline angles are made, obtaining various velocity measurement data. the extension shaft synchronously rotates with the turning base point of the sliding rail, driving the pointer to rotate synchronously. the angle marks in the marking slot are used to quickly adjust the incline angle of the sliding rail. the entire apparatus is easy to store and adjust. 5. conclusion in high school physics teaching, experiments play a crucial role in helping students understand the key features of phenomena and grasp the knowledge taught in textbooks. among various experiments, velocity-related experiments are of great importance. however, the current velocity simulation devices mainly rely on dot timers and sliding tracks. these devices have limitations, such as the inconvenience of adjusting the track angle, which affects the diversity of experimental data. to address these shortcomings, this article proposes a conceptual physics velocity simulation apparatus. it involves using a u-shaped plate to fit around the edge of the experimental table, and with the aid of corresponding knobs, the threaded rod can be rotated to easily position and fix the baseplate. this setup allows for multiple mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 4; july august 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset adjustments of the sliding rail to different incline angles, thereby obtaining diverse velocity measurement data. the apparatus has the advantages of easy storage and adjustability, effectively addressing the current deficiencies in physics velocity experiment devices. the goal is to contribute to efficient and exciting physics classroom experiences. references lin, t., song, h., sun, y., et al. (2021). development of high-temperature and high-pressure visualization physics simulation apparatus. laboratory research and exploration, 40(07), 76-79. [2] chen, s. s. (2021). improvement and application of the "measurement of reaction rate" experimental apparatus. high school biology teaching, (19), 61-63. hong, h. b., song, l. y., feng, y. q., et al. (2021). development of high school physics experimental apparatus based on stem concept. chinese physics bulletin, (06), 93-96. zang, z. y., jing, x. b., long, q. h., et al. (2018). exploration of mechanical design for physics experimental apparatus. china new technology and new products, (18), 92-93. wang, x. q., dai, l. n. (2015). truly optimizing physics experiments: achieving efficient physics classroom through the improvement of newton's second law experiment apparatus. reference for high school physics teaching, 44(23), 58-59. yang, l., ren, x. h., qi, y. g., et al. (2010). design and application of multi-functional structural physics simulation apparatus. journal of china university of petroleum (edition of natural science), 34(05), 152-158. zhang, x. k. (2008). analysis of high school physics experimental apparatus and experimental methods selection. curriculum, textbooks, and teaching research (education research edition), (05), 44-45. mailto:topacademicjournals@gmail.com article ludovia (de 22 000 à 30000 caractères espaces compris) academic journal of science, engineering and technology vol.1, issue 1; march -2023; https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 6| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset optimizing the rear-disconnected steering trapezoid for fsae racing cars hanqi wang, bo wu, xiaolong cheng & yongjun mao school of mechanical & power engineering, harbin university of science and technology, harbin 150006, china abstract the steering system of fsae racing car plays a vital role in maintaining the direction and stability of the car. the design of the steering trapezoid is an important component of the steering system, and the postdisconnected steering trapezoid has been analyzed and optimized in this study. to improve the steering behavior of the car, a mathematical model of the post-disconnected steering trapezoid was developed. the objective function was established using the modified ideal ackerman steering formula, and the geometric relationship between the actual inner and outer corners. additionally, a constraint equation was established to ensure operational convenience of the steering mechanism. matlab was used to find the design variable parameters that satisfied the fatigue strength while ensuring that the actual internal and external angle relationship was maximally close to the ideal ackerman steering. furthermore, the dynamic change of the toe angle of the parallel two-wheeled beating was simulated using adams, to ensure that the car met the stability requirement. the results showed that the optimized post-disconnected steering trapezoid can significantly improve the steering behavior of the fsae racing car. the mathematical model and optimization method developed in this study can provide a theoretical reference for the design of the steering trapezoid in future studies. moreover, this study highlights the importance of considering the fatigue strength and dynamic simulation in the design process of the steering system for fsae racing cars. overall, the optimized post-disconnected steering trapezoid design can improve the stability and steering performance of fsae racing cars, providing better handling during dynamic competition. the proposed method can be applied to the design and optimization of steering systems in various racing cars, making it a valuable contribution to the field of motorsport engineering. keywords: fsae racing car, steering system, steering trapezoid, post-disconnected, ideal ackerman steering, mathematical model, fatigue strength, dynamic simulation, stability requirement. introduction among the components of the fsae, the steering system is directly related to the passing and steering stability of the car. the steering system of the fsae racing car is the mechanism which is used to maintain or change the direction of the car. and it also can ensure a coordinated corner relationship between the steering wheels when the car is turning [1]. in the dynamic competition, the 8-word loop, high-speed obstacle avoidance and endurance race have higher requirements on the stability of the steering system, and the design of the steering trapezoid is a particularly important part of the steering system design [2]. so, a reasonable design of steering trapezoid not only improves the steering ability of the car, but also improves the overall performance of the car to a certain extent, which is of great significance for improving the performance of the car. presently, scholars at home and abroad have deeply analyzed and researched on the structural design of the fsae racing car to the trapezoid from various angles. for example, song xueqian and others established a mathematical model of the front-disconnected steering trapezoidal structure and collected data through an angular displacement sensor to correct the steering angle mailto:topacademicjournals@gmail.com hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 7| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [3]. shaofei and others realized the design of parallel ackerman geometry steering trapezoid [4]. and zhangkai and others proposed a steering trapezoidal joint optimization design method and improved the speed and corner stability of the fsae racing car [5]. the above research provides different research methods for the steering trapezoid of the car, but the front layout is adopted in the layout of the steering trapezoid, and the research results are not fully applicable to the layout scheme adopted in this paper. so, in this paper we further analyzed and optimized the rear-disconnected steering trapezoid with the steering gear located behind the front axle. methodology steering trapezoid scheme selection in the rules issued by the competition, it is clearly stated that the use of steer-bywire steering and electronically controlled steering is prohibited. considering the light weight of the fsae racing car, most of the teams use unassisted mechanical rack and pinion steering gears, which have simple structure, small size, easy to make, etc., can reliably meet the steering task [6]. because of the compact layout of the fsae racing car, in order to ensure good compatibility between the steering system and the independent suspension system, the disconnected steering trapezoid is often used. according to the different positions of the steering trapezoid and the rack and pinion steering gear with respect to the front axle, the arrangement can be divided into four types [1]. and the rear trapezoidal arrangement of the steering gear behind the front axle is simple. so, in this paper we use the rear-disconnected steering trapezoidal powerless mechanical rack and pinion steering gear with the steering gear behind the front axle. we analyze and design the fsae racing car. and its structural diagram is shown in figure 1. figure. 1 rear-displacement steering trapezoidal structure intention of the steering gear behind the front axle establishment and analysis of steering trapezoidal mechanism model when the car is turning, in order to ensure that its four wheels are all rolling around the same instantaneous center point without sliding, that is, to meet the ackerman steering [7], the angle of the inner and outer wheels of the front axle should satisfy the relationship as shown in figure 2. hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 8| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 2 ideal ackerman corner according to the geometric relationship, the concrete expression of the ideal inner and outer wheel angles when meeting ackerman steering can be obtained: cotβ0 −cotα0 = k l/ (1) where α0 is the ideal inner wheel steering angle, β0 is the ideal outer wheel steering angle, k is the main pin center distance, and l is the wheelbase. if the self-variation angle is assumed to be the ideal inner wheel steering angleα0 , then the angle of change is the ideal outer wheel steering angleβ0 , the expectation of the variable angle β0 can be expressed as: β0 = arccotcot( α0 −k l/ ) (2) however, in the actual car steering process, the tire will be subjected to the centrifugal force generated during the curve driving, that is, the cornering force. under the action of the cornering force, the tire will have a certain deformation, so that the actual inner and outer wheel angles are smaller than the ideal inner and outer wheel angles. so, it is necessary to correct the ideal inner and outer wheel angles [5]. thus, the ackerman steering correction coefficient ε is introduced to correct the ideal outer wheel steering angle β0 . and the specific relationship between the corrected outer wheel steering angle β * and the ideal outer wheel steering angle β0is : ε= β α* −0 ×100% (3) β α0 −0 then, putting formula (3) into formula (2), we can obtain the expected value of the corrected ideal outer wheel steering angle β * as follow. β ε * = × arccot cot α0 − kl −α α0 + 0 (4) place the selected steering gear on the rear trapezoidal broken rack and pinion steering trapezoid behind the front axle. and after simplification, the mathematical model can be obtained, as shown in figure 3. figure. 3 rear disconnected steering trapezoidal model when steering, the steering gear drives the gear rack to move. and under the action of the tie rod, the inner and outer steering wheels will rotate to generate the steering angle [3]. during the steering process, the tie rod and the knuckle arm are hinged, and only the relative position change occurs between them, and the length of each rod is not change. therefore, according to the geometric relationship between the tie rod and the knuckle arm, we can obtain the relative relationship between the various parameters of the steering ladder structure, which is as follows: before turning, the distance l2 from the break point to the midpoint of the ball joint pin end of the knuckle arm is: l2 = k −2m −l1 ×cosϕ 2 +(l1 ×sinϕ−h ) 2 (5) where l1 is the arm length of the trapezoidal arm that turns to the trapezoidal structure, ϕ is the bottom angle of the steering trapezoid, h is the horizontal distance from the center line of the rack to the center point of the kingpin, and m is the length of the tie rod. when turning, the movement stroke s of one side of the rack is: hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 9| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset s =− l2 2 l1 ×sin(ϕ β+ 0 )−h 2 −l1 ×cos(ϕ β+ 0 )+ k −2m (6) when the car is turning, the actual outer wheel steering angle β1 is: 2 l12 + h 2 + k −m β1 = arctan k −2hms + arccos 2× ×l1h 2 + 2k −2−ms −s− l2 22 −ϕ (7) − the actual outer wheel steering angle β1 should be designed as close as possible to the expected value of the corrected outer wheel steering angle β * . when the design value is closer to the expected value of the theoretical value, the car can be closer to the ideal ackerman steering during the actual steering process. in order to objectively evaluate the closeness between the actual outer wheel steering angle β1and the expected value of the corrected ideal outer wheel steering angle β * , we introduce an objective function f x( ) for evaluating the advantages and disadvantages of the steering trapezoid design. the specific expression is as follows: where µ is the correction factor, x is the design variable and x =[m h ϕl1] t . considering that fsae racing cars are always driven under high-speed conditions, the wear pattern of the tire surface pattern is more serious. when evaluating the design of the steering trapezoid, it is necessary to take into account the influence of tire wear on it. thus, the introduction of the correction coefficient µ makes the objective function f x( ) of the evaluation steering ladder design closer to the actual situation. when setting constraints, we focus on the ease of operation of the steering mechanism. because of the low quality of the fsae racing car and the limitation of the installation space, the fsae racing car generally does not use the steering assist device, which requires the entire steering mechanism to be maneuverable during handling. while in the steering trapezoidal mechanism, the direct influence of the handling of the portability are the length of the tie rod m and the bottom angle ϕ of the steering trapezoid. when the values of the design variables m and ϕ are selected too small, the steering load applied to the tie rods is too large, which is inconvenient for the racer to turn [1]. when the length m of the design variable tie rod is too large, the size of the entire steering trapezoid will increase, which will not only increase the difficulty of the fsae racing steering mechanism, but also cause serious problems with the interference of the front suspension. thus, selecting the length m of the appropriate tie rod and the bottom angle ϕ of the steering trapezoid have important significance for the manipulation and arrangement of the entire steering mechanism. the specific constraints are as follows: m −mmin≥ 0 mmax−m ≥ 0 (9) ϕϕ−min ≥ 0 in the formula, mmin is the general design minimum of the tie rod, mmax is the general design maximum of the tie rod, and ϕmin is the general design minimum of the base angle of the steering trapezoid. according to the design experience, the general design minimum value of the tie rod is mmin= 0.11k , the general design maximum value of the tie rod is mmax= 0.15k , and the general design minimum value of the bottom angle of the steering trapezoid is ϕmin= 70 . at the same time, the entire steering mechanism should also have high transmission efficiency when maneuvering. the steering trapezoidal mechanism is essentially a multi-link mechanism. in the multi-link mechanism, the transmission angle can effectively reflect the transmission quality of the linkage mechanism. thus, the steering angle is further constrained by the transmission angle. in the motion diagram of the steering ( ) 2 2 2 2 2 1 2 2 1 0 0 0 2 arctan arccos 2 2 2 % 1100 cot cot k m l h s l h k m m k s l s h fx k arc l ϕ µ ε α α α − + + − − − + − − − − + × × = × − × × − − + (8) hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 10| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mechanism designed above, the transmission angle is γ (as shown in figure 3). and the larger the transmission angle γ, the better the work of turning the trapezoidal mechanism. during the steering process, the transmission angle x is constantly changing with the steering angle. in order to ensure the good transmission performance of the steering mechanism [8], the minimum transmission angle of the steering mechanism should be γmin≥ 40 . considering that the fsae racing car needs to meet the characteristics of high-speed continuous passage of multiple corners during the competition, the minimum value of the transmission angle of the steering mechanism is put forward here, that is, the minimum transmission angle of the steering mechanism should satisfy γmin≥ 50 . during the steering of the car (take the turn to the left as an example), when the car reaches the extreme position of the left steering, the relationship between the minimum turning radius dmin and the maximum value βmax of the steering angle of the front outer wheel can be obtained. the specific geometric relationship is as follows: βmax = arcsindminl / 2−a (10) in the formula, a is the main pin offset. through the study of the fsae track, the minimum turning radius dmin= 3m can be found, so the maximum value βmax of the front outer wheel steering angle can be determined. through the geometric relationship, it can be found that the current steering angle of the steering wheel reaches the minimum value γmin when the maximum value of the steering angle of the outer wheel is reached, so the constraint equation for the minimum value γmin of the transmission angle can be obtained. the specific expression is as follows: 2 γmin= arccosl +l − 2k× ×− 2l1ml2−s −h 2 ≥ 50 (11) according to the above analysis, the solution of the steering trapezoidal mechanism is essentially a constrained nonlinear programming problem. under the constraints of the constraint equations (9) and (11), matlab is used to solve the minimum value of the objective function f x( ), which evaluates the advantages and disadvantages of the steering trapezoid design. then we can get the best value of the design variable x . after determining the optimal value of the design variables, the design parameters of the steering gear in the steering structure can be initially selected. in the rack and pinion steering gear, the movement stroke s on one side of the rack and the maximum angle wmax on one side of the steering wheel have the following relationship: 360×wmax (12) s = π× ×m z in the formula, m is the modulus of the steering gear, and z is the number of teeth of the steering gear. the modulus m of the steering gear should not be too small. if it is too small, the meshing point of the rack will be too close to the top of the tooth when meshing, causing the bending stress of the root to be too large, which is prone to chipping. thus, the modulus m of the steering gear is generally 2-3mm [7]. in the selection of the number of teeth z of the steering gear, considering that the diameter of the indexing circle is small, if the number of teeth is too large, there will be a problem of difficulty in processing and low degree of coincidence of gear meshing transmission, and attention should be paid to avoiding the cutting phenomenon. thus, the number of teeth z of the steering gear is generally selected from 8 to 19. the maximum corner wmax of the steering wheel on one side generally requires no more than 10 from the middle to the left or to the right. thus, putting the optimal design variables into the formulas (6) and (12), and according to the above specific requirements for the rack and pinion mechanism parameters, the modulus m of the steering gear and the number of teeth z of the steering gear can be preliminary determined. then, through checking the tooth surface contact fatigue strength of the gear, we can determine the gear parameters that meet the strength conditions. the specific process of the steering trapezoidal mechanism optimization design is shown in figure 4. hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 11| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 4 steering trapezoid optimization design flow chart results and discussion steering trapezoid optimization design according to the rules of the fsae [6] and the design experience of the fsae racing car, the initial values of the design variables and the upper and lower boundary conditions are determined as shown in table 1. table 1 initial value of design variables and upper and lower boundary conditions design variable initial value upper and lower boundary conditions length of tie rod m / mm 190mm 160mm220mm the horizontal distance from the centerline of the rack to the center point of the kingpin h /mm 35mm 30mm-40mm corner of the steering trapezoid ϕ/ 75 60 90 − arm length of trapezoidal arm 75mm 50mm-100mm hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 12| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset according to the above analysis of the steering trapezoidal mechanism model, using the fmincon function in the mtalab optimization toolbox, formula (8) is used as the objective function of the solution, and equations (9) and (11) are used as the constraint equations, and table 1 is used as the upper and lower boundary conditions of the design variables. and the optimized design results are shown in table 2. table 2 steering mechanism technical parameter table design variable design value length of tie rod m / mm 200mm the horizontal distance from the centerline of the rack to the center point of the kingpin h /mm 39mm corner of the steering trapezoid ϕ/ 79 arm length of trapezoidal arm l1 / mm 70mm rack travel on one side s /mm 44mm modulus of the steering gear m/ mm 2mm number of teeth of the steering gear z / teeth 13 teeth in order to test the optimization effect of the steering trapezoid design, the relationship between the input angle of the outer steering wheel and the output angle of the inner steering wheel is drawn by matlab, as shown in figure 5. when the angle curve of the actual inner and outer wheels is closer to the angle curve of the ideal ackerman inner and outer wheels, it shows that the closer the fsae car is to the ideal ackerman steering when it is actually turning. it means that the smaller the difference between the two curves is, the better the actual steering effect is. from figure 5, it can be seen that after adopting the optimized design scheme of this paper, the actual corner curve is closer to the ideal corner curve than the initial corner curve. thus, the design of the steering trapezoid in this paper can better match the ideal ackerman steering relationship under the condition of meeting the design requirements and has better steering performance. the parameter design of the steering mechanism not only affects the steering performance of the car, but also affects the steering stability of the car to some extent. during the steering of the fsae, the relative motion of the steering mechanism and the suspension mechanism changes the toe angle of the wheel. while the size of the toe angle indirectly affects the wear level of the fsae racing tires. thus, in the design process of the steering mechanism, the degree of change of the toe angle during the running of the wheel should be minimized, so that the car maintains good steering stability during the steering process. hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 13| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure.5 inner and outer wheel angle relationship curve the minimum value of the toe angle change during parallel double-wheel bounce is optimized using the insight module in adams. the optimization result is shown in figure 6. according to figure 6, it can be seen that the toe angle of the wheel before and after optimization is reduced from 1.7957° to 1.4478°. after adopting the design of the steering mechanism of this paper, the degree of change of the toe angle when the wheel is beating can be effectively reduced. thus, from the perspective of dynamics, the optimized design of this paper makes the fsae racing car have higher steering stability when steering and achieves the expected optimization results. figure.6 simulation curve of parallel double wheel bounce toe angle change conclusion in this paper, we analyze and model the rear-disconnected steering trapezoid of fsae racing car and transform the steering trapezoidal multi-link mechanism into a mathematical model. and we modify the ideal ackerman steering formula and consider the effect of the cornering force on the ideal ackerman steering. the objective function is established by the geometric relationship between the modified ideal ackerman steering formula and the actual inner and outer corners, and the operation convenience of the steering mechanism is constrained. after adopting the idea of nonlinear programming, and then determining the upper and lower boundary conditions of the design variables, the initial values of the design variables are continuously changed by matlab software, so that the final design structure can maximally close to the actual internal and external rotation angles under the condition of satisfying the fatigue strength. the adams software is used to simulate the dynamic change of the toe angle of the parallel two-wheeled. it is verified that the steering trapezoidal design given in this paper not only has good steering performance, but also improves the steering stability of the car to a certain extent. and it also improves the dynamic performance of the fsae racing car while driving in a corner. the results of the study provide a certain reference value for the design of the fsae racing steering mechanism. acknowledgement this paper is supported by the harbin university of science and technology college students' innovation and entrepreneurship training program (project no. 201810214162). references [1]. jilin university, wang wangyu. automotive design [m]. the third edition. beijing: china machine press, 2016. [2]. zhang xiangbo, he yaohua. optimization and simulation of trapezoid steering of rear wheel of fsae [j]. automation & instrumentation, 2017(12):48-54. hanqi wang, bo wu*, xiaolong cheng, yongjun mao optimizing the rear-disconnected steering trapezoid for fsae racing cars 14| a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [3]. song xueqian, zhou yuebin, huang cheng. analysis and optimization of fsae racing steering structure parameters [j]. equipment manufacturing technology, 2018(07):73-75+87. [4]. shao fei, li chuanchang, xu huayuan. design and optimization of fsae racing car steering trapezoid [j]. journal of shanghai university of engineering and technology, 2018(1). [5]. zhang kai, chen pan. joint optimization design of fsae racing car steering trapezoid [j]. shaanxi auto, 2015(4):72-74. [6]. organizing committee of rules of china formula university car race. 2018 chinese formula student car competition entry manual [r]. beijing: saec, 2018. [7]. beijing institute of technology, wang jian. formula university racing design [m]. the first edition. beijing: beijing institute of technology press, 2016. [8]. southeast university mechanical engineering group, zheng wenwei. principle of mechanics [m]. the seventh edition. beijing: higher education press, 1997. academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset enhancing agricultural practices: the impact of local radio programs on small-scale farm extension dr. ayesha malik university of sargodha, pakistan abstract: the agricultural sector in pakistan, a crucial component of the country's economy, faces challenges in terms of slow growth, largely attributed to the limited adoption of modern technology and weather-related issues. despite its significance, the growth rate of agriculture in pakistan has been sluggish, with the sector contributing 21.4% to the gdp and employing 42.1% of the labor force. in 2013, the growth rate in agriculture was 3.3%, down from 3.5% in the previous year, as reported in the economic survey for 2012-2013. this underperformance in agriculture, especially when compared to other countries, is primarily due to yields falling short of their attainable potential. to address this issue and boost agricultural productivity, farmers need to embrace new methods and technologies on their farms. the adoption of these innovations is crucial for increasing actual output and improving the overall performance of the sector. in this context, mass media plays a pivotal role in educating and informing farmers through various programs and channels, including television, newspapers, and radio. agricultural extension workers have traditionally played a significant role in disseminating valuable information to small-scale farmers. however, mass media platforms offer distinct advantages due to their extensive reach and wide coverage. mass media platforms serve as catalysts by introducing farmers to new information, prompting them to seek more detailed insights from peers, extension workers, and friends. keywords: pakistan agriculture, agricultural growth, modern technology, mass media, agricultural extension, productivity. introduction pakistan is an agriculture country as it is a largest sector of our economy. agriculture contributes to 21.4 % to gdp and employs 42.1 % of labor force. the growth of agriculture remained slow due to non adoption of modern technology and weather conditions. the growth of agriculture in 2013 accounted at 3.3 % while in previous year it stood at 3.5 & (economic survey, 2012-2013). in spite, the importance of agriculture sector the growth of this sector remains slow. when compared to other countries the growth of agriculture in pakistan remains slow (khan, 2002). the actual yield is lower than the attainable yield from farms is the basic reason behind this slow rate. so, it is the basic need of farmers to adopt new method and technologies in their farms to increase actual output. in this context, media plays a vital role to educate farmers through their programs. (mohy-ud-din, 2011) states that agricultural extension workers play a prominent role in small scale farm extensions through providing useful information to farmers. but the mass media such as tv, news papers and radio has its own importance. mass media hold a high position as compared to extension workers due to their wide coverage. mass media stimulate farmers about new information and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset then farmers got to their peer, extension workers and friends to get more detailed information (behrens, 1984). the cost of educating farmers through mass media is low as compared to extension workers (oakley, 1985) but the on time feedback cannot be generated through mass media (muhammad, 2005). in mass media mechanisms tv, news papers, research publications and radio plays a vital role in disseminating agricultural information (muhammad, 2006). but radio is a more power full instrument for liberation of fast information due to its vast coverage in local areas. in pakistan, there is monopoly of radio since 2002 but the govt of musharaf took step to reduce the monopoly and through pemra issues license to private radio known as fm or local radio. this led to 40 fm radio emergences in early but now the figure is in thousands. (abbas et al., 2003), states that in central punjab most of farmers are exposed through radio and television. radio is proved as a strapping tool for dissemination of agricultural information chapman et al., 2003: nakabugu, 2001). in pakistan local radio are dominating in rural areas and seen as a tool information exchange. this study aim is to examine local radio agricultural programs in term of farm extensions. the study also provides a deep insight about which mass media is preferably accepted by the farmers. the study also examines the characteristics of small farmers in term of land ownership. the main objective of the study is to explore the study statement “more farmers listen, more they adopt” literature review pakistan is an agro based economic country. pakistan has geographical area of 79.61 million out of this 22.17 % is cultivated which is 39 % of the total area. almost 65 % of population lives in rural areas. agriculture sector contributed 53 % to gdp and its share of export earning is 57 % (ministry of finance, pakistan). pakistan agriculture sector growth rate is declining from recent few decades. farmers need market information to improve their farm production. dissemination of information to farmers can increase the output of their farms. proper market information is the basic need of farmers because it enables farmers to make relevant and accurate decisions (ozowa 1995 & leroux et.al, 2001). market information enables the farmers to make decision regarding what to produce, how to produce and whether to store the products or not (fao, 2005). radio is a strong tool in disseminating the agricultural information. in developing countries market information initiative are the part of agriculture and agro business strategies that government paid attention ( haerah et.al, 1979 & lutz, 2006). in developing countries radio act as a basic tool for communicating in rural area population (foa, 2001). (hussain, 1997) states that radio and tv are the most effective tool of communication. the study of (wedell, 1986) reveals that radio is a dominating tool for change in culture, development, health issues, and for better agricultural development. a study conducted by atkin (1987) in canada explore that more than 100 million villagers listen farm based local network radio. rein (1988) states that regional radio programs are favourite among people. the study result of (kelsey and hearne, 1955) states that the villagers who don’t participate in social meetings and rarely use technology meet their informative needs through radio. the study results of (arokoyo, 2003) conducted in nigeria proved that video, tv and radio are the major sources of farmers to get information. information sources for farmers are tv, radio, publications, practical education, news papers, agriculture exhibitions and extension workers (ekoja, 2003). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset radio agricultural programs are timely and can extend message to target audience irrespective of location, socio economic issue, topography and distance (omenesa, 1994). radio programs has been used for dissemination of agricultural information for better farmers performance (enitan, 1988) both in developed and under developed countries. small scale farm extension farm extension means to enlarge the new innovations in the ground of agriculture by the farmers. for improvement in agriculture sector agriculture extension services should be provided to farmers (mohy-uddin, 2011). traditionally, agriculture extension is undertaken through extension workers. ozowa (1995) conducted a study in nigeria and states that agriculture marketing information is provided by ministry of agriculture through extension workers and broad cast media. the study outcomes of (rasak, 2012) disclose that radio agriculture broadcasting is effective for farmers and must be undertaken on long duration for agricultural extension. in pakistan, most of the farmers are small because they hold a few hectares. table no.1 farm ownership in pakistan size of farms (hectares) farms cultivated area % no “000” % area “000” hectares all farms 6620 nil 20438 nil got farms less than 500 nil 31 nil private farms 6620 100 20470 100 under 0.5 1290 19 363 2 0.51-1 1099 17 821 5 1-2 1425 22 1981 11 2-3 966 15 2257 12 3-5 891 13 3443 18 5-10 580 9 3891 20 10-20 261 4 3324 16 20-40 78 1 1955 8 40-60 15 less than 0.5 689 3 more than 60 14 less than 0.5 1683 5 source: govt of pakistan (2005), federal bureau of statistic, islamabad the report of federal bureau of statistic of pakistan (2005) defines the ownership of farms in pakistan (see table no.1). according to this table pakistan has estimated 6620 farms. the 86% farms are less than 5 hectares and 95% are less than 10 hectares. it means small scale farmers are dominating in our country and most of the yield is produced by small farmers. because most of the farmers are small land holders that’s why study is conducted on small farmers. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset methodology a quantitative approach is adopted to check the role of local radio agricultural programs on small scale farm extensions. (haider, 2014) states that quantitative approach is quantifiable, apparent and be able to manipulate. a survey is conducted on farmers of district layyah who hold less than 10 hectares land. survey is used because it is provide the main idea about the research topic and based on questionnaire which is provided to respondents to show their answers (malhotra, 2006 & haider, 2014). a set of 170 questionnaires was scattered between small farmers of district layyah and only 150 questionnaires were collected confidentially. convenient sampling method is used to overcome the cost and time constraints. analysis of data collected through well designed questionnaires is done through spss (20). findings the population of this study comprises of 150 small farmers from district layyah. the finding of the study reveals that tv and radio is the most dominating tool for dissemination of agriculture information’s. from table no.2, it is observed that radio is the most accepted in rural area as (94.7 %) are listening radio agricultural programs. on the other hand tv also emerges as a strong tool because (85%) farmers are watching agricultural programs. it is also observed that 56.7 % farmers also get information from other farmers. in district layyah only 14 % farmers get information from research publications. (see table no.2). table no.2 which media do you like more for getting agricultural information very much little cumulati much ve percent publications 21 14.0 14.0 14.0 farmers 64 28.7 28.7 56.7 tv 43 28.7 28.3 85 radio 42 15.3 9.7 94.7 extensionsts 8 5.3 5.3 100.0 total 150 100.0 100.0 farmer’s of district layyah are more exposed by radio agricultural programs. in table no.3 percentage distribution if study items is shown. from table np.3, results appears as sa (strongly agree) and a (agree) as more preferable options for farmers. table no.3: key items used to check role of local radio agricultural campaigns items sd d n a sa i frequently listen radio agriculture programs. 11.8 14.1 4.97 38.1 31.03 i pay full attention to listen radio agriculture 14.3 7.7 10.6 30.1 37.3 programs. i usually listen radio to get agriculture programs. 5.4 10.7 2.1 27.1 54.7 i get more information about agriculture innovation 3.2 10.4 9.0 33.1 44.3 from radio. radio agriculture programs help me to adopt new 5.6 13.4 8.5 42.1 30.4 information. i get information about new seed varieties from radio 6.2 9.4 11.2 23.1 50.1 campaigns mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset i get information about new harvesting methods 11.5 13.4 9.3 29.1 36.7 from radio campaigns i get information about new pesticide varieties from radio campaigns i get information about new lazer technologies from radio campaigns i practice new methods of farming in my farms by listening radio agriculture programs. radio is best media for acquiring agricultural information’s. radio agricultural campaigns motivates me regarding adoption radio help me in making decisions about adopting new innovation radio affect my agricultural purchasing i adopt new farm technologies after listening radio agriculture campaigns radio agricultural campaigns help me in purchasing new varieties of pesticides radio programs provides me help to adopt new agricultural innovations 3.1 8.4 7.9 43.1 37.5 5.4 11.4 2.3 33.1 47.8 2.4 11.2 8.5 38.4 39.5 3.7 9.4 7.0 21.5 58.4 3.9 5.4 13.0 40.1 37.6 4.2 9.8 7.4 42.5 36.1 7.0 13.4 12.1 22.2 45.3 8.9 13.4 8.0 11.6 58.1 10 13.4 9.3 38.3 29.0 7.2 8.6 10.4 32.7 41.1 this is in common show that farmers are accepting radio agriculture programs on a preferable way. in most cases, this table shows that radio agriculture programs have significant impact on farm extensions of small farmers of district layyah. discussion the study discussion reaffirms the study statement “more farmers listen, more they adopt”, discuss the role of local radio agricultural programs on the small scale farm extensions and also include resolved remarks of the researcher. the findings of the study reveal that most of the farmers listen agricultural programs on the radio to get new information’s (see table no.2). the study also explore that most of the farmers in pakistan hold small land ownership. majority of farmers in pakistan hold less than 10 hectares of land (see table no.1). they study results also provide a deep look on how local radio agricultural programs play a role to adopt new technology by the farmers of district layyah. the study explore that most of the farmers listen radio agriculture programs because it provide them new information about agriculture. farmers of the district layyah adopt new technology, new varieties of seeds because of radio programs. findings of the study also prove that local radio helps farmers to adopt new information about agriculture and hence plays a vital role in exercising new methods and technologies in farms. it is also explore that farmers of district layyah adopt new farm practices through agricultural campaigns of local radio. (see table no. 3). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset local radio helps farmers in their purchasing of agricultural commodities. the study results are in favor of the study statement “more farmers listen, more they adopt”. local radio has a significant role in small scale farm extension as farmers adopt new technologies and farm practices through this medium. the study findings explore that local radio plays a vital role in small scale farm extensions. limitations & future direction this study is undertaken on the farmers of district, layyah. the results are not widely generalizable. the study focus is only local radio but the tv and other media also has its own importance. it is recommended that future research must be undertaken by taking into account other mass media tools and with wide sample. there must be a study on the role of extension workers in future. references arokoyo, t. (2003). ict for agriculture extension transformation. proceeding of ict’s –transforming agriculture extension? cta’s observatory on icts. sixth consultative expert meeting. wageningen, 23 – 25 september. atkin, g.1987. developing countries farm radio network towards solving the world foodproblem. world farming time, usa. 2(11):20-23 abbas, m., a.d. sheikh, s. muhammad and m. ashfaq, 2003b. role of electronic media in the adoption of agricultural technologies by farmers in the central punjabpakistan. int. j. agri. biol., 5: 22–5 agriculture in pakistan, (2005): ministry defence of pakistan behrens, j.h. and j.f. evans, 1984. using mass media for extension teaching. in: swanson, b.e. (ed.), agricultural extension: a reference manual, pp. 144-155. fao, rome, italy chapman, r., blench, r., kranjac-berisavljevic’, g. and zakariah, a.b.t. (2003). rural radio in a agriculture extension: the example of vernacular radio programs on soil and water conservation in n.ghana. agricultural research and extension network(agren). network paper no. 127. ekoja, i. (2003). farmer’s access to agricultural information in nigeria. bulletin of the american society for information science and technology, 29(6): 2123. enitan o (1988). comparative analysis of radio and television drama. unpublished bsc thesis. university of ibadan. ibadan, nigeria. 215p. fao. (2001). knowledge and information for food security in africa from traditional media to the internet. communication for development group, sustainable development department. rome: fao. fao. (2005). knowledge and information for food security in africa from traditional media to the internet. communication for development group, sustainable development department. rome: fao. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset government of pakistan. 2013. economic survey of pakistan, 2012-2013. government of pakistan. 2005. pakistan statistical year book 2005. statistic division, federal bureau of statistics, islamabad. haider, i., (2014). impact of publicity and sponsorship on customer based brand equity: international journal of science and research, 1(7). p.545 -555. hussain, m., 1997. mass media. in: memon, r.a. and e. basir (eds.), extension methods. pp: 208–61. national book foundation, islamabad–pakistan. haerah a, gani r, schubert b, zehrfield eh (1979). manual of operations for an agricultural market information service, indonesian german technical cooperation project ata 85/86 publication no. 7. khan, s.r.a., 2002. agriculture of pakistan: challenges and remedies.the environ publication, lahore kelsey, d.l. and hearne, c.c. (1955). cooperative extension work. ithaca, new york:comstock pub. associates. lutz c (2006). maize market liberalisation in benin: a case of hysteresis. j. afr. econ., 16(1): 102 – 133. leroux n, wortman ms, mathias ed (2001). dominant factors impacting the development of businessto-business (b2b) e-commerce in agriculture. int. food agribus. manage. rev., 4(2): 205 – 218. mohy-ud-din & badar. h, (2011): marketing of agricultural products in pakistan: theory and practice. p 83-85. muhammad, s., i. ashraf and b.n. siddiqui, 2002. effectiveness of different communication methods/media used by novartis pesticide company in tehsil arifwala. int. j. agri. biol., 4: 335–7 muhammad, s., 2005. agricultural extension: strategies and skills. unitech communications, faisalabad– pakistan makanjuola ss (2002). analysis of reportage of agricultural news and advertisements in the pioneer newspaper (2001 ad). thesis submitted to the department of agriculture economics and extension. university of uyo, nigeria. p. 115. muhammad, s. irfan. m, khan, a.g, asif, m (2006): role of mass media in the dissemination of agricultural technologies among farmers: international journal of agriculture &biology, p417-419. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 5; september october 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset malhotra, n.k., & peterson, m. (2006). basic marketing research: a decision making approach. (2nd ed.). upper saddle river: pearson education inc. nakabugu, s, b. (2001). the role of rural radio in agricultural and rural development translating agricultural research information into messages for farm audiences. programme of the workshop in uganda, 19 february 2001. omenesa z (1994). the role of media in agricultural extension communication. a paper delivered at the training of media officers in research institutes. abu zaria march, 1994. p. 5. olajide b. rasak1 & amusat a. s.2, (2012): perceived efficacy of radio agricultural commodities trend programme among farmers in oyo state, nigeria; journal of media and communication studies vol. 4(3), pp. 46-51. oakley, p. and c. garforth, 1985. guide to extension training. fao, rome italy wedell, g. 1986. making broadcast useful: the african experiencethe development of radio and television in africa in 1980s. manchester, uk: 306. mailto:topacademicjournals@gmail.com beginning at a very young age, today’s students are schooled at home (and just about everywhere else) by television academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the practical and theoretical implications of the limits of evolutionary explanation mary elizabeth jones and susan catherine brown department of biology, hampden-sydney college, hampden-sydney, va 23943 usa abstract: the explanatory power of evolution is a topic of debate among scientists and philosophers. some argue that evolution is a universal acid that can explain all aspects of the natural world, while others believe that there are limits to its explanatory scope. this paper explores the arguments for and against the limitless explanatory power of evolution, and discusses the implications of these arguments for our understanding of the natural world. keywords: evolution, explanatory power, universal acid, noma, limits of explanation introduction: are evolution’s explanatory powers limitless or limited? according to philosopher daniel dennett (1995, 63), evolution is not only true but universal: the central organizing principle explaining all aspects of the living world. dennett likens darwinian theory to an uncontainable ‗universal acid.‘ evolutionary explanations, he declares, corrode every philosophical worldview they touch. people scramble (yet fail, in dennett‘s estimation) to keep darwin‘s dangerous idea at bay by constantly erecting new barriers while old ones are burnt through, as ―new waves of darwinian thinking‖ relentlessly erode temporary ―forces of containment.‖ as dennett states (1995, 63), ―darwin‘s idea had been born as an answer to questions in biology, but it threatened to leak out, offering answers—welcome or not—to questions in cosmology and psychology… if mindless evolution could account for the breathtakingly clever artifacts of the biosphere, how could the products of our own ‗real‘minds be exempt from an evolutionary explanation?‖ yet as dennett trumpets the extraordinary power of evolutionary explanations, he reminds us of stephen jay gould‘s ‗nonoverlapping magisteria‘ or noma essay (1997, 21), which argues that evolutionary explanations must be strictly contained. contra dennett, gould claims that although evolution may be accepted as factual, firm boundaries must be respected. modern science offers evolution as the bedrock foundation underlying all features of living systems. evolutionary explanations (hereafter abbreviated ees) are presented as logical, mechanistic accounts that help us to understand why the natural world is the way it is. but are ees limited in explanatory scope and power? even those who otherwise willingly accept modern science sometimes balk at the sheer audacity of evolutionists to explain every facet of nature, particularly human nature, in evolutionary terms. social scientists occasionally mock ees by affirming that, like any explanation that purportedly explains everything, they are effectively useless (dupré 2001, 74). there is nothing, they tease—no aspect of human behavior, even—that cannot be subsumed within and ultimately explained by evolution. surely there must be something evolution cannot explain. can darwinian mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset theory explain every aspect of nature, or are there distinct, a priori limits to its epistemic utility? if so, are the limitations philosophical or scientific in nature? are they practical or theoretical, real or perceived? do limits arise from inadequacies of evolutionary theory itself, or merely from those who misunderstand or misappropriate it? what sorts of naturalistic questions might evolution not be able to answer? are humans exempt from ees? these questions carry profound significance for scientists, social scientists, and philosophers alike. following a historical introduction via two case studies, potential constraints on ees are considered. a third case study reinforces the conclusion that the stratagem to apply limits to ees 1) normally occurs in human context and 2) ultimately hinges upon one‘s acceptance or rejection of ontological materialism. case study 1: thomas henry huxley, darwin’s sometime supporter the accomplished nineteenth century anatomist and paleontologist thomas henry huxley (1824-1895) is best known today as charles darwin‘s colleague. darwin‘s keen mind and wit made him a fierce debater, but he shunned the spotlight and sought to downplay controversy; he privately fumed at critics but hesitated to take them on in public (browne 2002, 295). huxley, in contrast, cherished confrontation as ‗darwin‘s bulldog,‘ an outspoken champion of evolution. an eager and effective proponent, huxley defended darwin from detractors on several occasions, notably in the debate at oxford on june 30, 1860, against archbishop samuel ‗soapy sam‘wilberforce (desmond and moore 1992, 492; hesketh 2009). yet huxley challenged darwin on key points. huxley admonished darwin for arguing that evolution must necessarily be slow and gradual, contending instead that lineages might evolve rapidly: ―you have loaded yourself with an unnecessary difficulty in adopting natura non facit saltum [nature does not make leaps] so unreservedly‖ (lyons 1999, 49). huxley would feel vindicated by today‘s acceptance of variable evolutionary rates in punctuated equilibrium (eldredge and gould 1972). still, huxley acknowledged that darwin, more than wallace, deserved credit for formulating the decidedly non-teleological, non-intuitive, yet remarkably simple idea of natural selection. upon first grasping this idea, huxley is said to have remarked, ―how extremely stupid not to have thought of that!‖ (desmond 1997, 41). one would suppose that as an ardent convert and supporter of this straightforward scheme, huxley would fully embrace darwinian theory, but in at least one notable way huxley broke with it. in his best known work, evolution and ethics (1894, 36), huxley tried to reconcile his dim view of a brutal, nasty nature ‗red in tooth and claw‘ with his idealistic view of humanity. how could something so good arise from something so bad? well trained, like darwin, in uniformitarian thinking, huxley recognized the universal, unalterable permanence of physicochemical laws according to which the world operates; he presumed these axiomatic ‗rules‘ of nature hold in all times and places. but in huxley‘s mind these rules must somehow have been subverted for ethics to develop in our species. his self-perceived masterstroke was the metaphor of a garden which must ever be tended to stave off disrepair. according to irvine (1955, 414), huxley, an avid gardener, was inspired by voltaire‘s character candide, who avowed that ―il faut cultiver notre jardin‖ [we must all cultivate our own garden]. huxley readily embraced this directive. he recognized that only by the gardener‘s never-ending toil and constant energy input could inevitable decay—the entropy called for by thermodynamics—be postponed and ‗progress‘ made. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset so far, so good: darwin would object to nothing here. gardens evidently require constant care. but huxley‘s argument culminated by comparing humanity to the symbolic gardener. only by exercising similar toil, individually and collectively (as society and species), argued huxley, could humans improve their lot and avoid their bestial nature. only by removing wicked ‗weeds‘ can we become moral creatures. huxley argued (1888) that we overcome a hobbesian nature solely via cultural practice. in short, huxley saw ethics as an unnatural innovation (without biological underpinning) triumphing over evolution. as primatologist frans de waal notes (2001, 344), this was a case of the bulldog biting his master. huxley‘s argument deliberately limited evolution‘s explanatory power. in de waal‘s words (344), ―since many people consider morality the essence of our species, huxley in effect said that what makes us human is too big for the evolutionary framework.‖ darwin‘s fiercest advocate would not bring himself to subscribe to a universally evolutionary position—huxley did not imagine a morality explicable in biological terms. as the figurative gardener‘s never-ending struggle attests, huxley felt ees could go only so far, despite darwin‘s unequivocal position (stated in the descent of man, 1871, 173) of continuity between evolution and human nature, including morality. by contrast, darwin‘s bulldog plainly recognized curbs to ees. although evolution is the foundation of modern biology—in dobzhansky‘s famous phrase, ―nothing makes sense in biology except in light of evolution‖ (1973, 125)—huxley‘s tenuous position (accepting ees for all of biology with the exception of human nature) is far from unique. in the century and a half since darwin‘s idea ascended, many scholars have jumped onto this middle-ground bandwagon. even pope john paul ii, in articulating the vatican‘s official position (1996, 1) by admitting the overwhelming empirical evidence for biological evolution, nonetheless attached strict limits to its relevance in understanding ‗the truth about man,‘ specifically the ‗ensoulment‘ of individual human beings. case study 2: john harlow, darwin’s unwitting (and unheard) supporter a similar story lies at the heart of a case the opposite of huxley‘s. it involves phineas gage (1823-1860), the railroad worker whose extraordinary tale is now widely known, in part because it is as gruesome as it is incredible, and because it has gained notoriety in studies of neuroanatomy and cognition (fleischman 2002; macmillan 2002; kean 2014). it is remarkable that gage was not killed by the iron tamping rod that blew a hole through his brain, and that he soon returned to work. neurologist antonio damasio (1994, 8) extensively described gage‘s ensuing personality change—from a pleasant, shrewd, ambitious, exemplary employee to a rash, foul-mouthed, unrestrained and unreliable man—and the role of the ventromedial prefrontal cortex in regulating behavior, largely by inhibiting impulsive behavior. less widely known is the role of dr. john martyn harlow of cavendish, vermont, who treated gage‘s wound the day of the injury (september 13, 1848) and followed his recovery the rest of gage‘s life (mcmillan 2002, 106). harlow was riveted by gage‘s ability to survive his grievous injury and by its profound effect on gage‘s personality, although kean (2014, 353) casts doubts on the extent of this shift. harlow grew to appreciate the influence, if not explicit causal link, of brain on behavior. had he discovered the mythical ‗moral compass,‘ with the damaged frontal lobe relating directly to sociality (damasio 1994, 22)? mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset harlow‘s work came in the decade following darwin‘s publication of origin, at a time when mental abilities were first ascribed to specific brain regions. paul broca and carl wernicke notably described language deficits in speech production and comprehension that could be traced to distinct brain loci (the inferior frontal and superior temporal gyri, respectively). together, broca and wernicke demonstrated an unambiguous link between brain and behavior. unlike these european academic anatomists, harlow was a country doctor. nonetheless, he believed he too had conclusive evidence of a connection between a precise brain region and its corresponding higher order function. damasio (1994, 85) cites harlow‘s story as ―the historical beginning of the study of the biological basis of behavior‖ (presuming one does not invoke once-popular but now-debunked ideas about physical traits in 18th century phrenology). however, the mind-brain link harlow explored (macmillan 2002, 114) involved not language but ethics: he speculated on the realm huxley argued was inexplicable in natural terms. in contrast to huxley, harlow suggested that morality—which darwin himself recognized in descent (1871, 102) as humanity‘s defining feature—was a material phenomenon amenable to scientific investigation. where huxley defined clear limits to ee, harlow saw none. yet whereas broca and wernicke achieved scientific success and popular acclaim, harlow‘s idea gained no support—at least, none until biologists at the close of the 20th century took up the battle flag and resumed harlow‘s fight. where the mighty huxley had circumscribed limits on evolution‘s explanatory power, harlow had tried, and failed, to break through. defining terms, past and present what constitutes an evolutionary explanation (ee)? as used here, the term explicitly refers to a scientific hypothesis offering an account of the form or function of any attribute—physical, biochemical, behavioral, etc.— of an organism or taxon (a group of related organisms at any level such as species or kingdom). in a sense an ee is a ‗just-so story‘purporting to explain how something in the natural world came to be. it provides a historical explanation—a logical inference based on empirical evidence—spelling out how a feature appeared and later predominated in a given environment. as such ees rely upon the classic algorithmic routine, outlined by darwin and wallace, of novel variants (mutations) appearing and being selected for or against, with new iterations occurring in succeeding generations. although our understanding of underlying genetic mechanisms has made huge strides, in essence ees are couched in the same terms darwin and wallace used 150 years ago. commonly known as natural selection, this process involves three step-wise stages: variation, selection, and inheritance. darwin and wallace were far from the first to propose organic evolution (non-constancy of species), but they formulated the causal, mechanistic explanation for how such change occurs. although ‗natural selection‘ can be taken as roughly synonymous for what is meant here by ee, other elements of selection, including sexual, directional, disruptive, purifying, stabilizing, and artificial selection (human-induced selective breeding) also pertain. random change due to genetic drift can also occur, as will be discussed. nonetheless, when people refer to ‗darwin‘s theory of evolution,‘ natural selection is virtually always what they have in mind. though natural selection remains the centerpiece of modern evolutionary theory it is only one of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset darwin‘s many contributions that remain central today. indeed, darwin‘s theory is not a single idea but a suite of interconnected explanatory principles (hence darwin‘s ‗theories‘would be a more appropriate name), including common ancestry, gradualness of change, adaptation (link between organism and environment), macroevolution (extension of adaptation to speciation and higher-level evolution), extinction, and convergent (analogous) evolution. note that darwin did not initially like the term ‗evolution,‘ partly because previous theorists, who described a progressive unfolding, offered no causal explanation for how it might occur (bowler 1975; desmond and moore 1992, 293). instead darwin described this process as ‗descent with modification.‘ only later and reluctantly did darwin use herbert spencer‘s phrase ‗survival of the fittest‘; he might have preferred ‗amplification of the aptest‘ (allchin 2007, 176), given that less fit organisms still survive, even if they have lower fitness and less genetic representation in succeeding generations. it must be emphasized that evolution and development are disparate phenomena (werth 2014, 9): the former links a chain of organisms by common descent, whereas development refers to programmatic changes during the life history of a single organism. individual organisms do not evolve. it is also important to distinguish true phyletic adaptation (heritable change in a lineage due to genotypic change) from acute or chronic change in an organism, such as acclimatization to altitude. such physiological accommodation, although often referred to as adaptation (and likewise fully explicable in causal, mechanistic terms), is not a scenario encompassed by ee. among darwin‘s advances were his emphasis on population-level thinking (herbert 1977; ridley 2003) and his characterization of variation not as a flaw to be brushed aside or explained away, but as a key element of ees in that they furnish the material sculpted by selection. the development of population genetics that led to the ‗modern synthesis‘of the 1940s paved the way for today‘s gene-centric focus on fitness, which expanded to include behavioral traits in all animals, including humans (i.e., sociobiology and evolutionary psychology, hereafter ep). although modern studies give greater emphasis to genetic fitness, the essential concept of survival and reproduction of parent and offspring remains unchanged since darwin and wallace. there is, however, debate over the level or levels at which selection acts, ranging from gene to individual organism to population (i.e., group selection; wilson 2012; pinker 2012). ees lie at the heart of biology. they are the central organizing principle making biology a bona fide science. evolution is universally accepted as factual by scientists and other scholars. despite tremendous popular opposition, no viable alternative explanatory framework has been proposed, nor has legitimate contrary empirical evidence been advanced. nevertheless, the question remains whether this explanatory framework is universal and all-powerful. can evolution explain all features of the living world? do evolutionary explanations fit basic tenets of science? as scientific explanations, evolutionary scenarios are obliged to follow modern science‘s naturalism. ees depend on empirical data. they must be based on reliable, repeatable, objective evidence rather than mere claims or ideas. ees must be open to rejection or modification in the face of new evidence. they must be potentially falsifiable, and testability must be intersubjective: independent investigators must be able to challenge and support or disprove claims. ees are bound by rules of logic. crucially, ees must offer more than mere descriptions, for at heart science offers reasoned accounts for why things are as they are. further, such explanations must operate mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset according to a causal, non-teleological mechanism; they involve proximate (initial mechanistic) rather than ultimate causes (in the sense of purpose). all explanation must involve wholly and solely natural, material, physical causes, as opposed to supernatural, immaterial, metaphysical phenomena. though evolution leads to ordered design via selection acting on variation generated by random mutation, there is never appeal to a telos or agency beyond nature. design occurs from the ‗bottom up‘ rather than ‗top down‘ (dennett 1995, 75; shermer 2006, 65). evolution is a ‗theory‘ in the strict scientific rather than common vernacular sense (i.e., a hunch or guess; kugler 2002, 341). further, ‗darwin‘s theory‘ is an explanatory framework, not an ideology to be pinned to one man, as in the oft-pejorative phrase ‗darwinism.‘ even if darwin never developed this idea, which transformed biology from an assemblage of facts into a unified field of study, someone else would have, as wallace indeed did simultaneously. science, as a cumulative, collective, objective methodology focused on explanations of the physical world, is, ideally and in toto, ultimately independent of individual views (admittedly casting aside vast issues of philosophical realism and sociology of science). our understanding of evolution increases as a wealth of experimental and observational evidence accumulates. it might be argued that these basic stipulations (i.e., observability) constitute essential restrictions on ees. however, ees that do not fulfill these initial preconditions are scientifically invalid, so this claim is dubious at best. to the extent that ees represent bona fide science, they necessarily abide by such limits a priori. ees published in reputable, refereed publications (as admittedly not all ees are) are presumed to represent proper science; regrettably, this cannot be accepted as a given. one might argue that error bars, confidence intervals, and statistical findings also place limits on scientific explanations. however, these simply reinforce the provisional nature of ees, which are not infallible but instead change with evidence. do evolutionary explanations fit the real world, or merely a make-believe one? the best explanations are those with the fewest ontological posits, following the rule of parsimony (‗occam‘s razor‘). but does science actually tell us about nature, or does it only explain how data fit a hypothesis to be tested? does it just make simplified models that enable us to understand our perceptions of experiential phenomena in the natural world (godfrey-smith 2003, 187)? following dupré (2001, 10), holcomb (2002) argues science is limited because it merely models the actual universe, representing certain aspects of our world but not truly or totally characterizing it. is science merely a metaphor, and terms like ‗gravity‘ and ‗gene‘ linguistic placeholders signifying things we scarcely understand? natural selection is nevertheless an exceedingly simple mechanistic relationship. darwin did not need to understand generation of variation to understand how selection operates, just as physicists cannot cleanly link newtonian mechanics with einstein‘s relativity to explain gravity. it may be that punctuated equilibrium, involving gaps in the fossil record and non-linear rates of morphological change, is more a post hoc descriptive account of why gaps exist than a causal chain explaining, in a predictive sense, why that pattern exists in nature (hume 1748). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset still, to what extent must scientific explanations give causal accounts, given darwin himself did not understand inheritance, and at what level of reduction must they attribute cause? do we explain natural selection in terms of populations, genes, or subatomic particles? do evolutionary explanations show causality? as godfrey-smith (2003, 191-2) argues, to explain something in science ―is to show how to derive it in a logical argument… to show that it is to be expected, to show that it is not surprising, given our knowledge of the laws of nature.‖ under the ‗covering law‘ model of modern deductive-nomological science (hempel 1965), to explain is to give an account of something, a reckoning of cause with a relationship of inference. however, an asymmetry problem exists in that whereas we derive conclusions from premises, we cannot always go back to premises from conclusions. when we predict something we show it is expected, even if it ultimately does not occur, whereas when we explain something ―we know that it has happened already, and we show that it could have been predicted, using an argument containing a law‖ (godfrey-smith 2003, 192). because of this unidirectionality not all explanations can be reversed, and not all good arguments are good explanations. this post hoc rationalization, which shermer (1997, 216) decries as hindsight bias or ‗monday morning quarterbacking,‘ is a frequent critique lodged against ee, where prediction, as in weather forecasting, is theoretically possible if extraordinarily complicated given the number of variables involved. but the inability to predict preceding physical states, given an initial set of conditions and well-understood laws of nature, is not a special problem for ees; such ‗overdetermination‘ is a broader issue for science generally. another issue is how well ees link specific events to general patterns, connecting diverse facts under a set of basic explanatory principles. in godfrey-smith‘s words (2003, 196), ―[scientists] try to develop general explanatory schemata that can be applied as widely as possible.‖ in this regard ee is wildly successful: darwin transformed natural philosophy from scattered anecdotes into modern biology. a basic principle unifies a huge range of natural phenomena—potentially, all such phenomena. do evolutionary explanations lack predictive power? because of science‘s predictive power, it is concerned with explaining not only what is but what might be. however, critics contend that ees are limited by historical contingencies. evolution might not really explain anything because it cannot specifically predict the sorts of things (structural, behavioral, etc.) that will evolve. vertebrates evolved with pectoral and pelvic limbs; this is why they have two sets of paired appendages. but why two? why not three? unlike newtonian mechanics or other areas of physical science, where one can calculate a precise end result given a set of initial conditions, ees seem to offer ad hoc, a posteriori accounts. although one can concoct ees to explain how any aspect of any organism came about, you can‘t predict a priori that x or y will evolve. could one have expected that eyes or fins or leaves would evolve? nonetheless, the issue here concerns data, not theory. those who argue that ees are necessary but insufficient to explain life‘s diversity fail to acknowledge that given enough information, a biologist could explain specific diversity, just as a meteorologist mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset could, with sufficient data, predict all weather. the argument is not that ees should be able to predict perfectly; rather, processes that appear stochastic may when better understood be seen as more deterministic. the central issue is that ees are at heart based on statistical probabilities—an inherent element of the algorithmic mechanism proposed by darwin and wallace. you need not predict who will win a tennis tournament to be certain someone will emerge as the winner, but knowing something about the competitors, you can offer a statistical argument for who is most likely to win. ees simply propose that some evolutionary paths are more likely than others, just as it is more likely that a top seed will defeat a #64 seed in a tennis match. the set of organisms that might evolve is infinite, yet one can predict future organisms given today‘s organisms and expected future conditions (e.g., climatic trends). this is the central conceit of books like dixon‘s after man (1981), which present, as its subtitle explains, a zoology of the future. such books are patently speculative, but the conjecture is based on science underlying ees. oddly enough, as mayr (2001, 277) noted, darwin was criticized by contemporaries for focusing on specific predictions and deductions rather than grand, abstract ideas. for darwin, ee fit philosophical as well as methodological naturalism. darwin‘s view allows for natural, material, physical explanations, as opposed to the supernatural, immaterial, metaphysical explanations so common outside science. ees do not rule out the possible existence of divine forces, but neither do they require one (kitcher 2007, 129). this stripped-down simplicity of ee is, for many critics, a steep hurdle to overcome, especially when compared to the stunning complexity of the living world. how could a simple, blind process result in so much complexity? how can the living world‘s beauty and harmony depend on a probabilistic process? this critique is typically offered not as a limitation on ees but as a refutation of them in the first place. a common criticism relating to predictive ability is that whereas ee may be seen as necessary it is insufficient in explanatory power. it can explain that the necks of giraffes and mice have seven cervical vertebrae, but not why mammals have 7 instead of 6 or 8. it can explain the prevalence of the pentadactyl hand as a bauplan for tetrapod vertebrates, but not why the common ancestor had five digits rather than some other number. however, this turns out to be a weak criticism at best; again, the real problem is of limited data, not underlying theory. given sufficient information, we should be able to explain, via abductive inference, when the next mass extinction will occur and which species will survive it. that ees are historical in nature does not preclude scientists from testing them critically (cooper 2002, 427). ees are open to the same falsification, via experiment and observation, as all scientific hypotheses. darwin predicted, given the presumed relationship between humans and apes, that fossils of early human ancestors would be found where chimpanzees and gorillas live, in africa. this has been borne out by copious evidence. another example involves the evolutionary link between birds and dinosaurs. based upon skeletal similarities in the wrist and hip, scientists predicted dinosaur reproduction was like that of modern archosaurs (crocodilians and birds), including laying and brooding eggs in nests. the discovery of fossilized dinosaur eggs in nests confirmed this prediction. other ee-based predictions such as the stratigraphic and geographic distribution of fossil taxa have likewise been corroborated. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a related issue arises from the reductionism vs. emergence conundrum in that many biological properties (e.g., life, consciousness) cannot easily be distilled—they emerge later, with higher levels of organization, as epiphenomena. again, the criticism is that something that explains everything explains nothing, and thus ee is a shady, fast-and-loose shell game rather than genuine science. closer inspection reveals that given a set of initial conditions, one could predict the evolution of photoreceptors to sense visual stimuli, or contractile tissues and locomotor structures for movement, or plant organs with photoreactive pigments and high surface area for photosynthesis. there is nothing shifty or underhanded going on, except that the final solution to these scenarios is pragmatically unpredictable: we can‘t easily foretell, with the data we have, which of various possible outcomes will come to pass. as physicist sean carroll writes (2016, 293), one can explain giraffes‘ long necks via natural or sexual selection, or by arguing that ―given the laws of physics, the initial state of the universe, and our location in the cosmos, collections of atoms in the shape of long-necked giraffes came into existence 14 billion years after the big bang.‖ this statement is true but not useful, carroll claims, as it lacks the predictive power of ees. are evolutionary explanations tautological? khan (2009) points to the ‗relentless tautologies‘ offered by the evolutionary framework. he refers to the ‗ontological leap‘taken by staunch adherents to ee, particularly social scientists who purport to explain all facets of human art, religion, and history via ep. ‗survival of the fittest‘ is often unfairly painted as a tautology if one defines fittest as those that survive. however, because ee involves heritability of characters, natural selection does not merely imply that survivors survive. population genetics demonstrates and predicts when populations will or will not be altered by natural selection (shermer 1997, 143). genes conferring adult tolerance to lactose are likely to be selected for in groups of herders with ready access to milk, but not in populations without domesticated cattle, sheep, or goats. can evolution create? does it involve chance? a potential scientific complaint is that evolution cannot generate new forms because it is eliminative only, removing less fit individuals of a population. yet elimination can be creative; sculptors create by chiseling away. the ‗adaptationist program‘ criticized in gould and lewontin‘s landmark ‗spandrels of san marco‘ paper (1979) might be seen as a limit to ee. chance contingencies are not explained by evolution, though they are often subsumed within ee, as lewontin and gould noted. not all organismal features are adaptations demanding a justso story; some are historical accidents. adaptationism is a seductive siren, yet just because something makes sense as an adaptation doesn‘t mean it is an adaptation. crucially, as genes are linked, many features just ―come along for the ride‖ without being truly selected for. much genetic variation is also the result of stochastic drift; ‗neutral‘ dna is unexpressed and thus not subject to selection. in this sense, as with external aspects of an organism‘s phenotype, features might be attributed to chance events. this poses a potential limitation on the epistemic utility of ee. is evolution limited by material constraints? mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset there appear to be constraints from basic physics (which, for example, limit arthropod size), from genetics/genomics (with a limited toolkit of conserved genes serving similar functions in a wide range of organisms), and from development. this is why, even though birds with aluminum wings or mammals with goretex coats would be highly favored, they do not exist (kardong 2012, 3). as schloss (2009, 41) notes, ees offer a scenario in which a bat wing or dolphin flipper evolved as variations on the mammalian forelimb, ―but to understand them fully requires concepts outside evolution, like aerodynamics and gravity.‖ schloss (2009, 41) opines that ―evolution is a search engine that combs possibility space, but to explain what it comes up with, we need to understand both the engine and the space.‖ why are there no organisms with wheels? natural selection would greatly favor wheels, or birds with aluminum or teflon wings or horses with six legs. such extrinsic (physical) constraints allow a crucial falsifiability to ees and predictions. as long (2013, 15) notes, ―physical models can‘t violate laws of physics,‖ whereas ―every computer model is doomed to succeed.‖ new evolutionary-developmental (‗evo-devo‘) biology seeks explanations incorporating intrinsic (genetic) limitations, helping to broaden ees‘ explanatory power. is evolution limited by irreversibility? another prospective scientific limit to ee lies in the irreversibility of evolutionary change. although it is supposed that random changes in dna (nucleotide substitutions) can ‗undo‘ earlier changes, ‗dollo‘s law‘ states that evolution moves in one direction only: organisms cannot return down a road they have traveled (e.g., losing and later regaining a trait). a study by bridgham et al. (2009) offers a potential mechanism for one-way evolution, involving mutations (even in ‗neutral‘ or ‗nonfunctional‘ dna sequences unexpressed in an organism‘s phenotype) that destabilize proteins. a simple genetic reversion would not necessarily ‗undo‘ destabilizing effects of the original change, which would require, without selection pressure, an exceedingly unlikely number of neutral mutations. this ‗one-way‘ path poses a limit, but reflection yields examples of major reversals. marine mammals arose from quadrupeds; in reverting to an aquatic existence, whales gave up the legs their ancestors evolved when the first terrestrial tetrapods emerged from the sea. the loss of prismatic enamel in cetacean teeth and loss of the complexly folded neocortex in manatee brains (kelava et al. 2013) are other examples of evolutionary reversal. do social norms or sanctions guiding human behavior impose limits? from the philosophical realm, another stipulation presents a likely limit on ees: the injunction against using scientific findings as a guide for moral behavior. to borrow a famous phrase attributed to galileo (1615), scripture ―teaches us how to go to heaven, not how the heavens go.‖ science is understood not to be used as a model teaching people how to lead their lives. however, this feeling is not universally shared. much ink has been spilled concerning ‗social darwinism‘ and whether it was justifiable to darwin and other scientists, but that is not what is meant here. rather, what if ees shed light on relationships between humans, or between humans and other species, indeed all of nature? if we are morally obligated to yell ―fire!‖ when we smell smoke in a crowded room, then what if scientists possess superior smoke detectors? are they bound to share results of findings in ways that could potentially save lives? this is a key question that demands more space and attention than can be given here. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset it is essential to distinguish ideal science as an independent societal process from science as a flawed, subjective institution carried out by biased individuals. sociologists of science have studied, without arriving at a definitive conclusion (beattie 2007; dennett 2007), the ‗chicken-and-egg‘ question of whether people are prone to become scientists because of their philosophical and religious leanings or in contrast, if working as a scientist leads one to develop a secular worldview. science per se, as a literally atheistic process—where explanations involving supernatural causes are not allowed—is separate from scientists, many of whom practice diverse faiths. science has been ―permeated by groupthink, bias, and financial, political, and personal motivations‖ (bloom 2015), with false claims and faulty programs—from the third reich to marxism, with eugenics, phrenology, and stifled climate debate—because scientists are human too (guhin 2016). as neil degrasse tyson notes, ―in science, when human behavior enters the equation, things go nonlinear. that‘s why physics is easy and sociology is hard.‖ nonetheless, this demarcation between ontological naturalism (which argues there are only natural phenomena, and that whatever exists or happens is therefore natural) and science‘s purely methodological naturalism poses perhaps the greatest potential curb on ees, especially for adherents of religious or other teleological worldviews. to the extent that science is limited in theory or practice by social restraints, these must be seen as limitations to evolutionary (and all other scientific) explanations. the general issue of whether science itself has limited explanatory power, especially where it abuts belief, has attracted scrutiny, most notably by bronowski (1956), snow (1959), and medawar (1984). to be clear, science does not presume naturalism; rather, science has provisionally concluded that naturalism offers the best picture of the world, based on objective empirical evidence (national academy of sciences 1998; plantinga 2011; carroll 2016). naturalism is therefore a strength of ees, not an a priori limitation. case study 3: alfred russel wallace and moral (ontological) limitations consider wallace as a counterpoint to huxley and harlow. a prominent naturalist who supported darwin and equaled him as natural selection‘s co-discoverer, wallace nevertheless eventually, like huxley, imposed his own limits on ees‘ utility. indeed, wallace is as widely known for his late-life departure from evolutionary theory as for his joint contribution to it. notably, wallace ultimately concluded, contra darwin, that evolution is teleological and anthropocentric. wallace was a remarkably productive scientist but a puzzling person. he saw himself an ‗utter skeptic‘ (slotten 2004, 232) and purely scientific thinker, but for half his life was a proponent of spiritualism, though he claimed attempts to contact ghosts in séances involved rational, scientific efforts, given that spirits would be sensed via material means such as sounds, movements, and temperature changes. wallace publicly claimed he sought to expose fraudulent mystics as sincerely as he sought to communicate with spirits from the beyond (shermer 2002, 179), but his embrace of mysticism cannot be overlooked. there is no disguising the fact that wallace, like huxley, held a different view of evolution‘s generative powers than darwin. whereas darwin argued that purely physicochemical phenomena could create new, diverse life forms but also, presumably, the first life itself—although evolution is strictly about change in organisms, not the initial appearance of life forms—wallace saw stark limits to evolution‘s explanatory capacity, espousing the familiar view that material causes are insufficient to explain how life and human cognition arose. he wrote (1889, 478) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset that nonmaterial (supernatural) causes in the ―unseen universe of spirit‖ were alone responsible for life‘s origins, for consciousness in ―higher animals,‖ and for man‘s great powers of reason. indeed, wallace proudly proclaimed these metaphysical goals as the very purpose of the universe. thus wallace drew the ire of huxley, who criticized this teleological stance (raby 2001, 291), and darwin himself, who wrote in a letter to wallace, ―i differ grievously from you, & i am very sorry for it… i hope you have not murdered too completely your own and my child‖ (darwin 1869, milner 2014, 2). wallace‘s writings and advocacy of spiritualism, mesmerism, and phrenology have dimmed his luster among modern biologists. despite a self-professed insistence on pure scientific thinking, wallace allowed supernatural causes to enter his explanatory framework. although wallace‘s myriad contributions to tropical biology and ecology remain seminal—as the father of bioegeography, his name persists in the eponymous wallace‘s line and wallace effect— in evolutionary theory he lingers mainly as footnote to darwin. students learn of wallace as the humble codiscoverer of natural selection, but the deeper they dig the more they see why darwin found reasons to shun him (shermer 2002, xviii). two points must be stressed here. first, given that we, as corporeal beings existing in the physical world, can perceive supernatural phenomena only when manifested as empirical events capable of being experienced by our senses, then they are of necessity rendered open to scientific interpretation and analysis. in short, we have no means of perceiving exclusively supernatural (rather than partly or wholly natural) phenomena, or of knowing whether supernatural things even exist—we sense phenomena only via natural means. supernatural things may well exist, but they have no place in science (thus science‘s methodological naturalism is better characterized as empiricism: knowledge is derived not from thoughts but from experience). second, teleological explanations are similarly ‗wrong‘ only in the sense that they are entirely unscientific. in non-scientific contexts (including religious faiths) teleology can be valuable. are humans exempt from evolution? are we bound by determinism? astute readers will notice a common thread in the stories of huxley‘s garden, harlow‘s brain, and wallace‘s ghost. all involve a single species: our own. aside from possible philosophical and scientific objections to ees noted earlier, all concerns relate to humans alone. we impose limits only upon ourselves. consider the fundamental importance of this observation. no one who accepts ees claims that any aspect of a bird, butterfly, or banana is not amenable (in theory) to evolutionary interpretation. creationists aside, scientists do not argue that a paramecium, pine tree, or porcupine requires a special explanation for its morphology or behavior beyond that outlined by darwin. only when a spotlight is turned on our species do we search for additional answers; only then do we explain via ultimate causes. we present ourselves as the first and last exhibit in the list of limits on ee. aside from arguments that we have ‗outstripped‘evolution (gluckman and hanson 1996, 126), we object for religious or moral reasons. to reiterate, important questions about the origin of life do not properly fall under the purview of ee. ees deal with organismal modifications over time; life‘s appearance is a different question. this is not an attempt to hedge or dodge the issue. any scientific account of life‘s origin must unquestionably adhere to the ‗rules‘ of science mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset outlined earlier, including an empirical, natural, non-teleological position (opposite wallace‘s supernatural explanation). again, historical explanations are amenable to the scientific methods of observation and experiment, and offer the same predictive power (cooper 2002, 430). in short, darwin presented humans as animals. his view is often construed as—though it was not intended to be—an affront to human dignity and an assault on the doctrine of human exceptionalism and supremacy. if we are just animals, then what keeps us from behaving like animals? how can we exhibit morality? we now study the biological basis of ethics. morality has evolutionary roots (allchin 1999), contradicting huxley‘s claim that ethics must be an exception to evolution. primatologists like de waal (2001) argue that moral rudiments exist in other primates, particularly chimpanzees and bonobos. social apes live in tight groups, with a central social life focused on status in the dominance hierarchy and with violent, sometimes even murderous, impulses. perhaps not surprisingly, people traditionally viewed apes as aggressive, brutal fighters. but de waal and colleagues (e.g., pinker, 2002) highlight clear trends in apes toward peacemaking and reconciliation. they challenge the prevailing hobbesian (or huxleyian) view that we are born ruthless and selfish, and that without culture we remain that way. critics of ee frequently argue humans are no longer bound by the same selective processes that govern evolution of other species, whether because so much change in human populations stems from cultural rather than genetic evolution (pagel 2012), or simply because, as o‘hear (1997, 49) writes, ―our reflectiveness and our rationality‖ allow us to ―take on goals and ideals which cannot be justified in terms of survival-promotion or reproductive advantage.‖ we are not bound, as ep generally holds, by our stone age past; we make conscious decisions that differ from subconscious desires. we employ such decision-making every time we use birth control, avoid eating desirable calorie-laden foods, submit to painful medical procedures, and aid our enemies (burnham and phelan 2012; cochran and harpending 2009). humans alone are seen as transcending biological predispositions, with powers of reason, self-reflection, and cultural transmission that enable us to create new environments, subvert nature‘s tyranny, and exempt ourselves from nature‘s inexorable processes (midgely 1985; o‘hear 1997; ratcliffe 2005). gluckman and hanson (2006, ix) argue that ees do not apply to us because our bodies and behavior are no longer subject to natural selection. following a different tack, others argue that humans are exempt from natural selection‘s grasp due to our genetic engineering, particularly the way we can at least potentially alter germline dna and thus transcend selection. the use of viral vectors to introduce dna could yield ‗accelerated evolution‘ that surmounts natural processes. philosophers of science (dupré 2001, 132; holcomb 2002; ruse 2010) use the term metaphysical pluralism in criticizing ep as extending beyond the explanatory reach of evolution and science in general. critics (midgley 1985; freese 2008) disparage ep as faulty (scientifically, philosophically, ideologically) for its emphasis on determinism, mechanism, reductionism, neo-social darwinism, and vulgar adaptationism. they accuse ep of embodying bad metaphysics for its scientific imperialism and antienvironmentalism, and for uncritically accepting explanations offered to fit into an evolutionary framework, sometimes with little empirical evidence or with evidence manifestly molded to fit this procrustean bed. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset an admitted problem with ep, and a difference with other sciences, is that it too often projects wildly speculative conjectures with little hard evidence. whereas peer-reviewed science (taken collectively) hesitates to postulate inferences not backed by hard data, ep seems in many cases eager to offer far-reaching conclusions (such as about human mating or love of music) without nuanced subtlety. this is leveled as a practical criticism, not a theoretical one. ep explanations need not be limited. rather, excited writers (often journalists, not sociobiologists) are often guilty of speculating beyond the scope of what limited data imply. this revisits the problem of insufficient information, as well as whether branches of science differ methodologically or in the physical reality they reveal. are they genuinely, following wilson‘s model of consilience (1998), points along the spectrum of a larger whole, revealing related aspects of a single truth? holcomb (2002) criticizes such ‗nothing-butism‘ or ‗one-size fits all‘ explanations as metaphysical monism. o‘hear (1997, 214) offers a cogent argument that many aspects of our species, particularly moral reasoning and consciousness, are ―undarwinian‖ or ―not explicable in terms of darwinian drives.‖ he claims ―we seek truth for its own sake‖ (1997, 204) with no benefit to survival and reproduction, though this is debatable. as with all organisms, just because traits do not exhibit clearly adaptive ‗purpose‘ does not mean they did not or could not have originated evolutionarily. darwin was the first to advance a unified, non-teleological theory of evolution that did not seek refuge in aristotelian final causes. darwin‘s concept of descent involved no movement toward a goal. unlike huxley, darwin viewed nature as ever-changing but not necessarily improving, or progressing. this was a novel, unpalatable view. in mayr‘s words (1964, xvi), ―darwin postulated a brute, mechanical, soulless universe, depending on the whims of accident.‖ darwin zealously argued that survival is not a matter of mere happenstance: it is a statistically predictable property of an organism‘s makeup. however, darwinism seems to rule out choice and free will. as genetic creatures, aren‘t our features, and by extension our lives, predetermined? evolutionists are quick to distinguish the crucial difference between determinism (―the future is written‖) and potentiality: many paths lie open, some likelier than others. [some religions involve predestination to a greater extent than geneticists would claim.] in this context one must note that ‗evolution‘ literally refers to unrolling or unfolding, as of a scroll already written but not yet open to view; thus the word evolution itself carries an indelible stamp of teleology on which so much human thinking is predicated. ever since darwin biologists have debated the extent to which biological change reflects adaptation to an unpredictable, randomly changing environment, or whether evolution reflects goal-directed progress, as of the unfolding of a grand scheme. although huxley is justifiably famous for his formative views on agnosticism, he is also known for espousing a popular view of progress. then as now, the notion of divinely guided, theistic evolution was a popular middle ground in which people could keep their science and square it with theological worldviews. conclusion: limits lie in the eyes (and worldview) of the beholder according to lore (zimmer 2001, ix), an upper-class victorian lady is said to have remarked, upon the publication of the origin of species, ―let us hope this is not true; but if it is, let us hope it will not be generally known.‖ mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset alas, for this woman and millions of like-minded critics, evolutionary theory is now as universally accepted by scientists as it is widely known by non-scientists, with a deep, enduring, alluring power. as dennett predicted, evolution has spilled beyond the natural sciences to the social sciences, threatening (some would say) to account for seemingly every aspect, large and small, of humankind, as it has for all other living creatures. the explanatory power of evolutionary accounts might seem limitless. science emerges from curiosity and reflects our innate striving to apply an organizing framework to everything we experience. ‗science‘derives from the latin verb ‗to know,‘ yet although science is our most powerful tool to understand our universe, there is much science cannot answer, including the biggest questions we ask. this baffles opponents of evolution who misunderstand that science seeks explanations about the natural world, but relies on empirical evidence and addresses naturalistic questions. it cannot speak to supernatural claims. it is not suitable for addressing questions about existence, knowledge, or meaning. it cannot tell us how we should behave or what our purpose in the world should be. at heart, fundamental objections to evolutionary explanations fall into two categories: misunderstanding of the nature of science and ideological or ontological protest to evolutionary implications. if ees follow basic rules of science (viz. are based on empirical evidence, are falsifiable and predictive, and do not presume a teleological stance), there are no inherent limits qua science. to the extent that one deals with phenomena subject to empirical analysis, there may be no inherent boundaries to evolution‘s explanatory powers. it is potentially applicable to all facets of the natural world, including human culture. in the end, ees, like any scientific explanations, go only so far as science takes us. for people who feel science can answer everything—that all natural phenomena, including aspects of humanity, can be adequately explained via physical causes—there are no inherent limits to evolutionary explanations. but for the many who feel otherwise, ees have distinct limits. no one should underestimate the brute force of evolution in providing clear, consistent, consilient explanations of the natural world, but none should overestimate the case for science likewise. many who accept evolution‘s factual nature hold differing views as to its explanatory power. this was true of key figures in the development and propagation of darwin‘s theory of evolution, and will likely hold true for the foreseeable future. the teleological predisposition that lies at the heart of most objections to evolution are so deeply seated in us— both culturally and biologically (through countless generations of neurological hardwiring)—as to be virtually unshakeable. studies repeatedly show (kelemen and rosset 2009) that even when we consciously try to break the teleological paradigm, we subconsciously revert to this heuristic. as intentional creatures, it is our nature to presume agency, to seek reason and purpose in everything. this is not to say no such meaning exists in the world around us—there may well be. but that remains an open question beyond the scope of science. the point is that our default presumption is that there must necessarily be meaning. for most people, religion is the surest path to the meaning we crave, and herein lies the greatest potential curb to ee, for if there is a grand ‗meaning to it all‘ (beyond that which we impose ourselves), this scheme has the potential to exist outside the observable bounds of nature, and thus to be outside the reach of evolutionary mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 42 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset explanation. if we wish to believe in a wholly materialistic universe, with nothing exempt from ordinary laws of nature, then we can easily imagine an unalloyed, invincible, omnipotent evolutionary framework—the ‗universal acid‘ of dennett‘s metaphor—that truly explains everything in nature. but this is a massive ‗if,‘ and for most people an impossibly difficult step. the biggest, surest limit to evolutionary explanation is not to be found in the study of nature but rather in the study of ourselves, for it is a limit we willingly or unwillingly yet all too easily apply. sheldrake (2012) vigorously critiques modern science‘s unquestioned stance of mechanistic materialism. haught (2009) likewise argues that some scientists uncritically conflate ees with a materialist or physicalist worldview such that ―what emerges is not pure science but a belief system.‖ haught charges that although evolutionary biology is sound, it creeps unwarranted and unprovoked beyond science into ―realms of belief.‖ at issue is darwin‘s legacy, unintended or not, of extending methodological naturalism to ontological naturalism, a flashpoint of debate for philosophy. if scientists uncritically accept a wholly material worldview as their starting point, their results will be biased, haught (2009) argues. recall the essential uniformitarian legacy of darwin in applying scientific investigations and findings to all times and places, not excluding any portions of the material universe. but is there more to the universe than matter and energy? in haught‘s view, ees are about more than science, as they are inherently ―antithetical to religion,‖ excluding the potential for metaphysical explanations. does darwin make sense only in a materialist setting? is ee predicated on a materialist worldview? obviously not, as many people prefer theistic evolution or progressive creationism. others, including astronaut john glenn, see no problem squaring their faith with science (reid 2016): ―i don‘t see that i‘m any less religious by the fact that i can appreciate the fact that science just records that we change with evolution and time. the crux of the debate is whether one can be a serious evolutionist without being a materialist. this is a question outside science, which we may never answer to everyone‘s satisfaction. given that faith does not depend on empirical evidence, this will not soon if ever be resolved in any formal, final way. like all scientific explanations, evolutionary explanations cannot extend into the realm of belief. this is undoubtedly their strongest, surest ‗limit.‘ ultimately it boils down to the worldview one adopts. acknowledgments i dedicate this paper in memory of my late colleague diana rhoads, who never ceased to provide inspiration and tough questions, always in the spirit of graceful cooperation and learning. for a steady stream of feedback i am grateful to colleagues in biology (bill shear, mike dougherty, michael collins, douglas allchin), chemistry (herb sipe), philosophy (marc hight, patrick wilson), religion (jeff vogel, mike utzinger, jerry carney, john david ramsey), and literature (jim arieti, lowell frye). references allchin, d. (2007). a more fitting analogy. the american biology teacher 69, 174-176. barbour, i. (1998). religion and science. london: scm press. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 43 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset beattie, t. (2007). the new atheists: the twilight of reason & the war on religion. london: darton, longman, and todd. bloom, p. (2015). scientific faith is different from religious faith. the atlantic 417357. bowler, p. (1975). the changing meaning of ―evolution.‖ journal of the history of ideas 36, 95-114. bridgham, j.t., ortlund, e.a., & thornton, j.w. (2009). an epistatic ratchet constrains the direction of glucocorticoid receptor evolution. nature 461, 515-519. bronowski, j. (1956). science and human values. new york: messner. browne, j. (2002). charles darwin: a biography, vol. 2: the power of place. new york: knopf. burnham, t., & phelan, j. (2012). mean genes: from sex to money to food, taming our primal instincts, 2e. new york: perseus. carroll, s. (2016). the big picture: on the origins of life, meaning, and the universe itself. new york: dutton. cooper, r. (2002). scientific knowledge of the past is possible. american biology teacher 64, 427-432. cochran, g., & harpending, h. (2009). the 10,000 year explosion: how civilization accelerated human evolution. new york: basic books. damasio, a. (1994). descartes‘ error: emotion, reason, and the human brain. new york: picador. darwin, c. (1869). april 14 letter to a.r. wallace. cambridge: darwin correspondence project (cited 2014 may 26). http://www.darwinproject.ac.uk/letter/entry-6706 darwin, c. (1871). the descent of man, and selection in relation to sex. london: john murray. dennett, d. (1995). darwin‘s dangerous idea: evolution and the meanings of life. new york: simon & schuster. dennett, d. (2007). breaking the spell: religion as a natural phenomenon. new york: penguin. desmond, a. (1997). huxley: from devil‘s disciple to evolution‘s high priest. new york: basic books. desmond, a., &moore, j. (1992). darwin: the life of a tormented evolutionist. new york: w.w. norton & co. de waal, f. (2001). the ape and the sushi master: reflections of a primatologist. new york. basic books. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 44 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset dixon, d. (1981). after man: a zoology of the future. london: st. martin‘s press. dobzhansky, t. (1973). nothing in biology makes sense except in the light of evolution. american biology teacher 35, 125-129. dupré, j. (2001). human nature and the limits of science. oxford: oxford univ. press. eldredge, n., & gould, s.j. (1972). punctuated equilibria: an alternative to phyletic gradualism. in t.j.m. schopf, ed., models in paleobiology, pp. 82-115. san francisco: freeman. fleischman, j. (2002). phineas gage: a gruesome but true story about brain science. new york: hmh books. freese, j. (2008). the limits of evolutionary psychology and the open-endedness of social possibility. sociologica 2008(3, nov-dec.), doi:10.2383/28768. gluckman, p., & hanson, m. (2006). mismatch: why our world no longer fits our bodies. oxford: oxford univ. press. galileo, g. (1615). letter to the grand duchess christina. godfrey-smith, p. (2003). theory and reality: an introduction to the philosophy of science (science and its conceptual foundations series. univ. of chicago press. gould, s.j. (1997). non-overlapping magisteria. natural history 106, 6-22. gould, s.j., & lewontin, r. (1979). the spandrels of san marco and the panglossian paradigm: a critique of the adaptationist programme. proc. r. soc. lond. b biol. sci. 205, 581-598. guhin, j. (2016). a rational nation ruled by science would be a terrible idea. new scientist 2096315. haught, j.f. (2009). theology, evolution, and the human mind: how much can biology explain? zygon 44, 4. hempel, c.g. (1965). aspects of scientific explanation: and other essays in the philosophy of science. free press. herbert, s. (1977). the place of man in the development of darwin‘s theory of transmutation. journal of the history of biology 10:155-227. hesketh, i. (2009). of apes and ancestors: evolution, christianity, and the oxford debate. toronto: univ. of toronto press. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 45 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset holcomb, h.r. (2002). review of human nature and the limits of science, by john dupré, oxford university press. notre dame philosophical reviews. 2002.06.05 hume, d. (1748). an enquiry concerning human understanding. reprinted 1993 hackett publishing. huxley, t.h. (1888). the struggle for existence in human society. collected essays 9:195-236. huxley, t.h. (1894). evolution and ethics. reprinted 1989. princeton: princeton univ. press. irvine, w. (1955). apes, angels, and victorians: the story of darwin, huxley, and evolution. new york: mcgraw-hill. kardong, k. (2012). vertebrates 6e. new york: mcgraw-hill. kean, s. (2014). the tale of the dueling neurosurgeons: the history of the human brain as revealed by true stories of trauma, madness, and recovery. new york: little, brown. kelava, i., lewitus, e., & huttner, w. (2013). the secondary loss of gyrencephaly as an example of evolutionary phenotypic reversal. frontiers in neuroanatomy 7, 16. kelemen, d., & rosset, e. (2009). the human function compunction: teleological explanation in adults. cognition 111, 138-143. kitcher, p. (2007). living with darwin: evolution, design, and the future of faith (philosophy in action). oxford univ press. khan, r. (2009). social scientists should steer clear. the guardian, 13 february 2009. http://www.guardian.co.uk/commentisfree/belief/2009/feb/13/charles-darwin-evolution kugler, c. (2002). darwin‘s theory, mendel‘s laws: labels and the teaching of evolution. american biology teacher 64, 341-351. lyons, s.l. (1999). thomas henry huxley: the evolution of a scientist. new york: prometheus. macmillan, m. (2002). an odd kind of fame: stories of phineas gage. new york: bradford. mayr, e. (1964). introduction to on the origin of species, facsimile of the first edition. new york: atheneum. mayr, e. (2001). what evolution is. new york: basic books. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 46 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset medwar, p. (1984). the limits of science. new york: harper collins midgley, m. (1985). evolution as a religion: strange hopes and stranger fears. routledge. milner, r. (2014). three birds of a feather: darwin, wallace, and attenborough. reports of the national center for science education, 34, 1-5. national academy of sciences. 1998. teaching about evolution and the nature of science. washington, dc: national academy press. o‘hear, a. (1997). beyond evolution: human nature and the limits of evolutionary explanation. oxford: oxford univ. press. pagel, m. (2012). wired for culture: origins of the human social mind. new york: w.w. norton. pinker, s. (2002). the blank slate: the modern denial of human nature. new york: penguin. pinker, s. (2012). the false allure of group selection. edge, june 19 2012. plantinga, a. (2011). where the conflict really lies: science, religion, and naturalism. oxford: oxford univ. press. pope john paul ii. (1996). message to the pontifical academy of sciences: on evolution, delivered 22 october 1996. raby, p. (2001). alfred russel wallace: a life. princeton: princeton univ. press. ratcliffe, m. (2005). an epistemological problem for evolutionary psychology. international studies in the philosophy of science 19, 47–63. reid, a. (2016). john glenn: defender of both faith and evolution. ncse.com/blog 12 december 2016. ridley, m. (2003). evolution 2e. oxford: oxford university press. ruse m. (2010). science and spirituality: making room for faith in the age of science. cambridge univ press schloss, j. (2009). totally, for a martian. in does evolution explain human nature?, pp. 40-43. west conshohocken, pa: john templeton foundation. sheldrake, r. (2012). science set free. new york: deepak chopra books. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 47 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset shermer, m. (1997). why people believe weird things: pseudoscience, superstition, and other confusions of our time. new york: henry holt. shermer, m. (2002). in darwin's shadow: the life and science of alfred russel wallace, a biographical study on the psychology of history. oxford: oxford univ. press. shermer, m. (2006). why darwin matters: the case against intelligent design. new york: times books. snow, c.p. (1959). the two cultures and the scientific revolution. cambridge: cambridge univ. press. slotten, r.a. (2004). the heretic in darwin‘s court: the life of alfred russel wallace. new york: columbia univ. press. wallace, a.r. (1889). darwinism: an exposition of the theory of natural selection with some of its applications. london: macmillan. werth, a.j. (2014). vestiges of the natural history of development: historical holdovers reveal the dynamic interaction between ontogeny and phylogeny. evolution: education and outreach 7, 1-11. wilson, e.o. (1998). consilience: the unity of knowledge. vintage. wilson, e.o. (2012). the social conquest of earth. new york: w.w. norton. zimmer, c. (2001). evolution: the triumph of an idea. new york: harper. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset navigating the digital frontier: unleashing the potential of digital twin technology ming liang zhang, wei xing chen, yu xin guo and hui min wu xi'an research inst. of hi-tech, xi’an, china abstract: digital twin technology has emerged as a key means to promote intellectualization and digitalization in various fields. it is a technical means based on simulation, with the integration of data and model as the core. this paper provides a brief overview of the development history and definition of digital twin, proposes that digital twin consists of three basic components: physical layer, transmission layer, and virtual layer, and explains the key technologies involved such as sensing and monitoring, complex system modeling, and big data analysis. the current research on digital twins is summarized, including theory, data, and technology. typical applications of digital twins in industrial manufacturing, smart cities, aerospace, and other aspects are described. finally, the paper looks forward to the development trends of digital twin technology. digital twin technology offers real-time, reusable, and intelligent solutions for product design, experimental data collection, experimental result analysis, and prediction. the advantages of digital twin technology have been recognized by many countries, including the united states, the united kingdom, and china. as digital twin technology continues to evolve, it is expected to play an increasingly important role in the construction of digital china and the advancement of other countries towards digitalization. this paper highlights the need for further research on the key technologies of digital twin to promote its application and development. keywords: digital twin, simulation, data integration, real-time, reusable, intelligent, sensing, monitoring, complex system modeling, big data analysis, industrial manufacturing, smart cities, aerospace, development trends. 1. introduction with the continuous advancement of intelligence and digitalization in various fields, digital twin technology has received more and more attention. the united states takes digital twins as the main carrier, focusing on military and large-scale equipment and other fields; the uk has set up a digital construction center with plans to build a national twin; in 2020, china also wrote digital twins into the "14th fiveyear plan", which became an important part of the construction of digital china. as an important technical means to improve production efficiency, digital twin has great advantages in product design, experimental data collection, experimental result analysis and prediction, etc., and the research on key technologies of digital twin to promote its application and development will effectively promote china's digital process. 2. the evolution of digital twins at the beginning of the twentieth century in the aerospace field, due to high manufacturing costs, complex design, inconvenient flight test data collection and other problems, in the process of product design and development, the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset concept of "simulation" appeared. early simulations focused on physical mapping of entities to describe the internal characteristics or environmental conditions of the system. with the rapid development of computer technology, simulation technology has gradually developed into all-digital simulation based on mathematical models. however, there may be a large modeling error or inability to model the physical object in the all-digital simulation, so it is tried to connect the physical object in a certain part of the simulation loop and test it under the conditions that meet the overall system performance, resulting in semi-physical simulation. in the early eighties, "virtual reality" technology was proposed, which refers to simulating the environment through computers, so that participants can have different sensory experiences and understand the objective world from the virtual environment. due to the interactivity and realism of virtual reality technology, simulation technology has been greatly developed. with the continuous maturity of a new generation of information technology and its deep integration with simulation technology, digital twins have emerged. in 2002, professor michael grieves of the university of michigan introduced two systems, real and virtual, when demonstrating product lifecycle management [1], which laid the foundation for the emergence of digital twins. subsequently, professor grieves proposed the concept of "digital representation of physical products in physical space". in 2010, the term "digital twin" was officially proposed in nasa's technical report and defined as "the simulation process of a system or aircraft that integrates multiple physical quantities, multiple scales, and multiple probabilities" [2]. in 2012, nasa and afrl defined a digital twin for an aircraft as an integrated multiphysics, multiscale, probabilistic simulation model for an aircraft or system that utilizes the best available physical models. updated sensor data and historical data, etc., to reflect the state of the flight entity corresponding to the model [3]. as an important tool to improve efficiency, digital twin can effectively promote the integration and development of digital economy and real economy. 3. the basic components of a digital twin according to the different definitions of digital twin, the composition of common digital twin systems is proposed as shown in figure 1, which is mainly divided into physical layer, transport layer and virtual layer. figure 1: basic components of the digital twin system mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3.1. physical layer the physical layer consists primarily of modeled objects and sensing systems in physical space. modeling objects mainly include entities, various equipment, and operating environments; the sensing system mainly relies on various sensors to perceive and measure the operating state of the modeled object, and at the same time monitor the operating environment and collect data in real time. the physical layer involves sensing and monitoring technology [4]. in a complete digital twin system, the acquisition of the operating environment and the state data of the digital twin components itself is an important part of the accurate mapping and real-time interaction between all elements, all states and the whole process between physical objects and their digital twin systems. in order to establish a comprehensive iot perception system and achieve accurate monitoring of the operation situation of physical objects, perception technology needs to rely on more accurate physical measurement technology, and also need to consider the synergy between the perceived data on the surface or inside the system structure, a distributed sensor network is used to determine the spatial location and unique identification of the target to ensure that the equipment is trusted and controllable 3.2. transport layer the transport layer is the bridge that connects the physical layer and the virtual layer. the transport layer transmits the physical operation data obtained by the sensing system to the virtual layer, realizing real-time mapping from the physical layer to the virtual layer [6]; at the same time, the control instructions issued by the virtual layer are transmitted to the physical layer, thereby intervening in the operation of the entity, so that a two-way data flow is formed between the physical layer and the virtual layer. the creation and control of digital twins are based on data collected in real time, so the system needs to have faster information transmission speed and shorter latency. it can achieve high bandwidth, low latency, support distributed information collection, and have high security and high reliability. with the help of the internet of things, blockchain, 5g, quantum communication and other means, the information of the physical layer is transmitted quickly and accurately, and the security and reliability of information need to be guaranteed. 3.3. virtual layer the virtual layer is the core part of the digital twin system, which is the mapping of the physical layer in the digital space, containing a model as close as possible to the physical object and synchronized with the physical layer. the implementation of digital twin should be driven by data and supported by the model, and the twin model is a true description of the physical layer entity, mapping the physical layer from different dimensions and different aspects, so that the entity state is reflected in the virtual space. the twin data comes from real-time monitoring data and historical data at the physical layer, and is processed to drive the twin model. the establishment of virtual layer model mainly applies to complex system modeling technology. digital twin model includes visual model and mathematical model, by studying the structural composition and assembly relationship of physical entities, 3d max, solidworks and other threedimensional modeling tools can be used to establish the corresponding models of each part, and synthesize after verification to obtain a visual model reflecting the overall appearance, structure, size and other information of the physical object [7]. since the mathematical model has the characteristics of involving many disciplines, diverse forms, many types, and large quantities, it can be modeled according to the product composition relationship of different subsystems [8]. the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset connection and motion law of each subsystem of the physical object were analyzed, the corresponding mathematical model was abstracted by means of mechanism modeling or parameter estimation, and simulation tools such as matlab/simulink and modelica were used to carry out simulation research under different conditions and parameters [9]. in addition, the digital twin system can be more closely related to the actual system by modeling the environment and analyzing the operation status of the digital twin under different conditions [10]. the data received by the virtual layer usually has the characteristics of multiple types, large volume, and high application value. by establishing a corresponding database to store data, and using big data analysis technology, real-time screening and processing of data, fully activating and releasing data value, and exploring the interrelationship between different data to achieve the purpose of diagnosis, prediction and decision-making [11]. 4. current state of digital twin research at present, digital twins mainly include theory, data, technology, etc., as shown in figure 2. figure 2: digital twin research direction in terms of theoretical research, zhuang cunbo [12] reviewed the background and concept of digital twin, and introduced the specific connotation of product digital twin. tao fei [13] aimed at the establishment of digital twin models, put forward the construction criterion of "four modernizations, four can be used in eight ways" of digital twin models, and carried out research and practice on the construction theory of digital twin workshop models. jia shiqi [14] summarized the current development of digital twin technology, summarized its practical results and future application directions, and looked forward to the needs and prospects of digital twin standardization according to the current standardization process. zhou junhua [15] analyzed the development process of digital twin technology, pointed out the necessity of applying digital twin technology to weapon system research and practice, and elaborated its concept and composition. zhang dawei [16] introduced the application of digital twin technology in equipment life cycle cost management, and pointed out the existing problems and solutions, so as to provide reference for improving the cost efficiency of equipment. in terms of technical analysis, liu yang [6] analyzed the connotation, development context and significance of industrial digital twin, focused on the development direction of industrial digital twin, and put forward several mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset suggestions on its development. jiang haifan [17] put forward the concept of digital twin evolution model, and gave the application methods, key technologies and working platforms of the three evolution stages of digital twin. wang huixia [18] analyzed the main differences between digital twin technology and simulation technology, refined the key technologies involved in digital twin, and designed the basic framework and application mode of digital twin of launch vehicle control system. lu qing [19] discussed the application of digital twin technology in aircraft architecture model design, multi-model architecture integration, model parameter identification and verification, and provided important guidance and technical support for the development of aircraft models and integration tests. wang wei [20] analyzed the development and value of digital twin, elaborated the basic characteristics and architecture of digital twin, introduced the key technologies of digital twin on this basis, and finally looked forward to its development prospect. wu yan [21] based on digital twin technology, sorted out the concept of digital twin, and discussed digital twin technology in manufacturing. in terms of data processing, zhang suming [3] introduced a rocket test and launch process health management system based on digital twin technology, and carried out design optimization and performance analysis, realizing data analysis, diagnosis collaboration, and fault handling decision support. fan rui [22] discussed the application of digital twin technology in data monitoring of intelligent production systems, and discussed how to achieve an efficient combination of production site and production management. in order to solve the problems encountered in the modeling and data acquisition of digital twin workshop, zhou shuaichang [23] proposed to use the half-side folding algorithm to make the complex three-dimensional model lightweight, and the improved fuzzy c-means algorithm to improve the accuracy of the data. 5. typical applications of digital twin technology 5.1. application of digital twins in industrial manufacturing siemens has been closely following the development trend of industry 4.0 and intelligent manufacturing in germany, and has been committed to the development and application of digital twin technology in recent years, and has integrated digital twin technology into its digital strategy in the past two years. siemens uses digital twin technology to digitally design, optimize and validate production processes, modify plant layouts, select production equipment, optimize production processes, and more. the automation system is verified through virtual commissioning technology, enabling it to be commissioned quickly and efficiently on site. control the physical world in the virtual world, so that the entire workshop can achieve complete integration, so as to achieve efficient and reliable production; complete production planning, production execution and quality inspection through the manufacturing operation management system; with mindsphere, all machines and equipment can be monitored in real time to analyze and evaluate actual production. through analysis and forecasting, we can drive continuous improvement of actual production and products, thereby shortening the product design optimization cycle. in the application of machine tools, with the help of digital twin technology, enterprises can complete simulation and verification from cutting to maintenance and fault diagnosis in the digital world in advance during the development stage. it can not only save the debugging cost of mature models and extend the life cycle, but also improve the research and development efficiency of new models and reduce trial and error costs. for machine tool end users, digital twin software can be used to test cut and proofing parts without physical prototyping and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset environmental construction, which can significantly reduce the risk and cost of the machining process. in addition, users can also use the digital twin to train personnel and effectively avoid the risk of machine collisions caused by insufficient personnel experience by simulating the operating environment. 5.2. application of digital twins in smart cities urban digital twin is a technical means of simulating modeling and interactive control of the whole life cycle process of urban physical entities through the digital virtual mapping of the city, with the help of historical data, real-time data, spatial data and algorithm models, etc., which can express and present all elements of physical objects, relationships, activities, etc. in the urban physical space and social space in the digital space, so as to realize the comprehensive perception and precise control of the city and promote the intelligent and digital development of the city [24]。 during the construction of xiong'an new area, it proposed to "adhere to the synchronous planning and synchronous construction of digital city and real city", based on the theory of urban complex adaptation system, to build a digital twin of the city, so that the physical city and the digital city can be connected in real time and dynamic feedback, constantly track and identify the changes of the city, so that the "hidden order" of the city can be made visible, so as to better follow the law of urban development [25]. all elements of xiong'an new area will be built synchronously in the digital city according to the construction sequence, and updated with the development of the city, and jointly iterated, which is an ecosystem that can evolve. the biggest innovation of digital twin cities lies in the fact that physical cities and digital cities can coexist and grow together, and the virtual and real can be integrated. the digital twin technology is introduced into the urban flood disaster assessment and early warning system, and realizes the visual integration of the city by establishing an intelligent perception system covering all elements of urban flood disaster, integrating real-time data such as land, water system, and transportation. use data to realize the dynamic evolution of urban digital twin, drive urban flood disaster scenario simulation analysis and decisionmaking system, predict the development trend of flood disaster through intelligent algorithms, and automatically issue early warning signals when necessary. the optimized system solves the problems of insufficient perception and dynamic response ability of the original system and poor real-time decision-making, and integrates the functions of urban real-time rain monitoring, flood disaster assessment, disaster prevention simulation and early warning [26]. digital twin library refers to the use of physical model data and multi-scale simulation technology to comprehensively model the physical entities of the library in the virtual space in order to complete the iterative optimization of all elements, holographic intelligent monitoring, and global intelligent construction. through the whole process of data mining, operation monitoring and integrated analysis of the physical entities of the library, a new model library that can realize intelligent interaction between virtual and real is built. its essence is to build the digital expression of the physical entity of the library, realize the extension of the full life cycle service of the library, carry out virtual and real interaction, tracking and analysis and two-way real-time mapping in the virtual information space, and maintain the synchronous update of data transformation, and accurately optimize the physical services, facilities and resources of the library [27]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5.3. application of digital twins in aerospace in the design and development, manufacturing and assembly, operation and maintenance of aircraft, the introduction of digital twin technology can effectively shorten the development cycle and significantly reduce costs. by establishing a digital twin of the aircraft, the product testing and verification is completed virtually in the digital space, and defects are found in the design stage and the design is improved in time to avoid waste caused by repeated modifications [28]; in the actual production and manufacturing, the processing status of each part can be tracked in real time, and the existing manufacturing process can be continuously optimized through reasonable allocation of resources to reduce downtime; in the maintenance stage, sensors are used to monitor the status of the aircraft in real time, reflect the real flight conditions, and can realize the dynamic update of the model by combining intelligent algorithms, improve the prediction ability, and can also be used to diagnose the cause of abnormal situations and evaluate after the occurrence of failures [29]. the digital twin satellite is a collection of digital models with the same origin, data sharing, coevolution, realtime interaction, synchronization between heaven and earth, and extended survival of the physical satellite [30]. the digital twin satellite can reflect the formation process, real-time status and behavior of the physical satellite, and predict, evaluate and optimize the physical satellite in the digital space. it is the twin asset and efficiency multiplier of the whole life cycle and the whole value chain of the satellite product. on the basis of realizing the digital twin function of general aircraft, the digital twin satellite can also optimize the shape parameters and deployment process of the satellite solar wing using the entity data; and the use of digital twins for ground thermal test can further save the resources on the satellite [31]. the application of digital twins to rocket testing and launch processes can effectively improve the reliability of rocket launches. in the ground test stage, the ground digital twin system monitors and interprets the data of each instrument during the test, and at the same time identifies the abnormal data to assist the profession personnel make decisions; during the ignition take-off phase, the engine thrust status diagnosis is carried out, and the takeoff process will be performed only after the digital twin on the arrow and the ground judge that the rocket starts normally; in the rocket flight phase, the digital twin system regularly receives the data transmitted by the telemetry system, carries out real-time simulation prediction, accelerates the determination of alternative solutions when a fault is detected, and issues control instructions to the rocket to minimize the occurrence of failure [32]. 6. summary with the continuous deepening of the research on digital twins by scholars from all aspects, the technology has made rapid development in recent years. however, in the application process of digital twins, there are still problems such as the lack of unified standards, the lack of interdisciplinary integrated design platform, and the need to further improve the application of core technologies. therefore, most of the current work is concentrated in the theoretical research and experimental verification stage. nevertheless, because of the great advantages of digital twins such as virtual-reality mapping, real-time synchronization, symbiosis and evolution, it is of great significance to study its key technologies, break through the difficulties encountered one by one, and promote its application in manufacturing, aerospace, urban management, smart medical and other fields to promote china's digital process. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references dong leiting, zhou xuan, zhao fubin, et al. key modeling and simulation technology of digital twin of aircraft structure [j]. journal of aeronautics, 2021, 42(3): 113-141. wang falin, guo yaowen, gong jianhua, et al. dynamic construction method of cable assembly process model for complex electromechanical products based on digital twin [j]. computer integrated manufacturing systems,2022: 1-22. zhang suming, yue mengyun. research on health management technology of rocket test and launch process based on digital twin [j/ol]. computer measurement and control, 2021, 29(5): 8-14. [4] meng songhe, ye yumei, yang qiang, et al. digital twin and its application in aerospace[j]. journal of aeronautics, 2020, 41(9): 6-17. liu yang, zhao xu. research on industrial digital twin technology system and key technologies [j]. information and communication technology and policy, 2021, 47(1): 8-13. du yingying, luo ying, peng yibing, et al. 3d visual monitoring of industrial robots based on digital twin [j]. computer integrated manufacturing systems,2022: 1-15. li hao, tao fei, wang haoqi, et al. integrated development framework and key technologies for design and manufacturing of complex products based on digital twin [j/ol]. computer integrated manufacturing systems, 2019, 25(6): 1320-1336. li kai, qian hao, gong mengyao, et al. digital ship based on digital twin technology and its application exploration [j/ol]. ships, 2018, 29(6): 101-108. ji guang, hao jianguo, zhang zhongjie, et al. twin simulation study of flight process of quadrotor uav [j]. computer engineering and applications, 2022, 58(12): 66-73. laukotka f, hanna m, krause d. digital twins of product families in aviation based on an mbseassisted approach[j/ol]. procedia cirp, 2021, 100: 684-689. yin haijun, xiao tangwei, li xin. technical framework for digital twin workshop control of production line [j/ol]. modern manufacturing technology and equipment, 2021, 57(10): 1-6. [12] zhuang cunbo, liu jianhua, xiong hui, et al. connotation, architecture and development trend of product digital twin [j/ol]. computer integrated manufacturing systems, 2017, 23(4): 753-768. [13] tao fei, zhang he, qi qinglin, et al. theory and application of digital twin model construction [j/ol]. computer integrated manufacturing systems, 2021, 27(1): 1-15. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset jia shiqi, han li, qin chao, et al. research on digital twin application and standardization requirements [j]. information technology and standardization, 2021(11): 18-22+30. zhou junhua, xue junjie, li heyu, et al. some thoughts on digital twin of weapon system [j/ol]. journal of system simulation, 2020, 32(4): 539-552. zhang dawei. application of digital twin technology in equipment life cycle cost management [j]. command control & simulation, 2022, 44(3): 122-127. jiang haifan, ding guofu, xiao tong, et al. digital twin evolution model and its applications in intelligent manufacturing[j]. journal of southwest jiaotong university, 2022, 57(6): 1386-1394. wang huixia. research on digital twin technology and its application in space control[c/ol]. chinese society of simulation, 2021: 387-393. lu qing, wu shuang, zhao zhe, et al. application of digital twin technology in aircraft design verification [j/ol]. civil aircraft design and research, 2019(3): 1-8. wang wei, liu yongsheng, liao jun, et al. key technologies and architecture of digital twin [j]. post and telecommunications design technology, 2021(8): 10-14. wu yan, wang xiaojun, he yong, et al. review of key technologies and applications of digital twin in manufacturing industry[j/ol]. modern manufacturing engineering, 2021(9): 137-145. fan rui, liu qingchuan, gao jian. data monitoring technology of intelligent production line system based on digital twin [j/ol]. ic application, 2021, 38(11): 120-121. zhou shuaichang, liu lilan, gao zenggui. model and data acquisition optimization of digital twin workshop [j]. industrial control computer, 2021, 34(12): 14-16. national beacon committee smart city standards working group. white paper on urban digital twin standardization (2022 edition)[r/ol]. [2022-09-20]. zhou yu, liu chuncheng. the logic and innovation of building a digital twin city in xiong'an new area [j]. urban development research, 2018, 25(10): 60-67. li qiang. analysis of urban flood disaster assessment and early warning system based on digital twin technology [j]. journal of beijing university of technology, 2022, 48(5): 476-485. li jingmin, tang yi, li keyu. research on the application of digital twin technology in library construction [j]. information exploration, 2022(3): 77-82. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 4; july august 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cui yihui, yang bintao, fang yi, et al. application of digital twin technology in aero-engine intelligent production line [j/ol]. aero engines, 2019, 45(5): 93-96. zhang lei. research on predictive maintenance model of equipment based on digital twin [j]. special equipment for electronics industry, 2021, 50(3): 12-15. cui yufu, liu zianjia, wang jing. development and prospect of digital twin satellite technology [j]. space international, 2021(10): 27-31. cui yufu, liu zianjia, wang jing. digital twin satellite technology and engineering practice [j]. spacecraft engineering, 2021, 30(6): 62-69. zhang suming, yue mengyun. research on health management technology of rocket test and launch process based on digital twin [j/ol]. computer measurement and control, 2021, 29(5): 8-14. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset investigatory analysis of energy requirement of a multi-tenant mobile communication base station abonyi dorathy obianuju, okafor patrick uche and arinze stella ndidi. department of electrical and electronic engineering, enugu state university of science and technology doi:https://doi.org/10.5281/zenodo.15050984 abstract: energy consumption in mobile communication base stations (bts) significantly impacts operational costs and the environmental footprint of mobile networks. this study examines the energy requirements of a multi-tenant bts, focusing on power consumption patterns, key energy-intensive components, and optimization strategies. empirical measurements under varying load conditions revealed that power consumption is network load-dependent and time-dependent, with peak demand occurring between 9:30 am – 2:30 pm and 7:30 pm – 11:30 pm. the multi-tenant bts required approximately 7.67 kw, compared to 2.5 kw for a single-tenant bts. additionally, the annual cost of diesel for generator power was estimated at ₦17,712,000, emphasizing the financial strain of conventional energy sources. a standalone solar power system is recommended as a sustainable alternative, designed to meet the identified power demands. a multi-tenant bts model is also presented as a test-bed for designing and simulating a suitable solar power system. power amplifiers and cooling systems were identified as the most energy-intensive components. implementing dynamic load management and renewable energy solutions can significantly reduce energy demand, enhance efficiency, and lower operational costs. this study offers practical recommendations for optimizing energy use in multi-tenant bts operations, supporting cost-effective, reliable, and sustainable mobile network infrastructure. keyword: energy efficiency, mobile network sustainability, multi-tenant base station, power consumption, solar power system. 1.0 introduction mobile communication base stations (bts) play a critical role in the operation of wireless communication networks, providing connectivity for voice, data, and multimedia services (abonyi & rigelsford, 2018) . as the demand for mobile services continues to grow, driven by the proliferation of smartphones, iot devices, and high-speed internet, the energy consumption of base stations has become a significant concern. studies indicate that bts operations account for approximately 60-80% of the total energy consumption of mobile networks, making them a primary contributor to operational costs and environmental impacts (hasan et al., 2021; zhang et al., 2022). the introduction of multi-tenant base stations, where multiple mobile network operators (mnos) share infrastructure, has been widely adopted as a cost-effective solution to reduce capital expenditures (capex) and optimize resource utilization. however, this approach introduces new challenges, particularly in energy mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset management, as varying traffic loads and operational requirements from different tenants create complex energy demand patterns (li et al., 2020). for instance, peak energy consumption often coincides with high traffic loads, leading to inefficiencies and increased operational costs (buzzi et al., 2021). recent research has highlighted the need for innovative strategies to address the energy challenges of bts operations. renewable energy integration, such as solar and wind power, has emerged as a promising solution, with studies showing potential energy offsets of up to 40% in regions with high solar irradiance (ahmed et al., 2022). additionally, energy-efficient hardware, such as advanced power amplifiers and cooling systems, has been shown to reduce energy consumption by up to 30% (kumar et al., 2021). dynamic power management techniques, including tenant-based load balancing and real-time energy monitoring, have also gained attention for their ability to optimize energy use in multi-tenant configurations (zhao et al., 2023). these techniques leverage traffic data and predictive algorithms to allocate energy resources more efficiently, reducing wastage and improving overall system performance. despite these advancements, there is limited research specifically focused on the energy requirements and optimization strategies for multi-tenant bts in developing regions, where unreliable energy infrastructure and high operational costs pose additional challenges. this study aims to bridge this gap by investigating the energy consumption patterns of multi-tenant bts, identifying key energy-demanding components, and evaluating the potential of renewable energy integration and dynamic power allocation strategies. by providing a comprehensive analysis of energy requirements and optimization opportunities, this research contributes to the broader goal of achieving sustainable and cost-effective mobile network operations. it also aligns with global efforts to reduce carbon footprints and promote green telecommunications, as emphasized in the united nations sustainable development goals (un sdgs) (united nations, 2023). 2.0 methodology a typical mobile network base station (bs) was investigated with the aim of determining the load requirement, the power consumption and subsequently the maximum power required to power such base station. this will help in determining the capacity of the renewable energy system required to power a multi-tenant mobile communication base station. an outdoor macro-cell bs with site number t4733 situated at ogoja road, abakiliki and managed by ipt power tech limited was investigated. the bs shown in figure 1 is a three tenant bs housing airtel nigeria limited, mtn nigeria limited and 9mobile nigeria limited. the airtel network provider is operating a 2𝐺, 3𝐺 𝑎𝑛𝑑 4𝐺 networks , mtn is operating 2𝐺 𝑎𝑛𝑑 3𝐺 while 9mobile is operating only 2𝐺 network. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 42 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1. outdoor macrocell bts t4733 site the site comprises two main power sources, a generating set and a battery bank. the generator rating is 21kva which is 17kw connected in series and then parallel. the battery bank is made up of 36 batteries each with a rating of 7.5v/160ah. the switching between these two sources is controlled by the automatic transfer switch system referred to as power solution. the 220vac from the generator is converted to 54vdc by the rectifier. the output of the rectifier charges the battery banks as well as feeds the distribution board which supplies power to all base station equipment. the antennas were mounted on a 36m high mast and connected to the radio units at the base station via feeder cables. the power consumption of the site was obtained by actual real-time measurement of the voltage and dc flowing through the electricity supply cable of the base station equipment using clamp-on meter and probe wires. measurement carried out at the energy consumption box during the period of measurement (1300hours) shows that the available power for the cell site is 7666w i.e. ≈ 7.666kw. to obtain sufficient data for proper analysis and reasonable conclusion, recorded data was obtained from the bts performance and monitoring software tool for a period of one month at an interval of five minutes from 20th january, 2024 to 18th february, 2024. the collected data was used to carry out the following analysis; 3.0 results and analysis 3.1 effect of load on power consumption of the bs to investigate the effect of load on power consumption of a typical bs, load power data from 20/01/24 to 18/02/24 for a 5 minutes interval was plotted as shown in figure 2. this result reveals a drop in power consumption between 12 midnight and 7am and then a gradual rise with peaks between 9.30am and 2.30am. there is another gentle rise in power consumption between 2.30pm and 12midnight with peaks between 7.30pm mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 43 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and 11.30pm. the graph follow the same pattern for each day for all 30 days under investigation. it can therefore be deduced that power consumption in a mobile network base station is subject to the network load which is dependent on the time of the day. from the graph, it can be concluded that busy hours in a mobile base station is between 9.30am and 2.30pm which can be described as office hours and also between 7.30pm and 11.30pm which can be described as leisure hours. since load has affects the power consumption of a bs, a renewable energy system can be designed for either;  busy hour with a power requirement of about 6081w6638w  less busy hours with a power requirement of about 4207w 5531w  both busy and less busy hours with a power requirement of at least 7666w as physically measured. figure 2. relationship between system power and time 3.1.2 relationship between weekday and power consumption of a bs 0 1000 2000 3000 4000 5000 6000 7000 8000 0:00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 19:12 21:36 0:00 sy st em p o w er in w at ts time in seconds system power in watts for a 30 day period (20/01/21 to 18/02/21) day 1 day 2 day 3 day 4 day 5 day 6 day 7 day 8 day 9 day 10 day 11 day 12 day 13 day 14 day 15 day 16 day 17 day 18 day 19 day 20 day 21 day 22 day 23 day 24 day 25 day 26 day 27 day 28 day 29 day 30 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 44 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to investigate if the power consumption of a mobile network is dependent on the weekday or weekends. the average system power per day from 20/01/24 to 18/02/24 (30 days) at an interval of 5 minutes was calculated and plotted as shown in figure 3. this result is analyzed in table 1. table 1: analysis of relationship between system power and week day weeks minimum power maximum power 1 sunday wednesday 2 thursday friday 3 thursday friday 4 monday wednesday from table 1, wednesdays and fridays are suspected high traffic days but further investigation with more data is required before statistically significant conclusion can be drawn. figure 3. relationship between system power and days of the week 4600 4700 4800 4900 5000 5100 5200 5300 5400 5500 5600 w ed th u r fr i sa t su n m o n tu e w ed th u r fr i sa t su n m o n tu e w ed th u fr i sa t su n m o n tu e w ed th u fr i sa t su n m o n tu e w ed th u sy st em p o w er in w at ts days of the week system power against days of the week week 1 week 2 week 3 week 4 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 45 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3.3 effect of priority of a network on the base station power consumption information gathered revealed that in case of insufficient power at the base station visited, one tenant of the base station is normally given priority over others based on their commitment to funding the base station. from figure 2, the sudden power drop between 5.25am-6am and 9.55am-10am on day 5 and also between 11.35am12.50pm on day 24 and also 1.20-2.00pm on day 28 and 9.45pm-11.20pm on day 27 are most likely going to be due to one network being given priority over others. this means that at this time only one network provider’s facility is powered. the minimum and maximum system power at these times are 1858w and 2323w respectively. it can therefore be deduced that a renewable energy system can be designed for a single tenant base station with a system power output target of 2.5kw. 3.4 comparison of system measured power and actual system power comparing the actual measured system power and the system power data obtained from the bs performance and monitoring software tool, it can be observed that the actual measured data at 1300hours on the day of visit was 7666w but the system measured power at the same time on a different day was 6638w. this is actually, the maximum power for the whole month and it is 1028w less than the actual measured data. this is an indication that the system is not very 100% accurate. this means that to design a renewable energy system for a multi-tenant base station, a considerable tolerance needs to be observed in determining the power rating of the system to ensure loads are comfortably powered without over-stressing the power system. 4.0 cost implication of running a multi-tenant base station the generator on the visited site has a rating of 21kva (17kw). information obtained revealed that the generator average working hour is 8hours/day. the average diesel consumption per hour is 0.3liters/kwhour. the relationship between the output energy and consumption of diesel engine is given by equation 1. 𝐸𝑛𝑒𝑟𝑔𝑦 𝑖𝑛 𝑂𝑢𝑡𝑝𝑢𝑡: 𝐸 = 𝑃 × ℎ × 𝑑 (𝐾𝑊ℎ) (1) 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 𝑜𝑓 𝑓𝑢𝑒𝑙: 𝐶 = 𝐸 × 𝐶𝐾𝑤ℎ(𝑙𝑖𝑡𝑟𝑒) (2) where; 𝐸 active energy in the output of the diesel engine in kwh 𝑃 active electric power in the output of the diesel engine in kw ℎ number of hours per day the gen set runs 𝑑 – number of days the power generator runs 𝐶𝐾𝑤ℎ consumption of fuel per kwh (usual value is between 0.3 and 0.6liter/kwh) c – consumption of fuel in litre the energy output of the bs per day is deduced using equation 1 as follows; 𝐸𝑛𝑒𝑟𝑔𝑦 𝑖𝑛 𝑂𝑢𝑡𝑝𝑢𝑡: 𝐸 = 17 × 8 × 1 (𝐾𝑊ℎ) 𝐸𝑛𝑒𝑟𝑔𝑦 𝑖𝑛 𝑂𝑢𝑡𝑝𝑢𝑡: 𝐸 = 136 (𝐾𝑊ℎ) the fuel consumption of the on-site generator for 8hours deduced using equation 2 is as follows; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 46 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 𝑜𝑓 𝑓𝑢𝑒𝑙: 𝐶 = 136 × 0.3𝐾𝑤ℎ(𝑙𝑖𝑡𝑟𝑒) 𝐶𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 𝑜𝑓 𝑓𝑢𝑒𝑙: 𝐶 = 41(𝑙𝑖𝑡𝑟𝑒) a litre of diesel around the study area at the time of study was ₦1,200/litre. this means that an eight hourly diesel consumption of the bs for 41litres/8hour diesel consumption was ₦49,200/day and ₦1,476,000/month assuming an average of 30 days per month. this is about ₦17,712,000/year. this is quite expensive but with a renewable energy source like solar energy implementation, this cost will be saved over the years. 5.0 power model for a multi-tenant base station the model of the investigated bs power system was developed as shown in figure 4. it shows the power architecture and the basic components of the bts. figure 4. power architecture and components of the bts the base station power solution shown in figure 4 monitors the process of output power of the generator, charging of the batteries and required power to the base station, using the following scenarios: sector antenna rectifier power amplifier digital signal processing transceiver ac dc power amplifier digital signal processing transceiver power amplifier digital signal processing transceiver bu s ba r monitoring system security and lighting power solution mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 47 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset scenario 1: the generator charges the batteries. the batteries fully charged at 54v supply the base station components till they dissipate to a maximum depth of discharge (dod) of 48v. scenario 2: the generator at battery maximum dod of 48v switches on, supplying the base station components and recharging the batteries as well. the key components of the bts are presented in table 2. the power consumption of each of the components is used to determine the total power consumption of the bts. table 2: key components of the base station key components (parameters) parameter power denotation baseband unit digital processing unit 𝑃𝐷𝑆𝑃 transceiver 𝑃𝑇𝑋𝑅 amplifier 𝑃𝐴𝑀𝑃 rectifier 𝑃𝑅𝐸𝐶𝑇 microwave link 𝑃𝑀𝐼𝐶𝑅𝑂 environmental monitoring system 𝑃𝐸𝑀𝑆 security and lightings 𝑃𝑆𝐿 the essence of developing the power model of the base station is to aid in determining the power consumption of the cell site per day (cpd). it will also help in determining the power output of the base station through simulation. the cpd will be used in calculating the cost of running the site at any point in time. power p consumed by each component of the base station is given by: p = iv (3) from equation (1), the measured current varies with the traffic load for some components thus, the power consumption of a cellular base station can be categorized into two; load dependent pload and load independent pnon−load. therefore, the total power consumed by the base station is given by: pbs = pload + pnon−load (4) where, pload = ptxr + pamp (5) while pnon−load = prect + pdsp + pmicro + ∑ psl +n n=1 ∑ pems m m=1 (6) where m and n are the number of environmental monitoring systems (ems) and security and lighting (sl) respectively. the characterized three tenant base station is a tri-sector macro-cell with 120o coverage antennas mounted on a mast of … height. the power consumption of the base station components will be multiplied by the number of sectors psector. the antenna is considered to be part of the radio transceiver unit (txr). the remote radio unit (rru) comprises the transceiver and the amplifier thus, the power consumed by rru can be calculated as: prru = pload (5) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 48 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset for this base station, the number of sectors is 3. apparently, the power consumption is determined using: prru = psector0 + psector1+ psector2 (6) therefore, prru = ∑ psector 2 n=0 (7) the total power pbs consumed in the base station is deduced as follows: pbs = ∑ psector 2 n=0 + prect + pdsp + pmicro + ∑ psl +n n=1 ∑ pems m m=1 (8) measurement carried out at the energy consumption box during the period of measurement in line with equation (8) shows that the available power for the cell site is 7666w i.e. ≈ 7.666kw. to determine the power consumption of the individual service providers, measurement was carried out in accordance with equation (6) and the values achieved were tabulated in table 3. table 3: daily power consumption of the three network providers network provider network type voltage v current i(amp) power p(w) mtn 3g 48.3 36 1,738.8 mtn 2g 48.3 22 1,062.6 airtel 2g, 3g, 4g 48.3 65 3,139.5 9mobile 2g 48.3 33 1,593.9 total 7,534.8 from equation (8), power consumed for various categories of equipment can be deduced using communication and non-communication equipment. power consumption using communication equipment is given by: ∑ psector 2 n=0 + prect + pdsp + pmicro while non-communication equipment is given by: ∑ psl +n n=1 ∑ pems m m=1 from table 3, the total power consumed by the communication equipment of the base station is; ∑ psector 2 n=0 + prect + pdsp + pmicro= 7,534.8w measurement carried out on the base station environmental monitoring, security and lighting yields: ∑ psl +3 n=1 ∑ pems 1 m=1 = 90w power consumption per day (cpd) can be deduced as: 7,534.8 + 90 = 7624.8w ≈ 7.625kw power losses ploss can be determined through the difference between the available power and consumed power; 7.666kw – 7.625kw = 0.041kw 5.0 simulink model of the multi-tenant bs using the above scenarios, the power consumption model of the investigated base station was implemented in the simulink simscape environment for simulation as shown in figure 5. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 49 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: simscape model of the base station the simscape power model of the base station is designed such that the three-phase alternating current from the generator source is connected to a distribution transformer. the distribution transformer steps down and changes the voltage to single-phase ac (200 v). the frequency of ac cycles is set to 50 hz. the battery bank is a dc power source. both the generator and the battery bank are connected to the bus bar through the bts power solution. as a typical load change in a bts, the amount of electric power load reaches peak consumption at time between 9.30am and 2.30pm (6,081w to 6,638w) and between 7.30pm and 11.30pm (6,053w to 6,263w). the simulation is carried out based on the following:  from 6am to 12pm and from 6pm to 12am, battery control is performed by battery controller. the battery control performs tracking control of the current so that active power which flows into system power from the secondary side of the pole transformer is set to 0. then, the active power of the secondary side of the distribution transformer is always around zero. the battery bank supplies insufficient current when the power of the generator is cut off.  from 12pm to 6pm, battery control is not performed. soc (state of charge) of the battery bank is fixed to a constant and does not change since charge or discharge of the storage battery is not performed by the battery controller. at 8am or in a system collapse situation, the electricity load of the non-priority tenant is set to off for a stipulated time by the breaker. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 50 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5.1 simulation result the result obtained from the simulation model of the bs is shown in figure 6 figure 5: simulation graph model of the base station in figure 5, from the range scale (0 4.4 × 104 ), the zero flat lines of the generator (power secondary) showed that no energy is supplied by the generator. hence, the power solution monitors the state of charge (soc) of the battery which was fully charged and switches the load to the batteries. the batteries only feed the load and it can be seen that the movement of the power variation of the load is consistent with the battery. as the depth of discharge of the battery reduces to a certain level, the power solution starts the generator (from the range scale of 4.4 6.5 × 104) and switches the load to the generator. at the same time, the generator becomes a battery charger. the movement of the power variation of the generator is inconsistent with the load since the generator is feeding the load and charging the batteries at the same time. it can be seen that the “power_battery” is at zero levels and the graph of soc is constant which means that the battery is not discharging. the range scale of 6.59 𝑥 104 shows that the power solution has switched back to the batteries, the load is being driven with the power from the batteries and the depth of discharge of the battery is reducing. in conclusion, the simulation result conforms to the existing power system flow of the characterized base station making it a suitable test bed for the design and simulation of a renewable energy system for energy optimization in a mobile communication base station. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 51 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 6.0 conclusion this study highlights the critical role of energy management in multi-tenant mobile communication base stations, where diverse traffic loads and shared infrastructure introduce unique challenges. the findings reveal that power amplifiers and cooling systems account for the majority of energy consumption, making them prime targets for optimization. renewable energy integration, dynamic power allocation, and tenant-based load balancing are identified as effective strategies for reducing energy demand and operational costs. moreover, the study underscores the importance of adopting energy-efficient technologies and implementing proactive maintenance to enhance system reliability and sustainability. by addressing these factors, mobile network operators can achieve significant cost savings while contributing to environmental sustainability. future research should focus on developing real-time energy monitoring systems and advanced optimization algorithms to further enhance the energy efficiency of multi-tenant base stations. this work provides a foundation for sustainable practices in mobile network operations, aligning with global efforts to reduce carbon footprints and promote green telecommunications. acknowledgement the authors sincerely appreciate the nigerian communications commission (ncc) for sponsoring this research through enugu state university of science and technology (esut). their financial support and commitment to advancing telecommunications research have been instrumental in the successful execution of this study. we also acknowledge esut for providing the necessary resources and an enabling environment for this research. reference abonyi, d., & rigelsford, d. (2018). a system for optimizing small-cell deployment in 2-tier hetnets. 2018 ieee 23rd international workshop on computer aided modeling and design of communication links and networks (camad), 1–6. https://doi.org/10.1109/camad.2018.8514981 ahmed, s., li, w., & zhao, t. (2022). renewable energy integration for green mobile networks: a comprehensive review. renewable energy journal, 58(3), 122–137. https://doi.org/10.1016/j.renene.2022.01.003 buzzi, s., poor, h. v., & zappone, a. (2021). energy-efficient strategies for 5g multi-tenant networks. ieee transactions on communications, 69(4), 2356–2370. https://doi.org/10.1109/tcomm.2021.3052301 hasan, z., boostanimehr, h., & bhargava, v. k. (2021). energy-efficient cellular networks: a survey of research challenges and solutions. ieee communications surveys & tutorials, 23(1), 524–540. https://doi.org/10.1109/comst.2021.3012311 kumar, r., singh, d., & gupta, p. (2021). advanced cooling systems for energy-efficient mobile base stations. energy efficiency journal, 14(2), 78–92. https://doi.org/10.1007/s12053-021-09928-3 mailto:topacademicjournals@gmail.com https://doi.org/10.1109/camad.2018.8514981 https://doi.org/10.1016/j.renene.2022.01.003 https://doi.org/10.1109/tcomm.2021.3052301 https://doi.org/10.1109/comst.2021.3012311 https://doi.org/10.1007/s12053-021-09928-3 academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 52 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset li, y., xu, s., & wu, z. (2020). multi-tenant base stations: opportunities and challenges in energy management. ieee wireless communications, 27(2), 8–14. https://doi.org/10.1109/wc.2020.8962123 united nations. (2023). sustainable development goals. united nations. https://sdgs.un.org zhao, y., tang, j., & blume, o. (2023). dynamic power allocation for energy-efficient multi-tenant base stations. ieee transactions on wireless communications, 22(4), 1095–1107. https://doi.org/10.1109/twc.2023.3014520 mailto:topacademicjournals@gmail.com https://doi.org/10.1109/wc.2020.8962123 https://sdgs.un.org/ https://doi.org/10.1109/twc.2023.3014520 060906-mf604 academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset deep koopman neural networks for nonlinear process monitoring in stochastic production systems song, yu-jie and ma, jian-guo east china university of science and technology, shanghai, china abstract: stochastic production systems (sps) play a pivotal role in industries such as fermentation, pharmaceuticals, and composite material production, where stringent quality constraints are paramount. to ensure product quality in such systems, effective process monitoring is imperative. however, sps presents significant challenges due to its inherent stochasticity and measurement uncertainties, stemming from sensitivity to exogenous factors and the lack of accurate in-situ measurements. this paper explores the landscape of sps process monitoring methods, highlighting their limitations and proposing a novel approach leveraging recurrent neural networks (rnns), particularly long short-term memory (lstm) networks. keywords: stochastic production system, process monitoring, recurrent neural networks, long short-term memory, quality constraints. introduction: stochastic production systems (sps) have found applications in diverse fields, including fermentation, pharmaceuticals, and composite material production [1]-[7]. these applications demand stringent quality control measures to ensure the desired product quality. however, sps presents unique challenges for process monitoring due to its inherent stochastic nature and measurement uncertainties, making effective quality control a complex endeavor. this introduction sets the stage for the exploration of process monitoring methods in sps, emphasizing the need for innovative approaches. sps exhibits significant intrinsic stochasticity, primarily attributed to its sensitivity to various exogenous factors such as input variations, environmental conditions, and equipment status. these factors can introduce substantial variability in the quality and performance of the final product. moreover, the lack of accurate in-situ measurement methods adds an extra layer of noise to the available data, making process monitoring in sps indispensable yet inherently challenging. over the past few decades, researchers have developed several methods for sps process monitoring. one prevalent approach is the application of multiway principal component analysis (pca) [8]. while this method offers simplicity, low-dimensional computation, and fast processing of high-dimensional data, it is inherently linear and struggles to capture nonlinear dynamics—a prevalent feature in sps. to address the limitations of linear methods, researchers have explored kernel methods, which map data into high-dimensional feature spaces where linearity can be preserved [9]. additionally, there have been efforts to enhance independent component analysis (ica) methods [10], propose novel strategies like the kernel icapca method [11], and develop multiway kernel entropy ica methods [12]. these approaches aim to capture the nonlinear and non-gaussian characteristics inherent in sps data. furthermore, support vector machines (svm) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset integrated with pca or fuzzy reasoning have been employed for anomaly detection in sps [13], [14]. however, these methods have limited capacity to handle heavy-tailed and multimodal sps data, and their hyperparameter tuning can be cumbersome. the universal approximation theorem underscores the potential of neural networks to represent any function between inputs and outputs [15], making them an attractive option for sps process monitoring. auto-associative neural networks [16], [17] and deep neural networks [18]-[22] have been extensively explored for this purpose. however, these methods often assume sample independence and overlook dynamic correlations, limiting their effectiveness in capturing the complexities of sps data. recurrent neural networks (rnns), particularly long short-term memory (lstm) networks [23], offer a promising alternative for sps process monitoring. lstms excel at predicting future system evolutions based on current and historical data, making them well-suited for anomaly detection [24], [25]. nevertheless, their use is sometimes criticized for their limited interpretability, as they provide few insights into the underlying physical processes. in this paper, we delve into the application of lstm networks for sps process monitoring, aiming to overcome the limitations of existing methods and provide a deeper understanding of the monitored systems. our proposed approach leverages the predictive power of lstms while striving to enhance interpretability, ultimately contributing to more effective and insightful sps process monitoring. 2. problem statement the most representative example of sps is biochemical systems, and hence we will focus on it to showcase the developed method in the rest of the paper. the essence of biochemical systems is to convert substrates into highvalue-added metabolites by living organisms (mostly cells). one of the major impediments for biochemical system production in high quality and quantity stems from the existence of a subpopulation of cells showing remarkably reduced production efficiency and capacity, which is termed as population heterogeneity in synthetic biology [1]. such heterogeneity is an inevitable consequence of stochastic gene expression, which is solidly supported by massive single-cell experiments [39], [40]. in the context of biochemistry, gene expression indeed consists of a set of biochemical reactions with the participation of various macromolecules harbored in microscopic reactors (cells). the scarce of such macromolecules and the random molecular collision in the crowding reaction compartment of limited volume collectively lead to the stochasticity of intracellular biochemical reaction, particularly gene expression. as such, it is plausible to focus on gene expression process, which is the most critical and representative part. without any loss of generality, any intracellular biochemical reaction can be described by (1) where stands for species ( ), the stoichiometric coefficients and are nonnegative integers specifying the molecule numbers of reactants and products involved in reaction respectively, and is the rate constant of reaction . in the stochastic sense, is inversely proportional to the mean time of two successive reactions. the propensity of reaction is (2) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset with being the compartment volume and being the molecule number of reactant . indeed, the propensity can be loosely understood as the probability of reaction occurrence. for instance, the transcription can be compactly described by (3) where stand for gene and messenger rna (mrna) respectively, and is the transcription rate constant. besides, there are various exogenous factors perturbing the normal operation of biochemical system, such as temperature fluctuation and contamination. the temperature impacts the reaction through reaction constants according to arrhenius law. arguably, so is the mechanism of contamination, as contamination may affect the catalytic efficiency of some enzyme. hence, within the framework, when an anomaly takes place, it is reflected through the change of one or a group of reaction rate constants . the goal of process monitoring then becomes detecting anomaly from the data of reaction species if some reaction rate constant changes. 3. methods 3.1. data acquisition the dynamics of system (1) can be simulated by the renowned stochastic simulation algorithm (ssa), also known as gillespie algorithm in systems biology [41]. the basic idea is to draw two random numbers, one for calculating the next reaction time, and the other for determining next reaction type. the pseudocode for ssa is presented as follows. algorithm 1 stochastic simulation algorithm 1: initialization: 2: repeat 3: calculate propensities according to (2) 4: obtain the time step to the next reaction event 5: determine the next reaction event 6: update time 7: update according to (1) 8: until output: notably, there is a julia implementation developed by our group and available on github as delayssatoolkit. the package is based on diffeqjump, but more powerful as it is even able to simulate delayed reactions [42]. 3.2. koopman operator theory here we present a brief summary of koopman operator theory. for more details, readers are encouraged to refer to [43]. considering a discrete-time system, whose dynamics are governed by (4) the state is only observable through some function such that (5) , , mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset as shown in figure 1, the koopman operator is an infinite-dimensional linear operator acting on observing function such that (6) where is the composition operator. suppose that in some hilbert space spanned by a set of basis functions termed koopman eigenfunctions satisfying that (7) it follows that observing function can be compactly decomposed into (8) with the koopman mode being . as per (7), the evolution of the measurement dynamics can be presented as (9) which is referred as koopman mode decomposition and tightly connected to dmd. dmd is indeed a finite truncation of koopman mode decomposition for a linear system ( is a linear function) [28], [43]. figure 1: schematic of koopman operator theory. an observing function maps system states into a highdimensional space where measurements evolving linearly governed by koopman operator is usually nonlinear [43]. figure 2: schematics of deep koopman neural network. (a) shows an autoencoder and establishing a bijective static mapping between the original space and the high-dimensional linear space . (b) shows how the dknn performs one-step prediction. (c) interprets the loss function . the left panel corresponds to , while the right stands for . figure 3: dknn based anomaly detection protocol. left: svdd calculates the radius associated with 90% confidence interval based on the residues between predictions and measurements. right: an anomaly is detected , while the evolution operator of states mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset if the residue of a newly cast prediction is larger than an established radius. otherwise, the system is still working in normal. 3.3. deep koopman neural network kot is a seemingly elegant theory enabling global linearization but rather difficult to perform, as solving the triplet of the eigenfunction , the eigenvalue and the mode is a daunting task. the choice of eigenfunctions is non-trivial and calls for intricate tricks. in stark contrast, deep neural network provides a convenient way to seek the eigenfunctions. reference [33] reported a neat approach based on a deep autoencoder which constitutes a bijective mapping between the original space and the highdimensional linear space and approximates the set of the valid eigenfunction bases (see figure 2a). note that [33] needs an auxiliary neural network to perform the koopman operator, and it substantially increases the complexity. as such, we revise the neural network presented in [33] by removing the auxiliary neural network and identifying the linear operator directly, which is modeled by a linear network (see figure 2b). subsequently, we specify the loss function for the dknn training. the loss function is composed of five parts, the first three of which is specified as follows (10) here and represent the reconstruction error and one-step prediction error in the original space respectively, and is the one-step prediction error in the high-dimensional linear space (see figure 2c). the subscript mse stands for mean squared error. an term is also used to penalize the data point with the largest loss (11) additionally, regularization is imposed on the neural network weights to prevent overfitting (12) hence, the total loss function is the weighted summation of all the five parts (13) where for stands for the weight for each parts in the loss function. the dknn is then determined by solving the optimization problem . for sps process monitoring, the input can be the moments (mean, variance, etc.) of molecule counts of interest. 3.4. anomaly detection protocol with the dknn model well trained, it is possible to calculate the residues between the model predictions and measurements. given the residues yielded, the svdd is used to compute the 90% confidence threshold, which is termed as radius thereafter (see figure 3left). in practice, given the historical data, dknn casts one-step predictions, which are used to compute the residues. the yielded residues are compared with the radius obtained before. if a residue is larger than the radius, an anomaly is detected. otherwise, the system is still running normally (see figure 3right). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: stochastic simulations for example 1. figure 5: dknn process monitoring for example 1 based on mean-value data. (a) shows the dknn model based on mean-value data cast precise one-step predictions, as predictions (green dots) are close to the line (purple). (b) svdd calculates the radius (red) for anomaly detection and most samples (green dots) are contained within the radius. figure 6: sensitivity of moments against anomaly. the anomaly occurs at time . all the moments are normalized for visual convenience, and the normalization methods are stated in appendix 6.2. moments of order higher or equal to 2 are sensitive to anomaly, while the mean value is not. table 1: anomaly detection f-scores test result for mean-valued data of example 1. confidence 90% time (min) 401 420 450 480 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f-score (%) 15.365 11.645 14.155 12.744 figure 7: accuracy of dknn models one-step prediction for different orders of moments. dknn model trained on a dataset containing (a) mean and variance; (b) mean, variance and third-order moment; (c) mean, variance, third-order moment and fourth-order moment. figure 8: f-score of temporal anomaly detection of three dknn model trained on dataset containing moments of order up to 2, 3 and 4. 4. results next we unfold the process monitoring protocols on two canonical examples with both firmly rooted in sps. 4.1. example 1 the first canonical example considered comprises the following set of biochemical reactions: (14) where stands for a protein of interest. the first reaction in (14) in fact represent a group of reactions, and means that the protein is produced in bursts, whose size conforms to a geometric distribution parametrized by , while the second stands for the degradation of protein or its loss of functionality. the system (14) is known as bursty system in literature, and was found to adequately characterize the stochastic dynamics of most genes in mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mammalian or human cells [40]. the burst frequency is selected as 0.0282 min-1, the mean burst size is 3.46, and the degradation rate constant is 0.01 min-1. these kinetic parameters correspond to those associated with gene nanog in mouse embryonic stem cells [40]. we first simulate the system (14) by means of ssa for 1, 10, 100 and 1000 realizations and each for two sets. in either set, the protein numbers are averaged for all realizations at each time point. the results in figure 4 show that the single-realization data is remarkably noisy and thus poses challenges for establishing a robust process monitoring model (see figure 4a). the distribution of protein numbers at min is shown in figure 4e, and is indeed a negative binomial distribution [40]. the fluctuations are substantially attenuated as the number of averaged realizations increase (see figures. 4b, 4c, 4d). it suggests that ensemble method is a simple but effective approach for data curation. however, precautions should be taken for large number of realizations for two reasons: (i) the anomaly may be averaged out so that its detection becomes challenging; (ii) the large number of realizations is tantamount to that of cells, whose sampling may be difficult in practice. here we choose the number to be 100. next we show that the mean is not adequate for process monitoring on sps. to this end, we simulate a fault by decreasing to a third ( min-1) and increasing by three times ( ) at time . first, we trained a dknn model with mean values at two successive time points as input and output. the training dataset comprises 2000 data points collected at time corresponding to the steady state (see figure 4e), while a test set is of size 100, on which an accuracy test is performed. the accuracy of the trained dknn model is shown in figure 5a. the predictions are distributed close to the line , indicating that these predictions are accurate. by means of svdd, a radius for anomaly detection is computed and shown as red line in figure 5b. most of the residues (~ 90%) are contained within this radius. within the help of the dknn model and the radius, we perform the test to detect the aforementioned anomaly occurring at time . the f-scores averaged over 20 independent ensemble samples at 4 different time points are presented in table 1. it clearly shows that the detection accuracy is low and cannot be improved over time, thereby solidly advocating our statement that mean value is not sufficient for sps process monitoring. the unsatisfactory result is attributed to the anomaly we specially chose. as stated previously, the steady state distribution of the system (14) is negative binomial parametrized as with the mean being . the mean is not altered for the specially selected anomaly. hence, it is a vivid example showing that the mean value is not adequate to characterize the sps dynamics and calls for high-order moments. it is also evidenced by figure 6a that the difference between the faulted and normal trajectories can hardly be discerned, whereas figures. 6b, 6c, 6d show that high-order moments are much more sensitive to the anomalies. given the observation, it is necessary to incorporate high-order moments in datasets for sps anomaly detection. as such, we create another three pairs of training and test datasets, and each has the moments up to order 2, 3 and 4 respectively. the methods of moments calculation are stated in appendix 6.1. after training dknn models on the three training datasets, three independent accuracy tests on the corresponding test dataset are carried out, and the results are shown in figure 7. it shows that the accuracy degrades as the order of moment of prediction interest increases as expected. generally, the and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fluctuations in higher-order moments are more intense than that in lower-order moments. subsequently, we use the three well-trained dknn models to detect the aforementioned anomaly. it shows in figure 8 that the detection becomes more accurate as the anomaly effects accumulate in time. besides, the models based on moments of order 3 and order 4 outperform that of order 2, while the performance of the former two are comparable. hence, it is concluded that the combination of moments of order up to 3 probably suits best for dknn model performing anomaly detection in sps. furthermore, we compare the dknn model and dmd model both trained on the dataset containing moments of order up to 3. the accuracy comparison is summarized in figure 9a. it shows that dknn outperforms dmd on the predictions of all the moments. however, the dknn's advantage is mitigating as the stochasticity gets stronger in higher-order moment data. as for anomaly detection, the f-scores of dknn are higher than that of dmd by 15% ~ 50% (see figure 9b). figure 9: comparison of dknn and dmd on (a) prediction accuracy and (b) anomaly detection of example 1. figure 10: comparison of dknn and dmd on prediction accuracy of example 2. figure 11: stochastic simulations for example 2. table 2: comparision of dknn and dmd on detection of anomalies case 1 & case 2 in example 2 case case 1 case 2 method dknn dmd dknn dmd mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset time (min) 21 21 21 21 f-score (%) 92.44 66.67 23.91 16.39 table 3: dknn technical details case case 1 case 2 method dknn dmd dknn dmd time (min) 21 21 21 21 f-score (%) 92.44 66.67 23.91 16.39 4.2. example 2 next we consider a more complicated example, which is of great biological interest as well. the sps consists of five biochemical reactions: (15) the system as a whole is named telegraph model, which is a renowned model for gene expression in [44]. the symbols and stand for two gene states that are actively expressing proteins (usually referred as on state) and less active (referred as off state with leakage). the first two reactions in (15) mean protein being expressed, the third stands for protein degradation, the fourth and fifth mean that the gene is hopping between on and off states. the kinetic parameters we use here are: , , , , . by using ssa, we collect data at time min to create a training dataset of size 2000 and a test dataset of size 100. both datasets contain the moments of order up to 3. by training dknn and dmd model on the training dataset and comparing both on the test dataset, it is found in figure 10 that dknn is remarkably better than dmd for predicting all the moments, despite a loss in accuracy compared to the result of example 1. however, it is with expectation, since the distribution for the kinetic parameters selected is bimodal suggesting the protein number is fluctuating between two disparate levels (see figure 11). in the following, we further compare both models on detecting two different types of anomalies. 4.2.1. case 1 the rate is changed to 40 at time min, which corresponds to gene expression process of state on changed. based on the yielded models and the associated residues, svdd computes the radii of 90% confidence interval for anomaly detection. the detection result is reported in table 2, where the fscores strongly support the superiority of dknn. 4.2.2. case 2 the rate is changed to at time min, which corresponds the gene is more often switching to off state. by applying the same process monitoring protocol again, the results in table 2 again confirms dknn's supremacy against dmd. however, the f-scores are lower than that of case 1. it may be related to that case 2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset corresponds to a perturbation on the upstream of gene expression, while case 1 corresponds to the downstream. the upstream perturbation may be buffered by a multitude of downstream processes, and thus becomes more challenging to detect. nevertheless, case 2 provides an excellent arena for benchmarking various process monitoring methods. 5. conclusions in this paper, we discuss the process monitoring for sps and develop an integrated method of koopman operator theory and deep neural network to solve it. the method uses a deep autoencoder structure to establish a bijective mapping between original space and a high-dimensional linear space, where the koopman operator operates. an anomaly detection threshold is computed by svdd on the basis of unmodeled residues. it is also argued that given the novel type of stochasticity⁠—intrinsic noise, the sps in the form of biochemical systems simulated by ssa can serve as an excellent arena for benchmarking various process monitoring methods. as sps data is remarkably noisy, we propose to use ensemble method to tackle it and conclude that high-order moments have to be incorporated for robustness. 6. appendix 6.1. moment calculation the moments in data are calculated as central moments (16) where is the number of samples, stands for the value of sample at a certain time, and is the mean of sample. 6.2. moment normalization the moments in the normal case is normalized by the min-max method as follows (17) where is the raw moment data, stands for the normalized moment, and stand for the minimum and maximum of the raw data. the moments in the faulted case are normalized as per the minimum and maximum of the normal case. 6.3. neural network details the koopman operator is implemented as a linear network. all the technical details of dknn including network structure and hyperparameters are summarized in table 3. all the weights of neural network are initialized as per a truncated normal distribution , while the biases are set to 0. the training optimizer is adam with a learning rate equal to 0.001. references wang, g., haringa, c., noorman, h., chu, j., and zhuang, y. (2020). developing a computational framework to advance bioprocess scale-up. trends in biotechnology, 38(8), 846-856. , mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset lu, j., cao, z., zhao, c., and gao, f. (2019). 110th anniversary: an overview on learning-based model predictive control for batch processes. industrial & engineering chemistry research, 58(37), 1716417173. jiang, q., wang, z., yan, s., and cao, z. (2022). data-driven soft sensing for batch processes using neural network-based deep quality-relevant representation learning. ieee transactions on artificial intelligence. cao, z., yu, j., wang, w., lu, h., xia, x., xu, h., and zhang, l. (2020). multi-scale data-driven engineering for biosynthetic titer improvement. current opinion in biotechnology, 65, 205-212. [5] gao, j., feng, e., and zhang, w. (2022). modeling and parameter identification of microbial batch fermentation under environmental disturbances. applied mathematical modelling, 108, 205-219. soukoulis, c., panagiotidis, p., koureli, r., and tzia, c. (2007). industrial yogurt manufacture: monitoring of fermentation process and improvement of final product quality. journal of dairy science, 90(6), 26412654. sriramula, s., and chryssanthopoulos, m. k. (2009). quantification of uncertainty modelling in stochastic analysis of frp composites. composites part a: applied science and manufacturing, 40(11), 16731684. lu, h., plataniotis, k. n., and venetsanopoulos, a. n. (2008). mpca: multilinear principal component analysis of tensor objects. ieee transactions on neural networks, 19(1), 18-39. [9] lee, j. m., yoo, c., and lee, i. b. (2004). fault detection of batch processes using multiway kernel principal component analysis. computers & chemical engineering, 28(9), 1837-1847. jia, z. y., wang, p., and gao, x. j. (2012). process monitoring and fault diagnosis of penicillin fermentation based on improved mica. advanced materials research, 591, 1783-1788. zhao, c., gao, f., and wang, f. (2009). nonlinear batch process monitoring using phase-based kernelindependent component analysis−principal component analysis (kica−pca). industrial & engineering chemistry research, 48(20), 9163-9174. peng, c., chunhao, d., and qiankun, z. (2020). fault diagnosis of microbial pharmaceutical fermentation process with non-gaussian and nonlinear coexistence. chemometrics and intelligent laboratory systems, 199, 103931. yang, c., and hou, j. (2016). fed-batch fermentation penicillin process fault diagnosis and detection based on support vector machine. neurocomputing, 190, 117-123. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ding, j., cao, y., mpofu, e., and shi, z. (2012). a hybrid support vector machine and fuzzy reasoning based fault diagnosis and rescue system for stable glutamate fermentation. chemical engineering research and design, 90(9), 1197-1207. hornik, k., stinchcombe, m., and white, h. (1989). multilayer feedforward networks are universal approximators. neural networks, 2(5), 359-366. shimizu, h., yasuoka, k., uchiyama, k., and shioya, s. (1997). on-line fault diagnosis for optimal rice aamylase production process of a temperature-sensitive mutant of saccharomyces cerevisiae by an autoassociative neural network. journal of fermentation and bioengineering, 83(5), 435-442. lopes, j. a., and menezes, j. c. (2004). multivariate monitoring of fermentation processes with non-linear modelling methods. analytica chimica acta, 515(1), 101-108. yu, j., zhang, c., and wang, s. (2021). multichannel one-dimensional convolutional neural network-based feature learning for fault diagnosis of industrial processes. neural computing and applications, 33, 3085-3104. chen, s., yu, j., and wang, s. (2020). one-dimensional convolutional auto-encoder-based feature learning for fault diagnosis of multivariate processes. journal of process control, 87, 54-67. [20] peng, c., lu, r., kang, o., and kai, w. (2020). batch process fault detection for multi-stage broad learning system. neural networks, 129, 298-312. chen, h., liu, z., alippi, c., huang, b., and liu, d. (2022). explainable intelligent fault diagnosis for nonlinear dynamic systems: from unsupervised to supervised learning. ieee transactions on neural networks and learning systems. chen, h., chai, z., dogru, o., jiang, b., and huang, b. (2021). data-driven designs of fault detection systems via neural network-aided learning. ieee transactions on neural networks and learning systems, 33(10), 5694-5705. sherstinsky, a. (2020). fundamentals of recurrent neural network (rnn) and long short-term memory (lstm) network. physica d: nonlinear phenomena, 404, 132306. zhang, m., li, x., and wang, r. (2021). incipient fault diagnosis of batch process based on deep time series feature extraction. arabian journal for science and engineering, 1-12. ren, j., and ni, d. (2020). a batch-wise lstm-encoder decoder network for batch process monitoring. chemical engineering research and design, 164, 102-112. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset koopman, b. o. (1931). hamiltonian systems and transformation in hilbert space. proceedings of the national academy of sciences, 17(5), 315-318. brunton, s. l. (2019). notes on koopman operator theory. universität von washington, department of mechanical engineering, zugriff, 30. rowley, c. w., mezić, i., bagheri, s., schlatter, p., and henningson, d. s. (2009). spectral analysis of nonlinear flows. journal of fluid mechanics, 641, 115-127. schmid, p. j. (2010). dynamic mode decomposition of numerical and experimental data. journal of fluid mechanics, 656, 5-28. williams, m. o., kevrekidis, i. g., and rowley, c. w. (2015). a data–driven approximation of the koopman operator: extending dynamic mode decomposition. journal of nonlinear science, 25, 13071346. korda, m., and mezić, i. (2018). linear predictors for nonlinear dynamical systems: koopman operator meets model predictive control. automatica, 93, 149-160. brunton, s. l., brunton, b. w., proctor, j. l., and kutz, j. n. (2016). koopman invariant subspaces and finite linear representations of nonlinear dynamical systems for control. plos one, 11(2), e0150171. lusch, b., kutz, j. n., and brunton, s. l. (2018). deep learning for universal linear embeddings of nonlinear dynamics. nature communications, 9(1), 4950. yeung, e., kundu, s., and hodas, n. (2019, july). learning deep neural network representations for koopman operators of nonlinear dynamical systems. in 2019 american control conference (acc) (pp. 48324839). ieee. dubey, r., samantaray, s. r., panigrahi, b. k., and venkoparao, v. g. (2016). koopman analysis based widearea back-up protection and faulted line identification for series-compensated power network. ieee systems journal, 12(3), 2634-2644. dang, z., lv, y., li, y., and wei, g. (2018). improved dynamic mode decomposition and its application to fault diagnosis of rolling bearing. sensors, 18(6), 1972. cheng, c., ding, j., and zhang, y. (2020). a koopman operator approach for machinery health monitoring and prediction with noisy and low-dimensional industrial time series. neurocomputing, 406, 204-214. liu, b., xiao, y., cao, l., hao, z., and deng, f. (2013). svdd-based outlier detection on uncertain data. knowledge and information systems, 34, 597-618. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 1; january febuary 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset larsson, a. j., johnsson, p., hagemann-jensen, m., hartmanis, l., faridani, o. r., reinius, b., and sandberg, r. (2019). genomic encoding of transcriptional burst kinetics. nature, 565(7738), 251254. cao, z., and grima, r. (2020). analytical distributions for detailed models of stochastic gene expression in eukaryotic cells. proceedings of the national academy of sciences, 117(9), 4682-4692. [41] gillespie, d. t. (1977). exact stochastic simulation of coupled chemical reactions. the journal of physical chemistry, 81(25), 2340-2361. fu, x., zhou, x., gu, d., cao, z., and grima, r. (2022). delayssatoolkit. jl: stochastic simulation of reaction systems with time delays in julia. bioinformatics, 38(17), 4243-4245. brunton, s. l., budišić, m., kaiser, e., and kutz, j. n. (2021). modern koopman theory for dynamical systems. arxiv preprint arxiv:2102.12086. cao, z., and grima, r. (2018). linear mapping approximation of gene regulatory networks with stochastic dynamics. nature communications, 9(1), 3305. mailto:topacademicjournals@gmail.com 060210-f538-fap-521689-academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a comparative study of loader shovelling mechanisms with discrete unit modeling mei ying wang, jian hong liu and xin wei zhao school of intelligent engineering, jinzhong college of information, jinzhong, 030800, china abstract: loader shovelling mechanisms are used in various industrial applications, and the resistance encountered during the shovel loading process greatly affects the loading efficiency. shovel loading resistance is the reaction force of the material on the bucket during the shovel loading process and contains two parts: the resistance of the bucket insertion stage and the resistance of the lifting stage. therefore, it is essential to conduct research on shovel loading resistance to improve the performance of the loader shovelling mechanism. this paper presents a simulation analysis of the loader shovelling mechanism using the discrete element theory and edem software. a simulation model of the loading process is established, and the forward and reverse shovel loading processes are simulated. the mechanical characteristics of the shovelling operation are analysed visually, and the obstructing effect of the material on the bucket is clarified. the shovelling resistance of the key parts of the bucket at different stages of the shovelling process is specifically analysed, and the parts where the peak shovelling resistance is located and the stages where it is located are identified. the influence of the shovel angle on the resistance is also analysed. the results of the simulation analysis provide insight into the shovel loading resistance and the performance of the loader shovelling mechanism. the study demonstrates that the discrete element method can be effectively used in the simulation analysis of loader shovelling mechanisms, providing a useful tool for the design and optimisation of the loader shovelling mechanism. in conclusion, this research sheds light on the important mechanical characteristics of the shovel loading process and provides a comprehensive analysis of the shovelling resistance encountered by the loader shovelling mechanism. the results of this study can be applied to improve the design and performance of the loader shovelling mechanism, which can have a positive impact on various industrial applications that rely on this technology. keywords: shovel loading resistance, discrete element theory, edem software, simulation model, loading efficiency, mechanical characteristics, obstructing effect, peak shovelling resistance, shovel angle. 1. introduction the discrete unit method is to view the medium as a set of discrete independent moving units and to build a mathematical model through the properties of the discrete body, treating the object of analysis as a discrete particle, which corresponds to the properties of the discrete body itself. edem software is based on the discrete unit method and is widely used in many fields to calculate simulation processes quickly and efficiently. the software allows detailed analysis of the simulation results, such as graph types, particle tracking, transient analysis, etc. yang study loader shovelling mechanisms. includes the shovelling operation process and the mailto:topacademicjournals@gmail.com https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav77oq0bsntxyki_fpuey0ory1srzjf6gzzawscnovv0zyn5hf0vsyinzepdhwjqi_y0nhju_gob74glafldonvczkqsqxly5fy=&uniplatform=nzkpt academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset theoretical basis[1]. based on the discrete element principle, pang lizhi studied the bucket wheel pick-up process. taking the pick-up machine of a power plant as the research object, he applied edem software to simulate the horizontal pick-up process[2]. wang proposed the use of recurdyn to construct the loader model, and the use of edem to construct the material model, and carried out the coupling simulation analysis of recurdyn-edem to study the coupling effect between the loader working device and the material under different trajectories[3]. zheng according to the collapsed material working conditions occurring in the actual operation of the material extractor, the bucket wheel excavation edem simulation model was established by studying the bucket wheel three-dimensional model, combined with the discrete unit method; the time course curves of the excavation resistance of multiple buckets in the material collapse process, under different deep burial conditions and in different directions were calculated, and the calculated values of the bucket wheel excavation resistance in the design specification were compared to assess the hazards of the maximum excavation resistance under different deep burial conditions[4]. li through data processing and setting of simulation parameters, a shovel loading model was established in edem software for shovel excavation conditions, and the accuracy of the model was verified by experimental and simulation methods; afterwards, the shovel loading process was simulated, and the resistance of different parts of the bucket at different stages of shovel loading was analysed to find out where the peak of shovel loading resistance was located[5].the characteristics of the bulk material and the loading conditions of the loader were analyzed by yu, the characteristics of the rock material were introduced, the calculation methods for calculating the operating resistance were summarized, and the factors influencing the size of the loading resistance were classified in the shovelling process, and the main factors were grasped for analysis [6]. 2. bucket model the bucket is an important actuator for loading, transporting and discharging materials in the loader's working equipment. it is usually made of the front edge (sometimes equipped with bucket teeth), the bottom of the bucket, the circular bucket wall, the side edge, the side wall and the rear baffle welded together, and the shape in the transverse direction of the body remains basically unchanged, so the geometry of the bucket is determined by the longitudinal section size. at present, the bucket radius of gyration r is usually used as the basic parameter for the calculation of other parameters in the design, with the following formula. r= (1) r: bucket radius of rotation/m; vs : bucket flat capacity/m3 ; b0 : bucket internal measured width/m; λg : bucket bottom length coefficient; λz : back wall length coefficient; λk : baffle height coefficient; λr : radius of circle coefficient; γ: opening angle; γ1 : angle between baffle and back wall bulk materials consist of dispersed particles with a bulk substance that is not normally found in solids, liquids and gases, and whose garments of motion follow newton's second law [7]. under the action of internal forces, the particles of an object device undergo some kind of flow and take on the characteristics of a liquid, eventually forming a particle flow. in our daily life there are mainly gravel, sand, coal and grains, of which gravel, sand and [ ] − − − + ) 180 0.5(1 2 cos 0.5 cos 2 1 k 0 γ π γ λλγλ r z s b v mailto:topacademicjournals@gmail.com https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav5q_fe6vsc70eilciz6brgrqashumde22trzz6vjotpjwedppuycintfvytu30dhkqlxtynteofkitgiwtna7lxgtnavhzsnhe=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav6wx5ktkniv0sp4dxvxkr11jfybktscbdfadtylqcucg4tfzhubh8-tqk6t7vcasopihblcrae-ikpb8_bmq3wzxn3-ii9e960=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav6wx5ktkniv0sp4dxvxkr11jfybktscbdfadtylqcucg4tfzhubh8-tqk6t7vcasopihblcrae-ikpb8_bmq3wzxn3-ii9e960=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav6wx5ktkniv0sp4dxvxkr11jfybktscbdfadtylqcucg4tfzhubh8-tqk6t7vcasopihblcrae-ikpb8_bmq3wzxn3-ii9e960=&uniplatform=nzkpt https://kns.cnki.net/kcms2/author/detail?v=zhhslvpvav65l8icod58aicipvz23ssvkiy4rbjf3tut-gzjgdmtc15azkfaicqdkti_rj2bvm65ioatw30bce94wdnc5mxwgf-edugcen0=&uniplatform=nzkpt academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset coal are of most interest. the general rock materials are granite, limestone, sandstone, shale, etc. the characteristic features are different and table 1 shows the relevant physical properties of crushed rock [8]. table 1: physical properties of aggregates properties numerical values properties numerical values modulus of elasticity e 1.5 x 108 n/m2 resistance factor 0.20 density 1.9 x 103 kg/m3 coefficient ostatic friction 0.90 friction angle 32.5° rolling friction coefficient 0.66 poisson's ratio 0.35 3. non-adhesive spherical particle contact forces (hertz theory) the contact model is an important basis for modelling the discrete element method, its description of the contact behaviour between elements and the analytical calculations directly determine the magnitude of the forces and moments applied to the particles. therefore when using the discrete element method for different objects, the contact models differ and the results vary, but all simulation models must include at least one basic particle-toparticle and particle-to-geometry boundary contact model [9-12]. in this paper, in order to simplify the simulation, the default contact model hertz theory model set in the edem software is used uniformly, which has an efficient and accurate computational performance. hertz contact theory assumes that the surfaces of particles in contact with each other are smooth and homogeneous, that the contact surface is small compared to the particle surface, that only elastic deformation occurs at the contact surface, and that the contact force is perpendicular to the contact surface [13-14]. the hertz contact theory is the theoretical basis of the problem and is applicable to the elastic contact of curved bodies such as spheres, columns and ellipsoids, and even to the contact of micro-convex bodies between contact surfaces. as shown in fig.1, two spherical particles of radii r1 and r2 are in elastic contact, and the normal overlap α is α = r1 + r2 -|r1 -r2 |>0 (2) the radii of particle 1 and particle 2 are r1 , r2; r1 and r2 are the spherical position vectors of the two particles respectively. the dotted line in figure 1 shows the location of the particle surface when no deformation is considered, and the contact surface between the particles is circular, then the contact surface radius a is: a= ar* (3) the inter-particle normal forces n are: 1 3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset n=e r*( *) 2α 2 (4) r* and e* are the effective particle radius and effective modulus of elasticity respectively. 1 1 1 = + (5) r* r r1 2 1 1−ν12 1−ν22 = + (6) e* e1 e2 e1,v1,e2,v2 are the modulus of elasticity and poisson's ratio of particle 1 and particle 2, respectively. when the increment of overlap between two contacting particles is δα, the increment of normal force δn is calculated from (4) or (5). ∆ =n 2 αr e* *∆ =α 2a *e ∆α (7) 4. analysis of forward shovelling resistance 4.1 forces on the bucket in the x, y and z directions the forces on the bucket in the x, y and z directions are first analysed. in the simulation, a certain number of gravel particles are loaded into the bucket. the bucket is first shovelled into the rubble pile and then the bucket filled with rubble leaves the pile. the software offers linear translational rotation, sinusoidal translational rotation and convey or translational rotation. therefore, here we use linear translation and rotation. first, the bucket is shovelled parallel into the pile to a certain depth, then the bucket is turned over and lifted up. figures 2, 3, 4 and 5 show the variation of forces in the x,y and z directions versus time. where the full shovelling process is 15s. the horizontal axis represents the time of shovelling and the vertical axis represents the amount of shovelling resistance applied in each direction. figure 1: particle contact deformation diagram figure 2: shovel loading simulation analysis of figure 3 shows that the resistance of the bucket in the x-axis direction exceeds 9kn when the bucket is just shovelling into the rubble pile, there are small fluctuations in the resistance during the process of shovelling into the rubble, but when the bucket is filled with rubble the resistance rises rapidly to 12kn when the bucket is turned over and lifted off the pile, then the maximum partial force falls rapidly to the lowest resistance corresponding to the bucket shovelling out of the rubble pile. the x-directional force then does not change much. the peak force is generated in approximately 1.5s. 2 a a mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: x-directional component of shovel loading resistance the peak force is approximately 1.5 s. the corresponding force in the z-axis in figure 5 is not very large compared to the x and y-axis. y-axis is not very large. the rest of the time is very smooth. the z-directional force is much smaller than the xand y-directions. 2 5 8 time/s 12 11 10 9 2 5 8 time/s -8 -9 -10 -11 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: y-direction of the shovel load resistance figure 5: z-directional component of shovel loading resistance 4.2 force analysis of the bucket base plate as the forces exerted on the base plate are the greatest during the shovelling process, the next discussion will focus on the base plate and the left and right plates of the bucket will not be analysed for the time being. simplifying the actual shovelling process of the loader, the shovel-in phase lasts 7 seconds and the bucket speed is 0.2 m/s; the effective working phase lasts 4 seconds and the angular speed of the bucket is 0.15 arc/s. the forces exerted by the material on the bucket floor during the horizontal shovel-in phase are shown in figure 6. the forces exerted by the material on the bucket during the bucket reversal lift are shown in figure 7. 3 5 7 time/s 3.5 3 2.5 2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6: bucket forces in the horizontal shovel-in phase figure 7: bucket stress diagram in lifting phase the analysis of the shovel loading resistance during the horizontal insertion phase showed that during the horizontal insertion phase the total force at the bottom first increased, then decreased and finally stabilised, with local fluctuations during which it showed a secondary peak. the maximum force was 3.5 kn. in the subsequent stages, the force gradually stabilised when the amount of material loaded reached a threshold. as the bucket rotates upwards, the forces previously concentrated at the bottom of the bucket are gradually transferred to the circular wall of the bucket during this phase, so that the forces acting on the bottom of the bucket are significantly reduced during this phase. 5. results of reverse shovel analysis 5.1 forces on the bucket in the x, y and z directions figures 8, 9 and 10 show the relationship between the total force applied to the bucket during excavation in the x, y and z directions as a function of time. where the full shovelling process is 14s. where the horizontal axis indicates the digging time and the vertical axis indicates the magnitude of the digging resistance applied in each direction. 7 9 11 time/s 2 1.5 1 0.5 3 9 6 time/s 10 9 8 7 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 8: x-directional component of the digging resistance the relationship between the x-directional force and time can be seen in figure 8. the resistance of the bucket in the x-direction was just over 7kn when the bucket was just shovelling into the rubble pile, and its x-directional force reached its maximum value of 9.8kn around the 8th s. between 5.5s and 8s, the bucket force had a more obvious fluctuation. as the time increases, its digging resistance gradually decreases, and after 9s its resistance drops significantly. figure 9: the y-directional component of the digging resistance figure 10: z-directional component of the digging resistance from the results of the y-axis force splitting simulated in figure 9, it can be seen that the bucket's force splitting decreases gradually from 3 to 7.5s, reaching a minimum of -25kn, and gradually increases after 7.5s. after 6s, the force varies considerably, especially between 7 and 7.5s, when the trend of force decrease is extremely obvious. 3 6 9 time/s -10 20 15 -25 3 6 9 time/s 32 24 16 8 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the results of the z-directional forces simulated in figure 10 show that the bucket's digging resistance gradually tends to increase from 3s onwards, reaching a peak of 32kn at around 5s, and then showing a decline to a minimum of 8kn at the initial resistance. 5.2 force analysis of the bucket base plate the following analysis of the horizontal insertion phase of the excavation resistance analysis, in edem derived from the bucket bottom part in the horizontal insertion phase of the force diagram as figure 11, horizontal insertion phase, the bucket bottom overall force first increase and then decrease, local fluctuations. in the later stages, the forces are gradually stabilised as the amount of excavated material has reached its limit. as the bucket is turned upwards, the bucket floor, which previously bore the main part, is gradually shifted to the circular wall at this stage, so that the forces on the floor at this stage are on a decreasing trend, as shown in figure 12. figure 11: bucket forces in the horizontal insertion phase figure 12: bucket forces during the pick-up phase 6. effect of shovel entry angle on resistance when shovelling horizontally, the bucket is shovelled into the rubble pile at a natural horizontal ground level, but due to the influence of the front teeth of the bucket, the bottom plate of the bucket is tilted at a certain angle to 10 12 14 time/ 12 11 10 9 3 6 9 time/ 24 18 12 6 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the horizontal surface and cannot achieve true horizontal; while shovelling into the rubble pile at a certain angle, the bottom plate of the bucket must be at a certain angle to the horizontal surface. when the shovel entry angle is less than 11°, the simulation result is close to the calculated value. in particular, when the shovel entry angle is between 5° and 10°, the two almost coincide. therefore, we analytically derived the process of shovelling the bucket into the rubble pile, where 7° and 9° were targeted, in order to obtain the best insertion angle. as shown in figure 13, it is concluded that the shovel entry resistance increases with increasing shovel entry depth, and with increasing shovel entry angle. when the shovel penetration depth is 0.3 m, the effect of the shovel penetration angle on the shovel penetration resistance is relatively small; when the shovel penetration depth exceeds 0.5 m, there is a significant increase in the shovel penetration resistance. figure 13: resistance variation curve 7. conclusion based on the discrete element theory, this paper applies edem software to establish a simulation model of the loading process and realise the simulation of the forward and reverse shovelling operation process. through the simulation, the shovel resistance of different parts of the bucket at different stages of the shovel loading process is analysed, and the parts where the peak shovel resistance is located and the stages where it is located are identified. the resistance of the bucket in the x, y and z directions was analysed in the forward and reverse shovelling process. according to the force analysis of the bucket, the force on the bucket floor is the largest, after which the force analysis of the bucket floor during forward and reverse shovelling was carried out to obtain the trend of force changes. finally, the influence of the shovel entry angle on the resistance was analysed. it can be seen that when the shovel entry angle is 9°, the resistance increases with the depth of shovel entry. acknowledgements this paper was supported by①“2022 science and technology innovation project for higher education institutions in shanxi province (2022l659)”②“2022 innovation and entrepreneurship project for students in shanxi province(20221640)” references yang zikang. research on resistance reduction shoveling strategy of loader based on edem [d]. jilin university, 2022. 2 1.5 1 0.5 bucket penetration 0.2 0.4 0.6 shovel-in angle 7° shovel-in angle 9° mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset pang, l. c.. research on the bucket-material interaction mechanism of bucket wheel stacker bucket based on discrete element method [d]. jilin university, 2022. wang shaojie, yin yue, yu shengfeng, hou liang. simulation analysis of loader coupling dynamics based on recurdyn-edem [j]. machine design,2021,38(11):1-6. zheng pei, song wenxi, hu xiong. edem simulation of excavation resistance of bucket wheel stacker reclaimer under collapsed material condition [j]. sintered pellets, 2019,44(06):50-54. [5] li r, xu wubin, li bing, yang xu. research on discrete unit method for bucket shovel resistance of loader [j]. journal of guangxi university of science and technology,2017,28(03):77-82. yu, xuebang. simulation study of loader bucket operation resistance based on edem [d]. guangxi university of science and technology, 2018. seife c. can the laws of physics be unified? science,2005,309(5731): 82-82. yan bo, zhan kai, guo xin, li hengtong, shi xiaojie. simulation study of underground scraper shoveling process based on edem [j]. nonferrous metals (mining part),2019, 71(06):74-77. [9] sun qc, wang gq. introduction to the mechanics of particulate matter. beijing:science press, 2009. sun qicheng, hou meiying, jin feng. physics and mechanics of particulate matter. beijing: science press, 2011. jaeger hm, nagel sr, behringer rp. granular solids, liquids, and gases. reu modern phgs, 1996, 68(4): 125912734. kadanoff lp. built upon sand: theoretical ideas inspiredby granular flows. rev modern phys, 1999, 71(1): 4354445. de gennes pg. granular matter: a tentative view.revmodern phys, 1999, 71(2): s374-s382. [14] forterre y, pouliquen o. flows of dense granular media.annual review flauid mechanics, 2008, 40: 1-26. mailto:topacademicjournals@gmail.com beginning at a very young age, today’s students are schooled at home (and just about everywhere else) by television academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the future of low speed scrubbing technology alexander michael brown department of chemical engineering, university of california, berkeley, ca, usa. abstract: low speed scrubbing technology (lsst) is a new technology for the purification of industrial exhausts from both gaseous and solid pollutants. it does not belong to either a counter-flow or co-flow system, but is based on the idea of regime change. the lsst scrubber, known as the low speed absorber (lsa), is free of any mechanical or pressure loads, has low hydraulic resistance, and has no unreliable structural units. it is a foolproof and serviceable construction. keywords: low speed scrubbing technology (lsst), low speed absorber (lsa), gas-liquid interaction, sorption, chemisorption, wet scrubber, absorber, counter-flow, co-flow, regime change introduction non-catalytic sorption/chemisorptions as a whole, including gas-liquid interaction in particular, is conceptually a phenomenon of a physico-chemical nature. it consists of the physical process of gas dilution in the liquid phase followed by a chemical interaction. these processes are well understood1-5. theory and design principles permit rate (efficiency) and limits of the sorption depending on both physico-chemical parameters of the process and engineering design to be quickly and reliably estimated. in engineering, these processes are usually done in units known as wet-scrubbers (or absorbers), the scrubbing process (i.e., gas/liquid interaction) proceeding as either a counter-flow or co-flow regime. in addition to the conventional co/counter-flow technologies, low speed scrubbing technology (lsst) is intended for the purification of industrial exhausts from both gaseous and solid (dust) pollutants6,7. it does not belong to either a counter-flow or co-flow system, but is based on the idea of regime change8-12. for practical embodiment, a scrubber of special design known as low speed absorber (lsa) is required. to gain an insight into both the theoretical basis and to design features of this technology, it is useful to follow a process in the simplest one-stage lsa. general description one-stage lsa conceptually consists of the contacting chamber, separation chamber, fixed (immovable) centrifugal separator, and various hydraulic units (fig. 1) and functions as follows. the initial contaminated gas enters the contacting chamber from the bottom upward and starts to ascend. at this stage it meets a liquid jet descending via back-pipes from the separation chamber joined from above. initially, the discharge liquid jet is compact. then it simultaneously starts to fall under gravity and break down into smaller fragments (regular and irregular drops) on exposure to the ascending gas. as this takes place, the small drops (i.e., with weights smaller than the dynamic pressure of the ascending gas) are instantly picked up by the ascending gas and start to ascend jointly with the gas. the heavier drops continue to descent and split mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset concurrently, thus regenerating both small and large drops. eventually, spontaneous self-fragmentation terminates. aerosols result from this process and continue to fall until retarding forces become initially equal to gravity and then more than gravity for any liquid fragment. from this point on, the dispersed liquid phase starts to ascend. figure. 1. schematic diagram of one-stage low speed absorber (lsa). this aerosol leaves the contacting chamber and enters the fixed centrifugal separator of the separation chamber located above. welded curvilinear blades of the fixed centrifugal separator direct haze onto the wall of the separation chamber. here actual phase separation occurs: the gas exits into the atmosphere as the cleaned exhaust, while the liquid flows down the wall and accumulates at the bottom of the separation chamber. then the densest portion (i.e., lower layers of the liquid) is drained via a drainage outlet, while the most aerated portion (i.e., upper layers) is partially recycled under gravity via back-pipes to the contacting chamber. in this way, there is an inner automatic recycling of the liquid phase between the contacting and separation chambers. its special feature lies in the fact that the times of phase contact relative to gas and liquid are dependent on different factors and hence can be controlled independently. contact time on the gas side is completely mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset predetermined by the gas speed, while contact time on the liquid side depends on the gas speed and the regime of liquid phase renewal (i.e. ratio of the feed and drained liquid fluxes). the latter, in turn, is a function of the current physico-chemical properties of the liquid and dispatch state. contact time on the liquid side is evidently unlimited and should be set accordingly to the efficiency of mass exchange by means of the variation of liquid phase renewal. hence, control valves of feed liquid and drainage can vary the contact time from the liquid side independently and simply. by and large, this provides high flexibility of the practical control of lsa operation. a point of any scrubbing technology is to mix the gas and liquid phases as well as possible. diverse conventional devices (e.g., packings, mechanical agitators, or mixers, as well as injectors, nozzles, etc.) are designed for suitable solution of the mixing problem. lsst has no need for any man-made mixing device because it is the counteraction between inertia forces of the ascending gas and the gravity forces of the descending liquid that triggers self-fragmentation and acts as a natural stirrer. this “stirrer” is uniformly distributed over the whole volume; it affects all spatial points of the contacting chamber. therefore, the back-pipes connecting the separation and contacting chambers are standard tubes rather than some specific injectors. the mode of operation (continuous, periodical, etc.) of drainage and supply of feed liquid, as well as the amount of the recycling liquid, is dictated by both sorption features and liquid properties. it facilitates easy remote control through the control valves. in this way, the low speed scrubbing process begins as a counter-flow while it terminates as a co-flow. theoretical fundamentals the most general equation of unsteady heat/mass exchange between the gas and dispersed liquid phase is of the form 1 c 1 2c 1 (c, ) 2 g ped s ( , ) ( 1 ) are dimensionless co-ordinates, gs={ g ,g ,g } 0 is the metric tensor. leaving aside here , , any details of formal transformation, eq. (1) can be eventually reduced1,13,14 to the well-known equation of unsteady diffusion as follows: c d c x x ( 2 ) the solution of eq. (2) depends on the nature of transfer processes, reciprocity of transfer phenomena and chemical processes, as well as initial and boundary conditions. in the approximation of the diffusion boundary layer, these items are usually considered with the help of similarity criteria in the following way: nud = f (re, ped, sc, fr) ( 3 ) re lu , ped lu , prd(sc) , fr u2 d d gl mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset physically, these determining criteria consider the nature of gas flow (reynolds number re), the interdependence of convection and diffusion transfer (peclet number ped), the similarity of the speed and concentration fields (either schmidt number sc or prandtl number for diffusion prd), and scale factor (froude number fr). the most comprehensive theoretical analysis of various specific cases (e.g., stokes regime/potential flow, laminar/turbulent motion, small/large pe-criteria, surface/volume chemical reaction) can be found in gupalo et al 6. practical use of similarity theory requires knowledge of both hydro/gas-dynamics essentials and numerical values of parameters as initial and boundary conditions (i.e., design features). the former can be revealed by pure analysis, while the latter are only experimentally determined. hydro/gas-dynamics as can be seen from above, lsst possesses specific hydro/gas-dynamics. compared to conventional co/counterflow systems, the essentials of lsst hydro/gas-dynamics can be explained as follows. to provide a stable lsst regime, the counteraction between inertial forces of the ascending gas and gravity forces fn of the descending liquid takes place under prevalence of the former relative to the drop of any r-size. the fall rate of the very large drops r >r>rsf (compact liquid jet r and the boundary of self-fragmentation rsf are the limits) is independent of the drop weight and size while solely is dependent on gravity fn ~ (mg)l ~(4/3) gr3 ( 4 ) at the same time, the fall rate of the smaller drops r<rsf is essentially dependent on their size. any r-drop maintains its integrity until consolidating forces (surface tension fs) fs ~ r ( 5 ) exceed breaking forces of resistance to the motion, the latter being a function of the motion regime and size of drop re ul recr laminar flow ( 6 ) recr turbulent flow for the turbulent flow around a small sphere r~10-6 m, local recr~10, while resistance forces ft are proportional to the drag force of the gas and the drop size ft ~ ( u2)gas r 2 ( 7 ) the comparison of fs and ft (eq. 5, 7) shows that the upper limit of fragmentation is non-existent, i.e., the breaking forces prevail over the consolidating ones under all conditions, including the limit r of compact liquid jet. physically, this means that any free-falling compact liquid jet disintegrates inevitably sooner or later. spontaneous self-fragmentation terminates at the point when the velocity head of the ascending gas becomes equal to the forces that determine both the scale and integrity of the drop (i.e., surface tension). thus, the lower limit of selffragmentation is dictated by their equality fs ~ ft rsf u2 ( 8 ) hence, rsf is dependent on the gas speed. it is easy to see that for pure water ( 1000 kg/m3, 75 65 kg/s2, 75 3.8.10-4 kg/m.s) and typical lsst regimes u~(10-20) m/s, the average size distribution lies mainly within the range rsf ~(100-500).10-6 m. redistribution of size grading in the domain located below the level of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset backpipes is governed by the scrubbing speed and properties of the liquid phase. specifically, the surviving drops rsf>r>r1 maintain their integrity and continue to fall in the turbulent regime as long as the condition re>recr of eq. (6) remains valid. finer drops r1>r>r2 fit the condition re<recr of eq. (6) and fall in the laminar regime. they are exposed to the breaking forces of the conventional gas-dynamic (stokes) nature 6 ru 6 ru (1 /r) fst= ( 9 ) as follows from eq. (4, 9), limiting r1-values fall in the range r1~ (50-100).10-6 m for typical lsst gas speeds u~(10-20) m/s. finally, the finest drops r<r2 maintain their integrity while never falling. once generated, they are immediately carried by the ascending gas into the separation chamber. the main feature of their motion lies in the fact that their absolute velocity is equal to the velocity of the gas carrier. in other words, the relative velocity of their motion equals zero. thus, collisions rarely occur and this finest fraction survives up to the final exhaust (unless special measures are implemented). the upper limit r2 is dependent on scale height of the medium h=kt/mg and for the limiting case of free fall, it can be estimated as 2 1/7 kt r2 3l g2 10-6 m. thus, the hydro/gas-dynamic pattern of disintegration can be generalized as follows: r >r>rsf -free (newton) fall, progressive self-fragmentation, settling rate is independent of drop size, rsf>r>r1 turbulent motion, partial fragmentation of the coarsest portion of aerosols is admissible, settling rate depends on drop size as u~r1/2, r1>r>r2 laminar (stokes) motion, no fragmentation, settling rate depends on drop size as u~r2, r2>r forced ascent (no fall), neither fragmentation nor drop growth occurs. the zone of self-fragmentation (domain between the level of the back-pipes and lower spatial boundary of aerosol) contains a very wide spectrum of drops r2<r<r . at the same time, the domain located above the level of the back-pipes contains finer aerosol r2<r<rsf (thin haze), i.e., this zone is far more uniform in the sense of size distribution. so far only destruction has been considered. various transfer effects (e.g., gravity, diffusion, convection) lead to collisions followed by coagulation of drops resulting in their growth 15. physically, the upper limit of this growth is evident, since any newly formed drop rnew to be smaller than the limiting values rsf, r1, r2 along the whole associated range of physical conditions. otherwise, if such drop rnew> rsf, r1, r2 is generated, then it will be destroyed again. the growth of any drop r( ) along the fall distance dz=ud depends on both number of collisions and liquidwater content gl kg/m3. for free fall, the relation between current mass dm of some r-drop and motion parameters mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 g lr4 gl 2dr ~ gl r2dz ~ gl r2ud ~ 9 d ( 10 ) dm ~ (4/3) inir allows for simple estimation of both dynamics of drop growth (terms 2 and 3) dr gl ~ dz 4 l ( 11 ) and fall time considers this growth (terms 2 and 5 of eq. (10)) 18 ggl rini ( 12 ) f eq. (11) shows that the drop growth is independent of the motion regime, while eq. (12) demonstrates that the fall time is independent of the final drop size (since the latter does not appear in eq. (12)), being dependent only on the initial size rini. eventually, the gravity force acting on any drop becomes less than the force of tractive resistance resulting in the termination of the fall. from this point on, the ascending gas selects and includes all liquid drops. the bottom spatial boundary of the fall distance represents the separation line between the domain of the incoming gas and the self-fragmentation zone, while the top boundary (i.e., back-pipes level) is the separation line between the self-fragmentation zone and the fine aerosols. above the level of the back-pipes, any small object r2 r rsf (no matter whether liquid or solid) acquires the velocity of the gas carrier. thus, the consideration of coagulation has a marginal effect on the general pattern. at the same time, it is relevant in relation to the current value of the interfacial area and intensity of heat/mass exchange between the gas carrier and the dispersed liquid phase. the collision of drops results in size redistribution during counter-way traffic of large (falling) drops and small (ascending) droplets, i.e., along the entire length of fall distance z. interaction of the ascending and descending dispersed objects is extremely favourable. in gas dynamics terms15, it increases residence time life. but more significantly, it enforces the sorption because of the continuous renewal of the interfacial area. both of these factors considerably improve the mass exchange coefficient , the latter being the most important generalised index of the sorption efficiency4,13,16. as is evident, self-fragmentation time, fall time, residence time and fall distance lie in averaged ranges sf~[(2/104) lrinirf)] 1/2~(0.05-0.20) s, f~(0.3-1.0) s, life~ (1.0-2.5) s and z~(0.5-1.2) m, respectively. the specific interfacial surface s is the interfacial area per unit volume [m2/m3]. it is one of the most important indices among others. with the assumptions of normal (gauss) size distribution and spherical shape of the drops, it can be approximated as s~3.103/r~(400-800) m2/m3 depending on gas speed u~(10-20) m/s and volumetric flux of water ~(0.02-0.10) m3/m2s. these estimates are in good agreement with the direct experimental data 17 (fig. 2). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 2. specific interfacial surface s versus volumetric flux of water . 1u= 10 m/s, 2u= 15 m/s, 3-u= 20 m/s. to generalise, it should be stated that in deciding on scrubbing speed, the dominance of gas momentum over liquid momentum ( u)g>( u)l ( 13 ) is the single crucial constraint of lsst applicability. experiment to suit the similarity theory, the experimental apparatus for lsst investigation was designed as a transparent 1:10 reduced scale model of a typical cylinder-shape full-scale scrubber of 50000 nm3/h gas load (fig. 1). values of the main criteria remodel= renature, ped, model=ped, nature, scmodel=scnature were satisfied. other criteria, including fr and thermal, were held constant whenever possible. measurements of the contacting and separation chambers were equal to d=0.4 m, l=1.1 m and d=1.0 m, l=0.7 m, respectively. total gas load, gas spead and volumetric flux of water varied within the limits vg~(1.0-3.0) m3/s, u~(8-25) m/s, and ~(0.02-0.10) m3/m2s, respectively. polluted primary gas contains various admixtures (e.g., phenol, ammonia, hydrochloric acid). below are given data regarding primary gas polluted with the mixture {(2-8)% so2+(1-4)%so3}. with the control system, highspeed (up to 5000 shots/s) photography and on-line measurement of the main process characteristics were possible. other details can be found elsewhere 10,17, 18. the prime object lies in the direct experimental determination of the main technological (residence time, fall time and distance, interfacial area, size distribution and zoning of the dispersed phase) and sorption indices (heat/mass-exchange coefficients ), which are dependent on lsst operating parameters (gas load, scrubbing rate and volumetric flux of water) and lsa design features (geometric and aspect ratios, positional relationship of various units and hydraulic resistance). experimental data combined with the essentials of dimensional analysis provide adequate lsst description to yield simple analytical quantities for practical lsa design. relevant data17,18 are shown in figures 2-4 and table 1 and can be briefly summarized. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 1. the main lsst and lsa scrubbing variables indices wet-bed venturi tube one-stage lsa 1 gas load (max), vg nm3/h ~180 000 <100 000 300 000 2 number of stages in one set 1-2 1 any 3 operational regime co/counter only coflow compound 4 interfacial area, s m2/m3 max 250 max 400 400-800 5 gas speed, u m/s 20-40 50-120 10-20 6 contact time, s 0.05-0.30 0.02-0.10 0.20-2.50 7 volumetric flux of water m3/m2s 0.04-0.10 0.40-1.10 0.02-0.10 8 hydraulic resistance h, pa 2000-2500 3000-8000 <1400 9 coefficient of the gas mass exchange v,g m 3/m3s 5-8 7-12 20-30 (see text) 10 cleaning efficiency*(dust)% <85 <95 >98 11 cleaning efficiency (oxides) ~(5090)% ~(60-95)% ~(70-99)% 12 dimensions (averaged), m ~ 5.0 / 10.0 ~ 3.0 / 6.0 ~ 3.5/10.0 13 dry mass (averaged), kg ~ 10000 ~ 6000 ~ 9000 notes : * strongly depends on size distribution r=r(u). specific interfacial surface s was determined experimentally by a known chemical method19. s is almost independent of the gas speed, while it is strongly dependent on volumetric flux of water (fig. 2). this dependence can be approximated with an accuracy of 12% in the form s 1775 u0.2 0.63 ( 14 ) fig. 2 and eq. (14) conceptually confirm the validity of the above presented theoretical approximation. at the same time, the weakened s-u correlation seems to be the result of some liquid loss from the contacting chamber as the gas speed increases. both mass holdup of liquid gl kg gl = gl/v =0.209 u 0.79 0.92 ( 15 ) and its residence time life in the contacting chamber mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset life = lcont/ ( 16 ) are strongly dependent on volumetric flux of water . the volumetric holdup of gas in the contacting chamber vg is defined as the difference between the volume of contacting chamber v and volumetric holdup of liquid vl=gl/ l vg = v vl ( 17 ) usually, volumetric fraction of gas g= vg/vl falls in the range (0.90-0.98). the main interest was focused on the direct experimental determination of mass exchange efficiency and search for opportunity of its intensification in the context of the unsteady phase interaction. some of the generalised results are briefly summarized as follows. mass-exchange efficiency of lsst was estimated with the help of the following transfer coefficients. the coefficient of the liquid mass exchange v,l represents volumetric gas flux from the gas phase to the liquid phase with respect to the whole gas-liquid volume. it was determined experimentally by the example of carbon dioxide co2 desorption from its aqueous solution. v,l-values are dependent on the gas speed and volumetric flux of water (fig. 3); the semi-empirical average approximation is in the form v,l = 0.457 u0.25 0.86 ( 18 ) with an accuracy of 10%. a comparison of eq. (14) and (18) shows that the gas speed affects both v,l and s equally. as a result, the coefficient of the surface mass exchange v,s , i.e., volumetric gas flux from the gas phase to the liquid phase with reference to the specific interfacial surface s, seems to be practically independent of the gas speed. both the direct experimental plot of v,s vs u (fig. 3) and semi-empirical analytic approximation v,s = v,l/s =0.0003 u0.05 0.23 ( 19 ) prove this feature of mass exchange in lsa. fig. 3. coefficient of the liquid mass exchange v,l versus volumetric flux of water , 1u= 10 m/s, 2-u= 20 m/s. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the coefficient of the gas mass exchange v,g, i.e., volumetric gas flux from the gas phase to the liquid phase with reference to the gas volume, was determined experimentally through the rate of adiabatic evaporation of water. the weaker the solution, the more valid the method 20. therefore its use is justified considering that the solution strength does not exceed ~ 20%. the correlation of v,g with the length of the conacting chamber for a different gas speed u and volumetric flux of water is displayed in fig. 4. the coefficient of the gas mass exchange v,g represents (by definition) the average product of some local index ( v,g)loc and local interfacial surface sloc. therefore, its decrease along the contacting chamber length is attributed to the decrease of either ( v,g)loc or sloc. the former could occur if the diffusion on the gas side through the boundary layer quickly decays for any reason (e.g., fast equalisation of phase potentials). otherwise, the governing factor is the duration of boundary layer formation. as to the possible decrease of sloc, it may occur due to either coagulation (see above) or the effect of initial and boundary conditions. any other admissible reason for v,g variation is dismissed because of the high values of re and pe-criteria (re~ 105, i.e., it is turbulent regime, while pe~ 103 , i.e., convection is the dominant process). the elbow (saturation) of the curve in fig. 4 marks the termination of the transitional unsteady period of two-phase flow formation and transition to the steady flow regime. fig. 4. coefficient of the gas mass exchange v,g versus height of the contacting chamber lcont. a specific feature of the transfer coefficient lies in the fact that it is the most generalised index of scrubbing efficiency and hence it is a function of both the operating conditions = (p, t, u, ) and design features = (l, d, , s). however, the former is more or less restricted and cannot be widely varied, while the latter is completely dependent on hydro/gas-dynamics. this means that the mass exchange can be restrictively varied only by optimisation of the lsa design. thus, from the specific point of view of the lsa designer, data in fig. 4 should be read as a practical recommendation for initial approximation of the contacting chamber dimensions. depending on the given flow sheet and customer’s demands, this quantity will be specified later in the project development. the achieved values of index can be found in figures 3 and 4 and table 1. the simplified entry of the overall purification efficiency can be presented in the form5: g ~ . s ( 20 ) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset here g is total amount of captured and fixed impurity (whether it be gas, liquid or solid), is volumetric flux of liquid, is residence time, s is specific interfacial surface, while represents mass exchange coefficient. the average values of these quantities for lsst typical regimes fall within the following ranges. volumetric flux of water is predetermined by gas momentum ( u)g and lies in the range ~(0.02-0.10) m3/m2s. the residence time is the sum of the fall time and one of the ascending co-flow along the contacting chamber 1=l/u, being equal to life= f+ 1~(0.2-2.5) s. it should be stressed that increase of the gas speed from u1 to u2=nu1, n>1 implies not only the growth of the interfacial area, but also quadratic increase in the hydraulic resistance h=h2/h1~ (u2) 2/ (u1) 2~ (nu1) 2/ (u1) 2 n2, enforced carrying away of the dispersed phase from the contacting chamber and non-linear decrease of contact time ~( u)-1. in doing so, the product (s ) is correlated in such a way that it is a non-monotonous extremal function. location of its extremum is dependent on the sorption efficiency and cannot be estimated a priori. design and engineering features lsa units must provide both the main and some subsidiary technological operations. the inlet section is the domain of the incoming gas flux reorganization (fig. 1). it is designed for gas input and (should the need arise) the cooling of the gas by water injection. these operations can be separated; however, the combined design offers definite advantages. a contacting chamber of typical length/diameter ratio (l/d) cont~(1.0-1.5) serves for mixing and sorption, as well as regime stabilisation in cases of wide gas load variation or frequent (spontaneous) input/output operations. for this purpose, it can be arranged with a stabilising circular collar. the latter is installed so as to divide the inlet and contact zones. usually, this collar is the split ring, the details (shape, number of segments and coefficient of wetted passage =sfree/scont) being completely determined by the flow sheet. the height of the liquid bulk in the separation chamber hlevel is usually chosen in such a way as to provide a hydrostatic head on the recycling back-pipes h=hlevel-hpipes~(0.1-0.3) m. in turn, both the overall cross-section of back-pipes spipes~0.785d2( h)1/2/ (2g)1/2 (here = 1.8.( h)0.92 -0.61 is the coefficient of liquid discharge) and their total number m~ spipes/0.785d2 are dictated by volumetric flux of water and gas speed u. the fixed centrifugal separator also has some special features, particularly the efficiency of phase separation, which is very sensitive with respect to the separator geometry, including number, height, and curvature of curvilinear blades. the dimensions of the separation chamber are dictated primarily by the demands of the total precipitable water (including water vapors and droplets) in the final exhaust, being dependent as well as on the dryness factor of the primary polluted air. for this demand to be fulfilled, the gas speed along the separation chamber usep=f(u, r)air should be smaller than the deposition rate uair(rair) of airborne water droplets of some definite rair-drop. usually, the ratio (l/d)sep~(0.60.8) provides a reasonable solution to this problem. in this case, the ratio between the diameters of the contacting and separation chambers falls in the region dsep/dcont~(ucont/usep) 1/2~(2-2.5). in its turn, any lsa can be arranged as a multi-stage unit enclosed in a common shell, any stage in a series being independently optimised along any parameter 9,10. as this occurs, the next stage is either an identical copy of the preceding stage (so-called cascade lsa) or distinctive in any respect (combined lsa). mailto:topacademicjournals@gmail.com vasili i. dimitrov 24 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a cascade lsa is applied for fine cleaning, since the output of the previous stage is simultaneously the input reative to the following one. a combined lsa is used when each taken separately stage is optimized along another parameter. one remark of material significance in current engineering practice, the customer’s demands are a point in any real design. these demands are usually well known. they include efficiency of purification, minimisation of budget investment and/or operational cost, minimal water consumption, dryness of the exhaust, optimal dimensions, fool-proof design (i.e., safe maintenance achievable with low-skilled operator) and sometimes unforeseen demands. the order of preference (priority) of these demands, together with the given flow sheet, could result not only in simple changes of some details (e.g., dimensions) or even radical ones in design (one, two or three-stage lsa), but often predetermine the possibility of using wet scrubbing technology. generally, this priority sequence is unpredictable, hence it should be posed and approved a priori. unpredictable priority sequence of customer’s demands, specificity of lsst hydro/gas-dynamics, variable combination of physico-chemical parameters, character of the particular industrial site, as well as the very essence of scrubbing, lead to the point that lsa manufacturing is not repetitious work. there are sometimes apparent similarities (e.g., the same scale, impurities, physical conditions and degree of purification), which, in fact, are embodied into drastically different real plants. as is evident, to implement particular lsa, both standard design and intuitive engineering solutions (know-how) need to be used. in other words, each real case is unique and requires its own engineering design 8,10-12. discussion and conclusions comparison of relevant sorption and technology lsst ability factors with those of some conventional technologies, such as wet-bed3,5 and venturi tube techniques21,22 can be found in table 1. they show that lsst combines the main merits of conventional co/counter-flow technologies, while being free of their defects. two key points that provide the main lsst advantages (primarily high mass-exchange efficiency) are the low absolute gas speed and spontaneous change of the counter-current regime to the co-current one. the decrease of typical gas speeds of conventional co/counter-flow technologies u~(20-40) m/s down to the typical lsst-speeds u~(10-20) m/s does not cause deterioration of the process on the whole; on the contrary, it enhances scrubbing efficiency while reduces control requirements. the main lsst merits and demerits can be generalized as follows. as indicated, both the process as a whole and some of its stages in particular (e.g., mixing, selffragmentation and phase separation) are very sensitive to the lsa geometric proportions. hence, more sophisticated and careful study of the engineering design (at the stage of the project development) and manufacturing (at the stage of lsa implementation) are necessary. design errors or inaccurate manufacturing results in dramatic deterioration of scrubbing efficiency. it may be concluded that lsst as a whole presents a successful and effective combination of well-known cocurrent and counter current technologies. it provides for a stable scrubbing operation and allows for reasonably simple control and monitoring of the latter. the process is conducted by using scrubbers of special design lsa. thus, the most specific features of lsa can be summarized as follows: 1. lsa is free of any (e.g., mechanical and/or pressure) load; hence it is safe in operation. 2. lsa has no unreliable structural units (e.g., injectors and/or any moving elements) that need careful maintenance; hence a highly skilled operator is not needed. it is a foolproof and serviceable structure. vasili i. dimitrov 25 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. lsa does not need any auxiliary facilities (e.g., re-circulation pumps). 4. lsa has low hydraulic resistance. nomenclature design indices l[m], d [m] and v [m3] length, diameter and volume, respectively, physico-chemical indices [kg/m3] density, [kg/s2] surface tension, [kg/m.s] dynamic viscosity. hydro/gas-dynamic indices d [m2/s] diffusion constant (eq. 1, 2), h [pa] hydraulic resistance, u [m/s] speed, vg [m 3/s] total gas load, gl [kg/m3] liquid-water content, gl [kg], vl[m 3] mass and volumetric holdup of liquid, respectively, gg [kg], vg[m 3] mass and volumetric holdup of gas, respectively, [m3/m2.s] volumetric flux of liquid (current water content) heat/mass exchange indices v,g [m 3/m3.s] coefficient of the gas mass exchange (volumetric flux from the gas phase to the liquid phase in relation to the gas volume), v,l [m 3/m3.s] coefficient of the liquid mass exchange (volumetric flux from the gas phase to the liquid phase in relation to the whole gas-liquid volume), v,s [m 3/m2.s] coefficient of the surface mass exchange (volumetric flux from the gas phase to the liquid phase in relation to the specific interfacial surface), s [m2/m3] specific interfacial surface (interfacial area per unit volume), subscripts and abridgements cont contact, f fall, g gas, ini initial, l liquid, loc local, s surface, sep separation, sf self-fragmentation. references list and codes of air pollutants, 1991, ussr state department on environment protection, moscow. technische anleitung zur reinhalyung der luft (ta luft), general administrative regulation pertaining the federal emission control law (technical instruction on air quality control), 1986, germany. chao, b. t., 1969, transient heat and mass transfer to a translating droplet, trans. asme, ser. g, j. heat. transfer, 91 (2), 273-281. levenspiel, o., 1972, chemical reaction engineering, john willey and sons, inc., new york-london-sydney. todes, o. m., 1983, wet-bed absorbers (rus), nauka, leningrad. gupalo, y. p., polianin, a. d., and riazantzev y. s., 1985, heat/mass-exchange between the flow and reacting particles (rus), nauka, moscow. hesketh, k. c., and howard, e., 1996, wet scrubbers, willey, n-y. evgrashenko, v. v., et al., 5. 03. 1982, low-speed foam absorber, ussr a.c. 748940, ibid. 12.11.1982, ussr a.c. 839094. vasili i. dimitrov 26 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset evgrashenko, v. v., 1983, design and industrial installation of co-flow scrubber, ph. d. thesis, institute of chemical fertilizers and poisons, moscow. ivanov, v. v., 1988, fast heat/mass-exchange in lsa, ph. d. thesis, institute of chemical fertilizers and poisons, moscow. dimitrov, v. i., krainev, g., evgrashenko, v. v., slinko, m., and ivanov, v.v., 8.01.1990, device for the intensive mass-change, ussr a.c. 1562015. dimitrov, v. i., ivanov, v. v., krainev, g., and evgrashenko, v. v., 1992, lowspeed foam absorber, israel license 102192. ruckenstein, e., 1970, unsteady mass transfer near fluid-liquid interfaces, chem. eng. sci., 25 (11), 1699-1708. ruckenstein, e., and muntean, o., 1970, mass transfer between a bubble and an oscillating liquid, chem. eng. sci., 25 (7), 1159-1166. dimitrov, v. i., and bar-nun, a., 1999, a model of energy dependent agglomeration of hydrocarbon aerosol particles, j. of aer. sci., 30 (1), 35-49. johnson, a. i. hamielec, a. e., and haighton, w. t., 1967, mass transfer with chemical reaction from single gas bubbles, aiche j., 13 (2), 379-383. evgrashenko, v. v., kernerman, v. a., ivanov, v. v., krainev, g., slinko, m., holpanov, l. p., and dimitrov, v. i., 1987, phase contact in a foam scrubber with the ascending single-pass flow, chemical industry, 4, 4347. krainev, g., evgrashenko, v. v., slinko, m., dimitrov, v. i., and ivanov, v. v., 1987, estimation of mass-change in two-phase flow, chemical industry, 1, 36-38. linek, v., and mayrhoferova, j., 1969, the chemical method for the determination of the interfacial area, chem. eng. sci., 24 (3), 481-496. calderbank, p. h. 1959, mass-exchange in water and aqueous solution of two-phase systems, trans. inst. chem. eng., v37, n3, 173-184. vatanuk, w., 1981, estimating size and cost of venture scrubbers, chemical engineering, november 30, 93-96. ollero, p., 1984, program calculates venture-scrubber efficiency, chemical engineering, may 28, 103105. academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset dark matter and dark energy can be held in the 3-cosmic framework through original string theory hsien-jung ho new idea research center email: newidea.ho@gmail.com doi: https://doi.org/10.5281/zenodo.13982179 abstract: scientific development has reached a very high level today, but in the natural sciences, research still encounter bottlenecks. the problems posing the greatest headache for scientists lay with dark matter and dark energy. dark matter of the universe is a hypothetical form of matter, which puzzles scientists more than 80 years and no solution yet. most experts think dark matter is abundant in the universe and has had a strong influence on its structure and evolution. in the observable universe, there is no indication that the universe is expanding at an accelerating rate, and cosmologists have hypothesized the existence of some unknown "dark energy" to explain this phenomenon. in 2018, plank satellite detects tiny temperature fluctuations in the radiation of the universe. these distributions of fluctuation reflect the baryon density of the universe before galaxies have yet to form. normal matter from galaxies and stars accounts for only 4.94 % of the universe's composition, with the rest missing substance, including dark matter, which accounts for 26.64 %, and mysterious dark energy, which accounts for 68.42%, so, the invisible composition of universe is 95.06 %. scientists believe that dark energy is the force that tears the universe apart, but dark matter condenses all things, and that the interaction of these two forces forms the structure of the universe, as we know it today. as long as we can understand the assembling speed of the galaxy, we can understand dark matter, also understand the power of dark energy tearing the universe at the same time. therefore, dark matter may be the best tool to study dark energy in the end. to understand dark matter now, we will probably get an answer from the most famous “string theory”. keywords: dark matter, dark energy, density, universe introduction: the original string theory is based on nine-dimensional space and one-dimensional time, i.e., a ten-dimensional space-time, which is considered to universally exist. according to “causality”, an effect cannot occur before its cause, which means time has one direction and cannot be divided into some different parts. so one-dimensional time is taken as a common standard in order of events in the universe. following the “anthropic mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset principle”, which is the simple fact that we live in a universe set up to allow our existence, three-dimensional space and one-dimensional time are taken as one cosmos as our living world. therefore, the nine-dimensional space can be divided into three portions, and each portion has a common time standard, which means that there is a 3-cosmic framework in the universe, called the triple cosmoses, i.e., multiverse. in the triple cosmoses, according to string theory among any cosmoses, there are no basic interactive forces of nature except gravity, i.e., the graviton in the field of gravity can penetrate all the cosmoses; however, the electromagnetic wave (light) cannot. so dark matter may be situated in the cosmoses other than ours; in other words, the triple cosmoses can contain dark matter. the best method of exploring dark matter is to start from the earth where we live. in the current earth model utilized in seismological investigations, such as body-wave travel times, surface-wave dispersion, and free oscillation periods for researching the chemical composition and the density distribution of the earth, one can analyze some data of the earth. we use the preliminary reference earth model (prem) as the standard earth model. according to the characteristics of earth's interior, equitably examining its constitution, composition, density, and pressure from a different view of the core, the special arguments are put forward. there are some arguments in the topic of the cmb as in the following: 1. in 1948, ramsey and in 1973, lyttleton have challenged the concept of an iron core that the cmb is the boundary of ramsey's phase-change not silicates and iron core interface. 2. in 1965, knopoff showed that bulk modulus keeps constant that density distribution should be continuous at the cmb. 3. in 1968, buchbinder studied the variation in reflection amplitudes of seismic wave and found that show a phase-change at the cmb. 4. in 1987, morelli and dziewonski found the topography of cmb more than 10 km that shows the relief is dynamically supported and provides coupling between the solid mantle and the fluid core. it is inferred that solid rock and molten rock, or the magma change states interactively and the density distribution is continuous at the cmb, therefore, we figure out a new earth model as figure 1. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1. seismic velocity and density in the earth’s interior of prem and the new earth model. 1. in 1995, hecht discovered under the frozen wastes of siberia that platinum has come all the way from the core to ground shows a single convection cell. 2. in 2018, perrin discovered the intact remains of a natural nuclear fission reactor in a uranium mine at oklo of gabon and demonstrated from the radioactive elements can generate nuclear energy in the core. 3. in 2023, horton et al. argue that the extremely high-3he/4he helium measured in terrestrial igneous rocks, in olivine’s from baffin island lavas, whose primordial helium may be leaking from earth's core. 4. in august 2002, oak ridge lab of united states report a new achievement in scientific research that 6371 km below the surface of the earth's center has a diameter of 8 km, consisting of uranium and plutonium fast breed natural fission reactors, which can generate the fission heat. from above statements we can figure out in the interior of earth a great convection cell that the flow of the magma and the solid or molten rock migrating up to the crust and down across the cmb to the lowermost f-layer of the outer core as figure 2. in the low viscosity f-layer of the outer core, the high temperature causes some elements and oxides of magma to undergo oxidation-reduction reactions and separate due to its gravity. the great amount of heat is produced from chemical reactions in the f-layer and radioactive element generated nuclear energy in the earth’s interior which serves as the main power source for the geo-dynamo of the great convection cell [1]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2. a schematic diagram of a great convection cell and heat flow, and the composition of earth’s interior. based on the new conception and applying a simplified method calculates the data of the earth that the density distribution follows the divisions of prem divided into 94 levels, including 82 thin shells. the thickness of each shell is not greater than 100 km and so small compared with the earth's radius of 6371 km that the density is regarded as linear variation within it. then, a simplified method is applied to calculate the information of the earth in order to simplify the calculating work. the formula for the mass m of a uniform sphere can be derived through m = (4/3) πρr3. the mass ∆m of each shell in the earth's interior can be calculated through ∆m＝ (4/3)πρtrt 3－(4/3)πρbrb 3 (1) where: ρt, ρb are the densities at the top and the bottom, respectively, of one shell, and rt, rb are the radii of the top and the bottom in a shell. because the difference between rt and rb is so small and the density is regarded as linear variation in the shell, the mean value of both ρt and ρb is substituted for ρt and ρb in order to simplify the calculation. then equation (1) becomes ∆m＝ (4/3)π (r t 3－r b 3) (2) the moment of inertia ∆ｉ of each shell in the earth's interior can be calculated through mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ∆ｉ＝ (8/15)π (rt ５－rb 5) (3) from fluid mechanics, in a region of uniform composition, which is in a state of hydrostatic stress, the gradient of hydrostatic pressure is expressed by dp/dr＝－ ɡρ (4) where: p, r are the pressure and the radius, respectively, at the region; ρ is the density at that depth; ɡ is the acceleration due to gravity at the same depth. if the effect of the earth's rotation is negligible, the potential theory shows that ɡ is resulted only from the attraction of the mass m within the sphere of radius r through ɡ＝gm／r2 (5) where: g is the gravitational constant (6.6726×10-11m3/kg.s2). equation (5) substitutes into equation (4) and integrate it. in order to simplify the calculation, ρ and m are substituted by and , which are considered the constants in the thin shell and irrelative to the p and r. the result becomes ∆p＝(1/rb－1/rt)g (6) where: ∆p is the difference in pressure between the top and the bottom in a layer of the earth, and is the mass of a sphere as the mean value of the masses of the sphere within the top radius rt and the bottom radius rb, respectively, of a shell. equation (6) cannot be applied to the center of the earth where is a discontinuous point. to integrate the portion of the center, the other form is applied as ∆pc＝(2/3)πg 2rc2 (7) where: ∆ pc is the difference in pressure between the radius rc and the center of the earth at the center portion. the acceleration due to gravity ɡ of each layer can be derived from equation (5). according to the observation data, the moment of inertia about the polar axis of the earth is 0.3309mere2 and about an equatorial axis is 0.3298mere2. the earth is regarded as a sphere, of which the moment of inertia is determined to be 80286.4×1040 g.cm2 by taking the mean value of both figures, where me is the earth's mass of 5974.2×1024 g and re is the equatorial radius of 6378.14 km. to examine the accuracy of applied equations, we apply the density distribution of the prem to calculate the earth's mass, moment of inertia, pressure and acceleration due to gravity. the calculated values of the earth's data using simplified method from the density distribution of the prem as compared with the values of the current data in table 1 (http://newidea.org.tw/pdf/s60.pdf). the calculated data of the prem are listed in compared with that of the current data and the prem are listed and table 2. table 2. the calculated values of simple method from the density distribution of the earth as compared with the data and the prem and the current earth. mailto:topacademicjournals@gmail.com http://newidea.org.tw/pdf/s60.pdf academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset data of the earth mass moment of inertia pressure at cmb pressure at earth center gravity at cmb gravity at earth surface unit 1024 g 1040g.cm2 k bar k bar cm/sec2 cm/sec2 prem & current 5974.200 80286.400 1357.509 3638.524 1068.230 981.560 calculated values 5973.289 80205.664 1358.335 3655.973 1068.680 981.959 difference % -0.0152 -0.1006 +0.0608 +0.4796 +0.0421 +0.0406 from table 2 the deviations of the calculated earth's values from the data of the prem and the current earth are nearly within 0.1％, except the pressure at the earth center. it indicates that the calculated values are very close to the current data and the simplified method is acceptable and useful; however, the calculated pressure of 3655.973 kbar at the earth's center is higher than the data of the prem of 3638.524 kbar by 0.4796 %, about 8 times of deviation at the cmb. we compare all the calculated pressures of the simplified method with that of the prem by the curve of deviation e in the pressure p of the prem in figure 3. figure 3: the pressure p of the prem and the deviation e of the calculated pressure of simplified method from the value of p. the deviations e of pressure curve from the crust to the cmb is showed nearly as a straight line, indicating that the calculated pressures have the systematic errors in view of the error theory. but from the cmb to the earth's center, the slope of curve e sharply increases above the dashed line, which is the straight line extended from the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cmb. it indicates that there is a considerable discrepancy within the core. we may suppose that the structure of the core in the prem, which greatly affects its core pressure, is something wrong. the insufficiencies of the earth's mass and moment of inertia, called the missing mass and moment of inertia, both are relative to the gravity that belong to the dark matter in astrophysics. it can only be obtained by comparing the observed data of the earth but cannot be detected directly and answered clearly through the ordinary earth sciences. in order to solve the problems of the insufficiencies, a new study of the earth is attempted by utilizing the contemporary physics. if we can successfully explain that the insufficiencies exist in a suitable condition, a new earth model will be established. proceeding with the assumption, the missing mass and moment of inertia of the earth are taken as the cold dark matter, which may constitute a normal planet. in order to find some solution in this article, the dark matter is compared to mars. the average radius of mars is 3397 km, and the mass 642.40×1024 g. in 1989, kaula et al studied the moment of inertia of mars and got the maximum allowable mean value is 0.3650 mr², i.e., 2689.8×1040 g.cm2. the insufficient data of new earth models roughly approach to the mars’, so the dark matter is considered as a planet, called a dark planet, of which the form is similar to mars and its characteristics are based on the inner planets of the solar system. in order to cut a figure of the dark planet, it is considered as a sphere, whose radius and density can be calculated from the insufficiencies of the earth’s mass and moment of inertia through the simplified method. the data of the dark planet can be calculated as following. considering the density of rock on the surface of the earth and the moon, the surface density 2.70 g/cm3of the dark planet is proposed. under the condition that the density of a layer is proportional to its depth, a trial value of density at the center of the dark planet is selected and applying the equations (2) and (3) to calculate the mass and the moment of inertia of each shell, the total mass and moment of inertia of it should be gotten. because the radius and the center density of the dark planet are the hypothetical values, but the total mass and moment of inertia are necessary to correspond to the insufficiencies of the earth's; therefore, it is necessary to use a trial and-error approach to determine the proper radius and the center density. since the earth's orbit around the sun may be affected by the gravity of the dark planet, but no abnormal effect on the earth has been observed. an assumption is suggested that the gravity centers of the earth and the dark planet coincide with each other at the same point. it is inferred from the phenomenon in which the same side of the moon always faces the earth that means the earth and the dark planet may rotate synchronously. assuming that the gravity centers of the earth and the dark planet coincide at a single point, and both rotate synchronously, the total values of mass and moment of inertia may be obtained from the sum of them. based on mechanics, the gravity at each shell inside the earth is affected by the mass of the earth and the dark planet within its radius. the pressure difference ∆ between the top and the bottom of a shell within the earth is calculated through: ∆ ＝ ( 1/rb－ 1/rt )g (8) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset where: is the mean value of the total mass of the earth and the dark planet within the radius rt and rb. equation (8) cannot be applied to the earth's center. the average density of the central portion combined with the earth and the dark planet within the radius rc can be calculated through ＝ ( mc＋md )／[(4/3)πrc3] (9) where: mc and md are the masses of central portion in the earth and in the dark planet, respectively. the difference of pressure ∆ between the top and the center of the central portion in the earth can be obtained through ∆ ＝(2/3)πg rc2 (10) based on the characteristics of the inner planets of the solar system except mercury, the bigger the radius of a planet, the higher the average density is, so the radius and the average density of a suitable dark planet must be compatible with the characteristics of inner planet in solar system. the data of the new earth models and dark planet are compared with the data of the current earth and the prem in the table 3. table 3. the calculated data of the new earth models compared with the data of the current earth and the prem k in d o f e arth 's m o d el the earth planet the dark planet s u itab ility r ad iu s a v er ag e d en si ty m as s m o m en t o f in er ti a c en te r d en si ty c en te r p re ss u re m o m en t o f in er ti a r ad iu s a v er ag e d en si ty m as s m o m en t o f in er ti a m o m en t o f in er ti a unit km g/cm3 1024g 1040 g.cm2 g/cm3 kbar c km g/cm3 1024g 1040 g.cm2 c prem 637 1 5.5150 5974.2 00 80286.40 0 13.088 48 3638.524 0.330 9 new model 637 1 4.7284 5121.8 20 76126.84 1 9.4982 1 2805.297 0.366 2 3700.3 75 4.0161 852.38 0 4159.559 0.3564 goo d the precise data of the earth and the dark planet are calculated from the density distribution of the new earth model, the data of the earth planet is listed in tables 4 (http://newidea.org.tw/pdf/s91.pdf), the dark planet is listed in table 5 (http://newidea.org.tw/pdf/s92.pdf) and the global data of the new earth model in table 6 (http://newidea.org.tw/pdf/s93.pdf). the pressure p and the acceleration due to gravity ɡ of the new earth model compared with the prem are shown in figure 4. in this suitable model the slope of density curve from a depth of about 400 km of the upper mantle through zones c, d and e to the upper boundary of f-layer is nearly a straight line, which means the density increase in proportion to its depth in accord with general physical phenomenon, so mailto:topacademicjournals@gmail.com http://newidea.org.tw/pdf/s64.pdf http://newidea.org.tw/pdf/s91.pdf http://newidea.org.tw/pdf/s92.pdf http://newidea.org.tw/pdf/s93.pdf academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the new earth model is acceptable as the proper new one. figure 4. the diagram of the gravity ɡ and the pressure p compares between the new earth model and the prem. the average radius of mars is 3397 km, the mass 642.40×1024 g, and the average density 3.912 g/cm3. both values of the radius and the average density of the dark planet in the new earth model are bigger than those of mars, therefore, this model is found to be the more suitable one. we can find the pressure curve of the new earth model is smoother than that of the prem below the cmb. in the gravity curve of the new earth model, there are two deflection points in the curve that the one is at 2670.625 km in depth at the radius of the dark planet, and the other is at the inner core boundary (icb). the earth has a mass of 5121.820×1024g, a moment of inertia of 76126.841×1040 g.cm2, an average density of 4.7284 g/cm3. the earth's center has a density of 9.49821 g/cm3and the pressure of 2805.297 kbar. the reduced values of the earth's data from those of the current earth are due to the existence of the dark planet. the dark planet has a radius of 3700.375 km, a moment of inertia of 4159.559×1040g.cm2, an average density of 4.0161 g/cm3and a mass of 852.380×1024g about 1.33 times of mars. the data of the new earth model compared with those of the current earth and the prem are listed in table 7. table 7. the data of the new earth model compared with the data of the current earth and the prem. data of planet radius mass inertia of moment average density center density center pressure coef ficient unit km 1024g 1040 g.cm2 g/cm3 g/cm3 kbar c prem & current earth 6371.000 5974.200 80286.400 5.515 13.08848 3638.524 0.3309 earth planet 6371.000 5121.820 76126.841 4.7284 9.49821 2805.297 0.3662 dark planet 3700.375 852.380 4159.559 4.0161 7.96097 1115.272 0.3564 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset we apply the different density distribution curves of the model in the core to calculate the data of earth and then compare it with the existing current data of earth. the insufficient mass and moment of inertia are the missing matter which are taken as the parts of dark matter, and then a suitable new earth model is developed. apply the simplified method to evaluate the earth's mass and moment of inertia, which are found to be only 85.73％ and 94.82％ respectively of the current data. by the two insufficiencies of earth's mass and moment of inertia, formulating the reasonable assumptions, a dark planet inside the earth has been figured out, then calculate gravity and pressure in every depth within the earth to check suitability or not. finally, a planet of dark matter, called dark planet, with a radius of 3700.375 km, about 1.33 times of mars, is reasonably inside the earth in the extra dimensions of space other than ours. it is hard to examine the existence of the dark matter directly; however, that can be recognized from chandler wobble. referring to the orientation of the rotation axis of the earth in space in addition to both precession and nutation, there is a wobble on the instantaneous axis of rotation of the earth itself. the wobble alters the position of a point on the earth relative to the pole of rotation. in 1891, chandler pointed out that there are two distinct kinds of the wobble periods. one is a period of 12 months, and the other is a period of 433 days, about 14 months. the former, called annual wobble, is obviously affected by the seasonal climate. the latter, called chandler wobble, has not been solved the problem for more than one hundred years. the chandler wobble is a small deviation that amounts to change of about nine meters at the point in the surface of the rotation axis of the earth. it is inferred from the phenomenon in which the same side of the moon always faces the earth that means the moon and the earth rotate synchronously. the same phenomenon will happen to the earth and the dark planet that both rotate synchronously, but the rotation axes of both are impossible coinciding with each other; i.e., an angle between the two rotation axes produces the chandler wobble as the precession and nutation because of the sun and the moon on non-parallel rotation axes with the earth’s. therefore, the effect of chandler wobble may confirm the existence of a dark planet inside the earth but in the other cosmos than ours[2]. to research dark energy, we apply the eight data of cosmological parameters of wilkinson microwave anisotropy mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset probe (wmap) results and planck satellite results from 2003 to 2018 for 15 years, to form the table 8 of cosmological parameters from them. table 8. the cosmological parameters from wmap and planck satellite source symbol wmap 1st year. wmap 3rd year wmap 5th year wmap 7th year wmap 9th year planck satellite 2013 planck satellite 2015 planck satellite 2018 ho 71.0 70.4 70.5 70.2 70.0 68.14 67.31 67.32 ωʌ 73.0% 73.2% 72.6% 72.5% 72.1% 69.64% 68.5% 68.42% ωm 27.0% 26.8% 27.3% 27.44% 27.9% 30.36% 31.5% 31.58 ωb 4.4 % 4.41% 4.56% 4.58% 4.63% 4.79% 4.9% 4.94% ωc 22.34% 22.39% 22.8% 22.9% 23.3% 25.43% 26.42% 26.64% t0 13.7gyr 13.73 gyr 13.72 gyr 13.76 gyr 13.74 gyr 13.784 gyr 13.80 gyr 13.80 gyr from the table, the dark energy density ωʌ from 1-year wmap results to planck 2018 results vi for 15 years, the value from 73.22% decreases gradually down to 68.42%, decreasing 4.8%, but the total matter density ωm from 1-year wmap results to planck 2018 results vi, the value from 26.78% increases gradually up to 31.58%, increasing 4.8%. the dark energy loss is equal to the increase of total matter that is consistent with “the big bang theory”. the cosmological parameters of planck 2018 results vi are taken as the current situation of the universe, we may imagine that at the firstly time of the big bang, the full energy (100% energy density) of the universe gradually loses, after 13.8 billion years later, remains 68.42% energy density, which is called dark energy density ωʌ, and creates 31.58% total matter density ωm, so, we should take the current dark energy as the residual energy of the universe after the big bang. due to the current composition of the universe, dark energy accounts for 68.42%, which is much larger than the 31.58% of matter. it can be seen that the universe is still expanding rapidly. after the big bang, 68.42% dark energy density ωʌ is remainder today, but the lost 31.58% dark energy density transforms into total matter density ωm, which contains 4.94 % baryon density ωb (normal matter) in our cosmos and 26.64 % cold dark matter density ωc in other cosmoses than ours. according to the table 8, ωc from the value mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 22.34% increases gradually up to 26.64%, increasing 4.3%, and ωb in our cosmos from the value 4.44% increases gradually up to 4.94%, only increasing 0.54%, and the ratio of both is 8:1. because matter transforms from energy after big bang, the baryon densityωb increasing value is very small, which indicates energy in our cosmos is so poor that we can label our cosmos as the low-energy-density. on the contrary, the matter in other cosmoses, i.e., the dark matter for our world, has an increase value of 8 times, indicating that dark matter density ωc in the other cosmoses has increased greatly, so we can label the other cosmoses as the high-energy-density cosmoses. after wmap and planck satellite detected, the current actual temperature of cosmic microwave background radiation (cmbr) is only 2.725 °k, which is awfully close to the absolute zero (0°k = −273.15℃), therefore, our cosmos of low-energy-density cannot contribute to expand at an accelerating expansion. under the 3-cosmic framework of the universe, the rate of expansion in the high-energy-density cosmoses will be much higher than that of a low-energy-density cosmos as ours. the cosmoses of highenergy-density cannot directly contribute to the expansion of our low-energy-density cosmos, but when the high-energy-density cosmoses rapidly expand, their matter (i.e., dark matter) will expand at high pace that will use gravitational force to drag on the stars of our cosmos away at the same pace. due to gravity, the dragging effect causes the effect of pulling the stars of our cosmos accelerating expansion [3]. based on the applications of ten-dimensional space-time of string theory, a 3-cosmic framework of the universe is developed that the problems of dark matter and dark energy in astrophysics may be solved as above [4], but still needs to be proved by the fine outcomes of physicists' new research. references ho, hsien-jung, 1993. reconstruction of the earth model and discovery of the interior dark matter, first symposium on ufo cross strait. china ufology institute, doi: https://doi.org/10.29924/remdm.db/collection0001. ho, hsien-jung, 2019. based on the space-time of string theory exploring dark matter inside the earth, journal of scientific and engineering research, 2019, 6(8):166-191. http://newidea.org.tw/pdf/s71.pdf. ho, hsien-jung, 2022. the 3-cosmic framework of the universe can hold dark matter and dark energy, journal of scientific and engineering research, 2022, 9(4): 67-77. doi: mailto:topacademicjournals@gmail.com https://doi.org/10.29924/remdm.db/collection0001 http://newidea.org.tw/pdf/s71.pdf academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset https://doi.org/10.5281/zenodo.10518988. ho, hsien-jung, 2023. there is 3-cosmic framework in the universe ─ including dark matter and dark energy, newidea research center, isbn 978-986-86319-3-9. http://newidea.org.tw/pdf/s90.pdf. mailto:topacademicjournals@gmail.com https://doi.org/10.5281/zenodo.10518988 http://newidea.org.tw/pdf/s90.pdf 060908-zpk230018 academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset next-gen maintenance for urban rail transit: an iot-5g system design 1xu, zhi-qiang and 2gao, yuan-yuan 1shool of automation and electrical engineering, dalian jiaotong university, dalian, 116028, liaoning, china 2shool of electronic engineering, changchun college of electronic technology, changchun, 130114, jilin, china abstract: vehicle operation and maintenance in the context of urban rail transit is of paramount importance in today's society, where vehicles serve as the primary mode of transportation. this article explores the establishment of an intelligent operation and maintenance system for urban rail transit vehicles, leveraging the internet of things (iot) with the support of 5g technology. the advent of fifth-generation (5g) network technology has garnered significant attention in the era of the internet due to its transformative capabilities. research by chettri lalit has highlighted the pivotal role that 5g can play in enabling the internet of things [1]. indeed, the robust functionalities of 5g are widely acknowledged. dolgui alexandre emphasized that 5g can facilitate end-to-end real-time connectivity at an unprecedented level, enabling comprehensive visibility through the internet of things [2]. notably, 5g has found diverse applications, as evidenced by xiao m l's research, which sought to enhance the video capabilities of 5g base stations [3]. siriwardhana yushan has also explored the potential of 5g in mobile augmented reality applications [4]. furthermore, the power internet of things stands as a domain that heavily relies on 5g technology. tao j s asserted that the fusion of 5g with the power internet of things brings substantial advantages [5]. mao s q, in his research, incorporated 5g to meet the escalating computing demands of the power internet of things [6]. collectively, these studies underscore the multifaceted utility of 5g. this article aims to harness the transformative power of 5g within the context of urban rail transit vehicle operation and maintenance. by integrating 5g with the internet of things, we propose an intelligent system that will revolutionize how urban rail transit vehicles are managed. this system is envisioned to provide real-time connectivity and visibility, enhancing operational efficiency, maintenance accuracy, and passenger safety. the proposed intelligent operation and maintenance system will leverage 5g's ultra-fast, low-latency communication capabilities to establish seamless connectivity among various components of urban rail transit vehicles. it will enable instant data exchange between the vehicles and central control stations, ensuring rapid response to emerging issues and proactive maintenance scheduling. real-time monitoring and data analytics will be at the core of this system, allowing for predictive maintenance based on actual usage patterns and wear and tear. keywords: urban rail transit, intelligent operation and maintenance, internet of things (iot), 5g technology, predictive maintenance mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1. introduction vehicle operation and maintenance refers to the operation, maintenance, and repair of vehicles. as the most important means of transportation in today’s society, vehicles are closely related to everyone’s lives. therefore, vehicle operation and maintenance in the context of urban rail transit are equally important. this article attempts to establish an intelligent operation and maintenance system for urban rail transit vehicles from the perspective of the internet of things, using 5g as a technical tool. the fifth generation network technology, as an emerging product of the current internet era, would inevitably receive attention. chettri lalit once pointed out in his research that 5g can play an important role in the internet of things [1]. the powerful functionality of 5g is beyond doubt. dolgui alexandre believed that 5g technology can achieve end-to-end real-time connectivity at a highly refined level, and achieve relevant end-to-end visibility through the internet of things [2]. 5g has been applied in many aspects, and xiao m l’s research attempted to amplify the video power of 5g base stations [3]. siriwardhana yushan believed that 5g technology can be applied to mobile augmented reality applications [4]. the power internet of things is also an industry that requires 5g. tao j s proposed that the power internet of things must be combined with 5g, bringing many advantages to the power internet of things [5]. mao s q also introduced 5g in his research to address the growing computing needs of the power internet of things [6]. through the research of the above scholars, it is evident that 5g has rich diversity. the logistics, manpower delivery, and other aspects of urban transportation are inseparable from transportation, and urban rail transit, as an important part of urban transportation, has always been highly concerned. bešinović nikola once pointed out pointedly that key infrastructure such as transportation and power networks are crucial for the operation of society and the economy [7]. in order to address these issues, abduljabbar rusul proposed that the operation and maintenance of urban rail transit require the use of artificial intelligence algorithms [8]. liu y also believed that with the explosive development of smart cities, green energy management systems have received research and industry attention [9]. among many ideas, the internet of things has attracted people’s attention. zhu f h believed that intelligent transportation systems driven by the internet of things have enormous potential and capabilities, which can make transportation systems efficient, safe, intelligent, reliable, and sustainable [10]. wijethilaka shalitha discussed the possibility of combining the internet of things with many emerging technologies, such as blockchain and artificial intelligence [11]. based on the above research, highly compatible iot technologies are highly likely to provide assistance for vehicle operation and maintenance. 2. basic urban rail transit intelligent operation and maintenance system in order to meet the actual operation and maintenance needs of urban rail transit vehicles, deng b proposed an intelligent operation and maintenance system architecture for urban rail transit, consisting of a hardware system of intelligent detection equipment and facilities and a software system of maintenance and guarantee management mode [12]. under this framework, the operation and maintenance of urban rail transit are subdivided into multiple aspects, or specialties, mainly reflected in vehicles, power supply, and communication. under this clear division of labor, the efficiency of management and operation of intelligent operation and maintenance systems can be mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fully released. guo j w further proposed the establishment of an intelligent operation and maintenance system for urban rail transit vehicles based on full element and full process data fusion [13]. the system has very powerful functions, including intelligent scene management, vehicle maintenance management, vehicle health management, trackside intelligent detection, and intelligent control center for classification and work. it can be said that the versatility of this system effectively solves the problem of vehicle operation and maintenance. based on the new generation of information technology applications, this system can achieve many intelligent application functions, such as condition monitoring, condition evaluation, and proposing maintenance methods for vehicle professional equipment. the system itself also has the function of fault analysis. in this multifunctional environment, the maintenance and support costs of the system can be reduced, as well as the risk of malfunctions, ultimately improving the service life of the equipment. figure 1. design of intelligent operation and maintenance system for urban rail transit vehicles as shown in figure 1, the operation of this intelligent operation and maintenance system for urban rail transit vehicles based on the entire process and all elements mainly relies on various technical means including the internet of things, big data, and artificial intelligence. it would break through the technology of integrating diverse and heterogeneous data of urban rail transit vehicles, and combine the data fusion of the entire process and all data to ultimately output it to the intelligent operation and maintenance platform, making it digital, networked, and intelligent, and implement a new mode of urban rail transit operation and maintenance services. the above is the overall framework of the system, which is further divided into business architecture, technical architecture, and functional architecture. the business architecture mainly consists of operation monitoring, fault detection, and vehicle scheduling, while the technical architecture is divided into monitoring center, decisionmaking center, dispatch center, and support center. the functional architecture is mainly responsible for supporting the business architecture. as shown in figure 2, it is a schematic diagram of the system architecture division of labor. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2. architecture division of intelligent operation and maintenance system for urban rail transit vehicles 3. iot applications based on 5g networks in today’s society, 5g networks are gradually becoming popular and have strong applicability. however, wang w believed that there are some weak links in the compatibility between 5g and current iot services, which still cannot meet the existing communication services [14]. in his research, in order to design a 5g with strong compatibility, he proposed a series of internet technologies, among which sdn (software defined network) integrates multiple network communication technologies to achieve integrated control of all network terminal devices. lu zp also held the same opinion, believing that sdn promotes network innovation and simplifies network management [15]. in addition to sdn, there is also nfv (network functions virtualization). in his research, gong f believed that nfv can inject new impetus into the development of communication network technology [16]. the last key technology, nb iot (narrow band internet of things or cellular internet of things), has also been recognized by other researchers. ma hy proposed that the total scale of global cellular internet of things connections exceeds 2 billion, which has been widely applied [17]. with the supplementation of the above technologies, 5g can be compatible with and used by the internet of things. the following shows the differences in the communication performance of the internet of things with the support of 5g and 4g respectively. table 1. comparison of the effects of 4g and 5g on communication performance terminal type 4g edge iot agency 5g integrated communication gateway downlink rate (mbps) 44.5 893.1 the whole system business architecture technical architecture function architecture operation monitoring fault detect vehicle scheduling monitoring center, decision-making center, dispatch center, support center vehicle health management trackside intelligent detection vehicle maintenance management mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset uplink rata (mbps) 7.8 94.6 network delay (ms) 37.2 18.3 according to table 1, 4g has a downlink rate of only 44.5mbps, which is much lower than 5g’s 893.1mbps. similarly, the downlink rate is only 7.8mbps, which is much better than 5g’s 94.6mbps. in terms of latency, 5g’s 18.3ms is lower than 37.2ms, indicating that 5g is much stronger than 4g in these communication performance indicators. 3.1 a blockchain-based logistics system after the improvement of 5g network, the universality and compatibility of iot technology have made it reusable in other places. ai x y established a logistics system based on 5g iot and blockchain in its research [18]. this system encrypts logistics information in response to recent issues such as drug and food safety, fully leveraging the role of 5g. figure 3. logistics system framework based on blockchain and 5g internet of things as shown in figure 3, the framework can be divided into network layer, smart contract layer, iot platform layer, data layer, and application layer as a whole. first of all, people can see that the data layer and the network layer are closely connected. the data layer contains data signatures and hash function, mainly involving block data, while the network layer connected to it is mainly responsible for the main logic of the blockchain. next is the smart contract layer, which mainly relies on the rcp (remote file copy) module to interact with virtual machines. then there is the iot platform layer, which retrieves iot data information and control instructions based on the database. finally, there is the application layer, which interacts with the smart contract layer and the iot platform layer for information exchange. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3.2 application of 5g internet of things technology in distribution networks figure 4. network extension graph based on 5g as an important link in ensuring electricity consumption in modern society, it is necessary to ensure its efficiency and safety in power transmission. therefore, supervision and management of the distribution network are also essential. the wireless network selection system with 5g base stations can also be seen as a combination of 5g internet of things technology. as shown in figure 4, the wireless network routing system consists of three major systems, namely the terminal layer, communication layer, and main station layer. the terminal layer is mainly composed of wireless radio frequency identification, wireless acquisition units, and wireless aggregation units, while the communication layer is composed of a 5g wireless network core network and a base station, which are interconnected by optical fibers and network cables. finally, there is the main station layer, which basically receives signals from the main station, uploads them to the cloud platform, and finally delivers them to mobile applications. 4. comprehensive calculation during 5g application with the rapid development of wireless communication technology, the use of 5g has become increasingly widespread. in order to allocate resources reasonably, chen f t proposed the noma (non orthogonal multiple access) algorithm [19]. similarly, xiang x y proposed a 5g data encoding algorithm to address the interference of traditional power iot terminal tasks [20]. firstly, the indicator vector of user a is set to η: η η η η={ a1 ， ， a2 …… an} (1) the channel state information matrix is set to a; the channel precoding matrix is set to b; the beamforming signal flag is b; the user’s noise is c, c is the number of terminals in the power iot; α is the number of users, and the signal received by user a is set to ya : α c ya =∑ηan an an aa b b +∑∑a b b can an a + n c∈ a= =1 n 1 (2) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assuming that during the calculation process, the user uses a frequency band with a bandwidth of d, and sets e as the bandwidth channel state and f as the encoding and processing coefficients, then: α c ∑∑ηan an an ana b b f= a= =1 n 1 (3) d after each parameter is determined, the channel capacity g should be calculated as: 2 c 1+ ∑ηaneban g ab d( , ) = ⋅lg( n an 2 ) (4) η c 1+ ∑∑ηanffan a=1 n=1 this algorithm can determine the channel capacity of the power internet of things terminal task access, and can establish a secure communication channel. the security authentication method for task access of power iot terminals based on 5g data algorithm has good anti-interference performance and solves many problems that exist compared to traditional methods. through this method, the bit error rate is lower, the overall anti-interference performance is better, and the practicality is stronger, which can provide a basis for the safe and stable operation of the power internet of things[21]. 5. comparative experimental design based on 5g and ordinary vehicle operation and maintenance systems after the design of the intelligent operation and maintenance system for urban rail transit vehicles based on iot5g technology is completed, this article also needs to conduct experimental analysis of the actual effect of this system. therefore, this article selects two large parking lots in deep bustling areas of a certain city, and sets the vehicle operation and maintenance system in the parking lot as the research carrier. one of them is selected to load the vehicle operation and maintenance system designed in this article, and is set as parking lot 1. the other remains the same and uses a traditional system, set as parking lot 2. then, a certain ten days after using the new system for a period of time and a certain ten days before loading are selected as a comparison to calculate the changes in traffic flow in the two parking lots [22]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5. comparison of traffic flow in two parking lots before loading the new system mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6. comparison of traffic flow between two parking lots after loading the new system in parking lot 1 from figure 5, it can be seen that the traffic flow of the two parking lots before loading the new system is actually similar. within the ten days selected for the experiment, the average traffic flow of parking lot 1 was 275.7 vehicles, and the average traffic flow of parking lot 2 was 273.3 vehicles. from figure 6, it can be seen that with the assistance of the new system, the average traffic flow of parking lot 1 is 305.4 vehicles. in the same ten days, the traffic flow of parking lot 2 has not changed significantly compared to before, only 272.7 vehicles. this indicates that the new system can help with the vehicle operation and maintenance system in the parking lot, allowing for more efficient vehicle operation and maintenance work, with a greater vehicle throughput. at the same time, it can also attract more car owners to come and park with the help of efficient work. 6. conclusions after a series of introductions, system construction, and formula calculations, the idea of this article is basically clear. it is to first demonstrate the process of vehicle operation and maintenance through the basic vehicle intelligent operation and maintenance system, and integrate the operational logic of an intelligent operation and maintenance system. by combining 5g with the internet of things, people can discover the powerful tool of iot5g, because the internet of things is actually based on the internet, allowing any terminal that can be accessed through the network to connect, commonly known as the internet of things. this approach is fully in line with vehicle operation and maintenance and urban rail transit management. then, this article uses the 5g data encoding algorithm as a mathematical tool to establish the underlying logical foundation for the combination of iot-5g and vehicle operation and maintenance. finally, by comparing the new system designed in this article with traditional vehicle operation and maintenance systems, it was found that the assistance of the new system for vehicle operation and maintenance work is much greater than that of traditional systems, which is consistent with the research conclusion of this article. however, the design process of this article is not perfect, and the research days in the experimental section are too few, so the experimental results may not be accurate. in summary, as an important component of urban transportation, urban rail transit and its vehicle operation and maintenance are closely related to urban development. therefore, it would inevitably receive more resources for development and research with high attention. the ideas designed in this article have certain significance, but it is clear that this work would not stop here, and its development prospects are worth looking forward to. references chettri lalit, rabindranath bera. a comprehensive survey on internet of things (iot) toward 5g wireless systems. ieee internet of things journal, 2019, 7(1):16-32 dolgui alexandre, dmitry ivanov. 5g in digital supply chain and operations management: fostering flexibility, end-to-end connectivity and real-time visibility through internet-of-everything. international journal of production research, 2022, 60(2): 442-451 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset xiao m l, du x w, cai l y, yong w. design and implementation of radio frequency power amplifier for 5g communication base station. journal of electronic measurement and instrumentation, 2022, 36(12):244252 siriwardhana yushan, et al. a survey on mobile augmented reality with 5g mobile edge computing: architectures, applications, and technical aspects. ieee communications surveys & tutorials2021, 23(2): 1160-1192 tao j s, et al. the impact of internet of things supported by emerging 5g in power systems: a review. csee journal of power and energy systems, 2019, 6(2): 344-352 mao s q, hong j, ren h, ma x, xu j j. 5g mobile edge computing task unloading method for power internet of things. electrical measurement and instrumentation, 2022, 59(2):105-111 bešinović nikola. resilience in railway transport systems: a literature review and research agenda. transport reviews, 2020, 40(4): 457-478 abduljabbar rusul, et al. applications of artificial intelligence in transport: an overview. sustainability, 2019, 11(1):1-24 liu y, chao y, li j, xie s l, zhang y. intelligent edge computing for iot-based energy management in smart cities. ieee network, 2019, 33(2): 111-117 zhu f h, lv y s, chen y y, wang x, xiong g, wang f y. parallel transportation systems: toward iot-enabled smart urban traffic control and management. ieee transactions on intelligent transportation systems, 2019, 21(10): 4063-4071 wijethilaka shalitha, madhusanka liyanage. survey on network slicing for internet of things realization in 5g networks. ieee communications surveys & tutorials, 2021, 23(2): 957-994 deng b, xu j j, gao j, zhu j w. analysis of monitoring content for intelligent operation and maintenance construction of urban rail transit. information technology, 2022, 51(3):4-11 guo j w, si j m, zhao m l, zhang l y. intelligent operation and maintenance system for urban rail transit vehicles based on full element and full process data fusion. urban mass transit, 2022, 25(1):210-215 wang w. internet of things communication technology and challenges based on 5g network. internet communication, 2022, 24(22):13-15 lu z p, chen f c, cheng g z. design and implementation of the controller scheduling-time in sdn. chinese journal of network and information security, 2018, 4(1):36-44 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 2; march april 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gong f, cheng w b. development status and challenges of network functions virtualization. industrialization, 2018, 8(6):45-50 ma h y, zhou w, fu y, shao y p, li d. discussion on the evolution of architecture of the core network of cellular internet of things. journal of electronics and information technology, 2022, 44(9):8 ai x y, traceability and abnormal data warning system based on blockchain and 5g internet of things. electronic design engineering, 2020, 28(10):108-112 chen f t, tang c, liu y f. energy efficiency optimization based on noma iot communication. communication and network, 2018, 44(7):117-121 xiang x y. research on task access security authentication of power internet of things terminal based on 5g data coding algorithm. network & communication technology, 2023, 45(1):81-83 lv, zhihan, liang qiao, and sun you. "6g-enabled network in box for internet of connected vehicles." ieee transactions on intelligent transportation systems (2020). reddy, m. r., srinivasa, k. g., and reddy, b. e. 2018. "smart vehicular system based on the internet of things" journal of organizational and end user computing (30:3), pp. 45-62. mailto:topacademicjournals@gmail.com microsoft word 1032.docx academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset effect of local bio-fertilizers on growth and nutrient content of phaseolus aureus, spinacia oleracea and ocimum sanctum akash krishna murthy, sai krishna reddy and ravi teja department of biochemistry& bioinformatics, institute of science, gitam university, visakhapatnam 530 045, india abstract: india is a major producer and consumer of pulses, but the country's pulse productivity is low. this is due to a number of factors, including nutrient depletion of soils, lack of crop diversification, and pests and diseases. this paper reviews the factors that are limiting pulse productivity in india and discusses some of the potential solutions. keywords: pulses, productivity, india, soil nutrients, crop diversification, pests and diseases 1. introduction plants are the source of raw materials for the food, clothing and shelter.these green plants have also provided all the medicaments and health care needs to man and his domestic animals ever since the advent of civilization. india is one of the ancient countries in the world growing wide range of pulse crops as prime source of protein. further, india is the leading country in pulse cultivation area and contributes 25, 27% of the world production and consumption respectively but also the largest importer of pulses with the contribution of 34% of the global food use (faostat, 2008).india shares 70% of the total world black gram and green gram (vignaradiata) production (faostat, 2008, elzebroek et al., 2008) over the last four decades the country is struggling to increase the area, production and most importantly the productivity, despite rapid growth in cereals (ministry of agriculture, 2008). since the beginning of green revolution, greater importance was given to cereals which led to rapid growth in production and productivity of cereals and almost quite reverse in pulse crops. as a result, the national average pulse productivity (638 kg hag1) declined far below than the global average of 857 kg hag1. consequently, per capita availability of pulses declined from 60.7 to 29.4 g dayg1 during 1951 to 2007 (ministry of agriculture, 2008)against world health organization (who) recommended level of 80 g dayg1 (fao, 2007). international plant nutrition institute has confirmed that indian soils are under nutrient crisis and also concluded that in the absence of nutrient recycling “it is likely that the nutrient balance sheet of indian agriculture will continue to be negative” (tamil nadu agricultural university, 2009).this situation urges the need to improve soil nutrients and pulse productivity. kalmegh, ashwagandha and tulsi are important medicinal plants mentioned in ancient ayurvedic literature. these medicinal plants are used in various drugs in curing fever to acute jaundice. the irregular and low germination is the main problem in the propagation of many medicinal plants (koppad et al., 2006). this can be corrected and enhanced by application of bio-fertilizers.bio-fertilizers application in medicinal plants production in sustainable agriculture with aim of remove or reduce the chemical input in order to reach to quality increasing mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and sustainability of yield is very important(sharma et al., 2002). usage of correct nutrition by bio-fertilizers, will obtain quantitative and qualitative yield maximum from medicinal plants such as basil. green vegetables are a major source of iron and calcium for any diet. green vegetables are rich in vitamins, and also improve immune function. they are useful in reducing the risk of cancer and heart disease since they are low in fat, high in dietary fiber, and rich in folic acid, vitamin c, potassium and magnesium, as well as containing a host of phytochemicals, such as lutein, β-cryptoxanthin, zeaxanthin and β-carotene. growthimprovement and quality improvement of green vegetables is very necessary because it is used for the treatment of many diseases. to avoid the residual toxicity of chemical fertilizers, it is always advisable to raise these vegetables through organic cultivation practices. the use of bio-fertilizers has been reported to be beneficial for the cultivation of vegetable and cereals by many workers (kapoor et al., 2004, mehrotra et al., 1971, mehrotra et al., 1979, venkateswarlu et al., 1983, hadas et al., 1987). the amounts of active principles are depending on total biomass yield which is further depends on the climatic feature, method of agro-techniques, water management and also fertilizer applications. so yield improvement can be achieved by standardizing the agronomy especially with respect to those parameters. the use of organic amendments and its practices improves soil structure, physical properties and especially its water holding capacity (abiven et al., 2009) which could be the great asset in tropics and for its sustainability. the present investigation was undertaken to study the effect of commercial bio-fertilizers on micronutrient content, morphological and biochemical parameters in three divergent groups of plants belonging to pulses, vegetable and medicinal categories. 2. materials and methods 2.1 selected bio-fertilizers and plants two commercial bio-fertilizersvia annapurna and navajeevan were used. bio-fertilizers-annapurna: contains azotobacter, azospirillum, neem, phosphate solubilizing bacteria, castor and trichoderma. bio-fertilizers-navajeevan: contains bio extract, organic fertilizer, and sea weed amino acids. three different plants were selected for the present study. those are 1) a pulse plant-phaseolus aureus 2) a leafy vegetable-spinaciaoleracea and 3) a medicinal plant-ocimum sanctum 2.2 soil amendments: earthen pots, 20-cm diameter and 30-cm depth, were filled with 5 kg soil. soil was amended either with annapurna bio-fertilizer or navajeevan fertilizers. the soil mixture was prepared by combining the commercial bio-fertilizer and soil in a ratio of 1:1. both the fertilizers were mixed 3days prior to sowing. all pots were irrigated with tap water and left for organic material decomposition. 2.3 treatments and experimental design: there were three treatments, with three replicates, for each of the three soil amendment systems. these were i) control-soil without bio-fertilizer ii) soil with annapurna bio-fertilizer and iii) soil with navajeevan biofertilizer. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset pots were arranged on a bench in a wire-netting greenhouse under natural environmental conditions. 2.4 harvesting: observations were recorded after 1day, 15 days, 30 days, 45 days and 60days after sowing. morphological parameters such as shoot length, root length and total leaf area were calculated. the number of seeds germinated in each concentration was counted on 7thday and the germination percentage was calculated by using the following formula no. of seeds germinated germination percentage = -------------------------------× 100 total no. of seeds sown the leaf area was calculated by measuring the length and breadth of the leaf as described below leaf area (cm2) = k × length × breadth where, k = kemp’s constant (for dicot leaves = 0.66). 2.5 estimation of protein: protein content was determined by the method of lowry et al., (lowry et al., 1951) 0.5 g of plant sample (shoot) was homogenized in 10 ml of 0.1m phosphate buffer and the homogenate was centrifuged at 3000rpm for 10 minutes. 0.5 ml of the supernatant was taken in a test tube and volume is made upto 1ml with distilled water. then 5 ml of reagent ‘c’ (protein reagent) was added. this solution was mixed well and kept in dark for 10 minutes. later, 0.5 ml of folinciocalteau reagent was added and the mixture was kept in dark for 30 minutes. the sample was read at 660 nm in the colorimeter. 2.6 estimation of total sugar content: the total sugar content was determined by the anthrone reagent method (hodge et al., 1962). 100mg of the sample was weighed and hydrolyzed by keeping in boiling water bath for 3 hours with 5ml of 2.5n hcl and cooled to room temperature. later it was neutralized with solid sodium carbonate until the effervescence ceased. the volume was made upto 100ml and centrifuged. 0.5 and 1ml aliquots of the supernatant were taken for analysis. the anthrone reagent was prepared right before analysis by dissolving 0.2 g of anthrone (0.2%) in concentrated sulfuric acid, protected from light and used within 12 h. anthrone reagent (4.0 ml) was added cautiously to each tube containing 1.0 ml of standard solutions of glucose (10 – 100 µg/ml) and test solution. tubes were then placed at 50c for 10 min. subsequently, tubes were boiled for 5 min on constant boiling water bath. after heating, the tubes were allowed to cool at room temperature for 15 min. later absorbance was measured at 620 nm in colorimeter against reagent blank. 2.7 estimation of fat: fat content was determined by chloroform-methanol method. 0.2gm of sample was weighed into screw capped tubes. 10ml of chloroform-methanol (2:1) was added and vortex for 3mins (extracts the fat into organic layer). the tubes were kept in a cold room overnight. the organic layer is taken into another empty weighed beaker. the beakers are incubated at 60oc, overnight and weighed after incubation. fat content was estimated using the difference in the weight of the beaker before and after solvent extraction. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.8 nitrogen analysis: total nitrogen in plants is estimated by the kjeldahl method (jackson, 1956,). in plants, n is present in protein form, and digestion of the sample was carried out with h2so4 containing digestion mixture (10 parts potassium sulphate and 1 part copper sulphate). sample size of 0.5-1.0 g depending on the type of crop and the plant part was taken. the procedure involves sample digestion, distillation and estimation of nitrogen. 2.9 analytical methods 2.9.1 dry ashing high-temperature oxidation destroys the organic matter. the plant sample is ashed at 500–600 °c by placing 3.0 g of the sample in a silica crucible and heated in a muffle furnace for 4–6 hours. the ash residue was dissolved in dilute hcl, filtered through acid-washed filter paper, and the volume is made up to 100 ml in a volumetric flask. the estimation of micronutrients was carried out in the dry-ashed sample solution by atomic absorption spectrophotometer (aas gbc-932plus). dry ashing is a preferred method for the analysis of fe, zn, cu, mn and other trace elements. 2.9.2 polyacrylamide gel electrophoresis (page): the page gel was carried out according to the modified method of laemmli (laemmli, 1970). this discontinuous gel system used a 15.0 cm x 14.0 cm gel containing 12% separating gel and 4% stacking gel. 20% (v/v) of sample buffer (0.5 m tris-hcl ph 6.8, 20% (v/v) glycerol, 0.05% (w/v) bromophenol blue was added to the leaf extracts. a total volume of 20µl protein extract solution was loaded into each well and electrophoresis was carried out at 100v until the bromophenol blue dye reaches the bottom of the gel. after the electrophoretic separation, the gel was stained with coomassie brilliant blue and bands are observed. 3. results and discussion in this investigation two commercial bio-fertilizerswere used to see the effect on the morphological parameters of growth and yield of green gram, spinach and tulsi plants. the results so obtained are described as under. from 10 randomly selected plants average data has been obtained. the treated plants have been found to have highest increase in all the parameters, than that with the control. plants treated with annapurna bio-fertilizer have been shown to have fastest growth rate as compared to other treatment and control plants. 3.1. germination: the germination and seedling parameters of plants tested were furnished in table 1. there were significant differences in germination per cent. table 1: germination percentage (%) s. no. name of the plant soil soil + annapurna soil + navajeevan 1. green gram 60.15% 71.72% 70.38% 2. spinach 70.1% 80.16% 70.38% 3. basil 50.34% 60.13% 60.21% the spinach recorded higher germination percentage (80.16) followed by green gram (71.72 %) and the least was in tulsi (60.13 %) in annapurna treated plants. germination in navajeevan treated plants showed that spinach mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and green gram were on par with each other followed by tulsi. significant differences were noticed in germination due to bio-fertilizers. the germination per cent did not vary much due to the interaction between medicinal plants and bio-fertilizers. however, in tulsi navajeevan treated soil (60.21%) recorded germination on par with annapurna (60.13%) and the least was in control (50.34%). the probable reason is the relative enhancement of germination might be attributed to the role of phosphorous solubilizing bacteria; n2 and azospirillum enhance the metabolic activity in germinating seeds thus, resulted in early and higher seed germination.this may be due to its better adaptation to acidic soil conditions and higher n fixing as well as phytohormone producing ability. hence, it will be advantageous to use this type of bio-fertilizer for large-scale production of pulses and vegetables. present investigation findings are in conformity with results of vijayakumari,janardhananin ceibapentandra(vijayakumari and janardhanan, 2003)and koppad,umarbhadshain ocimum sanctum (koppad and umarbhadsha, 2006a). 3.2. shoot and root length: the shoot and root lengths were measured at 15 days’ time intervals for green gram, spinach and tulsi and are presented in tables 2 and 3. a gradual increase in these growth parameters was observed. table 2: shoot length after sowing seeds at an interval of 15 days (in cm) sample 1 day 15 days 30days 45 days 60 days soil green gram 0 3.1 6.2 12.2 20 soil + annapurna green gram 0 5.2 8.5 15 25 soil + navajeevan green gram 0 3.5 6.5 13 21 soil spinach 0 4 8.9 15.6 25 soil + annapurna spinach 0 5.3 9 17 31 soil + navajeevan spinach 0 4 8.4 17 28 soil basil 0 1.8 8.2 15 23.5 soil + annapurna basil 0 3 8.5 16 28 soil + navajeevan basil 0 2 8.2 15.7 25 the higher shoot and root lengths were recorded in annapurna soil mixture of the three plants. spinach recorded higher shoot length of 31.26 cm followed by tulsi(28.1cm) and then green gram(25.2cm).these results are corroborate with present findings of ponnuswamy (ponnuswamy, 1993) and vanagamudiet al., in neem(vanangamudi et al., 1993). table 3: root length after sowing seeds at an interval of 15 days (in cm) sample 1 day 15 days 30days 45 days 60 days soil green gram 0 1.5 2.2 5.7 8.0 soil + annapurna green gram 0 1.9 2.2 6.3 8.2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset soil + navajeevan green gram 0 1.7 2.3 7.0 8.3 soil spinach 0 1.2 1.5 2.0 2.5 soil + annapurna spinach 0 1.5 1.8 2.1 2.9 soil + navajeevan spinach 0 1.5 1.7 2.1 2.7 soil basil 0 2.5 5.1 7.2 8.5 soil + annapurna basil 0 2.8 5.7 7.6 9.0 soil + navajeevan basil 0 2.8 5.5 7.1 8.5 there was significant difference in root length of annapurna treated tulsi (9.1cms) when compared to other treatments. treatments viz., navajeevan treated soil and control are on par with each other (8.2cms). the improvement of root length due to combined bio-fertilizer inoculation in tree legumes (delacruzet al., 1988) is in agreement with the results of the present study. the same findings were reported due to effluent treatment in green gram by kumar and bhargava (kumar and bhargava, 1998). the root length did not show any significant difference among the plants. the application of bio-fertilizers had no significant variation in all the treatments. 3.3. leaf area: the leaf area was measured at 15 days’ time interval for green gram, spinach and tulsi, parameters was represented in table 4. table 4: leaf area after sowing seeds at an interval of 15 days (in cm2) sample 1day 15 days 30 days 45 days 60 days soil green gram 0 0.99 2.97 3.3 4.62 soil + annapurna green gram 0 1.32 3.15 4.35 5.77 soil + navajeevan green gram 0 1.18 2.64 .3.96 4.95 soil spinach 0 1.32 10.56 27.72 36.96 soil + annapurna spinach 0 3.66 19.8 36.96 52.8 soil + navajeevan spinach 0 3.66 16.5 32.34 47.52 soil basil 0 0 0.99 1.32 4.62 soil + annapurna basil 0 0 1.98 3.96 5.28 soil + navajeevan basil 0 0 1.32 2.64 4.62 annapurna fertilizer treated plants have been found to have highest leaf size. the average increase in leaf size than that of control in case of spinach plants is found to be equal to 42.8 %, whereas average increase in case of tulsi plants having treatment (annapurna)have been shown to increase by50%. an increase of 24.9% was observed in green gram. greater increase in leaf area increases the chances of yield of active principles in case of medicinal plants and a close increase in spinach gives better yield of foliage. the increase in shoot length, root length, and total leaf area were recorded in annapurnabio-fertilizer soil mixture. it may be the presence of microorganisms like phosphate solubilizing bacteria, fungal inoculants in the biomailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fertilizer. soil organism tends to increase the oxygen concentration. the soil becomes looser and opens the pores of the soil causing more aeration and increasing the growth of the plant. 3.4. biochemical parameters: the plants grown in annapurna bio-fertilizer treated soil recorded higher protein yield compared to other individual treatments. this result emphasizes n2 nutrition for increased protein yield (dhage et al., 1984). there was an increase of 54.8% protein in 60d old green gram plants as against the control. the highest yield could be of p and n respectively andattributed to enhance supply of n and p, production of phytohormones and better portioning of dry matter into the economic (dhage et al., 1984, rudresh et al., 2005). selvakumaret al.,(selvakumar et al., 2009) concluded that n and p nutrition is vital and the trend of variation in protein content was similar to that of n and p. similar reports of increase in yield attributes, grain yield, total plant dry matter weight (tdm) and protein content were reported when biofertilizers and organic manures applied together(selvakumar et al., 2009, uyanöz, 2007, gomma, 2007). similar results were obtained for carbohydrate and fat analysis as shown in figure1 & 2. figure 1: effect of fertilizer on carbohydrate content carbohydrate content was estimated using anthrone method after 30 days and 60 days of sowing seeds. figure 2: effect of fertilizer on fat content after 30 days after 60 days mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset as shown in fig 3 it is clearly evident that the annapurna biofertilizer is enhancing the protein content in green gram when compared with soil without fertilizer. figure 3: polyacrylamide gel electrophoresis 1 2 3 1. navajeevan green gram 2. annapurna green gram 3. soil green gram even on protein profiling, the result showed that annapurna samples have high protein content. the results (fig 4) showed that the amount of nitrogen content increased irrespective of treatments. the magnitude of such changes, however; varied with treatments, being highest nitrogen content (7.3 g kg-1) in the annapurna treated plants which was closely followed by the navajeevan. such increase in nitrogen content might be due to azotobacter, psb and azospirillum causing relatively greater utilization of available nitrogen by plants. figure 4: percent nitrogen content percent of nitrogen content was estimated by kjeldahl method after 30 days and 60 days of sowing seeds. 3.5 micronutrients content in plants: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: micronutrient content after 30days of sowing figure 6: micronutrient content after 60days of sowing zinc iron copper the results (fig 5, 6) show that basil has recorded highest zn content which is followed by spinach and then green gram. the concentration of zn was highest (80ppm) in basil leaves, which is in correlation with findings of bhowmiket al., (bhowmiket al., 2008). zinc plays a vital role in human health so the higher concentrations of zinc enhance medicinal value for which it is known. similarly spinach exhibited high concentration of fe content mainly in the annapurna sample which is followed by the green gram and basil. there was an increase of ~ 30% of iron content in spinach which shows an increase of micronutrient content of this leafy vegetable. cu content is mostly present in traces and no drastic increase of metal ion by the addition of biofertilizers. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset azotobacteriaone of the ingredients of annapurna bio-fertilizer synthesizes auxins, cytokinins, and ga–like substances, and these growth materials are the primary substances controlling the enhanced growth. these hormonal substances, which originate from the rhizosphere or root surface, affect the growth of associated plants. in order to guarantee the high effectiveness of inoculants and microbiological fertilizers it is necessary to find the compatible partners, i.e. a particular plant genotype and a particular azotobacter strain that will form a good association. the strain used in this fertilizer is compatible with spinach followed by green gram and basil.soildwelling diazotrophs such as azotobacter are especially useful in gauging the health and virility of the ground. azospirillum can positively influence plant growth, crop yields and n-content of the plant. this plant stimulatory effect exerted by azospirillum has been attributed to several mechanisms, including biological nitrogen fixation and auxin production.azospirillum inoculation alters root morphology, which has been ascribed to the bacterial production of plant growth regulating substances (oda and jos, 2000). an increased number of lateral roots and root hairs enlarges the root surface available for nutrients. this results in a higher nutrient uptake by inoculated roots and an improved water status of the plant, which in turn could be the main factor enhancing plant growth. trichoderma sps. are free-living fungi that are common in soil and root ecosystems. some are opportunistic, avirulent plant symbionts, as well as being parasites of other fungi. at least some strains establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. they produce or release a variety of compounds that induce localized or systemic resistance responses. these root– microorganism associations cause substantial changes to the plant proteome and metabolism (gary et al., 2004). root colonization by trichoderma spp. also frequently enhances root growth and development, crop productivity, resistance to abiotic stresses and the uptake and use of nutrients.trichoderma strains playan important role in the bioremediation of soil thatare contaminated with pesticides and herbicides.they have the ability to degrade a wide range ofinsecticides: organochlorines, organophosphatesand carbonates. this was clearly evidenced by better growth parameters and nutrient content in annapurna fed plants which contains trichoderma as one of the ingredient. 4. conclusion the various observations and results obtained from the above study of the effect of two different commercial biofertilizers on the morphological, biochemical and nutrient parameters is beneficial and increased the yields. howeverbest results were obtained in the treatment of annapurna bio-fertilizer in all plants under study i.e., green gram, spinach and basil (pulse crop, vegetable and medicinal plant respectively). this may be due to co-operative microbial activities in the root and soil environment benefiting the plant growth and health and also soil quality.azotobacter, azospirrillum, phosphate solubilizing bacteria and trichoderma present in the annapurna biofertilizerplayed a vital role in enhancing germination, vegetative growth parameters, mineral content and soil quality which are not supplemented in navajeevan bio-fertilizer. soil microorganisms play an important role in increasing the food quality and sustaining environmental quality from the ecological and agricultural perspectives. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset acknowledgements authors are grateful to regional sugar cane research institute, angrau, anakapalle (ap), for kind cooperation and help in providing aas for analyzing plant samples. we are also thankful to gitam institute of science, gitam university for providing necessary laboratory facilities to carry out this work. references abiven, s.,menasseri, s.,chenu, c. (2009).theeffects of organic inputs over time on soil aggregate stability – a literature analysis, soil biology and biochemistry. 41, 1–12. bhowmik,s., chowdhury, s.d.,kabir,m.h., ali, m.a. (2008). chemical composition of some medicinal plant products of indigenous origin, bangladesh veterinarian. 25, 32-39. delacruz, r.e., manalo, m.q.,aggangan,n.s., ambalo, j.d.t. (1988) growth of three legumes trees inoculated with vam fungi and rhizobium, plant soil. 108, 111-15. dewan,g.i., rao, n.s.s. (1979). seed inoculation with azospirillum brasilense and azotobacter chroococcum on the root biomass of rice (oryza sativa), plant soil. 53, 295-300. dhage, a.r.,patil,n.d., kadam, s.s. (1984). effects of n and p fertilization on yield and composition of black gram (vignamungo l. hepper) seeds, plant soil. 81, 441-444. elzebroek,t., wind,k. guide to cultivated plants. (2008). cab international, united kingdom, 262. fao, (2007) protein and amino acid requirements in human nutrition, report of a joint who/fao/unu expert consultation, (who) technical report series, geneva, switzerland, pp. 935. faostat (2008). food and agriculture organization of united nations (fao), http:// faostat.fao.org/ site/339/ default.aspx. gary harman,e., charles howell,r., ada viterbo, ilan chet and matteo lorito (2004).trichoderma species — opportunistic, avirulent plant symbionts, nature reviews microbiology. 2, 43-56 gomma,a.m., mohamed, m.h. (2007). application of bio-organic agriculture and its effect on guar (cyamopsistetragonoloba l.) root nodules, forage, seed yield and yield quality, world journal of agriculture science. 3,91-96. hadas,r., okon,y. (1987). effect of azospirillum brasilense inoculation on root morphology and respiration of tomato seedlings, biological fertility of soil. 5, 241-47. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset hodge, j.e. and hofreiter, b.t. (1962). in: methods in carbohydrate chemistry, (eds. whistler, rl, be miller jn), academic press, new york. jackson,m. l.(1956) soil chemical analysis, prentice-hall, inc. kapoor, r., giri,b., mukerji,k.g.(2004). improved growth and essential oil yield and quality in foeniculumvulgare mill on mycorrhizal inoculation supplemented with p-fertilizer, bioresource technology. 93, 307-311. koppad,a.g., umarbhadshan.k. (2006). effect of pre-sowing treatments on seed germination of babehi and senna in nursery, karnataka journal of agriculture science. 19, 441 – 442. koppad,a.g., umarbhadsha, n.k. (2006a) effect of pre-sowing treatments on seed germination of laving tulsi and white tulsi in nursery beds, karnataka journal of agriculture science. 19,443–444. kumar, r., bhargava, a.k. (1998). effect of sugar mill effluent on the vegetative growth and yield of triticumaestivum, advances in plant sciences. 11, 221-227. laemmli, u.k.(1970). cleavage of structural proteins during the assembly of the head of bacteriophage t4. nature. 227, 680–685. lowry,o.h., rosebrough,n.j., farr,a.f., randall, r.j. (1951). protein measurement with the folinphenol reagent, journal of biological chemistry. 193, 265-275. mehrotra,c.i., lehri, l.k.(1971). effect of azotobacter inoculation on crop yields, journal of indian society soil science. 19, 243-48. ministry of agriculture, government of india, department of agricultural and cooperation, directorate of economics and statistics: agricultural statistics at a glance (2008) (http:// dacnet.nic.in/ eands/ latest_2006.html). odasteenhoudt, jos vanderleyden(2000).azospirillum, a free-living nitrogen-fixing bacterium closelyassociated with grasses: genetic, biochemical and ecological aspects, fems microbiology reviews. 24, 487506. ponnuswamy, a.s. (1993).seed technological studies in neem. m.sc. thesis, tamil nadu agriculture university, coimbotore (india). rudresh, d.l.,shivaprakash, m.k., prasad, r.d.(2005). effect of combined application of rhizobium, phosphate solubilizing bacterium and trichoderma spp. on growth, nutrient uptake and yield of chickpea (ciceraritenium l.), applied soil ecology 28, 139-146. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset selvakumar,g., lenin,m., thamizhiniyan,p., ravimycin,t. (2009). response of biofertilizers on the growth and yield of black gram, recent research science technology. 1, 169-175. sharma,a.k. (2002a)biofertilizers for sustainable agriculture, agrobios, india, , 407. tamil nadu agricultural university, (2009). department of agricultural meteorology (http:// www.tnau.ac.in/scms/agmet/weather.html). uyanöz, r. (2007). the effects of different bio-organic, chemical fertilizers and their combination on yield, macro and micro nutrition content of dry bean (phaseolus vulgaris l.), international journal of agriculture research. 2, 115-125. vanangamudi, k.,padmavathi, s.,manonmani,v., surendran, c. (1993) effect of pelleting with biofertilizers, biocids and nutrients on the viability and vigour of neem seeds. paper presented in: international world neem conference, bangalore, , feb. 24–28, p.64. venkateswarlu,b., rao, a.v. (1983). response of pearl millet to inoculation with different strains of azospirillum brasilense, plant soil. 74, 379-86. vijayakumari,b., janardhanan, k.(2003). effect of biofertilizer on seed germination, seedling growth and biochemical changes in silk cotton (ceibapentandra), crop research. 25, 328-332. mailto:topacademicjournals@gmail.com microsoft word 1028.doc academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset evolutionary insights: comparative analysis of porphyrin and chlorophyll metabolism maría carmen garcía rodríguez, javier antonio pérez martínez and laura isabel fernández lópez department of plant biology i plant physiology, faculty of biology, complutense university of madrid spain abstract: metabolic pathways represent intricate sequences of enzymatic reactions that underpin the remarkable phenomenon of cellular metabolism. this metabolic process, like all biological phenomena, has evolved over time, resulting in the diverse array of metabolic pathways found in living organisms. to unravel the evolutionary history of metabolism, comparative analyses of its constituent elements are essential. in this abstract, we explore the significance of comparative studies in reconstructing the evolutionary history of metabolism, highlighting the pioneering work of cunchillos and lecointre (2002, 2003, and 2005) in this domain. keywords: metabolic pathways, cellular metabolism, evolutionary history, comparative analysis, enzymatic reactions 1. introduction: a look back in time metabolic pathways are a series of successive biochemical reactions catalyzed by enzymes which together constitute a process of extraordinary complexity, cellular metabolism. like any other biological phenomenon, metabolism is the result of evolution. as the history of the species and their family relationships are derived from comparative studies, the history of metabolism can only be reconstructed through comparative analysis of its elements (cunchillos and lecointre, 2002, 2003, 2005). using the cladistic analysis to build an evolutionary hypothesis of the emergence and evolution of porphyrin and chlorophyll metabolism involves considering photosynthesis from the evolutionary point of view. on the origin of photosynthesis there are basically two hypotheses (olson, 1999, 2001): one suggests that it originated in the prebiotic atmosphere of the earth and comes to life; another, based on recent molecular phylogenetic analysis suggests that photosynthesis arose after chemolithotrophs organisms appear. however, we know little about how they were incorporated into the photosynthetic process its multiple biochemical components. the scientific community agrees that photosynthesis is a process that originates in bacteria because, firstly, there is no archaea with mg-tetrapyrroles based photosystems and, secondly, photosynthetic eukaryota acquired this ability from cyanobacteria through endosymbiosis. it is possible to achieve a better understanding of the evolution of photosynthesis comparatively studying genes or gene products of photosynthesis in the groups of bacteria that synthesize photosystems: purple bacteria (proteobacteria, with photosystem ii), green non-sulfur bacteria (photosystem ii) , green sulfur bacteria (photosystem i), heliobacterias (photosystem i) and cyanobacteria (photosystems i and ii). the earth is about 4,500 million years and the beginning of life is in the archean period, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset about 3800-4000 million years ago. stromatolites (the oldest archaean fossils) containing evidence of biological carbon fixation have an approximate age of 3,800 million years (schidiowski, 1988) while the oldest cyanobacteria-like cell microfossils have an age of 3,500 million years (schopf, 1993; schopf and packer 1987), ie, appearing 300 million years after the first record of life. however, earth was dominated at first by cyanobacteria which were 2,700 million years ago, coinciding with the first appearance of oxygen on earth (des marais, 2000). during approximately 1 million years, cyanobacteria increased the oxygen level to almost a quarter of the current level. the success of these organisms could be due not only to the power advantage of photosynthesis but due also to inhibition by oxygen (as toxicant) of potential competitors. the emergence of the first eukaryotes occurred about 1,800 million years ago, a fact that required 600-800 million years for cyanobacteria were incorporated by endosymbiosis in eukaryotes and evolved into chloroplasts. thereafter the algae increased the oxygen level until present. finally, his descendants land plants appeared 500 million years ago. there is general consensus on the hypothesis suggesting the evolution of photosynthetic pigments from chemoautotrophs: they lived in an environment of chemical imbalance that led to the ability to use the pigments to harness light as an additional source of energy. established photosynthesis, this might evolve to allow cells use sunlight as the only energy source (nisbert and sleep, 2001). on this tour it must be some intermediate stage that could be starring by purple bacteria: the anoxygenic photosynthesis bacteria evolve from this group who had phototaxis by infrared light (nisbert et al., 1995). this hypothesis is based on the close relationship between the emission spectrum of geothermal light and absorption spectrum of bacteriochlorophylls b, relationship that serves the authors to raise the possibility that photosynthesis arose in organisms presenting bacteriochlorophylls a or b. they lived in the vicinity of oceanic hydrothermal vents where they could detect a faint infrared radiation. accordingly, these phototaxis bacteria with the ability to detect infrared light have lived in an optimum environment which would have been an evolutionary advantage in terms of competition for resources or nutrients. subsequently adaptation of this primitive photosystem would have allowed organisms to start using the far-red sunlight as it moved into shallower waters. over time, chlorophylls appear to use light of higher energy (visible) and water photolysis. photosynthesis in bacteria and plants occurs in two phases, photochemistry, and biochemistry. photochemical phase involves the participation of photosynthetic pigments including chlorophylls and bacteriochlorophylls of bacteria and plants which are derived from the porphyrin metabolism. 2. map of metabolism of porphyrins and chlorophylls porphyrins are tetrapyrroles binds covalently to a metal: iron (fe) to form cytochromes, peroxidase, catalase, myoglobin and hemoglobin; copper (cu) or nickel (ni) to form molecules for electron transport in methanogenic bacteria; magnesium (mg) to form chlorophylls and bacteriochlorophylls. in the porphyrin biosynthesis pathway (fig. 1) there are two stages: 1) synthesis of 5-aminolevulinate (ala): in all photosynthetic eukaryota and prokaryota, except the αproteobacteria, ala is synthesized from glutamate which binds glutamyl-trna by glutamyltrna synthase mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset catalyzed reaction (glurs). moreover, all non-photosynthetic eukaryota (animals, fungi and apicomplexa) and αproteobacteria form ala by condensing glycine and succinyl-coa in a reaction catalyzed by ala synthase. 2) synthesis of protoporphyrin ix from 5-aminolevulinate (ala), a chain of six reactions, the same in all organisms figure 1: porphyrins and chlrophylls biosynthesis pathway (modified from genomenet) (red arrows indicate enzymes that undergo a single change in the analysis) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in the context of evolution it is important to highlight the conceptual difference between "evolution of photosynthesis" and "evolution of photosynthetic organisms": the evolution of photosynthesis involves a limited number of genes and / or gene products while the evolution of photosynthetic organisms involves the complete genome. the phylogeny of the 16s subunit rrna (woese, 1987) establishes three domains: archaea (archaebacteria), bacteria (eubacteria) and eucarya (eukaryotes). although this classification was discussed by other authors (cavaliersmith, 1992), the fact is that other phylogenetic studies using new genomic and sequence data provide consistent results with all three domains. however, when phylogeny based on vertical inheritance genes (16s rrna) and photosynthesis gene phylogenies are compared, inconsistencies appear showing that the former do not necessarily reflect the second: evolution of organisms versus evolution of genes. 3. cladistic analysis to approach the evolution of porphyrins metabolism for the comparative study of various types of entities (molecules, metabolism, organs, organisms, populations, behaviors, geographic distribution, ecosystems) different techniques are used all aimed at analyzing the similarity between the strains under study. between different procedures, cladistic analysis provides a high degree of objectivity to study but all techniques provide useful and necessary information in the evolutionary context. the porphyrins and chlorophyll metabolism is a complex process involving numerous chemical reactions catalyzed by enzymes. its structure (components and functions) in the diversity of organisms is a product of evolution and can only be reconstructed by comparing the components. tetrapyrroles serve as electron carriers in all domains of life. heme carrying proteins were postulated to have been present in the last common ancestor of bacteria and archaea. the application of the comparative method requires first determine the set of elements to compare. these elements are referred to as cladistic terminology "operational taxonomic units". they can refer to molecules or species, taxa in general. in this particular case, the set of taxa to be compared is the metabolism of porphyrins and chlorophylls in a set of organisms that constitute the study group (table 1). taxon, that is, each organism metabolism study group, is defined by characters that are enzymes (table 2) involved in this part of cellular metabolism (fg.1). enzymes can be present or absent in a particular taxon (the bchl gene is absent in archaebacteria and present in bacteria) which means that the same character may have different "versions" which are called "character state". table 1: study group, metabolism of porphyrins and chlorophylls in 63 species acronym name of the species domain group afu archaeoglobus fulgidus archaea euryarchaea ago ashbya gossypii eukarya fungi ana nostoc bacteria cyanobacteria ape aeropyrum pernix archaea crenarchaea ath arabidopsis thaliana eukarya plant atu agrobacterium fabrum bacteria -proteobacteria bja bradyrhizobium diazoefficiens bacteria -proteobacteria mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bsu bacillus subtilis bacteria firmicutes buc buchnera aphidicola bacteria -proteobacteria cac clostridium acetobutylicum bacteria firmicutes cal candida albicans eukarya fungi cau chloroflexus aurantiacus bacteria chloroflexi cch chlorobium chlorochromatii bacteria chlorobi cel caenorhabditis elegans eukarya metazoa cho cryptosporidium hominis eukarya alveolata cme cyanidioschyzon merolae eukarya rodofite cne cryptococcus neoformans eukarya fungi cte chlorobium tepidum bacteria chlorobi ddi dictyostelium discoideum eukarya amebozoa det dehalococcoides mccartyi bacteria chloroflexi dge deinococcus geothermalis bacteria deinococus dme drosophila melanogaster eukarya metazoa eco escherichia coli bacteria -proteobacteria gox gluconobacter oxydans bacteria -proteobacteria gvi gloeobacter violaceus bacteria cyanobacteria hal halobacterium sp. nrc-1 archaea euryarchaea hbu hyperthermus butylicus archaea crenarcheae hin haemophilus influenzae bacteria -proteobacteria lic leptospira interrogans bacteria spirochetae lpf legionella pneumophila bacteria -proteobacteria mac methanosarcina acetivorans archaea euryarchaea mca methylococcus capsulatus bacteria -proteobacteria mga mycoplasma gallisepticum bacteria mollicutes mja methanocaldococcus jannaschii archaea euryarchaea mka methanopyrus kandleri archaea euryarchaea mth methanothermobacter thermautotrophicus archaea euryarchaea mtu mycobacterium tuberculosis bacteria actinobacteria neq nanoarchaeum equitans archaea nonarchaea mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset neu nitrosomonas europaea bacteria -proteobacteria nwi nitrobacter winogradskyi bacteria -proteobacteria pab pyrococcus abyssi archaea euryarchaea pac propionibacterium acnes bacteria actinobacteria pae pseudomonas aeruginosa bacteria -proteobacteria pai pyrobaculum aerophilum archaea crenarchaea pfa plasmodium falciparum eukarya alveolata plt prevotella intermedia bacteria bacteroidete ppr photobacterium profundum bacteria -proteobacteria rme cupriavidus metallidurans bacteria -proteobacteria rpa rhodopseudomonas palustris bacteria -proteobacteria rpr rickettsia prowazekii bacteria -proteobacteria rru rhodospirillum rubrum bacteria -proteobacteria sce saccharomyces cerevisiae eukarya fungi sso sulfolobus solfataricus archaea crenarchaea syc synechococcus elongatus bacteria cyanobacteria syn synechocystis sp. bacteria cyanobacteria tac thermoplasma acidophilum archaea euryarchaea tbd thiobacillus denitrificans bacteria -proteobacteria tcr trypanosoma cruzi eukarya euglenozoa tde treponema denticola bacteria spirochetae tel thermosynechococcus elongatus bacteria cyanobacteria tth thermus thermophilus bacteria deinococcus zmo zymomonas mobilis bacteria -proteobacteria table 2: enzymes, characters selected in the study group data code enzyme name ec gene name b/ 1 5-aminolevulinate synthase 2.3.1.37 alas, hema c/ 2 glutamyl-trna synthetase 6.1.1.17 gltx, others d/ 3 glutamyl-trna reductase 1.2.1.70 hema e/ 4 glutamate-1-semialdehyde 2,1aminomutase 5.4.3.8 heml mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f/ 5 porphobilinogen synthase 4.2.1.24 hemb g/ 6 hydroxymethylbilane synthase 2.5.1.61 hemc h/ 7 uroporphyrinogen-iii synthase 4.2.1.75 hemd i/ 8 uroporphyrinogen decarboxylase 4.1.1.37 heme j/ 9 uroporphyrinogen methyltransferase 2.1.1.107 hemx, cysg, coba k/ 10 precorrin-2 dehydrogenase 1.3.1.76 cysg l/ 11 sirohydrochlorin ferrochelatase 4.99.1.4 cysg m/ 12 sirohydrochlorin cobaltochelatase 4.99.1.3 cbix, cbik n/ 13 cobalt-factor ii c20-methyltransferase 2.1.1.151 cbil, cbil, cbif o/ 14 precorrin-3 methyltransferase 2.1.1.131 cbih, cbil,cobj p/ 15 precorrin-3 methylase 2.1.1.133 cbif, cobm q/ 16 precorrin-6a reductase 1.3.1.54 cobl, cobk s/ 17 precorrin-6 methyltransferase 2.1.1.132 cbie, cbit, cobl t/ 18 precorrin isomerase 5.4.1.2 cobh, cbic u/ 19 cob(ii)yrinic acid a,c-diamide reductase 1.16.8.1 v/ 20 cob(i)yrinic acid a,c-diamide 2.5.1.17 cobo, coba, btur adenosyltransferase w/ 21 adenosylcobyric acid synthase (glutaminehydrolysing 6.3.5.10 cbip, cobq x/ 22 adenosylcobinamide-phosphate synthase 6.3.1.10 cobd, cbib y/ 23 adenosylcobinamide kinase 2.7.1.156 cobu, cobp z/ 24 adenosylcobinamide-gdp ribazoletransferase 2.7.8.26 cobs aa/ 25 alpha-ribazole phosphatase 3.1.3.73 cobc ab/ 26 cob(i)yrinic acid a,c-diamide adenosyltransferase 2.5.1.17 ac/ 27 aquacobalamin reductase 1.16.1.3 ad/ 28 precorrin-2 c20-methyltransferase 2.1.1.130 cbil, cobi mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ae/ 29 precorrin-3b synthase 1.14.13.83 cobg af/ 30 precorrin-6a synthase (deacetylating) 2.1.1.152 cobf ag/ 31 coproporphyrinogen oxidase 1.3.3.3 hemf ah/ 32 coproporphyrinogen dehydrogenase 1.3.99.22 hemn aj/ 33 protoporphyrinogen oxidase 1.3.3.4 hemg ak/ 34 protoporphyrin ix magnesiumchelatase 6.6.1.1 chld, bchl al/ 35 magnesium protoporphyrin ix methyltransferase 2.1.1.11 chl, bchl am/ 36 mg-protoporphyrin ix monomethyl ester (oxidative) cyclase 1.14.13.81 acs, pni an/ 37 protochlorophyllide reductase 1.3.1.33 ao / 38 chlorophyllase 3.1.1.14 ap / 39 chlorophyll synthase 2.5.1.62 aq / 40 ferrochelatase 4.99.1.1 hemh ar/ 41 ferroxidase; ceruloplasmin 1.16.3.1 as / 42 cytochrome c heme-lyase 4.4.1.17 at / 43 heme oxygenase 1.14.99.3 au / 44 phytochromobilin:ferredoxin oxidoreductase 1.3.7.4 av / 45 phycocyanobilin:ferredoxin oxidoreductase 1.3.7.5 aw / 46 15,16-dihydrobiliverdin:ferredoxin oxidoreductase 1.3.7.2 ax / 47 phycoerythrobilin:ferredoxin oxidoreductase 1.3.7.3 ay / 48 biliverdin reductase 1.3.1.24 az / 49 bilirubin oxidase 1.3.3.5 ba / 50 bilirubin udp-glucuronosyltransferase 2.4.1.17 bb / 51 beta-glucuronidase 3.2.1.31 the absence or presences of an enzyme in the metabolism of organisms that constitute the study group are discrete characters that are encoded in a binary system, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 2; march april 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 0 or 1. this coding means that an enzyme can be in two states: 0-absent or 1-present. data have been collected from kegg: kyoto encyclopedia of genes and genomes (1995-2015 kanehisa laboratories) the set of taxa and characters are reflected in a "matrix data" showing taxa in rows and states of a character in columns (tale 3). this matrix is the basis for further analysis. table 3: data matrix showing the states of the characters (0-absent enzyme, 1present enzyme) table 3. cont. mailto:topacademicjournals@gmail.com pérez-urria, elena & avalos, adolfo 10 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a data matrix as the above in which the reflected characters are metabolic enzymes in two states, present (1) or absent (0), serves for the cladistic analysis of enzymes and accordingly the metabolism of porphyrins and chlorophylls in organisms of the study group. the cladistic analysis was performed with the mix program in phylip (felsestein, 2001) (http://evolution.genetics.washington.edu/phylip.html) which estimates phylogenies by wagner parsimony method for discrete character data with two states (0 and 1) (also available an online version of the program pérez-urria, elena & avalos, adolfo 11 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset http://mobyle.pasteur.fr/cgi-bin/portal.py#jobs::overview). cladograms and trees are drawn with phy.fi application (fredslund, 2006). the result of this analysis is reflected by a cladogram representing an evolutionary hypothesis discussed below. 4. one hypothesis about the evolution of porphyrins and chlorophylls the cladistic analysis following wagner parsimony method for discrete characters in two states provides 100 equally parsimonious trees (l = 233). figure 2 shows the majority rule consensus tree and figure 3 shows the strict consensus tree of the 100 most parsimonious and equally parsimonious trees. in the majority rule consensus tree two large groups or clades are observed: one formed by bacteria and archaea and another group of bacteria and eukaryota (fig. 2). this result is confirmed by the strict consensus tree (fig. 3). the ancestral metabolism corresponds to nanoarchaeum equitans (neq) leaving immediately after the ancestor (anc, the hypothetical ancestor with all characters set to 0, plesiomorphic, ie, absent). all enzymes considered undergo at least one change of state. those experiencing a single change (bold in the table 2) are apomorphic characters which define well metabolism (red arrows in fig. 1). all other enzymes experience more than one change, they are homoplasy, indicate convergent evolution, the adaptive nature of metabolism and its components. in the clade metabolism [bacteria + archaea] the group of cyanobacteria (tel, gvi, syn, ana and syc) is well defined by the enzyme phycocyanobilin:ferredoxin oxidoreductase (ec 1.3.7.5) which experience a unique change and is a sinapomorphic character for the cyanobacteria clade. within this group of cyanobacteria, gloeobacter violaceus (gvi) is defined by two apomorphic characters: enzymes 15,16dihydrobiliverdin:ferredoxin oxidoreductase (ec 1.3.7.2) and phycoerythrobilin:ferredoxin oxidoreductase (ec 1.3.7.3). on the basis of this group of cyanobacteria, in a previous node, is the metabolism of chloroflexus aurantiacus (cau) defined by an autoapomorphy, the bilirubin oxidase enzyme (ec 1.3.3.5). the clade metabolism [bacteria + eukarya] includes among eukaryotes arabidopsis thaliana (ath), plant whose metabolism is well defined by two apomorphies, enzymes chlorophyllase (ec 3.1.1.14) and phytochromobilin: ferredoxin oxidoreductase (ec 1.3.7.4). all other groups or clades are not based on apomorphic characters, no homologies to well define species metabolism. therefore they are analogies and a case of convergent or parallel evolution. the similarity is due to homology and analogy. but nevertheless analogies or homoplasies not serve to discover phylogenetic relationships. therefore they can not be established assumptions about relationships between sister groups based on the metabolism of porphyrins and chlorophylls. resulting cladograms both majority consensus as strict consensus (figs. 2 and 3) reflects relationships derived from adaptive changes that lead to the expression, or not, of a gene and possible synthesis or catalytic activity of an enzyme as well as the acquisition or loss metabolic capabilities as an adaptive response to the environment. moreover, lateral gene transfer is a key process in the early stages of cellular evolution that draws a complex network of relationships that mask and / or replace the vertical transfer and evolution model based on ancestry with modification. on the other hand, much of the diversity found in algae is due to secondary and tertiary endosymbiotic events (keeling, 2010). pérez-urria, elena & avalos, adolfo 12 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset pérez-urria, elena & avalos, adolfo 13 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the metabolism compared in the study group makes clear enzymes that change once. some of these elements as apomorphic homologies could be phylogenetic markers. this is the case of phycocyanobilin:ferredoxin oxidoreductase (ec 1.3.7.5) for cyanobacteria and chlorophyllase (ec 3.1.1.14) for plants. green algae and its progeny lost the cyanobacterial phycobilisome lightharvesting system, whereas red algae (cme, cyanidioschyzon merolae) (on the cladogram with arabidopsis thaliana) and glaucophytes retained it. the chloroplasts in algae and plants are derived from cyanobacteria and endosymbiosis gave rise to photosynthetic eukaryotes (margulis, 1992). the evolution of photosynthesis is a complex process involving different sources and routes of its many components, so that its history can not be described as a simple, linear process. however, it seems certain that the emergence of mg-tetrapyrrole and apoproteins of the reaction centers are key events that led to the development of the photosynthetic process. the flow of electrons acceptor—is channeled by protein complexes that always contain metallo-organic cofactors. membrane-bound complexes couple the transfer of electrons across the membrane to the generation of an ion gradient and transmembrane electrical potential. this chemiosmotic mechanism was likely present in the last common ancestor and has been carried forward to the three presently persisting domains of life, bacteria, archaea, and eukarya (lane et al., 2010). the granick (granick, 1965) and retrograde (horowitz, 1945) hypotheses on the establishment of metabolic pathways are complementary. granick established as hypotheses that the intermediate compounds of the modern biosynthetic pathways were the final products of early pathways and thus the evolution of the pathway can be traced from the beginning to the end. however this contrasts with the retrograde hypothesis which posits that present biosynthetic pathways are set up in the reverse order to their evolutionary history and occurred through gene duplications. but the granick and retrograde hypotheses are not mutually exclusive because the retrograde hypothesis is a consequence of the depletion of base molecules present in the primordial soup, molecules that follow the granick hypothesis may be more derived. there are still many aspects of the evolution of photosynthesis unresolved due in part to the existence of highly diversified components (fig.4). one way to learn more about this issue is to address the systematic, descriptive and comparative study of genes and gene products of photosynthesis in the diversity of phototrophic organisms. for this purpose contributes undoubtedly the availability of numerous molecular data and the use of phylogenetic analysis tools. for example and based on the results of this study, comparative analysis of enzymes glutamyltrna synthetase (ec 6.1.1.17), porphobilinogen synthase (ec 4.2.1.24) and protoporphyrinogen oxidase (ec 1.3.3.4) arises with all this new knowledge will continue to emerge thus reconstruct the evolutionary history of photosynthesis. pérez-urria, elena & avalos, adolfo 14 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: some molecules of metabolism of porphyrins and chlorophylls 5. references cavalier-smith, t. (1992). bacteria and eucaryotes. nature, 356: 570. cunchillos, c. y lecointre, g. (2002). early steps of metabolism evolution inferred by cladistic analysis of amino acid catabolic pathways. c.r. biologies, 325: 119129. cunchillos, c. y lecointre, g. (2003). evolution of amino acid metabolism inferred through cladistic analysis. the journal of biological chemistry, 278 (48), nov.: 47960-47970. cunchillos, c. y lecointre, g. (2005). integrating the universal metabolism into a phylogenetic analysis. mol. biol. evol., 22 (1): 1-11. des marais, d.j. (2000). when did photosynthesis emerge on earth? science, 289: 1703-1705. enzyme nomenclature (1973). recommendations (1972) of the international union of pure and applied chemistry and the international union of biochemistry. elsevier scientific publishing company, amsterdam. felsenstein, j. (2001). phylip (phylogeny inference package). version 3.6a3. department of genetics. university of washington, seattle. fredslund, j. (2006). phy·fi: fast and easy online creation and manipulation of phylogeny color figures. bmc bioinformatics 7:315. pérez-urria, elena & avalos, adolfo 15 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset granick, s. 1965. evolution of heme and chlorophyll. in evolving genes and proteins, ed. v bryson, hj vogel, pp. 67–88. new york: academic. horowitz, n.j. 1945. on the evolution of biochemical synthesis. proc. natl. acad. sci. usa 31:153–57 kegg: kyoto encyclopedia of genes and genomes 1995-2015 kanehisa laboratories. available on http://www.genome.jp/kegg/ keeling, p.j. 2010. the endosymbiotic origin, diversification and fate of plastids. philos. trans. r. soc. lond. b 365:729–48. lane, n, allen, j.f, martin, w. 2010. how did luca make a living? chemiosmosis in the origin of life. bioessays 32:271–80. margulis, l. 1992. symbiosis in cell evolution. san francisco: freeman. nisbert, e.g. y sleep, n.h. (2001). the habitat and nature of early life. nature, 409: 1083-1091. olson, j.m. (1999). early evolution of chlorophyll-based photosystems. chemtracts, 12: 468-482. olson, j.m. (2001). evolution of photosynthesis (1970), re-examined thirty years later. photosynth. res., 68:95112. schidiowski, m. (1988). a 3.800-million-year isotopic record of life from carbon in sedimentary rocks. nature, 333: 313-318. shopf j.w. (1993). microfossils of the early archean apex chert: new evidence ofthe antiquity of life. science, 260: 640-646. schopf, j.w. y packer, b.m. (1987). early archean (3.3-billion to 3.5-billion year old) microfossils from warrawoona group. australia. science, 237: 70-73. woese, c.r. (1987). bacterial evolution. microbiol. rev., 51: 221-271. 060909-zpk230019 academic journal of engineering and technology science .docx academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a greener future: energy-saving control's role in mechanical and electronic engineering advancements zhu, yi-qiang college of mechanical and transportation, southwest forestry university, kunming, 650000, yunnan, china abstract: energy-saving control systems play a pivotal role in the realm of mechanical and electronic engineering, facilitating the efficient management of mechanical and electrical equipment while curbing energy wastage. this article delves into the energy-saving control of asynchronous motors for vehicles, with the primary objective of reducing energy consumption and enhancing motor efficiency. the study also aims to extend the electric vehicle's operational range, contributing significantly to the advancement of wang mechanical and electronic engineering. by integrating energy-saving control systems into mechanical and electrical engineering, this research endeavors to amplify energy conservation without compromising the equipment's regular functioning, optimizing energy utilization and yielding superior performance. this not only augments the machinery and electronics sector but also fosters sustainable development across economic, energy, and environmental domains. keywords: energy-saving control systems, asynchronous motors, electric vehicles, mechanical and electrical engineering, sustainable development 1. introduction the use of energy-saving control systems in mechanical and electronic engineering can achieve efficient energysaving control of mechanical and electrical equipment, while ensuring the normal operation of mechanical equipment and minimizing energy losses as much as possible. this is of great significance for the energy-saving development of wang mechanical and electronic engineering. in view of this, this article takes the energy-saving controller of asynchronous motors for vehicles as the research object, with the goal of reducing motor energy consumption and improving motor efficiency, and focuses on extending the range of electric vehicles. this study can provide reference for the application and development of mechanical, electrical, and electrical fields. applying energy-saving control systems to mechanical and electrical engineering can significantly improve the energy-saving effect of the machine while ensuring its normal operation, maximizing the energy utilization rate of the machine, and thus achieving the best working results. this is not only conducive to the development of machinery and electronics, but also to the sustainable development of today's economy, energy, and environment. energy saving control technology is currently one of the hot topics in research, among which huang huacheng explored iot control technology based on iot campus energy-saving and consumption reducing street light systems [1]. ashryatov, a. a., v. g. kulikov considered the advantages of electronic starting devices in street light control systems in order to create energy-saving control systems. they analyzed the current status of street light lighting methods, identified their shortcomings and solutions, and developed energy-saving control methods for street light lighting devices [2]. chang jau-yang has designed a multi hop based energy-saving control scheme mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to handle the sleep process of sensor devices. based on the multi hop routing structure, self-adaptive decisions are made to select the type of power saving level, which brings reasonable energy consumption and appropriate packet delay time to sensor devices [3]. ding renkai ruochen wang has designed an energy-saving control strategy and its corresponding implementation structure to reconcile the contradiction between dynamic performance and energy consumption [4]. however, due to insufficient data sources, the above research is only in the theoretical stage and lacks practical significance. 2. design of energy-saving controller for asynchronous motors this article focuses on the hardware design of the energy-saving controller for asynchronous motors used in electric vehicles. based on the overall design scheme of the energy-saving controller hardware, the various components of the energy-saving controller hardware system were selected and analyzed in detail. using the relevant design software aluminum designer 16, the circuit schematic diagram and circuit board were designed and drawn [5-6]. 2.1. hardware design of energy-saving controller the energy-saving controller for automotive asynchronous motors designed in this article mainly includes dsp control circuit, ipm main circuit, signal detection circuit, etc. [7]. this article is based on the design of hardware circuits that achieve different functions, and organizes and arranges them, including the following contents: circuit schematic diagram and overall layout plan. the overall hardware structure of the energy-saving controller is shown in figure 1. figure 1. overall structure of the energy-saving controller hardware system dc power supply voltage conversion circuit filter circuit signal processing circuit voltage sensor mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.2. control circuit design of digital signal processing technology the energy-saving control technology introduced in this article is mainly an energy-saving control circuit designed based on the dsp chip tm320f28335. the design of the dsp control circuit is the most important part of the entire hardware system design [8-9]. in this section, the basic features of the f28335 main control chip are first introduced. then, based on the current mature technological achievements, the corresponding design of the dsp control circuit was carried out, and a dsp control circuit that meets the requirements of the work in this article was ultimately developed. the digital signal processing technology (dsp) utilizes an event triggering module in enhanced pulse width modulation (epwm) to generate the interrupt signal or transform signal; by using a driver isolation circuit, a pulse width modulation (pwm) signal is transmitted to an intelligent power module (ipm) for switching action; after performing voltage transformation, filtering, and limiting operations, the sampled signal can be transmitted to the dsp's transformation module if it meets the conditions for input analog signals. the fault protection signal of ipm is output to the dsp main control chip, which effectively protects the inverter circuit [10]. 2.3. software system design of energy-saving controller this article introduces a new type of energy-saving controller for asynchronous motors and provides a detailed analysis of it. on the hardware platform of the energy-saving controller designed in this article, the software system design of the asynchronous motor energy-saving controller was completed using dedicated integrated development software of dsp chips, and subsequent debugging and improvement work was carried out [11-12]. (1) system main program design in this article, a detailed analysis and research have been conducted on the control technology of induction motors. in practical applications, due to its own characteristics and characteristics, a detailed analysis has been conducted and corresponding solutions have been proposed. therefore, in order to ensure that the energy-saving controller achieves the expected functions, it is necessary to accurately digitize various input signals, efficiently process signals, and output control signals in real-time. there are a large number of self-protection lines in energy-saving control systems. how to quickly and stably process fault signals at the software level is also the key to ensuring the safe and stable operation of energy-saving control systems. in this scheme, programming is carried out in a modular manner, ensuring that the overall code structure of the system is clear, concise, and easy to understand, while also facilitating later maintenance and updates [13]. the software system design scheme in this article consists of two parts: the main program and the interrupt submodule. the main program completes the input instructions of the upper computer after initialization, and the interrupt submodule includes modules such as ad conversion, coordinate transformation, and energy-saving control. the a/d acquisition circuit collects the signal output by the hall sensor and converts it into a digital quantity; the qep testing module mainly includes: calculation of the position and speed of the rotor flux linkage; the coordinate conversion module completes karat conversion, parker conversion, and parker inverse conversion; the energy-saving control module adjusts the mt axis current based on theory and analysis, and the motor load condition. the flowchart of the main program is shown in figure 2. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2. main program flowchart (2) energy saving control module in the software design of energy-saving controllers, the energy-saving control module is the most important and crucial part [14-15]. due to the difficulty in directly measuring the load of an induction motor under normal operating conditions, this article uses stator current as an intermediary to indirectly obtain the magnitude of the induction motor load. based on the above theoretical analysis, it can be concluded that when the motor is operated under different load conditions, there would be an optimal voltage value corresponding to it. the energy-saving control module can control the supply voltage value through the measured stator current, thereby reasonably reducing the magnetic flux level, reducing motor losses, and improving the working efficiency of asynchronous motors. when the load changes, the system comprehensively judges whether energy-saving regulation is necessary under the current load state of the asynchronous motor based on the current i, current current, and threshold detected in the previous round [16-17]. to avoid oscillation of the optimization search operation around the optimal value during the energy-saving regulation process, which may cause unstable power supply voltage and cause excessive vibration and noise. so, when the amplitude of current change exceeds the pre-set threshold, the induction motor would enter the energy-saving regulation mode. the flowchart of the energy-saving control module is shown in figure 3: start system initialization gpio initialization peripheral interrupt initialization on-chip peripheral initialization peripheral interrupt enable asynchronous motor energy saving controller operating normally stop n y mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3. energy saving control subroutine flowchart 2.4. implementation of frequency converters and their energy-saving principles in this energy-saving control system, the main function of the frequency converter is to regulate the induced draft fan, water supply system, and blower. according to the relevant principles of electrical engineering, the attack operating speed of ac asynchronous points can be calculated according to the following formula: n = 60 (1f −s)/ p (1) in the formula, the stator power supply frequency is represented by f; p is the polar logarithm; s is the slip rate. from this formula, it can be seen that if the frequency of the stator power supply is changed at a constant speed, the synchronous operating speed of the motor would also undergo a stable change, thus obtaining a better regulated air volume. from a theoretical perspective, since the air flow rate is directly proportional to the first order of the rotational speed, and the air pressure is directly proportional to the square of the rotational speed, the shaft work is directly proportional to the third order of the rotational speed. from this point of view, compared to adjusting dampers, adjusting the operating rate would achieve a more significant energy-saving effect for the energy saving control subroutine entry judgment mode read the current value of ad conversion is it greater than the threshold finish n y mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset boiler. in the energy-saving control system studied in this article, the actuator is a frequency converter. by adjusting the operating speed, the air blowing volume and water supply volume can be reasonably changed. the formula for calculating power savings is as follows: ∆ =n h h q( 1 − 3)* 2 (2) according to the theory of fluid mechanics: q p= (3) h the air volume q is proportional to the first power of the speed n, the pressure h is proportional to the second power of the speed n, the shaft power p is proportional to the third power of the speed n, and the motor speed n is proportional to the power frequency. 3. experiment and energy-saving controllers in mechanical and electronic engineering on this basis, a 4 kw three-phase induction motor is used as the research object, and an energy-saving control device is used, with an ammeter as the motor load [18-19]. in this experiment, the conventional technical parameters of the motor drive system were tested, and a comparative test of control variables was conducted. except for the connection of energy-saving controllers, other operating modes and configurations were the same. experiments were conducted on induction motors in the above two states, and the test results were analyzed. on this basis, through a series of comparative experiments, the problem can be quickly identified and more conclusions can be drawn. the specific meanings of each working condition in the horizontal axis are shown in table 1. table 1. motor load conditions corresponding to each working condition case number load rate 1 0 2 5 3 15 4 25 5 30 6 40 7 50 8 55 9 65 10 70 here, the experimental process of this article includes the following aspects: firstly, record the corresponding voltage and current values in the three phases. the second is to connect the power plug properly. the console of the electromagnetic eddy current dynamometer sets the torque to 0, which is equal to no load. at the same time, the output electrical energy can also be measured on three phases. thirdly, connect an electromagnetic force mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset meter and gradually increase the torque of the electromagnetic force meter, which is equivalent to gradually increasing the load of the induction motor. every once in a while, the electrical energy display at its input end, as well as the voltage and current corresponding to the three phases, would be measured. fourthly, repeat the above steps three times to ensure that the interval time and torque value are the same. therefore, the comparison of stator current of induction motors in vehicles with and without energy-saving controllers is shown in figure 4 [20]. as shown in figure 5, the lower the load rate, the smaller the stator current, and the better the energy-saving effect. this is due to the increase in load, as the optimal magnetic flux tends towards the rated value, which also verifies the effectiveness of the minimum stator current control technology. the statistical diagram of the changes in power factor is shown in figure 5 [21]. figure 4. comparison of stator current 0 0.2 0.4 0.6 0.8 1 1.2 1 2 3 4 5 6 7 8 9 10 stator current no energy saving energy saving mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5. improvement of power factor as shown in figure 5, under the condition of energy conservation, the improvement in condition 2 is the largest, with a value of 67%. under the condition of not using any energy, the efficiency improvement under condition 6 is the highest, reaching 65%. the smaller the load ratio, the more significant the effect on improving power factor. this can not only save the active power consumption of the induction motor, but also effectively reduce the power consumption of the motor and improve the transmission performance of the motor. during the experiment, every time the state is switched and the load of the asynchronous motor is changed, the energy-saving controller of the automotive asynchronous motor maintains good dynamic response characteristics. throughout the entire experiment, there is no motor stall, and its various indicators are stable and reliable, basically meeting the needs of extending the range of electric vehicles. therefore, it is an energy-saving supporting equipment for asynchronous motors used in electric vehicles with good practicality. so, after constructing an energy-saving control experimental platform for automotive asynchronous motors, this article tested the experimental device, and the feedback of the test results showed that the basic functions of this experimental platform were complete and reliable, ultimately achieving experimental research on energy-saving controllers for automotive asynchronous motors. by testing some of the main performance parameters of the energy-saving control system, various performances of the energy-saving control system were tested, and the performance of the energy-saving control system was also tested. the two main performance parameters and 0 10 20 30 40 50 60 70 80 1 2 3 4 5 6 7 8 9 10 working condition have energy saving no energy saving mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset dynamic and static operating characteristics of the energy-saving controller were experimentally studied through comparative experiments. 4. conclusions the electrical equipment has undergone energy-saving transformation using electrical equipment and electrical equipment. therefore, in future research work, it is also necessary to increase the exploration and exploration of energy-saving control technologies, continuously improve and enhance existing energy-saving control technologies, and promote the development of energy-saving control in mechanical and electronic engineering from multiple perspectives. therefore, combining energy conservation technology with mechanical design would completely eliminate various difficulties that currently hinder the development of energy conservation technology, and play a huge promoting role in the development of mechanical design and manufacturing. in order to solve the problem of vector control and achieve high-speed dynamic response, some power losses may occur when the motor is unloaded or lightly loaded. therefore, this paper proposes an energy-saving control technology for automotive asynchronous motors based on the minimum stator current method, which exchanges the optimal energy with a certain response speed under conditions of different load rates and no high demand for dynamic response. references huang huacheng. "analysis of energy saving and consumption reduction technology in iot control systemcampus energy saving and consumption reduction street light system as an example." turkish journal of computer and mathematics education (turcomat) 12.11 (2021): 3950-3957. ashryatov, a. a., v. g. kulikov, and a. v. panteleyev. "energy saving control system development for external lighting." indonesian journal of electrical engineering and computer science 17.3 (2020): 1601-1606. chang jun-yang, jing jin-song, and wu jun-yi. "multi-hop based energy-saving control scheme for internet-ofthings systems." journal of the chinese institute of engineers 45.6 (2022): 543-555. [4] ding renkai, wang ruochen, and meng xiangpeng. "energy-saving control strategy design and structure realization for electromagnetic active suspension." proceedings of the institution of mechanical engineers, part c: journal of mechanical engineering science 233.9 (2019): 3060-3075. [5] zhang biying, jin shangtai, and hou zhongsheng. "energy saving control of bionic robotic fish based on model-free adaptive control." ifac-papersonline 53.2 (2020): 3934-3939. xing yazhou. "optimisation of energy-saving control parameters of urban underground sewage treatment pumps based on fuzzy parameter adaption." international journal of global energy issues 42.5-6 (2020): 339354. xiuying yan, pengfei yu, and. dengjia wang. "flexible energy-saving control strategy of a solar-ashp integrated heating system based on time-sharing heat demand." distributed energy resources 8.1 (2023): 1-10. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset zheng, mali. "research on energy-saving control and optimisation of air conditioning system based on genetic algorithm." international journal of global energy issues 43.1 (2021): 38-54. [9] jin zheliang, and martinez davis. "energy-saving control method of electric heating film temperature for urban zero energy consumption building heating." international journal of global energy issues 42.5-6 (2020): 323-338. fung rongfong, and wu tsung-liang. "dynamic formulation, identification and energy-saving control for an lcd glass-handling robot system." international journal of dynamics and control 8.1 (2020): 1-20. li dongmei. "analysis on the monitoring system of energy conservation and comfort in office buildings based on internet of things." international journal of low-carbon technologies 15.3 (2020): 351-355. wen xiaolong. "research on an optimisation control method of large-scale buildings energy saving based on particle swarm optimisation." international journal of global energy issues 44.2-3 (2022): 166-181. watanabe shoichiro. "verification of optimized energy-saving train scheduling utilizing automatic train operation system." ieej journal of industry applications 9.2 (2020): 193-200. ding damin. "energy-saving optimization on active disturbance rejection decoupling multivariable control." nuclear engineering and technology 55.3 (2023): 850-860. chen yu. "an energy-saving fuzzy control fan array with bluetooth received signal strength indicator sensing." sensors and materials 34.9 (2022): 3449-3459. fei xiaotao, yunwu han, and shaw voon wong. "an overview of and prospects for research on energy savings in wheel loaders." automotive experiences 6.1 (2023): 133-148. sun xiaoye. "research and evaluation of energy-saving reconstruction of intelligent community heating system based on the internet of things." international journal of heat and technology 39.3 (2021): 701-710. yang guoqiang. "adoption of energy-saving materials in the design of hotel intelligent system under low carbon environment." integrated ferroelectrics 215.1 (2021): 256-266. wang j. f. "energy-saving operation of multistage stochastic manufacturing systems based on fuzzy logic." international journal of simulation modelling 18.1 (2019): 138-149. tingting wang. design and implementation of environmental protection publicity based on green energy effect. nature environmental protection (2022), vol. 3, issue 3: 54-61. ken lawrence. resource balance optimization method of mechanical engineering project considering multiobjective optimization. kinetic mechanical engineering (2023), vol. 4, issue 1: 1-10. mailto:topacademicjournals@gmail.com 060907-pk132《academic journal of engineering and technology science》 .docx academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a blueprint for iot-powered laboratory security systems sun, yi-fang college of information engineering, liaodong university, dandong, china abstract: the internet of things (iot) has emerged as a transformative paradigm, enabling the seamless exchange of information between interconnected objects through agreed-upon protocols. this interconnectedness extends the concept of networking from the digital realm to the physical world, facilitating intelligent identification, positioning, tracking, and supervision functions. iot is inherently intertwined with the internet and sensor networks, particularly wireless sensor networks (wsns). wsns consist of numerous sensors strategically placed to detect and transmit data wirelessly, creating self-organizing intelligent network information systems. as iot technology advances and matures, it presents a promising opportunity to enhance laboratory safety management through the development of iot-based laboratory security systems. keywords: internet of things (iot), sensor networks, laboratory safety management, information exchange, intelligent network system 1. introduction the internet of things refers to the information sensing equipment, according to the agreed protocol, any object connected to the network, the object through the information communication media information exchange and communication, in order to achieve intelligent identification, positioning, tracking and supervision and other functions. the internet of things extends the network concept of communication and information exchange in the actual information world to the physical world, which includes the activities of property and things or property and people. the internet of things is closely connected with the internet and sensor network [1]. sensor network is short for wireless sensor network. the sensor network is a large number of sensors randomly designed by the nodes of the data processing unit and the communication unit as well as the detection area. it uses the wireless network to implement information transmission, and the information interaction between things and things and between things and people is realized in the form of a self-organizing intelligent network information system [2]. the internet of things technology has been developing rapidly and gradually becoming mature, which provides a new technical guarantee for laboratory safety management. develop a laboratory security system based on the internet of things to provide information and intelligent management means for laboratory security. 2. zigbee technology zigbee is one of the most important wireless protocols in wireless communication and has been widely used in various internet of things communication fields. zigbee is a short-range, low-complexity, low-power, low-cost bidirectional wireless communication technology, mainly used in the data transmission between various devices with close distance, low power consumption and low transmission rate. zigbee is based on the ieee802.15.4 standard. the ieee802.15.4 standard only defines the physical layer protocol and the mac layer protocol, and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the zigbee alliance standardizes its network protocol layer and api on this basis, and also develops a security layer. after the improvement of ieee802.15.4 by zigbee alliance, the zigbee protocol stack is finally formed. the zigbee protocol framework structure is shown in figure 1. in the zigbee protocol framework structure, the physical layer is the most basic part of the protocol stack, including the basic functions of physical signal reception and transmission processing, signal measurement, and transceiver state adjustment and parameter setting. the media access layer is responsible for how wireless channels are used, establishing and maintaining pans, processing and maintaining guaranteed gts, and coordinating the proper use of communication resources across multiple devices. network layer to achieve network establishment, routing and network address allocation, the internal is divided into network layer data entity and network layer management entity, including coordinator, router and terminal node three types of devices. the application layer includes application support sub-layer aps, application framework af, and zigbee device object zdo, which together provide a unified interface for application developers [3,4]. figure 1: zigbee protocol framework structure there are three device roles in zigbee networks, including coordinator, router and terminal. among them, the zigbee coordinator is the information collection point and core node of the entire network, responsible for the construction, maintenance and management of the network. the coordinator is usually zigbee's gateway, responsible for the conversion to other protocols such as wi-fi, while having all the functions of a router. the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset router can send and receive data, and is responsible for searching and maintaining the path of data, so that the router or terminal device can join the network, usually as a coordinator and the terminal device relay node used. the terminal device can send and receive data, but cannot route data. the terminal device can be mounted only to the coordinator or router node. it is usually a low-power device, such as mounting various sensors, relays and switches. zigbee technology has the following main characteristics: first, low power consumption, zigbee network node devices have a short working cycle, low power to send and receive information, and adopt sleep mode, low power consumption performance is significant. second, short delay, communication delay and the delay of activation from sleep state are very short, the device search delay is 30ms, the sleep activation delay is 15ms, and the active device channel access delay is 15ms. third, low cost, zigbee protocol stack design is simple, the agreement is free of patent fees, coupled with the use of the frequency band does not need to pay, so the cost of zigbee products is low. fourth, the network capacity is large, a star structure zigbee network can accommodate up to 255 devices, and the network composition is flexible. the mesh structure of zigbee network can theoretically support 65535 nodes. fifth, high reliability, zigbee adopts collision avoidance strategy to avoid the competition and conflict of sending data. the mac layer adopts the fully confirmed data transmission mode. each sent packet must wait for the confirmation information of the receiver. if there is a problem in the transmission process, it can be resent. sixth, high security, zigbee provides data packet integrity check function based on cyclic redundancy check (crc), supports authentication and authentication, adopts aes-128 encryption algorithm, each application can flexibly determine its security attributes. 3. rfid technology rfid is located in the perception layer of the internet of things architecture, which is the lowest level of the internet of things and one of the mediums connecting with "everything". rfid consists of a transponder, a reader and an application software system. the transponder consists of an antenna, coupling components and chips, usually called the tag transponder, generally divided into passive, active and semi-active, each electronic tag has a unique electronic code to determine the target object. the reader consists of an antenna, a coupling element, a chip, and a device capable of reading and writing the tag information, and can be designed as a handheld rfid reader or a stationary reader. application software system is application layer software, which mainly collects and further processes data for people to use [5]. the composition of rfid system is shown in figure 2. d ecoder physical storage encoder instruction / response unit logical storage response coupling element control unit electronic tag c/r agreement logical storage table i nstruct r esponse reader writer transceiver module additional interfaces data processing unit spatial media ┉ usb, rs232 el al. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2: rfid system composition the basic working principle of rfid system: the reader sends a radio frequency signal of a specific frequency through the transmitting antenna. when the electronic tag enters the effective working area, the induced current is generated, and the energy is activated, so that the electronic tag transmits its encoded information through the built-in antenna. the receiving antenna of the reader receives the modulated signal sent from the tag, and transmits it to the signal processing module of the reader through the modulator of the antenna. after demodulation and decoding, the effective information is transmitted to the background host system for related processing. the host system recognizes the identity of the tag according to the logical operation, makes corresponding processing and control for different settings, and finally sends a signal to control the reader to complete different read and write operations. the essence of the internet of things is perception, and the perception between objects is realized through radio frequency identification technology. therefore, the application of radio frequency identification technology rfid is the core of the internet of things [6]. the advantages of rfid technology are obvious, the information in the electronic tag can be read and written repeatedly, the identification is strong, the reading speed is fast, the utilization efficiency is greatly improved, the information format in the electronic tag is unique, the labeled object has become unique, and the "thing" in the internet of things has become unique. because of this, rfid technology is widely used in many areas of the internet of things such as item tracking, real-time monitoring, vehicle management, smart furniture, environmental monitoring and laboratory security to achieve the identification, control, interconnection and supervision of objects. 4. system architecture the laboratory security system based on the internet of things replaces the manual registration and management of laboratory personnel and equipment information in the past, realizes the information management of laboratory resources, facilitates the sharing of laboratory resources, and enables the management, analysis and statistics of equipment and personnel information. real-time monitoring of water and electricity in the laboratory, and analysis and statistics of the monitored data. each room of the laboratory is monitored and video history playback is provided to prevent various safety accidents. to realize the access control function of the laboratory, only authorized laboratory personnel can enter the laboratory by swiping the card to increase the security of the laboratory. the architecture of laboratory security management system based on internet of things technology is shown in figure 3 [7]. interface layer user interface water flow monitoring electric energy monitoring mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset user layer video monitoring access control dictionary maintenance statistical analysis data layer relational database communicati on link layer zigbee wireless network optical fiber network device sensing layer water flowmeter electric energy meter camera rfid figure 3: system architecture the core functions of the system include four aspects [8]: first, water flow monitoring. the water flow meter is placed in the laboratory, and the distance transmission between the flow meter and the central control room is carried out through the application of optical fiber network, and the optical fiber big data is transmitted to the central server, and then the data is monitored and collected. second, electric energy monitoring. obtain the laboratory electricity situation, respond to and deal with sudden electricity accidents. a professional electrical energy detection box is set up in the laboratory, the current signal is sent by the transformer, and all the signals are uploaded to the power meter. using zigbee wireless transmission method to transmit data, through the optical fiber network and the system connection, the central server accurately read the energy meter data, so as to achieve real-time monitoring effect. third, video surveillance. monitor the dynamic situation of the laboratory, automatically identify the light camera in each room, connect the infrared camera with the client software, collect and transmit video data, and call up the monitoring screen or historical screen in real time. fourth, access control management. check the identity of people entering the laboratory, and only those who have access and meet the requirements can enter the laboratory. the access control system uses rfid radio frequency technology, which can accurately identify the target, and obtain information, and compare it with the information in the database. if the information is consistent, you can gain admission to the laboratory. 5. laboratory safety monitoring and control system laboratory safety hazards mainly include five aspects [9]: first, fire hazards. the occurrence of fire accidents is universal and may occur in almost all laboratories. second, explosive potential. explosive accidents mostly occur mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in laboratories with flammable and explosive materials and pressure vessels. third, potential toxicity. almost all chemicals used in chemical laboratories have certain toxicity, and toxic accidents mostly occur in laboratories with chemical drugs, highly toxic substances and toxic gas emissions. fourth, mechanical and electrical hazards. mechanical and electrical injuries occur mostly in mechanical laboratories with high-speed rotation or impact motion, or electrical laboratories with live work and some laboratories with high temperature. the fifth is the potential theft. the hidden dangers of theft are mostly due to the poor anti-theft performance of the doors and windows of the laboratory, or the responsibility of the relevant personnel is not in place. the laboratory defense system under the condition of internet of things covers all kinds of sensing and detection devices, as shown in figure 4 [10]. figure 4: architecture of laboratory safety monitoring and control system sensors are used to collect laboratory monitoring signals and abnormal state signals of instruments, equipment, fires and hazards to human health during experiments. temperature sensor can feel the temperature and convert to the available output signal, temperature sensor is the core part of the temperature measurement instrument, according to the measurement method can be divided into contact and non-contact two categories. ionic smoke sensor is a kind of advanced technology, stable and reliable sensor, which is widely used in various fire alarm systems, and its performance is far better than that of gas sensitive resistor fire alarm. the human body infrared sensor is used for life anti-theft alarm and visitor notification, etc. the principle is to convert the released charge into voltage output through the amplifier. electrochemical sensors are mainly used to analyze the composition of gases, liquids or solids dissolved in liquids, the measurement of liquid ph, conductivity and redox potential and other parameters. the current and voltage sensor converts the high voltage into a certain value of low voltage for measurement and other uses, which can prevent the current or voltage from being too large to damage the instrument and equipment, and can greatly reduce the risk of electric shock for the experimenter. pressure sensor a device or device that can sense pressure signals and convert pressure signals into usable output electrical signals according to certain rules. 6. conclusions the definition of the internet of things is to use rfid technology, laser scanners, global positioning devices and infrared sensors and many other sensor settings, to connect everything with the network, communication and information exchange into the relevant protocol implementation, to achieve the intelligent goal of identification sound, light, telephone and sms alarm devices smoke sensor laboratory safety monitoring device human infrared sensor feedback control device electrochemical sensor laboratory safety monitoring center laboratory manager terminals such as computers, mobile phones and laptops database /web server current and voltage sensor pressure monitoring sensor temperature and humidity sensor internet mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 3; may june 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and management. a variety of sensors, a variety of transmission networks and protocols are applied to realize a laboratory security system based on the internet of things, which provides a new way of thinking for laboratory security management and ensures that the laboratory can maximize its service for teaching and scientific research. acknowledgements this work is supported by guiding science and technology plan project of dandong city in 2022 (liaodong university united technology): intelligent laboratory security management technology and system based on internet of things. references w. l. zhuang. design and research of internet of things technology in laboratory security protection system [j]. electronic test, 2022, 36(09): 119-121+99. j. liu. application of internet of things technology in laboratory safety monitoring[j]. journal of shaoxing university, 2019, 39(01): 110-114. w. w. han. research on wireless network application based on zigbee technologyj]. information recording materials, 2022, 23(10): 233-236. b. l. shi, g. wang, h. x. zhang, y. j. zhang. strain data acquisition system based on zigbee wireless network [j]. instrument technique and sensor, 2020, 57(01): 79-82. x. xu. rfid technology in the internet of things[j]. modern industrial economy and informationization, 2023, 13(03): 119-121. l. li. study on the development and application of internet of things based on rfid technique [j]. shanxi electronic technology, 2016, 44(06): 38-39. b. l. shi, x. s. zhang, x. l. chen. application of internet of things technology in laboratory safety management [j]. research and exploration in laboratory, 2019, 38(03): 273-276. q. h. lou. application of internet of things technology in laboratory security management[j]. computer programming skills & maintenance, 2022, 29(01): 169-171. g. x. cui. design of laboratory safety management system based on the internet of things[j]. research and exploration in laboratory, 2015, 34(03): 287-290. n. qin. research on university laboratory security system under internet of things environment [j]. low carbon world, 2015, 5(32): 153-154. mailto:topacademicjournals@gmail.com microsoft word 2.docx academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset quality control along the baku pipeline: chemical profiling of water samples dr. farid aliyev, prof. leyla hasanovna mammadova, dr. elchin jafarov and prof. nigar guliyeva baku state university, azerbaijan abstract: water pollution is a major environmental problem that can have a significant impact on human health and the environment. this paper reviews the causes, effects, and prevention of water pollution. the paper also discusses the importance of water quality monitoring and management. keywords: water pollution, environmental pollution, human health, environmental impact, water quality, water management 1. introduction environment is an essential element of human existence. it is a result of interference of natural elements – earth, air, water, climate, biosphere – with elements created by human activity. all these interact with/and influence the existential conditions and the possibilities for future development of society. to protect the environment, mainly affected areas must be identified, assessed the degree of damage, and determined the causes that have produced these imbalances. it is necessary to preserve the quality of the environment mainly throughout reducing negative effects of human activities. potentially toxic metals resulting from anthropogenic activities cause severe disturbance of ecosystems [1, 2]. water pollution is a complex process that leads to changes in water composition, aquatic flora and fauna, and may result in a poor condition, water quality for economic and recreational use, being dangerous to human health [3-4]. importance of trace metal concentrations evidence in natural waters and/or environment is growing for the pollution monitoring studies. traces of metal ions have important roles in a wide spectrum of functions of life. some of these toxic trace metal levels are high, such as poisoning by fe, pb and ni affects the central nervous system. heavy metals presence in nature usually is not dangerous for the environment because they are present only in very small quantities [5]. heavy metals are pollutants in the environment only if it’s present in large quantities (this fact is usually attributed to industrial activities). the natural water analysis for physical, chemical properties including trace element contents are very important for public health studies. these studies are also a main part of pollution studies in the environment [1-5]. also, investigations of the quality of drinking water samples have been continuously performed by researchers around the world. the determinations in drinking water have been performed using classical analytical techniques including titrimetric, gravimetric and modern instrumental techniques such as atomic absorption spectrometry (aas), inductively coupled plasma-mass spectrometry (icp-ms), uv-vis spectrophotometer, etc. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset because of the low cost and easiness in usage, inductively coupled plasmamass spectrometry is the main instrument for the determinations of the trace heavy metal ions in drinking waters in the analytical chemistry laboratories [6-7]. now icp method is sensitive and convenient method for the determination of metals in water and wastewater samples. 2. experimental 2.1. apparatus an icp source consists of a flowing stream of argon gas ionized by an applied radio frequency field typically oscillating at 27.1 mhz this field is inductively coupled to the ionized gas by a water-cooled coil surrounding a quartz “torch” that supports and confines the plasma. the sample aerosol is injected directly into the icp, subjecting the constituent atoms to temperatures of about 6000 to 8000°k. inductively coupled plasma mass spectrometer includes a mass spectrometer, detector, an icp source, mass flow controllers for regulating icp gas flows, a peristaltic pump for introducing samples and a computerized data acquisition and instrument control system. 2.2. general discussion in this method, analysts introduce sample material to an argon-based, hightemperature radio frequency plasma, usually via pneumatic nebulization. as energy transfers from the plasma to the sample stream the target elements dissolves, atomizes and ionizes. the resulting ions are extracted from the plasma through a differential vacuum interface and separated based on their mass-to-charge (m/z) ratio by a mass spectrometer. this method has been demonstrated to be suitable for aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, selenium, silver, strontium and zinc. (table 1.) table 1: recommended analyte masses and i̇nternal standards element analytical mass recommended internal standards interference calculation beryllium 9 li c*6 aluminum 27 sc c27 chromium 52 sc c52 manganese 55 sc c55 cobalt 59 sc c59 nickel 60 sc c62 copper 63 sc c63 zinc 66 ge c66 arsenic 75 ge c75-3.127(c77-0.815*c82) selenium 82 ge c82-1.008696*c83 silver 107 in c107 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cadmium 111 in c111-1.073-c108-0.712*c106 antimony 121 in c121 barium 137 th c135 lead 208 th c208+c206+c207 2.3. materials and reagents this study proposes to investigate the quality of drinking waters used for human. samples were taken from oguzgabala-baku water pipeline that supplies absheron-peninsula with drinking water. water samples were collected in high density polyethylene containers previously water samples were stabilized with ultrapure nitric acid (0.5%) reagents and standards a. acids: 1. nitric acid hno3, 2. nitric acid hno3, 1+1: add 500 ml hno3, 500 ml deionized water 3. nitric acid (v/v) 2%: 20 ml hno3 100 ml deionized water and dilute to 1l 4. nitric acid (v/v) 1%: 20 ml hno3 100 ml deionized water and dilute to 1l b. reagent water c. stock, standard and other required solutions 1. internal standard stock solution: germanium, indium, lithium, scandium and thorium are suggested as internal standards add enough internal standards to all samples, standards and quality control (qs) samples. 2. instrument optimization/tuning solution: containing beryllium, cadmium, cobalt, copper, germanium, indium, rhodium, scandium, terbium, thallium, barium, cerium, magnesium and lead. prepare this solution in 2% nitric acid. this mix includes all common elements used to optimize and tune various icp_ms operating parameters. it may be possible to use fewer elements in this solution, depending on the instrument manufacturer’s recommendations. 3. calibration standards: a five standard calibration is recommended from 0 to 100 µg/l e. argon: use a pre purified grade of argon unless it can be demonstrated that other grades can be used successfully. pre purified argon is usually necessary because technical argon often contains significant levels of impurities. 3. results and discussion 3.1. calibration curve a five standard calibration is recommended from 0 to 100 µg/l. other calibration regimens are acceptable if the full suite of quality assurance samples and standards is run to validate any method changes. fewer standards may be used and a two-point blank/mid-range calibration technique commonly used in icp optical methods should also produce acceptable results. calibrate all analyses using the selected concentrations. prepare all calibration standards and blanks in a matrix of 2% nitric acid. add internal standard mix to all calibration standards to provide appropriate count rates for interference correction. table 2 presents the concentrations of metals that were determined in water samples taken from the oguzgabala-baku water pipeline. sample metal concentrations µg/l mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset al cr fe co ni cu zn as cd ba pb sample 1 16.79 0.53 13.57 0.19 1.89 3.89 14.2 1.21 0.57 95.6 1.63 sample 2 11.7 0.46 6.99 0.018 1.83 1.46 2.93 0.19 123.3 3.0 the drinking water samples were analyzed by inductively coupled mass spectrometry. the concentrations of metals ions give in table 1. the lowest and highest levels of elements detected ranged between 0.19 µg/l for cobalt and 1357.3 µg/l for iron. the highest levels of trace heavy metals ions were found in the first sample/ as can be seen in table 1. in this sample al, cr, fe, co, zn, as concentrations were found to be 167.9 µg/l, 0.53 µg/l, 1357.3 µg/l, 0.19 µg/l, 14.2 µg/l, 1.21 µg/l. arsenic is widely distributed in the environment because of its natural and anthropogenic source [8]. concentrations in the drinking water samples were in the range 0.19-1.21 µg/l. the lowest and highest values were in second sample and first sample. the highest iron level was found in first sample as 1357.3 µg/l. lead is one of the most abundant heavy metals in nature. it is an essential nutrient but could be also toxic for humans [12]. most important anthropogenic source of lead in the environment is combustion of gasoline with lead. lead is discharged by vehicles into air them adsorbed from the air by environmental samples such as soil and plants [9-10]. in environmental lead suffers lead changes and find that the pb2+ ion or as insoluble lead compounds. maximum permissible limit for lead in drinking water is 0.01 µg/l and 10µg/l(for who and ec 98/83 must be added). the levels of lead in the samples were in range of 1.63-3 µg/l. the highest concentrations were in second sample. aluminum is an essential nutrient for humans. water analysis showed concentration in the 11.7-167.9 µg/l. zinc is present in natural waters in concentrations lower than the sewer water, which comes from human activities related to galvanizing zinc and copper alloys or other metals. recommending that zinc concentration in drinking water to be less than 3 µg/l. concentrations in the drinking water samples were in the range 2.93-14.2 µg/l. chromium is another omnipresent element, not only because of its nature, but also due to its several anthropogenic sources, mainly coming from its large application in industrial fields. the concentration of cr was in the range of 0.46-0.53 concentrations in the drinking water samples were in the range 0.19-1.21 µg/l.copper could be present in water in ionic form or in complex organ mineral. the highest concentrations of copper were obtained in first sample (up to 3.89 µg/l.) comparison the concentrations of metals in the samples have been shown in figure 1. the highest concentration of cadmium, arsenic, copper, and zinc were obtained in first sample. but the highest concentrations of lead were obtained in second sample. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: comparison the concentrations of metals the concentrations of metal ions in the drinking water samples from oguzgabala-baku were within the permissible limits of the world health organization. the permissible limits of metals ions for 98/83/ec and who were given in table 3. table 3: the permissible limits of metals ions in the drinking water (for 98/83/ec and who) elements unit concentration (98/83/ec) concentration (who) cobalt µg/l chromium µg/l 50 50 cadmium µg/l 5 3 arsenic µg/l 10 10 lead µg/l 10 10 nickel µg/l 20 70 copper µg/l 2 2 zinc µg/l 3 4. conclusions icp-ms method is available and adequate to identify and quantify metals present in natural and drinking waters at trace levels, which are of particular relevance for toxicity control regions, may have been contaminated by toxic metals. comparison the concentrations of metals in the drinking water samples with permissible limits of the world health organization show that concentrations of co, cr, cd, in the both example under permissible limits. concentrations of copper and zinc contained in 1.46-3.89 µg/l and 14.2-2.93 µg/l. in the first sample concentration of copper, nickel and lead is high from permissible limit. concentration of zinc in the first sample is high from permissible limit, but in the second sample below the limit. (figure 2) 0 5 10 15 1 2 3 4 5 6 7 8 sample 1 sample 2 co cr cd as pb ni cu zn mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2: comparison the concentrations of metals with 98/83/ec directive and who acknowledgements the authors are grateful for the financial support of the baku state university and also would like to thank “azersu” ojsc. references v. marmoreal, m. d. galindo-riana, m. garcia-vargas, m. d. granados-castro. journal of hazardous materials 162, 823–836, (2009) m. a. m. abdullah. environ. monet. asses 146, 139–145, (2008). v. novotny. water quality – diffuse pollution and wastewater management. 2ndedition, john wiley and sons, inc., 43–50, (2003). d. florescu, r. e. ionete, c. sandru, a. iordache, m. culea. rom. journ. phys., vol. 56, no.7–8, 1001–1010, (2011). c. stihi, c. radulescu, g. busuioc, i.v. popescu, a. gheboianu, a. ene. rom. journ. phys., 56,no.1–2, 257–264, (2011). soylak m., elci l., dogan m. kayseri cevresindekiakarsulardabazikatyonveanyonlarintayini, marmara universitesi fen basset j., denney t.c., vogel's textbook oof quantitative inorganic analysis, longman, london, 1983. j. ahmed baig, t. gull kazi, a. qadir shah, g. abbas kandhro, h. imran afridi, m. balalarain,m. khan jamali, n. jalbani. ecotoxicology and environmental safety 73, 914–923, (2010). soylak m., eserelementlerveinsan (in turkish), populer bilim dergisi, 8, 47, 2001. 0 cr cd as pb ni cu 0 10 20 30 40 50 60 70 80 1 2 3 4 5 6 7 simple 1 simple 2 98 /83/ec who mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset asubiojo o.i, nkono n.a, ogunsua o. a, oluwole a.f, ward n.i, akanle o. a, spyrou n.m. trace elements in drinking and groundwater samples in southern nigeria, sci. total environ, 208, 1, 1997. soylak m, elci l. solid phase extraction of trace metal ions in drinking water samples from kayseri turkey, j. trace microprobe techn, 18, 397, and 2000 bilimleri dergisi, 9, 85, 1992. ballinger d.g. methods for chemical analysis of water and wastes, epa, ohio, 1989. world health organization (who) guidelines for drinking water quality, 1-2, 1983. soylak m, divrikli u, saracoglu s, elci l. monitoring trace metal levels in yozgatturkey: copper, iron, nickel, cobalt, lead, cadmium, manganese and chromium levels in stream sediments, polish journal of environ mental studies, 11, 47, 2002. c.voica, m. h. kovacs, a. dehelean, d. ristoiu, a. iordache icp-ms determinations of heavy metals in surface waters from transylvania 2011. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset enhancing the performance of ultra mobile broadband network using adaptive interference and noise cancelling technique 1ezema d. c, 2eke james and 3ifeagwu e.n. 1&2department of electrical & electronic engineering, enugu state university of science and technology (esut), enugu state, nigeria. 3federal university otueke (fuo), bayelsa state, nigeria. doi: https://doi.org/10.5281/zenodo.13991006 abstract: this paper focused on enhancing the performance of ultra mobile broadband networks using adaptive interference and noise cancelling technique. the test van used during the measurement was driven in the direction of one antenna sector, though there were overlaps from two sectors at some points. in addition, the global positioning system (gps) was used to measure the distance between the base station and the mobile station, i.e., the transmitter–receiver (t-r) separation distances starting from 100m to several multiples of 100m. during the drive test, four numbers of functional base stations were seen and the ray tracer helped to pick the signal of the network of choice amongst several signals from various networks. this is achieved by setting the appropriate frequency on which the desired network operates. as the investigative base station operates at a frequency of 878.87mhz, the ray tracer helped to locate the base station that transmits at that particular frequency. however, the signal strengths of the signals were recorded at various points and the distance of these points from the reference point of the base station also recorded. results obtained showed that using adaptive interference and cancelling technique yielded a bit error rate in the range of 10-2 to 10-3. keywords: broadband, noise cancelling, compensating, global positioning system (gps). 1.0 introduction in ultra-mobile broadband communication network, the system throughput as well as the throughput at a cell edge is among the most important evaluation measures for the requirements on the system performance (lee w., 2011). among many candidates on the multiple access schemes, frequency hopping orthogonal frequency division multiple access (fh-ofdma) has been considered as one of the promising packet-based transmission techniques because fh-ofdma can easily deal with the frequency selective fading channel and provide not only inner-cell orthogonality but also inter-cell interference (ici) averaging effect. thus, it enables us to construct a cellular network with a frequency reuse factor equal to one (cox d.c, 2012). however, the ici averaging effect would not work properly in case that there exist interferers with differently allocated power loading in adjacent cells, which makes the ici pattern highly non-uniform (ellingson, s.,2001). therefore, it is very important to manage such non-uniform ici, especially at cell edge. several ici mitigation techniques have been proposed to provide reliable communication to cell-edge users. traditional frequency reuse schemes, such as a reuse factor 3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset deployment, can significantly reduce the average ici. however, it sacrifices accessible frequency resource in each cell in order to manage the interference levels so that the overall system capacity is quite limited. another method proposed to handle the ici is the coordinated symbol-repetition scheme (bells, 2006). in this method, a repeated symbol mapping in the frequency domain is coordinated to be identical among adjacent cells. then a user equipment can perform interference cancellation by using a minimum mean square error (mmse) receiver in the frequency domain. this method can mitigate the ici and increase the number of allowable interferers. but this scheme also needs additional resource due to the repetition, which ends up with limiting the system performance as well. as an advanced version of the traditional frequency reuse scheme, two frequency reuse schemes have been proposed. one is the partial frequency reuse (pfr) scheme, and the other is the soft frequency reuse (sfr) scheme (rappaport, 2010). the pfr scheme partitions the whole frequency into two parts, a part with reuse factor 1 and the other with reuse factor less than 1. the reuse factor 1 part is used only by inner cell users and the other part can be used by cell edge users. this scheme greatly solves the limitation of the traditional frequency reuse scheme. however, there still exists inefficiency due to the part for the cell-edge users. in the sfr scheme, a part of the whole frequency is reserved for the cell edge users and is kept being orthogonal among adjacent cells. the remaining frequency band can be used only by inner cell users for each cell. the transmission power can be amplified on the reserved band for the cell-edge users and inner cell users can also use this reserved frequency band. therefore, the sfr scheme can achieve the reuse factor of 1. but, both the pfr and the sfr schemes need a strict cell planning, which is very hard for a practical system (darren d. chang and olivier l. de weck,). if an irregular cell pattern is given, such frequency reuse schemes requiring a strict cell planning would lead to an inefficient use of the spectrum. in a soft channel reuse (scr) scheme using an erasure decoding (ed) method with downlink power control was proposed to handle;/the non-uniform ici for downlink fhofdma systems. in this scheme, no strict cell planning is required due to its sub channel structure. it considered a multi cellular downlink ofdma system where a power control is performed such that a base station (bs) can use full power for up to a pre-determined number of sub-channels allocated to cell-edge users while the rest of power is used for the sub channels allocated to inner-cell users. so all frequency resources can be utilized in each cell regardless of the cell shape. by erasing highly interfered symbols, it was shown that partially interfered signals can be effectively decoded without any prior knowledge on ici. however, the ed method is only applicable to the case where a few sub-channels are allowed for the outer cell region such that ici is concentrated to a small fraction of subcarriers in the sub-channel. as the number of cell edge users increases and demands more sub-channels, the performance of the ed scheme is deteriorated. in this work, we propose an adaptive interference and noise cancelling technique for ultramobile broadband network. the key operational features of the ultra-mobile radio interface are support for high data transmission: 384kps with wide area coverage, 2mbps with local coverage and high service flexibility: support of multiple parallel variable rate services on each connection. 2.0 interference on ultra-mobile network (umb) the type of interference experienced in ultra broadband network is the multiple access interference or the multiuser interference. multiple access interference (mai) is a factor, which limits the capacity and performance of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ultra band networks. in contrast to fdma and tdma techniques which are frequency bandwidth limited, all users transmit in the same frequency band and are distinguished at the receiver by the user specific spreading code. all other signals are not de-spread because they use different codes. these signals appear as interference to the desired user. as the number of users increase, the signal to interference ratio (sir) decrease until the resulting performance is no longer acceptable. thus, this multi–user interference must be reduced to achieve higher capacities. there are several ways of improving ultra broadband communication network. they are: receiver beam forming, voice activation technology, power control, multiuser detection, using rake receivers and soft handoff. a simple equation for the uplink capacity u of a single ultra broadband cell is given by (m. viterbi, a. j. viterbi (2008):    gnewgu ob 2/1  (1) where the value of 𝐸𝑏 𝑁0⁄ represents that required for adequate link performance. the scalar σ2 is the background noise power and s is the received signal power for each user. finally, g is the ratio of the antenna gain for the desired user to that of interfering user in that cell. the value of g depends on the beam pattern for each user, but will roughly be proportional to the array size m. as a result, antenna arrays can improve the capacity in two ways: 1. increasing the antenna gain g and hence the array m. this reduces the average level of interference from each user in the cell, permitting a capacity increase. 2. reducing the required, 𝐸𝑏 𝑁0⁄ antenna array can provide increased space diversity at the base station, which can permit the receiver to operate at lower power signal. this increases the tolerance of the receiver to multiple access interference. 3.0 materials and methods in this section, we presented the characterization of the network under study. this was done by firstly carrying out measurement of the received power in db. this is to ascertain the efficiency of the network. the measure data will now be used to develop the model for the network. 3.1 measurement environment in this paper, field measurements were performed in port harcourt city, the capital of rivers state of nigeria using the existing wireless network of the glo network which is a n ultraband base network. this helps to identify the nature of the typical propagation environment for the base station drive route. the drive test was intended to cover base station, using spectrum monitoring equipment such as ray tracers and spectrum analyzer. the port harcourt environment consisted of a sparsely built up environment and small houses with two to three floors and back yards. the houses were of clay bricks and metal roofs. the environment is made up of farm lands and few bushes around. measurements of received signal strength will be made at intervals of 100m up to 700m from a reference point on the transmitting base station. the base station that was used for the research work is mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset shown below the base station belonging to ultra band network located at a location with latitude 6˚ 45’n and longitude: 4˚30’e of port harcourt city. the base station carrying sectorized antenna provides coverage for a large area such as suburban environment like port harcourt. the base station height is 36m and has a carrier frequency of 878.87mhz. 3.2 method of data collection the measurement carried out on the first scene consist of a base station and a receiver antenna mounted on the roof top of the spectrum monitoring van housing the spectrum monitoring equipment. the base station antenna height is 36m while the mobile antenna was mounted on a 3m high test van. the carrier frequency of the network under consideration is 878.87mhz. the test van used during the measurement was driven in the direction of one antenna sector, though there were overlaps from two sectors at some points. in addition, the global positioning system (gps) was used to measure the distance between the base station and the mobile station, i.e., the transmitter–receiver (t-r) separation distances starting from 100m to several multiples of 100m. during the drive test, four numbers of functional base stations were seen and the ray tracer helped to pick the signal of the network of choice amongst several signals from various networks. this is achieved by setting the appropriate frequency on which the desired network operates. as base station operates at a frequency of 878.87mhz, the ray tracer helped to locate the base station that transmits at that particular frequency. however, the signal strengths of the signals were recorded at various points and the distance of these points from the reference point of the base station also recorded. these distances in kilometers were obtained using global positioning system (gps). generally speaking, the received signal strength from a base station decreases with distance when measured at various points along a radial path leading away from the base station. ideally, signal-strength measurements would be made by monitoring and recording the signal received by a mobile unit in the van as it moves away from the base station. the measurements were carried out between 8.00am till 6.00pm each day for the whole period of measurement. 3.3. experimental setup in other to provide good analysis of the network system that will ensure such good quality of service to users, quality of service parameters which will help in the system analysis are sought for. to achieve this, real time measurements were carried out and the data obtained were used to ascertain the efficiency of the existing infrastructure. it shows the base station transceiver (bts) from where the transmitted signals emanate. the transmitted signal strengths are measured with the help of ray tracer. ray tracer are software developed to indicate the presence of a signal and also its strength at a particular spot. the quality of the received signal in any channel can be ascertained by the ray tracer. while the ray tracer gives the level of signal strength, the global positioning system (gps) shows the distance of the mobile unit or another transmitting base station from the base station under consideration. the gps can also be used to measure the angular locations of the mobile unit with respect to the transmitting base station. the entire data that were measured were recorded and analyzed using spectrum mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset analyzer. real time measurements of received signal strength, distance of mobile station (ms) from base station (bs), and angle of arrival (aoa) signal from the base station are carried out at a test bed. the results obtained were necessary in the simulation and performance analysis of adaptive antenna array in ultra mobile broadband network. 3.4 characterization and development of the model for the network under study table 1: technical summary for ultra-mobile broadband network (umb) channel bandwidth 5mhz frequency band 1920mhz-1980mhz(uplink) 2110mhz-2170mhz(downlink) duplex mode fdd and tdd chip rate 3.84mcps frame length 10ms modulation qpsk carrier spacing 4.4mhz-5.2mhz number of chips/slot 2560chips channel bit rate 5.7mbps channel coding convolutional and turbo codes physical layer spreading factors 4-256(uplink),4-512(downlink) number of base station codes 512/frequency power control period:time slot 1500hz rate power control step size 0.5,1,1.5 and 2db(variable) power control range 80db(uplink),30db(downlink) multirate variable spreading and multicode downlink rf channel direct spread pulse shaping root raised cosine, roll off=0.22 data types packet and circuit switch receiver rake channel id rx signal distance gps ray tracer bts figure 3.3: block diagram of the test bed setup mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 2: average of the received signal strength measurement carried out (cell site: 641, frequency, f=878.87mhz, transmitted power, tx =44.4dbm) distance (m) rss (dbm) 100.00 -68.64 200.00 -75.64 300.00 -94.99 400.00 -94.89 500.00 -98.73 600.00 -104.09 700.00 -107.29 table 3: average of the measurement of received signal strength carried out (cell site:641, frequency, f =878.87mhz, transmitted power, tx =44.4dbm). time of measurement:8.00am -6.00pm distance(m) rss (dbm) 100.00 -67.94 200.00 -74.16 300.00 -86.84 400.00 -87.04 500.00 -91.64 600.00 -99.33 700.00 -103.13 3.2.1 characterization of the ultraband mobile network radio under study. in order to characterize the mobile radio propagation environment under study, we made use of equation of pathloss to obtain the pathloss exponent, of the test bed environment and empirical propagation pathloss model for portharcout. therefore, in order to completely characterize a propagation environment under study, the following parameters must be known: 1. received signal strength obtained from field measurement 2. the pathloss exponent, n,of the characterized environment 3. an empirical propagation path loss model for the test bed environment. (i) determination of pathloss exponent (n) of ultratest bed environment equation (1) predicts that the mean path loss pl(di) [db] at a transmitter receiver separation di is (feher,2006): pl(di) [db] = pl(d0) [db] + 10n log10( 𝑑𝑖 𝑑0 ) (2) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset where n = pathloss exponent pl(d0) = pathloss at known reference distance d0. that is: n = {𝑃𝐿(𝑑𝑖)− 𝑃𝐿(𝑑0)} 10𝑙𝑜𝑔10( 𝑑𝑖 𝑑0 ) (3) (ii) empirical path loss model for mobile radio propagation environment. the path loss model for free space is given by equation (3) (gupta, et al, 2009) lpfs (db) = 32.44 + 20 log10 (fc) + 20log10 (di) (4) where lpfs is the free space path loss fc is the carrier frequency in (mhz) di is the distance between the base station (bs) and mobile station (ms) in (km). the hata path loss model for urban and suburban environment is given in equation (5) and (6) respectively. lpu (db) = 69.55 + 26.16log10(fc )+ (44.9-6.55log10hb) log(di)-13.82log10(hb) α (hm) (5) lps = lpu – 2[log10( 𝑓𝑐 28 )]2 – 5.4 (6) where; lpu is the pathloss prediction for urban area in db, lps is the pathloss prediction for suburban area in db, α (hm) is the correlation factor for mobile station antenna height in db, hb is the height of bs (km). hm is the height of ms.the correlation factor α (hm) for suburban is given as: α (hm) = [1.1log10fc – 0.7]hm – [1.56logfc – 0.8] (7) (iii) computation of pathloss exponent using equation (3) to obtain the pathloss, n, of the test bed environment where, pr ,is the received signal strength values in dbm , pt is the transmitting power in db, pathloss pl is the difference between pt and pr. let n, denote the numerator values and d denote denominator values, we computed the pathloss exponent of the test bed area as follows: d=[100,200,300,400,500,600,700] pt=44.4db pr=[-67.94 -74.16 -86.84 -87.04 -91.64 -99.33 -103.13] pl(d)=pt-pr=44.4 -[-67.94 -74.16 -86.84 -87.04 -91.64 -99.33 -103.13] pl(d)=[112.34 118.56 131.25 131.44 136.04 143.73 147.53] =[112.34 118.56 131.25 131.44 136.04 143.73 147.53]-[112.34] =[0 6.22 18.91 19.10 23.70 31.39 35.19 ] n =134.51 d=∑ [10log10 [1 2 3 4 5 6 7 ]] d=0+3.01+4.77+6.02+6.99+7.78+8.45 =37.02 therefore, n= n/d pathloss exponent, n =3.63 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the pathloss exponent, n, which characterizes the propagation environment under study (test bed area/environment) is obtained from the measured data and is 3.63. (iv) developed ultramobile broadband propagation pathloss model for test bed area. using equation (8) and equation (9) and substituting fc =878.87mhz, hb= 0.036,hm=0.0018, α (hm)=3.99,we obtain the value for the pathloss model for portharcourt as: lpu(db) = 69.55 + 26.16log10(878.87)+(44.9-6.55log10(0.036)) log(di)-13.82log10(0.0018) 3.99 (8) lpu(db) =104.63+54.36log(di) (9) from equation 6, we obtain: lps = 104.63+54.36log(di) – 2[log10( 878.87 28 )]2 – 5.4 (10) lps (do)=94.74db. but, re-arranging equation (3.1), so that: pl(di) [db]=lp(di)=empirical pathloss model for portharcourt pl(d0) = lps(do) = pathloss for portharcourt at known reference distance d0 n = 3.63 =pathloss exponent. therefore, the empirical path loss model for portharcourt is: lp(di)=94.74 + 36.3log(di) (11) 3.4 the propose developed mathematical signal model. a possible method of predicting the received signal power (rss) for the test-bed environment is propose by (chipcon,2007) as shown in equation rssi = -10n log10( 𝑑𝑖 𝑑0 ) + a (12) where; rssi = the signal power at the receiver n= pathloss exponent di = distance between the transmitter and receiver do= reference distance from the transmitting base station i.e.100m a = the rss at a hundred meter distancefrom transmitting base station the value for the pathloss ,n, exponent was computed to be 3.63. the value for a; which is the received signal power at 100 meter from the transmitter, and is found to be -67.94 dbm. putting these values back to the model represented by equation (12).and re-arranging equation (12), so that y denotes rssi and x denote 𝑑𝑖 𝑑𝑜 , our propose model which can be used in predicting received signal strength is: y = −36.3log10 𝑥 – 67.94 (13) equation (13) was used in predicting the received signal strength of the test bed environment. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 0 5 10 15 20 25 30 35 40 10 -2 10 -1 10 0 antenna element m=4 and rake fingers=4 eb/nb[db] b e r conventional beamforming lms algorithm 4.0 results and discussions comparison of bit error rate performance of ultra-broadband network using adaptive interference and cancelling technique algorithm and conventional beam forming algorithm figure 2 show the comparison of the receiver average ber performance of ultra-mobile broadband network with lms adaptive beam forming algorithm and conventional beam forming algorithm. the mean ber is improved with the lms adaptive beam forming compared to the conventional beam forming algorithm. the ber of the lms is of order 10-2 at eb/no≤ 10db figure 2; ber vs. eb/no performance of ultra-mobile broadband network using lms adaptive beam forming algorithm compared with conventional beam forming algorithm. 5.0 conclusion the improvement of ultra mobile broadband network using adaptive interference and noise cancellation technique was investigated for a conventional narrow band beam former by varying the array elements and the number of interferers which revealed significant improvement as these numbers increase for odd numbered arrays. hence, interference is greatly suppressed as the odd numbered array elements increases. from the charts, it was observed that the signal-to-interference and noise ratio depends on the number of antenna element, the inter-element spacing between the arrays and the number of interferers. there was great improvement in the sinr when odd numbered elements were used with inter-element spacing of d=0.5 in the presence of large interferers. adaptive antenna as observed from our analysis showed greater improvement in the sinr over sectorized antenna in the presence of large interferers. finally, improving the interference suppression and noise reduction capabilities of any antenna system in the presence of large interferers, increases the capacity of that system deploying such an antenna. therefore, adaptive antenna proposed here will increase capacity of the ultra mobile broadband , thus making the network to accommodate more subscribers per base station. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 5; september-october 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references lee w.y.c., (2011), “effects of correlation between two mobile radio base station antennas”, ieee transactions on communications, vol. 21, no. 11, pp.1214-1224. cox, d.c., (2012), “delay doppler characteristics of multipath delay spread and average excess delay for 910mhz urban mobile radio paths”, ieee transactions on antennas and propagation vol. 20, no. 5, pp. 625-635. ellingson, s., (2001), “smart antenna technologies”, ieee workshop, vol 3,pp. 106-110. rappaport, t.s., (2010), “smart antennas: adaptive arrays, algorithms and wireless position location”, ieee press. pg 800-805. wells, m.c., (2006), “increasing the capacity of gsm cellular radio using adaptive antennas”, ieee proceedings, vol.55, no. 12., pp 2143-2159. abdullah aburomeh, (2009) “capacity analysis of cellular cdma systems” (ece 559 project) a. m. viterbi, a. j. viterbi (2008) “erlang capacity of a power controoled cdma system” darren d. chang and olivier l. de weck, 2005‘basic capacity calculation methods and benchmarking for mftdma and mf-cdma communication satellites. international journal of satellite communications and networking; 23:153–171. k. s. gilhousen et al., 1991 “on the capacity of a cellular cdma system,” ieee trans. veh. technol., vol. 40, pp. 303–312, mailto:topacademicjournals@gmail.com article ludovia (de 22 000 à 30000 caractères espaces compris) academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset optimizing the rear-disconnected steering trapezoid for fsae racing cars hanqi wang, bo wu, xiaolong cheng, yongjun mao school of mechanical & power engineering, harbin university of science and technology, harbin 150006, china abstract: the steering system of fsae racing car plays a vital role in maintaining the direction and stability of the car. the design of the steering trapezoid is an important component of the steering system, and the postdisconnected steering trapezoid has been analyzed and optimized in this study. to improve the steering behavior of the car, a mathematical model of the post-disconnected steering trapezoid was developed. the objective function was established using the modified ideal ackerman steering formula, and the geometric relationship between the actual inner and outer corners. additionally, a constraint equation was established to ensure operational convenience of the steering mechanism. matlab was used to find the design variable parameters that satisfied the fatigue strength while ensuring that the actual internal and external angle relationship was maximally close to the ideal ackerman steering. furthermore, the dynamic change of the toe angle of the parallel two-wheeled beating was simulated using adams, to ensure that the car met the stability requirement. the results showed that the optimized post-disconnected steering trapezoid can significantly improve the steering behavior of the fsae racing car. the mathematical model and optimization method developed in this study can provide a theoretical reference for the design of the steering trapezoid in future studies. moreover, this study highlights the importance of considering the fatigue strength and dynamic simulation in the design process of the steering system for fsae racing cars. overall, the optimized post-disconnected steering trapezoid design can improve the stability and steering performance of fsae racing cars, providing better handling during dynamic competition. the proposed method can be applied to the design and optimization of steering systems in various racing cars, making it a valuable contribution to the field of motorsport engineering. keywords: fsae racing car, steering system, steering trapezoid, post-disconnected, ideal ackerman steering, mathematical model, fatigue strength, dynamic simulation, stability requirement. 1. introduction among the components of the fsae, the steering system is directly related to the passing and steering stability of the car. the steering system of the fsae racing car is the mechanism which is used to maintain or change the direction of the car. and it also can ensure a coordinated corner relationship between the steering wheels when the car is turning [1]. in the dynamic competition, the 8-word loop, high-speed obstacle avoidance and endurance race have higher requirements on the stability of the steering system, and the design of the steering trapezoid is a particularly important part of the steering system design [2]. so, a reasonable design of steering trapezoid not mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset only improves the steering ability of the car, but also improves the overall performance of the car to a certain extent, which is of great significance for improving the performance of the car. presently, scholars at home and abroad have deeply analyzed and researched on the structural design of the fsae racing car to the trapezoid from various angles. for example, song xueqian and others established a mathematical model of the front-disconnected steering trapezoidal structure and collected data through an angular displacement sensor to correct the steering angle [3]. shaofei and others realized the design of parallel ackerman geometry steering trapezoid [4]. and zhangkai and others proposed a steering trapezoidal joint optimization design method and improved the speed and corner stability of the fsae racing car [5]. the above research provides different research methods for the steering trapezoid of the car, but the front layout is adopted in the layout of the steering trapezoid, and the research results are not fully applicable to the layout scheme adopted in this paper. so, in this paper we further analyzed and optimized the rear-disconnected steering trapezoid with the steering gear located behind the front axle. 2. methodology 2.1 steering trapezoid scheme selection in the rules issued by the competition, it is clearly stated that the use of steer-bywire steering and electronically controlled steering is prohibited. considering the light weight of the fsae racing car, most of the teams use unassisted mechanical rack and pinion steering gears, which have simple structure, small size, easy to make, etc., can reliably meet the steering task [6]. because of the compact layout of the fsae racing car, in order to ensure good compatibility between the steering system and the independent suspension system, the disconnected steering trapezoid is often used. according to the different positions of the steering trapezoid and the rack and pinion steering gear with respect to the front axle, the arrangement can be divided into four types [1]. and the rear trapezoidal arrangement of the steering gear behind the front axle is simple. so, in this paper we use the rear-disconnected steering trapezoidal powerless mechanical rack and pinion steering gear with the steering gear behind the front axle. we analyze and design the fsae racing car. and its structural diagram is shown in figure 1. figure. 1 rear-displacement steering trapezoidal structure intention of the steering gear behind the front axle mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.2 establishment and analysis of steering trapezoidal mechanism model when the car is turning, in order to ensure that its four wheels are all rolling around the same instantaneous center point without sliding, that is, to meet the ackerman steering [7], the angle of the inner and outer wheels of the front axle should satisfy the relationship as shown in figure 2. figure. 2 ideal ackerman corner according to the geometric relationship, the concrete expression of the ideal inner and outer wheel angles when meeting ackerman steering can be obtained: cotβ0 −cotα0 = k l/ (1) where α0 is the ideal inner wheel steering angle, β0 is the ideal outer wheel steering angle, k is the main pin center distance, and l is the wheelbase. if the self-variation angle is assumed to be the ideal inner wheel steering angleα0 , then the angle of change is the ideal outer wheel steering angleβ0 , the expectation of the variable angle β0 can be expressed as: β0 = arccot cot( α0 − k l/ ) (2) however, in the actual car steering process, the tire will be subjected to the centrifugal force generated during the curve driving, that is, the cornering force. under the action of the cornering force, the tire will have a certain deformation, so that the actual inner and outer wheel angles are smaller than the ideal inner and outer wheel angles. so, it is necessary to correct the ideal inner and outer wheel angles [5]. thus, the ackerman steering correction coefficient ε is introduced to correct the ideal outer wheel steering angle β0 . and the specific relationship between the corrected outer wheel steering angle β * and the ideal outer wheel steering angle β0 is : ε= β α* − 0 ×100% (3) β α0 − 0 then, putting formula (3) into formula (2), we can obtain the expected value of the corrected ideal outer wheel steering angle β * as follow. β ε * = × arccot cot α0 − kl −α α0 + 0 (4) place the selected steering gear on the rear trapezoidal broken rack and pinion steering trapezoid behind the front axle. and after simplification, the mathematical model can be obtained, as shown in figure 3. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure. 3 rear disconnected steering trapezoidal model when steering, the steering gear drives the gear rack to move. and under the action of the tie rod, the inner and outer steering wheels will rotate to generate the steering angle [3]. during the steering process, the tie rod and the knuckle arm are hinged, and only the relative position change occurs between them, and the length of each rod is not change. therefore, according to the geometric relationship between the tie rod and the knuckle arm, we can obtain the relative relationship between the various parameters of the steering ladder structure, which is as follows: before turning, the distance l2 from the break point to the midpoint of the ball joint pin end of the knuckle arm is: l2 = k −2m −l1 ×cosϕ 2 +(l1 ×sinϕ− h ) 2 (5) where l1 is the arm length of the trapezoidal arm that turns to the trapezoidal structure, ϕ is the bottom angle of the steering trapezoid, h is the horizontal distance from the center line of the rack to the center point of the kingpin, and m is the length of the tie rod. when turning, the movement stroke s of one side of the rack is: s =− l2 2 l1 ×sin(ϕ β+ 0 )− h 2 −l1 ×cos(ϕ β+ 0 )+ k −2m (6) when the car is turning, the actual outer wheel steering angle β1 is: 2 l12 + h 2 + k −m β1 = arctan k −2hms + arccos 2× ×l1h 2 + 2k −2−ms −s− l2 22 −ϕ (7) − the actual outer wheel steering angle β1 should be designed as close as possible to the expected value of the corrected outer wheel steering angle β * . when the design value is closer to the expected value of the theoretical value, the car can be closer to the ideal ackerman steering during the actual steering process. in order to objectively evaluate the closeness between the actual outer wheel steering angle β1 and the expected value of the corrected ideal outer wheel steering angle β * , we introduce an objective function f x( ) for evaluating the advantages and disadvantages of the steering trapezoid design. the specific expression is as follows: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset where µ is the correction factor, x is the design variable and x =[m h ϕ l1] t . considering that fsae racing cars are always driven under high-speed conditions, the wear pattern of the tire surface pattern is more serious. when evaluating the design of the steering trapezoid, it is necessary to take into account the influence of tire wear on it. thus, the introduction of the correction coefficient µ makes the objective function f x( ) of the evaluation steering ladder design closer to the actual situation. when setting constraints, we focus on the ease of operation of the steering mechanism. because of the low quality of the fsae racing car and the limitation of the installation space, the fsae racing car generally does not use the steering assist device, which requires the entire steering mechanism to be maneuverable during handling. while in the steering trapezoidal mechanism, the direct influence of the handling of the portability are the length of the tie rod m and the bottom angle ϕ of the steering trapezoid. when the values of the design variables m and ϕ are selected too small, the steering load applied to the tie rods is too large, which is inconvenient for the racer to turn [1]. when the length m of the design variable tie rod is too large, the size of the entire steering trapezoid will increase, which will not only increase the difficulty of the fsae racing steering mechanism, but also cause serious problems with the interference of the front suspension. thus, selecting the length m of the appropriate tie rod and the bottom angle ϕ of the steering trapezoid have important significance for the manipulation and arrangement of the entire steering mechanism. the specific constraints are as follows: m −mmin ≥ 0 mmax −m ≥ 0 (9) ϕ ϕ− min ≥ 0 in the formula, mmin is the general design minimum of the tie rod, mmax is the general design maximum of the tie rod, and ϕmin is the general design minimum of the base angle of the steering trapezoid. according to the design experience, the general design minimum value of the tie rod is mmin = 0.11k , the general design maximum value of the tie rod is mmax = 0.15k , and the general design minimum value of the bottom angle of the steering trapezoid is ϕmin = 70 . at the same time, the entire steering mechanism should also have high transmission efficiency when maneuvering. the steering trapezoidal mechanism is essentially a multi-link mechanism. in the multi-link mechanism, the transmission angle can effectively reflect the transmission quality of the linkage mechanism. thus, the steering angle is further constrained by the transmission angle. in the motion diagram of the steering mechanism designed above, the transmission angle is γ (as shown in figure 3). and the larger the transmission angle γ, the better the work of turning the trapezoidal mechanism. during the steering process, the transmission angle x is constantly changing with the steering angle. in order to ensure the good transmission performance of the steering mechanism [8], the minimum transmission angle of the steering mechanism should be γmin ≥ 40 . considering that the fsae ( ) 2 2 2 2 2 1 2 2 1 0 0 0 2 arctan arccos 2 2 2 % 1100 cot cot k m l h s l h k m m k s l s h fx k arc l ϕ µ ε α α α − + + − − − + − − − − + × × = × − × × − − + (8) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset racing car needs to meet the characteristics of high-speed continuous passage of multiple corners during the competition, the minimum value of the transmission angle of the steering mechanism is put forward here, that is, the minimum transmission angle of the steering mechanism should satisfy γmin ≥ 50 . during the steering of the car (take the turn to the left as an example), when the car reaches the extreme position of the left steering, the relationship between the minimum turning radius dmin and the maximum value βmax of the steering angle of the front outer wheel can be obtained. the specific geometric relationship is as follows: βmax = arcsin dmin l/ 2−a (10) in the formula, a is the main pin offset. through the study of the fsae track, the minimum turning radius dmin = 3m can be found, so the maximum value βmax of the front outer wheel steering angle can be determined. through the geometric relationship, it can be found that the current steering angle of the steering wheel reaches the minimum value γmin when the maximum value of the steering angle of the outer wheel is reached, so the constraint equation for the minimum value γmin of the transmission angle can be obtained. the specific expression is as follows: 2 γmin = arccos l +l − 2k× ×− 2l1ml2−s − h 2 ≥ 50 (11) according to the above analysis, the solution of the steering trapezoidal mechanism is essentially a constrained nonlinear programming problem. under the constraints of the constraint equations (9) and (11), matlab is used to solve the minimum value of the objective function f x( ), which evaluates the advantages and disadvantages of the steering trapezoid design. then we can get the best value of the design variable x . after determining the optimal value of the design variables, the design parameters of the steering gear in the steering structure can be initially selected. in the rack and pinion steering gear, the movement stroke s on one side of the rack and the maximum angle wmax on one side of the steering wheel have the following relationship: 360×wmax (12) s = π× ×m z in the formula, m is the modulus of the steering gear, and z is the number of teeth of the steering gear. the modulus m of the steering gear should not be too small. if it is too small, the meshing point of the rack will be too close to the top of the tooth when meshing, causing the bending stress of the root to be too large, which is prone to chipping. thus, the modulus m of the steering gear is generally 2-3mm [7]. in the selection of the number of teeth z of the steering gear, considering that the diameter of the indexing circle is small, if the number of teeth is too large, there will be a problem of difficulty in processing and low degree of coincidence of gear meshing transmission, and attention should be paid to avoiding the cutting phenomenon. thus, the number of teeth z of the steering gear is generally selected from 8 to 19. the maximum corner wmax of the steering wheel on one side generally requires no more than 10 from the middle to the left or to the right. thus, putting the optimal design variables into the formulas (6) and (12), and according to the above specific requirements for the rack and pinion mechanism parameters, the modulus m of the steering gear and the number of teeth z of the steering gear can be preliminary determined. then, through checking the tooth surface contact fatigue strength of the gear, we can determine the gear parameters that meet the strength conditions. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the specific process of the steering trapezoidal mechanism optimization design is shown in figure 4. figure. 4 steering trapezoid optimization design flow chart 3. results and discussion 3.1 steering trapezoid optimization design according to the rules of the fsae [6] and the design experience of the fsae racing car, the initial values of the design variables and the upper and lower boundary conditions are determined as shown in table 1. table 1 initial value of design variables and upper and lower boundary conditions mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset design variable initial value upper and lower boundary conditions length of tie rod m / mm 190mm 160mm220mm the horizontal distance from the centerline of the rack to the center point of the kingpin h /mm 35mm 30mm-40mm corner of the steering trapezoid ϕ/ 75 60 90 − arm length of trapezoidal arm 75mm 50mm-100mm according to the above analysis of the steering trapezoidal mechanism model, using the fmincon function in the mtalab optimization toolbox, formula (8) is used as the objective function of the solution, and equations (9) and (11) are used as the constraint equations, and table 1 is used as the upper and lower boundary conditions of the design variables. and the optimized design results are shown in table 2. table 2 steering mechanism technical parameter table design variable design value length of tie rod m / mm 200mm the horizontal distance from the centerline of the rack to the center point of the kingpin h /mm 39mm corner of the steering trapezoid ϕ/ 79 arm length of trapezoidal arm l1 / mm 70mm rack travel on one side s /mm 44mm modulus of the steering gear m/ mm 2mm number of teeth of the steering gear z / teeth 13 teeth in order to test the optimization effect of the steering trapezoid design, the relationship between the input angle of the outer steering wheel and the output angle of the inner steering wheel is drawn by matlab, as shown in figure 5. when the angle curve of the actual inner and outer wheels is closer to the angle curve of the ideal ackerman inner and outer wheels, it shows that the closer the fsae car is to the ideal ackerman steering when it is actually turning. it means that the smaller the difference between the two curves is, the better the actual steering effect is. from figure 5, it can be seen that after adopting the optimized design scheme of this paper, the actual corner curve is closer to the ideal corner curve than the initial corner curve. thus, the design of the steering trapezoid in this paper can better match the ideal ackerman steering relationship under the condition of meeting the design requirements and has better steering performance. the parameter design of the steering mechanism not only affects the steering performance of the car, but also affects the steering stability of the car to some extent. during the steering of the fsae, the relative motion of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset steering mechanism and the suspension mechanism changes the toe angle of the wheel. while the size of the toe angle indirectly affects the wear level of the fsae racing tires. thus, in the design process of the steering mechanism, the degree of change of the toe angle during the running of the wheel should be minimized, so that the car maintains good steering stability during the steering process. figure.5 inner and outer wheel angle relationship curve the minimum value of the toe angle change during parallel double-wheel bounce is optimized using the insight module in adams. the optimization result is shown in figure 6. according to figure 6, it can be seen that the toe angle of the wheel before and after optimization is reduced from 1.7957° to 1.4478°. after adopting the design of the steering mechanism of this paper, the degree of change of the toe angle when the wheel is beating can be effectively reduced. thus, from the perspective of dynamics, the optimized design of this paper makes the fsae racing car have higher steering stability when steering and achieves the expected optimization results. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure.6 simulation curve of parallel double wheel bounce toe angle change 4. conclusion in this paper, we analyze and model the rear-disconnected steering trapezoid of fsae racing car and transform the steering trapezoidal multi-link mechanism into a mathematical model. and we modify the ideal ackerman steering formula and consider the effect of the cornering force on the ideal ackerman steering. the objective function is established by the geometric relationship between the modified ideal ackerman steering formula and the actual inner and outer corners, and the operation convenience of the steering mechanism is constrained. after adopting the idea of nonlinear programming, and then determining the upper and lower boundary conditions of the design variables, the initial values of the design variables are continuously changed by matlab software, so that the final design structure can maximally close to the actual internal and external rotation angles under the condition of satisfying the fatigue strength. the adams software is used to simulate the dynamic change of the toe angle of the parallel two-wheeled. it is verified that the steering trapezoidal design given in this paper not only has good steering performance, but also improves the steering stability of the car to a certain extent. and it also improves the dynamic performance of the fsae racing car while driving in a corner. the results of the study provide a certain reference value for the design of the fsae racing steering mechanism. 5. acknowledgement this paper is supported by the harbin university of science and technology college students' innovation and entrepreneurship training program (project no. 201810214162). references jilin university, wang wangyu. automotive design [m]. the third edition. beijing: china machine press, 2016. zhang xiangbo, he yaohua. optimization and simulation of trapezoid steering of rear wheel of fsae [j]. automation & instrumentation, 2017(12):48-54. song xueqian, zhou yuebin, huang cheng. analysis and optimization of fsae racing steering structure parameters [j]. equipment manufacturing technology, 2018(07):73-75+87. shao fei, li chuanchang, xu huayuan. design and optimization of fsae racing car steering trapezoid [j]. journal of shanghai university of engineering and technology, 2018(1). zhang kai, chen pan. joint optimization design of fsae racing car steering trapezoid [j]. shaanxi auto, 2015(4):72-74. organizing committee of rules of china formula university car race. 2018 chinese formula student car competition entry manual [r]. beijing: saec, 2018. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.7, issue 5; september october 2022; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset beijing institute of technology, wang jian. formula university racing design [m]. the first edition. beijing: beijing institute of technology press, 2016. southeast university mechanical engineering group, zheng wenwei. principle of mechanics [m]. the seventh edition. beijing: higher education press, 1997. mailto:topacademicjournals@gmail.com beginning at a very young age, today’s students are schooled at home (and just about everywhere else) by television academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset antioxidants from amazonian vegetables: a potential source of natural medicine mariana a. perez-chavez, juan c. ramirez-gonzalez and luisa d. sanchez-flores national university of the peruvian amazon, iquitos peru abstract: the amazon rainforest is home to a vast diversity of plant species, many of which have been used for medicinal purposes by indigenous peoples for centuries. this study investigated the antioxidant activity of plant species collected from the tamshiyacu-tahuayo communal regional conservation area (acr ctt) in peru. the antioxidant activity of the plant extracts was determined using the dpph assay. the results showed that the plant extracts had significant antioxidant activity, with some extracts exhibiting more activity than commercial antioxidants. the findings of this study suggest that the plant species from the acr ctt have potential as sources of natural antioxidants. keywords: amazon rainforest, medicinal plants, antioxidant activity, dpph assay, natural antioxidants 1. introduction certain amazonian plant species among its many utilities that ethnobotany mentions, is its use as medicinal plants that have been used by the inhabitants of this region since time immemorial and, thanks to the studies of various researchers, it has become known and valued for a proper use of them (duke & vasquez, 1994) the town of tamshiyacu is the capital of the district of sargento lores in the loreto region and its primary forests belong for the most part to the tamshiyacu tahuayo communal regional conservation area of peru (acr ctt). located in zone 18 of the utm projection system, between coordinates 680 075 e, 9 528 176 n and 768 162 e, 9 444 073 n. it has an area of four hundred twenty thousand and eighty hectares with two thousand five hundred square meters (420,080, 25 ha), (gobierno regional de loreto, 2011); (shoobridge, et al., 2004). the antioxidant activity is considered as the sequestration of free radicals, which are found in excess, in the human organism they are considered to cause various pathologies that include aging, cancer, arteriosclerosis and other diseases in humans, (ibarra et al., 2011). the main organic molecules provided by the plant species that manage to sequester these free radicals are mainly phenolic compounds, some alkaloids and vitamins a, e and c, (coronado, et al., 2015). the objective of the present study was to perform the evaluation of the antioxidant activity of the foliar samples of 31 plant species of the amazonian forest of the tamshiyacu locality and to select the three best with high activity, 2. materials and methods 2.1. materials collection of plant material: leaves of 31 plant species were collected in the vicinity of the town of tamshiyacu and are shown in table 1. the exsicatas were deposited in the herrerense herbarium of the research institute of the peruvian amazon (iiap). evaluation of antioxidant activity. with the samples of the dried and powdered leaves, the methanolics extracts were prepared with some concentrations of 0.25; 0.1; 0.05 and 0.01 mg/ml. to determine the antioxidant activity, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset we used the uv/vis spectrophotometer equipment, specturlamb brand 22 pc. (kerlab). in a 1.5 ml polystyrene cuvette, 25 μl of the methanolic extract and 975 μl of 0.1 mmol dpph solution were added, then the absorbance was measured at a wavelength of 517 ηm, the readings were performed for 5 minutes with 30 second intervals, all reactions were performed in triplicate. the inhibition of dpph radical sequestration by increasing solutions of the extracts was determined by the following expression, (sotero et al., 2011). % inhibition dpph = [(ac – am)/ac] 100 where: ac, is the absorbance of the control (0.1 mmol of dpph), and am, is the absorbance of the sample (increasing solutions of the extracts) in a time n. 2.2. methods phenolic compounds: for the extraction of phenolic compounds, the technique of (valls et al., 2000) is as followed: 0.5 g of the sample is weighed and extracted successively with 3 volumes of 25 ml of ethanol acidulated with 1% formic acid. the extract is concentrated in a rotary evaporator at 40 °c. the dry residue is redissolved in a 50% methanol solution acidified with a formic acid solution, and brought to a volume of 10 ml. this is stored for subsequent analyzes. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 1. list of 31 plant species collected in the vicinity of the town of tamshiyacu, loreto-peru. registry collector order/families species georeference utm 1 paa malpighiales/ euphorbiaceae sapium sp. 18m 0714538 9555251 2 paa magnoliales/ myristicaceae virola. sebifera 18m 0714538 9555249 3 paa magnoliales/ annonaceae oxandra sp. 18m 0714501 9555241 4 paa magnoliales/ myristicaceae virola. sebifera 18m 0714495 9557062 5 paa magnoliales/ myristicaceae iryanthera cf. laevis 18m 0714497 9555242 6 paa magnoliales/ annonaceae cymbopetalum cf.longipes 18m 0714451 9555237 7 paa rosales/ moraceae ficus cf. americana 18m 0704508 9560836 8 paa fabales/ fabaceae parkia cf. multijuga 18m 0704522 9560848 9 paa rosales/ moraceae brosimum parinaroides. 18m 0704985 9561001 10 paa gentianales/ apocynaceae couma macrocarpa. 18m 0705215 9561180 11 paa magnoliales/ annonaceae xylopia cf. benthamii 18m 0705289 9561177 12 paa malpighiales/ caryocaraceae caryocar glabrum 18m 0705951 9558757 13 paa magnoliales/ annonaceae guatteria cf. hyposericea 18m 0705964 9558755 14 paa sapindales/ anacardiaceae tapirira guianensis 18m 0705988 9558712 15 paa magnoliales/ myristicaceae virola cf. surinamensis 18m 0706268 9559258 16 paa gentianales/ apocynaceae llacmelleasp. 18m 0711608 9557071 17 paa magnoliales/ annonaceae guatteria cf. flabellata 18m 0711617 9557063 18 paa fabales/ fabaceae dialium cf. guianense 18m 0711612 9557072 19 paa rosales/ moraceae helicostylis cf. tomentosa 18m 0711610 9557062 20 paa rosales/ moraceae helicostylis cf. turbinata 18m 0711623 9557049 21 paa santalales/ olacaceae mnquartia guianensis 18m 0711855 9556913 22 paa laurales / siparunaceae siparuna cf. sessiliflora 18m 0711854 9556909 23 paa rosales/ moraceae ficus sp. 18m 0711842 9556901 24 paa alismatales/ araceae dracontium cf. amazonense 18m 0711830 9556904 25 paa malpighiales/ clusiaceae vismia cf. macrophylla 18m 0711852 9556899 26 paa caryophyllales/ nyctaginaceae neea cf. divaricata 18m 0711864 9556887 27 paa fabales/ fabaceae zygia cf. macribridei 18m 0711868 9556888 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 28 paa fabales/ fabaceae diaium sp. 18m 0706244 9561454 29 paa gentianales/ apocynaceae malouetia cf. naias 18m 0706538 9561642 30 paa magnoliales/ annonaceae unonopsis cf. sitipitata 18m 0706764 9561927 31 paa ranunculales/ menispermaceae curarea cf. toxicofera 18m 0706669 9561534 anthocyanins and total flavonoids: the determination of anthocyanins and total flavonoids is performed by uv/vis spectrophotometry in 1ml of the extract prepared for the phenolic compounds by reading the absorbance at 535 ηm and 374 ηm respectively, after dilution of the samples. to perform the calculations, the molar extinction coefficient of malvidin-3-glucoside is used: 29500 l/mol cm. catechin and proanthocyanidins: it is done by the vanillin test. 0.5 ml of the extract is mixed with 1.25 ml of vanillin in 1% methanol (w/v) and with 1.25 ml of 25% sulfuric acid (v/v) in methanol. the white is prepared simultaneously in the same way, but replacing the vanillin solution with methanol. it is left to rest for 15 minutes and then the absorbance reading is made at 510 ηm. total phenolic compounds: measurement of the folin index is carried out, for which 40 μl of the extract prepared for phenolics are treated, with 0.5 ml of folin-ciocalteau reagent and 2ml of 20% sodium carbonate (w/v), and they are taken to 10 ml. after half an hour, the absorbance reading is carried out at 765 ηm. to establish the calibration, catechin standards of concentrations between 0 100 mg/l are used. alkaloids: the method indicated by shamsa et al., (2008), is used, 5 g dry pulverized sample is weighed and extracted with methanol in soxhlet equipment for 12 continuous hours. the extract was filtered and the methanol was separated in a rotavapor at 45 ºc, redissolved with 2n hcl and then filtered, 1 ml of this solution was transferred to a decanting pear and washed three times with 10 ml of chloroform. the ph of this solution is neutralized with 0.1 n naoh, 5ml of bcg and 5ml of phosphate buffer are added, the mixture is shaken and the complex formed is extracted with 1, 2, 3, and 4ml of chloroform with stirring. the extracts are collected in a 10ml vial and then filled to volume with chloroform, in this solution is proceeded to perform the absorbance reading at 470 ηm. the data are quantified with a standard curve of atropine. chromatographic fractionation and identification of polar molecules by gas chromatography coupled to mass spectrophotometry (cg-ms). the chromatographic fractionation of methanolic extracts, in open column with silica gel no. 100, of the three species with high antioxidant activity was performed, and identification of the molecules by thin-layer chromatography, grouping the fractions with similar molecules, then they were subjected to gas chromatography equipment with mass spectrometry, using agilent technologies 7890ª ® with an agilent 122-5532 db 5ms ® capillary column of 30 m, with internal diameter of 0.25 mm. the initial temperature of the oven was 100 °c/03 min, followed by a ramp of 20 °c/3 min up to 300 °c/19 min; the maximum temperature of the oven was 325 °c. a split injection was used and the helium gas flow was 2 ml/min. the fragments for the analyses were recorded with the parameters for a scan of 50 to 500 m/z, sotero et al., (2016). 3. results table 2 shows the antioxidant activity of the leaves of the 31 plant samples studied, ordered by families, where all the evaluations of the antioxidant activity of this species are summarized, it is observed that the three species mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset that exceed 50 % inhibition of antioxidant activity at a concentration lower than 5.0 mg/ml are, virola sebifera, caryocar glabrum and tapirira guianensis. tables 5, 6 and 7 show the molecules identified by the gc-ms of the extracts of the species virola sebifera, caryocar glabrum and tapirira guianensis, respectively. table 2. percentages of inhibition of the methanolics extracts of the leaves of the 31 plant species under study at different concentrations, using the dpph method. concentration, mg/ml family species 5,0 0,5 0,25 0,1 0,05 0,01 mg/ml mg/ml mg/ml mg/ml mg/ml mg/ml annonaceae oxandra sp. 32,59 10,01 12,11 18,35 18,37 17,67 annonaceae guatteria hyposericea 44,42 10,37 5,55 3,51 3,17 2,80 annonaceae cymbopetalum.longipes 26,19 0,05 0 0 0 0 annonaceae xylopia benthamii 43,70 9,46 0,51 0,43 0 0 annonaceae guatteria flabellata 45,56 26,74 7,10 3,68 2,40 1,51 annonaceae unonopsis sitipitata 3,15 0 0 0 0 0 apocynaceae couma macrocarpa. 19,48 7,18 4,10 3,26 0,55 1,78 apocynaceae llacmelleasp. 42,11 17,09 10,75 10,90 10,90 10,50 apocynaceae malouetia. naias 27,84 9,52 13,27 21,55 0 0 anacardiaceae tapirira guianensis 79.41 23.53 20.59 11.76 11.76 8.82 araceae dracontium amazonense 25,82 12,69 7,72 7,11 7,08 8,50 caryocaraceae caryocar glabrum 74,25 29.41 23.53 14.71 11.76 5.88 clusiaceae vismia macrophylla 23,87 10,43 7,27 6,23 5,83 6,32 euphorbiaceae sapium sp. 40,56 7,03 11,98 10,78 11,88 16,04 fabaceae parkia multijuga 6,82 1,40 2,81 1,50 0,85 0,10 fabaceae dialium guianense 11,41 3,17 2,08 0,71 0,26 0 fabaceae zygia macribridei 11,49 0 0,27 0 0 0 fabaceae diaium sp. 30,48 5,55 4,09 2,11 2,18 2,42 menispermaceae curarea toxicofera 22,85 2,91 1,37 0 0 0 moraceae brosimum parinaroides. 17,89 3,92 0,84 1,33 1,46 0,36 moraceae helicostylis turbinata 22,21 12,94 13,78 2,36 2,85 4,39 moraceae ficus americana 9,85 0 0 0 0 0 moraceae helicostylis tomentosa 13,10 1,99 4,71 4,56 4,67 4,22 moraceae ficus sp. 34,48 23,94 24,97 24,72 18,53 19,23 myristicaceae virola. sebifera 81.08 40 32.43 24.32 8.11 5.41 myristicaceae virola sebifera 43,16 12,25 9,96 6,52 0,94 0,12 myristicaceae iryanthera laevis 35,22 6,42 5,87 -2,54 -5,89 -6,06 myristicaceae virola surinamensis 46,19 16,80 13,06 7,44 8,52 6,57 nyctaginaceae neea divaricata 10,33 0 0,98 0 0 0 olacaceae mnquartia guianensis 42,25 8,38 4,20 1,65 1,41 2,00 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset siparunaceae siparuna sessiliflora 21,32 4,64 2,01 2,03 2,52 2,78 table 3. phenolic compounds present in the leaves of three plant species with a high percentage of antioxidant activity. species anthocyanins flavonoids phenolics catechins and proanthocyanidins mg /100g mg /100g mg/100g mg/100g virola sebifera 71,38 143,90 18580,87 0,16 caryocar glabrum 93,95 144,33 15180,71 0,18 tapirira guianensis 41,94 144,12 11568,78 0,10 table 4. total alkaloids present in the leaves of three plant species with a high percentage of antioxidant activity. species total, alkaloids mg/kg total, alkaloids mg/100g virola sebifera 36,03 3,60 caryocar glabrum n.d n.d tapirira guianensis 74,00 7,40 table 5. molecules found by cg-ms in the methanol fractions of the leaves of the 2paa specie (virola sebifera) f1-2paa nº retention time, min molecules prob. % area 1 9.99 (5a) preganane-3,20a-diol, 14a[4-methyl3-oxo(1-oxa-4azabuten-1,4(diyl)] diacetate 63.4 11.5 2 11.67 4-piperidine acetate, 1-acetyl-5-ethyl-2[3 (2-hydroxyethyl 1h-indol-2-yl] -o-methyl-methyl 66.8 23.2 3 11.35 octadecane, 3-ethyl-5(2-ethylbutyl) 64.0 23.2 4 14.61 1h-inden-1-one, 2,3-dihydro-5,8dimethoxy-3-methyl 64.1 12.1 5 16.62 folic acid 61.8 19.9 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f22paa 1 40.16 2'-methylene, bis 6(1-dimethylethyl) -4methyl-phenol 85.0 0.01 2 42.63 3 ', 8,8', trimethoxy-3-piperidine-2,2'binaphthalene-1,1 ', 4,4'tetrone 70.0 0.01 3 47.70 3,5-di-tert-butyl-4-hydroxyanisole 69.5 98.42 f4-2paa 1 10.91 copaene 88.50 2.73 2 12.12 cariopilene 93.20 12.09 3 14.65 1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1(1methylethyl) (1scis) -naphthalene 91.20 3.08 4 14.77 1,3,3,4-tetrahydro-1,6-dimethyl-4-81methletiy) (1scis) naphthalene 86.60 1.02 5 14.94 3-methoxymethyl.2,5,58a-tetramethyl6,7,8,8a-tetrahydro-5chromene) 76.00 1.65 6 16.33 (-) espatulenol 88.60 7.32 7 16.44 cariopilene oxide 87.90 2.71 8 16.56 globulol 53.00 0.91 9 16.83 8s, 14-cedran-diol, 77.60 1.35 10 17.86 cubenol 85.50 0.59 11 18.11 espatulenol 79.90 1.43 12 18.90 a-cadinol 81.70 0.70 13 19.60 a-n-normetadol 64.20 0.51 14 21.65 isoaromadendreno epoxide 84.10 1.11 15 42.63 diisooctyl 1,2-benzenedicarbilate 92.30 1.81 16 47.22 13-docosenamide (z) 88.30 29.13 17 47.61 3,5-di-tert-butyl-4-hydroxyanisole 69.30 25.07 18 49.91 7-acetoxy-3-methoxy-2(3,4-dimethoxy penyl) -4-chromen4-one) 68.40 0.80 f5-2paa 1 19.62 1,9,5-cycloheptatriene, 6-methyl-1(6methyl) -1,3,5cycloeptatriene-il) 82.00 0.61 2 42.63 diisooctyl 1,2-benzenedicarboxylate 94.10 1.75 3 47.68 3,5-di-tert-butyl-4-hydroxyanisole 69.60 97.65 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f6-2paa 1 12.12 cariofillene 87.40 52.31 2 14.65 2,3,5,6,8a-hexahydro-4,7-dimethyl-1(1methyl ethyl) (1scis) or cadine-3,9-dienenaphthalene 82.40 10.54 3 16.34 espatulene 88.00 37.15 table 6. molecules found by cg-'ms in the methanol fractions of the leaves of 12paa specie (caryocar glabrum) f2-12 paa nº retention time, min molecules prob. % area 1 11.17 7,8-epoxylanstan-ol, 3-acetoxy 63.1 0.95 2 11.172 4,3-ethyl-5-octadecane 66.9 1.79 3 14.624 72.1 0.62 4 18.872 1,2,8-trimethyl-4-propenyl(e) naphthalene 80.9 0.70 5 19.64 1,1''bisphenyl, 2,2 ', 5,5'-tetramethyl 81.3 1.78 6 20.939 1,1'-dodecylidene bis (methyl) benzene 65.4 1.78 7 42.638 mono (2-ethyl hexyl) 1,1'benzenedicarboxylate 98.1 93.19 f3 12paa 1 14.6 2,4-bis (1,1-dimethyl-ethyl-phenol) 73.3 1.37 2 42.6 diisooctyl 1,2-benzene dicarboxylate 96.6 98.6 f4-12paa 1 14.61 3,5-bis (1,1-dimetyl ethyl)-phenol 78.9 2.10 2 43.63 diisooctyl 1,2-benzene dicarboxylate 96.5 97.0 f5-12paa 1 14.61 7,8-epoxylanostan-11-ol, 3 acetoxy 60.3 3.71 2 16.8 chlorotetracycline 62.2 3.62 3 42.6 diisoctyl 1,2-benzenedicarboxylate 95.7 92.59 f6-12paa 1 23.7 9 h-fluorene, 9-methylene 95.9 11.23 2 30.7 fluoranthene 95.7 33.14 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3 32.12 pyrene 93.2 24.65 4 41.5 benzantrene 90.3 6.48 5 42.63 diisoctyl 1,2-benzenedicarboxylate 94.2 24.47 table 7. molecules found by cg-'ms in the methanolic fractions of the leaves of the 14paa specie (tapirira guianensis) f1 -14paa nº retention time, min molecules prob. % area 1 14.02 decahydro-4a-methyl-1-methylene-7(1methylethylidene) -4 a-trans-naphthalene 80.7 6.7 2 14.81 2,4-bis (1,1-dimethylethyl) -phenol 76.2 11.19 3 19.65 naphthalene, 1,2,3-trimethyl-4-propanil 70.5 5.84 4 47.27 vitamin e 80 76.17 f2-14paa 1 10.93 copaene 81.2 12.41 2 13.83 2-isopropyl-4a, 8-dimethyl-1,2,3,4,4a, 5,6,7octahydronaphthalene 86.2 8.62 3 13.94 eudesna-4 (14), 11dieno 67.8 2.89 4 14.03 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7(1methylethyl enyl) [1r (1a, 7a, 8a, a)] naphthalene (synonimous 2valenceno) 96.8 33.67 5 14.73 a-panasinsene 89.3 42.42 f3-14 paa 1 11.58 2,4-bis (1,1-dimethylethyl) -phenol 69.2 2.944 2 14.83 α -patchulene 83.4 9.13 3 13.93 valenceno 88.6 27.87 4 14.03 a-panasinseno 88.6 39.596 5 14,72 diisooctylphthalate 95.0 20.407 f4 14paa 1 13.859 α -patchulene 74.2 2.011 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 14.058 (+) valencene 91.4 4.086 3 42.659 diisooctylphthalate 96 93.903 4. discussion test for antioxidant activity. based on the results presented in table 2, it can be stated that of the 31 species studied, 9.7% exceeded 60% inhibition, while 16.1% exceeded 45%. the families with better results, besides those mentioned, of inhibition were annonaceae, apocynaceae and a species of euforbiaceae, with inhibition greater than 40%. these results are within the expected, since researchers who worked with 25 plants from colombia, found similar or higher percentages of inhibition, and those who also consider that the euforbiáceaes have good antioxidant qualities (mosquera et al. 2007). according to these results, the three with the best activities were selected: virola sebifera (myristaceae). caryocar glabrum (caryocarceae) and tapirira guianensis (anacardiaceae), which present an inhibition percentage of 81.08%, 74.25%, and 79.41% respectively, at the concentration of 5.0 mg/ml and the ic50 of each of them is 1.5 mg/ml 2.2 mg/ml, and 2.8 mg/ml, respectively. phenols and total alkaloids. several authors agree that the high concentration of phenolic compounds in a plant species has high antioxidant activity, this correlation is given for wine, which at higher phenolic concentration improves antioxidant activity. this is the case for tea (camellia sinensis) (benzie & szeto 1999), from lime (tilia argéntea) (yildrim et al., 2000), among others. according to table 3, it can be observed that the concentration of phenolic compounds is high in the species virola sebifera 18580.87 g/100g followed by caryocar glabrum 15180.71 mg/100g and tapirira guianensis 11568.78 mg/100g. it is worth mentioning the very similar concentration of flavonoids and the high presence of anthocyanins, proven compounds with a high antioxidant effect. in the case of c. glabrum, researchers found molecules in the bark of this species, such as coumarins, (aladul et al., 2007), as well as (rodríguez et al., 2017), who found several anthocyanins in t. guianensis, such as quercitin, and derivatives thereof. it is observed that the concentration of alkaloids is present only in the species virola sebifera and tapira guianensis, but not in the caryocar glabrum; indicative that these substances do not play an important role in this species, as antioxidants. reducing its activity with greater certainty to the phenolic compounds present. on the other hand, in the other species virola sebifera and tapira guianensis, an appreciable concentration of these substances is observed, and according to (chávez et al., 1996), they indicate that many alkaloids of different types of structures have been shown to be powerful inhibitors of singlet oxygen. many of these compounds proved to be better inhibitors than the tertiary amine 1,4-diaza [2.2.2] bicycloctane (dabco). likewise, (ibarra et al., 2011) found a high antioxidant activity in the alkaloidal fractions of erytrina americana, and when isolating the molecule erisodin, found that it had an ic50 of 150 μg/ml. molecules identified by cg-ms the molecules of interest found in the methanolic fractions were a) v. sebifera: folic acid, 3,5-diterbutio4hydroxyanisole (phenolic), caryophyllene (bicyclic sesquiterpene) and spatulenol (alcoholic sesquiterpene); b) c. glabrum: 2,4-bis (1,1-dimethylethyl) -phenol, 1,1'-benzenedicarboxylate of mono (2-ethyl hexyl), 9 hfluorene, 9methylene, fluoranthene and pyrene (these last two, aromatic compounds) and c) t. guianensis: vitamin e, copaene (tricyclic sesquiterpene), patchulene and valencene both (sesquiterpenes). likewise, observing the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset compounds currently recognized as antioxidants, there is an anisole derivative in fractions f2, f4 and f5 of v. sebifera, such as 3,5-di-tert-butyl-4-hydroxyanisole in fraction f3, f4 c. glabrum, phenolic derivatives, such as 2,4-bis (1,1-dimethylethyl-phenol) and 3,5-bis (1,1-dimethyl-ethyl) -phenol and in the f1 of t. guianensis, the vitamin e. 5. conclusion according with the results, the species virola sebifera, cariocar glabrum and tapira guianensis, present excellent antioxidant activity and the chemical analysis showed several molecules of interest, for this activity. 6. acknowledgements to the national innovation program for competitiveness and productivity (innovate perú), of the ministry of production of peru; for financing this study. 7. references duke, j.; vasquez, r. (1994) amazonian ethnobotanical dictionary. crc press book taylor & francois group. 224 p. gobierno regional de loreto (2011). resolución directoral nº 003-2010-ggr/procrel-de. plan maestro del área de conservación regional “comunal tamshiyacu tahuayo” 2011-2015. belén. shoobridge d., manrique c., moran m.; carreón, g.; macahuachi, r., (2004). evaluación socioambiental de la zona del yavarí-yavarí-mirín y tamshiyacu-tahuayo. parks watch, strengthening parks to safeguard biodiversity. 99 p ibarra, e.; pacheco, m.; garcía, m. san miguel chávez, r., 2011. actividad antioxidante de alcaloides de erythrina americana miller. rev. fitotec. mex. 34 (4): 241 – 246. coronado m.; vega y león, s.; gutiérrez, r.; vázquez, m.; radilla, c. (2015). antioxidantes: perspectiva actual para la salud humana. rev chil nutr 42:2:206-212. sotero, v.; silva, l.; merino, c.; et al. (2011). evaluación de la actividad antioxidante de seis frutales amazónicos: anona, castaña, chope, huasaí, huito y uvilla. folia amazonica.20(1-2):53-58. valls, j.; lampreave, m.; nadal, m.; arola, l.; (2000) importancia de los compuestos fenólicos en la calidad de los vinos tintos de crianza. alimentación, 119-124. shamsa, f., h.; monsef, r., ghamooshi, verdian-rizi, m. (2008). spectrophotometric determination of total alkaloids in some iranian medicinal plants. thai j. pharm. sci. 32: 17-20. sotero, v.; suarez, p.; vela, j.e.; garcia de sotero, d.; fujii, y. (2016). allelochemicals of three amazon plants identified by gc-ms. international journal of engineering and applied sciences. 3(2): 1-3. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mosquera, o.; correa, y.; buitrago, d.: niño, j. (2007). antioxidant activity from colombian flora mem inst oswaldo cruz. 102(5): 631-634. benzie, i.f. and szeto, y.t. (1999). total antioxidant capacity of teas by the ferric reducing/ antioxidant power assay. j. agric. food chem. 47: 633-636. yildrim, a. mavi, a. oktay, m.; kara, a.; algur, o. and v. bilaloglu. (2000). comparison of antioxidant and antimicrobial activities of tilia (tilia argentea desf. ex dc), sage (salvia triloba l.), and black tea (camellia sinensis) extracts. j. agric. food chem. 48: 5030-50 alabdul magid, a.; voulquenne-nazabadioko, l.; moroy, g.; moretti, c. (2007). dihydroisocoumarin glucosides from stem bark of caryocar glabrum phytochemistry. 68: 2439-2443. rodríguez, a.m; guimarães, d.o; konno, t.u; tinoco, l.w.; barth, t.; aguiar, f.a.; lopes, n.p.; leal, i.c.; raimundo, j.m.; muzitano, m.f. (2017). phytochemical study of tapirira guianensis leaves guided by vasodilatory and antioxidant activities. molecules. 22: 304-319. chávez, r.; plaza, a.; lock, o. (1996). antioxidantes de origen vegetal. revista de química. puc-lima. 10(1): 71-101. mailto:topacademicjournals@gmail.com microsoft word 3.docx academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset diode laser absorption: a promising tool for anemia and polycythemia evaluation 1dr. ahmed khalid al-jaberi, 1dr. fatima hassan al-mansoori and 2dr. ali abbas alhassani 1university of wasit, college of medicine, iraq 2university of kufa, college of dentistry, iraq abstract: anemia and polycythemia are prevalent hematological disorders with a significant impact on the health of individuals residing in the mediterranean region and the middle east. this abstract provides an overview of the clinical associations, etiology, and consequences of these conditions. anemia is a condition characterized by a deficiency in red blood cells or hemoglobin, resulting in reduced oxygencarrying capacity of the blood. it is often indicative of underlying health issues such as chronic renal failure, endocrine disorders, joint diseases, gastrointestinal diseases, and liver diseases. deficiencies in essential nutrients like iron, vitamin b12, and folate can also lead to anemia. recognizing the diverse etiologies of anemia is crucial for effective diagnosis and management. conversely, polycythemia is a disorder characterized by an excessive production of red blood cells, which can impair oxygen transport and lead to various complications. chronic smokers, for instance, are at risk of carboxyhemoglobin formation, which reduces oxygen release from hemoglobin. additionally, polycythemia can result in renal hypoxia and autonomous erythropoietin biosynthesis, further exacerbating the condition. early identification and intervention are essential to mitigate the adverse effects of polycythemia. understanding the complex interplay between these hematological disorders and their associated comorbidities is crucial for healthcare practitioners in the mediterranean region and the middle east. timely diagnosis and appropriate management of anemia and polycythemia can substantially improve patient outcomes and overall quality of life. keywords: anemia, polycythemia, mediterranean region, middle east, hematological disorders. literature review obviously, anemia, as well as polycythemia, diseases are broadly distributed throughout parts of the mediterranean region and the middle east (1). they are always related with some functional disorders and diseases in human body. for example, anemia represent an indications of, chronic renal failure, endocrine disease, joint disease, gastrointestinal disease, liver disease and so on , as well as, in patients with iron, b12 and folate deficiency can cause anemia (2). on the other hand, polycythemia can lead to reducing o2 transport capacity – for example carboxyhemoglobin formation in chronic smokersreduced o2 release from hemoglobin, renal hypoxia, and autonomous erythropoietin biosynthesis (3). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset anemia is defined as decreased in the oxygen carrying capacity of the blood due to a decreased rbc's count or hb content or both below the normal range for edge and sex. this disease can lead to an increase in heart rate and pulse pressure as a result of decreasing in blood viscosity and low in peripheral resistance, decreasing in o2 supply to the tissue (hypoxia), vasodilatations from hypoxia and increasing in heart rate which lastly may lead to heart failure, and in hemolytic anemia there is increasing in formation of bilirobin which lead to jaundice in addition to clinical effects like headache blurring of vision and so on (1)(4). on the other hand, polycythemia or erythrocytes is refers to an increase in the rbc's mass. at hct above 50%, blood viscosity increases exponentially, and cardiac function and peripheral blood flow may be impaired. with a hct above 60%, blood flow may by so compromised as to lead to tissue hypoxia (1)(4). for that reason, it was needed to provide a new applicable technique to be personal use, easy, highly accuracy fast in getting result that will use for early detection. also, using laser light and exploiting some of its highly sensitive characteristics like change in light speed, and mono chromaticity, represent a helpful techniques for that purpose. recently, clinical health laboratories are depending on determination of packed cell volume (pcv) method for detecting the presence or absence of anemia or polycythemia, that measured by centrifugation. the accuracy of the results can be affected by using dirty or moist tubes, poor quality tube which are not of uniform bore, uneven seal, in complete packing due to insufficient force ( low rpm, short centrifuge arms), errors related with trapped plasma that will be increased in patients with polycythemia (5). noninvasive monitoring techniques were used to detect hb concentration in vitro, for example, plethysmography sensors, this method include using two detectors; one was electrical sensor designed to measure blood volume changes during the cardiac cycle and optical sensor for detection of dye concentration which is analogous to human hb. the quantities were discussed as a possible index of in vivo hemoglobin concentration (6). doshi and panditrao in 2013 described indirect method for hb concentration determination using finger chip, that consist of upper shell contain led with two different wavelengths (660 and 940nm)for detection of deoxygenated and oxygenated hemoglobin respectively, transimpedance amplifier-detectorwas installed in the lower shell of the finger clip. output signal voltage was measured also output waveform is observed on digital storage oscilloscope, the hb concentration was determined by putting the finger between the finger chip of different subjects with different ages (7). ahmed et. al. explained a direct method for measuring hb concentration for men and women, using three different lasers' wavelengths – depending on absorption spectrum of hemoglobinwith different output power, and optical fiber as a sensor for the quantity of transmitted light that passed through the blood sample, they alleged that blood hb concentration could be determined by plane polarized light (8), while the practical truth that had been sustained was the blood hemoglobin could not be able to rotate the incident plane polarized field. however, they demonstrate the result that had been get were depended mainly on absorbance measurements to determine any changes in hb concentration that absorb a certain wavelength of light. other articles like (9),(10)(11) were explained the same method of pulse oximetry (finger clip) in measuring hb concentration with the same principal of working. in this work, a new suggested biosensor design was used to determine either the patient had anemia or polycythemia, by comparison between tested or control blood samples mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of healthy persons with normal pcv, according to the blood group control. the blank of biosensor is distilled water that used by calibration with polarizer to make the reading power 26.99 µw as wo .the designation of biosensor used beer-lambert principle as following: wx = wo exp-αx where; wx is the power of light through the sample, wo is the power of incident light from source, x is the path length of laser light equal to 1cm of cuvette sample, α is the absorption coefficient of sample that it is different with different blood group and hb concentration. material and methods blood sample: five replicates of different blood sample were taken from (kut bank of blood) of different healthy persons, different blood groups, with convergent pcv values; in order to use as control. (al-karamma hospital) supported the project with 35 blood sample from patient of anemia, and 35 blood samples from patient with polycythemia, with same pcv for each group, and each sample were classified according to blood group. the control blood samples and tested blood samples were diluted with distilled water. the diluted factor was 1:90. the donor persons are of age between 1863 years old. biosensor setup: it consists of (figure 1): 1. diode laser: wavelength 650 nm, output power through blank of distilled water 26.99 µw. 2. polarizer: to calibrate the output power of laser beam. 3. cuvette contain blood sample. 4. photocell to convert optical signal in to electrical signal. 5. power meter. figure 1: biosensor arrangement results and discussion the results – appendixwere analyzed using spss program by comparing means between blood sample of normal pcv as a control, and blood sample of anemia and polycythemia. in general, according to beer-lambert law, the decreasing in hb concentration – anemialeads to increasing in transmittance of laser beam through blood sample, and subsequently, the readings seems higher than control. this mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset results as same as the results that reached by ahmed, et.al (8). while in case of polycythemia, the means of tested samples were seemed to be less than control; due to increasing absorption of high hb concentration. in case of anemia, the results show there were a significant increasing in transmitted light, between the control and tested sample of blood groups (o+, ab+, o+, and o-), while there were no significant difference in b+ samples. for polycythemia, the highly significant difference was seen in (a+, a-, ab-, and a-), significant difference in o+, and b+ show no difference with control. conclusion b+ blood groups test, showed no significant increasing or decreasing in biosensor readings for anemia and polycythemia respectively, that made a hypothesis there were a correlation between hb concentration and blood group, i.e that reading of blood group could interfere with increasing and decreasing of hb concentration for certain groups. references provan, d. (2003). abc clinical haematology. second edition. bmj books is an imprint of the bmj publishing group. london. isbn: 0 7279 16769. pp: 1-19. provan d.; singer, c. r. j.; baglin t.; lilleyman, j. (2004). oxford handbook of clinical haematology. second edition. oxford university press, inc., new york. united states. pp: 57-154. harald theml,m.d.; heinz diem,m.d.; torsten haferlach,m.d.(2004). color atlas of hematology practical microscopic and clinical diagnosis. 2nd revised edition. thieme stuttgart · new york. united states.pp: 9-25; 127-170. guyton, a.c; hall, j.e. (2006). text book of medical physiology. 11th ed. elsevier saunders, philaelphia, pennsylvania, usa, isbn 0-7216-0240-1. pp: 417429. klee, g.; d ̓onofrio g.; bull, b.s.; davis, b.h.; fujimoto, k.; houwen, b.; koepke, j.a.; lewis, s.m.; rowan, r.m.; tatsumi, n.; van assendelft, o.w.; van hove, l. (2000). recommended method for the determination of packed cell volume by centrifugation. world health org anization. pp: 1-8. phillip, p.j; hickey, m.; kyriacou, p.a. (2012). evaluation of electrical and optical plethysmography sensors for non invasive monitoring of hemoglobin concentration. sensors, 12, pp:1816-1826. doshi, r.; panditrao, a. (2013). non-invasive optical sensor for hemoglobin determination. international journal of engineering research and applications (ijera), vol. 3, issue 2, pp:559-562. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ahmed, s.s.; al-naimee, k.a.; hayat, a.h. (2013). optical fiber hemoglobin concentration sensor based laser polarization. international journal of application or innovation in engineering & management (ijaiem). volume 2, issue 4, pp.: 572-577. doshi, r.; panditrao, a.(2013). optical sensor system for hemoglobin measurement. international journal of computational engineering researc,vol(03), issue(7), pp: 41-45. kumar, r.; ranganathan, h.(2013). noninvasive sensor technology for total hemoglobin measurement in blood. journal of industrial and intelligent information, vol. (1), no. (4),pp:243-246. patil, s.h.g.; ramkumar, p.s.; prabbu, g.k; babu, a.n. (2014). methods and devices to determine hemoglobin non invasively: a review. international journal of scientific engineering and technology (issn : 22771581).volume no.3 issue no.7, pp : 934-937. appendix anemia data a+ b+ ab+ o+ o a+ control b+ control ab+ control o+ control o control facto r 23.7 7 21.5 5 21.9 24.6 20.3 1 19.45 23.17 19.72 19.75 17.53 26.99 24.1 2 16.7 24.9 8 26.1 2 25.3 3 18.68 22.16 18.11 19.03 17.5 24.8 22.3 3 23.6 3 24.4 4 26.4 18.59 21.9 17.62 17.89 17.13 25.2 5 26.0 3 22.9 4 24.9 1 27.6 5 17.32 20.82 17.4 17.33 16.78 25.2 2 25.5 23.7 5 24.9 2 26.5 3 17 19.52 15.08 17.15 16.22 25.2 4 25.9 3 24.9 25.0 2 25.3 8 22.2 4 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 25.4 6 23.5 3 25.3 24.7 7 polycythemia data a+ b+ o+ a ab o control a+ control b+ control o+ control a control ab control o fact or 21.5 6 22.3 3 19.5 7 19.7 3 22.6 22.9 7 19.45 23.17 19.75 17.32 19.53 17.53 26.9 9 22.8 2 22.3 5 23.2 1 19.2 5 21.4 4 21.4 5 18.68 22.16 19.03 15.77 19.92 17.5 22.6 22.8 9 23.2 2 18.6 7 22.3 7 21.7 5 18.59 21.9 17.89 15.58 18.61 17.13 22.9 6 22.5 22.7 6 19.0 3 21.9 8 21.5 3 17.32 20.82 17.33 14.25 18.31 16.78 22.1 3 23.0 5 23.7 5 19.8 3 20.6 6 22.7 6 17 19.52 17.15 12.65 17.88 16.22 22.9 7 22.1 21.7 9 21.4 9 21.9 3 paired samples test (anemia) paired differences t df sig. (2tailed) mean 95% confidence mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset std. deviation std. error mean interval of the difference lower upper pair 1 a+ control a+ 6.42400 1.65337 .73941 4.37107 8.47693 8.688 4 .001 pair 2 b+ control b+ .90800 4.78025 2.13779 5.02746 6.84346 .425 4 .693 pair 3 ab+ control ab+ 5.85400 2.37610 1.06262 2.90369 8.80431 5.509 4 .005 pair 4 o+ control o+ 6.76800 1.17189 .52408 5.31291 8.22309 12.914 4 .000 pair 5 o control o 8.21200 3.24956 1.45325 4.17714 12.24686 5.651 4 .005 paired samples test (polycythemia) paired differences t df sig. (2tailed) mean std. deviation std. error mean 95% confidence interval of the difference lower upper pair 1 a+ control a+ 4.20600 1.35519 .60606 2.52331 5.88869 6.940 4 .002 pair 2 b+ control b+ 1.11000 1.64656 .73636 -.93447 3.15447 1.507 4 .206 pair 3 o+ control o+ 4.27200 2.63195 1.17704 1.00400 7.54000 3.629 4 .022 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset pair 4 a control a 4.18800 1.88220 .84174 1.85094 6.52506 4.975 4 .008 pair 5 ab control ab 2.96000 .90308 .40387 1.83868 4.08132 7.329 4 .002 pair 6 o control o 5.06000 .98191 .43912 3.84080 6.27920 11.523 4 .000 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset dynamic interplay: investigating the effects of atmospheric circulation and rotation on jupiter's great red spot elmir rasul hasanov and leyla farida aliyeva department of mathematics, azerbaijan state pedagogical university abstract: the atmosphere of jupiter, with its unique chemical composition and complex dynamics, stands in stark contrast to earth's atmosphere. jupiter's atmosphere is characterized by the presence of trace impurities such as ch4, nh3, h2s, ph3, and c2h6 in minuscule quantities. moreover, the visible disk of jupiter exhibits intricate and dynamic features, including zonal circulation patterns and uneven latitudinal distribution of horizontal wind velocities within its atmosphere. notably, jupiter's atmosphere harbors a robust equatorial acceleration, encompassing latitudes ranging from -15 to +15, with distinct features at latitudes of -7 and +7, coexisting with a more sluggish flow at the equator. another intriguing aspect is the presence of a formidable jet stream at a latitude of 25, symmetrically positioned relative to the great red spot (grs) at a latitude of -20, a celestial phenomenon that has captivated observers for over 350 years. this study delves into various atmospheric phenomena on jupiter, including cyclones, anticyclones, turbulence, and the enigmatic great red spot, which has piqued the interest of numerous researchers. discussions regarding the nature of the great red spot persisted until 1979 when the voyager 1 spacecraft transmitted its first detailed images to earth, conclusively confirming that the great red spot is a long-lived atmospheric storm on jupiter. however, a significant revelation from prior research is that the size and proportions of the great red spot have experienced substantial reductions over the past century, spanning from 1880 to 2000, with ongoing shrinkage at a rate of 0.190. the primary drivers behind these changes involve the drift of the great red spot, variations in its rotational period with respect to jupiter's disk, as well as fluctuations in its axial rotation period. furthermore, longitudinal oscillations and the complex dynamics of the great red spot continue to present intriguing puzzles for researchers. this study also investigates the internal dynamics and structure of the great red spot, shedding light on the nature of its peripheral ring, its distinctive coloration, and its interactions with other oval formations within the jovian atmosphere. these intricate details provide valuable insights into the ever-evolving nature of this remarkable celestial feature. keywords: jupiter, atmosphere, great red spot, equatorial acceleration, zonal circulation, atmospheric dynamics. i. introduction chemical composition and structure of the atmosphere of jupiter significantly differ from the atmosphere of the earth group. content of other impurities ch4, nh3, h2s, ph3, c2h6 in the composition of the atmosphere of jupiter, is very small. besides, the visible disk of jupiter is a complex dynamic system with characteristic zonal circulation and non-uniform latitudinal distribution of horizontal velocities of individual atmospheric flows. the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset characteristic peculiarity of jupiter is the existence of powerful equatorial acceleration, which covering belt of latitudes from -15 to +15, also inside this at latitudes of -7 and +7, and a slower flow on the equator. another peculiarity is the existence of a no less powerful jet flow at the latitude of 25, which located symmetrically relative to the latitude of the great red spot (grs) ( = -20) (observed more than 350 years), which three earth located in the southern hemisphere, would freely fit into it and this is particularly interesting. phenomena of cyclones and anticyclones, turbulence, and the great red spot, as well as some problems of the jupiter, have been considered by many authors [1–9]. discussions on the nature of great red spot continued until 1979, till spacecraft "voyager 1" transmitted first detailed images to earth. these data proved the hypothesis on the great red spot that it is a big long-lived storm in the atmosphere of jupiter. however, in work [6], authors indicate that the size and proportions of the great red spot significantly decreased over the past 100 years, from 1880 to 2000, and decreasing at present with the velocity of 0.190. basic reasons of change of such size are drift of the great red spot, and other factors are variations of its rotation period with the jovian disk, as well as the variation of rotation period around its axis also longitudinal fluctuations, and the complex dynamics of great red spot, still open for researchers. moreover, an internal dynamic of structure, the nature of the peripheral ring, the color of the grs, and its collision with other oval formations, which give some factors of modifications to this phenomenal formation. maybe, it is one of the central focuses for understanding the essence of phenomena occurring in the great red spot. dynamics of other oval formations, the vortex energy source, and the relation with the great red spot, and many others, are problems awaiting solution. in parallel, grs drift velocity not fixed, but according to the materials obtained by hubble space telescope (hst), scientists confirmed previously planned 90-day longtime oscillations of the grs of jupiter. furthermore, previous observations show that the rotation period was 6 days, and from 2006 to 2012 (just during this period, when the size of the spot decreased quickly) and also its rotation period decreased to 4 days. this fact includes that one of the main issues is that the rotation period is between 4 and 6 days. considering the above-mentioned factors, we may declare our researches plan now, which is on the problems of the great red spot of the jupiter. therefore, firstly we need to analyze the following main questions: how the process of cyclones and anticyclones influence on the instability of the grs? how cyclones and anticyclones effect on rotation velocity of the system of jupiter? how cyclones and anticyclones, dispersion law of gravitational-gyroscopic, strong radio waves, and magneto-spherical field impact on the stability of the great red spot? how cyclones and anticyclones impact on the solid pole (cool process) and gas-liquid pole (hot process), on the hydrostatical equilibrium and gas motion on the atmosphere and liquid on the grs? how cyclones and anticyclones influence on temperature gradient vector and its direction, on the search of the heating procedure and energy balances? for that reason, let us clarify the first question since this is the main factor of the existence of the great red spot. ii. how the cyclones and anticyclones influence on rotation stability of the great red spot. in this situation, for processing the cyclones and anticyclones, more suitable for applying is the rossby models [following as in [6]). since, within shallow water theory, the equation describing the dispersion of waves on the planet rotating with the planet around the z-axis is clockwise. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset here, the equation describing this process expressed in the local cartesian coordinate system and has the form: ( 2 4 2 z k 2cz 2) 2kz y cz 2 0 where z is the projection of the rotation velocity of the system on rjupiter the local vertical; y is the projection of the rotation velocity of the system on the meridian; cz the adiabatic velocity of sound, rjupiter -radius of the planet jupiter; kz is the wavenumber along latitude; the k y -the taken along of the meridian. here, as a high-frequency solution is the dispersion law of gravitational-gyroscopic waves, and the low-frequency solution is the dispersion law of rossby waves (suitable solution): 2kz y r rjupiter(k2 4 2z /cz2) . moreover, if the so-called rossby model is performed, then the rotation of the system, significant effects on the dynamics and peculiarities of wave structures. consequently, with consideration of the scale of the structure in a plane, that is perpendicular to the local vertical. therefore, the motions in the wave are subsonic in any case; this is sufficient condition for the existence of the rossby regime, to keep rotation direction. considering the coriolis force and its inhomogeneity along the meridian, the long-wave perturbations at the lower latitudes are rossby waves (planetary waves), supporting or creating zonal (along the latitude) flows on the nonlinear stage. it is regularly alternating cyclonic and anti-cyclonic rossby vortices in the mid-latitudes. however, the speed rotor is parallel or anti-parallel to the vector of the local angular velocity of the system, respectively. hence, there is a strict analogy, to other characteristic examples of rossby cyclonic, and anticyclone vortices are so-called ―barges‖ in the jupiter atmosphere. therefore, there is the rossby auto solution of the great red spot of jupiter, which has the cariole’s force in cyclones is directed from the center of the vortex. moreover, decreasing occurs in it, and in anti-cyclones, conversely, the increase of gas density; anti-cyclones are more longlived than cyclones, which related to dispersion characteristics (note) due to increased density. the total angular momentum of the anticyclone is higher than of the cyclone, under all other equal conditions. therefore, it should be noted that the rossby vortices drift slowly; along with velocity on the parallel to the west, in this case, the conditions of the rossby regime are performed in level better and under larger size scale of the system. iii. the mathematical statement of a problem according to the complete system of equations describing the motion of gas in the atmosphere, without consideration of dissipative effects, the equation of motion could be written in the form (by the type of euler): vg t [vg vg ] g z k fv f , where, v is horizontal velocity, vg f k z .geostrophic component of velocityg, z –isobaric surface, f=2 sin and the rotation velocity of jupiter, along latitude, f is horizontal gravity force, -horizontal operator surface, t –time. in case if the cell is symmetrical, d g g dz then the zonal component equation might be expressed by: f fz, g . it should be dt f dx noted that, if we present magnetospheres field from the upper pole, which pressure is higher than the down pole, then hot temperature gradient vector directed up will impacts on the solar wind with turbulence, so mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset that the rotation drags the magnetic field into archimedean spiral form, as is shown in fig (a) below. it means that formula of law archimedean spiral could be written as r a i.e. the type of spiral after formulation might relate to the so -called parker’s spiral: r r0 (v/ )( 0), formulating from the turbulence rotation (figure (b)), directed to converse rotation of vertical axis z of the planet, which gradient vector of temperature directed up to down vertical. in order of pressure differences between upward in higher to downward lower transition temperature from hot pole to cool pole, consequently, the part of downward contain solid molecules without fluid and gas. consequently, the great red spot (figure (c)) contain the center circumference circulation of the cyclone with liquid and gas, which by quasi-laminar (figure (d)) liquid (gas) transiting to turbulence (figure (e)), dependences of reynolds number are very large and tends to infinity re (inertia forces) re 1,re in this case as usually the continuity equation is u v 0,at (viscoce foces) x x the same time x-momentum u u v u u du 1 .where u is the free stream velocity, x y dx y u uv y note that in turbulent flows mechanical energy is transformed into internal energy in two different ways: (a) in direct dissipation: transfer is due to the viscosity in laminar (for small viscosity term) where the winding angle is . ( tan ) 0 r r r v r r v v b b .upward pole of jupiter by parker’s spiral is mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (b) in turbulent dissipation: transfer is due to the turbulent fluctuations it seems to us the 68 per sent energy of jupiter may be transferred from the turbulence kinetic energy and others thermal searches. since the size of the earth is two diameters, a large red spot is an anticyclone in the atmosphere of jupiter, the long-term stability of which is due to the very fast rotation of jupiter around its axis (a day on jupiter is 10 earth hours). if there is a pressure drop, then it acting in opposite direction to thecoriolis force and growing with the meridian displacement of the flow, then the medium shows elasticity, and waves called the rossby waves, arise in it. their frequencies are very small less than one hundred thousandth of a hertz. because the coriolis force that excites them is proportional to the angular velocity of rotation, the view of jupiter exists without collapsing and would be preserved all time by its natural equilibrium. frankly speaking, for the jupiter issue the energy and magnetic field accepted the hypothesis in the following: the mechanical coupling between different parts of the planet the comparison is an advanced character only to friction. the electrical conductivity of most interior and lower atmosphere of jupiter is higher enough for the internal magnetic field of the planet contribution significantly on mechanically coupling, frictional coupling for transforms rotational energy irreversibly into heat, magnetic coupling transforms rotational energy reversibly into magnetic energy. in this case, the magnetic field will have a toroid type, which we describe in the parker spiral form for the initial impact on the atmosphere of jupiter. if we take into account that the ―wake‖ of the grs was at rest before the start of the clarification process, then this suggests a dynamic relationship between atmospheric flows around the grs and the ―life cycle‖ of seb, the behavior a long period of time.although the small red spot may appear small compared to the large scale of jupiter, however, this spot is actually the size of the earth, and the three times the diameter of the earth. both of these sunspots are giant hurricanes in jupiter's southern hemisphere, powered by warm air rising from their centers. the appearance of new red spots on jupiter in recent years and their dynamics suggest that global climate change is taking place on the planet. the structure, speed of rotation of its various parts, size and color largely depend on its interaction with a huge number of smaller vortices. the most striking feature of the thermal wind field of the grs core is related to the fact that evidence has been revealed for the existence of a weak counterclockwise rotation. atmospheric vortices on jupiter apparently exist for a more limited time, longer than cyclones and anticyclones on earth. iv. conclusion the result of our investigations consists of how the cyclones and anticyclones, and turbulence's stability effects on great red spot and to the rotation of jupiter. in this case, considered some factors noted by issues for the stability of rotation of jupiter with grs. for this reason, the necessary conditions of the long-time existence of the stability of grs on jupiter have been considered. by mathematical model describing the equation of motion for fluid–gas and stability conditions of grs, also radio-waves with magneto -spherical field, under spiral form turbulence with the wind, have been investigated. according to the work [2-9], as well as the above results, we can conclude as follows: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 3; may june 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset • in cyclones, the coriolis force is directed from the center of the vortex, therefore, a decrease is formed in it, and in anticyclones, on the contrary, an increase in the gas density; • anticyclones are much longer-lived than cyclones, what is associated with the increased density inside them and, therefore, other things being equal, the total angular momentum of the anticyclone turns out to be higher than that of the cyclone, so it is more difficult for it to disintegrate; • rossby vortices slowly drift along the parallel to the west with a speed not exceeding vdr vr where vr is the phase velocity of rossby waves; 20 journal of natural sciences, vol. 8(2), december 2020 • the conditions for the rossby regime are met the better, the larger the size system and its speed of rotation. therefore, its manifestations on the giant planets are much brighter than in terrestrial conditions. the authors declare no competing financial interests references beebe, reta. jupiter: the giant planet. — 2-еизд. — washington (dc): smithsonian institution press, 1996. — isbn 1-56098-685-9. jupiter: the planet, satellites, and magnetosphere / ред.:bagenal, f.; dowling, t. e.; mckinnon, w. b. cambridge: cambridge university press, 2004. — isbn 0-521-81808-7 johnwmcanally. jupiter and how to observe it. london springer, 2008.,isbn 1-85233750-8. david s. spiegel, nikkumadhusudhan. jupiter will become a hot jupiter: consequences of post-main-sequence stellar evolution on gas giant planets (англ.). astrophysics simon-miller a.a., gierasch p., et al. new observational results concerning jupiter’s great red spot.//icarus ,2002 v.158(1).p.249-266 rossby c. g. et al. // j. mar. res. 1939. vol. 2.p. 38. петвиашвили в.и. красное пятно юпитера и дрейфовыйсолитон в плазме //письма в жэтф. 1981. т. 32. вып. 11. с. 632-636. ingersoll a.p., dowling t.e., gierash p.j. et al. dynamics of jupiter’s atmosphere. //jupiter planet, satellites magnetosphere 2004. p. 105-128. антипов с.в., незлин м.в., снежкин е.н., трубников а.с. солитонроссби //письма в жэтф, 1981, т. 33, вып. 7, с. 368—372; т. 34, вып. 2, с, 83—86. mailto:topacademicjournals@gmail.com https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1560986859 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/0521818087 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1852337508 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1852337508 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1852337508 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1852337508 https://ru.wikipedia.org/wiki/%d0%a1%d0%bb%d1%83%d0%b6%d0%b5%d0%b1%d0%bd%d0%b0%d1%8f:%d0%98%d1%81%d1%82%d0%be%d1%87%d0%bd%d0%b8%d0%ba%d0%b8_%d0%ba%d0%bd%d0%b8%d0%b3/1852337508 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 https://arxiv.org/abs/1207.2770 academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a theoretical assessment of china’s rational choice decision making in african peacekeeping operations wei-lin chen department of diplomacy and international affairs ming chuan university taiwan abstract china is a major player in african peacekeeping operations (pkos) and makes decisions based on careful government options. the motivation to participate in pkos is not based on a fixed set of security or strategic interests but takes rational decision making into account to maximize utility. the literature points out that china is involved in pkos to promote international prestige, become a responsible world player or to gain operational experience but these goals are generally speaking also applicable to some other international objectives, for instance joint military exercises and technological exchanges. in view of this background, the study aims to examine china’s rational decision making in pkos focusing on the expectation that the leadership considers a list of options to maximize national or security interest, a reaction to an option is proposed, and with every option one course of action is chosen. peacekeeping intervention is analyzed in relation to the primary goal of promoting international peace and development with secondary contributions on specific goals in the peacekeeping environment. the study point out that peacekeeping is a means to exercise economic diplomacy, strengthen bilateral and multilateral relations, builds strategic partnerships and facilitates energy diplomacy. keywords: peacekeeping operations, rational choice decision making, bilateral and multilateral relations, economic diplomacy, strategic partnerships. introduction a major set of explanations for peacekeeping decision making are oriented around the motives and actions of the nation or government as unified, national actor. china’s independent foreign policy of peace stresses that fostering an international environment conducive to the peaceful development and co-existence of states is the baseline around which china’s relations with other countries are shaped. this statement also stands in relation to china’s engagement with african states to secure peace and stability and promote cooperation. in order to achieve this goal, the chinese leadership has to consider different options that can increase or decrease the value-maximization of this goal, make an assessment of the consequences attached to the goal, and decide on an alternative that suits the goal’s payoff function. what is important to note is that the promotion of peace and stability is viewed as the ultimate goal with peacekeeping a means to obtain this goal. peacekeeping is therefore not a goal in itself, but one of many tools china can use to add value to its african engagement. it is also not a definite conclusion that peacekeeping is the best choice after considering the different options and their consequences, and only that peacekeeping reinforces the decision of the chinese leadership to follow mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a certain course of direction. there are many intermediary or proximate goals that are not sought as ends in themselves, such as cultural and language exchanges, sport and academic interaction, and the establishment of small and private enterprises, as means to reach the goal of peaceful development and co-existence. peacekeeping has a good effect in many of these ‘subordinate’ goals to produce desired results. this is what allison & zelikow (1999: 15) refer to as focusing on an objective or cluster of objectives around which an account of valuemaximizing choice is constructed, with the effect to maximize the patterns of activities for each function. the application of china’s rational decision making in pkos takes this meansends relationship to into account. literature review the literature on china’s pkos is very extensive in nature and reflects not only on one aspect of participation, such as the desire for its troops to obtain peacekeeping or military experience in active areas of operations or to engage in security cooperation with contingents of other peacekeeping countries. research undertaken on china’s pkos first and foremost shows the intention to project a positive image of its political system abroad. through peacekeeping intervention in conflict areas, for that matter not only the african peacekeeping environment, but in all politically unstable and insecure regions where peacekeeping troops have a mandate fulfill the traditional role of peacekeepers and assist in wider peacekeeping activities, china’s actions are observed by a large group of interested people. academics, general chinawatchers, governments, nongovernmental organizations, lobbyists, local populations, civil groups in post-conflict societies or simply speaking, one and all, desires to see in what way china manages pkos and if chinese troops live up to official government policy and rhetoric of peaceful development and co-existence. the traditional/ classical school the rational actions of states are part of the classical school in decision making. this school perceives and acts on information from the situational context and makes decisions toward maximizing utility and predetermined goals. classical theories of decision making contend that rational choices explain possible alternatives made by nation-states as basic actors within the international system to maximize utility within a complete and perceived environment that includes their national political system as well as the international system as a whole, an internal environment, as well as an external environment(snyder, bruck & sapin, 2002: 58).within this classical school, some theorists diverge from the traditional political analyses that reify or personify nation-states as basic actors. instead of directing attention to metaphysical abstractions of the state, the government, or such broadly labeled institutions as ‘the executive,’ they narrow the subjects of their inquiry from larger collectivity to a smaller unit identifiable person responsible for making decisions, or to specific human decision makers who shape or establish government policies (lu, 2000: 184). as a step further, emphasis is placed on the study of motivation and characteristics of decision makers, for motives of states are not truly separable from the motives of individual decision makers who speak on behalf of states and rationalize their policy actions (snyder, et al, 2002: 58).scholars of the rational choice school differ over the emphasis they place on the significance of different decision making determinants. some focus on the study of the decision situation, which encompasses the total “external setting” and “internal setting” in which the choice must be made (brecher, 1972: 4). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the external setting includes the state’s geopolitical position within the global system and the regional balance of power, as well as the state’s relationship with relevant individual powers(sprout & sprout, 1956: 310).as for the internal setting, two crucial important variables are the state’s military and its economic capabilities, which set limits on what the government can do(lovett, 2006: 240).the internal setting also includes the domestic systematic environment and the structure of the political system in which decision makers must operate. in sum, these scholars believe the objective elements constitute the critical elements(lu, 2000: 184).in peacekeeping decision making, the influence of the pla and the domestic economic machinery are factors that narrow or expand the decision making power of china to attain its foreign policy objectives. other scholars assign perception a central place in foreign policy decision making. they regard the world as viewed subjectively by decision makers to be more important than objective reality. a distinction is therefore drawn between the ‘pshycomilieu’ and the ‘operational environment(lu, 2000: 185).’‘the operational environment affects the results or outcome of decisions directly,’ they argue, ‘but influences the choice among policy options, that is, the decisions themselves, only as it is filtered through the image of decision makers(rosenau, 1993).’ whereas the traditional stress the significance of the subjective ‘psychomilieu’ of china’s power elite in the formulation of the nation’s foreign policy, the realist/rational actor school focuses its attention on the objective ‘operational environment(whiting, 1960).’given the operational environment, the classical/rational actor school argues that china’s policy behaviour is hardly different from other countries. chinese decision making can be viewed in traditional western patterns of balance of power, national interests, and domestic economic, military, and systemic constraints(lu, 2000: 186).despite differences in focus on different key variables, the theoretical frameworks established under the classical school attempt to explain state behaviour in terms of a rational actor(bresslauer & tetlock, 1991).the classical school assumes that decision makers strive to be consistent, to make optimal choices in narrowly constrained, neatly defined situations, and to rank and maximize values by choosing the most efficient alternative(allison & zelikow, 1999: 15).this is to assume that decision makers clearly discern their objectives in view of the available options as well as the likely consequences of each alternative choice before making decisions(lovett, 2006: 240).in sum, the classical school stresses the rationality of decision making, a reflection perhaps of western intellectual’s faith in the essential rationality of human behavior inherited from the enlightment. the rational actor model this model draws on ‘realism,’ which regards states as rational unitary actors, and as the central units in international relations. it argues that state goals and national security are what determine policy choices. state actions are determined by international politics, and therefore domestic politics are not relevant(saikaly, 2009: 20).drawing on the assumptions of ‘rational choice,’ decisions are made from carefully considered government options, with cost and benefit analysis for each option to maximize utility(jervis, 1998). the inference in this model is that ‘if the nation performed an action of this sort, it must have had a goal of this type(allison & zelikow, 1999: 5).’however, this model does not consider that decisionmaking is not always rational, or that there are actors, other than the state, in foreign policy making. the core concepts of the ram mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset are: (1) the state has a list of goals deemed to be in the national interest, (2) in dealing with an international issue, a list of options is proposed, (3) as a reaction to an option a consequence is proposed, (4) with every option based on rational choice, one course of action is chosen, after cost and benefit analysis, in which the national interest is maximized (saikaly, 2009: 20).the assumptions of this model are summarized by concepts such as strategic problem, state goals, rational actor, valuemaximizing, and strategic interactions, which are operationalized with the following evidence: a) as evidence that a state wants to maximize goals, the expectation is that the operational environment provide opportunities and risks in attaining these goals and that choices to respond to these challenges create a cost-benefit assessment (bendor & hammond, 1992: 320-322).for china, potential examples may include failure to maintain mandates in peacekeeping areas, public criticism over the responsibility to protect (r2p), noninterventionism and respect for territorial integrity, traditional peacekeeping against wider peacekeeping, operational benefits, promoting a multilateral agenda, and protecting chinese interests abroad. b) as evidence of goals that the state has, observers would expect decision makers to articulate ends, such as the promotion of international image and prestige, promotion of economic interests and providing peaceful and stable environments(simon, 1985: 298).for china, this utility maximization may include exercising influence through economic diplomacy, strengthening bilateral and multilateral relations, promoting of culture and education, and gaining access to valuable african natural resources. c) as evidence of rationality, observers would expect the state to consider different options before making a choice, suggesting that no alternative is excluded because of evaluating the risks and opportunities(simon, 1985: 300).what is the best option for maximizing china’s objectives through peacekeeping? examples may include displaying power status and projecting an image of a responsible power, building strategic partnerships, such as economic free trade zones and acquiring markets for weapon sales, establishing security frameworks for protecting its interests abroad, and by assisting with security sector reform and training of african military personnel. d) as further evidence of rationality and of value maximizing, observers would expect discussions of the costs and benefits of each alternative, which ultimately determine the course of action to be taken(allison & zelikow, 1999: 26). china’s rational choice decisionmaking in pkos a. theoretical assessment the chinese leadership has not currently defined a definite strategy for pkos. the options they presently choose appear to be more of a collection of what will be effective under specific conditions, which relies on the influence they want to exert over post-conflict and other african states in economic and political arenas. while examining the overall preference of china to advance toward closer cooperation with african states, the importance they place on multilateralism, and the structural and functional role of the forum on chinaafrican cooperation (focac) and cooperation with other african regional bodies embody this cooperative framework, and strengthens security partnerships through military cooperation. peacekeeping is also integrated into this african strategy and is viewed as a part of the original preference. peacekeeping does not operate in isolation from china’s african strategy, since it contributes to specifying the optimal choice of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset leaders in an appropriate end-means calculation. chinese officials repeatedly state that none of their african ventures should be seen as means to an end, or in the language of power politics as wielding influence. however, without the presence of so many of chinese troops on the continent and the negative or positive images they portray, it is hardly unthinkable that peacekeeping is not a means to an end. peacekeeping is instrumental for china to reach their objectives and that the post-conflict societies in which they are involved holds particular significance for implementing foreign policy, which can have successful results. getting the proverbial “last soldier over the top of the hill to win the battle” is a reflection of the scope and intensity with which china views peacekeeping to maximize utility to the interest of international security goals. in addition, the use of chinese peacekeeping troops to assist in tasks beyond the scope of their assigned mission mandates indicates that the means of repairing infrastructure contributes to enhancing the objective of closer government cooperation and with the parties to the peace settlement. the certainty with which the means and ends are related and how closely the actual consequences of behavior match the consequences that are desired all depend on an understanding of the decision making process (russett, starr &kinsella, 2010: 164). rational decision makers resolve the conflicts they face in multi-attribute, that of subjective utility, and simply trading off to find the best outcome (gross stein, 2008: 102).considering the uncertainty of the environment and the perception of threat, chinese decision makers selfconsciously consider the values and goals affected by the peacekeeping environment and explain their interrelationships. gross stein, (2008: 102) states that after taking the anticipated consequences of actions into account, decisions are skilfully implemented and reviewed periodically to provide valuable feedback. in measuring the cost-benefit ration, the determination of china is to accept the risks the environment offers and increase its regional profile than to be outside the system and weaken its position (he, 2007). in applying the rational choice model to china’spkos, the assumption is that the decision making process should be logical and orderly, arriving at an expected or unintended outcome. the preferences of decisionmakers should be ranked, at least intuitively, in such a way that if i prefer a to b, and b to c, then i prefer a to c (gross stein, 2008: 103).in practical terms it means that if china prefers peacekeeping to conflict and conflict to economic diplomacy, then china should prefer peacekeeping to economic diplomacy. violating this this requirement of ‘transitive’ preferences, for example, if china prefers c to a, or economic diplomacy to peacekeeping, then china is ruled out as a rational decision-maker. as part of the process of making informed choices, china should be good at collecting and evaluating information on african pkos in a continuous and consistent manner. this will help to make choices based on responses that contain significant evidence. media reporting on african pkos feeds the chinese state propaganda machine with new information on an almost daily basis. information not previously accessed can be significant or diagnostic in that it presents evidence to the government in considering the likelihood of some of the consequences the government is considering (gross stein, 2008: 103).for instance, the consideration that peacekeeping could act as means toward economic ends, initially was not in the minds of the decision-makers, and subsequently is regarded as new information. it was diagnostic, insofar, african states signaled that they would be willing to establish a forum on china-african cooperation (focac), using the good intentions of chinese pkos as basis for this relationship. the minimal, commonsensical requirements of rationality in foreign policy mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset decision-making expect that policy makers can learn from history, that they can draw some propositions from the past and apply these propositions in an appropriate way to the future as they weight the likely consequences of the options that they face ((bendor & hammond, 1992: 325). the chinese leadership has a vast historical tradition of making strategic choices in warfare and security matters that they also can apply in peacekeeping decision-making. the question is if the chinese leadership approximates common sense of a rational decision-maker by making logical, discriminating while open to new evidence, coherent and consistent choices. are they open to arguments and evidence and think about the likely consequences of options, such as, sending more troops to post-conflict societies to increase outcomes or sending fewer troops to post-conflict societies to decrease outcomes. an alternative more demanding model of rational choice demands far more from decisionmakers. borrowing heavily from micro-economics, they expect decision makers to generate subjective probability estimates of the consequences of the options that they consider, to update these estimates as they consider new evidence, and to maximize their subjective expected utility (russett et al, 2010: 164).what options are available to achieve the greatest possible outcomes and what probability estimates are taken into consideration when choosing the best options? for example, is the option based on making troops more visible for the sake of showing goodwill, harmonious intentions and co-existence with other nations or are there ulterior motives involved based on gaining economic leverage, political influence and security cooperation with african states? chinese peacekeeping decision-making, indeed, rests upon a lot of options as the evidence points out and is not a one-track goal the leaders have in mind. theories of rational choice in foreign policy treat both initial preferences and expectations as given and exogenous (clarke, 1989: 30).models of rational choice identify the strategy that leaders should choose, given their preferences and expectations and assume that people are ‘instrumentally rational’ in the process of choosing. b. combining theory and practice the next section illustrates rational choice decision making in respect of china’s economic, energy and strategic goals. the peacekeeping options that strengthen these goals are elaborated in the second instance. the consequences of these options toward the goals are then examined and lastly, the option is chosen that adds value to each goal. china’s choice is essentially explained by demonstrating the best option to maximize the peacekeeping utility function. a) goals securing a peaceful and stable environment is viewed as the national or ultimate goal in the three mission countries. this goal is ordered to be the highest in the payoff, or the utility of preference function, which represents the desirability or utility of alternative sets of consequences (vickers, 1995: 54). in effect goals of national propriety are rank ordered from the highest to lowest in value maximization. for example, goals that serve the direct national interest may include gaining a strategic foothold in western africa, countering the western sphere of influence, giving aid and assistance, promoting international prestige, becoming a responsible player in world politics, and establishing trade partnerships and opportunities for investment. these goals are all relevant in china’s engagement with african states and serving the country’s interests. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset b) options the options pertain to the way in which peacekeeping strengthens the goals of china. the argument is that peacekeeping is viewed as a tool that combines the different options into securing a peaceful and stable environment as the national goal. to gain a strategic foothold in western africa, an increasing number of diplomats visit the selected countries to negotiate strategic and security issues, which points to the capacity of cooperating with these states. pertaining to the objective of strengthening trade and economic relations, china can promote economic dialogue between sino-african business actors, and encourage small and medium sized enterprises (smes) to begin operating and promote two-way flow of trade. although many of these entrepreneurs come to africa by their own accord and do not receive any government assistance, they are still citizens of china and act as subjects of the chinese state. what is significant from this option is that peacekeeping troops support these vendors in the sectors where they are stationed. informal interaction between the shop owners and the soldiers constitute a positive relationship that adds value to the presence of the troops in the country and maximize the utility function of peacekeeping, when they invest in the agricultural sector to increase food production, and become involved in the mining industries for the extraction of minerals that can satisfy china’s demand for these resources. moreover, the actions peacekeeping troops perform increase china’s status in these countries and contribute to goal-seeking ambitions. examples of such alternatives varies from, a) providing medical assistance to local populations in the sectors where the troops are stationed, b) providing transportation services between towns and villages for citizens to commute safely from one destination to another where such services did not previously exist, or was in a very bad state of affairs and c) building or repairing infrastructure, such as, roads and bridges, which increase the economic efficiency of the host country, accelerates economic development and from the chinese side, facilitates faster access to resources and transportation to ports for shipments to china. c) consequences there is an attached a set of consequences or outcomes of choice for each alternative that will ensure if that particular alternative is chosen (allison & zelikow, 1999: 18). such ventures hold promising results for strengthening and maintaining economic cooperation. it is assumed that peacekeeping is in direct relationship to the achievement of economic goals, oil diplomacy and strategic partnerships. the image peacekeepers portray, the praise and recommendations they receive from the host governments and the perceptions local populations have toward them, facilitate cooperation on economic grounds. acts such as these reinforce or weaken the decisions of the leadership to send troops. the leadership can either accept the invitation by the united nations security council (unsc) to contribute to mission areas, or abstain from intervention because peacekeeping does not promote the interests of china. the actions of the peacekeepers in the mission areas provide straightforward results. in this instance, they provide services that are observable and measurable in terms of the work they are doing. their actions are also viewed through the lenses of the chinese media, the central leadership, and observers on the ground from other peacekeeping contingents, local populations and civic-society groups. decision makers can now select the option whose consequences rank highest in the decision maker’s payoff function (axelrod, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1984).considering this analytical scheme, which encompasses the goals, options, and consequences, it is a fair judgment to make that peacekeeping adds value to the goal-seeking ambitions of china in post-conflict societies. providing for basic human needs in the lives of citizens and doing tasks beyond the necessary requirements is a consequence that is commended by one and all. in providing medical services, china displays its willingness to assist local populations and members of other peacekeeping contingents who need medical attention. this option showcases the medical capabilities of china to the outside world. organizing transportation services involves expediting and shifting goods from one destination to another, and also portrays willingness to move its own personnel around for early peacekeeping efforts of security sector reform (ssr). without logistical support and forms of transportation for the sectors under its command, communication with own forces and citizens might break down. china is filling a gap in services that are not provided by other peacekeeping contingents, which indicates that china is willing to shoulder more responsibilities, expand its scope of pkos, and satisfy the strategic and business goals of the chinese leadership. repairing infrastructure at a very basic level is an option that has good resonance on the perspectives of local populations in the three countries toward chinese peacekeeping troops. this kind of option, therefore, is viewed in favourable light and signals an intention of commitment by china to not only keep warring parties apart, monitor ceasefires and participate in sector patrols, but also to take part in nontraditional peacekeeping activities. d) choosing and option rational choice is value-maximizing, which means that the rational agent has to select the option with potential consequences that rank highest in terms of reaching goals and objectives (allison & zelikow, 1999: 24). considering the options and their consequences available to the chinese leadership, the question is which option has the highest payoff function. in examining the options it is evident that economic diplomacy is an effective tool to promote its african diplomacy. the function of peacekeeping in this relationship is to give effect to economic diplomacy through trade, the signing of business partnerships, trade and investments. peacekeepers, as actors of the chinese state, also shape negotiations that may occur on levels of high politics. for example, peacekeeping intervention in liberia serve the means to secure access to natural resources and gaining a strategic advantage over adversaries, which is an element of high politics. in essence, high and low politics diplomacy is essential to national power and well-being and peacekeeping intervention maximizes the value of interests. providing medical assistance, transportation and building or repairing infrastructure are positive goal-seeking actions. these actions demarcate the boundaries between traditional peacekeeping and early peace building activities. these actions also indicate that china is not content with only playing the pacifier role that most of the other peacekeeping countries perform, but is also prepared to move on to constructive engagement and dynamic interaction. as a significant contributor to african pkos, the leadership has to make decisions that elevate the status of china in relation to the functions the troops perform. critic on the rational actor model the rational actor model is also subjected to criticism. the model tends to neglect a range of political variables, of which michael clarke includes: ‘political decisions, non-political decisions, bureaucratic procedures, continuations of previous policy, and sheer accident (clarke, 1989: 31).’ there are factors in the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset peacekeeping decision-making process complicating the ordering of tasks, roles and policy and they are simply dismissed or ignored. for example, political factors that might play a role in the operational environment as essential to influence the objectives of the central leadership are not accounted for. these factors, then are exogenous to the choices of china and has minimal or limited impact on utility maximization. since the beginning of the twenty-first century, chinese government officials have recognized that challenges can have detrimental or beneficial effects on china’s international status and performance. as richard snyder observes, a crisis can lead to closer integration of the foreign policy-making group, the clarification of values, and adaptive innovation; or it can produce behavior that threatens the survival of the nation(hermann, 1963: 62).even though african peacekeeping per se is not viewed in terms of a crisis for china, because it does not endanger national interests on the homeland or threaten the direct survival of the chinese nation-state it provides opportunities for integrating decision-making procedures of all the relevant actors, and leads to conditional changes in the behavior of the central leadership. conclusion rational action is most effectively viewed as an analytical tool that pragmatically explains china’s peacekeeping decision making. the actions china’s takes in the peacekeeping environment focus on valuemaximizing the means for achieving objectives, and as this paper indicates, the principle category in which china’s realizes its objectives is security and interests. gaining access to natural resources and protecting the interests that are derived from these industries is viewed as the main objective. rational action assumes that actors are individualistic in nature, and in this paper focused on china’s behavior of china’s as a single unit. the implementation of china’s rational choices served the purpose of exemplifying the behavior of the decision makers. the positive effects of peacekeeping on the perceptions of post-conflict societies referred to the absolute and unconditional trust and faith in the actions of china, which are considered as taken for granted. the cooperative agreements reached between african leaders and china, which includes countries where peacekeepers are stationed, strengthened this position. although chinese documents state in detail that promoting a peaceful society and co-existence with other nations are the core foundations of its independent foreign policy of peace, and that participation in pkos is a means to reach this goal, the evidence suggests that it is tacitly understood by citizens living in these conflict areas and merely rhetoric to gain access to resources, increase its bargaining power and exert other forms of influence. in addition, the choice of whether to treat the preferences of china as given is important because it strengthens the assumption that the decision makers make empirical claims about the peacekeeping environment and what they want is constant within the context of peacekeeping actions. a consequence for china’s in securing a safe environment for conducting business and protecting interests is to cooperate with other actors on a consistent basis. if this does not happen, policies with regard to peacekeeping implementation may not have the desired effect, or may understate the potential for political change. in reality, it is not clear if there is a boundary between the actions and interests of china. this could be investigated further in a separate study, especially since there has been a lack of clarity regarding whether china’s peacekeeping decision making has been viewed as a result of the fixed preference assumption or as natural action to protect its interests.the core of rational action is individual choice, which crucially depends on the beliefs of the decision makers and the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset way in which desires and beliefs culminate in the taking of actions. rational action further highlights the goalseeking ambitions of china and in this paper it is a fair claim to make that peacekeeping adds a foreign policy dimension to china’s total african strategy. peacekeeping is also a political instrument in the hands of decision makers that, although indirectly, acts as a driving force to gain access to africa’s strategic marketplace through peaceful intentions and shows of goodwill. analyzing china’s actions advanced a strong hypothesis about a course of action. what is further important is that china has to make calculations about appropriate options, express them as pros and cons and choose alternatives that best advance its interests. supplementing this logical order of events is china’s readiness or reluctance to take risks in this environment. references axelrod, r. 1984. the evolution of cooperation.new york: basic books. bendor, j. and hammond, t.h. 1992, “rethinking allison’s models,” american political science review, 86(2): 301-322. brecher, m. 1972. the foreign policy system of israel: setting, images, process. new haven: connecticut, yale university press. bresslauer, g.e. and tetlock, p.e. eds. 1991.learning in u.s. and soviet foreign policy. boulder colorado: westviev press. clarke, m. 1989, “the foreign policy system: a framework for analysis,” in clarke, m and white, b eds., understanding foreign policy: the foreign policy systems approach. cheltenham: edward elgar publishers. he, y. 2007.china’s changing policy on un peacekeeping operations. sweden: institute for security and development policy press. hermann, c.f. 1963, “some consequences of crisis which limit the viability of organizations,” administrative science quarterly (spring 1963): 343-58. jacobsen, l. and knox, d. 2010. new foreign policy actors in china. stockholm: stockholm international peace research institute press. jervis, r. 1998, “realism in the study of world politics,” international organization, 52(4): 971-91. lovett, f. 2006, “rational choice theory and explanation,” rationality and society, 18(2): 237-272. ning. l. 2000. the dynamics of foreign-policy decision making in china. oxford: westview press. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset rosenau, j. 1993, “china in a bifurcated world: competing theoretical perspectives,” in chinese foreign policy: theory and practice, eds., robinson, t. and shambaugh, d. new york: oxford university press. russett, b. starr, h. and kinsella, d. 2010. world politics: the menu for choice, ninth edition. wadsworth: cengage learning. saikaly, r. 2009. decision making in u.s. foreign policy: applying kingdon’s multiple streams model to the 2003 iraq crisis. ohio. kent state university press. simon, h. 1985, “human nature in politics: the dialogue of psychology with political science,” american political science review, 79: 293-304. snyder, r.c. bruck, h.w. and sapin, b. 2002.foreign policy decision making, second edition. new york: palgrave macmillan. sprout, h. and sprout, m. 1956, “environmental factors in the study of international politics,” journal of conflict resolution, 1 (1): 309-328. stein, g.c. 2008, “foreign policy decision-making: rational, psychological, and neurological models”, in smith, s. hadfield, a. and dunne, t. eds., foreign policy: theories, actors, cases. oxford: oxford university press. vickers, g. 1995. the art of judgement: a study of policy making. thousand oaks: sage publications. whiting, a.s. 1960.china crosses the yalu: the decision to enter the korean war. stanford: stanford university press. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset motivation and interest among btte student teachers: a comprehensive study maria santos dela cruz cie, tup manila, philippines abstract: motivating students in the classroom is a complex task that depends on various factors, including the teacher's ability to inspire and challenge them. this study focuses on understanding the motivation and interest levels of students in the bachelor of technical teacher education (btte) program. student motivation is influenced by their initial enthusiasm, but it can also be shaped by the classroom environment and teaching methods. factors such as perceived usefulness of the subject, the desire to achieve, self-confidence, and persistence all play a role in student motivation. this research aims to examine these factors and their impact on student motivation and interest. by gaining insights into what motivates students, educators can tailor their teaching strategies to better engage and inspire their students. keywords: student motivation, classroom environment, teaching methods, perceived usefulness, student interest introduction some students are naturally enthusiastic about learning but many expect their professor to inspire, challenge and stimulate them. effective learning in the classroom depends on the teaching ability to maintain the interest that brought students to the course in bachelor of technical teacher education(btte), i the first place whatever level of motivation student bring to the classroom will be transformed for better or worse, by what happens in that classroom. unfortunately, there is no single magical formula in motivating students. many factors affect student’s motivation for them to work and learn, their interest in the subject matter, perception of its usefulness, general desire to achieve, self confidence and self esteem as well as patience and persistence. and of course, not all students are motivated by the approval of others; some by overcoming challenges. it is in the premise that their study shall be undertaken to determine the motivation and interest of the respondents. this study aim to determine the relationship of motivation and interest of btte students to their course in the college of industrial education, tup manila during the first semester, school year 2013-2014. specifically the study sought answer to the following questions 1. what is the profile of the respondents in terms of: a. age b. sex 2. what is the perception of the respondents with btte to their course? 3. what is the level of motivation of the respondents to their course? mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. is there significant relationships exist between the motivation and interest of btte student teachers are their course? the study hypothesized that there is no relationship exist between the motivation and interest of the btte student teachers and their course. review of related literature some students have been conducted related to motivation and interest all there was conducted towards the b growth and development of the student in school that will prepare them for the future. marsane (2003) stressed that what and how much is learned is influenced by the learner’s motivation. motivation to learn, in turn is influenced by the individual’s emotional states, beliefs, interest and goals and habits of thinking. the learners creativity, higher order thinking, and natural curiosity all contribute to motivation to learn. intrinsic motivation is stimulated by tasks of optional novelty and difficulty, relevant to personal interests, and providing for personal choice and control. mc combs (2001) identified that acquisition of complex knowledge and skills requires extended learner effort and guided practice. without learner’s motivation to learn, the willingness to exert this effort, is unlikely without coercion. educators need to be concerned with facilitating motivation by strategies that enhance learner effort and commitment to learning and to achieving high standards of comprehension and understanding. chavez (2012) pointed on his study that interest is the immeasurable quality that is seen, perceived and read by the people around us. it expresses actions, questions and facial expression; it is the basis of attention, the inner driving face of the person to pursue his curiosity. interest and attitude are used together to denote the individual’s towards himself, his environment like associates, teachers and elders or to the object or situation. there are people who show interest by watching an instruction or supervisor on the job with such an intensity that they appear mesmerized (http:www.eurojournals.com/ersr_26_3_16.pdf). interest plays an important role in the learning process, determining in past what we choose to learn and how well we learn it. interest affects attention, goal setting and learning strategies in ways that make it a particularly relevant for improving educational practice) lising 2004). in the study cabrella as cited by chavez (2012) one of the primary function of education is to develop motives and interest that will be lifelong in their effects. education should be develop needs and desires that the individual will constantly try to satisfy. methodology this study utilized the descriptive-correlation research design and obtains the profile of the respondents. the respondents were the bachelor of technical teacher education (btte) student teacher enrolled during the first semester of school year 2013-2014. this study used questionnaires in gathering the necessary data from the variables to be investigated. the data were treated statistically using frequency count, average mean and the pearson product moment of correlation. result and discussion profile of the respondents table 1: respondents profile as to age and sex variable frequency percentage sex female 37 48.1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset male 40 51.9 total: 77 100.00 age 19 2 2.6 20 14 18.2 21 28 36.4 22 2 2.6 23 9 11.7 24 9 11.7 25 5 6.5 26 2 2.6 27 2 2.6 29 1 1.3 30 1 1.3 31 1 1.3 36 1 1.3 total: 77 100.00 table 1 shows the profile of the respondents in this study. it includes their age and sex. sex: there are more male respondents (40 or 51.9%) as compared to female (37 or 48.1%) out of 77 age: the modal age range id from 21 to 24 years old comparing 48 out of 77 table 2: perception of the respondents to their course perception mean verbal interpretation 1 can i cope up with this course? 4.29 often 2 am i fit in this course? 4.21 often 3 will i be happy working here? 4.23 often 4 will this course imply discrimination? 3.49 sometimes 5 will i be impressed in this course? 4.19 often 6 will i be comfortable with my classmates? 4.27 often 7 will i be interested with the lessons and activities? 4.43 often 8 will the teachers be approachable? 3.99 sometimes 9 are the teachers efficient in theories and application? 3.97 sometimes 10 are the teachers strict? 4.09 often overall mean 4.11 agree legend: scale verbal description mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5 always 4 often 3 sometimes 2 rarely 1 never as shown in table 2 the data which revealed data perceived that they can cope up with their course is often (mean=29), while their course imply discrimination got the lowest mean (mean=3.97) interpreted as sometimes. the overall mean is 4.11 interpreted as agree. this means that the btte graduating students agree that they have good perception to their course. table 3: level of motivation of the respondents to their course motivation mean verbal interpretation 1 motivated in achieving related activities in field of specialization 4.08 agree 2 have an opportunity to perform challenging tasks in competitive situation 4.04 agree 3 develops confidence to solve problems in your major field of specialization 3.87 uncertain 4 interested in the learning task especially in your major 3.90 uncertain 5 have the ability to solve problems related to the fields 3.99 uncertain 6 accepts challenging task in major subjects 3.66 uncertain 7 active in searching for content information in major field 4.01 agree 8 feels happy when reports have done 4.27 agree 9 interested to perform activities to receive high grades 4.13 agree 10 interested to explore new things in major field 4.01 agree overall mean 3.99 uncertain scale verbal description 5 strongly agree (very high) 4 agree (high) 3 uncertain (moderate) 2 disagree (low) 1 strongly disagree (very low) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 3 presents the data on the level of motivation of the respondents to their course. the highest mean is (mean= 4.27) interpreted as agree and the lowest mean is (mean= 3.66) interpreted as uncertain. the overall mean is 3.99 interpreted as uncertain. they have good motivation in choosing their course. summary, conclusions and recommendation guided by the statement of the problem, the research study determined the level of interest and motivation of the btte graduating students to their course and the relationship of motivation and interest of the respondents to their course. on the respondents of the study the respondents of the study were the seventy seven btte graduating students, 40 are male and 37 are female their modal age range is from 21 to 24 years old comprising 48 out of 77. perception of the respondents to their course has an overall of 4.11 interpreted as agree, while the level of motivation of the respondents has an overall mean of 3.99 interpreted as uncertain. motivation and interest of the btte student teachers to their course is significant at 0.01 level of significance (two-tailed). based on the above findings the hypothesis stating that there is no relationship exist between the motivation and interest of the btte graduating student teachers to their course is rejected. the findings of the study call for this recommendation. provision on the implementation of orientation program for the incoming btte students to guide them on the program, so as to motivate there students to their course. references cashin, w. e “motivating students” idea paper no. 1 manhattan: center for faculty evaluation and development in higher education, kansas state university, 2000. dwya, letaua. (2003). motivation and schooling, review of educational research, 64,287-309. forsyth, d. r. and mcmillan. “practical proposal for motivating students” in r.j> merges and m.d. svinicki (eds) (2001). mcmillan, j. hands forsyth, d.r. “what theories of motivation say about why learners learn”(2000). mailto:topacademicjournals@gmail.com 060903-fa1701-academic journal of engineering and technology science.docx academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset aesthetics in sport technology: the case of table tennis cleaning machines li, xin-yu north china electric power university (beijing), beijing, china abstract: table tennis equipment, an essential component of the sport, often suffers from damage and staining, resulting from prolonged use and improper handling. to address these challenges and enhance the durability of table tennis equipment, a novel solution has emerged: the table tennis recovery cleaning all-in-one machine device. this innovative device, illustrated in figure 1 and figure 2, is specifically engineered to restore and clean table tennis balls and surfaces, ensuring their prolonged lifespan. incorporating cutting-edge technology, it offers a cost-effective and efficient solution for table tennis enthusiasts. the key feature of the table tennis recovery cleaning all-in-one machine device is its ball recovery system. this system efficiently gathers and restores stray balls, minimizing the need for frequent replacements and preserving ball quality for extended gameplay periods. furthermore, the device incorporates a cleaning mechanism that effectively eliminates stains and dirt from the surface of table tennis balls. through the use of gentle yet potent cleaning agents, it not only enhances the visual appeal of the balls but also improves their performance. the device's adaptability is a notable asset, as it is equipped with adjustable settings to cater to diverse cleaning requirements. users can customize the intensity and duration of the cleaning process, ensuring that lightly soiled and heavily stained table tennis balls receive the appropriate treatment. this versatility empowers players to restore their equipment and optimize their playing experience. additionally, the table tennis recovery cleaning all-in-one machine device boasts user-friendliness and convenience. it features an intuitive control panel and a compact design, rendering it suitable for personal use at home or within training facilities. safety features have also been integrated to prevent accidents and instill confidence in users. keywords: table tennis equipment, cleaning device, ball recovery system, equipment durability, sport technology 1. introduction table tennis plays a critical role in the game, but it is prone to damage and staining due to improper use and extended playing time. to address these issues and improve the durability of table tennis equipment, a new solution has emerged: the table tennis recovery cleaning all-in-one machine device, as shown in figure 1 and figure 2. this innovative device is designed to restore and clean table tennis balls and surfaces, ensuring their longevity. it incorporates advanced technology to provide a cost-effective and efficient solution for table tennis enthusiasts. the primary feature of the table tennis recovery cleaning[1] all-in-one machine device is its ball recovery system. this system collects and restores stray balls, reducing the need for constant replacements and preserving the quality of the balls for longer periods of play. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in addition, the device includes a cleaning mechanism that effectively removes stains and dirt from the surface of table tennis balls. by using gentle but powerful cleaning agents, it not only improves the appearance of the balls but also enhances their performance. the machine device is equipped with adjustable settings to cater to different cleaning requirements. users can customize the intensity and duration of the cleaning process, ensuring that both lightly soiled and heavily stained table tennis balls receive the appropriate treatment. this versatility allows players to restore their equipment and optimize their playing experience. furthermore, the table tennis recovery cleaning all-in-one machine device is user-friendly and convenient. it has an intuitive control panel and a compact design, making it suitable for personal use at home or in training facilities. safety features are also incorporated to prevent accidents and provide peace of mind to users. in summary, the table tennis recovery cleaning all-in-one machine device is a significant advancement in maintaining table tennis equipment. by effectively restoring dented and stained balls, it enhances their durability and preserves their performance. this innovative solution offers convenience and cost-effectiveness, enabling players to consistently enjoy high-quality table tennis equipment. 2. research objects and methods 2.1. research objects the research object is the table tennis used in the table tennis classroom of chinese universities. 2.2. research methods in this paper, the appearance design of a ping-pong ball cleaning and recovery machine is completed by using the methods of literature review and modeling. 2.2.1. literature method this paper reviews and analyzes the domestic and foreign literature on solidworks and cad/cam technology, which provides references, academic background and scientific basis for this paper. 2.2.2. modeling method this paper uses solidworks software and cad/cam technology to complete the appearance design of a table tennis cleaning and recovery machine[2]. 3. results and analysis 3.1. research results 3.1.1. research background 3.1.1.1. introduction to cad/cam technology cad/cam technology is based on computer, peripheral equipment and system software. it includes 2d drawing design and 3d geometric modeling design[3].it is a method for designers to design with the help of computers. cad/cam technology is a result of the amalgamation of human creativity with high-speed computing, immense storage capacity and logical judgment abilities. it has fundamentally transformed modern manufacturing and engineering design, playing a pivotal role with broad applications and substantial significance. its wide acceptance and continued development have sparked industrial revolutions, propelling technological innovation and advancements in various industries such as machinery manufacturing, aerospace, electronics, automotive, and medical equipment. solidworks software, a representative product of cad/cam technology, stands out as an exceptional solution renowned for its outstanding capabilities. it has earned a reputation as one of the finest cad/cam software packages, trusted by professionals worldwide for its extensive features and user-friendly interface. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the integration of cad/cam technology has revolutionized product design, engineering, and manufacturing. by facilitating precise modeling, simulation, and analysis, it empowers designers and engineers to develop intricate and innovative solutions with unparalleled accuracy and efficiency. as a result, product development cycles are accelerated, time-to-market is reduced, and overall product quality is enhanced. furthermore, cad/cam technology has revolutionized collaboration and interdisciplinary work, fostering seamless communication between diverse teams, including designers, engineers, and manufacturers. this ensures a streamlined workflow, minimizing errors and miscommunications. the software promotes higher efficiency, accuracy, and consistency throughout the entire product development process. solidworks, as a flagship cad/cam software, distinguishes itself through its extensive range of features, encompassing 3d modeling, simulation, documentation, and data management. its intuitive interface and extensive libraries of pre-built components simplify the design process, enabling designers to bring their concepts to life swiftly and effectively. the software's robust simulation capabilities allow engineers to analyze the performance and behavior of their designs under various conditions, ensuring optimal functionality and reliability. in conclusion, cad/cam technology has instigated remarkable transformations across industries, driving advancements and nurturing innovation. as an exemplary representative of this technology, solidworks software has played a crucial role in empowering designers and engineers with indispensable tools, facilitating the creation of groundbreaking products, streamlining workflows, and enabling unprecedented levels of creativity and efficiency. 3.1.1.2. introduction to solidworks solidworks is a high-tech company specialized in developing 3d mechanical design software[3].the purpose of the company is to provide powerful cad/cae/cam/pdm systems for design engineers.solidworks, the leading product of solidworks, is a world leader in 3d cad software.in 1995, solidworks launched the first 3d cad system developed based on windows, and became the first computer platform cad system in the world. promoted by solidworks, other relevant software has been successively launched at home and abroad.solidworks is also the first cad company to develop automatic feature recognition featureworks software and internet based electronic drawing publishing tool (e-drawing).in 1997, dassault acquired solidworks with a wholly-owned capital of us $310 million.after the merger, solidworks continued to operate independently, becoming a highquality professional company. solidworks software has pioneered many innovative features, including top-down and bottom-up design.the ability to design relevant design sub components from top to bottom in the assembly environment, so that geometric shapes and components are fully automatic and relevant, and provide consistent interfaces and commands for designers in the fully automatic and relevant design environment.bottom up design refers to the combination of all parts of a product into a designed product, which can also realize the full automation between geometric shapes and parts. the fully automated design environment provides consistent interfaces and commands. in solidworks, users can use various modules and plug-ins, such as part library, feature tools, measurement tools, assembly tools and simulation tools, to design and build various types of 3d models.these tools can help users complete model design efficiently and carry out rapid simulation and analysis. solidworks also provides a wealth of community support and training resources, including online tutorials, video training, community forums and professional training courses. these resources can help users better learn and master the use of solidworks, so as to improve their work efficiency and design quality. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in solidworks, configuration is a very convenient function. users can create variations of multiple parts in a single part and assembly documents, and these parts can be displayed in the same assembly part at the same time.this function is very useful in the specific design process, such as whether the casting blank or the processed state of the part that realizes the sheet metal bending.in addition, solidworks uses configuration to capture changes and modifications in the actual design process, thus meeting a variety of design requirements.solidworks also created a real-time online 3d website (partstream. net) for internet based 3d product catalog management and delivery services, as well as advanced functions such as smartparts, flexible subassemblies, and alternate position views.this is because solidworks has powerful configuration management technology, and other similar software cannot support such advanced features. in short, solidworks is a powerful three-dimensional cad software, which has led the development of many innovative functions in the cad industry. driven by solidworks, the application of 3d cad software has been widely popularized. 3.2. appearance design 3.2.1. cylinder modeling (1) create on the xy planeφ500.then stretch it into a cylindrical shape with a stretching ring. (2) create with pipe commandsφ50, and then use the array command to array the tubes. (3) combine the tube with the extruded cylinder, fillet, and then use the shell command to get the cylinder surface of the cylinder. (4) create on the cylindrical face end face of the cylinderφ50, use the stretching command to get the end cover of the cylinder, and repeat the same command on the other side. (5) the above cylinder modeling is completed. 3.2.2. modeling of bearing (1) create a plane offset 30mm from the cylinder end cap surface. (2) create a box on a plane, and then use the extrude command to create the box. (3) extract the outer contour surface of the cylinder, and then use the trim command to cut the box to get the support. (4) then use the mirror command to get two symmetrical supports. (5) the support modeling is completed. 3.2.3. funnel modeling (1) create a plane 30mm directly above the cylinder. (2) create on a planeφ50, and then use the extrusion command to create a cylinder. (3) at distanceφa 50 mm cylinder creates a plane. (4) create on a planeφ100, use the extrusion command to create a cylinder. (5) use the ruled command toφ50 cylinder andφ100 columns. (6) use the merge command to merge the three parts. (7) use the shell pulling command to obtain the funnel with a thickness of 5mm. (8) funnel[4]modeling is completed. 3.2.4. modeling of motor support plate (1) create a plane 200 mm from the xy plane. (2) create a rectangle on a plane and extrude the support plate with the extrusion command. (3) chamfer the support plate. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (4) the modeling of support plate[5]is completed. 3.2.5. universal wheel and motor modeling (1) universal wheel[6]and motor[7]are downloaded standard parts, which are assembled with import and assembly commands. figure 1: finished product of appearance design (self-made) figure 2: finished product of appearance design (self-made) 4. conclusions and suggestions the development of an all-in-one machine for table tennis recovery and cleaning has solved the issue of concave surfaces and stains on table tennis balls during training. this groundbreaking device restores the ball's smooth surface, eliminating deformities caused by wear and tear. it also efficiently cleans any stains, improving the ball's appearance and performance. by automating the recovery and cleaning processes, the machine saves time and effort, allowing players to focus on their game. this technological breakthrough sets a new standard in table tennis training equipment, ensuring a consistent and optimal playing experience. it fills the shortcomings of low mechanization and low practicability of innovative products in the existing market products. if the table tennis recovery and cleaning machine is equipped during daily training, the efficiency and scientificity of training will be greatly improved, which will be more conducive to the good development of table tennis in china. the integration of an all-in-one table tennis recovery and cleaning machine effectively improves the reuse rate and durability of table tennis balls, while also reducing extra expenses in the process of physical exercise. by restoring the smooth surface of worn-out table tennis balls, the machine eliminates deformities and allows for extended usage, reducing the need for frequent ball replacements. additionally, its efficient cleaning capabilities ensure that the balls remain free from stains and dirt, further enhancing their lifespan. these benefits result in significant cost savings for both professional players and recreational enthusiasts, as they can prolong the lifespan of their table tennis balls, avoiding the constant purchase of new ones. moreover, the machine streamlines the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 6; november december 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ball recovery and cleaning process, saving time and effort for players, coaches, and training facilities. this enables them to focus more on practicing and improving their skills, optimizing their training sessions. overall, this allin-one machine promotes sustainability, reduces expenses, and enhances the efficiency and longevity of table tennis equipment. references yang zhichun, liu bao, lu zhimin et al. a kind of recycled aluminum substrate cleaning agent research [j]. china cleaning products industry, 2023 (05): 33-37. doi: 10.16054 / j.carol carroll nki. cci. 2023.05.009. li hailin, bai shanshan, chen shiwen, fang liujun, lu junhao. analysis on the appearance design of computer mouse [j]. journal of jiamusi vocational college, 2019 (12): 210-211 wang shaohua. on the application of 3d design software in mechanical teaching [j]. china new communication, 2020,22 (05): 202 zuo hongchuan, wu yuhui. structural design and optimization of torque support plate of roller press [j]. cement engineering, 2022 (06): 10-12+28. doi: 10.13697/j.cnki.32-1449/tu. 2022.06.003 [5] ma chao, gai yongling, zhang lifeng, liang qian. design and development of portable car moving device [j]. china equipment engineering, 2022 (10): 112-114 zhu tinglou, sun hongqing. application and practice of intelligent high efficiency energy saving motor system [j]. energy research and utilization, 2022 (04): 52-55. doi: 10.16404/j. cnki. issn10015523.2022.04.002 wang xiaoyan. table tennis characteristics of nano modified plastic materials [j]. plastic additives, 2022 (05): 32-35 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset preparing for the workforce: industry skills and training for employability maria cruz santos university-batangas, philippines abstract: in today's rapidly changing world, learning is no longer confined to traditional educational institutions. lifelong learning has become essential for individuals to stay employable and contribute to societal development. this paper explores the importance of acquiring knowledge, skills, and attitudes beyond formal education and its impact on employability. employment growth is a critical indicator of a nation's economic performance, and the ability to adapt and apply knowledge in different work environments is key to individual and collective success. the study investigates the relationship between employment growth, innovative activity, knowledge workers, and labor employability. it challenges the inclusion of human capital and innovation measures in regional competitiveness indices when competitiveness is defined by rapid employment growth. keywords: lifelong learning, employability, employment growth, knowledge workers, innovation. introduction learning can be obtained through various means and experiences as long as people would be able to gain appropriate information, skills and attitude. it is no longer confined to schools, for humans have to engage in ‘lifelong learning’ in order to keep up with the demand to maintain one’s employability (brinkmann, 2008). application of knowledge to different work environment is the bottom line of how someone has to get into a large picture of the society making contribution to the development of the country. employment growth is an important measure of how a nation or state performs in the economic equilibrium. effectiveness of the immediate policy response and longer-term local economic strategies—may have helped to balance the impacts of personal attributes associated with workers’ employability and their reabsorption into the labour markets (bailey et al., 2012). barkley and dudensing (2011) found out that “there is an inverse association between employment growth rates and innovative activity, knowledge workers, and labor employability. these findings do not support the inclusion of measures of human capital and innovative activity in indices of regional competitiveness if competitiveness is defined as rapid employment growth.” etzkowitz et al. (2012) noted that some industries have this kind of objective “to create a distributed undergraduate educational module that would introduce students to and increase their employability in emerging interface professions at the intersection of university– industry–government, such as technology transfer and intellectual property rights management, incubator and science park management, etc.” it is always important for the future professionals to learn things about information technology as well as mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset entrepreneurship. knowing how to apply these in the actual work environment would provide them better job opportunities and challenging role in the organization. the factor analysis of barkley and dudensing (2011) identified four factor groupings that reflect inputs to the competitiveness process which include innovation inputs, knowledge workers, labor employability, and entrepreneurial environment. they also noted that industrial specialization and industrial composition comprised the two groupings that represent industry structure that measures the entrepreneurial environment and industry structure. these factors provide better understanding of the situation on how to become a dynamic organization towards helping the industry and the economy to be more productive. stuart (2007) explored the challenges and implications, in industrial relations terms, of contemporary labour market policy with regard to learning, training and employability. the presentation of employability assets to prospective employers and the deployment of those assets, reflecting the individual’s ability to act strategically in pursuing opportunities (danson, 2005) is one way for the job seekers to be placed in the right position and employer. this literature review explores the employability and skills required of the industrial sector. there were 14 research articles filtered from sage journal database from january 2000 to november 2015 with the following keywords: ‘industrial’ in the title; ‘skills’ and ‘employability’ in the full text category. the significance of exploring labor markets and skills requirements of industries would provide better understanding for higher education institutions on how they will deliver quality instruction with appropriate student learning outcomes based on the needs and demands of the industries. competitive skills requirement possessing highly qualified technical or professional skills would provide better opportunities to be employed in the local community and abroad. entrepreneurial skill is an important qualification or ability of the graduates of any college degree program to posses because the world is running through business perspective. alonso (2011) emphasized that “the discourse of training in the context of a society which is uniformly presented to people in their daily lives as being ‘knowledge-based’, by demanding of them appropriate levels of employability, entrepreneurship and adaptability”. barkley and dudensing (2011) identified entrepreneurial environment as one of the four factor groupings that reflect inputs to the competitiveness process. students can be encouraged to take risks and become entrepreneurs while it is expected that they can acquire business skills as part of their education (etzkowitz et al., 2012). however, the discourse of the entrepreneur is used misleadingly, as, in addition to a permanent readiness to keep changing jobs and to accept working conditions that are increasingly unstable and less and less well regulated (alonso, 2001). etzkowitz et al. (2012) mentioned about the challenges of knowledge society occupations which is increasingly interdisciplinary in nature that requires cutting – edge skills and capacities. personal initiative is necessary from the employees to learn new skills as they grow personally and professionally in the organization. continuing development of expertise and proficiency especially in the field of information technology would give better opportunities working in a more diverse organization. employees interested in graduate school as part of continuing professional education should engage in experiences like research, applied projects, conference presentations, or journal publications that develop relevant skills as well as build relationships with other members of the profession (shoenfelt et al., 2014). alonso, 2001 noted that “the motto mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of ‘work for those who can work, security for those who can’t’, which is advocated by all the members of the post-neoliberal movement that came to power across much of europe at the end of the 1990s, implies acceptance of the new philosophy that talks of the need to ‘prepare’ people for technological change so that they will be able to adapt as easily as possible to the demands of the labour market, using the above-mentioned euphemism of increasing employability as the basis for its arguments.” workforce training the training allows partially structuring and regulating occupations by setting skill norms and conventions (gray & defilippis, 2014). the identification of the significance of the individual’s employability assets, or personal skills and attributes (danson, 2005) would give better perspective of an individual strength and weaknesses that will serve as the basis for improvements of one’s skills and talents. direct employee participation takes place on the basis of a broad definition of participation aimed at drawing on employees’ skills with regard to both problem setting and problem solving in the context of organizational change (telljohann, 2010). one of the key policy interventions was to offer training opportunities to workers to help them to reskill (bailey et al., 2012). in the environment of heightened global competition and economic insecurity and uncertainty, economies and industries need constant upgrading of skills to remain competitive and dynamic (stuart, 2007). the lack of formal training is a chronic problem for workers in many low-end service occupations. it promotes segmented labour markets and encourages employers to structure jobs that only require low levels of skill (gray & defilippis, 2014). younger, more skilled workers and those who were prepared to commute further generally found work more quickly, whilst for older workers and lower skilled workers, successful adjustment was more problematic (bailey et al., 2012). with regard to many of the training programmes dedicated to those who did not complete their school qualifications or equivalent, there are low or negative returns to investment for many of those suffering social exclusion or other employability obstacles, regardless of the regional or national circumstances (danson, 2005). the government has a responsibility of providing necessary training and development to ensure its people has necessary skills needed by both private and public organizations to cope as industries change, through highquality, flexible education, training, information and mobility programmes (bailey et al., 2012). in terms of gender differences, the labour force was becoming much more oriented towards women, the low skilled, part-time working and temporary, low-paid and non-unionised jobs where career progression was limited (danson, 2005). the support groups of local community members as categorized by more formal learning providers gives soft entry learning which aimed at improving confidence, skills and ultimately the potential of local people for employability (braithwaite et al., 2007). conclusion and recommendation higher education institutions may provide highly practical module which develops students’ entrepreneurial skills, employability, and abilities in idea generation, evaluation of ideas and communication (etzkowitz et al., 2012). continuous learning processes are necessary with the objectives of obtaining broad-based skills training for the labour force comprising social and methodological skills and general knowledge of technology and work organization (telljohann, 2010). employers may strengthen its staff development program to ensure the quality of knowledge and skills of its people are still updated and can still respond to the needs of global mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset market. graduate school studies may enhance learning ability of the employees to keep them abreast with the latest innovations and techniques related to their field of specialization. giving them a chance to nourish their talents and skills will make them assets of the organization.the negative impact of tight labor markets (the labor employability factor) on employment growth is mitigated if the industrial base has a high relative industry wage. a high value for the relative industry wage reflects high labor productivity for the traded sectors in the area economy, and highly productive firms may be less constrained by tight local labor markets (barkley & dudensing, 2011). transitions from basic to higher education and employment may be analyzed to explore the workless household in explaining employability problems and the tendency for problems to become concentrated in certain communities and among certain groups in society (danson, 2005). alonso (2001) emphasized that job seekers are expected to train, retrain or do work placements on their own initiative, and they are encouraged to respond to difficulty in finding employment by setting up their own business or becoming self-employed. training needs analysis of the people is necessary to determine the areas for improvement among the employees. identifying their strengths and weaknesses would create a better picture to develop a comprehensive development plan or program for the people to enrich their mind, spirit and interest to work productively. references alonso, l. e. (2001). new myths and old practices: postmodern management discourse and the decline of fordist industrial relations. transfer: european review of labour and research, 7(2), 268-288. bailey, d., chapain, c., & de ruyter, a. (2012). employment outcomes and plant closure in a post-industrial city: an analysis of the labour market status of mg rover workers three years on. urban studies, 49(7), 1595-1612. braithwaite, r., cockwill, s., o’neill, m., & rebane, d. (2007). insider participatory action research in disadvantaged post-industrial areas the experiences of community members as they become community based action researchers. action research, 5(1), 61-74. brinkmann, s. (2008). changing psychologies in the transition from industrial society to consumer society. history of the human sciences, 21(2), 85-110. barkley, d., & dudensing, r. m. (2011). industrial legacy matters: implications for the development and use of indices of regional competitiveness. economic development quarterly, 0891242410393951. danson, m. (2005). old industrial regions and employability. urban studies,42(2), 285-300. etzkowitz, h., ranga, m., & dzisah, j. (2012). whither the university? the novum trivium and the transition from industrial to knowledge society. social science information, 51(2), 143-164. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gray, m., & defilippis, j. (2014). learning from las vegas: unions and post-industrial urbanisation. urban studies, 0042098014536787. shoenfelt, e. l., stone, n. j., & kottke, j. l. (2014). industrial–organizational and human factors graduate program admission information for undergraduate advisors. teaching of psychology, 0098628314562683. stuart, m. (2007). introduction: the industrial relations of learning and training: a new consensus or a new politics?. european journal of industrial relations,13(3), 269280. telljohann, v. (2010). employee-driven innovation in the context of italian industrial relations: the case of a public hospital. transfer: european review of labour and research, 16(2), 227-241. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset determination of requirements for the development of an online fault reporting system for utility companies iyidobi jonathan chijindu department of electrical and electronic engineering, enugu state university of science and technology, nigeria doi: https://doi.org/10.5281/zenodo.15182999 abstract this research work is therefore targeted at determining the requirements of the system suitable for developing an effective web-based fault reporting system for public utility companies. an electricity distribution company’s fault reporting system with correct system requirements will serve as a viable channel for reporting faults that occur at the users’ end. this will facilitate quick and efficient clearing of these faults for timely restoration of the electricity supply to users. this supports an electricity distribution system that will facilitate reliable and consistent delivery of quality services to users, reduce outages and downtimes, thereby enhancing productivity and national development. to achieve this, different online fault reporting systems were reviewed, including the existing case study power distribution company fault reporting system. the features and functions found present or lacking in the reviewed systems were critically analysed. and then with the help of a survey, determine accurately all requirements needed to build a fault reporting/management system that will not just be effective and efficient but also designed to overcome the lapses observed in the reviewed systems. two groups of potential users were identified: the phcn customers and the phcn staff. phcn customers will use the system to report electrical faults in their domain while phcn staff will use the system for both system/fault management and fault reporting. some requirements were proposed and packaged in the form of a questionnaire and then randomly distributed to the identified two groups of potential users. a total of 55 questionnaires were sent through e-mail to the respondents. the result and analysis of the survey conducted to determine the requirements of the online fault reporting system for ikeja electricity distribution revealed that for the web-based system to be effective and efficient it should possess the following features: dynamic database, web interface, information display page, fault description page, registration and login page, fault update page and track progress page. keywords: development, online, reporting, system, utility academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1.1 introduction public utility companies play a critical role in the socioeconomic lives of every nation. power supply companies, for instance, ensure that the teaming population of the society (commercial and domestic consumers of electricity) is supplied with adequate electric power for commercial, industrial, and domestic activities for the overall sustainability of socioeconomic progress of the society. water supply companies have similar responsibilities, ensuring a steady supply of clean water for both domestic and industrial use. the need for these utility companies to function effectively and efficiently cannot be overstressed. unfortunately, due to the large number of users/customers, the operational infrastructure of these utility companies is usually vulnerable to faults due to high pressure on their facilities. unrectified or delayed fault clearing can result in long outages leading to down times in industries and commercial set ups. the consequences of outages and down time are quite severe both for domestic and commercial users of electricity. this can include but not limited to: high cost of production occasioned by the need to run standby generators for long hours, loss of perishable goods at home and in some commercial establishments due to long power outage, laying off of workers due to reduced working time, etc. the overall impact of long outages stemming from unrectified of delayed system restoration is poor productivity and reduced national development. to ensure reliability and consistent delivery of quality services to users, electricity distribution companies should have a channel for reporting faults that occur at their end to facilitate quick and efficient clearing of these faults for timely restoration of electricity supply to users. this reduces outages and down times thereby enhancing productivity and national development. the ability of an effective fault reporting system to increase the reliability an efficiency of any system cannot be over stressed. this is because it allows service providers to be in continuous touch with their customers, getting to know the faults and issues developing in their systems and helping to fix them as fast as possible. fault reporting systems provides necessary data relating to faults and maintenance and which are very useful in speedy fixing of faults and effective planning against faulting repetition [1]. online self-reporting system that allows patients to report toxicity symptoms has the ability to provide detailed and correct clinical data, facilitate speedy interventions in patients’ cases, uplift patients’ health and safety [2], improve level of interaction between patients and the hospital and help standardise data gathered from different locations. similarly. online incidence reporting system developed for a japanese hospital has not only made patients safer, but has increased the speed of attending to patients and reduced situations that cause errors [3]. this research work is therefore devoted to reviewing different online fault reporting systems, analysing the features of and functions found present or lacking in the reviewed systems so as to aggregate suitable system requirements needed to build a fault reporting/management system that is effective and very efficient. i. methodology the method adopted in this research involves reviewing different online fault reporting systems. analysing the features of and functions found present or lacking in the reviewed systems, and with the help of a survey using academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the result of the analysis to accurately aggregate all requirements needed to build a fault reporting/management system that will not just be effective and efficient but designed to overcome the lapses observed in the reviewed systems. two groups of potential users of the case study utility company (phcn) participated in the survey to determine which requirements (obtained from result of the analysis of the review of other online reporting system) are critical for the case study system. the two groups are the phcn customers and the phcn staff. phcn customers will use the system to report electrical faults in their domain while phcn staff will use the system for both system/fault management and fault reporting. based on the result of the analysis of features/functionalities of other fault reporting systems studied, system requirements were proposed and packaged in form of questionnaire and then randomly distributed to the identified two groups of potential users. a total of 55 questionnaires were sent through e-mail to the respondents. results of the survey were then analysed to determine the accurate requirements of the case study system, 2.1 phcn fault online reporting system. the case study power distribution company for this research is the ikeja power holding company of nigeria (phcn). the ineffectiveness of the current phcn online fault reporting system in creating a platform for quality fault reporting and management due to the absence of some key features and functionality inspired the motive for this project in the first place. as observed in academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2.1: a screen shot of the current phcn complaint form [4]. 2.2 other fault reporting system access east sussex online fault reporting system: this system permits individuals and staff in the east sussex area and environs to report faults or issues in the services offered by the council in their local areas. though the system does not require a reporter to register or log in before logging a report; it provides fields for selecting fault location, fault category and further descriptions. also fault status can be tracked in this system [5]. kent county council fault reporting system: this system allows people in the kent county council area to report faults on roads, street lightings, environment and related facilities. no login or registration is required to use the system but personal details of reporter (names, telephone number e-mail address, etc) are required. fields for filling in fault details and location are also provided. reporters can check the progress of fault correction using this system [6]. mahanagar telephone nigam limited fault reporting system (mtnl): the fault reporting system allows their subscribers to report faults in their telephone, garuda or broadband services. the system was designed to academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset allow users select concerned service before being taken to the page for selecting fault category and filling up the field for telephone number and then fault details. only those selecting the garuda services are required to register and login. users can check progress of fault correction in this system [7]. city of london fault reporting system: the system allows users to report a variety of faults around the city of london. the system provides for the selection of fault category and then fault location. fields for fault details and reporter’s personal details must also be filled before report can be submitted. no login is required. also, users cannot to check the progress of fault rectification with the system [8]. the cabrini college (usa) information technology and resources reporting system: the system allows users (mainly students, staff and clients) to report problems developing in the information technology facilities purchased from the college or those being used by the college's staff and students. login is required to use the system, though the system generates the password needed to login each time a user wants to use the system. as a result, registration is not required. however, a user is required to provide his details and details of the fault during fault reporting. reasonable information was provided by the system as regards the need to report faults using the system. it does not provide any means of tracking progress of fault correction [9]. problem reporting system for users of online-teach yourself system owned by the university of the state of new york (nysed): the system does not require any login before you can use the system and as such, no registration is required. details of the problem reporter and details of the fault itself must be provided to successfully login a problem. reasonable information relating to the need to use the system and how to successfully use the system were provided [10]. north american and uk based daeja image system problem reporting system: the system allows their clients/customers to report problems encountered in the use their in-browser java applet image viewer "viewone". no registration and login is required to use the system. however very detailed information about the problem reporter and the problem being reported is required. brief information about the process of problem reporting is also provided [11]. the city of tallahassee problem reporting system, usa: this system helps residents to report issues in any of the services offered by the city governing authorities. no registration and login are required. details of problem reporter required as well as that of the problem being reported. reasonable information about the usefulness of the system and how to use it was provided [12]. i. modeling and analysis 3 comparative analysis from the above review of similar systems, we can observe that unlike the phcn system, the other systems described, even though they lack certain vital features and functionalities have more capacity to build up a fault database. this is because the other systems made provisions for collecting data relating to faults reported (for instance: fault type/category and fault location), this information can be very useful for future planning as it relates to reducing frequency and duration of faults in the system. it was however observed that out of the nine academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset systems compared, only two systems require the user to register or log into the system before being able to report fault. even though this can increase the number of people willing to make fault report; systems without any provision for registration/login will remain very vulnerable to abuse, and the risk of logging in of unreliable information is also high. all the systems highlighted above were found to have required users to provide some personal details for identifying them. most importantly, personal details of users will help service providers to locate both the fault and the fault reporter to facilitate prompt fixing of the fault. this is also a good strategy of limiting false report but is not enough to replace the need for registration and logging in. we can also observe from table 3.1 that out of the nine systems compared, only three systems made provisions for tracking the progress of fixing of fault reported. one can observe from the table that all the systems (except phcn with rating “low”) studied had only a moderate capacity to build up a comprehensive database needed to plan against fault re-occurrence. this system will be designed to improve on this area such that the system will have a comprehensive database to plan against frequent fault occurrences. also, on the suitability for fault management, table 3.1 shows that all the systems (except phcn with rating “low”) studied was rated moderate. this system will be designed to be an efficient and effective tool for fault management so as to help phcn achieve high level of customer satisfaction. about 67% of the systems compared did not make provision for tracking of progress of fault correction. this system will improve on this area and as such will be designed to offer users a means of tracking the progress of fault clearing. finally, on the ability to educate the users on fault issues about 50% of the compared systems were rated minimum while 50% was rated moderate. this is also another area of concern. this system will be designed to be an effective means of educating phcn customers on fault and safety issues. generally, it can be observed that the phcn system performed poorest of all the systems studied, and other systems studied performed either average or below average when rated against the outlined criteria. this system will therefore be designed to make up for the deficiencies observed in the systems studied while retaining their positive features. phcn (2011), what is currently playing the role of a fault reporting system is actually a complaint reporting system. the system allows any person make a complaint or report without first being registered or logging into the system. after selecting a zone and a business unit, the system provides the reporter with fields for entering his name, e-mail address, phcn account number and then the report or complain. the above details are grossly insufficient for building up a comprehensive database for the company. this so because, as can be seen from figure 2.1, fields for logging in attributes of the fault (such as type of fault, date of occurrence, time of occurrence, address, etc) itself are totally lacking. there is also no feedback system that allows phcn staff to update fault or complaint status neither does such feedback exist for allowing users to check progress of fault correction. academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2.1: a screen shot of the current phcn complaint form [4]. 2.2 other fault reporting system access east sussex online fault reporting system: this system permits individuals and staff in the east sussex area and environs to report faults or issues in the services offered by the council in their local areas. though the system does not require a reporter to register or log in before logging a report; it provides fields for selecting fault location, fault category and further descriptions. also fault status can be tracked in this system [5]. kent county council fault reporting system: this system allows people in the kent county council area to report faults on roads, street lightings, environment and related facilities. no login or registration is required to use the system but personal details of reporter (names, telephone number e-mail address, etc) are required. fields for filling in fault details and location are also provided. reporters can check the progress of fault correction using this system [6]. academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mahanagar telephone nigam limited fault reporting system (mtnl): the fault reporting system allows their subscribers to report faults in their telephone, garuda or broadband services. the system was designed to allow users select concerned service before being taken to the page for selecting fault category and filling up the field for telephone number and then fault details. only those selecting the garuda services are required to register and login. users can check progress of fault correction in this system [7]. city of london fault reporting system: the system allows users to report a variety of faults around the city of london. the system provides for the selection of fault category and then fault location. fields for fault details and reporter’s personal details must also be filled before report can be submitted. no login is required. also, users cannot to check the progress of fault rectification with the system [8]. the cabrini college (usa) information technology and resources reporting system: the system allows users (mainly students, staff and clients) to report problems developing in the information technology facilities purchased from the college or those being used by the college's staff and students. login is required to use the system, though the system generates the password needed to login each time a user wants to use the system. as a result, registration is not required. however, a user is required to provide his details and details of the fault during fault reporting. reasonable information was provided by the system as regards the need to report faults using the system. it does not provide any means of tracking progress of fault correction [9]. problem reporting system for users of online-teach yourself system owned by the university of the state of new york (nysed): the system does not require any login before you can use the system and as such, no registration is required. details of the problem reporter and details of the fault itself must be provided to successfully login a problem. reasonable information relating to the need to use the system and how to successfully use the system were provided [10]. north american and uk based daeja image system problem reporting system: the system allows their clients/customers to report problems encountered in the use their in-browser java applet image viewer "viewone". no registration and login is required to use the system. however very detailed information about the problem reporter and the problem being reported is required. brief information about the process of problem reporting is also provided [11]. the city of tallahassee problem reporting system, usa: this system helps residents to report issues in any of the services offered by the city governing authorities. no registration and login are required. details of problem reporter required as well as that of the problem being reported. reasonable information about the usefulness of the system and how to use it was provided [12]. ii. modeling and analysis 3 comparative analysis from the above review of similar systems, we can observe that unlike the phcn system, the other systems described, even though they lack certain vital features and functionalities have more capacity to build up a fault database. this is because the other systems made provisions for collecting data relating to faults reported (for academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset instance: fault type/category and fault location), this information can be very useful for future planning as it relates to reducing frequency and duration of faults in the system. it was however observed that out of the nine systems compared, only two systems require the user to register or log into the system before being able to report fault. even though this can increase the number of people willing to make fault report; systems without any provision for registration/login will remain very vulnerable to abuse, and the risk of logging in of unreliable information is also high. all the systems highlighted above were found to have required users to provide some personal details for identifying them. most importantly, personal details of users will help service providers to locate both the fault and the fault reporter to facilitate prompt fixing of the fault. this is also a good strategy of limiting false report but is not enough to replace the need for registration and logging in. we can also observe from table 3.1 that out of the nine systems compared, only three systems made provisions for tracking the progress of fixing of fault reported. one can observe from the table that all the systems (except phcn with rating “low”) studied had only a moderate capacity to build up a comprehensive database needed to plan against fault re-occurrence. this system will be designed to improve on this area such that the system will have a comprehensive database to plan against frequent fault occurrences. also, on the suitability for fault management, table 3.1 shows that all the systems (except phcn with rating “low”) studied was rated moderate. this system will be designed to be an efficient and effective tool for fault management so as to help phcn achieve high level of customer satisfaction. about 67% of the systems compared did not make provision for tracking of progress of fault correction. this system will improve on this area and as such will be designed to offer users a means of tracking the progress of fault clearing. finally, on the ability to educate the users on fault issues about 50% of the compared systems were rated minimum while 50% was rated moderate. this is also another area of concern. this system will be designed to be an effective means of educating phcn customers on fault and safety issues. generally, it can be observed that the phcn system performed poorest of all the systems studied, and other systems studied performed either average or below average when rated against the outlined criteria. this system will therefore be designed to make up for the deficiencies observed in the systems studied while retaining their positive features. table 3.1: comparative analysis of different fault reporting systems capacity to build comprehensi ve database provision for checking fault update by users suitability for fault manageme nt request for users’ login and registration provision of information on fault issues academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset phcn system low non low non non east sussex system moderate yes moderate non minimum kent council system moderate yes moderate non minimum mtnl system moderate yes moderate yes (in one section only) minimum city of london system moderate non moderate non moderate the cabrini college (usa) moderate non moderate yes moderate state of new york university moderate non moderate non moderate daeja image system moderate non moderate non minimum city of tallahassee moderate non moderate non moderate iii. results and discussion 4 results of primary research the aim of this primary research is to involve the potential users in determining the requirements of the system. two groups of potential users have been identified: the phcn customers and the phcn staff. phcn customers will use the system to report electrical faults in their domain while phcn staff will use the system for both system/fault management and fault reporting. some requirements were proposed and packaged in form of questionnaire and then randomly distributed to the identified two groups of potential users. a total of 55 questionnaires were sent through e-mail to the respondents. this was the quickest and most practical means of distributing the questionnaire as majority of the respondents live in nigeria. out of the number sent out, 11 academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset responded (10 phcn customers and 1 phcn staff) and their responses are presented in table 4.1 and table 4.2. the likert scale questionnaire was used because it is easy to respond to and analyse, and has the ability to show the extent to which a respondent approves or disapprove a view. there are ten likert formed questions and two open ended questions. analysis of primary research (questionnaire) table 4.1: tabulation of responses from phcn customers questions strongly agree score (%) agree score (%) disagree score (%) strongly disagree score (%) 1 a comprehensive database for capturing faults reported in customers’ domains and phcn facilities will assist phcn in fault management, and planning against high outage duration and frequency. 90 10 0 0 2 an effective and efficient web interface (in form of a dynamic website) for the above system so as to allow phcn customers and monitoring staff to report electrical faults in their domain, online, for prompt response by phcn will improve phcn services delivery to their customers. 60 50 0 0 3 the system should be displaying vital information that will educate users on fault issues and how best to handle phcn facilities so as to minimise fault occurrences 70 30 0 0 academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4 vital information relating to the reported faults (such as fault type/category, fault time, description, location, etc,) should be captured by the database. 70 30 0 0 5 such a system should require users to register and obtain a user id and password before being able to use the system so as to regulate users’ activities in the system. 33.3 0 11.1 0 6 the system should also be able to capture some details (name, address, phone number, email address) about the fault reporter to help in reaching him and the fault reported. 80 20 10 0 7 rectification team should be able to update the system to indicate the status of the fault. 70 30 0 0 8 phcn customers should be able to track or check the status (update) on the rectification of reported faults. 60 30 10 0 9 phcn management should be able to use the system to allocate fault rectification jobs to their field staff. 40 60 0 0 10 the system should be able to prevent multiple reporting of faults that has already been reported. 50 20 30 0 academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4.1: component bar chart showing the response of phcn customers to the questionnaire. figure 4.2: component bar chart showing the response of phcn staff to the questionnaire. academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset note: in the two figures above, the symbol ‘q’ stands for question in the questionnaire. for example, q1 in the charts represents question 1 in the questionnaire. analyses of requirements from the tables 4.1 and 4.2 and figures 4.1 and 4.2 above, it is obvious that two groups of intended users (phcn customers and staff) are fully in support of the proposed requirements for the system. this follows therefore that the intended users accept that a comprehensive database for capturing faults reported in customers’ domains and phcn facilities will assist phcn in fault management, and planning against high outage duration and frequency. this shows that from the users’ perspective, the project is worthwhile and will help in gathering data that will facilitate speedy fault fixing and drastic reduction of fault re-occurrence, which will be made possible by adequate planning and fault management as regards the need for a web interface that will enable online report of faults, we observe from the tables and figures above that both sets of the respondents showed resounding support for the provision of web interface that will allow users to log in their fault reports, online, using the internet. this affirms that the initial proposal to incorporate a web interface in this design is in line with users’ desire on the project. on the need for the system to be able to display vital information that will educate users on fault issues and how best to handle phcn facilities so as to minimise fault occurrences; the tables and charts above shows an overwhelming interest in the users to see the system be a source of enlightenment to them on issues relating to faults, safety measures and best practices in handling phcn facilities. from the tables and chats above, we observe also that respondents are of the view that fault reporters should provide the system with vital information relating to the fault (such as fault type, fault time, location, etc) for an automatic documentation in the database and also to equip the rectification team with the right information needed for speedy rectification of the fault. the tables 4.1 and 4.2 and figures 4.1 and 4.2 above also show that both sets of users support the idea of user registration and login as a means of regulating users’ activities in the system. the tables and charts above also reveal that respondents are backing the need for users of the system to provide their details and details of the fault they are reporting. this will help phcn repair team to respond quickly to the fault reported. both groups of users are also in support of the system being able to allow phcn management to update the system and use the system for planning and fault management. they also support the idea of users being able to track progress of faults reported with the system. even though majority of the respondents in both groups support the idea of the system preventing multiple reporting of faults; a significant number of phcn customers (30%) disagreed with this view point. they argued that users can employ multiple reporting of a particular fault to indicate how serious a fault is so as to push phcn to act swiftly on it. the disadvantage of multiple reporting is the tendency to have the same information in the academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset database thereby causing redundancy and occupying more memory space. this could also reduce the speed of the system. effort will be made to see that multiple reporting is avoided as much as possible in this system. iv. conclusion some respondents outlined the existing means of reporting faults to phcn. the means outlined are: physical visiting of the phcn nearest office, through phone calls and through e-mail messages. these methods can still work but reporting fault by going physically to the phcn office can be time wasting, stressful and costly. while phone calls and e-mails remain fast means of fault reporting, they are not able to systematically capture and store fault information in an organised manner that will facilitate good planning and management of fault related issues in phcn. fortunately, the proposed online fault reporting/management system will serve not only as a very fast means of fault reporting but will provide a bank of regularly updated information needed to promptly respond to faults reported and plan well against their re-occurrence. it was concluded that while phone calls and e-mails remain fast means of fault reporting, they are not able to systematically capture and store fault information in an organised manner that will facilitate good planning and management of fault related issues in power distribution companies. fortunately, the proposed online fault reporting/management system will serve not only as a very fast means of fault reporting but will provide a bank of regularly updated information needed to promptly respond to faults reported and plan well against their re-occurrence. v. references sematech (1999) ‘failure reporting analysis and corrective action system’ available at: http://www.sematech.org/docubase/document/2332agen.pdf (accessed: 11th march, 2011). e. basch, d. artz, d. dulko, k. scher, p. sabbatini, m. hensley, n. mitra, j. speakman, m. mccabe, and d. schrag, (2005) ‘patient online self-reporting of toxicity symptoms during chemotherapy’ journal of clinical oncology, volume 23 number 15. available at: http://jco.ascopubs.org/content/23/15/3552.full.pdf (accessed: 9th march, 2011). k. y. nakajima, and h. t. kurata, (2005) ‘a web-based incident reporting system and multidisciplinary collaborative projects for patient safety in a japanese hospital’ qual saf health care 2005;14:123–129. available at: http://www.ncbi.nlm.nih.gov/pmc/articles/pmc1743978/pdf/v014p00123.pdf (accessed: 9th march, 2011). power holding company of nigeria (phcn) (2011), ‘online complaint reporting system’ available at: http://www.phcnonline.com/timsclient/(lscnyq45d2df3155zd2o4r3u)/generalcomplain.aspx (accessed: 11th march, 2011). http://www.sematech.org/docubase/document/2332agen.pdf http://www.sematech.org/docubase/document/2332agen.pdf http://jco.ascopubs.org/content/23/15/3552.full.pdf http://jco.ascopubs.org/content/23/15/3552.full.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/pmc1743978/pdf/v014p00123.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/pmc1743978/pdf/v014p00123.pdf http://www.phcnonline.com/timsclient/(lscnyq45d2df3155zd2o4r3u)/generalcomplain.aspx http://www.phcnonline.com/timsclient/(lscnyq45d2df3155zd2o4r3u)/generalcomplain.aspx academic journal of science, engineering and technology vol. 8, issue 3; may-june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset east sussex county council (2011), ‘online fault reporting system’ available at: http://194.238.70.74/faultreport/faultintro.aspx (accessed: 11th march, 2011). kent county council (2011), ‘online fault reporting system’ available at: http://www.kent.gov.uk/khsfaults/ (accessed: 11th march, 2011). mahanagar telephone nigam limited (mtnl) ‘online fault reporting system’ (2011), available at: http://203.94.244.173:7777/vcare/index.jsp (accessed: 12th march, 2011). city of london (2011) ‘fault reporting system’ available at: http://www.cityoflondon.gov.uk/faultreporting/ (accessed: 12th march, 2011). cabrini college usa (2011) ‘online reporting system’, available at: https://app1.cabrini.edu/problemreporting/ (accessed: 20th april 2011). nysed (2011), ‘nysd online problem reporting system’, available at: https://secureforms.nysed.gov/ohe/tcert/technical.cfm (accessed: 20th april 2011). daeja image system (2011) ‘image system problem reporting system’, available at: http://www.daeja.com/contact/problem-report.asp (accessed: 20th april 2011). tallahassee system, usa (2011). ‘tallahassee trouble reporting system’, available at: http://www.talgov.com/trouble.cf (accessed: 20th april 2011). http://194.238.70.74/faultreport/faultintro.aspx http://194.238.70.74/faultreport/faultintro.aspx http://www.kent.gov.uk/khsfaults/ http://www.kent.gov.uk/khsfaults/ http://www.kent.gov.uk/khsfaults/ http://203.94.244.173:7777/vcare/index.jsp http://203.94.244.173:7777/vcare/index.jsp http://www.cityoflondon.gov.uk/faultreporting/ http://www.cityoflondon.gov.uk/faultreporting/ http://www.cityoflondon.gov.uk/faultreporting/ https://app1.cabrini.edu/problemreporting/ https://app1.cabrini.edu/problemreporting/ https://app1.cabrini.edu/problemreporting/ https://secureforms.nysed.gov/ohe/tcert/technical.cfm https://secureforms.nysed.gov/ohe/tcert/technical.cfm http://www.daeja.com/contact/problem-report.asp http://www.daeja.com/contact/problem-report.asp http://www.daeja.com/contact/problem-report.asp http://www.daeja.com/contact/problem-report.asp http://www.talgov.com/trouble.cf http://www.talgov.com/trouble.cf academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset isolation and identification of common bacteria that affect beer produced from rice and sorghum malts during fermentation ogunbodede, t.t. department of applied microbiology and brewing, enugu state university of science and technology (esut) enugu, nigeria doi: https://doi.org/10.5281/zenodo.13912080 abstract: analytical studies were carried out to isolate and identify common bacteria that affect beer produced from mass rice and white sorghum malts during fermentation. rice and sorghum malts were used in the course of this research to produce beer using a commercial yeast (saccharomyces cerevisiae). worts were obtained by infusion mashing and analysed for their physicochemical properties before wort boiling and subsequent pitching of the yeast (saccharomyces cerevisiae) to commence fermentation that lasted seven days. isolation of bacteria was done by culturing the beer samples on nutrient, macconkey and de man rogosa and sharpe (mrs) agar plates and incubated for 48 hours. morphological and microscopic analysis were used to identify the bacterial isolates. results of wort analysis gave original gravity (1.030 and 1.0320ρ), sugar (78.0 and 7.55)0brix, ph (5.6 and 5.4) and viscosity (1.21 and 1.13) cp for the wort samples from sorghum and rice malts, respectively. the beer after analysis gave specific gravity (1.005 and 1.004)0, sugar (1.03 and 1.29)0brix, ph (4.0 and 4.1) and %alcohol (3.66 and 3.27) v/v. the total bacterial counts was 1.2x104 and 1.1x1047cfu/ml and the lactic acid bacterial count ranged from 1.3x104–1.2.x104cfu/ml for beer produced from rice and sorghum malts, respectively with no coliform count. the bacterial isolates identified included streptococcus, lactobacillus and micrococcus species. this study confirmed the prevalence of contaminating bacteria on beer samples produced from rice and sorghum malts when fermentation is carelessly handled. keywords: bacteria, beer, rice, sorghum, malt. introduction beer is a favourite and highly drunk beverage, since it holds desirable sensory attributes as well as nutritional/medicinal characteristics (asano et al., 2009). beer is a very stable beverage in terms of microbiological deterioration; nevertheless, any microbiological spoilage resulting from the malting, brewing, or storage process can negatively impact beer quality and have an adverse financial effect on the brewery industry. (suzuki et al., 2008). some gram-positive and gram-negative bacteria, wild yeast, and molds are examples of spoilage microorganisms. many traditional and advanced biotechnological techniques have been applied for qualitative and quantitative determination of mentioned microorganisms (vaughan et al., 2005). beer is a brewed mailto:topacademicjournals@gmail.com https://doi.org/10.5281/zenodo.13909197 academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset beverage consisting of malt, hop, water and yeast, which is drunk world-wide. beer is the world’s third-most consumed beverage, because of its pleasant sensory and health attributes (sohrabvandi et al., 2010). surveys have shown that light to moderate consumption of beer can provide various impacts on humans‟ health, including nutritional benefits, anti-carcinogenic and anti-mutagenic effects, reduction of cardiovascular disease (cardioprotective effect), immune system stimulation, hypolipidemic effect, anti-osteoporosis effect and reduced risk of dementia (sohrabvandi et al., 2010). microbial spoilage is a continuous challenge for the food industry, although beer is very restrictive to bacteria (due to its low ph, high acidity and different anti-microbial compounds) and the beer-spoiling organisms are limited to a few genera (shabani and devolli, 2010). the effects of the spoilage bacteria range from relatively minor changes in beer such as off-flavours and aroma defects (i.e. the buttery off-odour of diacetyl), turbidity problems, ropiness, abnormal attenuation rates and reduced yeast crops. these unwanted changes bring millions of dollars losses per year (march et al., 2005). the majority of spoilage organisms are either obligate anaerobes of the species pectinatus and megasphaera, or lactic acid bacteria, primarily belonging to the genera lactobacillus and pediococcus. out of the lactobacilli species, the certain number of strains is able to multiply in the beer medium and cause spoilage. the most common occurring spoilage bacteria in beer are lactobacillus brevis and lactobacillus lindneri, respectively (anli and alkis, 2010). in addition, there are many wild types of yeast causing spoilage in beer including, saccharomyces cerevisiae and candida pelliculosa. however, they cause spoilage problems with greater severity than bacteria. additionally, malt and beer can be adversely affected by fusarium infections in grains (anli and alkis, 2010). beer when carelessly handled during the production processes, is affected by countless microorganisms during fermentation. hence, contaminated beer is dangerous to the consumers. there have been very little studies on the isolation and identification of microorganisms that contaminate beer during fermentation. hence, this study. the aim of this study is to isolate, characterize and identify common bacteria that affect beer produced from rice and sorghum malts during fermentation. materials and methods sources of materials rice (mass rice) and sorghum (white varieties) were purchased from eke-agbani in nkanu-west of enugu state while hops, yeast (saccharomyces cerevisiae), nutrient agar, macconkey agar, de man, rogosa and sharpe (mrs) agar and other materials/equipment used to carry out this project research were supplied by the laboratory section of the department of applied microbiology and brewing, esut. methods the methods of analysis employed in the evaluation of malt, wort and beer were based on the recommended methods of analyses of the institute of brewing (iob) and american society of brewing chemists (asbc) (agu, 2006). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset malting process malting was done by selecting the grain first, followed by steeping (the steep liquor was changed at 6 hr interval after which the grains were allowed to have a 2 hr air rest) for 40 hr, casting (the grains were drained off water and heaped on a jute bag) for 24 hr, germination (the grains were spread out on the jute bag very well for uniform aeration and germination) for 3 days and kilning (the malt is dried to reduce the moisture content). after kilning, the rootlets were removed by using fiction (abrasion). milling the rice and sorghum malts were milled using milling machine to obtain moderately coarse grits used for mashing. mashing process two conical flasks were washed properly and labelled according to the malted grain used (50g of white sorghum malt and 50g of rice malt). distilled water (360ml) was added into each of the conical flasks containing ach malts. one millilitre (1ml) of exogenous enzymes; amyloglucosidase, fungamyl (-amylase), thermamyl (amylase) and neutrase (proteinase) were added into each of the conical flask containing the samples and shaken properly. the conical flasks were covered with aluminium foil and placed in a water bath to commence mashing process. the temperature was raised to 350c and maintained for 30mins. the temperature was raised again to 450c and maintained for 30mins for beta-glucanase activities. the temperature was raised again to 500c and maintained for 30oc for proteolysis. the temperature was further raised to 630c and maintained for 1 hour for beta-amylase activities. finally, the temperature was raised to 720c and maintained for 30mins to allow for the activities of alpha-amylase. one (1) drop of iodine solution was added to check for saccharification and vigorously boiled for 10mins after a complete saccharification with yellow colouration as evidence. the essence of vigorous boiling for extra 10mins is to mash off. the samples (mashes) were allowed to cool and filtered using filter cloth to obtain a clear solution known as worts. wort analysis the parameters determined were original gravity (o.g) (o), sugar (obrix), ph, flow rate (sec), viscosity (cp), temperature (oc) and reducing sugar (glucose and maltose). this was done using the method of the methods of analysis of the institute of brewing. wort boiling this was carried out before fermentation to sterilize the worts, inactivate the enzymes and extract the hop constituents. the worts were poured in a 500ml conical flask and arranged in a pot on a burning gas cooker. hops (isomerised) was added and boiled for 11/ 2 hr. wort cooling and filtration the hopped boiled worts were cooled to room temperature using heat exchanger technique by placing the conical flasks in a big basin containing cold water. the separation of hop debris and the coagulant protein (trub) from the wort was done with the help of sterile muslin cloth and filter. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wort fermentation the cooled and aerated worts were now ready for yeast fermentation. strain of saccharomyces cerevisiae was employed for the fermentation process. the yeast was first reconstituted by mixing 20g of yeast, 10g of glucose with water in a container. it was shake vigorously and checked for pressure which signified that the yeasts were back to life. ten (10ml) of yeast inoculum was added to each wort sample (pitching), the container was open to allow contamination by bacteria. at the end primary fermentation which last for 7days, the green beer samples were analysed for physicochemical properties and possible contamination by bacteria. beer analysis determination of alcoholic content the percentage alcohol by weight of each green beer sample was determined by subtracting the final gravity of the beer from the original gravity of wort and multiplying by 0.129. calculation (original gravity of wort – final gravity of beer) x 0.129 determination of apparent fermentability the apparent fermentability is determined by subtracting the original gravity from the specific gravity divided by the original gravity and multiplying by 100% calculation original gravity – specific gravity x 100 original gravity 1 isolation of bacteria from the beer samples all the media used were produced according to their manufacturer’s instruction. about 0.5ml of each serially diluted beer samples (10-4) were dropped on molten nutrient, macconkey and mrs agar plates and spread on the surface of the medium with a sterile wire loop. nutrient and macconkey agar plates were incubated at 30oc for 24 hr. mrs agar plates were incubated at 37°c for 48 hr. colonies exhibiting a surrounding clear zone were observed and counted. distinct colonies observed in the incubated medium were transferred into freshly prepared nutrient agar plates respectively. this was done to obtain a pure culture of each isolates. identification of bacterial isolates characterization and identification of bacterial isolates were based on standard microbiological methods including gram staining, morphological and cultural characteristics on media plates. biochemical tests such as catalase, coagulase, indole, oxidase, citrate and urease tests were also carried out to determine their biochemical properties. results wort analysis this study showed bacteria that affect beer fermentation. table 4.1 shows the result of wort analysis with original gravity of 1.030 and 1.0320ρ for worts produced from mass rice variety and white sorghum variety, respectively. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 1: wort analysis samples original gravity (0ρ) sugar (obrix) ph temp (oc) flow rate (sec) viscosit y (cp) reducing sugar (mg/l) glucose maltose a 1.032 8.04 5.6 28 21.40 1.21 54.73 88.79 b 1.030 7.55 5.4 29 20.11 1.13 54.73 88.79 key: a = wort produced from sorghum malt, b = wort produced from rice malt. beer analysis after primary fermentation table 4.2 showed result of beer analysis after primary fermentation with specific gravity of 1.005 and 1.0040ρ and alcohol of 3.27 and 3.66%v/v for beer produced from mass rice variety and white sorghum variety, respectively. table 2: beer analysis after primary fermentation samples specific gravity (o) sugar (0brix) ph temp (oc) % alcohol apparent fermentability (%) a 1.004 1.03 4.0 25 3.66 87.5 b 1.005 1.29 4.1 25 3.27 83.5 key: a = wort produced from sorghum malt, b = wort produced from rice malt. mean total bacterial counts from beer samples table 4.3 shows the mean total bacterial counts from beer samples, the total bacterial counts was 1.2x104 and 1.1x1047cfu/ml and the lactic acid bacterial count ranged from 1.3x104 – 1.2.x104cfu/ml for beer produced from mass rice variety and white sorghum variety, respectively with no coliform count. table 3: mean total bacterial counts from beer samples (cfu/ml) samples source total bacterial count (nutrient agar) total coliform counts (macconkey agar) lactic acid bacteria count (mrs agar) a 1.1x104 1.2 x104 b 1.2x104 1.3 x104 key: a = wort produced from sorghum malt, b = wort produced from rice malt. identification scheme of the bacterial isolates table 4.4 indicates the colony characteristics of the isolates identified along with their biochemical, gram reaction and microscopic examination. the isolates identified includes streptococcus, lactobacillus and micrococcus species. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4: identification scheme of the bacterial isolates key: mrs = man regosa sharpe agar, cat = catalase test, ind = indole test, oxi = oxidase test, gl = glucose, f = d-fructose, ml= maltose, ma = mannitol, la = lactose, + = positive, — = negative, a = acidic, ag = acidic and gas, g = gas, +ve = positive, —ve = negative. discussion bacteria are isolated from beer samples produced from rice and local sorghum malts. the detection of microbial contamination in the food and beverage industry, specifically brewing, is vital for quality control purposes (condina et al., 2019). the detection of beer spoilage bacteria in the brewery is done using pcr or conventional isolat es type growth appearance of media biochemical test possible organisms gram stain cat in d ox i sugar fermentation gl f ml ma la a large mucoid creamy colonies on mrs agar + short rod in chains — — — a g a a a a lactobacillu s sp. b small creamy mucoid colonies on mrs agar + cocci in chains + — — a a a g a a streptococc us sp. c large creamy mucoid colonies on nutrient agar + short rod in chains — — — a a a g ag a lactobacillu s sp. d milky, round, raised, medium, buttery, opaque, smooth colonies on mrs agar + cocci in cluste rs and pairs — — — a a a a a micrococcu s sp mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cultivation on selective media, according to current standard microbiological quality control procedures. cultivation on selective agar is still used since pcr is expensive and requires known primers to identify a limited and specific number of microorganisms. the sweet worts produced from local sorghum and rice malts showed good physicochemical properties when analysed, as required for good for brewing. the results of wort analysis as recorded in table 4.1 showed original gravity of 1.032 and 1.0300ρ, sugar level (8.0 and 7.55)0brix, ph (5.6 and 5.4) and viscosity (1.21 and 1.13)cp for worts produced from sorghum and rice malts, respectively. the results showed rice and local sorghum malts possess good brewing properties. this result is similar to the result of lyumugabe et al. (2015). the worts were allowed to ferment and analysed after primary fermentation. the results of beer analysis after primary fermentation showed the gravity, sugar and ph to reduce and alcohol produced. the specific gravity of the beer samples were 1.004 and 1.0050ρ, sugar (1.03 and 1.29obrix) and alcohol (3.66 and 3.27) %v/v. this indicates the activities of yeasts on the wort (lyumugabe et al., 2012). determination of bacterial contamination on the beer samples was positive as discrete colonies were found on the nutrient agar, macconkey agar, de man, rogosa and sharpe (mrs) agar plates after incubation. the total bacterial counts was 1.2x104 and 1.1x1047cfu/ml and the lactic acid bacterial count ranged from 1.3x104 – 1.2.x104cfu/ml for beer produced from mass rice variety and white sorghum variety, respectively with no coliform count. this result agrees with the findings of suzuki et al. (2008) streptococcus, lactobacillus and micrococcus species are the bacteria identified after being characterized morphologically, examined microscopically (gram stain) and biochemical tests. this result is similar to the findings of bischoff et al. (2009). the presence of this organism in beer indicates contamination which can be detrimental to the finished beer. lab, among beer-spoilers, have been reported as the most prevalent which has been estimated for 60–70% of all spoilage incidents (jespersen and jakobsen, 1996; iijima et al., 2007; weber et al., 2008; haakensen et al., 2009). despite the low ph, moderate ethanol content and hop antimicrobials present in beer, microorganisms are responsible for most beer defects. however, hygienic conditions should be observed/practiced to minimize entry and growth of microbial contaminants throughout the beer-making process and ensure consistent manufacturing of high-quality beer. conclusion in conclusion, results obtained from this study showed rice and local sorghum to be a good raw material for beer production and possible replacement of barley in brewing. the results also indicated the presence bacterial contamination in the beer samples under study and this is due to careless handling of fermentation processes, use of unsterilized equipment, poor storage, non-use of pure strains of brewing yeasts and unhygienic production process. various bacteria identified included lactic acid bacteria such as streptococcus, lactobacillus and micrococcus species with different morphological and microscopic characteristics. the prevalence of bacteria species in this study justifies a basic requirement for use of a single strain of microorganisms (pure yeast culture) in fermentation industry to produce desirable products. good and adequate storage facility should be provided mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset during and after fermentation of beer. using a pure culture of yeast strain is recommended for fermentation. sterilized equipment should be used during beer production. good and hygienic manufacturing practices should be maintained while producing beer. further studies should be carried out towards harnessing these bacteria species for a better purpose and also to see if they can be genetically modified to make them suitable for beer fermentation and production of useful metabolites. references agu, r.c and obanu, z.a. (2000). studies on beer production from nigeria sorghum. journal of food science and technology, 28:81-83. agu, r.c. (2006). comparative study of experimental beers brewed from millet, sorghum and barley malts. process biochemistry, 30(4): 311-315. anli, e. and alkis, i.m. (2010). ochratoxin a and brewing technology. journal of institute of brewing, 116(1): 23–32. asano, s., iijima, k., suzuki, k., motoyama, y., ogata, t. and kitagawa, y. (2009). rapid detection and identification of beer-spoilage lactic acid bacteria by micro-colony method. journal of bioscience and bioengineering, 22: 124-229. asano, s., suzuki, k., iijima, k., motoyama, y., kuriyama, h. and kitagawa, y. (2007). effects of morphological changes in beer-spoilage lactic acid bacteria on membrane filtration in breweries. journal of bioscience and bioengineering, 4: 334-338. bischoff, k.m., liu, s., leathers, t.d., worthington, r.e. and rich, j.o. (2009). modeling bacterial contamination of fuel ethanol fermentation. biotechnology and bioengineering, 103(1): 117-122. condina, m.r., dilmetz, b.a., bazaz, s.r., meneses, j., warkiani, m.e. and hoffmann, p. (2019). rapid separation and identification of beer spoilage bacteria by inertial microfluidics and maldi-tof mass spectrometry. the royal society of chemistry, 19: 1961–1970 haakensen, m., schubert, a. and ziola, b. (2009). broth and agar hop-gradient plates used to evaluate the beerspoilage potential of lactobacillus and pediococcus isolates. international journal of food microbiology, 130: 56–60. iijima, k., suzuki, k., asano, s., kuriyama, h. and kitagawa, y. (2007). isolation and identification of potential beer-spoilage pediococcus inopinatus and beer-spoilage lactobacillus backi strains carrying the hora and horc gene clusters. journal of institute of brewing, 113(1): 96–101. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 4; july-august 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset jespersen, l. and jakobsen, 1 m. (1996). specific spoilage organisms in breweries and laboratory media for their detection. international journal of food microbiology, 33: 139-155. lyumugabe, f., gros, j., nzungize, j., bajyana, e. and thonart, p. (2012). characteristics of african traditional beers brewed with sorghum malt: a review. biotechnology, agronomy, society and environment, 16(4): 509-530. lyumugabe, f., gros, j., songa, e. b. and thonart, p. (2015). sorghum beer brewing using eleusine coracana “finger millet” to improve the saccharification. american journal of food technology, 10: 167-175. march, c.j., manclu´s, j., abad, a., navarro, a. and montoya, a. (2005). rapid detection and counting of viable beer-spoilage lactic acid bacteria using a monoclonal chemiluminescence enzyme immunoassay and a ccd camera. journal of immunological methods, 303: 92–104. shabani, l. and devolli, a. (2010). microbial spoilage in beer processing by biofilms. natura montenegrina, 9(3): 655-662. sohrabvandi, s., mousavi, s.m., razavi, s.h., mortazavian, a.m. and rezaei, k. (2010). alcohol-free beer: methods of production, sensorial defects, and healthful effects. food reviews international, 26(4): 335352. suzuki, k., asano, s., iijima, k. and kitamoto, k. (2008). sake and beer spoilage lactic acid bacteria. journal of the institute of brewing, 114(3): 209–223. suzuki, k., iijima, k., sakamoto, k., sami, m. and yamashita, h. (2006). a review of hop resistance in beer spoilage lactic acid bacteria. journal of the institute of brewing, 112(2): 173-191. vaughan, a., o‟sullivan, t. and van sinderen, d. (2005). enhancing the microbiological stability of malt and beer. journal of the institute of brewing, 111(4): 355–371 weber, d.g., sahm, k., polen, t., wendisch, v.f. and antranikian, g. (2008). oligonucleotide microarrays for the detection and identification of viable beer spoilage bacteria. journal of applied microbiology, 105: 951-962. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset empowering educators: integrating climate change education into teacher training programs chika nwachukwu okonkwo educational foundations, university of port harcourt, nigeria abstract climate change poses a severe threat to the planet, and addressing it requires immediate attention. this study examines the causes and impacts of climate change while emphasizing the crucial role of teacher preparation in addressing this global challenge. education is a powerful tool that can either contribute to positive change or perpetuate the status quo, depending on the quality of education provided and the effectiveness of teachers. the paper contends that mitigating the climate change crisis, along with environmental pollution, can be achieved by producing highly motivated, conscientious, and competent teachers across all levels of education. keywords: climate change, environmental pollution, teacher preparation, education, global warming. introduction the fragile nature of our earth today as a result of climate change is a serious threat to human lives. global warming, pollution, environmental degradation emanating from climate change, are most dangerous issues that deserve urgent attention. the study focuses on climate change, its causes, the dangers or impact of the change and appropriate teacher preparation. education is a most powerful weapon for change and direction. ukeje (2000) cited in anekwe and okoli (2011) noted, it is so powerful that it can heal/ kill; it can build up or tear down. but it depends on the type of education provided and particularly the teacher who is the pillar of the education process. the paper argues that the present crisis of climate change and environmental pollution could be cushioned according to npe (2004) by raising highly motivated, conscientious and efficient classroom teachers for all levels of our educational system. the study focuses on the university where trained teachers with curriculum in climate change through constant research and update could bring awareness and means of ameliorating and eliminating causes and problems attendant to climate change. understanding climate change climate change has to do with a change of climate which is attributed directly or indirectly to natural and human activities that alter the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time period s. it refers to changes and challenges that have adversely affected human race generally. oxford dictionary sees climate change as change in global or regional climate pattern, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased level of the atmospheric carbon-dioxide(co2) produced by the use of fuel fossils. in this definition, climate change is a threat to human lives because of excess co2 release into the atmosphere. the ipcc report (2007) refers to climate change as a change in the state of the climate that can be identified (e.g. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset using statistical tests) by changes in the variability of its properties, and that persists for an extended period, typically decades or longer. it refers to any change in climate over time whether due to natural variability or as a result of human activity. mkpa (2013) noted that un framework convention (unfccc) refers to climate change as a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time period. wikipedia (2010) pointed out that climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. it may be change in average weather conditions that is extreme weather events. unesco (2009) noted that it could be conceived as a change in the statistical properties of the climate system when considered over a long period of time regardless of cause. it is noted that climate change is the biggest environmental and humanitarian threat in the world today. the change makes the earth’s atmosphere overloaded with heat-trapping co2 which threatens large scale disruptions in climate giving rise to global warming which is a most serious threat to life. climate change may occur in a specific region or across the globe. this anthropogenic climate change is called anthropogenic global warming. the causes of climate change are varied. greenhouse gases co2 and other pollutants methane, nitrous oxide are colliding in the atmosphere like a thickening blanket trapping the sun’s heat and causing the planet to warm up (wwwntdc.org/global warming). these gases absorb infrared radiation of heat and cause the warming up of the planet. why climate change? climate change, otherwise global warming, is caused by human activities. international government panel on climate change (2007) reported that in the past 100 years, global surface temperature has increased on the average of 0.6 0c. central to climate change is pollution which involves the emission of harmful substances into the air, land and water. although pollutions have been occurring throughout history, the rate at which human beings have contributed to the amount of pollution that has entered our environment over the past 100 years far exceeds the earth’s inherent ability to heal itself. some of the activities of humans that lend breath to global warming are as follows: greenhouse gases there are several greenhouse gases that are responsible for global warming and human beings emit them in variety of ways. most come from combustion of fossils fuels in cars, factories, and electricity products. the gas responsible for most warming is carbon dioxide (co2), others are methane, released from landfills and agriculture especially from digestive systems of grazing animals and nitrous oxide, from fertilizers, gases used for refrigerators and industrial processes. categories of greenhouses have heat-trapping abilities. some of them can trap more heat than co2. usa environmental protection agency (epa 2014) pointed out that the heat absorbed by the planet is sometimes released as infrared radiationgreenhouse gases (gh4) like water vapour (h20), carbon dioxide (co2) and methane (ch4) absorbed energy, slowing or preventing the loss of heat to space. ghgs act like blanket making earth warmer than it should be. natural causes mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset global warming occurs through natural phenomena like solar variations, volcanic eruptions, glacier melting, and ocean currents orbital variations, etc. variations in solar intensity affect global climate, and accumulation of the intensity gives rise to overheat that is detrimental to life and health. volcanic eruptions cause the release of large quantities of sulphur dioxide (so2), water vapour, ash or dust. the reflection of solar energy on the space brings cooling effect that produces green house gas, co2 oceanic currents hays et al. (2005) noted that ocean currents are major drivers of global climate. through environmental forcing mechanism redistributes heat around the planet. the huge amount of currents derived from ocean movement constitutes climate system. these produce topography affecting climate, atmospheric and ocean circulation. changes in ocean circulation give rise to co2 movement into the atmosphere. increased and unrelenting hurricanes, tornadoes, earth tremors, flooding and general increase in water levels, heavy rain falls, drought, promote climate change. human activities the contribution of human beings to climate change has been enormous. mkpa (2013) noted that various types of combustion-gas flaring by oil companies, burning of household waste, industrial pollution of smoke and gases, bonfires etc produce carbon compounds that destroy the ozone layer. electric power plants emit billion tons of co2, this constitutes 40% emission. agricultural activities of bush burning, use of insecticides, deforestation, fishermen’s use of chemicals for fishing, explosives, all kinds of cigarettes, weeds, pipesmoking, smokes from exhaust pipes, produce carbon compounds and other green house gases. breeding of cattle and cutting down forests, lend weight to climate change. industrialised nations have also been breeding vast number of methane-producing livestock and cutting down forests that naturally absorb co2 from the air. compassion in world farmageddon (2014) noted that agricultural activity like factory farming is a dangerous, unfair activity with impacts ranging from climate change to biodiversity loss and disease to food insecurity. beyond these, the researcher observed that in nigeria, long hours of hold up cause release of co2 fumes from vehicles’ exhaust pipes. the terrible bad roads make driving difficult and long lasting than usual. thus there is an unending pollution of the environment. many deaths are witnessed in nigeria and all these pollutions contribute to it. cattle graze along the high ways with their droppings everywhere. their purification constitutes pollution because co2 is released in large quantities. oil pollution is a common feature in nigeria as witnessed in the oil producing areas. the damaging effect on plant life and environment are terrible. trapped co2 discharge of wastes into streams and rivers affects the water bodies and shifts in the ecosystem balance. salinisation of fresh water causes acidity concentration in waters as more co2 dissolve in them. impact of climate change the impact of climate change is enormous. dunnell et al. (2011) noted that regional temperature increases over the past 100 years are caused by increasing concentrations of green house gases in the temperature which trap reflected radiation. ipcc (2007) noted that the rate of global warming from 1976 onwards has been greater than in the past 100 years. continuous increase in concentrated atmospheric co2 has been recorded. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset it is changing our economy, health, communities in diverse ways. the earth heats up and there are drought, storms and fire. 2012 weather report showed that waves, wildfires, floods, drought hit hard in the year. global warming has given rise to shortage of water supply for communities. it is a threat to the elderly, children and those living in poverty and want. www.nrdc.org/global warming. mkpa (2013) enumerated the impact of climate change. it has devastating effect on homes. communities had been flooded out leading to displacement, loss of lives and property and washing off of coastlines. natural resource has been reduced introducing famine and hunger. it has led to insecurity and exposure to danger. increase in extreme weather and sunshine give rise to heat scourge on humans and animals. the impact of pollution, dirty surrounding has given rise to all kinds of respiratory infectious diseases. the impact is overwhelming. it therefore calls for awareness and serious dissemination of knowledge. climate change curriculum the need for education and integration of climate change into school curriculum is most urgent. curriculum is the focus of all school activities and it speaks volumes in terms of assessing a nation’s educational system. curriculum in a formal school setting is a set of learning experiences organised through the teaching of patterned and integrated courses and their contents offered at a school or university. padsham et al. (2009) noted that a wellinformed citizenry, responsive institution and problem focused knowledge generation are key elements for effectively addressing challenges emerging from climate change. the university has a vital role to play in strengthening knowledge systems. chakeredza et al, (2009) noted that issues of climate change should be infused into curricular of universities as a matter of urgency. the growing need for evidence based scientific data on african experiences to be infused into the curricula to serve the african specific problems is overdue. africa and nigeria in particular has to make significant and well-targeted investment in education and training, curriculum development, research and effective practices for communication of research findings. such investments would yield dividends when carried out around climate change. the darressalaam (2010) forum on education, capacity building and climate change curriculum and strategy for collective action in africa met to articulate a vision and to develop a strategy for developing appropriate curricula on climate change, to reinvigorate teaching in order to better address climate change issues, to cultivate demand for climate change course and to bring existing courses to include issues of climate change and to put in place certain professional training modules. thus curriculum for climate change will lead students to a progression of understanding of how humans cause climate change, the impact of greenhouses and the action necessary. school (teacher) plays a major role in the education of future consumers and demands made. getting students understand climate change, its impact and solution prepares them to play active role in making good choice for both society and environment. okey and ndum (2013) pointed out that the curricula could be handled as a separate subject or infused and integrated into the existing courses. the methodology for teaching and learning should be lectures, seminars, group discussions, visits to sites demonstrating the impact of climate change and adaptation and mitigation work in progress, on-farm discussions and surveys. e-learning enhanced with research repositories can also be pursued where practicable. suggested topics for climate change curriculum mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in keeping with mkpa 2013, osaat 2013, and compassion in world farmaggeddon 2014, three distinct areas are here proposed environmental education, ecosystem education, and environmental science education. the areas could be split into sub-sections as follows: 1. under environmental education will be considered natural environment function, human management, settlements development and urbanisation. 2) under eco-system education will be considered bio diversity, conservation biology and all aspects of the eco-system 3) environmental science education will cover physical, biological & information science and solution to environmental problems. other areas could be included with time. university education and teacher preparation university education is the highest level of education in nigeria. with the establishment of over one hundred and twenty nine universities, there is no gainsaying that the nation needs to take up the challenge of training qualified teachers, at this highest level, who would be equipped to put into action, climate change curriculum at the other levels of education. goals of university education universities have the special responsibility for generating and diffusing knowledge into the economy and creating opportunities for innovation. a university trained teacher should therefore be able to perform in line with the laid down policies in education. the npe (fgn 2004:25) noted that university should intensify and diversity its programmes for the development of high level manpower within the context of the needs of the nation. obanya (2004) noted that education should equip people with the knowledge and skills needed to live in a high tech world. university should be able to produce highly talented teachers that would alert people of the dangers inherent in the methods of interaction with the environment and how to take preventive measures. universities are centres of excellence, transdisciplinary, and shared thinking and intellectual domain. they are custodians of knowledge; they provide avenues for transdisciplinary, multidisciplinary and shared thought that could sustain the socioeconomic and environmental growth and development of any nation. universities are best positioned to accommodate climate change which requires knowledge across disciplines to provide strategies for mitigation and adaptation. the university offers the most appropriate opportunity for capacity building, that is for the training of teachers and and empowering the youth, the future leaders of tomorrow who with their training will be environmentally responsible. mohanan (2010) noted that the goals of a university education have four interlocking goals, as follows: a) dissemination of knowledge (knowledge of older generation preserved for new generation) b) training people aimed at the production of man power needed for the preservation and progress of the nation and society (teachers, engineers, architects, bankers, farmers etc) c) training of researchers needed for the preservation and expansion of human knowledge d) development and enhancement of the inner potential of individual (intellectual, moral physical, spiritual, social etc. and in addition community service. necessity for teacher preparation for climate change curriculum mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset teacher preparation at the university level is most appropriate for teaching functions. the teacher through various functions is equipped to effectively handle climate change curriculum. the university trained teacher, teaches, disseminates knowledge, research findings to government and industries and development and enhancement of potentials. dissemination of knowledge and community service the trained and qualified teacher for climate change must be prepared to disseminate knowledge, information and ideas relating to climate change and environmental education. he should be able to disseminate knowledge on how to handle environmental problems as a result of man encroachment on the land through use of modern equipment and industrial activities. the trained teachers should create fora for interaction with students and community members and integrate needs into research and teaching. capacity building the teacher should be able to train and produce in turn capable manpower that would sustain the work initiated and for the sustenance, progress and preservation of the nation and society. the teacher is able to produce engineers, bankers, and architects etc who have been exposed to climate change education. teaching the trained teacher should be prepared to interact with learners with the aim to help them acquire and sustain knowledge, skills, ideas etc teaching aims at inculcating into the individual the power of acquisition, synthesis, retention, evaluation and development of habits attitudes necessary for effective learning, the teacher in this way will help learners acquire knowledge, ideas and how to tackle climate change and all the attendant problems. a teacher on climate change should be conversant with global trends, vision and occurrences in matters of university education curricula with a view of infusing generic skills that would equip the students for the world of work. obanya (2003:139) aptly articulated necessary generic skills for the teacher some of which are pointed out here. analytical power, that is, an advanced capacity for logical reasoning, verbal, expression and power of perceptions etc; communication, power of oral and written expressions, problem solving, that is the ability to task one’s analytical power to the maximum in a wide variety of situations; team spirit, the ability to contribute meaning fully in group activity in a wide variety of forms , to relate to others, to get out of one’s shell while remaining oneself; creativity, the ability to go beyond the welltrodden path, in thinking as well as action. versatility is necessary, that is a broadened horizon in terms of domains of knowledge and competence. lifelong learning skills: perseverance, risk-taking and enquiring, reading as a habit, selfdirected learning efforts, and the ability to face challenges, etc. information technology (it): as a discipline in its own right, as a tool for support to other disciplines and life activities. the climate change curriculum trained teacher needs acquire the above generic skills to pass on to students and others. these skills are so relevant and necessary for our educational system today. research it is a norm that the trained teacher has been equipped to understudy research into issues and challenges of climate change and all other aspects. the teacher through seminars, awareness campaigns and personal contact should interact with all groups in the society. for instance his wealth of knowledge and experience, findings mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and methods should rub off on other researchers, farmers, individuals and communities. he should be prepared to be a collaborator and consultant for non government organizations, for government, individuals etc he needs to engage in continuous research exercise that must be sustained through development of learning skills. research results that would enable the society tackle climate change challenges. conclusion human activities in agriculture and industries have been identified as being responsible for climate change with terrible and life-threatening consequences. the need for proper curriculum and training of teachers at the university level for awareness will go a long way in helping to cushion problems of climate change and the need for a healthier society. recommendations high-powered awareness campaign through a strong workforce and research should be mounted at all levels of government. universities in addition to raising strong work force should embark on research with search light on all aspects of climate change. the society as a whole through awareness should participate in tackling the challenges references chakeredza, s., temu, a., yaye, a., mukingwa, s. and saka, k. (2009). mainstreaming climate change into agricultural education: challenges and perspectives. icraf working paper no. 82. nairobi kenya: world agro forestry centre. debating policy options for national development : enugu forum policy developing paper10; african institute for applied economics(aiae);enugu,nigeria.http://www.aiaenigeria.or/publications/policypaper10.pdf/10/09/2 012 compassion in world farmageddon (2014). www.ciiwfiorg.uk/ourcompany farmageddon dunnell, k. and travers, s(2011). shift in the flowering phenology of northen green plants https://www.google.com.ng/webhp?sourceidion pcc (2007). inter-governmental panel on climate change. impacts, adaptation and vunerability. cambridge university press hays, g.c., richardson, a.j. and robinson, c.(2005). trends in ecology and evolution.centre for ocean solution.org/climate impacts/ocean milakovitch cycles and glaciations (2009). university of montana http://www.hompage.montana.edu mkpa , m .(2013). development of curriculum on climate change for non-formal education. journal of curriculum studies vol. 20 no 4. mailto:topacademicjournals@gmail.com http://www.aiaenigeria.or/publications/policypaper10.%09pdf/10/09/2012 http://www.aiaenigeria.or/publications/policypaper10.%09pdf/10/09/2012 http://www.aiaenigeria.or/publications/policypaper10.%09pdf/10/09/2012 http://www.hompage.montana.edu/ http://www.hompage.montana.edu/ academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mohanan,k.p.(2010). the goals of education.https://www.google.com.ng/webhp?sourceid chromeinstantq/or obanya, p. (2003). revitalising education in africa. lagos : stirling-horden publishers obanya, p (2004).the dilemma of education in africa. heinemann educational books (nigeria) okey, s. and ndum, v. e. (2013). curriculum development on climate change in nigerian university system challenges and solutions. nigerian journal of curriculum studies. vol. 20, no. 3. osaat, s. d. (2013).teacher preparation and climate change curriculum at higher education in nigeria. paper presented at teacher preparation and climate change curriculum conference at the university of port harcourt, october, 12-13, padsham, j., virji, h. and seipt, c., (2009). curriculum for climate change www.sciencedirect.com/sc/article/pii/s22 ukeje, b.o. (2000). teacher education in nigeria. in anekwe j.u. and okoli, n.j. (2011). teacher education for the future: focus on nigeria. trends in educational studies (tres) journal of the institute of education, university of port harcourt. vol.6 numbers 1 & 2 april & november, 2011 unesco, (2010) wikipedia, (2009).available-http://simple.wikipedia.org/wiki. mailto:topacademicjournals@gmail.com http://www.sciencedirect.com/sc/article/pii/s22 http://www.sciencedirect.com/sc/article/pii/s22 academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset measuring work engagement in the nigerian context: utrecht scale adaptation" prof. emmanuel okoye department of psychology federal university, ndufu-alike nigeria abstract the prevailing perception of psychology, particularly occupational health psychology (ohp), has historically centered on addressing negative aspects of human behavior and well-being. this skewed focus on pathology and dysfunction has led to an imbalance in research, with a significantly greater emphasis on negative states compared to positive ones. for instance, the ratio of research on negative states to positive states was estimated at 14:1, indicating a disproportionate emphasis on the former. this imbalance is also evident in ohp, where approximately 94% of research has concentrated on the negative aspects of worker health and well-being, with only around 5% addressing positive aspects. this heavy focus on negatives has limited the development of new methods and strategies for enhancing organizational effectiveness. recognizing the need for a shift in perspective, researchers have emphasized positive organizational behavior (pob) as a crucial area of study. pob focuses on harnessing human resource strengths and psychological capacities to improve workplace performance effectively. this approach aligns with the emerging field of positive psychology, which seeks to scientifically examine human strengths and optimal functioning. this transformation in perspective is beginning to address the historical imbalance and offers new insights into how organizations can leverage positive aspects of human behavior and well-being for improved productivity and effectiveness. keywords: psychology, occupational health psychology (ohp), positive psychology, positive organizational behavior (pob), well-being. introduction since antiquity psychology, especially occupational health psychology (ohp) focused on negative aspects of human behaviour such as malfunctioning, weakness and pathology (schaufeli & salanova, 2007). even to a lay person, psychology literarily means repairing or healing the mentally sick or individuals with emotional problems. this prevailing negative preconception of psychology is illustrated by the fact that the number of researches on negative states outweighs that on positive states by a ratio of 14:1 (myers, 2000). an earlier estimation of diener, suh, lucas and smith (1999) revealed a poorer ratio of 17:1. similarly, bakker and schaufeli (2001) observed that about 94% of all researches that have been conducted so far in ohp focused on the negative aspects of worker’s health and well-being. in contrast, only about 5% deals with positive aspects. this seems to have affected productivity in organisations, in that hardly have any new means or mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset methods of improving organisational effectiveness been identified. this may be the reason bakker and schaufeli (2008) emphasised the need for positive organisational behaviour (pob) research, which is defined as the study and application of positive-oriented human resource strengths and psychological capacities that can be measured, developed, and effectively managed for performance improvement in today’s workplace (luthans, 2002). however, there seems to be a transformation because since the beginning of this century, more attention is being paid to what has come to be known as positive psychology: the scientific study of human strength and optimal functioning (seligman & csiksentmihalyi, 2000). this approach is considered to supplement the traditional focus of psychology on disease model not to replace it (seligman, 1998). this recent trend to concentrate on optimal functioning also aroused attention in organisational psychology (luthans, 2002; luthans & youssef, 2007). this trend towards positive psychology has led to the emergence of the concept of work engagement. work engagement has continued to attract research attention within the scientific community. the current study is about the psychometric evaluation of the nigerian version of a self-report questionnaire to assess work engagement the utrecht work engagement scale (uwes-n). this study is pertinent because increasing job insecurity engendered by social and economic pressures seem to have caused many employees to be disengaged in their work. as a result, the study of work engagement has become a vital area in organisational and social psychology in many countries including nigeria. nigeria’s emergence from a traditional agro-based society to a somewhat industrial society with increasing growth and spread of formal organisation makes the study of work engagement even more imperative. as in many other countries that have embraced the construct, work engagement is potentially fruitful for the study and practice of well-being of nigerian workers. so in order to study and to maximize the concept of work engagement in nigeria, the adaptation of the uwes should be the first step. conceptualisation and definition of work engagement work engagement was conceptualised by khan (1990) as the harnessing of organisational members’ selves to their work roles where people employ and express themselves physically, cognitively and emotionally during role performances. work engagement is the assumed opposite of burnout. in fact, it is research on burnout that stimulated studies on its presumed opposite: work engagement. maslach and leiter (1997) suggest that burnout and engagement are two opposite poles of one continuum and rephrased burnout as an erosion of engagement with the job, whereby energy turns into exhaustion, involvement turns into cynicism, and efficacy turns into ineffectiveness. according to maslach and leiter, engagement is characterised by energy, involvement and professional efficacy, which are perfectly and inversely related to the three burnout dimensions. work engagement is defined as “a positive, fulfilling, work-related state of mind that is characterised by vigour, dedication, and absorption” (schaufeli, salanova, gonzalez-romá, & bakker, 2002, p. 74). according to them, work engaged individuals are full of vitality, they feel they are glued to their work, and are better able to deal with job demands (schaufeli & salanova, 2007). engagement is neither a momentary nor a specific state, but refers to a more persistent and pervasive affective-cognitive state that is not focused on any particular object, event, individual, or behaviour (shimazu, et al., 2008). vigour is characterized by high energy levels and mental resilience while working. dedication refers to being strongly involved in one’s work mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and experiencing a sense of significance, enthusiasm, and challenge. absorption entails being fully concentrated and happily engulfed in one’s work, whereby time passes quickly and one has difficulties with separating oneself from work (schaufeli & bakker, 2004). in short, engaged employees have high levels of energy and are enthusiastic about their work, they are often fully immersed in their work so that time flies (may, gilson, & harter, 2004). the experiences of time passing quickly and forgetting everything around one are evidence of the absorption dimension (schaufeli & bakker, 2001). the current study adopts schaufeli et al’s. (2002) definition of work engagement. utrecht work engagement scale (uwes) because of the importance of the work engagement construct, the utrecht work engagement scale (uwes; schaufeli, et al., 2003) was developed to measure the underlying dimensions of work engagement including vigour, dedication, and absorption. uwes is available in 17 languages (schaufeli & salanova, 2007) and have been psychometrically evaluated in over ten countries including china (yi-wen & yi-qun, 2005), finland (hakanen, 2002), greece (xanthopoulou, bakker, demerouti, & kantas, 2007), south africa (storm & rothmann, 2003), spain (schaufeli, et al., 2002), and the netherlands (schaufeli & bakker, 2003; schaufeli, et al., 2002), japan (shimazu, et al., 2008). in most of these countries, the factor validity studies show that scores on the uwes are best represented by three factors (e.g., schaufeli, bakker, & salanova, 2006); however, not all items are invariant across countries (schaufeli, et al., 2006). due to the fact that uwes has been validated across many cultures, researchers (e.g., storm & rothmann, 2003) have acknowledged that it can be used as an unbiased instrument to assess work engagement because the three-factor model has proven cross-national validity. despite this global recognition and acceptance of the potency of the uwes structure and its psychometric values the relevance of the scale has not been ascertained in nigeria. uwes development and initial validation the uwes has initial item pool of 24, but after psychometric evaluation, 7 unstable items were eliminated so that 17 items remained (schaufeli, et al., 2002). it is a self-report instrument that includes the three dimensions: vigour, dedication and absorption. the original uwes (uwes-17) includes 17 items (schaufeli, et al., 2002): vigour (6 items), dedication (5 items), and absorption (6 items). the uwes-17 has encouraging psychometric features (schaufeli, et al., 2006). more specifically, the internal consistencies (cronbach’s alpha) of the scale range between .80 and .90 (durán, extremera, & rey, 2004; schaufeli & bakker, 2004). thus, values of cronbach’s alpha exceed the value of .70 that is traditionally used as a rule of thumb (nunnally & bernstein, 1994). statement of the problem the psychometric properties of the uwes (schaufeli & bakker, 2003) have been assessed by different researchers and in diverse countries since the scale’s development. the initial problem is that while uwes responses have been studied in many countries, there has been no investigation of its structural validity and reliability in a nigerian sample. furthermore, it has been demonstrated that uwes items are not constant across countries. this is problematic because the scale has continued to gain popularity among nigerian researchers, thus making it imperative to examine the dimensionality and reliability of uwes responses in mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset nigeria. besides, there are ample research opportunities on work engagement in nigeria as an emerging economy and adapting the scale for nigeria would stimulate research in this direction. research questions the current study attempted to provide answers to the following five research questions: 1. what are the underlying factors of the uwes-17 items in a nigerian sample? 2. what are the internal consistency reliability estimates of the uwes dimensions? 3. does work engagement differ with age? 4. is there significant gender difference in response to the work engagement scale? 5. does work engagement differ between occupational groups in nigeria? method samples and procedure participants in this study were nigerian employees drawn from across two occupational groups: banking sector and employees in a production company in nsukka, south-east nigeria. a total of 268 employees completed the questionnaire (mean age = 33.7, sd = 8.3). their ages ranged from 23 to 51 years. demographic information was collected from participants including gender, marital status, education, employment status, job tenure, and organisational tenure. table 1 presents the demographic characteristics of participants. table 1: demographic characteristics of participants variables levels no. (%) gender male 197 (73.51%) female 71 (26.49%) age young 146 (54.48%) old 122 (45.52%) marital status married 177 (66.04%) single 91 (33.96%) education secondary school graduate 47 (17.54%) university graduate 163 (60.82%) postgraduate 28 (21.64%) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset employment status full time 203 (75.75%) part time 65 (24.25%) job tenure short tenure 151 (56.34%) long tenure 69 (43.66%) organisational tenure short tenure 197 (73.51%) long tenure 71 (26.49%) in order to adapt the uwes-17 for nigerian samples, it was first subjected to face and content validity and reliability tests. the 17-item scale was presented to eight experts; four from the management and four from psychology. they included four industrial/organisational (i/o) psychologists and three regional heads of human resource (hr) units of three banks and one from a production company. those from the management were asked to verify whether the items in the scale actually represent what is ordinarily regarded as work engagement in their respective organisations, while the i/o psychologists were, on the other hand, requested to identify which items they think do not measure the three dimensions of engagement as was operationally defined in the study. there was 100% agreement among the experts that all the items have face and content validity. a total of 305 employees received the survey in their places of work, but out of this number only 297 copies of the scale were adequately completed and returned, representing a response rate of 97.38%. out of this number also, 29 (9.76%) copies were not usable and only 268 (90.24%) copies were subjected to analyses. instrument work engagement was measured with a preliminary nigerian version of the uwes (uwesn) that was originally developed by schaufeli et al. (2002). the items of the uwes are grouped into three subscales that reflect the underlying dimensions of engagement: vigour (six items), dedication (five items), and absorption (six items). all items are scored on a 7point likert scale ranging from 0 (“never”) to 6 (“always”). completion and scoring of uwes the uwes can be administered individually or in group and it takes about 5-10 minutes to complete the scale (schaufeli, et al., 2002). the uwes may be used for individual as well as for group assessment. for instance, it could be used as part of an employee satisfaction survey, or a psychosocial risk evaluation (schaufeli, et al., 2003). it is recommended that the test takers be made to clearly understand the process involved in completing the scale before they respond to the items. in order to reduce response biases (social desirability) or the ones that might result from specific connotations related to ‘work engagement’ this term, that is, work engagement is not used in the title of the scale. a more neutral term ‘work & well-being survey’ is chosen instead, with uwes in parentheses (schaufeli, et al., 2002). the mean score of the three uwes subscales is the bases for interpreting the scores of respondents. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset this is achieved by adding the scores on the particular scale or subscale and dividing the sum by the number of items of the scale or subscale. hence, the uwes, yields three subscale scores and/or a total score that range between 0 and 6 that totals 102 for the full version and 54 for the short version. results this section reports outcome of the analyses of psychometric properties of the uwes in a nigerian sample. the results of the descriptive statistics are provided, followed by the results of the five research questions postulated in the study. descriptive statistics table 1: mean and standard deviation scores of age on work engagement scale age mean (m) std. deviation number young 58.13 10.82 146 old 58.24 10.33 122 total 59.07 9.73 268 table 2: mean and standard deviation scale scores of female and male on work engagement gender mean (m) std. deviation number female 57.52 10.71 101 male 59.07 10.41 167 total 58.09 10.26 268 table 3: mean and standard deviation scores of occupational groups (banking & production) on work engagement scale. organisation mean (m) std. deviation number banking 58.62 9.94 179 production 57.49 11.53 89 total 58.17 10.58 268 the descriptive statistics computed shows that older respondents reported slightly higher mean score on work engagement scale (m = 58.24, sd = 10.33) compared to the younger respondents (m = 58.13, sd = 10.82) (see table1). the results equally indicated that male respondents reported slightly higher mean score on work engagement scale (m = 59.07, sd = 10.41) compared to their female counterparts (m = 57.52, sd = 10.71) (see table 2). the result further revealed that respondents from the banking sector reported higher mean score on work engagement scale (m = 58.62, sd = 9.94) compared to their counterparts from the production sector mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (m = 57.49, sd = 11.53) (see table 3). results of test of significance of the means are reported in table 4 below. table 4: three-way anova summary table showing the reports of age, gender and occupational group differences on work engagement scale. source sum of square df mean square f age (a) 99.34 1 99.34 .88 gender (b) 415.06 1 415.06 3.70* occupation (c) 6.64 1 6.64 .06 a x b 20.58 1 20.58 .18 a x c 282.00 1 282.00 2.52 b x c 364.20 1 364.20 3.25 a x b x c 61.02 1 61.02 .55 error 17930.15 260 112.06 total 18697.99 267 note: * p < 0.05 a further test of significance, utilizing analysis of variance (anova) showed that it was only gender that showed a significant difference in response to work engagement scale. age showed no significant difference. with regards to the two occupational groups surveyed in the study, the anova test did not also reveal any significant differences in their response to work engagement scale, that is, between workers from the banking sector and their counterparts from the production sector. however, the first research question that hinged on the underlying factor of the uwes-17 items in a nigerian sample was addressed by computing an exploratory factor analysis using varimax rotation with kaiser normalisation method. following these analyses, the second research question was addressed by examining the internal consistency of uwes-17 scores. validity and reliability of uwes-n the result of the item analysis computed revealed that the item-total correlations ranged from .38 to .68. for the individual scales, vigour dimension has a cronbach’s α of .73; dedication has .79, and absorption has .70. the 17 items cumulatively yielded a cronbach’s α of .85 against a cronbach’s α of .93 observed by schaufeli and bakker (2003). the observed difference in the reliability index might have resulted from the sample size used. while the original version used a sample size of 9,679, the present study utilised only 268 participants mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (see appendix a for the inter-item correlation). a test-retest reliability coefficient of .77 after three weeks interval was also obtained. this agrees with earlier studies (e.g., schaufeli, et al., 2006) which asserted that uwes-17 has acceptable psychometric properties. an exploratory factor analysis was performed on the uwes-17 using the principal components factor analysis to ascertain whether the three-factor structure of uwes would hold. in the first analysis, four factors emerged, which almost loaded strongly in the factors, but when the varimax rotation with kaiser normalization analysis was performed on the data, a three clear factor model emerged (see appendix b). based on the above finding, work engagement is perceived as a three-factor model in nigeria representing employee behaviour in the performance of their job. this is consistent with earlier studies on uwes (e.g., demerouti, et al., 2001; schaufeli, et al., 2002). it also concurs with seppala et al. (2008) whose factor analyses supported the hypothesised correlated three-factor structure. towards a short measure of work engagement besides the uwes-17, a shortened version of 9 items (the uwes-9) has long been advocated. for example, schaufeli, bakker and salanova (2006) utilised data from 10 different countries (n = 14,521), and results indicated that the full version of uwes can be shortened to 9 items. the factorial validity of the uwes-9 was demonstrated using confirmatory factor analysis, and the three subscale scores have good internal consistency and test-retest reliability. it has acceptable psychometric values (schaufeli, et al., 2006). also, seppala et al. (2008) utilised five divergent occupational samples (n = 11, 959) and their confirmatory factor analyses supported the hypothesised correlated three-factor structure – vigour, dedication and absorption of the uwes scale. seppala et al. reported that while the structure of the full version did not remain the same across the samples and time, the structure of the uwes-9 remained relatively stable. the uwes-9 has good construct validity and the use of the 9-item version can be recommended in future research (seppala, et al., 2008). despite having used data from numerous countries to test the consistency of uwes-9, its psychometric properties are yet to be examined in a nigerian sample. in order to adapt the uwes-9 for nigerian samples, it was subjected to reliability test. the result of the reliability test that was run on uwes-9 using 268 respondents, the same as on the uwes-17 showed that the item-total correlations ranged from .41 to .66 (see appendix c for the inter-item correlation). for the individual scales, vigour dimension has a cronbach’s α of .76; dedication has .79, and absorption has .74. the 9 items yielded a cronbach’s α of .91. a test-retest reliability coefficient of .87 after three weeks interval was also obtained. this agrees with earlier studies (e.g., schaufeli, et al., 2006; seppala, et al., 2008) which asserted that uwes-9 has acceptable psychometric properties. also, an exploratory factor analysis was performed on the uwes-9 using the principal components factor analysis to ascertain whether the three-factor structure of uwes would still hold and it did (see appendix d). discussion and conclusion the current study confirmed that the uwes-n, both the full version (uwes-17) and the shortened version (uwes-9) are adequate measures of work engagement that can be used in the nigerian context. this is based on the fact that the uwes has quite satisfactory psychometric properties: 1. the three subscales are internally consistent; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. the three-factor structure was confirmed; 3. age was not statistically significant in responses to the work engagement scale; 4. males reported slightly higher work engagement scores than their female counterparts; 5. there was no statistically significant difference between the two occupational groups tested in their responses to the work engagement scale. the researcher expect that the adaptation of this scale will stimulate interest not only for further studies or theorising on work engagement in nigeria, but also as a tool for organisational practitioners as it relates to positive organisational behaviour. the present study was limited to only two occupational groups; there is the need to extend research on work engagement to other occupational groups by adapting the scale to these groups. the sample size for the present study was small; there is need for an additional sample because this smallness of sample size may have given rise to sampling error. based on findings from the current study, recommendations for further investigation have been offered. although the current study supported a three dimensional structure of uwes, the question still remains whether this three-dimensional structure are stable over time in a nigerian sample. therefore, future research should attempt to confirm the factor structure of work engagement longitudinally in nigeria. whether there are different antecedents and consequences of each of the dimensions is still vague; further research is needed for clarity. this is important because since the behaviour pattern of these dimensions differs significantly, they could as well have different drivers and outcomes. references bakker, a. b., & schaufeli, w. b. (2001). socially induced burnout. paper presented at the 5th eawop congress. prague, czech republic. bakker, a. b., & schaufeli, w. b. (2008). positive organisational behaviour: engaged employees in flourishing organisations. journal of organisational behavior, 29, 147154. diener, e., suh, e., lucas, r. e., & smith, h. (1999). subjective well-being: three decades of progress. psychological bulletin, 125, 276-302. durán, a., extremera, n., & rey, l. (2004). engagement and burnout: analysing their association patterns. psychological reports, 94, 1050-1084. hakanen, j. j. (2002). validation of the finnish version of an instrument for measuring the job engagement (uwes) in an educational organisation. työ ja ihminen, 16, 42-58. khan, w. a. (1990). psychological conditions of personal engagement and disengagement at work. academy of management journal, 33, 692 –724. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset luthans, f. (2002). the need for and meaning of positive organizational behavior. journal of organizational behavior, 26, 695-706.luthans, f., & youssef, c. m. (2007). emerging positive organizational behavior. journal of management, 33, 321-349. maslach, c., & leiter, m. p. (1997). the truth about burnout: how organizations cause personal stress and what to do about it. san francisco, ca: jossey-bass. may, d. r., gilson, r. l., & harter, l. m. (2004). the psychological conditions of meaningfulness, safety and availability and the engagement of the human spirit at work. journal of occupational and organizational psychology, 77, 11-37. myers, d. g. (2000). the funds, friends and faith of happy people. american psychologist, 55, 56–67. nunnally, j. c., & bernstein, i. h. (1994). psychometric theory (3rd revised edition). new york, ny: mcgraw-hill. schaufeli, w. b. & bakker, a. b. (2001). work and well-being: towards a positive approach in occupational and health psychology. gedrag en organisatie, 14, 229–253. schaufeli, w. b., & bakker, a. b. (2003). utrecht work engagement scale (uwes): test manual. unpublished manuscript. department of psychology, utrecht university, the netherlands. schaufeli, w. b., & bakker, a. b. (2004). utrecht work engagement scale, preliminary manual. occupational health psychology unit, utrecht university. schaufeli, w. b., bakker, a. b., & salanova, m. (2006). the measurement of work engagement with a short questionnaire: a cross-national study. education and psychological measurement, 66, 701-716. schaufeli, w.b., & salanova, m. (2007). work engagement: an emerging psychological concept and its implications for organizations. in s.w. gilliland, d.d. steiner, & d.p. skarlicki (eds.), research in social issues in management (volume 5): managing social and ethical issues in organizations. greenwich, ct: information age publishers. schaufeli, w., salanova, m., gonzalez-roma, v., & bakker, a. (2002). the measurement of engagement and burnout: a two sample confirmatory factor analytic approach. journal of happiness studies, 3, 71-92. seligman, m. e. p., & csikszentmihalyi, m. (2000). positive psychology: an introduction. american psychologist, 55, 5-14. seligman, m. e. p. (1998). positive social science. science and spirit, 9, 6. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset seppälä, p., mauno, s., feldt, t., hakanen, j., kinnunen, u., tolvanen, a., & schaufeli, w. (2008). the construct validity of the utrecht work engagement scale: multisample and longitudinal evidence. journal of happiness studies, 10(4), 459-481. shimazu, a., schaufeli, w. b., kosugi, s., suzuki, a., nashiwa, h., kato, a., sakamoto, m., irimajiri, h., amano, s., hirohata, k., goto, r., & kitaoka-higashiguchi, k. (2008). work engagement in japan: development and validation of the japanese version of the utrecht work engagement scale. journal of applied psychology: an international review, 57, 510-523. sonnentag, s. (2003). recovery, work engagement, and proactive behavior: a new look at the interface between non-work and work. journal of applied psychology, 88, 518-528. storm, k., & rothmann, i. (2003). a psychometric analysis of the utrecht work engagement scale in the south african police service. south african journal of industrial psychology, 29, 62-70. xanthopoulou, d., bakker, a. b., demerouti, e., & kantas, a. (2007). the measurement of burnout and engagement: a cross-cultural study comparing greece and the netherlands. new review of social psychology. yi-wen, z., & yi-qun, c. (2005). the chinese version of the utrecht work engagement scale: an examination of reliability and validity. chinese journal of clinical psychology, 13, 268-270. mailto:topacademicjournals@gmail.com microsoft word 1033.doc academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset integrating thermodynamic and kinetic information: insights from pourbaix diagrams in electrochemistry dr. emily anne mitchell and dr. alexander james patel department of chemistry, york college, city university of new york abstract: in the pursuit of sustainable energy solutions and environmental preservation, the need to meet the growing energy demands of the modern world has become increasingly pressing. this challenge has ignited a concerted effort to identify and harness renewable energy sources. fuel cells have emerged as a promising avenue in this endeavor, primarily due to their ability to derive energy from solar power and the readily available supply of water. this paper delves into the quest for efficient catalysts to facilitate the reversible process of water splitting, a critical step in hydrogen production. furthermore, we explore the cathodic process of hydrogen oxidation in hydrogen fuel cells. this work draws inspiration from nature's hydrogenase enzymes, which exhibit remarkable efficiency in catalyzing both of these processes. the insights gained from studying hydrogenase enzymes offer valuable guidance in the design and development of hydrogenase-like catalysts, paving the way for cleaner and more sustainable energy production. keywords: renewable energy, fuel cells, water splitting, hydrogen production, hydrogenase enzymes 1. introduction the challenge of meeting the energy demands of the modern age while preserving environmental quality is driving a push towards finding renewable energy sources.1-5 fuel cells are one such target because the energy source can be garnered from solar power and the naturally abundant water supply.6 we are exploring ways to design efficient catalysts for reversibly carrying out the water splitting process. hydrogen production is a fundamental step in water splitting, and hydrogen oxidation is the cathodic process in a hydrogen fuel cell.7 hydrogenase enzymes catalyze both processes with extreme efficiency and are thus useful as a learning tool to help in the design of hydrogenase-like catalysts.8 in this paper, computational methods are applied to explore features of catalysts, inspired by hydrogenase enzymes, and evaluate their contributions to overall catalytic ability. the role of the ligand architecture and the influence of solvent on the catalysts’ ability to function in a thermodynamically realizable regime for protoncoupled electron-transfer processes are the primary focus. we adopt a systematic approach of describing a set of possible mechanistic routes for h2 production and oxidation and characterize the intermediates in order to elucidate the most energetically favored reaction mechanism. in the vast potential energy landscape of these model systems, this approach could reveal starting structures that can be used to explore transition states at critical junctures along the reaction coordinate. insight gained from understanding the mechanism of how these catalytic models function can be correlated with the electrochemical operating conditions of the experiments. together, the information offers the opportunity to recommend more efficient designs. this paper is organized as follows: section ii (background/motivation) introduces two crystal structures and corresponding data for experimentally characterized hydrogenase-inspired model catalysts that motivated this work; section iii (method) describes the computational approach of using free energy profiles and coupled pourbaix diagrams as a tool for understanding the reaction mechanism and determining the electrochemically tunable aspects of catalyst design; section iv mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (results) first introduces the proposed mechanistic routes of h2 oxidation and production and describes the intermediates. using these intermediates as the reference compound, free-energy profiles are calculated to establish the favored mechanistic route. next this section summarizes the properties of calculated coupled pourbaix diagrams which illustrate the optimal electrochemical operating regimes for the catalyst. section v (conclusion) summarizes the work and attempts to identify trends in the results. 2. background/motivation catalysts for hydrogen production and oxidation which utilize metal centers coordinated by diphosphine ligands with nitrogen pendent bases have been explored by several experimental groups.9-14 a recent review summarizes a series of hydrogenase mimics utilizing nickel and cobalt transition metals.15 these catalysts bear some structural resemblance to the active site of hydrogenase enzymes; they employ a nickel metal center as in the ni-fe hydrogenase, but only a single metal center at which hydrogen oxidation and production occurs. crystal structures have been characterized for these catalysts that indicate that the nickel center is in a 4-coordinate configuration with the two diphosphine ligands, indicative of the niii oxidation state.10,14,16-19 the diphosphine ligands and alkyl group substituents are oriented to place nitrogen atoms at a distance of around 3.4 å from the metal center. fig.1. compound a, [ni (pph 2n ph 2)2(ch3cn)](bf4)2 where pph 2n ph 2 is 1,3,5,7tetraphenyl-1,5-diaza-3,7 diphosphacyclooctane, has phenyl groups attached to the phosphorous and nitrogen base sites and an explicit acetonitrile ligated to the metal center.20,21 compound a has been shown to perform best as an h2 production catalyst. compound b, [ni (pcy 2n bz 2)2](bf4)2, has cyclohexyl (cy) groups on phosphorous and benzyl (bz) groups on the nitrogen base sites and has been shown to perform best as an h2 oxidation catalyst. however, the turnover frequency for these models is still well below that of the ni-fe hydrogenase enzyme. the natural enzyme has turnover rates of 700 s-1,20,22 while compound a has a turnover rate of 350 s-1 and compound b has a turnover rate of 10 s-1.20,21 the availability of the experimental structural and some kinetic data offers a good opportunity for theoretical methods to be used to characterize the effect of various features, or design principles, for such catalysts, and to understand which effects are likely to have the greatest influence in the reversibility and efficiency of future designs. using density functional theory coupled to implicit solvation schemes,23 the freeenergy profiles of proposed mechanistic routes, as well as the associated pka values and reduction potentials (e1/2), have been calculated for computational models of a and b. fig. 1: crystal structures from dubois references are: (a) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [ni(pph 2n ph 2)2(ch3cn)](bf4)2 pph 2n ph 2 = 1,3,5,7-tetraphenyl-1,5-diaza-3,7diphosphacyclooctane, shown to work in the h2 production direction; and (b) [ni(pcy 2n bz 2)2] shown to work in the h2 oxidation direction. 3. method a. computational method density functional theory (dft) was employed using the hybrid functional b3lyp24-26 and a 6-31g(d,p) (5d, 7f) basis set in the gaussian 03 program package.27,28 frequency calculations were performed at the optimized geometries to confirm minimum geometries and obtain the sum of electronic and thermal free energies for each species. atomic charge and spin populations were calculated at the optimized geometry to confirm the oxidation state of the metal center and charge state of the ligands. to obtain the free energy of solvation, a conductor-like polarizable continuum model (cpcm)29-32 was used to mimic the solvent, and the radii around the solute were carefully selected in such a way that charged species achieved greater interaction with the continuum through the use of smaller solvation radii.32,33 in this case, bondi radii34 were used, and two parameters were adjusted to provide the lowest solvation free-energy possible for the model.35,36 a sphere overlap index of 0.8å and minimum radius for added spheres of 0.5å were used based on a series of tests using the same functional and basis set. both adjustments result in a smaller number of added spheres. without these adjustments, the solvation free-energy remains too high and contributes to extremely acidic pka values, not in the range of the known experimental values.35,36 lowering the solvation free-energy by adjusting these parameters calibrates our method with the experimental values of the crystal structures provided. the only solvent considered throughout this paper is acetonitrile, as used in the experimental conditions. 1. pourbaix diagrams used for proton management. with the goal of understanding the mechanism for h2 oxidation and production in hydrogenase-inspired compounds, theory and experiment align to gain valuable insight into fundamental processes in these catalysts.7,37 the pourbaix diagram shows the thermodynamically stable form of a chemical species as a function of applied potential and ph, spanning all oxidation states accessible by redox reactions and/or acid/base reactions. the horizontal and diagonal lines plotted on the diagram are the half-potentials, i.e., the reduction potentials for all redox couples at the condition of equal concentration of the reduced and oxidized forms of the species, as a function of the solution ph. the vertical lines are the pka values of protonated forms of the species. fig. 2: schematic illustration of coupled pourbaix diagram. shaded region (green) is the overlap between the pcet regions of the nii/i and niiii/ii(h-) redox couples that must align at the same ph conditions to promote optimal catalyst performance for h2 oxidation or production. the red and blue pourbaix diagrams are coupled by mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset oxidative addition or reductive elimination reactions between intermediates connected by purple double-headed arrows and heterolytic cleavage or association reactions between intermediates connected by green double-headed arrows. for mechanisms that involve thermal reactions to produce intermediates not reached by redox processes, pourbaix diagrams can be combined in order to provide an effective description of the process, as in fig. 2. an example of such a thermal reaction is the rapid intramolecular proton transfer between a reduced metal center and a pendent base (i.e., reductive elimination or oxidative addition). coupled pourbaix diagrams can provide crucial information about the performance of a given catalyst. for example, if the mechanism operates by way of an oxidative addition reaction that transforms a nii to a niiii(h-) species that is the precursor to further redox chemistry, these two species must be able to coexist at similar ph and potential. furthermore, such a reaction would ideally have ∆g° = 0. a more detailed explanation of coupled pourbaix diagrams has been given in our previous paper.42 more fundamental details of the method are described in the supporting information. 2. p ka calculation. to be able to compare to experiments, the pka is calculated by constructing a thermodynamic cycle as shown in scheme 1 and similar in approach to ref 37.39,43 gg ha a-(g) + h+(g) g s(ha) gs(h ) ha(sol) a-(sol) + h+(sol) scheme 1 general thermodynamic cycle used to calculate pka in acetonitrile solvent. ∆gg is the free-energy change of the acid dissociation reaction in the gas phase where ∆gg = gg(a -) + gg(h +) – gg(ha) calculated with dft at 1 atm standard state.32,44 g solo δgo * pka 2.303rt (1) dgs o ol =dgg +ddgs o (2) in this construct, equations (1) and (2) are used to solve for the pka. ∆go sol is the free-energy change of the acid dissociation reaction in solution where ∆∆gsol = ∆gsol(a -) + ∆gsol(h +) – ∆gsol(ha).45 the solvation free energy was approximated with a polarizable continuum model (pcm) solvation model.30,39 the difference between standard states of the gas phase and solution phase is reconciled by the ∆go→* term, taken to be 1.89 kcal/mol.39 the solvation free-energy of the proton in acetonitrile solvent is taken from the literature to be -260.2 kcal/mol.46 the gas-phase free energy of the proton is also taken from the literature as a value of -6.28 kcal/mol, calculated from the sakur-tetrode equation.46 3. reduction potential calculation. to calculate the standard reduction potential, a second thermodynamic cycle is constructed as shown in scheme 2. in this construct, the nernst equation represented by equations (3) and (4) is used to solve for the reduction potential.46,47 gg ( g ) ) ( a s g o sol g mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset + ox(g) + mh (g) + ne hred(g) gs(ox) gs(h ) g 0 gs (hr ed) ox(sol) + mh+(sol) + ne (sol) hred(sol) scheme 2 general thermodynamic cycle used to calculate the reduction potential in acetonitrile solvent. (dgoox|red dgrohe ) e oox|red = (3) nf e=eoox|red rt lnæça red ÷öm×0.0591×ph (4) nf èaox ø n the absolute free energy of the normal hydrogen electrode dgr o hein acetonitrile solution was calculated to be 4.63v and is very close to the value of 4.48v reported in ref 37. eo o x|red is at unit (i.e., 1 molar) activity of oxidant and reductant (at ph 0). the reduction potential is related to the free energy that the catalyst needs to obtain n electrons from the normal hydrogen electrode via the reaction as in equation (5). h++eg ® (1/2) h2 (5) as illustrated in the thermodynamic cycle, the number of protons is designated by m and the number of electrons is designated by n. as such, the slope of the reduction potential with respect to ph is governed by the ratio m/n. the solvation free-energy of h2 is calculated in acetonitrile solution using the same optimization parameters as in the model systems. the inherent error arising from the approximations introduced by the implicit solvation model is estimated to be on the order of 0.09-0.13v. this error corresponds to pka differences of around 2 ph units with respect to the experiments. 4. results a. mechanistic routes for h2 oxidation/production. based on several studies on hydrogenase enzymes,19,48 the mechanism for h2 oxidation/production is thought to proceed via a heterolytically cleaved intermediate in which the hydride ion is attached to the metal center, forming a metal hydride, and the proton is attached to the base. we define this as type-i h2 bond cleavage. an alternative to this type-i h2 bond cleaved intermediate is the second heterolytically cleaved intermediate, which has been observed experimentally by nmr spectroscopy in some characterized catalyst models, in which both protons from the hydrogen molecule attach to different pendent base groups while the two electrons reduce the niii metal center to ni0. we define this as type-ii h2 bond cleavage. the ability to reach higher or lower oxidation states of the metal and to change the basicity of the pendent base(s) can be tuned by the choice of substituent on the catalyst as shown in our previous studies.42 in this paper, we describe possible mechanistic routes for h2 oxidation and production which involve type-i and typeii h2 bond cleaved intermediates. analysis of the intermediates appearing in nonelectrochemical and electrochemical reactions and the free-energies along these two main routes, type-i and type-ii h2 bond cleaved intermediates, can be linked to the experimental operating regime and offers insight into which conditions can be tuned for optimal catalyst performance. the possible mechanistic routes for both [ni(pph 2n ph 2)2(ch3cn)] and [ni(pcy 2n bz 2)2] models have been generically summarized in fig. 3. starting from the bare catalyst with the metal in the 2+ oxidation state, intermediate (0), upon addition of the h2 molecule leads to two main branches considered herein. the first branch ( g ) o red | ox g mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset leads to intermediate (1a) in which a type-ii bond cleaved h2 symmetrically protonates both nitrogen base sites and the electron reduces the metal to the ni0 state. in a recent publication, the ni0 intermediate is described as being important to intramolecular proton exchange processes in the cycle.49 the second branch leads to intermediate (1b) in which a type-i bond cleaved h2 asymmetrically protonates the nitrogen base site and adds a hydride (h-) to the metal center. the h2 addition reaction from intermediates 0 1 is considered a nonelectrochemical reaction and relies on a reasonable activation free energy needed to form either (1a) or (1b). the next step towards h2 oxidation is the first of the two electrochemical reactions shown in the chemical equation h2 2h+ + 2e-.50 these electrochemical reactions depend on the potential applied to the electrodes and the ph of the solution. the balance between ph and potential will dictate whether the proton and electron transfers occur sequentially or in a concerted manner described as proton-coupled electron transfer (pcet). as shown in fig. 3, if sequential electrochemical reactions occur then intermediates (2a), (2b), (3a), and (3b) can be isolated and characterized depending on whether intermediate (1a) or (1b) prevails after h2 addition. a key factor in h2 oxidation processes is the formation of a metal-hydride intermediate along the mechanistic route. in the case where intermediate (1a) is formed upon h2 addition, an additional non-electrochemical reaction is needed from intermediate 2 3 to form the key metal-hydride intermediate. in this oxidative addition, the proton on the nitrogen base gets donated to the ni0 as a hydride and oxidizes the metal to niii. in the case where intermediate (1b) is formed, the oxidative addition reaction is unnecessary because the metalhydride intermediate is already present. the next step towards h2 oxidation is another non-electrochemical reaction from intermediate 4 5. this reductive elimination is an intramolecular transfer where the hydride donates a proton the nitrogen base and an electron to reduce the metal from niiii to nii. lastly, the final step to complete h2 oxidation is the second of the two electrochemical reactions in the process. fig. 3. summary of mechanistic routes leading to h2 oxidation for nickel diphosphine model catalysts. intermediates along this direction are classified as reaction steps producing intermediates in the order, 0 1 2 3 4 5 6 0. the h2 production direction for the model is exactly the reverse process where the intermediates in the reaction steps are ordered by 0 6 5 4 3 2 1 0. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset again there will be a dependence on the applied potential and ph in determining if the reactions will be sequential or pcet. if sequential then intermediates (6a) or (6b) can be isolated and characterized. catalysis in the h2 production direction involves the 2h+ + 2e h2 reaction which allows us to consider the possible mechanistic routes as the reverse of the h2 oxidation direction previously described. for the non-electrochemical reactions, reductive elimination is the reverse of the oxidative addition reaction and h2 release is the reverse of the h2 addition reaction. these non-electrochemical processes are similarly governed by the kinetics of those reactions. for the electrochemical reactions, sequential or pcet processes are governed by the applied potential and ph of the reaction conditions. therefore, for ease in describing the intermediates in these mechanistic routes, we subdivide them into two categories, those encountered in the non-electrochemical reactions and those encountered in the electrochemical reactions. one reason is that the two categories of reactions can be controlled differently. the behavior of species involved in the non-electrochemical reactions can be controlled by knowing the structure and energy of the transition states and by tuning the ligands such that the intermediates are close in energy (i.e. ∆g = 0). the species involved in the electrochemical reactions can be controlled by tuning the ligands to control the ph in which they operate and tuning the metal to control the oxidation states reached when a potential is applied. we discuss these two categories next and discuss the calculated results of [ni(pph 2n ph 2)2(ch3cn)] and [ni(pcy 2n bz 2)2] model compounds. b. non-electrochemical intermediates non-electrochemical intermediates in h2 oxidation/production reactions are dominated by kinetic processes so it becomes important to describe the activation energy barrier in these reactions which can ultimately be compared to the rates achieved in the experiments. the two non-electrochemical intermediates for which we attempt to determine the transition states occur in fig. 3 between intermediates 0 1, which we define as the h2 adduct, and intermediates 4 5 which we define as a thermal reaction common to all mechanistic routes shown in fig. 3. 1. h2 adduct the energy of the intermediate formed upon h2 addition is one marker for the catalytic direction that the molecular catalyst favors. if the energy of the cleaved intermediate is favored (i.e. -∆g) with respect to the h2 adduct, the catalyst is likely to function as an h2 oxidation catalyst. otherwise, the catalyst prefers scavenging available electrons and protons from the reservoir, combining them to produce h2. as such we explored several possible conformers of the h2 adduct and quantified their energies with respect to the type-i or type-ii h2 bond cleaved intermediates. this will be a useful starting structure to use for transition state searches. beginning from different conformers of the h2 adduct to [ni(pcy 2n bz 2)2], three stable intermediates were located as shown in fig. 4(i), 4(ii) and 4(iii). cy bz mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 4. intermediates of the h2 adduct to [ni(p 2n 2)2] model. (i) loosely bound dihyrogen[niii…h2] 2+; (ii) strongly bound dihydrogen [niii(h2)] 2+; and (iii) dihydride [niiv(h-)2] 2+ trans axial the plane of the metal center and phosphorous atoms. table 1: intermediates of the h2 adduct for the [ni(pcy 2n bz 2)2] model. [niii…h2]2+ [niii(h2)]2+ [niiv(h)2]2+ trans axial bond length (å) (i) (ii) (iii) h1---h2 0.8 0.8 3.0 ni---h1 2.9 1.7 1.5 n---h1 2.4 2.4 2.8 angle (degrees) p1---ni---p2 81.5 81.2 82.8 p3---ni---p4 81.5 81.2 82.8 p1---ni---p3 158.6 169.2 105.1 p2---ni---p4 156.8 141.3 105.1 h1---ni---h2 14.6 25.8 180.0 p2---ni---p3 102.9 102.5 149.8 p1---ni---p4 102.9 102.4 150.0 these intermediates, labeled (i), (ii), (iii), ordered energetically from lowest to highest are [niii∙∙∙h2] 2+, [niii(h2)] 2+ and [niiv(h¯)2] 2+, respectively. bond distances shown in table 1 confirm the assignment of (i) as a dihydrogen loosely bound to the catalyst and (ii) as a dihydrogen strongly bound to the metal center, given the short hh bond of around 0.8 å. the (i) and (ii) intermediates have similar distances from the nearest h atom to the nitrogen base sites of approximately 2.4 å, a reasonable pt distance under the appropriate acid/base conditions. the third h2 adduct, (iii), is a trans axial dihydride across the plane of the metal center and the four phosphorous atoms, and has longer distances between the hydride and nitrogen of around 2.8 å. the trans axial positioning of the hydrides across the metal phosphide plane was the only possible dihydride complex that could be found for this catalyst model given the low flexibility of the boat/boat configuration of the diphosphine rings with respect to the metal center. on the other hand, starting from many different conformers, the h2 adduct to [ni(pph 2n ph 2)2(ch3cn)] converged to four stable intermediates, ordered energetically from lowest to highest in fig. 5. similar to the [ni(pcy 2n bz 2)2] model, intermediates (i’), (ii’) and (iii’) are the loosely bound dihydrogen, strongly bound dihydrogen and trans axial dihydride respectively, as shown by the bond distance and angles in table 2. however, an additional h2 adduct found for this system is a complex with the dihydride atoms on the same face of the metal-diphosphine plane, third highest in energy from the other h2 adducts, as shown in figure 6. for this case, both hydride ions remain on the same side of the metal phosphide plane because the boat/chair conformation of the diphosphine rings offers more flexibility at the metal center. this dihydride intermediate [niiv(h¯)2(ch3cn)]2+ has nickel hydride bond lengths of 1.5å, similar to the dihydride of the [ni(pcy 2n bz 2)2] model. figure 6 summarizes the comparison of the energies of the various h2 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset adducts with respect to the type-ii h2 bond cleaved (1a) and type-i h2 bond cleaved (1b) intermediates for the two models. figure 6(a) for the [ni(pph 2n ph 2)2(ch3cn)] model shows that the dihydride intermediate (iv’) is nearly isoenergetic with the type-ii h2 bond cleaved intermediate (1a), differing in energy by 0.06 ev. figure 6(b) for the [ni(pcy 2n bz 2)2] model shows that the energies of the loosely bound dihydrogen complex (i) and the type-i h2 bond cleaved [niii(h-)-nh+]2+ intermediate (1b) are nearly isoenergetic, differing by only 0.023 ev. likewise, the energies of the dihydride (iii) and the typeii h2 bond cleaved intermediates (1a) are relatively similar, differing by 0.14 ev. the h2 adduct nearest in energy to the type-i or type-ii h2 bond cleaved species is a good starting point for locating the transition state of this initial step and efforts are underway in this search. the trend in figure 6 shows that formation of the type-ii h2 bond cleaved intermediate (1a) will likely be preceded by a dihydride intermediate, and similarly, formation of the type-i h2 bond cleaved intermediate (1b) will likely be preceded by the dihydrogen complex. fig. 5: intermediates of the h2 adduct to [ni(pph 2n ph 2)2(ch3cn)] model. (i’) loosely bound dihydrogen [niii…h2] 2+; (ii’) strongly bound dihydrogen [niii(h2)] 2+; (iii’) trans axial dihydride [niiv(h-)2] 2+ and (iv’) [niiv(h¯)2] 2+ dihydride intermediate. table 2: intermediates of the h2 adduct for the [ni(pph 2n ph 2)2(ch3cn)] model ordered energetically from lowest to highest. [niii...h2]2+ [niii(h2)]2+ [niiv(h)2]2+ [niiv(h)2]2+ trans axial bond length (å) (i’) (ii’) (iv’) (iii’) h1---h2 0.8 0.8 1.9 3.0 ni---h1 2.8 1.8 1.5 1.5 n---h1 2.5 2.5 2.2 2.6 ni---ncch3 4.8 4.8 5.8 4.6 angle (degrees) p1---ni---p2 83.5 83.6 84.8 84.1 p3---ni---p4 83.6 83.5 84.8 84.1 p1---ni---p3 171.7 171.7 161.1 150.9 p2---ni---p4 137.8 137.8 109.3 153.4 h1---ni---h2 16.4 25.6 81.4 180.0 ) ii' ( ) iii’ ( iv’ ( ) ( i ') mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset p2---ni---p3 99.6 99.3 106.3 102.6 p1---ni---p4 99.3 99.6 106.3 102.6 the stability of these h2 adduct intermediates, as confirmed by gas phase frequency calculations, may offer insight into the nature of the transition state needed to reach the type-i or type-ii h2 bond cleaved intermediate. fig. 6. energetics of the h2 adduct with respect to the type-i and type-ii h2 bond cleaved intermediates. energy differences are taken with respect to the free catalyst and h2. 2. thermal reaction common to all mechanistic routes – intermediates and transition states the second non-electrochemical reaction along the h2 production mechanistic route is an oxidative addition involving intermediates 5 → 4 of fig. 3, the reverse of which is considered a reductive elimination. in an optimal catalyst, the freeenergy for this step should be nearly isoenergetic (i.e. ∆g 0) and the free-energy of activation (∆g ) should be low. we calculate the transition state at this reaction step to understand the structure and energetics of the reacting species. fig. 7 shows the structures of the transition states characterized by the negative eigenvalue of the hessian matrix along the donor/acceptor mode between the metal center and the nitrogen base site of compounds a and b. distances and angles of the reacting species are shown in table 3 for the [ni(pph 2n ph 2)2(ch3cn)] model and table 4 for the [ni(pcy 2n bz 2)2] model. the tables show that the transferring proton is approximately midway between the donor atom (ni) and the acceptor atom (n) for both compounds. a b mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 7. oxidative addition transition state, between intermediates 5 → 4, for compound a, [ni(pph 2n ph 2)2(ch3cn)] model and compound b, [ni(pcy 2n bz 2)2] model. the transferring proton is midway between the donor atom (ni) and acceptor atom (n). table 3 oxidative addition 5 → 4 in the [ni(pph 2n ph 2)2(ch3cn)] model for h2 production. intermediate (4) transition state intermediate (5) bond length (å) p ts r ni---h1 1.46 1.67 2.86 n---h1 2.31 1.46 1.03 ni---ncch3 5.78 5.75 5.47 frequency of ni—h—n mode (cm-1) -- 921.01i -- angle (degrees) p1---ni---p2 86.07 82.52 85.51 p3---ni---p4 83.54 82.92 86.44 p1---ni---p3 159.78 157.99 145.20 p2---ni---p4 109.77 112.92 121.54 p2---ni---p3 107.39 105.56 111.98 p1---ni---p4 106.49 106.54 110.48 ∆go s (r & p) (ev) ∆g (ts) (ev) relative to reactant 0.32 0.60 0.00 in the [ni(pph 2n ph 2)2(ch3cn)] model, the flexibility of the boat/chair configuration allows for large rearrangements of the angles around the diphosphine plane. for example, the p1---ni---p3 and p2---ni---p4 angles undergo the largest changes between the reactant (r), transition state (ts) and product (p) configurations, shown in table 3. the constraint of the boat/boat configuration in the [ni(pcy 2n bz 2)2] model shows much less rearrangement of the angles between the (r), (ts) and (p), as seen in table 4. comparing the transition states of the two compounds, table 3, shows that the p---ni---p angles of the (ts) have more product character than reactant character while table 4 shows the opposite behavior for the [ni(pcy 2n bz 2)2] model. in other words, both transition states have diphosphine bite angles similar to intermediate (4) of fig. 3. this implies that the barrier for oxidative addition will be higher than the barrier for reductive elimination. given nature of the transition state structurally appears to be associated with the bite angle and is therefore impacted by the amount of steric bulk from the ligands. as such, consideration should be given to designing the catalyst with some flexibility in the first coordination shell to the metal center. table 4: reductive elimination 4 → 5 in the [ni(pcy 2n bz 2)2] model for h2 oxidation. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset intermediate (4) transition state intermediate (5) bond length (å) r ts p ni---h1 1.46 1.74 2.91 n---h1 2.79 1.68 1.03 frequency of ni—h—n mode (cm-1) -- 654.89i -- angle (degrees) p1---ni---p2 82.07 82.06 82.49 p3---ni---p4 82.06 82.07 83.62 p1---ni---p3 152.66 152.66 147.20 p2---ni---p4 147.62 147.02 146.35 p2---ni---p3 105.80 105.79 105.94 p1---ni---p4 105.79 105.80 107.08 ∆go s (r & p) (ev) ∆g (ts) (ev) relative to reactant 0.00 0.48 -1.07 c. electrochemical intermediates the second category of intermediates along h2 oxidation/production mechanistic routes are the electrochemical intermediates, those involving redox and acid/base reactions. in fig. 3, the first of the two electrochemical steps in the 2h+ + 2e→ h2 reaction occurs between intermediates (1) and (4), and the second occurs between intermediates (5) and (0). the electrochemical reactions can be sequential pt and et or concerted pcet. if sequential, the order of et followed by pt or vice versa is not easily determined a priori and depends on the ph of the experimental conditions, along with the potential needed to reach redox species along the mechanistic route. therefore, we calculate the free-energy profile along various mechanistic routes to understand which species are energetically likely to dominate. d. free-energy comparison of type-i and type-ii h2 bond cleaved mechanistic routes the characterized catalyst (a), has been shown to operate as an h2 production catalyst while (b) has been shown to operate as an h2 oxidation catalyst. as such, we explore the free-energy profiles of each calculated model catalyst along the catalytic direction in which they are thought to operate. an important component in determining the mechanism is the formation of the h2 adduct as the first step in the h2 oxidation direction. as such, this importance is highlighted by using a proposed adduct as the reference compound in the free energy profiles, instead of the bare catalyst plus a gas phase hydrogen molecule. in doing so, the magnitude of the free energy of key steps (i.e. pcet and electrochemical steps) is similar to the corresponding free energy steps of our previous paper.42 efforts are underway to determine the true transition state of these key steps. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1. h2 production in [ni(pph 2nph 2)2(ch3cn)]. free-energy calculations on the [ni(pph 2n ph 2)2(ch3cn)] model were performed, and will be discussed here in the catalytic direction for h2 production. figure 8 illustrates the calculated free-energy versus the reversible hydrogen electrode (rhe) along the proposed h2 production mechanistic routes at ph = 0. intermediates along the reaction coordinate, emphasizing the distinction between the two type-ii h2 bond cleaved (paths 1 and 2) and two typei h2 bond cleaved (paths 3 and 4) routes are explained in the caption. fig. 8: summary of mechanistic routes leading to h2 production of [ni(pph 2n ph 2)2(ch3cn)] at conditions of ph = 0. energy differences are taken with respect to the first point, the h2 adduct, and normalized to the reversible hydrogen electrode (rhe). intermediates involved in each route are: type-ii path 1(blue): 0 6a 5 4 3a 2a 1a 0. type-ii path 2(orange): 0 6a 5 4 3b 2b 1a 0. type-i path 3(green): 0 6b 5 4 3a 1b 0. type-i path 4(purple): 0 6b 5 4 3b 1b 0. in figure 8, the type-ii h2 bond cleaved routes are the ones in which intermediate (1a) is involved in the mechanism and type-i h2 bond cleaved routes involve intermediate (1b). panel (a) illustrates that when the two type-ii h2 bond cleaved routes are compared, path 1 (blue), which follows intermediates 0 6a 5 4 3a 2a 1a 0, is a lower energy route than path 2 (orange). the ni0nh+ (2a) and niii(h-)-n (3a) are lower in energy than +hn-nii-nh+ (2b) and niiii(h-)-nh+ (3b). panel (b) illustrates that when the type-i h2 bond cleaved routes are compared, path 3 (green) which follows intermediates 0 6b 5 4 3a 1b 0, is a lower energy route than path 4 (purple). again, the difference here is that niii(h-)-n (3a) is lower in energy than niiii(h-)-nh+ (3b). panel (c) then compares the lowest energy route for both type-i and type-ii h2 bond cleaved routes, paths 1 and 3, and is a key feature in this energy analysis. the comparison shows that the first electrochemical step, involving intermediates 0 → 5 is nearly isoenergetic. viability of this first electrochemical step becomes important for the discussion in section iv c about the appropriate ph regime at which the experiment should be operated. the subsequent electrochemical step leads to the [nii-nh+]2+ reduced metal, protonated base defined as intermediate (5). if pcet conditions prevail, then intermediate (6) is not observed, otherwise intermediate (6a) would be favored. the oxidative addition that follows, common to all four proposed mechanistic routes, in which the base loses the proton to the metal center as a hydride forming the [niiii(h)-n]2+ intermediate (4), has an mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset associated free-energy change of 0.324 ev (7.47 kcal/mol). the second electrochemical reaction involving intermediates 4 → 1, show significant deviation between type-i and type-ii h2 bond cleaved routes. focusing on the h2 adduct that is formed in intermediate 1, before release of the h2 molecule, intermediate 1a is 0.369 ev higher in energy than intermediate (1b). however, since the intermediate (1a) is higher in energy than the dihydrogen complex (iii) then h2 release is favored, making this route consistent with the experimentally characterized results of the h2 production catalyst. the dihydrogen h2 adduct was chosen as the reference compound for this comparison. fig. 9. type-ii h2 bond cleaved path 1 for h2 production of the [ni(pph 2n ph 2)2(ch3cn)] model catalyst. the intermediates along this path are 0 6a 5 4 3a 2a 1a 0. fig. 9 summarizes the type-ii h2 bond cleaved mechanistic route 1 for the [ni(pph 2n ph 2)2(ch3cn)] model. under the appropriate ph conditions, a proton from the solution can attach to the catalyst at a nitrogen base site (6b), or an electron from an applied potential can reduce the metal center, from niii to nii (6a). depending on whether intermediate (6a) or (6b) is formed, a subsequent electron transfer (et) or proton transfer (pt) leads to the reduced metal with a protonated base, intermediate (5). the increased basicity of the metal center then causes the proton to transfer from the pendent base to the metal to form the metal-hydride, intermediate (4), through an oxidative addition reaction (fig. 3, step 5 → 4). the next step (fig. 3, step 4 → 3), is again determined by the ph of the solution or the applied potential. if the ph allows for the availability of protons, the base becomes protonated, forming the metal-hydride with a protonated base (3b). otherwise, an appropriate applied potential forms the reduced metal-hydride (3a). of the two intermediates formed in step 4 → 3, (3a) and (3b), each has two alternatives along the reaction coordinate to h2 production. if the reduced metal-hydride (3a) is formed, it can undergo pt immediately or as a second step after reductive elimination. if the pt from the solution to the catalyst is favored, the type-i h2 bond cleaved intermediate (1b) is formed. if reductive elimination is favored, the hydride transfers from the metal to form a proton on the pendent base as intermediate (2a). then under the appropriate ph conditions, a second pendent base becomes protonated forming the type-ii h2 bond cleaved intermediate (1a). if the metalhydride with the protonated base, intermediate (3b), is formed, it can either undergo a one-electron reduction immediately or as a second step after reductive elimination. if the reduction occurs immediately, the type-i h2 bond cleaved intermediate [niii(h-)nh+]2+ intermediate (1b) is formed. if the reduction occurs as a second step, reductive elimination forms [+hn-nii-nh+]3+ as intermediate (2b) first, then forms the type-ii h2 bond cleaved [+hn-ni0-nh+]2+ as intermediate (1a). in the last step 0 → 1, the two hydrogen ions on the molecular catalyst combine with two electrons from the metal to release an h2 molecule. 2. h2 oxidation in [ni(pcy 2nbz 2)2]. free energy calculations of similar type-i and type-ii h2 bond cleaved pathways in the catalytic direction for h2 oxidation with the [ni(pcy 2n bz 2)2] model were performed. experimentally, the [ni(pcy 2n bz 2)2] catalyst was observed to favor h2 oxidation, so here we explore comparisons to the experimental system in that catalytic direction. figure 10 shows the calculated free-energy profile of this model at ph = 0. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 10. summary of mechanistic pathways leading to h2 oxidation with the [ni(pcy 2n bz 2)2] model at conditions of ph = 0. energy differences are taken with respect to the first point and normalized to the reversible hydrogen electrode (rhe). intermediates involved in each route are: type-ii path 1 (blue): 0 1a 2a 3a 4 5 6a 0. type-ii path 2 (orange): 0 1a 2b 3b 4 5 6a 0. type-i path 3 (green): 0 1b 3a 4 5 6b 0. type-i path 4 (purple): 0 1b 3b 4 5 6b 0. in figure 10, the reference compound for which the energies are plotted is the dihydrogen adduct (ii), chosen for its low energy stability compared to the other calculated h2 adducts. panel (a) shows that the type-ii h2 bond cleaved intermediate (1a) is 0.151 ev (3.48 kcal/mol) higher in energy than the h2 adduct. the first electrochemical reaction follows, between intermediates 1 → 4. in this model, special attention is paid to intermediates 1a and 3a because these have both been observed with nmr spectroscopy using the characterized compounds.21 following the route of the nmr observed intermediates, path 1 (blue) traverses intermediates 0 1a 2a 3a 4 5 6a 0. however, intermediate (2a) is 0.753 ev (17.37 kcal/mol) higher in energy than intermediates (1a). the next step is a non-electrochemical, reductive elimination reaction, consistent in all four mechanistic routes between intermediate 4 → 5. the energy of which is downhill by 0.585 ev (13.49 kcal/mol). the second electrochemical reaction occurs between intermediate 5 → 0. panel (b) shows that the type-i h2 bond cleaved intermediate (1b) is -0.203 ev (4.68 kcal/mol) lower in energy than the h2 adduct reference compound which is consistent with this model as an h2 oxidation catalyst. in the next electrochemical reaction between 1 → 4, if pcet conditions prevail, then intermediate 3 is not observed, otherwise intermediate (3a) would be favored. a schematic description of this energetically favored typei h2 bond cleaved path 4 is shown below in fig. 11. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 11. energetically favored type-i h2 bond cleaved path 4 for h2 oxidation of the [ni(pcy 2n bz 2)2] model catalyst. the intermediates along this path are 0 1b 3b 4 5 6b 0. c. electrochemical perspective from calculated pourbaix diagrams one criterion for molecular catalyst design is energy matching in the nonelectrochemical reaction steps. however, an additional condition to improve the efficiency of the catalyst is to control the electrochemical reactions so that the energy cost of sequential proton and electron transfer is circumvented by steering the reduction to proceed by pcet. the goal then becomes to align all intermediates involved in the nonelectrochemical reaction steps such that they are available at similar ph ranges. hence, for the electrochemical reactions, an applied potential, at a ph, will facilitate the most efficient mechanistic route due to the availability of the most relevant species. we demonstrate this idea using the coupled pourbaix diagram, a plot of potential versus ph where the identity of the various species has been described in the methods section above. a schematic of an expanded pourbaix diagram illustrating all intermediates in both type-i and type-ii h2 bond cleaved routes is shown in fig. 12. the type-ii h2 bond cleaved route shown in purple arrows in fig. 12 is expanded schematically in fig. 13. the ideal, most efficient mechanism would involve only pcet reactions which overlap in the ph ranges of the protoncoupled electron-transfer steps, pcet12, pcet34 and pcet56, and occur at similar potentials. the schematic pourbaix diagram in fig. 12 is broadly applicable to both catalysts models. having mapped out two relevant mechanistic routes, type-i and type-ii h2 bond cleaved, of these molecular catalyst models, a connection must be made to the operational ph and potential where the intermediates are accessible. we turn to the calculated coupled pourbaix diagrams to make this necessary connection and attempt to draw correlations to the operational regimes used in the experimental setup. fig. 14 is the coupled pourbaix diagram of model [ni(pcy2nbz2)2]. intermediates involved in the type-ii h2 bond cleaved routes are shaded in purple, and intermediates involved in the type-i h2 bond cleaved routes are shaded in green. pka’s for the h2 adducts correspond to the single deprotonation of the (i), (ii) and (iii) intermediates to [niii(h-)-n]. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 12. schematic of an expanded coupled pourbaix diagram. red lines signify the niii/nii couple, blue lines are the niiii/ii(h-) couple, and purple lines are the nii/0 couple. numbered intermediates followed by purple arrows travel along the type-ii h2 bond cleaved pathway. the intermediates labeled with circled numbers follow the type-ii h2 bond cleaved pathway as an illustration that free-energy mechanistic routes can be mapped onto the pourbaix diagram at a way to interpret findings from electrochemistry experiments. fig. 13. type-ii h2 bond cleaved pathway of h2 oxidation with [ni(pcy 2n bz 2)2] model. focusing first on the pcet overlap region highlighted in purple which represents the type-ii h2 bond cleaved route, the results show that this route operates in a basic region of the ph scale and with relatively large overpotentials. interestingly, the experiment is performed in the presence of triethylamine, a strong base buffer, which could explain why the [+hn-ni0-nh+] intermediate is observed by nmr spectroscopy under these basic conditions. now focusing on the pcet overlap region highlighted in green, representing the type-i h2 bond cleaved route, the result shows that this route operates in an acidic region of the ph scale with much lower overpotentials than the type-ii h2 bond cleaved route. interestingly, the h2 adduct represented by (ii) and (iii) in fig. 14 falls within this ph range which is consistent with the similarity in energy to the type-i h2 bond cleaved intermediate. comparing the operating regimes of both type-i and type-ii h2 bond cleaved routes, this pourbaix diagram of [ni(pcy 2n bz 2)2], indicates that if the solution can be tuned to more acidic conditions, the intermediates reached will traverse a lower energy, thus a more favorable mechanistic route. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cy bz fig. 14. coupled pourbaix diagram of model [ni(p 2n 2)2]. intermediates involved in the type-ii h2 bond cleaved pathway are shaded in purple, and intermediates involved in the type-i h2 bond cleaved pathway are shaded in green. figure 15 is the coupled pourbaix diagram of model [ni(pph 2n ph 2)2(ch3cn)]. focusing on the pcet overlap region highlighted in purple in fig. 15 which represents the type-ii h2 bond cleaved route, a largely acidic ph range is involved with accompanying large overpotentials. in this case, the experiment is performed in the presence of triflic acid, which correlates with the strongly acidic ph range calculated. unlike the [ni(pcy 2n bz 2)2] case, this case appears to be more difficult to disentangle. from the free-energy profiles, the favored mechanism for this case appears to be along the type-i h2 bond cleaved pathway because of the 0.354 ev lower energy of the type-i h2 bond cleaved intermediate. however, the type-i h2 bond cleaved route falls in a narrow, even more acidic region of the pourbaix diagram but equally close to the acidic region of the type-ii h2 bond cleaved route, although with much lower overpotential. it may be that under the acidic conditions required by both routes, pcet reactions dominate and optimal conditions for the reactions prevail. fig. 15: coupled pourbaix diagram of model [ni(pph 2n ph 2)2(ch3cn)]. comparing the pourbaix diagrams of this [ni(pph 2n ph 2)2(ch3cn)] model and the previous [ni(pcy 2n bz 2)2] model, lower potentials are needed to drive the reaction in this case and may be one contributing factor to the higher turnover frequency (tof) of 350 s-1 of this catalyst as opposed to the tof of 10 s-1 of the previous one. the other mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset contributing factor being the lower change in free-energy of the oxidative addition reaction involving intermediates 5→ 4. 5. discussion in our previous paper42, explicit emphasis was placed on matching the pka’s of intermediates 4 & 5 (the oxidative addition step) such that the free energy of this step is thermoneutral in an ideal catalyst. our exploration of these actual catalysts shows that there are pka regions of overlap for each catalyst, favoring the type-ii route. while the pka’s overlap, the reduction potentials do not and may be a source of explanation for why these two catalysts have less than ideal turnover frequencies in their h2 oxidation/reduction directions. the pka’s for intermediates 4 and 5 are shown in figures 14 and 15. while the previous work also postulated a second reduction to the ni0 species before the oxidative addition step, this was not observed for these real catalyst systems. in fact, we show the calculated pka of the ni0 species in figures 14 and 15 (labeled in purple as the intermediates around pcet56). one of the strengths of the pourbaix diagram is the opportunity to explore the mechanism in terms of the ph dependence of various routes. so far the results have presented the simple case, at ph = 0 conditions, of proton transfers being coupled to electron transfers in what is usually defined as intermolecular pcet. however, a second, more complex process can be considered involving the coupling of oxidative additions to electron or proton transfers in a way that is traditionally defined as intramolecular pcet. one paper argues that b3lyp is not in qualitative agreement with coupledcluster expansion calculations on a model system of the nickle-diphosphine compound.51 the choice of using dft with a b3lyp functional for these calculations is based on seeking a qualitative understanding of how pourbaix diagrams can be used to design molecular catalysts at the low computational cost of calculating pka’s and reduction potentials of the full system, not a truncated model. 6. conclusion in search of renewable energy sources as a way of preserving the environment, nature’s energy producers have become an attractive instructor. hydrogenase enzymes, for example, are capable of turning over hydrogen at high rates using readily available and cost effective nickel and iron metals. while recognizing the complexity with which hydrogenases function, a few design features have been taken as a start towards building molecular catalysts which can function at comparable efficiencies. experimentalists have characterized such compounds, two of which we chose to model in this paper, one for h2 oxidation and the other for h2 production. using these models, we explored three aspects of catalytic function which can influence the choices made in designing the catalyst. the goal is to elucidate how to tune design features on the catalyst to improve efficiency, and to formulate a computational protocol which predicts how the changes ultimately affect catalyst behavior. by first mapping the free energy along a proposed reaction coordinate, we illustrate that we can decipher the mechanistic routes of the characterized catalyst and project ways to improve the catalyst by designing it to traverse more favorable routes. we then target the h2 adduct as a critical intermediate by which the pathway can be controlled and suggest design features that coerce the catalyst into forming certain low energy intermediates. lastly, we correlate the free-energy routes with electrochemical mapping of the intermediates as a way to project optimal electrochemical conditions for improving catalyst behavior. the key result from analyzing the free-energy profiles is that the heterolytic route is favored for both models, [ni(pph 2n ph 2)2(ch3cn)] and [ni(pcy 2n bz 2)2]. this suggests that using ligands to make one of the two nitrogens in the upper plane of the catalyst more basic than the other can bias the reaction to reach the heterolytically cleaved intermediate. when both nitrogens have the same ligand, homolytic cleavage is more difficult to avoid. the synthetic challenge of course becomes how to construct a catalyst with an asymmetric [ni(pphnph) (pphnbz)] configuration. however, if this can be overcome, this new asymmetric catalyst may traverse the optimal mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset heterolytically cleaved route. in analyzing the h2 adduct intermediate, structure appears to have a large contribution in controlling whether the homolytic or heterolytic intermediate is formed. formation of a loosely bound dihydrogen complex is nearly isoenergetic with the heterolytically cleaved intermediate and is best achieved by the complex that has diphosphine rings in the boat/boat configuration. lastly, since potential is proportional to the free-energy, lower potentials correlate with smaller cost in free-energy. from the perspective of the pourbaix diagrams, the results indicate that lower potentials are needed in acidic ph regions. thus, if the asymmetric catalyst can be stabilized in acidic solution through the phenyl ligands, all optimal conditions should prevail. while concepts of proton management have been considered by many investigators in the catalysis community,52 we are unaware of another study which hinges on the connection between free-energy profiles and pourbaix diagrams as a tool to design more efficient h2 oxidation and production catalysts. our paper is the second in this direction and hopes to gain greater appeal based on the electrochemical insight that it offers. further studies of this nature will of course rely on the availability of experimental data in the initial stages. however, the outcome of this study shows great promise in the future of designing efficient catalysts having a larger electrochemical component. acknowledgements the work at bnl was supported by doe under contract de-ac0298ch10886 (division of chemical sciences and its scientific user facilities division). this research utilized resources at the new york center for computational sciences (nyccs) at stony brook university/brookhaven national laboratory which was supported by the u.s. department of energy under contract no. de-ac02-98ch10886 and by the state of new york, and at the bnl center for functional nanomaterials (cfn). references arnold, f. h. nature 2001, 409, 253-257. cortright, r. d.; davda, r. r.; dumesic, j. a. nature 2002, 418, 964-967. kamat, p. v. journal of physical chemistry c 2007, 111, 2834-2860. ni, m.; leung, m. k. h.; leung, d. y. c.; sumathy, k. renewable & sustainable energy reviews 2007, 11, 401425. lubitz, w.; reijerse, e. j.; messinger, j. energy & environmental science 2008, 1, 1531. kudo, a.; kato, h.; tsuji, i. chemistry letters 2004, 33, 1534-1539. chong, d. s.; georgakaki, i. p.; mejia-rodriguez, r.; samabria-chinchilla, j.; soriaga, m. p.; darensbourg, m. y. dalton transactions 2003, 4158-4163. rauchfuss, t. b. science 2007, 317, 43-43. berning, d. e.; miedaner, a.; curtis, c. j.; noll, b. c.; dubois, m. c. r.; dubois, d. l. organometallics 2001, 20, 1832-1839. dubois, m. r.; dubois, d. l. comptes rendus chimie 2008, 11, 805-817. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset jacobsen, g. m.; shoemaker, r. k.; mcnevin, m. j.; dubois, m. r.; dubois, d. l. organometallics 2007, 26, 5003-5009. curtis, c. j.; miedaner, a.; ciancanelli, r.; ellis, w. w.; noll, b. c.; dubois, m. r.; dubois, d. l. inorganic chemistry 2003, 42, 216-227. yang, j. y.; bullock, r. m.; dougherty, w. g.; kassel, w. s.; twamley, b.; dubois, d. l.; dubois, m. r. dalton transactions, 39, 3001-3010. yang, j. y.; bullock, r. m.; shaw, w. j.; twamley, b.; fraze, k.; dubois, m. r.; dubois, d. l. journal of the american chemical society 2009, 131, 59355945. dubois, d. l.; bullock, r. m. european journal of inorganic chemistry 2011, 10171027. dubois, m. r.; dubois, d. l. chemical society reviews 2009, 38, 62-72. pool, d. h.; dubois, d. l. journal of organometallic chemistry 2009, 694, 28582865. redin, k.; wilson, a. d.; newell, r.; dubois, m. r.; dubois, d. l. inorganic chemistry 2007, 46, 1268-1276. wilson, a. d.; fraze, k.; twamley, b.; miller, s. m.; dubois, d. l.; dubois, m. r. journal of the american chemical society 2008, 130, 1061-1068. wilson, a. d.; newell, r. h.; mcnevin, m. j.; muckerman, j. t.; dubois, m. r.; dubois, d. l. journal of the american chemical society 2006, 128, 358-366. wilson, a. d.; shoemaker, r. k.; miedaner, a.; muckerman, j. t.; dubois, d. l.; dubois, m. r. proceedings of the national academy of sciences of the united states of america 2007, 104, 6951-6956. frey, m. chembiochem 2002, 3, 153-160. andzelm, j.; kolmel, c.; klamt, a. journal of chemical physics 1995, 103, 9312-9320. becke, a. d. physical review a 1988, 38, 3098-3100. becke, a. d. journal of chemical physics 1993, 98, 5648-5652. lee, c. t.; yang, w. t.; parr, r. g. physical review b 1988, 37, 785-789. frisch, a.; frisch, m. j.; trucks, g. w. gaussian 03 user's reference; gaussian: carnagie, pa, 2003. frisch, m. j.; trucks, g. w.; schlegel, h. b.; scuseria, g. e.; robb, m. a.; cheeseman, j. r.; jr, j. a. m.; vreven, t.; kudin, k. n.; burant, j. c.; millam, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset j. m.; iyengar, s. s.; tomasi, j.; barone, v.; mennucci, b.; cossi, m.; scalmani, g.; rega, n.; petersson, g. a.; nakatsuji, h.; hada, m.; ehara, m.; toyota, k.; fukuda, r.; hasegawa, j.; ishida, m.; nakajima, t.; honda, y.; kitao, o.; nakai, h.; klene, m.; li, x.; knox, j. e.; hratchian, h. p.; cross, j. b.; bakken, v.; adamo, c.; jaramillo, j.; gomperts, r.; stratmann, r. e.; yazyev, o.; austin, a. j.; cammi, r.; pomelli, c.; ochterski, j. w.; ayala, p. y.; morokuma, k.; voth, g. a.; salvador, p.; dannenberg, j. j.; zakrzewski, v. g.; dapprich, s.; daniels, a. d.; strain, m. c.; farkas, o.; malick, d. k.; rabuck, a. d.; raghavachari, k.; foresman, j. b.; ortiz, j. v.; cui, q.; baboul, a. g.; clifford, s.; cioslowski, j.; stefanov, b. b.; liu, g.; liashenko, a.; piskorz, p.; komaromi, i.; martin, r. l.; fox, d. j.; keith, t.; al-laham, m. a.; peng, c. y.; nanayakkara, a.; challacombe, m.; gill, p. m. w.; johnson, b.; chen, w.; wong, m. w.; gonzalez, c.; pople, j. a.; gaussian, inc.: wallingford, ct, 2003. takano, y.; houk, k. n. journal of chemical theory and computation 2005, 1, 7077. ginovska, b.; camaioni, d. m.; dupuis, m.; schwerdtfeger, c. a.; gil, q. journal of physical chemistry a 2008, 112, 10604-10613. klamt, a.; schuurmann, g. journal of the chemical society-perkin transactions 2 1993, 799-805. liptak, m. d.; shields, g. c. journal of the american chemical society 2001, 123, 7314-7319. barone, v.; cossi, m.; tomasi, j. journal of chemical physics 1997, 107, 3210-3221. bondi, a. journal of physical chemistry 1964, 68, 441-&. chauvin, r. journal of physical chemistry 1992, 96, 9194-9197. rowland, r. s.; taylor, r. journal of physical chemistry 1996, 100, 7384-7391. zhao, x.; georgakaki, i. p.; miller, m. l.; mejia-rodriguez, r.; chiang, c. y.; darensbourg, m. y. inorganic chemistry 2002, 41, 3917-3928. nunes, g. s.; alexiou, a. d. p.; araki, k.; formiga, a. l. b.; rocha, r. c.; toma, h. e. european journal of inorganic chemistry 2006, 1487-1495. kelly, c. p.; cramer, c. j.; truhlar, d. g. journal of physical chemistry b 2006, 110, 16066-16081. cukier, r. i.; nocera, d. g. annual review of physical chemistry 1998, 49, 337-369. meyer, t. j.; huynh, m. h. v.; thorp, h. h. angewandte chemie-international edition 2007, 46, 5284-5304. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 5; september october 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset small, y. a.; dubois, d. l.; fujita, e.; muckerman, j. t. energy & environmental science, 4, 3008-3020. qi, x. j.; liu, l.; fu, y.; guo, q. x. organometallics 2006, 25, 5879-5886. schuurmann, g.; cossi, m.; barone, v.; tomasi, j. journal of physical chemistry a 1998, 102, 6706-6712. tissandier, m. d.; cowen, k. a.; feng, w. y.; gundlach, e.; cohen, m. h.; earhart, a. d.; coe, j. v.; tuttle, t. r. journal of physical chemistry a 1998, 102, 7787-7794. lewis, a.; bumpus, j. a.; truhlar, d. g.; cramer, c. j. journal of chemical education 2004, 81, 596-604. short, g. d.; bishop, e. analytical chemistry 1965, 37, 962-&. tye, j. w.; darensbourg, m. y.; hall, m. b. inorganic chemistry 2006, 45, 1552-1559. o'hagan, m.; shaw, w. j.; raugei, s.; chen, s.; yang, j. y.; kilgore, u. j.; dubois, d. l.; bullock, r. m. journal of the american chemical society, 133, 1430114312. evans, d. j.; pickett, c. j. chemical society reviews 2003, 32, 268-275. chen, s.; raugei, s.; rousseau, r.; dupuis, m.; bullock, r. m. journal of physical chemistry a 2011, 114, 12716-12724. kanan, m. w.; surendranath, y.; nocera, d. g. chemical society reviews 2009, 38, 109-114. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset exploring user perceptions of book theft and mutilation: a case study rajesh kumar sharma librarian fatepur high (h.s.) school pailan college of management & india technology, kolkata, india abstract libraries serve as organized repositories of knowledge and resources, offering access to a wide range of materials in various formats to a defined community. this paper delves into the concept of libraries, emphasizing their role in providing both physical and digital resources to users. libraries, whether physical structures or virtual spaces, house an array of materials, including books, periodicals, digital media, and more, catering to diverse information needs. the historical roots of the term "library" can be traced to latin and greek origins, with derivatives like "bibliothèque" in french, symbolizing the idea of a bookcase and library in modern languages. one of the challenges libraries face is the intentional damage, defacement, or theft of materials, known as mutilation. mutilation encompasses acts such as tearing covers and pages, cutting out content, and removing labels or bookplates, all of which deplete library resources. the motives behind such actions vary, ranging from a sense of entitlement to financial reasons or disagreements with the library's collection choices, and even malicious intent. this paper presents a case study focused on user attitudes toward book theft and mutilation within a management college library, shedding light on the perceptions and behaviors surrounding these issues. keywords: library, resources, book theft, mutilation, user attitudes, management college. introduction “a library to modify the famous metaphor of socrates, should be the delivery room for the birth of ideas a place where history comes to life” (norman cousins) a library (from french "librairie"; latin "liber" = book) is an organized collection of resources made accessible to a defined community for reference or borrowing. it provides physical or digital access to material, and may be a physical building or room, or a virtual space, or both.a library's collection can include books, periodicals, newspapers, manuscripts, films, maps, prints, documents, microform, cds, cassettes, videotapes, dvds, e-books, audiobooks, databases, and other formats. libraries range in size from a few shelves of books to several million items. in latin and greek, the idea of bookcase is represented by bibliotheca and bibliothēkē (greek: βιβλιοθήκη): derivatives of these mean library in many modern languages, e.g. french bibliothèque.5 odlis described mutilation as “damage, defacement, or destruction of library materials inflicted intentionally, rather than accidentally, including tearing covers and pages; cutting out illustrations or passages of text; and removing labels, bookplates, protective covers, date due slips, etc.-all actions that drain library resources. the motives for such acts range from an attitude of entitlement, to monetary concerns (libraries generally charge for photocopying), to disapproval of the library's collection development decisions, and outright malice”. 6 this paper is a case study which examined the users attitudes to book theft and mutilation in management college library. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset objective:  distribution of questionnaire  frequency of library use  purpose of library visit  chances of being caught  causes of book theft or mutilating books  opportunity time for stealing and mutilation  method adopted for book theft or mutilating  is library book theft or mutilation normally wrong scope and limitation the present study covers the students, staff and faculty of library and documentation centre,pailan college of management & technology. sector-i phase-i. bengal pailanpark.joka., kolkata-700104.the college has almost 3,000 students. college library has over 16,500 books, journals and other resource materials. pcmt library provide delnet online journal for user. methodology used for data collection data on access and utilization of information resources was collected through a questionnaire designed for the purpose. the survey method was employed to collect the required data. a detailed questionnaire was prepared for this purpose and in order to enhance the validity and reliability of the questionnaire, experts in the field of library science, psychology and statistics were consulted and were requested to review the questionnaire critically. questionnaire was revised based on the suggestions. the study was limited to the user the library of pailan college of management & technology (pcmt). total of 160 questionnaires were distributed to collect the primary data. 135 questionnaires were received. collected data were analyzed. discussion table 1: distribution of questionnaire particulars readers questionnaire distributed 160 questionnaire received 135 table 2: frequency of library use frequency of library use no. of respondents % everyday 65 48.14 once in a week 35 25.94 once in a month 31 22.96 infrequently 04 02.96 table 2 represents frequency of library use. 65 respondents everyday use library. 35 respondents once in a week use library. 31respondents once in a month use library.04 respondents infrequently use library. table 3: purpose of library visit purpose of library visit no. of % mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset respondents education 102 75.55 entertainment 022 16.29 sports 00 00.00 other 011 08.16 table 3 shows purpose of library visit. 102 respondents visit library for education purpose. 022 respondents visit library for entertainment purpose and so on. 4 table 4 : chances of being caught chances of being caught no. of respondents % 2 out of 4 25 18.52 2 out of 20 47 34.82 2 out of 200 63 46.66 table 4 displays chances of being caught. according to 25 respondents, 2 out of 4 chances of being caught.47 respondents, 2 out of 20 chances of being caught. 63 respondents, 2 out of 200 chances of being caught.1 table 5 : period in which stealing and mutilation are committed period in which stealing and mutilation are committed no. of respondents % 10.00am-12.30pm 27 20.00 12.30pm-3.00pm 62 45.92 03.00pm-5.30pm 46 34.08 table 5 discloses that between 12.30am – 3.00pm mostly stealing and mutilation are committed. after that stealing and mutilation are committed between 03.00pm-5.30pm and so on. table 6: causes of book theft or mutilating books causes of book theft or mutilating books no. of respondents % the price of the book is very high 24 17.78 do not have enough facility of xerox 25 18.52 do not consider the need of others 49 36.29 unconsciousness about the importance of books 18 13.34 steal or mutilate books as expression of hostility toward the library 19 14.07 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 6 shows that 24 respondents think that the price of the book is very high is the causes of stealing or mutilating books. 25respondents think that do not have enough facility of xerox is the another causes of stealing or mutilating books. table 7: preventive measure preventive measure no. of respondents % provision of xerox facilities 44 32.59 cooperative staff 25 18.51 create consciousness among user 30 22.23 strong rules about steeling and mutilation and throughout checking 36 26.67 table 7 revealed that provision of xerox facility, strong rules about steeling and mutilation & throughout checking, create consciousness among user and cooperative staff can prevent book theft or mutilating. 2 table 8: method adopted for book theft or mutilating method adopted for book theft or mutilating no. of respondents % tearing of important pages 60 44.46 throwing books out of the window 42 31.11 removal of due date slip from borrowed book to un-borrowed one 26 19.25 other 07 05.18 table 8 reveals that 60 respondents identified that tearing of important pages is the main method adopted for book theft or mutilating. beside this removal of due date slip from borrowed book to un-borrowed one is the another method of book theft or mutilating and so on. table 9 : is library book theft or mutilation normally wrong is library book theft or mutilation normally wrong no. of respondents % yes 112 82.96 no 016 11.85 no opinion 007 05.19 table 9 discloses that most of the respondents think that library book theft or mutilation normally wrong. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset conclusion the problem of book theft and mutilation of documents held in libraries is not new. the first incident of theft from a library can be traced back to persian conquerors removing papyrus rolls from an egyptian library in 539 bc. 3 the problem is growing day by day. ranganathan (1970) through his guiding principles of library services contained in his five laws of library science, pointed out the usefulness and importance of the reader to any library. book theft and mutilation of documents affect the library services. the major findings of this study are below  65 respondents everyday use library. 35 respondents once in a week use library. 31respondents once in a month use library.04 respondents infrequently use library.  102 respondents visit library for education purpose. 022 respondents visit library for entertainment purpose and so on.  according to 25 respondents, 2 out of 4 chances of being caught. 47 respondents, 2 out of 20 chances of being caught. 63 respondents, 2 out of 200 chances of being caught.  between 12.30am – 3.00pm mostly stealing and mutilation are committed. after that stealing and mutilation are committed between 03.00pm-5.30pm and so on.  24 respondents think that the price of the book is very high is the causes of stealing or mutilating books. 25respondents think that do not have enough facility of xerox is the another causes of stealing or mutilating books.  provision of xerox facility, strong rules about steeling and mutilation & throughout checking, create consciousness among user and cooperative staff can prevent book theft or mutilating.  60 respondents identified that tearing of important pages is the main method adopted for book theft or mutilating. beside this removal of due date slip from borrowed book to unborrowed one is the another method of book theft or mutilating and so on.  60 respondents identified that tearing of important pages is the main method adopted for book theft or mutilating. beside this removal of due date slip from borrowed book to unborrowed one is the another method of book theft or mutilating and so on.  most of the respondents think that library book theft or mutilation normally wrong. suggestions • proper orientation should be given to users of the libraries. • affected libraries should launch campaign against user delinquency; libraries should engage more trained security personnel. • the photocopying services of the library should be subsidized. references alafiatoyo, bo. 1987. students attitudes to book theft mutilation in a university library. v12(1) pp.19-37 opaleke, js, raja, aa, folorunsho.2004. anexamination of mutilation and theft cases in nigerianacademic and publiclibraries. v7 pp. 271-279 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 2; march april 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset stewartm, j a. 1999. how much is too much? a case study to determine whether the cost of book loss at the geology library at the university of north carolina at chapel hill is greater than the cost of an electronic security system.https://cdr.lib.unc.edu/record;jsessionid=3884a78a76153c3cd7046649394b89a6?id=uuid %3a3a290cec-e285-4061-9d75-2ac9b004ab30 visited on 23.10.2012 4.chandra, s. 2011. efficient use of departmental libraries with special reference to narula institute of technology, india international journal of library and information science v 3(6), pp. 116-119 http://en.wikipedia.org/wiki/library visited on 23.10.2012 http://www.abc-clio.com/odlis/odlis_p.aspx visited on 23.10.2012 mailto:topacademicjournals@gmail.com https://cdr.lib.unc.edu/record;jsessionid=3884a78a76153c3cd7046649394b89a6?id=uuid microsoft word 1.docx academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 48 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the rotating wave theory: a unifying theory of physics bill christie and benny wong architect aibc oaa port coquitlam, british columbia abstract: the michelson-morley experiment was a famous experiment that attempted to detect the motion of the earth through the luminiferous aether. the experiment was unsuccessful, and this led to the development of the special theory of relativity by albert einstein. keywords: michelson-morley experiment, luminiferous aether, special theory of relativity, length contraction, time dilation, lorentz transformations 1. introduction it is well known that in 1887 a.a. michelson and e.w. morley could not detect any luminiferous ether by detecting a path length difference between light transmitted in the direction of the earth’s travel through the stationary ether and perpendicular to that direction by a fringe shift. in 1889, h.a. lorentz suggested that the null result of this famous experiment might be due to an actual physical length contraction of the interferometer as measured in the direction of its motion of the earth’s orbit. according to lorentz, the length contraction was merely due to an electrodynamic effect on physical processes within the electron particle make-up. lorentz also suggested that such physical processes had a cyclical function, or local time, which must slow down or dilate in conjunction with their length contraction. however, the reasons for local time dilation and length contraction as suggested by lorentz required a complicated and unconvincing model of an electron to be composed of many like charges bound by a nonelectric force infinitely strong at the centre. ironically, the lorentz transformation equations of time dilation and length contraction survived to form the basic math of a much more acceptable, although revolutionary, theory put forth by albert e. einstein in 1904. albert e. einstein’s special theory of relativity was much more acceptable because it was simple and universally consistent. his special theory stated that all laws of nature, including mechanical as well as electromagnetic field laws, must be invariant with respect to the lorentz transformations. he proved the consistency of his theory by applying the principle of equivalence to the special theory and created his general theory of relativity, which in turn correctly predicted the influence of a gravitational field on light. also in 1904, albert einstein demonstrated that light behaved as individual particle – like packages of energy called photons in order to explain the photo-electric effect. thus, in a quasi-corpuscular theory akin to that of sir isaac newton, einstein stated that the nature of light must have a wave-particle duality. however, matter was still considered to be only particle-like until twenty years later when louis de broglie suggested that matter as well as light might have a dual, wave-particle nature. both the lorentz and einstein interpretations of the michelson– morley experiment required that the interferometer be “particle-like" only. i began to wonder how the michelson morley experiment might have been interpreted had the dual, wave-particle nature of matter been established prior to this famous experiment. furthermore, i considered that matter might mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 49 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset simply be a localized wave and that its particle-like nature is simply a phenomenon derived of its localization.according to einstein’s definition of simultaneity there is no need for a physical length contraction of the michelson–morley interferometer. however, if as lorentz contended, the length of the interferometer did indeed contract in the direction of its motion, then there could not be any fringe shift detected on the interferometer and real time could remain constant. one could disagree with einstein’s assumption that his operational definition of simultaneity is valid in any inertial reference frame and revert back to the nineteenth century classical view of light which accepts such a definition as “valid only in the rest frame of ether” (em vacuum field). my alternative conclusion about the experiment, coupled with the fact that matter is localized energy and that energy in the form of electromagnetic waves is indeed transmitted as light, compelled me to find a basic form of matter: a particle equivalent to a localized electromagnetic wave with an innate time cycle that would explain the fact of time dilation and a configuration that would require its own physical length contraction. most other forms of matter that arise out of the em vacuum field would only be variations or further developments in the evolution of this principle form of matter which is from hereon referred to as the rotating wave (or rw for short). the em vacuum field is here stated as a universal reference frame only to a degree of which our perception is capable. the intent of this work is, therefore, to explain by the em vacuum field, the creation of the principle form of matter and the phenomena of relativity, gravity, and quantum mechanics beginning with two postulates which compare with those of einstein’s theory as rephrased by casper and noer in the evolution of physics on p. 330: i. the principle of relativity according to the rotating wave: no physical measurement can distinguish one inertial reference frame from any other inertial reference frame because such distinction is obviated by changes in the actual physical time cycle, length, and mass of a particle with respect to that particle’s motion relative to the stationary, em vacuum field. such changes are illustrated by the rotating wave. ii. independent of the motion of the light source, only wave fronts of light which proceed in a straight line with respect to a euclidean universal reference frame (defined by the stationary em vacuum field) always propagate in empty space (the vacuum state of the em field) with a definite velocity c relative to that universal reference frame. other wave fronts which do not proceed in a straight line, propagate with an angular velocity such that all wave fronts remain planar. from the two postulates above, i can simply state that the null result of the michelsonmorley experiment is due to an actual physical length contraction of the interferometer in the direction of its motion. the actual physical time cycle of the whole interferometer apparatus slows down in unison and therefore time is not the culprit. the two postulates above also provide an explanation to the outcome of another experiment: the low rate of decay of mesons entering the earth’s atmosphere is due to a combination of some degree of actual physical length contraction of the earth’s atmosphere and some degree of actual physical slowing of the time cycle decay of mesons. 2. the electron as a basic form of matter the electron and its antiparticle, the positron, elegantly fit the requirements of this basic form of matter. the electron rw complies with the universal laws of electromagnetism and the previous two postulates. by doing so, it inherently explains relativity, mass, and quantum mechanics. according to the electromagnetic theory of light, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 50 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the change in the electric field of the photon induces a magnetic field and, conversely, the change in the magnetic field induces an electric field. these changes are made with particular direction at the speed of light through the electromagnetic field, which was once labelled as “ether”. in order to exist, the photon must move forward through this electromagnetic field such that the changes in both the electric and magnetic fields induce each other. the photon cannot be at rest with respect to the electromagnetic field and therefore does not have any rest energy or rest mass. however, there are two types of motion: translational (linear) and rotational (angular). we perceive the photon to move forward through space in translational motion. if the two vectors of the electromagnetic wave of a photon could be brought to spin, not as in the case of a circular polarized wave, but as in the case of the electron model shown in figures 1 and 2, then it might create a magnetic dipole and an electric monopole. figure 1: sectional plan view of counter clockwise rotating (spinning) electron wave inducing magnetic lines of force b (as arrows coming up from the page) and electric field e. figure 2: sectional side view of spinning electron wave inducing magnetic dipole and electric monopole. at some small radius (very close to the axis of spin) where the velocity of the rotating wave is less than c, the direction of the magnetic and electric fields might reverse with respect to their cross product to allow for the singular connection between the north and south poles. just as the magnetic field of a photon changes in translational motion, thus inducing an electric field, so does the magnetic field of the electron change in rotational motion thus inducing the electric field of the electron. likewise, as in the photon, the change in the electric field of the electron induces the magnetic field of the electron. in compliance with the electromagnetic theory of light, the electron rw (and likewise the positron) is nothing but one half of a gamma photon brought into rotation by a binding energy equivalent to another half of a gamma photon. this is confirmed by experiment. if a gamma ray mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 51 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset is brought under enough localized energy, an electron-positron pair will be created. all of the energy will be conserved as rest mass and kinetic energy of the particles. when the electron and positron are then brought together in annihilation in free space, they produce two photons whose total energy is equal to that of the original photon and the localized energy from which the particles were created. when positive and negative charged particles are oscillated towards each other they will induce an electromagnetic wave which spreads out in every direction except the path of their oscillation. similarly, two photons are emitted in opposite directions during the annihilation of an electron-positron pair in free space. note that the counter-clockwise spinning electromagnetic wave which is shown as a dark straight line in figure 1 is actually a sectional view of a planar wave front with the maximum (or nodal) electromagnetic magnitude. other lines representing lesser magnitudes are not drawn for the sake of simplicity. also note that the speed of the wave must be greater at distances further from the centre of spin. as noted in figure 2, the singular connection between the poles of the electron and thus the curved magnetic lines might be due to a reversal of the electric and magnetic directions with respect to the direction of rotation at very low speeds and thus in close proximity to the axis of spin. at a greater radius the rotating nodal wave front might be interpreted as a virtual particle blinking into existence with negative charge while at a lesser radius the rotating nodal wave front might be interpreted as a virtual particle of positive charge. the boundary between the reversal might not be so definite. furthermore, the reversed fields might provide a binding energy which sustains the speculated rotating wave of the rw. figure 3: photon wave existing in translational motion. it is not fully apparent how the originating electromagnetic wave of the photon, as illustrated in figure 3, is brought into rotation by a local binding energy. however, given a nodal planar wave front which extends to infinity in accordance with the wavicle, one can deduce that any curvature in the photon’s translational path will require a definite point of rotation for that wave front and thus an associated magnetic dipole along with a symmetrical electric field. therefore, any curvature in the photon’s path will immediately result in fermion type particles, albeit with negligible and short-lived mass. given sufficient and local binding energy, the curvature will result in the sustained electron and positron as illustrated in figure 4. figure 4: in this case the formation of the electron (left) and the positron (right), each with their own selfsustaining and rotating electromagnetic wave, conserves electric field (charge), magnetic moment, and spin angular momentum. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 52 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset one immediate variation of the foregoing concept of a rotating electromagnetic wave could be that which creates a magnetic monopole and an electric dipole. or perhaps the rotating wave might show that the electric and magnetic fields of light are merely two different directions of stress, distinguished from each other only upon the creation of the dipole of the electron. other immediate variations, such as the muon and tau fermions, could simply be created by the rotation of waves which have different frequencies than that of the gamma photon. virtual photons, gluons, and gravitons causing electrodynamic, chromodynamic, and gravitational interactions amongst particles might simply be the rotating waves of the particles themselves. however, any speculation of immediate or evolved variations of the rotating electromagnetic wave form will not be further discussed in this paper. 3. relative time (dilation) redefined according to the special theory of relativity, the spin of a moving electron, as measured by an outside observer, must be slower than the spin of a stationary electron. however, without regard to relativity, the angular velocity of an electron wavicle’s spinning electromagnetic wave must slow down as it gains translational motion simply because the speed of light remains constant at the same distance from its axis of spin. this is illustrated in figure 5. figure 5: cylindrical model of the vectors of the rw (spinning) electromagnetic wave of an electron with translational velocity v and spin 1/2. (0 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 53 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset at a certain distance r0 from the centre of the electron and midway between its magnetic poles, let us say that the electron wavicle’s electromagnetic wave is moving at a tangential velocity vr (here defined as the rotational velocity) about the center. if the electron is stationary (without translational motion), then the time it takes the electron wave to complete one cycle about the centre will be t 0 if the electron is given a translational motion of velocity v , then the new time it takes the electron wave to complete one cycle about the centre can be called t . the permeability 0 and the permittivity 0 of free space will remain constant about the same radius r0 from the axis of the electron’s rotation regardless of whether or not the electron is in translational motion. therefore the resultant rotational velocity vr of the electron wave must decrease as the translational velocity v of the electron increases in the direction of the axis of the electron’s spin. from figure 5. vr = (c2 v2)1/2 without translational motion (v = 0) and we have, 2 r 2 r t0 = = vr c with translational motion v 0 we get, 2 r 2 r t = = 2 2 1/2 vr (c v ) 1/2 2 v and therefore t = t0 1 c2 which agrees with the time dilation formula of the special theory of relativity. since this concept of the electron contains only a spinning electromagnetic wave, then it is only the electromagnetic wave that exhibits time dilation. furthermore, according to quantum mechanics, ionic and thus mechanical functions must slow down merely in response to the time dilation of the electron’s electromagnetic wave. therefore, real time does not slow down according to the special theory of relativity; rather, the fact of time dilation is due to the electron’s (and positron’s) spin of its electromagnetic wave coupled with the constant speed of light at a given radial distance from the axis of the electron’s rotation. 4. required length contraction the direction of propagation of an electromagnetic wave must always be at right angles to the direction of both its electric and magnetic fields. therefore, an rw with translational motion will have each rotating planar wave front reoriented such that each respective resultant velocity c , as previously shown in figure 5, will be normal to the wave front. figure 6 shows a side elevation of an electron moving with a translational velocity v and viewed at an observed radius r = 0/2 . since the electric field of an electron must always point to the centre, then the rotating wave of a moving electron wavicle will be inclined from the normal axis of rotation of a stationary electron such that the rotating wave of a moving electron will trace a helical path through the electromagnetic vacuum field. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 54 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6: side elevation of moving electron wavicle with translational velocity v at an observed radius r = 0/2 from figure 6 we can see that for a given electric field at an observed radius r = 0/2 , is the length of the wavicle contracts in the direction of its motion by a factor of vr/c such that: v r 2 2 1/2 = and vr = (c v ) 0 c 1/2 v2 = 0 1 c2 which is the length contraction formula for the transformation laws of the special theory of relativity. since the equilibrium distance between wavicles is assumed to be ultimately determined by their electromagnetic fields, then the distance between rw’s should contract correspondingly in the direction of their motion. therefore, the required length contraction is due to the rw’s spin of its electromagnetic wave, coupled with the fact that the direction of propagation of an electromagnetic wave must always be at right angles to the direction of both its electric and magnetic fields. note that as indicated in figure 6, the magnetic poles of the electron are displaced from the line of the electron’s translational motion, thus inducing the required magnetic field of a moving field of a moving charge. at any one instance this displacement would be characterized by two polar cones: one extending out forward and one extending out backward from the direction of the electron’s motion. a stroboscopic detection of this polar cone by an apparatus similar to a cathode ray oscilloscope would prove the physical length contraction of the electron as required by the concept of the rw.figures 7, 8, and 9 further clarify how the configuration of the rw transforms when put in motion. figure 9 more clearly illustrates the forward polar cone (rear polar cone is hidden) and illustrates the induced, right-handed magnetic field. figure 7: stationary wavicle vr = c oblique elevation of stationary electron rw with magnetic lines of force b (electric field not shown here for simplicity) and nodal wave front spinning with tangential velocity c . (0 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 55 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 8: moving wavicle v r = (c2 v2)1/2 oblique elevation of moving electron rw with magnetic lines of force b and nodal wave fronts reoriented at an angle as previously illustrated in figure 6. figure 9: moving rw creating a right-handed magnetic field oblique elevation of moving electron rw with wave fronts of lessor field strengths shown as well as the nodal wave front (highlighted lines with arrows). this figure clearly indicates a right-handed induced magnetic field. 5. a definition of rest (energy) mass rest mass is localized energy without translational motion; therefore, according to the concept of the electron rw, the energy of rest mass called rest energy e 0 is simply the rotational energy er of the half-photon which is rotating in one spot, plus the binding energy eb which keeps the half-photon in that rotation. the half-photon has a kinematic rotational energy er = h /2 which is equal to the binding energy such that the electron’s total rest mass energy e0 = er eb = 2ere0 is thus equal to a whole photon’s energy h as given by planck’s constant h and the frequency of the photon . according to rotational kinematics, where er is the rotational energy, k is an assigned constant for the derivation of rotational inertia i , m0 is a non-relative mass of a symmetrical spinning object, and vr is the velocity of spin at the radius r 0 of the object, then e r = (1/2)km 0 v r 2 can be derived. since, according to the rw concept, all mass is assumed to be derived from electromagnetic waves, then the rotational energy and non-relative mass of the stationary rw can be equated in the same manner. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 56 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset by convention, k is assigned the value of unity for the wavicle, such that all objects are thus correctly allowed to have their rotational inertia computed as the summation of point wavicle masses at their respective radii. therefore, e r = (1/2)m 0c 2 for a stationary electron and a stationary electron will thus have a total rest energy e 0 = m 0c 2 . the rotational energy of a stationary electron can also be defined in kinematic terms by its angular frequency 0 and its angular momentum l0 such that er = 0l0 = 2 0l0 = h /2 , where 0 is the frequency of electron spin. since we know the values: h = 6.63 10 34 joule-sec. and l0 = 0.52723 10 34 joule-sec., then 0 = 2 which is as it should be because according to quantum mechanics the spin of the electron must be quantized with respect to the originating gamma photon. finally, since c = 2 r0 0 , then h = 4 r0m0c. 6. relative mass with respect to motion according to the foregoing figures 5 and 6, an electron with translational motion will have an angular momentum pr = mvr = m(c2 v2)1/2 which according to the conservation of momentum is equal to the angular momentum p0 = m0c of a stationary electron. a relative mass m is defined with respect to its translational velocity v because the configuration of the mass as indicated in figure 6 and 9 changes with respect to v . note the increased flux or density of electromagnetic lines as illustrated in figure 9. therefore: 1/2 2 v m = m0 1 c2 (06) which agrees with the special theory of relativity where m is the relative mass with respect to translational motion. the total energy e of an electron must be the sum of its rest energy e) plus its kinetic energy k due to its translational motion such that: e = e0 k and since x k =fdx=mc2 m0c 2 0 while f is constant force over a distance x to give the electron translational motion, then e = mc2 . furthermore, the translational momentum p v and resultant momentum p of a moving electron rw can be vectorially related such that: p2 = pv 2 p0 2 and then multiplying by c2 m2c4 = pv2c2 m02c4 hence e2 = pv2c2 e02 (08) according to the rw concept, the correct relative mass and its associated momentum and energy have been derived with respect to translational motion regardless of the special theory of relativity because real time has been kept constant. (0 (0 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 57 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 7. an electromagnetic wave theory of gravity according to the wavicle, free space or vacuum is defined as the electromagnetic ether field in which light and matter waves are able to propagate. the basic premise of this theory of gravity is that the binding energy eb holds the classical wave of the rw in rotation by affecting the permittivity and permeability of free space. thus any other incidental wave will similarly be affected by the binding energy of the rw, although indirectly and to a lesser degree. figure 10, illustrates a passing test photon with a given huygen’s wavelet at distance r from the center and midway between the magnetic poles of a single stationary electron rw. regardless of the rw charge, the wavelet will be permitted to go at the velocity u1 = pu = 2 pr 0 either in the same or opposite direction of the rotating wave. figure 10: vectorial description of rotating wave showing resultant gravitational acceleration of wavelet. while u is the tangential velocity of the rotating wave at distance r , and 0 is the frequency of the rw’s rotation, p is a variable dependent upon the strength of the vector field generated by the rw at radius . however, as illustrated in figure 10, changes with respect to time and direction and therefore the photon wavelet would also be accelerated by the amount: du u2 a0 = p = p dt r in other words the plane of the passing test photon or electromagnetic wave would be bent to some degree by the rotating wave and would account for the phenomenon of gravity. obviously, according to the rw concept, a huygen’s wavelet closer to either of the magnetic poles, but at the same distance from the centre of the electron rw, will experience less gravitational acceleration. however, the second premise of the theory of gravity is that uniformity of gravitational acceleration at a constant distance about a spherical mass is simply due to the fact that such mass is composed of many rw’s at various angles of spin and random motion. therefore, while the electron has a gravitational field severely distorted by its magnetic poles, larger non-elementary particles of matter have more uniform gravitational fields at a given radius. while p is the real constant assigned to the gravitational acceleration of the basic particle, a modified p1 = k1p can be assigned in a limiting case to the more uniform gravitational fields of larger particles at a given radius. however, as p1 is only an average value of p , then it can be renormalized to p for simpler calculations that follow. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 58 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset since the wavicle must comply with gaussian law at distances beyond which charge is screened, then the macroscopic laws of gravity must be able to be deduced in the same way. gauss’s law gives a connection between the flux e for the gaussian surfaces ds and the net charge q enclosed by the surface: 0 e ds = q where e = e ds and e is the electric field strength; 0 is the universal permittivity constant. similarly, a universal constant c3/(gh) , which can be proved by deduction, operates on the gravitational field strength a0 and its surface integral such that: c3 u2 a0 dz = or gh r 1 c3 = ds p gh since h = 4 r0m0c and the surface integral is a sphere, then: 1 c3 2 c2r2 = 4 r = (11) p gh gr0m0 and from above 2 2 2 2 u gm0 r0 u gm0 r0 c r a0 = p = 2 2 = 2 2 2 and thus r r c r r c r0 r gm0 r a0 = 2 r r0 however, according to the general theory of relativity, our clocks run faster at higher heights and therefore, our acceleration at higher heights is actually greater than it appears to be such that: a r0 r rateof real time = where = a0 r r0 rateof perceived time and therefore a = gm 0/r 2 , where a is the apparent acceleration and m0 is the apparent constant mass. 8. the principle of equivalence and the gravitation of matter albert einstein predicted correctly by the "principle of equivalence" in his general theory of relativity that matter would gravitate or bend light and slow down time. he found a deeper significance than mere coincidence that a gravitational reference system could be made equivalent to a uniformly accelerated reference system because it enabled him to extend his special theory of relativity to his all-encompassing general theory. however, according to the foregoing electromagnetic wave theory of gravity, light is simply bent by the rotating wave (or matter wave) of the rw. (1 (1 (1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 59 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset since the rotating wave is itself light, then the path of that rotating wave will be bent in the same manner by another rw; thus two rws each other by such gravitation. the gravitation of anrw by a larger mass m centered at point q is illustrated by figures 11 and 12. figure 11: sectional plan view of rotating wave front centered at distance r from mass m centered at q . figure12: sectional side view of rotating wave front of rw centered at distance r from massm centered at q. since the motion of the electron rw is limited to the direction of the axis of its spin, thenthe acceleration of the rw as illustrated in figures 11 and 12 need only be considered in the direction of the axis of its spin. in figure 11 the rotational velocities of the rw’s wave front are indicated as arrows ( s1 and s2 ) coming up from the page and the wave front lies in the plane of the page. note that at different distances along the same radial direction from q , the ratio of velocities qs1/(qs2) = r1/r2 = r1/r2 and, therefore, the instantaneous effects of both the rw and larger mass m on the permittivity and permeability of free space are consistent. however, the lines drawn radially from point q reveal different rotational velocities at a constant radius r1 where the permittivity and permeability of free space is affected to some degree by the larger mass m. since the permittivity and permeability of free space is also instantaneously affected by the rw, such that the observed rotational velocity of the rw increases in direct proportion to its observed radius of spin, then the wave front of the rw must remain planar. however, as illustrated in figure 12, the rw’s planar wave front will be bent mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 60 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset instantaneously as it rotates about its axis of spin which is directed towards q . although the wave front of the rotating wave remains planar, its inclination with respect to its axis of spin increases as the wave rotates and the rw is thus accelerated to point q . the rw equally shows by huygen wavelets how light is gravitated or bent and thus how matter is gravitated. also, the electromagnetic wave theory of gravity shows by huygen wavelets how light is permitted to go at greater speeds at distances further from the centre of the rw. again, since the rotating wave of the rw is light, then the velocity of that rotating wave will be affected in the same manner by the proximity of another rw. hence the spin frequency of the two rws in close proximity will be less than that of two rws separated by a greater distance. therefore, the electromagnetic wave theory of gravity enables a reinterpretation of the general theory of relativity by predicting, first, the gravitation and slowing down of light and, second, the gravitation and slowing down of the time cycle of matter. the “principle of equivalence” can be explained by the equivalence of light and matter according to the concept of the rw. 9. graphical derivation of the rk and gk in the general theory of relativity tensor math forms the mathematical foundation upon which the laws of einstein’s general theory of relativity are defined. the rotating wave also shows how tensor math allows for the calculation of intrinsic curvature of space-time. according to relativity, it must be just as valid in one reference frame to analyze the path of free falling light influenced by the gravitational field of a stationary mass in order to describe the curvature of spacetime as it is to postulate in another reference frame the curvature of space-time by the mass energy density tensor of an attracting mass which is in motion. furthermore, according to the above 8. the principle of equivalence and gravitation of matter, the analysis of the path of free falling light in the the rotating wave must be equivalent to describing the gravitational field about a stationary attracting mass. when there is an attracting mass, gravity will accelerate a free falling rotating wave. the axis of rotation of the rotating wave will of course be in the direction of motion towards the attracting mass. as the forward motion increases, the planar wave fronts of the rotating wave will incline as illustrated in figure 6. while potential energy is converted into kinetic energy (as per e2 = pvc 2 e 0 2 above), extra work will also be done and thus energy expended on the rotating wave to incline or bend the rotating planar wave fronts. this is just like the bending of light by mass in the above 7. an electromagnetic theory of gravity. this extra change in energy is thus associated with the slowing down of the time cycle of the rotating wave regardless of whether it is in free fall motion or not. the fact is that mass does slow down time (“clocks run faster at higher heights”) and a stationary rotating wave thus must slow down in the presence of an attracting mass. when there is no attracting mass present, the radius r0 at which the rotating wave rotates at velocity vr = c v stays constant as per figure 5. when there is an attracting mass present, the radius at which the rotating wave rotates must increase as its time cycle of rotation slows down. this increase in the radius of the rotating wave will be referred to as the spiral condition. note the velocities of the rotating wave in one reference frame must correspond to those velocities of the mass energy density tensor of an attracting mass in another reference frame. whereas in the general theory of relativity the attracting mass is defined by the mass energy density tensor and related to the reimannian curvature of space-time, the following derivation of the r kl is directly deduced by first defining the path of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 61 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset rotating wave as a geodesic on a generated surface and then second deriving the intrinsic curvature of that surface. consider the dashed helical path of the rotating wave as illustrated in the previous figure 13. the helical path can be defined by a time derivative of the position vector posc = posv post posv is the vector in the forward moving translational motion of the rotating wave and same direction of rotational axis. post is a rotor and is the vector in the purely rotational motion. if the velocity vector vt is greater than zero (or less than zero), then the velocity vector c of the rotating wave with constant speed of light will spiral outwards (or inwards): figure 13: rotating wave of the electron (fermion). position vectors posc = posv post , where post rotates. velocity vectors, c = vv vr vt . dposc dposv dpost det dpost c = = = vv post et dt dt dt dt dt vectorially: c = vv vr vt note vectors are not embolded, but implied with base vectors. note: c2 = vv2 vr2 vt2 and thus dc/dt = 0 = vv av vr ar vt at . also the base vectors for the riemannian space time located along the light line are defined by the partial derivative of the position vector: e = pos c/ x = pos v/ x post / x = pos c, = pos v, post , thus ecc = e u = (posv, )u (post , )u = dposv/dt dpost /dt . thus the path of the rotating wave with constant speed of light is defined by five vectors in our familiar three dimensions of space by: c = vv vr vt of which vv = vx vy vz . the spiral helical path also lies within a generated surface that can be described in riemannian five dimensional space-time with c = e u = evu v eru r etu t (17) of which again evu v = exu x eyu y ezu z (with implied einstein summation on ). (1 (1 (1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 62 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the “light–line” of the rotating wave is defined as the geodesic where c = vv vr vt and the magnitude c (of c = ecc ) is kept constant at the speed of light. so, vv, vr , and vt vary while c (of c = ecc ) is kept constant. vv is the forward (translational) motion of the rotating wave along the direction of the axis of rotation. vr is the purely rotational motion of the rotating wave. vt is the velocity of outward radial expansion of the light–line such that the light–line traces a spiral helical path. to be clear, at any point on the light–line: c = e cc = e u = v v v r v t and the base vector e c varies while the magnitude c is kept constant. also, note the spiral helical surface extends radially from the centre of axis of spin and is normal to the wave front. note that in the spiral condition: c = vv vr vt whereas before the simple helical (cylindrical) form of the rotating wave in accordance with the special theory of relativity, vt = 0 and thus c = vv vr as illustrated in figures 5 and 6. note v = vv and the subscript is added to clarify the forward velocity. clearly, vt has been added to the rotating wave model to allow for the added spiral form (or condition) in accordance with the general theory of relativity. we now have the spiral plus helical conditions in which all possible directions of motion are allowed for the rotating wave. it is allowed to rotate, move forward, and now also move outward (or expand). it will be seen and further expounded in the r k derivations that the rotational velocity vr is of course greater at greater radii. likewise, the u components will be greater at greater radii. note also that the generated spiral helical surface can equally be defined at any angle about the rotating wave’s axis of spin, just as the planar wave fronts are rotated and arrayed around the axis of rotation in figure 9. likewise, the “light–line” as defined above can be rotated and arrayed infinitely around the axis of rotation. with no expansion and magnitude vt = 0 (of vt = etvt ), this array would take the shape of a cylinder which has no intrinsic curvature. even with a constant expansion speed vt and constant forward motion vv this array would form the shape of a cone that also has no intrinsic curvature. (a cone can be cut down its length to its point and laid out flat just as a cylinder can.) if the expansion speed vt increases or the forward motion v v decelerates, then the cone shape would curve and take the shape of a “flute” (or horn or bell) which would then of course have intrinsic curvature. so, in order to have intrinsic curvature on this array, the rotating wave must have forward motion and radial expansion plus acceleration (or deceleration) in either the forward motion or radial expansion or both. note also that the e ru r certainly corresponds to the rotational velocity vr of the rotating wave while c = ecc corresponds exactly to c = vv vr vt , so the e vu v = e 1u 1 e 2u 2 e 3u 3 must as a result correspond to the forward (translational) velocity of the rotating wave. while any helical surface is extrinsically curved, it can be shown that the helical surface of the rotating wave does not necessarily have intrinsic curvature. if there is no attracting mass, then the axis of spin will not change and the above generated helical surface will be intrinsically flat. such a helical surface when unwrapped from its helical path will become extrinsically flat. when there is an attracting mass, gravity will accelerate a free falling rotating wave and also cause it to spiral outwards. the combination of spiral and helical path will create intrinsic curvature. the helical path illustrated in figure 13, can also be described by: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 63 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset erur = e1u1 e2u2 e3u3 e4u4 = esus c such that the curvature invariant – (ur ) 2 = giju iu j with the use of the metric tensor and einstein’s summation convention of summing on repeated indices. according to minkewski space-time coordinates, u4 = ic and (u4)2 = c . note that the tensor relationship, which is graphically illustrated by the rw, can be more fundamentally described by the equation: c2 = biju iu j in which b ij is an equally valid metric tensor and now u4 =ur . this enables us to eliminate the imaginary component i and construct the bij from conventional base vectors. from here on the summation convention will be used implicitly and the bkl = gkl = ek e such that c2 = gklu ku to keep things simple. at the conclusion of the following derivation of rk and thus gk , one can then compare the rotating wave with that of the minkewski space-time coordinate system and the mass energy density tensor t k . general surfaces – curvature calculation – rk the intrinsic curvature of the spiral helical surface can be calculated by the reimannian curvature tensor r ik n and sufficiently by the ricci tensor r k = r k n which is the contraction of the curvature tensor. note vectors are not embolded, but implied with base vectors. rikn = t ni,k t nk,i tsint sk tsknt si = [t ni,k tsknt si ] [t nk,i tsint sk ] note: rc = curvature due to the rotational motion of the wave. further derivation: e ,nk = rc,ku unc 2 rcu ,kunc 2 rc,ku un,kc 2 (24) and by applying the chain rule again: e ,nk = rc,c( xc/ xk )u unc 2 rcu ,c( xc/ xk )unc 2 rc,ku un,c( xc/ xk )c 2 and thus: e ,nk = rc,cuku unc 3 rcu ,cukunc 3 rcu un,cukc 3 and e ,kn = rc,cunu ukc 3 rcu ,cunukc 3 rcu uk,cunc 3 note wherever you have ukun , then for rk the terms will obviously commute and thus the first two terms are discarded: rk = (e ,nk e ,kn )en = rcu c 3(un,cuk uk,cun )en (27) again using the chain rule as above: rk = rcu c 4(anuk akun )en (28) note: c = e cc = e nu n is always perpendicular to cr c = de c/dt and thus the scalar dot product between r c and c = 0. thus for the rotating wave: rk = rcauku c 4 (29) while a = acceleration of the u velocities and the ricci scalar r = gk rk = rcac 2 (30) and 1 rca 2 1 gk = rk gk r =2 uku c gk (31) 2 c 2 (1 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 64 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset which compares somewhat with the einstein tensor gk = 8 ktk where the mass energy density tensor tk = ( p)uku gk p has been written. also, the scalar (32) g = gk gk =rcac 2 (33) note again, we are deriving the surface curvature where the light line follows the path of the wave which is going at velocity c at certain radii from the axis of spin. that light– line spirals out and the angular velocity thus decreases, slowing down the time cycle of the rotating wave. this is relevant to the apparent expansion of the universe and the apparent slowing down of time. without this expansion and slowing of time, there can be no intrinsic surface curvature of the path of the rotating wave and thus no gravity. an electromagnetic wave theory and thus summing on n and plus reorganizing: rk = [t nn,k tsknt sn ] [t nk,n tsnnt sk ] (20) now let a vector: a= es a s = e ,k = e / xk and another vector b= es a s = el, j = e / x j thus: rikn = [a,nk (es,ken )as ] [b,ni (es,ien )bs ] and : rikn = [esen a,sk (es,ken )as ] [esenb,si (es,ien )bs ] rikn = [a,k b,i ]en = (e ,ik e ,ki )en summing on i and n , we thus have another mathematical formula for the ricci curvature (2 tensor rk : rk = (e ,nk e ,kn )en for any form of curved continuous surface. it is interesting that it looks a bit similar to the faraday tensor fk = a, n k a, k n . rotating wave position vectors and curvature calculation – rk since ec and e lie within the surface c = ecc = e u then by the chain rule: e ,n = e / xn = e / xc( xc/ xn ) = ec/ x ( xc/ xn ) = ec/ xc( xc/ xl )( xc/ xn ) = ec/ xt ( xt/ xc)( xc/ x )( xc/ xn) = (dec/dt) c 1(ece )c 1(ecen)c 1 (2 = (dec/dt) u unc 3 = rcu unc 2 (02 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 65 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of gravity, the binding energy ( eb ) of the rotating wave affects the permittivity and permeability of space which in turn causes incidental waves to slow down and accelerate towards the attracting mass. thus the slowing of time, spiral expansion of the light–line, and the gravitational force all go hand in hand to explain the expansion of the universe from the quantum mechanical level. the binding energy given up through the interaction of rotating waves thus appears to go into the background radiation. line eq. (29) is very telling. if a = 0 or a is perpendicular to rc , then there will be no intrinsic curvature. in order to get intrinsic curvature, we need spiral expansion of the helical light line plus the forward motion and use of riemannian geometry. a spiral light line of a stationary rotating wave would indeed spiral, but remain on a flat plane. a helical light line without spiral expansion would remain on a cylindrical surface that has no intrinsic curvature. a helical light line with spiral expansion could trace a path on a cone which again has no intrinsic curvature. if the radial expansion is increasingly faster than the forward motion, then the resultant helical spiral light line can be infinitely arrayed around the axis of wave rotation (albeit with with varying amplitude accounting for quantum mechanics) and the array will form the shape of a “flute”. a flat space “cone” tangent to the “flute” would represent a local inertial reference frame. thus according to the rotating wave, the requirement for intrinsic curvature and hence gravity is a range between two extremes: the accelerating spiral and constant forward motion or constant spiral and accelerating forward motion. note the spiral condition (or form) of the spiral helical rotating wave immediately suggests the slowing down of time and expansion of matter. where the rotating wave had a rotational velocity vr before at lessor radius of rotation, the time cycle of the rotating wave slows down in a gravitational field and vr is now at a greater radius. thus the rotating wave of the rw has a built-in function that manifests itself in the apparent slowing down of time and expansion of the universe. the spiral condition immediately obviates the need for the cosmological constant. according to the rotating wave, the cosmological constant is not required because the spiral helical rotating wave is already slowing down and expanding. in order to maintain the law of energy conservation, the 1 8 g gk = rk gk r = 4 tk (34) 2 c is sufficient. 10. an explanation of quantum mechanics the concept of the rw simply explains why plank’s constant h is intimately included and quantized in the characteristics of the electron and all cyclical functions. according to the definition of rest (energy) mass, h automatically enters any equation of matter. also, since the two nodes of the rw rotate, the effect of their electromagnetic and gravitational field strengths on an adjacent particle must vary in a cyclical fashion. therefore, an orbiting electron rw must have a distance from the nucleus which undulates in direct correspondence to the electron’s spin. relativistic effects of the orbiting electron and nuclear particles would of course further define the path of orbit. furthermore, since the nuclear particles themselves spin and therefore must have cyclical variations in their effective field strengths, then the electron rw must make an integral number of spins for each orbit in order to mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 66 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset stabilize in that orbit. thus orbital energies must be quantized with respect to spin or rotational energies er . matrix quantum mechanics requires that the energy level of an electron orbiting in an atom be h (n 1/2) where is the frequency and n is the number of typical photons which are absorbed or emitted. according to rotational kinematics, the energy level should be equivalent to the total angular energy of the electron rw, which is equal to its orbital energy plus its innate rotational energy er . the rotational energy er = h /2 explains why the ground state or “zero point” energy of the electron in an atom must be h (n 1/2) where n = 0 for an electron with no orbit. also, the concept of the rw simply explains why matter has a wave probability distribution. since the wavicle is purely a rotating electromagnetic wave, then the probability of detecting the wavicle near some point in space should be described by a wave function. the derivative operators, postulated by erwin schródinger, are simply deduced from the basic wave equation of the rw and the effects of relativistic quantum mechanics are graphically illustrated with the addition of potentials. the only real wave function of the rw is that which describes the amplitude at a certain time t and length s as measured along the wave’s helical path shown in figure 14. figure 14: cylindrical model of the helical path of real wave of amplitude and measurements of & in the direction of the particle motion and in the direction of the wave’s rotation. vector ally. given an arbitrary maximum amplitude n , wavelength , and spin angular velocity , the sinusoidal real wave function of the traveling rw must be defined as: 2 = n sin s t 11. comparison of dirac matrix equation with rotating wave vectors it was a busy time for new physics in the first three decades of the twentieth century. after the photoelectric effect, relativity, and bohr’s atom, came louis de broglie’s insight in 1924 to suggest that if light photons can be considered as particles as well as waves, then matter might also have a wave nature and its wave function must comply with relativity. later in 1924 wolfgang pauli suggested an inner degree of freedom of the electron, followed by ralph kroenig and then in 1925 george s. uhlenbeck and samuel e. goudsmit had theorized that mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 67 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the electron must have an inner rotational motion (later termed “spin” by pauli) in order to have an associated magnetic moment and thus explain spectroscopic evidence. hans c. ohanian in his review ( what is spin?) [1] states it apparently was immediately recognized by goudsmit and uhlenbeck that spin would very likely lead to serious problems with special relativity”. however, much concentration at the time was on the developing quantum mechanics and classical concepts were deemed insufficient to describe the macroscopic world. then in 1926 schrödinger really started quantum mechanics with his wave equation and had then tried to further it with relativity, but did not derive electron spin. also, pauli knew that the spin of a rotating body could be described by matrices and hence introduced matrices into the wave equation, which in turn suggested pairs of opposite spins of the electron. knowing that the light wave can have two possible directions of polarization, c.g. darwin suggested that the electron might also have two opposite polarizations which then yielded the correct fine structure of the hydrogen spectrum. it was paul a.m. dirac who in 1928 then used the matrices to combine the special theory of relativity with wave mechanics and naturally derived electron spin. however in his “quantum theory of the electron” [2], dirac further clearly credits gordon (and thus klein) for suggesting that the time derivative operator for the relativistic hamiltonian w = ih / t should be linear in the first order (and likewise the momentum operator pr = ih / xr ), just as in the case of the non-relativistic wave equation. quoted from p.a.m. dirac: what is the probability of any dynamical variable at any specified time having a value lying between any specified limits, when the system is represented by a given wave function n . the gordon-klein interpretation can answer such questions if they refer to the position of the electron (by use of nm ), but not if they refer to its momentum, or angular momentum or any other dynamical variable. we should expect the interpretation of the relativity theory to be just as general as that of the non-relativity theory. thus dirac got the idea to factorize the relativistic wave equation in order to get the first order derivative operators which then suggested a positive charge (positron later discovered) as well as the electron. again quoted from p.a.m. dirac: the true relativity equation should thus be such that its solutions split up into two non-combining sets, referring respectively to the charge e and the charge e. 11.1 derivation of dirac’s matrix/wave equations dirac first considers the case of no field present and and posits the form of the four dimensional wave equation (p0 1p1 2 p2 3 p3 ) = 0. this is the same as dirac [2] eqn 4. which we shall refer to as d4. then he multiplies the conjugate (with minus p 0 ) and the non-conjugate in his equation [2] d5, 0 = ( p0 1p1 2 p2 3 p3 )(p0 1p1 2 p2 3 p3 ) (37) to get the required equation (d3) with no field present: (vectors in bold): 0 = ( p0 2 p2 m2c2) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 68 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset with derivative operator: p0 =w/c = (ih/c) / t = relativistic hamiltonian. readers can refer to the quantum theory of the electron/pam dirac online. dirac derives the various matrices required to get his wave equation (d9): [p0 1( , p) 3mc] = 0 where denotes the vector ( 1, 2, 3). finally dirac considers the electron in an electromagnetic field and adds in the vector potential and scalar in his equation (d14): e e [p0 a0 1( , p a) 3mc] = 0 c c and then analogous to his equations (d3) and (d5) he multiplies the conjugate [with e (p 0 a 0) ] and the non-conjugate in his equation (d15): c e e 0 = p0 c a0 1 , p c a 3mc e e p0 a0 1 , p a 3mc c c e 2 = p0 a0 , c e 2 e 2 2 p a m c c e 1 , p c a p0 c a0 p0 c a0 , p c a the last equation above is d15. note rewritten, equations (d5) and d15) can take the form: p0 2 = [ 1( , p) 3mc]2 e e 2 2 e e p0 c a0 = 1( , p c a) 3mc the first eq. is d3 last eq. is d15a. upon squaring the terms in equation (d15a), dirac finds extra terms: e 2 e 2 e e 2 2 p0 a0 = p a ( , h) i 1( , e) m c c c c c (43) where this is d15a, again, here: = h/2 . from that, dirac divides by 2m and finds: e ( , h) e = = magneticmomentof 1bohr magnetonand mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 69 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset c 2m mc e ( , e) e i 1 = i 1 = electricmoment with imaginarynumber c 2m mc (44) quoted from p.a.m. dirac: this magnetic moment is just that assumed in the spinning electron model. the electron moment, being a pure imaginary, we should not expect to appear in the model. it is doubtful whether the electrical moment has any physical meaning, since the hamiltonian in (14) that we started from is real, and the imaginary part only appeared when we multiplied it up in an artificial way in order to make it resemble the hamiltonian of previous theories. 11.2 rotating wave vectors and derivative operators again refer to figure 14., where the sinusoidal wave function was defined as; 2 s = n sin t since for a light wave p = h/ then for a rotating wave pc = h/ and thus: pcs = n sin t . it is also apparent from figure 10. that: pc = pvc/vv = prc/vr and s = svc/vv = src/vr such that: ps p s c2 = n sin c t = n sin vvv2v t p s c2 = n sin rvr2r t and thus, = npc cos pcs t s sv = npv v c2 cos pvvsv2v c2 t 2 v srnpvrr c2 prvsr2r c2 t = 2 cos deriving further we get, 2 npc2 pcs pc2c4 2 = 2 sin t = 4 2 (4 (4 (4 (4 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 70 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset s c 2 v2 = np4v2c4 sin pvvsv2v c2 t = vpv4v 2c24 2 s vv s2 r = npvrr 2c4 sin prvsr2r c2 t = vpr4r 2c24 2 4 2 c4 2 thus: pc = 4 2 c v4 2 v pv = 4 2 c v4 2 r pr = 4 2 c and thus: pc 2 = (p v 2 p r 2) . with pc, p v, and pr as either simple variables or derivative operators. note, one can extend the rotating wave equation into the general theory of relativity: pc2 = (pv2 pr2 pt2) 11.3 comparison of derivative operators between dirac & rotating wave. in order to compare with dirac’s equations we of course need to limit our discussion here to the special theory of relativity. when the electron is in constant motion, the momentum operators of the rotating wave can also be related in the vector sum: pc = pv pr which upon multiplication by the amplitude of the wave function and then squaring yields the equations: pc = (pv pr ) pc 2 = (pv 2 pr 2) . note in above equations (d3) and d15a) the dirac terms which relate to the vectors of the rotating wave are: p0 = pc, p = pv and mc = m0c = pr for constant motion (where m0 is the rest mass of the rotating wave). thus when an electromagnetic field is introduced to the electron, the associated vector potentials can be added respectively (see figure 15): e e e pc ac = pv av pr ar c c c which represents another (boosted) state of constant motion. see figure 15. the newly introduced potential e/c ar has a magnitude and direction such that the spin momentum is always conserved in magnitude and changed mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 71 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset only in direction in order to maintain itself at right angles to the direction of motion of the particle. vectors noted are embolded. figure 15: the vector potential is added to the 3–space vector momentum while the spin momentum is maintained at right angles to the direction of motion. the dashed lines indicate the resultant momenta with added potentials.. if we are going to conserve the rest mass energy and momentum in the rotational direction (as in the special theory of relativity), while applying potentials from an electromagnetic field that change the direction of the electron’s angular and magnetic moment, then the magnitude of mvr will remain = m0c = pr, but note pr must change in direction in order to remain at right angles to the translational motion and momentum of pv = mvv . p02 = 1( , p) 3mc 2 2 2 e e p0 c a0 = 1( , p c a) 3mc in comparison, as noted in previous sections, the rotating wave momenta can be added vectorially: pc = pv pr for special theory of relativity (constant motion), pc = pv pr pt for general relativity and likewise when squared: pc2 = pv2 pr2 = mc2 = (mvv )2 (mvr)2 pc2 = pv2 pr2 pt2 = mc2 = (mvv)2 (mvr)2 (mvt )2 also note in the above it is implicit that: pv = p1 p2 p3 = px py pz . these are mutually orthogonal 3 dimensional momentum vectors and when squared’ pv2 = p12 p22 p32 (57) also note 0 = pc2 pv2 pr2 ipr = ( ipc pv )(ipc pv ) if the vector potential and scalar are added in the same way as dirac: e e e pc a0 = pv av pr ar c c c where here av = the real 3 dimensional vector potential = ax ay az , and then after squaring we get: 2 2 2 e e e pc ac = pv av pr ar (60) c c c (5 (5 (5 (5 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 72 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset however, dirac gets: 2 2 e e 2 pc ac = pv av pr extra terms noted in (d15) above. c c (61) since we are conserving magnitude of momentum and energy in the rotation, then 2 e 2 pr ar = pr and thus: c e ar = 2pr = 2m0c = 2 c r0 recall from the previous section 5. a definition of rest (energy) mass that h = 2 r0m0c and thus = r0m0c . thus the rotating wave has an angular moment l = which agrees with an orbital state of n =1 where n = [ ( 1)]1/2 and = 0 . the magnetic dipole moment is thus: e e e 1 = l = = r0m0c = er0c 2m0 2m0 2m0 2 note, a light wave has an energy defined by the poynting vector: s= e b/ 0. s is in the direction of motion of the light wave, thus the poynting vector for the rotating wave will be in the spiral or helical direction: s= ecs . since in the light wave e =cb , then for the rotating wave: eb e2 s = = and 0 c 0 ds e de e kqvt = 2 = 4 3 dt 0c dt 0c d 12. an explanation of the kaluza 5th dimension by the rotating wave. my initial references on kaluza’s idea are from the internet article of william straub phd: kaluzaklein for kids june 27 2014 [3] and i appreciate his sharing of knowledge as i do by many others. i also reviewed the kaluza klein site by victor toth as he always tries to make physics as simple as possible and intuitive, yet comprehensive. [4] i looked at many other sites but got the kaluza idea clear from those two. in 1919 the german mathematician theodor kaluza developed a theory in 5 dimensional reimannian geometry from which electromagnetism appeared to be a natural consequence of the 5th dimension. finnish physicist gunnar nordstrom had proposed a similar idea earlier in 1914 but it was ignored. kaluza immediately approached (6 (6 (6 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 73 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset einstein who became very interested and it was finally published in 1921 under einstein’s recommendation. for almost a hundred years physicists and mathematicians have studied and tried to make clear sense of the kaluza “miracle”. the basic idea is that the extra components of the 5 dimensional metric seem to materialize in 4 dimensions as components of the electromagnetic vector potential. after rechecking the derivation of the g k in previous section 12 and becoming sure of the intuitive model of the rotating wave, i began to realize that its 5th vector vt was most likely the same 5th dimension as suggested by kaluza. without the radial (outward or inward) vt vector part of the rotating wave, one cannot derive intrinsic curvature of the surface on which the light line travels. in other words, the general theory of relativity gtr could not be explained by the rotating wave function, unless it is allowed to spiral outwards (slowing down) or inwards (speeding up). the vector vt essentially turns the light line inwards or outwards and thus deforms the metric. also, the fact that electromagnetic energy adds curvature in addition to mass energy very clearly suggested to me that the kaluza 5th dimension must be the same as vt , the 5th vector of the rotating wave. most recently, i came across the article geometrical interpretation of electromagnetism in 5-dimensional manifold by taehun kim & hyunbyuk kim [5]. in the article, they suggest the 5th dimensional manifold is constructed by dragging the 4d space-time, resulting in deformation. clearly, as shown in figure 13, one can see that the rotating wave vt vector likewise redirects the 4d space-time manifold inwards (or outwards). in analyzing the kaluza klein theory, physicists usually start with the equation of motion. as straub states, the lorentz force in the usual 4 dimensional space can be derived from an arbitrary coordinate variation x of the invariant quantity: i = mc ds q a dx and carrying the variation and setting it to zero yields the expression for the lorentz force: d2x dx dx q dx 2 = f ds ds ds mc ds now let ds/dt = c (speed of light) as defined in the rotating wave figure 13 where c2 = g u u thus: 1 d2x dx dx q dx 2 2 = 2 f c dt dt dt mc dt and thus: q a , u u = f u m now a vector can be constructed by pairing the contravariant components with covariant base vector components so: e (a u u )e = ( f u )e m q e a u u = f u mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 74 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset m where f is now embolded because it acts like a base vector. note that as indicated previously eq. (16) for the rotating wave model: c = ecc = vv vr vt = e u vt also, as is common practice when analyzing kaluza klein theory, greek indices are again here used to denote 4 dimension quantities (c4 = e u ) while latin indices are used to denote overall 5 dimensional quantities (c5 = e u = e u vt ). to be clear: c5 = c4 v t thus for 4 dimensions when vt = 0 (rotating wave cylinder condition of constant translational motion): dc4 dec 2 de = c = c r4 = e du u dt dt dt q = e a u u = f u m and for the rotating wave 5 dimensions (or 5 vectors): dc5 2 de dvt = c r5 = e du u dt dt dt dvt = e a u u dt now, as per the standard model of general relativity the equation of motion (eom) is set to zero for the straightest geodesic and thus the rotation curvature r5 is not considered nor observed. so for the moment let: 2 dvt c r5 = 0 = e a u u dt dvt e a u u = dt but from the variational principle eq.(67) leads to eq.(72) 2 q dvt c r4 = e a u u = f u = m dt thus according to the rotating wave model, the extra term (et ) generated by the kaluza klein 5 dimensional model is clearly: dvt q et = = f u dt m also note as per the rotating wave model, 2 2 dvt c r5 = c r4 dt mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 75 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset so according to the rotating wave, the f u would appear to rotate like the r5 and r4 . expanding further, e et = f u m e v 2 2 e c r5 c r4 = f u m dvt d bet t dvt = = v et dt dt dt = f u = r vt et at m pt so when a homogeneous electric field is present, there appears to be a boost in potential that is both rotational (v r p t 1v t ) and radial ( e t at ). one can imagine this intuitively when using the right hand rule of thumb: it is like tightening the fist while pushing the thumb forward. when the homogeneous electric field is attracting the negative field of the electron?s rotating wave, then the potential is positive and the rotation and forward translational motion is immediately amplified. in that case, the light line (radius at which rotating wave speed is c) spirals inwards (tightens) creating the bullet form of intrinsic curvature and the mass energy is increased. when the potential is negative, the rotation and translational motion are immediately decreased. in that negative case, the light line spirals outwards and mass energy is dissipated. in comparison to the gravitational theory and its slowing down of time and energy, this suggests some additional impact on the expansion of the universe by electromagnetic interactions. consider a rotating wave held stationary (on the wall) while in a homogeneous attracting electric field. at a certain radius rr , the tangential velocity of the rotating wave is traveling at the speed of light cr = vr and thus; dcr 2 q r = c rr = f ru dt m and the rr is simply the inverse of the radial vector. now consider a rotating wave (off the wall) and free falling straight in a homogeneous attracting electric field: c4 = vv vr = vvcr c5 = vv vr vt dc4 2 q = c r4 = f u dt m dv q r = ev f r u dt m c2r4 = av (q/m)fr u r dc5/dt = c2r5 = (q/m) f u dvt /dt = av (q/m) f r u r dvt /dt c2r5 = av (q/m) f r u r d e t/dtvt e tdvt /dt = av (q/m) f r ur vrpt 1vt at letting c2r 5 = 0, then the extra term, (7 (7 (7 (7 (7 (8 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 76 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset et = vrpt 1vt at = av (q/m) f r ur and thus: dvv/dt = (q/m) f vu v dvr/dt = (q/m) f rur dvt /dt = (q/m) f tut . taehun kim and hyunbyuk kim also suggest “is possible to imagine a mechanical wave propogating along a particle-thread”. that thread according to the rotating wave model would appear to be the light line at a radius where the wave front has the constant speed of light (c ). again that light line would be dragged or deformed by an electric field outwards or inwards depending on charge. essentially the enormous difference between the strength of electromagnetism and gravity can probably be accounted for by comparison of the direct and immediate deformation of electric field verses the slight and indirect affect of a rotating wave on another wave via the bending interaction through the permeability and permittivity of em vacuum field. the rotating wave theory is grounded in the 3 dimensional space we are very familiar with and observe everywhere. the rotating wave theory suggests that the 5th dimension as suggested by kaluza is likely the 5th radial vector vt of the rotating wave. the rotating wave obviously requires faster than light velocities at greater radii plus nonlocal interaction. what one observer sees might be just another perspective compared to others. in an article prepared by lance l. williams [6] he states that:“it has been little – appreciated but motion in the 5th dimension is identified with electric charge. he also notes: the 5 d theory would seem to offer an avenue toward breakthrough physics (breakthrough propulsion) because it satisfies the expectations for such a theory as well as hinting at a possible approach to hyper–luminal travel: the 5th dimension.” note that as per the rotating wave, the speed of light increases at greater radii. perhaps it is possible to detect rotating waves like beacons of light at great distances, albeit with associated weak fields. with futuristic applied technological advances, that might permit communication across stellar distances and significantly further the potential of quantum entanglement. in the more near term, perhaps we could just try to model the rotating wave and see what technological applications it might have. the rotating wave suggested to me long ago that we might be able to create an electromagnetic propeller that can “push or pull” against the em vacuum field of space. the “push or pull” traction is due to transmission and rotational energy could be redirected into forward motion. certainly, if we are going into space for the long haul, we can’t afford to pollute it with micro particles from propellant along the same trajectory. also, a massless rocket (like an electromagnetic propeller) would certainly be much more efficient overall with much less fuel payload. furthermore, the acceleration and deceleration along trajectories would save time and have fewer moving parts, making space travel more comfortable and safe. newton wondered why gravity worked. einstein explained that mass bent space. but again, then why does mass bend space? i think it is the rotating wave affecting the permeability and permittivity of the em vacuum field. what binds the photon into rotation in the first place is imparted to other interacting waves. 13. zitterbewegung (zbw) as evidence of the rotating wave many people are familiar with david hestene’s work on zitterbewegung as well as geometrical algebra and his space time algebra (sta). i came across his article of 1990 [7] and immediately noticed a similarity between zitter and the rotating wave. right at the outset of the abstract, hestenes states: the zitterbewegung is a local circulatory motion of the electron presumed to be the basis of the electron spin and magnetic moment. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 77 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset hestenes notes that the rest frame s (= m0c 2 where here m0 = rest mass) energy has a familiar form of rotational kinetic energy for a body with angular momentum s and rotational velocity . the s= mc2 suggested to hestenes that the “rest mass” of the electron has a kinetic origin. refer to previous section 5. a definition of rest (energy) mass. according to the rotating wave, the rest (energy) mass e0 = rotational kinematic energy (e r =1/2m 0c 2) e b (binding energy) = m0c 2 and thus er = eb . the mass is due to kinematics of a rotating wave brought into classical rotation by a binding energy.hestenes states that “in analyzing free-particle wave packet solutions of the dirac wave equation, schrödinger noted the existence of “interference” between positive and negative energy states oscillating with circular frequency 0= 2m0c 2/ =1.6x1021s 1 . that would be like a wave rotating at a billion billion times a second. no wonder it interacts like a hard particle as well as a wave. hestenes further states:“but the greatest challenge will be to prove that the zbw is a real physical phenomena and not just a metaphorical trick.”he had already thought that “barrier penetration can be interpreted as manifestations of the zbw”. apparently, louis de broglie in his 1924 doctoral thesis had already proposed that the electron has an internal clock, with frequency at about a billion billion times a second. while schrödinger adopted de broglie’s wave hypothesis in his famous equation, de broglie’s clock hypothesis was ironically forgotten. in a later article hestenes reveals that he met with french experimental physicist michel gouanere “who argued that if the electron clock is physically real, channeled electrons should interact resonantly with the crystal periodicity at some energy to produce a dip in transmission rate.” gouanere and colleague m. spighel had already conducted an electron channelling experiment which supported the electron clock and was published in annales de la fondation louis de broglie in 2005, but was rejected by physical review letters and many said it was implausible. i suspect that implausibility was the billion billion times a second. one reviewer said perhaps it could be explained by zitterbewegung, so gouanere got in touch with david hestenes.as noted in previous section 11. hans c. ohanian [1] noted that goudsmit and uhlenbeck in 1925 immediately realized that their proposed electron “spin” would very likely lead to serious problems with special relativity, but quantum mechanics was just starting to develop and was drawing more attention at the time. the dirac matrices appeared to refer to some characteristics of the electron itself and thus dirac commented on their presence in the energy equation of an electron:“they must therefore denote some quite new dynamical variables, which may be pictured as describing some internal motion in the electron. we shall see later that they just describe the spin of the electron.” – paul a.m. dirac the key to the rotating wave and relativity is that: when a light wave travels in a straight direction it moves at the speed of light, but when it rotates, it travels at greater velocity at further radii from it center of spin. in 2008 michel gouanere along with denis dauvergne, robert kirsch, jeanclaude poizat, joseph remillieux, michel chevallier, cedric ray, etienne testa, robert chehab, marcel bajard, and philippe lautesse proposed ricce (research for an internal clock by channelling of electrons), [8] . i don’t know the details nor the outcome of ricce, but i suspect that if one posits relativistic properties purely as a function if the rotating wave and not a connection between space and time itself, alternate findings might be considered and observed. 14. stern gerlach and 720 degrees stern gerlach: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 78 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in 1922 otto stern and walter gerlach performed an experiment which involved sending a beam of silver atoms through an inhomogeneous (non-uniform) magnetic field and onto a detection screen. the silver atoms were each considered neutral in charge, but had an extra electron. classical spinning particles would be expected to just show up on the detection screen in a random pattern, but the beam split into exactly two which indicated that half of the electrons had an intrinsic quantized angular moment of /2 (spin up) and the other half had /2 (spin down).the stern gerlach quantum mystery still is: why does one particle appear to have a possible spin of either up or down and not just in one way? electrons have a spin opposite to that of positrons, but they are two types of particles which cancel each other out in annihilation. electrons do not cancel each other out, but appear to have two types of spin. note that the rotating wave model of the electron has a forward (translational) motion in line with its axis of spin. thus if an electron orbits clockwise around a silver atom nucleus, it will have a specific direction and angular moment of spin. furthermore, the most stable motion of a whole silver atom would require that the orbital plane of the extra electron be in line with the trajectory of the atom towards the detection screen. however, for each silver atom with a clockwise (or upside up) orbit there is an equally statistical chance of having a counterclockwise (or upside down) orbit. one is just the mirror of the other. hence, the orbit-up motion of the silver atom could be observed and interpreted as spin-up while the orbit-down motion could be observed and interpreted as spin-down. that might invite discussion and argument, but it is one possible way that i can think of in explaining quantized spatial orientation of spin with the classically rotating wave. 720 degrees and spin ½ apparently a rotation of 360 degrees does not return the electron to its original state. it requires a 720 degree rotation to do that. also note that this is true not just for electrons but any spin-1/2 particle. now note that as per figure 4, there are two symmetrical nodes so when the rotating wave is spun 1/2, it looks the same as the original. the intrinsic spin angular moment is one half of the orbital moment, so for each orbit the electron spins only half the way around. it would take two orbits or 720 degrees of rotation to get the electron a full spin and back to the original state. i also note that there are two nodes on the ½ spin electron rw. perhaps there are three nodes on others particles, such as quarks with -1/3 and 2/3 charge. 15. possible solutions to paradoxes of modern physics the foregoing concept of the electron wavicle might resolve well known paradoxes of physics such as the waveparticle duality of both light and matter, the epr (einstein, podolsky and rosen) paradox, and the age-old zeno’s paradox of motion. by this concept one would expect the electron to be affected by a double diffraction slit in just the same way that a photon would, simply because the electron is composed of half a spinning photon plus binding energy. similarly, the photo-electric effect might be explained by the consequent oneon-one relationship of the photon and the electron rw. in 1935 einstein, podolsky and rosen published a paper on a thought experiment which stated that if the position and momentum of only one of two particles is measured after an initial measure of their combined position and momentum, then the final momentum of the two particles cannot be the same unless there is some kind of instantaneous “action at a distance” or “non-local reality” between the two particles. however, modern experiments, which have measured the polarization of twin photons instead of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 79 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset position and momentum of particles, have confirmed the violation of bell’s inequality and thus support the “nonlocal reality” of neils bohr’s quantum theory and the epr paradox. the apparent action at a distance might be simply due to the action of the infinitely extended rotating wave of the rw. the apparatus which interferes with one photon while measuring its polarization would, according to the rw, also interfere with its twin photon of equal and opposite momentum. the twin photon, although at a greater distance from the centre of the interfering apparatus, would still be affected by the same electromagnetic wave function of that measuring apparatus. the locality of a particle might be thus better interpreted as the centrality of spin of the rw’s electromagnetic wave. zeno’s paradox prescribes discrete motion of particles. however, the electron rw is transmitted through the em vacuum field as a wave. the em vacuum field might also be predicated upon a substrata energy fieldof wave functions and perhaps enable the creation and transmission of electromagnetic waves and move themselves very likely with speeds much greater than that of light. given an infinite amount of real time and space, an infinite number of energy strata could have evolved into something as substantial as light and thus the existence and motion of matter. 16. conclusion the rotating wave (rw) model of the electron provides an elegant and simple solution for wave function of matter and in doing so, it explains the apparent relativistic connection between space and time. a number of physicists have considered the “circular motion” within the electron, but tried to maintain the direct connection between space and time. an in depth study of louis de broglie’s thesis would be interesting because he studied relativity, was the first to consider matter as a wave form, and apparently also considered there might be circular form of motion in the electron. basically, the rw agrees with the assumption that the speed of light is independent of it’s source and is constant at speed = c in a straight direction. however, the rw also requires that the bending of light allows for speeds greater than c at greater radii. given that, everything seems to naturally derive from a classical rotation of “spin”: mass, charge, magnetic dipole, relativity, quantum mechanics, and a number of paradoxes. relativity and quantum mechanics are thus inseparably innate to the real wave equation of the rw. furthermore, rotation of the wave clearly explains how a magnetic dipole field is self-induced and thus how a magnetic field is induced by the motion of a charged particle.the rw form also allows one to derive the g k intrinsic curvature in detail and is congruent with the mass energy density tensor. that is perhaps not surprising because after all, the mass energy density tensor is itself indirectly derived from rotating wave forms of mass. one thing the detailed g k of the rw does in addition is to inherently explain the expansion of the universe. without expansion there is no curvature. any energy expended by the rw in its coupling with other particles or waves would, by its definition of mass, require its gravitational field to decrease as the rw’s time cycle of spin slows down. the rw’s inherent connection between gravity, spin and time thus provides an elegant explanation to the expansion of the universe.the rw model does yield additional insights which might stimulate unification theory as well as provide alternate models for teaching current theory. for example, by applying the definition of rest (energy) mass according to the rw, a radius rq, at which a hypothetical wave of the quark is rotating at the speed of light, can be defined as: rq = (m e r e)/ m q where m e and m q are the stationary masses of the electron and quark respectively. re is, of course, the radius of the electron wavicle at which its rotating wave is traveling at the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 80 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset speed of light. the radial distance rq could be compared with the distance to which the strong force extends. such speculations might provide some enlightenment upon current qcd theory. s.a. emelyanov in his 2012 [9] : “toward a real synthesis of quantum and relativity theories: experimental evidence for absolute simultaneity”, states that their observations leads them to believe that the de broglie-bohm and aether related lorentz-poincare theories are capable of providing a real synthesis of quantum and relativity theories. again, the rw model has two nodes of maximum amplitude (see figure 4) which create quantum mechanics and the planar wave fronts of these nodes incline and with a longer helical wavelength, thus creating relativistic effects (see figures 5, 6, and 8). dr. louis m. houston at the university of louisiana at lafayette posted his 2013 article in ijesit: “the physics of a rotating de broglie wave packet” [10]. as per his abstract, dr. houston finds that the field generated by a rotating de broglie wave packet results in a “quantized electromagnetic-centripetal field for a small angular range”.dr. robert close in portland has developed a classical wave description of electrons [11] that is likely similar to the rw model and which he uses for comparative modeling in teaching physics. [00] one thing i agree with on the classical wave description is that the wave function actually causes relativistic effects rather than just complying with relativity. in the emelyanov, houston, and close concepts, it could be very revealing in comparing the rotating wave vectors with the dirac matrix equations and rotating de broglie wave packet. after some analysis, that would be greatly facilitated by in person discussion groups, also including hestenes and kim. a revisit of the gouanere et el channeling and ricce type experiments [8] might be done in order to find out if the classical rotating wave model is correct.refer to figure 16 below. while comparing the spin and charge of an electron with its anti-particle the positron, i noticed that the quarks were of a different size as well as charge. the electron positron pair annilihate each other while the proton is formed of two up quarks plus one down quark. it is speculation only, but perhaps the next higher complex form of spin is the figure eight. the electromagnetic wave would be able to wind in a figure eight fashion because there are two maximum nodes with half spin for both the quarks and the electron (as shown in figure 4). figure 16: the rotating em waves are shown winding through the proton and the neutron in figure eight fashion, possibly manifesting the strong force. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 81 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset regardless of whether the rotating wave model is absolutely correct or not, more study might be done in that direction to advance theory and also see what technological applications might be developed. finally, the rotating wave theory might not have be so radical if the de broglie wave nature of matter had been established prior to the famous michelson-morley experiment. the rw model requires that all matter is being transmitted through space, after all it is energy. that would have avoided any discussion about aether drag. aether really is just the homogeneous electromagnetic field of empty space. it allows the transmission of light, matter, and other forms of radiation. it appears to extend through the universe as we know it, but perhaps there are more substrata fields which are so far undetected and extend much further. acknowledgements i wish to thank ernest von rosen m.sc. physics for his support and earlier attempt at publication. also, thanks goes to steve belleguelle for his program amiweb. i first heard the term "wavicle" mentioned by dr. carl sagan. i admire h.a. lorentz for all of his work as i do others, particularly albert e. einstein, all of whom i could not envisage the rotating wave without their diligent math and logic. to all of my teachers who inspired me to "always learn to be aware of what we are dealing with" thank you. w.h.f.christie. word document transcribed to latex by h. fearn and later transcribed to word for final publication. general references belinfante, f., on the current and the density of the electric charge, the energy, the linear momentum, and the angular momentum of arbitray fields, physica 6, 887 and 7, 449-474, 1939. crossley, dennis, conceptual barriers to a unified theory of physics, dept of physics, university of wisconsinsheboygan, sheboygan, wi 53081 august 31, 2012 overduin, j.m.,wesson, p.s., kaluza-klein gravity, arxiv:gr-qc/9805018v1, 1998 http://arxiv.org/abs/grqc/9805018 de broglie, l.v., recherches sur la theorie des quanta, ph.d. thesis, university of sorbonne, paris (1924) schrödinger, e, (1930), uber die kraftfreie bewegung in der relativistischen quantenmechanik, sitzungb. preuss. akad. wiss. phys.-math. kl. 24: 418. stenson, jared r., representations for understanding the stern-gerlach effect, thesis, brigham young university, august 2005 van huele, jean-francois, stern, barut, and gerlach today, department of physics and astronomy, brigham young university, n151 esc byu provo, utah 84602-4681 e-mail: vanhuele@byu.edu (received 28 feb 2005) references ohanian, hans c., what is spin?, rensselaer polytechnic institute, troy ny, published may 1,1986 american journal of physics (54) 6 dirac, paul.a.m. dirac, the quantum theory of the electron, published 1 february 1928.doi: 10.1098/rspa.1928.0023 http://rspa.royalsocietypublishing.org/content/117/778/610 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.6, issue 1; january febuary 2021; 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/tajes/index; mail: topacademicjournals@gmail.com 82 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset straub, william o., kaluza-klein for kids, pasadena, california, 91104, june 27, 2014 http://www.weylmann.com/kaluza.pdf toth, viktor t., kaluza-klein theory, http://www.vttoth.com/cms/physicsnotes/118-kaluza, december 01, 2004 http://www.vttoth.com/cms/physics-notes/118-kaluza-klein-theory kim, taehun and hyunbyuk kim, electromagnetism in 5-dimensional manifold, july 12 2015 arxiv:1507.03184v1 (gr-qc). http://arxiv.org/abs/1507.03184 williams, lance l., the nature of the 5th dimension in classical relativity, konfluence research,man itou springs, colorado 719-685-1163;http://www.konfluence.org/ final_aipv 1103p 243_1.pdf hestenes, d. the zitterbewegung interpretation of quantum mechanics, found. phys. 20 (10), 12131232 (1990) http://modelingnts.la.asu.edu/html/impl_qm.html gouaniere, michel et al, (2008), a search for the de broglie particle internal clock by means of electron channeling, foundations of physics 38: 659-664. https://www.lnf.infn.it/acceleratori/public/btf_user/ricce/ricce.pdf emelyanov, s. a., toward a real synthesis of quantum and relativity theories: experimental evidence for absolute simultaneity, division of solid state electronics, ioffe institute, 194021 st. petersburg, russia dice2012 iop publishing, journal of physics: conference series 442 (2013) 012035 doi:10.1088/17426596/442/1/012035 houston, louis m., the physics of a rotating de broglie wave packet, the louisiana accelerator center, the university of louisiana at lafayette, ijesit vol 2, issue 6, november 2013 http://www.ijesit.com/volume%202/issue%206/ijesit201306_78.pdf close, r. a., classical wave description of electrons, 2015 07 29 http://www.classicalmatter.org/classical electron.html 2015-07-29 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset "education reform in the spotlight: a closer look at the 2016 presidential campaigns" john m. anderson dallas home-school texas education agency usa abstract: the phrase "last hired, first fired" has haunted the job market, particularly during economic downturns, such as the great depression of the 1930s and the more recent great recession (2007-2014). this phenomenon disproportionately affects african-americans, especially unemployed black males. this study delves into the profound impact of standardized testing on the employment prospects of african-american individuals, shedding light on the systemic challenges they face. by examining historical trends and data, we aim to uncover the factors that perpetuate this unsettling pattern. keywords: standardized testing, unemployment, african-americans, racial disparities, economic downturns introduction why education should be a topic of concern in 2016 us presidential campaign? ever heard of these four chilling words? “last hired, first fired”. i am talking of the immediate by-products or victims of standardized testing: “students” who; if lucky to get a job, and before long – get fired. these bitter four words dominate the labor market especially during economic downturns, example; in both the great depression of the 1930s and the more recent great recession (2007-2014). what is heart wrecking is that this double-down cliché; is so deep rooted that unfortunately; it is held particularly true for africanamericans; especially unemployed black males. as an entrepreneur, educator, researcher, protagonist, volunteer, author, advocate, parent, and reflective thinker; i look back 13 years ago and reflect on the first encounter of the latest news in august 2001, regarding the new federal law “no child left behind act (2001)”. i remember vividly the faculty orientation meeting, when the news first hit my ears; i was focusing on the welcoming speech being presented for new faculty at one of the us universities in alaska. i was not paying attention to the nuances of the speech content, as i was recovering from the nuances of the jet leg from michigan to alaska, and summer doldrums of the tundra, when i thought i heard that… “…in year 2014, every student in the usa would be proficient in reading and mathematics” (no child left behind act, 2001). “could i have heard the news well?” i quizzed myself. i definitely was completely swept off balance and nonetheless shaken out of my outlandish reverie. however, i cautiously gathered up courage to raise my hand to question the speaker if what i had simply day-dreamed, or worse still, misunderstood the queen’s language. to my surprise and disbelief, i was assured that what i had heard was perfectly correct. that invited my lower jaw to drop! the only thing to do would be to move on and deal with the current education, teaching and learning issues one day at a time. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset days and months reeled by as it became reality that “no child left behind act (2001) was here in the usa education system to stay. sooner or later, various faculty members, students and i included, started to realize that the elephant had gotten a vip seat in the living room, right in front of our noses, and indeed it was time to smell the coffee for others as well as smell the rat for the rest! something bizarre was going on. strange it would look, it became huge and obvious. the buzz caption amongst educators, non-educators and learners would be: “but alas! wait a minute. what? … in year 2014, every student in the usa would be proficient in reading and mathematics” (no child left behind act, 2001), “that’s setting up for failure!” why? educators feared the notion of measures that would tie teacher pay to student test scores and performance. that would be termed: accountability based on “highstakes” standardization. most educators and student teachers alike, pondered that anyone in their right mind would frankly know that not every student could be proficient at one given time. it was common knowledge that at the time; 2014 seemed a long way off. however, to claim that every student would be proficient in math and reading by that deadline; sounded like an ill-gotten façade. the federal law would not only target students, but also noncertified teachers regardless of years invested in the teaching service would have to undergo re-training and become state certified by a certain specified given time period or face losing jobs in the name of “bad teachers” or politely “accountability”. that was a big knock-out for especially paraprofessionals who might have invested up to more than ten years in non-certified teaching, and would be “forced” to hurriedly go back to school as non-traditional students in the wake of “no child left behind act, 2001”. as a reflective educator, i would reiterate that at the time, in terms of accountability of teacher evaluation and student assessment as proposed by the no child left behind act, the outcry was: “that’s set up for failure and bad fortune for the educator who would likely be laid off under the label: [bad teacher]”. it would also be bad fortune for the low achieving students who would likely face the embarrassment of repeating a grade plus having their schools labeled as failing bad-schools; and most likely to be condemned for closure. education, students, teachers & “pygmalion phenomenon” rosenthal and jacobson (2013) argue; “the pygmalion phenomenon is the self-fulfilling prophecy embedded in teachers' expectations. simply put, when teachers expect students to do well and show intellectual growth, they do; when teachers do not have such expectation performance and growth are not as encouraged and may in fact be discouraged in a number of ways”. these insights remind us that education definitely needs a voice in politics. focusing beyond 2015, we agree that 2014 is yesterday’s news, and today, most teachers in the usa are in disillusionment, especially when statistics show that on the global stage, us schoolgoing students rank 15th place in reading and mathematics. teachers bear the brunt of drilling children to “pass” the math and reading tests at the expense of other subjects. the deep rooted pain felt by most teachers is powerlessness to become innovative, constant fear of losing their jobs, and getting punished if students they taught failed the “high-stakes” standardized tests administered by outsiders who did not design, develop, or implement that curriculum. teachers’ frustrations poised by the no child left behind act of 2001, could be characterized by classroom boycotts and teachers’ protests; example carried out in chicago in september 2012, a scene that left many families stranded without clues on what to do with their school-going children. as 2016 us presidential elections are around the corner, yesterday’s events relating to educational boycotts, standardized mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset tests and cheating scandals by school officials in order to attain high educational scores for students in places like atlanta georgia, and others; remind us of the problems that are bred by “high-stakes” standardized testing; an educational phenomenon that should never be forgotten by every political strategist. as 2015 ends, the future reality in terms of education detects that times are hard, budgets have shrunk, and teacher lay-offs have mushroomed. however, something strange is unfolding at state level. so far, thirty states in the usa have requested for no child left behind act “waivers” from the adventurous goal that is far from getting unattainable in today’s educational arena. what my education colleagues and students once cited as a standardized testing outcry in the article entitled: “present day students a.k.a. victims of standardized testing” (2005) would still be a burning issue as of today? evidence shows that the us department of education in 2012 openly stated that: “….this accountability system is flawed and sets up students, schools, and states to fail”. that phenomenon boosted my pursuit of this qualitative research study. materials and methods materials: extremely cheap materials: person, paper, pen, paper and respondents this article includes mixed investigative qualitative research (2001 – 2015) carried out using holistic approaches that sought dynamic reality changes brought about by value-bound conditions of “high-stakes standardized testing” within education community. qualitative research generically entails ethnographic, naturalistic, anthropological, field, or participant observer methodologies. emphasis is on interaction, listening; looking, and focusing on diverse variables in their natural setting. comprehensive and detailed data is gathered through open ended questions that provide direct quotations. integral to the investigation; is the researcher (jacob, 1988). qualitative research differs from quantitative research which attempts to gather data by objective methods to provide information about relations, comparisons, and predictions and attempts to remove the investigator from the investigation (smith, 1983). qualitative research seeks to understand people’s viewpoints, perceptions, and interpretations. the orientation of qualitative research is anchored on exploration and discovery, which propagates theories and hypotheses as they evolve from data as collected. further, subjective is the data. it culminates the perceptions of the people in the environment. instrumentation for the primary data collection for this particular research design is the human person, in which case i was the primary data collector. the validity of results in qualitative research focuses on design and procedures tailored to gain "real," "rich," and "deep" data. methods alaska when i went to alaska, this was at the height of the introduction of the “no child left behind act” nclba (2001). for my qualitative research, i used triangulation, a process involved in corroboration and convergence of multiple data. (alaska, kuskokwim). the nclba news came with deadlines which required that some school teachers who had invested in years of non-credentialed teaching; would in very little time; go back to school for in-service training, take extra teaching courses by a certain deadline, and pass the examinations that would come with the courses. if not, that would mean losing their jobs, regardless of having been in the field for twenty years or so. the in-service would take place while those teachers were also employed fullmailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset time, a process that included lesson planning, class management, grading students’ papers, attending teacherparent conferences, and so on. as a researcher, this is one of the situations were a holistic description of events, procedures, and philosophies occurred in natural settings that responded to expectations of “high– stakes” standardized testing. louisiana relentlessly, i continued my quest in nclba qualitative research later on in louisiana this time. as a passive participant whilst exploring the impact of high-stakes standardized testing in and around lake charles, louisiana; iassumed a spectator / bystander role at the scene of action without fully participating. what i found depressing in one of the schools in lake charles as a passive participant, was the pain that was seen among teachers and students who were at this particular predominantly black; “x” elementary school which had been labelled as a “failing school”. i remember fully, the agony displayed on students’ faces as they trickled through the school hallways and school grounds that barely had a playground, knowing full well that their school had been labelled as “poor performing” and they were called “bad students”, taught by so-called “bad teachers”. the untold grief from the “stigma” was deep, if not heart wrenching and contagious. i further felt the agony of removing my child from that school, after a number of friends and colleagues (educators by the way); had hinted to me that sending my child to that particular x “failing school”, was simply a: “no! no!” i asked: “why?” the answer was: “that is a failing school. many of those students there will end up in jail. that school is an incubator for future prison / jail inmates.” those chilling words convinced me to follow the advice given. i remember vividly, the lame excuse i had to use to that “x” school principal / head; when asked why i was pulling out my daughter who had simply attended the classes there for only five days. it should be known that the stigma carried by a school that is labeled as “failing school” has unprecedented ripple effects of harsh isolation, horrendous stigma, and punishing humiliating all due to results of “high-stakes” standardization. from an educator’s point of view, it denotes a “broken system” and one starts wondering what the root cause could be, especially when elementary school “x” was predominantly black, with students from low income neighborhoods. my action research would endure breadth by learning how other parts of the specter succumbed to the changes in the education system due to “high-stakes” standardized testing. that dichotomous venture landed me in georgia. georgia when it came to milledgeville, georgia; i decided as an nclba qualitative researcher to become an active participant, starting with observation(s) in order to learn rules, followed by becoming actively engaged in activities from different settings. at this particular liberal arts university in georgia, i had the opportunity to get involved in team teaching. i was able to combine forces with a colleague and students in a project called the “outsider within”. this project entailed total participation and as action researchers, we were the natural participants operating at the highest level of involvement. the ethnographic study allowed the students to walk in other’s shoes, thus visiting with different classrooms in under-privileged communities, observe, make anecdotal notes, and document findings. our undergraduate students in this project were all from middle to high income neighborhoods near and far from atlanta, and had barely experienced what it was like to be in a poor school without a cute playground, or inadequate school supplies and books. from the group of up to mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 100 plus or minus students, 99.9% were extremely surprised that teachers from struggling neighborhoods had to bring their own school supplies from home to allow the students to use in their classes, and 100% of these students agreed that educational poor environments were not conducive to effective learning and teaching. 100% of these students expressed fear of teaching lowincome black students upon attaining their teaching certificates. it is from this tireless, adventurous, fact-finding, evidence-based project that one of the undergraduate students coauthored with me a published article entitled: “students a.k.a. victims of standardized testing” (aaron a. &tsiwo-chigubu 2005). to enrich the diversity and gravity of the evidencebased qualitative research on this topic, it became necessary to include delaware’s historically black university, in-order to compare and contrast the experiences garnered from different places. that meant changing from predominantly white to predominantly black university. delaware in delaware, i carried out part of the qualitative research using face-to-face interviews in the wake of the encounters realized by most students as they navigated themselves through their academic journeys. the purpose of my interviews was to find out what views the undergraduate students held in terms of the praxis test, a form of “high-stakes” standardized test used in teacher education. unlike georgia, here i was extremely worried and curious to know why some undergraduate students would take up to six years to graduate from a bachelor’s degree program in teacher education, or never graduate even after having spent more than four years in the university. what i found depressing at times; was that some students would keep changing their majors from education to psychology or from education to social work, etc. if the changes would take place at the beginning of their academic journeys, that would make sense to me. unfortunately, most students would switch their majors after 3 to 5 years in education, and move to psychology or social work to start all over again. this was disturbing, very expensive, and counter-productive. when i sat down and asked them why they kept changing majors from education to other fields of study, especially when there is a great shortage of black teachers in us schools, the answers were chillingly similar. the students’ worst obstacle and enemy was the “high-stakes” standardized test, namely praxis in teacher education. of all students asked; 100% mentioned that the questions on this test were “culturally-unresponsive”. further, 100% of the respondents loved to become teachers, but if they failed on praxis, they would never become teachers. that led many to join other fields which did not have “high-stakes” standardized testing. one of the students remarked: “it is better to end up joining psychology or social work because nobody would ask me for praxis results”. what i found disheartening is that many students wanted to become teachers, but “highstakes” standardized testing short-changed their “dream(s)”. my qualitative research would be incomplete if i did not include into the melting pot, texas and especially dallas, which is not only predominantly hispanic, but world classcosmopolitan effects! texas in dallas, texas; the fascinating diversity of so many cultures in this metropolitan city that makes it unique. dallas is a huge city with many people speaking different languages. it is a city where one can meet someone from france, or britain, malawi, zimbabwe, bangladesh, mexico, argentina, jordan, california, new york, israel, china, indonesia, and the list is endless. for qualitative research, dallas became the bedrock of urie mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bronfenbrenner’s principles of “home visits.” the richness of this approach allowed me the researcher to look at human development across the lifespan, work with diversified respondents aged zero to 100 years old. my qualitative research included case studies; conversations, question and answer techniques, observations, detailed investigations of individuals and/or groups. homevisiting as part of my research enabled me to analyze the variables relevant to respondents under study in a relaxed discourse. the principle difference between qualitative case studies and quantitative research studies is that the focus of attention is the individual case and not the whole population of cases. most studies search for what is common and pervasive. however, in qualitative case study, the focus may not be on generalization; but on understanding the particulars of that case in its total complexity. what i found fascinating are the unique user-friendly attributes of qualitative research, for example; one of them being: “case study”; where one focuses on a bounded system, usually under natural conditions, thereby allowing the system to be understood in its own habitat. in terms of qualitative research on “high-stakes” standardized testing; events unravelling in texas at the speed of lightning became my: “aha-a, i-told-you-so moments!” wonder why? well, this would be triggered when some texas newspapers like the observer, entertained headlines such as this one: “enough is enough: texas lawmakers consider more limits to standardized testing” (savage j.; 2015). in that newspaper, savage wrote: “the anti-testing sentiment that drove lawmakers to scale back high school tests in 2013 was back”. house bill 743, by rep. dan huberty (r-houston), would reduce the amount of time students in grades three through eight spend taking state assessments. introducing the bill, it was announced: “i have petitions from over 20,000 people who have actually said we’re taking too much time on the test, we’re spending too much time on the test, we’re wasting our children’s time on the test.” rep. dan huberty (24th march, 2015). north carolina in 2015, i presented a paper on “best teaching practices, developmentally appropriate practices anchored on social justice in childhood education” at one of the historically black universities in north carolina. during my presentation on inclusion and creating culturally responsive learning environments, one of the faculty participants pointed out how it was becoming an increasing challenge for some faculty to convince graduating black students to stop using ebonics, and instead use formal english as this would affect them when writing “high-stakes” standardized tests, or getting invited to an interview, getting hired after the job interview, let alone earning sustained employability. as a question / comment that i had never expected to hear, it definitely took me off-guard. i openly admit that i love ebonics with a passion, but to find an intelligent, convincing response to that ‘unexpected ebonics comment and question,” made me feel like i was walking on pins and needles. my response was not the most palatable. know why? this is an example of a very sticky topic that would be interesting to work on qualitatively; especially that it is an extremely sensitive, taboo topic. why is ebonics of concern to higher institutions of higher learning, or teacher education college education; especially a historically black university in the midst of “highstakes” standardized testing bottlenecks? just ask as of 2015 “by the way, how are african-americans faring in the labor market these days?” talking of young or old; 16 – 24 years old; with less than high school, or with high school only, or with four years college, or those mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset who have been released from long years of jail time for minor offenses such as possessing a few grains of marijuana, or failing to pay child support while penniless, as well as other minor offenses? bear in mind that if one has a criminal background history, no matter how minor the offense; to get a job after your feet have been inside a jail or prison is a nightmare? statistically, the answer is dismal, and the numbers of unemployed african americans is stunning. (public broadcasting service, 2015). discrimination according to cnn money report of 2015 april, “unemployment for blacks fell below 10% in april for the first time since the financial crisis.” report states:“crossing that mark is a reminder of how far the economy has recovered, and how severe the recession impacted blacks in the u.s.”. more progress needs to be made for african americans. education that produces good employment results is key. a good lesson to be mindful of is that despite being almost six years into an economic recovery, the employment picture for blacks leaves a great deal to be desired if not grim in some states. did you know that blacks in illinois have an unemployment rate of 12.5%? that is more than double the national average. blacks in michigan, pennsylvania and california also have an unemployment rate above 12%; a true reality of the plight of especially blacks, according to an epi report (economic policy institute, 2015). in terms of education, some argue that: “one of the reasons the wide gap in unemployment between races can be explained by education. fewer blacks finish high school than whites, limiting their job opportunities”. evidence shows that education does not constitute answers to the whole picture. blacks with same education levels as whites still have a harder time getting a job. despite more blacks having college degrees than latinos in the u.s., latinos have a lower unemployment rate, according to labor department and census data. mystifying is that blacks with same credentials as whites and latinos also earn considerably less. the median weekly paycheck for a white college graduate in 2014 was $1,132, while a black college graduate got $895 which is over $230 less a week. overall, blacks earn less than asians and latinos as well. cnn money report (2015) states: “blacks access to employment networks and opportunities; example, job training plays a role too. discrimination among some employers, whether conscious or not, factors into the black employment picture as well”. this was also echoed in president barack obama’s eulogy speech he made in south carolina, at the funeral of reverend clementa pinckney and eight other murder victims, usa (26th june, 2015). the president spoke of better equity regrading “haves versus have-nots”, genuine empathy that not only leads to “walking in someone’s shoes”; but to “seeing worldview through their eyes.” president obama reiterated the fact that racism and discrimination does not only end with unshackling the physical slave chains, but it should end by not discriminating when it comes to inviting “johnny” to the job interview; and excluding “jamaal”; who is a black male in my opinion, while johnny would most likely be a white male. that analogy could be the explanation why many black males, educated or uneducated; are roaming about the streets unemployed, which is a travesty, bearing in mind that they would have gone through a plight of thousand bottlenecks in pursuit of education and happiness; amidst all research noises ascertaining that no child should not be left behind! mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in qualitative research, one is always reminded to be candid. quality time should not be spent by the researcher attempting to keep her/his own feelings and personal reactions out of the study. if there is relevance in the researcher’s feelings to the matter at hand, these feelings should be revealed in the form of tangible results, and for this study, i followed suit. results evidence-based qualitative research results i found: ironically, accountability has allowed standardized testing to push us students to become the victims of the “most classroom-tested children on earth”, yet unemployment is rampant as the air we breathe especially among african american students with high school diplomas or without (casualties of standardized testing). according to new york cnn money reporting (2012): “the black unemployment rate rose to 14.4% in june, a sharp contrast to the white unemployment rate, which stayed put at 7.4%. -as the overall u.s. unemployment rate stayed at 8.2% in june, the rate among black americans rose nearly a full percentage point.” what this qualitative study results reveal in terms of “high-stakes” standardized testing? 1. high-stakes standardized tests are not user-friendly because they do not provide any feedback on how to perform better. there is 100% deficiency in immediate provision of feedback as the results are not given back to the teachers and students until months later, and there are no instructions provided by test companies on how to improve these test scores. the frightening thing is that because teachers know that test scores may affect their salaries and job security, some are inclined to cheat. for example, in 2013, a fulton county grand jury indicted 35 educators from the atlanta public schools district, (georgia); and more than 20 took a plea deal. among them were teachers, principals and testing coordinators. educators were convicted april 1, 2015 of racketeering and other lesser crimes related to inflating test scores of children from struggling schools. the cheating is believed to date back to 2001, when scores on statewide aptitude tests improved greatly, according to a 2013 indictment. the indictment also stated that for at least four years, between 2005 and 2009, test answers were altered, fabricated or falsely certified. (ashley fantz, cnn breaking news, 2015). globally, the problem is catastrophic! 1(a). malpractices in “high stakes” examinations and cheating scandals internationally: similarly, international headlines dominating the far end of the globe, stated that india’s examination cheating scandals had led students to re-take the medical examinations due to cheating. in the indian state of bihar, it was reported that about 300 people had been arrested following reports of blatant cheating in school examinations. the huge number of those arrested was the students’ parents, while at least 750 students had been expelled. overall, an estimated 1.4 million students take their school exit examinations in india’s bihar alone. according to the bbc's reporter jill mcgivering: “the authorities have clearly been embarrassed by the cheating, with the episode prompting ridicule on social media. students were seen copying answers from smuggled-in note sheets, and police posted outside test centres were even seen being bribed to look the other way” (bbc world news, 9th july, 2015; new delhi). ask why?” answer: “the bottom line is that ‘tests’ are viewed as ‘extremely crucial’ for the students’ chances of gainful employment, successful career, and a happy life ever after”. in 2008, india’s mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset outcry read: "if our country is to progress we must maintain high educational standards, and this is only possible if malpractices in examinations are curbed with an iron hand," the india’s supreme court said (tewary, a. 2013. bbc news,bihar, india). let us continue to look at what my qualitative study results. 2. high-stakes standardized tests fail to value individual differences and creativity. for those who value howard gardner’s multiple intelligence theory, the joy of teaching is thwarted. that innovative student who writes a more creative answer in the margins of “high-stakes” standardized test, is robbed of credit from his/her creative response. this is because computers grade these “high-stakes” standardized tests, and sadly a creative response that does not follow the machine’s format; is marked as a wrong response, even when that answer is authentic from a super genius perspective. ever wondered why so many of our “right-brained”, creative students end up roaming the streets jobless? think the correct answer is: “bad teacher, poor student, failing school? if your answer is yes, “think again!” 3. high-stakes standardized tests negatesand ridiculesdiversity. a wide range of differences exists in the people who take the same “high-stakes-fits-all” standardized tests. students subjected to these tests have different cultural backgrounds, different levels of proficiency in the english language, different learning and thinking styles, family backgrounds, past experiences, disabilities and abilities, income levels, health statuses, ways of decoding information, coping skills of working under timed examination pressure and so on. some students thrive under pressure like tea in hot water and others will have a brain freeze the moment their examiner(s) announces: “start your examination now!” others are excellent in rote learning such that when the examination is placed before them, their memory sets in photographic mode, while those who are not gifted with that talent will go blank in that examination room. it is an open secret that the “high-stakes” standardized tests treat students as if they were all identicalto the group that took the test several years ago, and to which the test would be “normed” against any future test-takers to be compared). see why some educators see it as set up for failure? 4. high-stakes standardized tests favor those who have high socio-economic advantages at the expense of “have-nots.” that fact is a no-brainer. test companies (a multi-billion dollar a year industry) not only manufacture these tests at the exclusion of the teachers’ or educators’ input, and they also manufacture the courses as well as programs that are specially tailored for practice prior to the final examination, in order to “prepare for the final test.” when parents have the money, they have the capacity to even get special tutors to help their off spring to do well on the test. what then happens to poor antonio, pedro, esmeralda, rosa, john, belinda, kevin, muchaneta, chamunorwa, hamunyare, jailin, jamaal, and rushnik from low income parents, poor neighborhoods and stigmatized zip codes? those students would be doomed to fail dismally on the “high-stakes” standardized tests. if parents do not have the money, the school for their offspring would obviously be located in a low socio-economic zip code, an area that would end up getting less funding than that of rich suburban schools. consequently, when poor parents fail to purchase for their children the preparation exam-kit for the same “high-stakes” standardized test as what those at the higher socio-economic levels do, income inequality gets propagated for generations to come. 5. high-stakes standardized tests place unprecedented emphasis on standardized test results; forcing teachers to spend a huge amount of targeted time “teaching to the test.” if there is something that is interesting, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset compelling, useful, or otherwise favorable to the development of a student’s understanding of the world, but it is not going to be on the “highstakes” standardized test, there really is not any incentive to cover that material. instead, most of classroom time consists of either drilling for tests, or taking the tests. this dismisses the possibility of innovative teaching and learning anything new or important. example, because common core and the no child left behind law (nclb) only tests reading, math, and science at the expense of music, creative art, social studies, physical education, history, moral education, vocational subjects like home economics, fashion and fabrics, carpentry, painting, drawing, gymnastics, religious education, anger management, good grooming, gardening, flower arrangement, yoga, dance, nature study, geography and numerous other subjects are completely neglected. ever wondered why there is way too much violence and bullying in the schools these days? education has lost its salt! 6. high-stakes standardized tests occur in an artificial learning environment: the environment resembles a pressure cooker. the tests are timed, students are not allowed to talk to each other, no questions should be asked, students cannot use references or learning devices, and they cannot get up and move around. question: “when does the real world operate likewise? are you not persuaded to think of the prison set-up? i do.” the irony of all this is the fact that when politicians and policy-decision makers talk about education, they garnish their speeches with statements like: “education must prepare our students for the real world.” clearly, the results i found show that “high-stakes” standardized testing compromise and negate that notion. 7. high-stakes standardized tests promote stress: we know stress causes obesity, hypertension, bullying, school fights, anger, diabetes, and even stroke. some students are blessed to have high coping skills when subjected to a high degree of stress. others are not so lucky, and stress would consume them to a point where they would act like “zombies”, and when that happens, they fall prey to peer pressure, gun violence, drug abuse, problems with law enforcement, and consequently end up filling the jail / prison cells. when school becomes one of the main sources of students’ stress, education-wise, the level of the playing field becomes obscured. brain research suggests that too much stress is psychologically and physically harmful. cruelly, when stress becomes overwhelming, the brain shifts into a “fight or flight” response, where it is impossible to engage in the higher-order thinking processes necessary to respond correctly to the “high-stakes” standardized test questions. 8. high-stakes standardized testsdemean and degrade the richness of human experience and human learning to a number or set of numbers. a student might be a super genius in a particular subject, for instance music or painting, but will never receive appraisals, affirmation, or room to blossom because his or her test score in math and reading might be extremely low. if that particular student were to be given a chance to thrive on her natural talents; example to draw a picture, or lead a group discussion, or create a hands-on project, or public speaking, he/she could have earned an a pertaining to those skills and knowledge. what high-stakes standardized tests do to students of this category is to simply dehumanize, belittle and fail. 9. high-stakes standardized tests provide some parents and some teachers with a false sense of security: example; when a student scores well on a test, it is assumed that they know the material, but this might be fairly untrue. the student might have simply memorized the fact or formula or trick necessary to do well on the test because some students are naturally gifted in taking standardized tests, others are not. this mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset argument is supported by a research carried out on a group of harvard graduates who were asked why it is colder in the winter and warmer in the summer. most of them got the question wrong. they were good testtakers but they did not understand fundamental principles that required a deeper comprehension (gardner, h. 2000). in his book, renowned psychologist argues: “k-12 education should strive for a deep understanding of three classical principles: truth, beauty, and goodness. such an understanding requires mastery of the major disciplines that human beings have created over the centuries. as powerful examples of his approach, gardner describes an education that illuminates the theory of evolution, the music of mozart, and the lessons of the holocaust” (howard gardner, 2000). 10. high-stakes standardized tests do seem to augur well with some political figures, some administrators, and the test companies that make billions in financial revenues. on the rough end of the rope, are poor educational outcomes, disadvantaged failing students, pinkslipped educators with labels which say “bad teachers” and the stigmatized failing schools. reality is that education is usually an election gimmick which allows some politicians to get elected by promising “better education and test results”, if elected into office. to some teachers and administrators, this has become a bait to get “extra or much-needed” funding and avoid harsh the “high-stakes” penalties by embarking on unscrupulous corruption of cheating and boosting test scores. my research results strongly indicate that while adults in the education arena might be benefitting, students are persistently hurting emotionally, psychologically and otherwise. most students confess that they dislike and dread “highstakes” standardized testing. the only problem is that listening from concerned adults is beyond the horizon, if any. 11. high-stakes standardized testing creates a culturally pervasive learning environment consisting “winners” and losers.” the losers are those students whose teachers refer to them with labels such as “my low students”, “my learning disabled kids”, “my retards or slowlearners.” simultaneously, winners are made to become entrapped in superiority complex and belief that they are the “chosen ones, super geniuses in the making”. once students get caught up in this pseudo tread mill of achievement, that pushes their super-ego to the limit and they will be forced to do whatever it costs, to stay at that super-imposed status, and that is what drives some students to embark on cheating during examinations, a habit that they might take on for the rest of their lives. the losers suffer loss of self-esteem, and the damage of “low expectations”. the winners suffer loss of soul, since most of them are trained seals performing for fast-track parents and may reach midlife on a pinnacle of power and achievement, yet lack any connection to their deeper selves, to ethical principles, to aesthetic feelings, to spiritual aspirations, to compassion, creativity, and/or commitment to life. 12. high-stakes standardized testing does not only stress out the teachers and students. parents of the students are not spared from stress either. example, case study of indian state of bihar, which reported that about 300 people had been arrested following reports of blatant cheating in school examinations, and the huge number of those arrested werestudents’ parents (bbc, 2013). for every parent out there, when it comes to their children’s education and examinations, it becomes the “david-goliath” moment, adrenalin just shoots abnormally high, causing exceedingly high levels of stress, which may lead to stroke and heart attacks to all affected by the misery. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset discussion judging teachers' effectiveness solely on the basis of end-of-year test scores, without regard to where the teachers' students started at the beginning of the year, is tantamount to “highstakes” standardization. before making judgments about individual teachers, it requires sophisticated analyses to sort out how much growth is probably caused by individual teachers. example, students who are frequently absent tend to have lower scores regardless of the quality of their teacher, so it is vital to take into account how many days students are present in order to be fair and to provide trustworthy estimates of teacher effectiveness. the trustworthiness of a value-added measure depends on how it is defined and calculated. valueadded measures require complicated formulas that take into account as many influences on student achievement. research a growing number of researchers are studying whether value-added measures can do a good job of measuring the contribution of teachers to test score growth. koretz (2008) argues that measuring the value added by the teacher requires knowing not only how much students have learned in a given year, but also the rates at which those particular students learn. rothstein (2008) worries that test score gains are biased because students are not randomly assigned to teachers. for example, comparing teachers whose classrooms are treated as dumping grounds for troubled students with teachers whose classrooms contain the best-behaved students will favor the latter. for example, in recent years more school reformers, elected officials, and policy makers have been calling for the application of “value-added measures” on teacher pay (including bonuses), as well as hiring, firing, and tenure decisions, to be partly based on student test scores. schools tests results may be used to trigger penalties for schools, including negative public ratings, the replacement of staff members, firing or transferring some or all of a school’s administrators and faculty, or forcing a school to pay for additional services and transportation costs for students, assigning a–f letter grades to schools, or even closure. fair to point out that: " high-stakes standardized tests somehow or somewhat corner the teacher and the students in a tightly closed, remote controlled locked box whose keys are nowhere to be found, hence disallowing both the teacher and the student to work outside the box" (aaron a. &tsiwo-chigubu, m. 2005). high-stakes standardized testing is analogous to bottle-necks, no wonder this is a problem that has triggered protests in the world of academia in the usa. for example, in 2013 grafield high school in seattle, washington; teachers refused to administer (map) the measures of academic progress (armstrong 2013). in a study by aaron and tsiwo-chigubu (2005); "overwhelmed teachers were found to be eliminating recess totally to make more time for rote learning in preparation for standardized tests instead". no wonder obesity among us school children is rampant as standardized testing plays a part to it. aaron and tsiwo-chigubu’s (2005) study was conclusive to the fact that standardized tests have deplorable and negative impact on low income neighborhoods that obviously might be in abject poverty and lacking basic resources, while high income neighborhoods would obviously have schools that would be filthy rich in school supplies. those discrepancies would definitely leave "poor children behind". the study questions: "what happens if children in these under-privileged communities fail those tests?” truth is: those teachers get coined as "bad teachers", then receive pink slips; followed by loss of the teaching jobs. affected students mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset are further humiliated by having their school labeled as "poor performing", the school would lose funding, and in extreme case-scenarios, the school gets condemned and is shut down. this action research highlighted "stigma" as the number one stressor when a community finds itself in a situation deemed as “failing students, with bad teachers, in a failing school, within a given community and school district.” what the research found is that later on in higher grades, when students get standardized tests, they are aware that test scores may affect their future lives, therefore they would do whatever it takes to pass them, including cheating and taking performance drugs (e.g. psychostimulants like ritalin “borrowed” from their friends) (aaron a.&tsiwo-chigubu, m. 2005; and armstrong t. 2013). further, protests around the country against standardized testing include those at garfield high school in seattle, washington, where teachers refused to administer the measures of academic progress (map), as reported by armstrong (2013).having analyzed all these facts, it is imperative to alleviate students’ plight of the endless bottlenecks including standardized testing, which by the way; has trickled down to touch the kindergarten, if not the pre-k classroom too! these bottlenecks do not only hinder success during school going years, but they actually haunt the victims into the job market, resulting in dismally high targeted unemployment figures; which become astronomically high especially among low income blacks. conclusions hooray! finally, the us department of education has begun to smell the rat! as an author, researcher, educator, advocate, and parent; i am shocked. flabbergasted seems too light a term! how on earth would it possibly take the department of education 13 years to decipher, and figure out what university faculty members, teachers and student teachers denounced as “flawed accountability that is equally an over-kill for teachers and students, plus a set up for failure” for teachers and students alike? truth of the matter is that when you and i get to walk in the shoes of teachers in terms of teacher-student ratios, performance, accountability, good teaching, bad teaching, good learning opportunities, job security; and high-stakes standardized tests; we should ask ourselves this question: “high five or chest bump?” education and politics as preparations are under way for 2016 us presidential elections, participants embrace the notion one man, one woman, one vote; there is no better topic in question than that of education! badly needed is a reform in education’s glitches as those rampant in “high-stakes standardized testing”, let alone with introduction of the “common core” in education. i would wind up by stating that this article unravels the tip of the iceberg intended to explore a persistent problem of “high-stakes” standardization testing, whose effects have been somewhat swept under the carpet with the hope that the problem would simply go away. it intends to expose to light some of those nuances, whose silence has been without challenge, for which the public and professional analysis, and school improvement efforts have been to some extent “falsely” forthcoming. “truth is not only violated by falsehood; it may be equally outraged by silence.” -henri frederic amiel (webster’s book of quotations, 1992). given today’s scrutiny of how education plays in the public domain, this article invites each and every 2016 us presidential candidate; to read and take heed. that means former us secretary of state hillary clinton (new york), vice president joe biden: (delaware), donald trump, us senator bernie sanders (vermont), mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset former governor martin o’ malley (maryland); former us senator jim webb (virginia), us senator marco rubio (florida), former governor lincoln chafee (rhode island),former governor jeb bush (florida), dr. ben carson (florida),governor chris christie (new jersey), us senator ted cruz (texas), former governor bob ehrlich (maryland),former irs commissioner mark everson (mississippi), businesswoman carly fiorina (virginia), former governor jim gilmore (virginia), us senator lindsey graham (south carolina), former arkansas governor mike huckabee (florida), governor bobby jindal (louisiana), governor john kasich (ohio), former governor george pataki (new york),us senator rand paul (kentucky), former governor rick perry (texas), former us senator rick santorum (pennsylvania),businessman donald trump (new york), governor scott walker (wisconsin), according to google, 2015. final concluding statement word of caution: do not get me wrong. i love standardized tests, “low stakes” of course, and not “highstakes”, which definitely get loaded with draconian rules that tend to be an over-kill to students, teachers, parents, employers, researchers, and many; in the world of academia.i would end my story with the following: “all truths are easy to understand once they are discovered; the point is to discover them”. – galileo galilei (1632). will 2016 us presidential campaigns rescue education? references amarnathtewary, (2013). india 'cheating' students expelled in bihar. (bbc news, 20th march, 2013. patna, bihar, india). aaron, a. &chigubu, m. (2006). present day students a.k.a. victims of standardized testing. national forum of teacher education journal – electronic, 16, 3. fantz, a. (2015). prison time for some atlanta school educators in cheating scandal.(cnn breaking news, 2015). art, j. (2015) president obama eulogy at clementa pinckney funeral service. emanuel african methodist episcopal church founded in 1816 by african american former members of the methodist episcopal church in charleston, south carolina, usa.washington journal television, [accessed on 26th june, 2015]. available from world wide web:https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+servicec-span 2 (2015). gardner h. (2000). the disciplined mind: beyond facts and standardized tests; the k-12 education that every child deserves. gardner. google search (2015). the 2016 us presidential candidates[20th july, 2015]available from world wide web: https://www.google.com/?gws_rd=ssl#q=us+presidential+election+2016 mailto:topacademicjournals@gmail.com https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=cspan+%282%29++washington+journal+television%2c+%282015+june+26th%29 .++president+obama+eulogy+at+clementa+pinckney+funeral+service https://www.google.com/?gws_rd=ssl#q=us+presidential+election+2016 https://www.google.com/?gws_rd=ssl#q=us+presidential+election+2016 academic journal of science, engineering and technology vol.8, issue 1; january febuary 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset galilei, g. (1632). the dialogue concerning the two chief world systems. copernican. jacob, e. (1988). qualitative research: adefense of traditions. review of educational research. 59, 2, 229 – 235. john savage (2015). enough is enough: texas lawmakers consider more limits to standardized testing. the texas observer[22nd july, 2015]available from world wide web:http://www.texasobserver.org justin rowlatt (2015). inquiry ordered after 'thousands' accused over india exam scandal. (bbc news, 9th july, 2015.asia). koretz, d. (2008). a measured approach: value-added models are a promising improvement, but no one measure can evaluate teacher performance. american educator, 18–27 ,39. mcgivering, jill (2015). india arrests hundreds over bihar school cheating. (bbc world news, india. 21 march, 2015). new york cnn money (2012).http://money.cnn.com/ public broadcasting service (2015).http://www.pbs.org/topics/news-politics/ richek, m.a.; caldwell j. s.; jennings, j. h. & lerner, j.w. (2002). reading problems: assessment and teaching strategies. allyn rosenthal r. &jacobson l. (2013). pygmalion in the classroom: teacher expectation and pupils’ intellectual development. crown house publishing house ltd. rothstein, j. (2008). student sorting and bias in value added estimation: selection on observables and unobservables. (working paper no. 170). princeton, nj: princeton university and cambridge, ma: national bureau of economic research. smith (1983). quantitative vs qualitative research: an attempt to clarify the issue. american educational research association. educational researcher. vol. 12, no.3 (march, 1983), pp. 6-13. us department of labor, bureau of labor statistics (2015).http://www.bls.gov/ces/ u.s. department of education, no child left behind act (2001). http://www2.ed.gov/nclb/landing.jhtml?src=rn u.s. department of education, national center for education statistics. washington, dc. ... condition of education (2012).https://nces.ed.gov/ wilson, v. (2015). projected decline in unemployment in 2015 won’t lift blacks out of the recession-carved crater. economic policy institute (2015). mailto:topacademicjournals@gmail.com http://www.texasobserver.org/ http://www.texasobserver.org/ http://money.cnn.com/ http://money.cnn.com/ http://www.pbs.org/topics/news-politics/ http://www.pbs.org/topics/news-politics/ http://www.bls.gov/ces/ http://www.bls.gov/ces/ http://www2.ed.gov/nclb/landing.jhtml?src=rn http://www2.ed.gov/nclb/landing.jhtml?src=rn https://nces.ed.gov/ https://nces.ed.gov/ academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset evaluation of hand-dug well suitability for drinking and agricultural purposes in blama, small-bo chiefdom, eastern, sierra leone fatima mansaray, jonathan kpaka, and musa kamara department of chemistry, school of environmental sciences njala university, sierra leone. doi: https://doi.org/10.5281/zenodo.10592545 abstract: this research investigates the microbial and physicochemical characteristics of five local hand dug wells used for drinking and agricultural activities in blama, small-bo chiefdom, in the kenema district, eastern province of sierra leone. these five local hand-dug wells were randomly selected based on the availability of water in them throughout the year. the physical characteristics examined are: ph, turbidity, conductivity, temperature, total dissolve solid (tds); and the chemical characteristics, such as: residual chlorine (r. chorine), magnesium, potassium, nitrite, iron, fluoride, ammonia, copper; and the microbial characteristics include: total coliforms, fecal coliform and non-fecal coliform. samples were collected in 500 ml sterilized plastic containers and transported to the laboratory, within 30 min. the results analysed indicate that the physical and chemical characteristic are within the who guideline limits for safe drinking water. however, a large amount of nonfaecal coliform was recorded in all the water samples analysed which exceed the world health organization standard for non-faecal coliform ((<10), and with no presence of residual chlorine. it can therefore be concluded that the water sample analyzed was potable and fit for drinking and agricultural activities. keywords: hand-dug, well, local, safe and sample. introduction globally, 2.2 billion people lack access to safely managed drinking water at home (who/unicef, 2019). safe drinking water is defined as "water with microbial, chemical and physical characteristics that meets who guidelines or national standards on drinking water quality (who/unicef, 2019). according to who, for water to be qualified as being ―safely managed‖, drinking water must meet three criteria: be accessible on the premises, be available for at least 12 h/day, and be free from escherichia coli, arsenic, or fluoride contamination. who/unicef (2017) report stated that an estimated 5.3 billion people had access to safely-managed drinking water, of that number, 1.4 billion used basic services, 206 million used limited services, 435 million used unimproved sources, and the remaining 144 million relied on untreate surface water. according to world water development report (2019) on the disparities between the rich and the poor, on a global scale, half of the people who drink water from unsafe sources live in africa. in sub-saharan africa, only 24% of the populations have access to safe drinking water, and 28% have basic sanitation facilities that are not mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset shared with other households (unicef/who, 2017). access to clean and safe water continue to be a major challenge for citizens of sierra leone. the water aid (2017) report stated that more than six out of 10 people in sierra leone do not have safe water and eight out of 10 people do not have access to a decent toilet. as a result, over 1,200 children under five die each year from waterborne disease in sierra leone. a recent publication by world bank (2020) stated that access to safe water in sierra leone was reported at 1 in 2020, according to collection of development indicators. access to an improved water source is currently defined as the percentage of the population that can obtain at least 20 l/person/day from an ―improved‖ source that is within 1 km of the user’s dwelling. access to clean and safe water remains an eyesore for rural and urban settlements across sierra leone. a lot of people inhabiting in rural communities of sierra leone heavily depend on hand-dug well. the preference of groundwater as a source of drinking water in rural areas is because of its relatively better quality than river water (obiri-danso et al., 2009). the country is blessed with six months of wet season and six months of dry season, during wet season (may to october) most people get their drinking and domestic water from the rains which reduced the burden on people in search of water for drinking and domestic purposes. in the dry season (november to april), the availability of potable water sometimes poses a major challenge for most families. the urban settlements such as bo, kenema, and makeni seldomly received potable water from the sierra leone water company (salwaco) and guma valley water company for the capital freetown. water is an essential part of human nutrition and is required for maintenance of personal hygiene, food production and prevention of diseases (thliza et al., 2015). it is absolutely necessary for most life driven processes (aroh et al., 2013). quality water is colorless, tasteless, odourless, as well as free from faecal contamination (opara and nnodim, 2014). blama is the chiefdom headquarter of small-bo, with an estimated population of 8,146, according to statistics sierra leone (ssl, 2021 population census of cities/towns). before the start of the civil war in march, 1991, there were pipe borne water facilities at principal roads of blama. but as a result of the 10-year civil war, most of the government infrastructures and water channels were destroyed, leaving the wreckages as existential evidence of today’s monument. the availability of clean and safe drinking water has become a major issue at blama. at present, the major sources of available drinking water at blama are hand-dug well, river water, swamp water, hand pump wells and streams. the dug well is a traditional method of withdrawing groundwater from the upper layer of a water table by constructing a well of large diameter, typically lined by concrete rings and enclosed by a concrete slab or metal sheet with ventilation (howard et al., 2006; bain et al., 2014). in rural areas of developing countries, the great majority of health-related water quality problems are the result of bacteriological or other biological contamination (who, 1997). a similar report published by statistics sierra leone (stats ssl, 2017), with the technical support of unicef, conducted a multiple indicator cluster survey (mics) to collect internationally comparable data on a wide range mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of indicators. the survey revealed that almost 90% of the drinking water at household level contained the e. coli bacteria, presenting a serious health threat to citizens. the poor and marginalized people living in rural and peri-urban settlements are most in need for improved and safe drinking water, appropriate forms of sanitation and access to water for other domestic purposes (crow, 2001). studies carried out in different areas of the world indicate that most of the sources of domestic water have an alarming level of microbiological pollution (mpakam, 2009; oladipo et al., 2009; prasanna and reddy, 2009; kuitcha et al., 2010; khaniki et al., 2010; oyedeji et al., 2010). in 2012, there was a cholera outbreak in sierra leone, according to who report (2012), there was 18,919 cases reported with 273 deaths. cholera is a water borne disease that is caused by drinking contaminated water. report from epidemiology (cdc, 2012) research has shown that cholera is predominant in sub-saharan africa where clean water and sanitation remains a major problem. the objective of this study was to examine, the bacteriological and physicochemical characteristics of five local hand dug wells consumed at blama, small-bo chiefdom, in the kenema district, eastern province of sierra leone, and hence find a suitable remedy to help improve the quality of these residential wells and also ensured that water quality test is conducted on all residential wells before it is being consumed. materials and methods description of study area blama is the chiefdom headquarter town of small-bo, in the kenema district, eastern sierra leone. it lies approximately 12 miles away from kenema. it is found on latitude 7° 52' 29" n and longitude 11° 20' 43" w. blama is a fairly big town with an estimated population of 8,146 (ssl, 2021 population census of cities). the major activity of the people of this community is farming and animal husbandry. five hand dug wells drawn from five different locations, were selected for this study. the five hand dug wells were selected for this research base on the availability of water in the well throughout the year. google map locator was used to map out the sample collection site. the description of the sample collection area is illustrated in figure 1. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1. a map showing the area of study. description of sampling area five local hand dug wells located at blama, small-bo chiefdom, in the kenema district were selected for this research at random. the names of the five wells are as follows: 5 koribondo road well, 4 jimmy section well, 6 jabbie street well, 3 jabbie street well, and 19 koribondo road well. these five hand dug wells were used by the locals of that community for drinking and agricultural activities. the study started in december, 2020, and run through may, 2021, a six months intensive water quality examination. these five hand dug wells were selected for this research based on the availability of water in them throughout the year without drying up. sampling a sterilized cup with a string tied to the cup was used to collect water from the well. the sterilized container was rinsed three times with the water sample to be tested for. the water sample was centrally poured into the sterilized container (500 ml), to avoid water touching the inside mouth surface of the container, in order to avoid contamination. the water sample was then transported to the laboratory (directorate of water resources, in the ministry of water resources, bo city) for physicochemical and bacteriological assessment. sample collection and analysis physical parameters the analysis for the physical parameters was conducted according to instructional manual (wagtech international, we30210). total dissolve solid and electrical conductivity mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in the examination of electrical conductivity (µs/cm) and total dissolved solids (mg/l) of the water sample, a digital conductivity with electrode was employed to determine the concentration of tds and ec after the electrode was switched on and duplicate values recorded. a clean tissue paper was used to wipe the electrode dry before being reused. ph a digital ph meter with electrode was used to measure the ph. it was done by inserting the electrode into the water sample and the electrode turned on, the values were taken in duplicates. turbidity a photometer, 7100 was used. in the determination of the level of turbidity, a blank solution was prepared to calibrate the photometer. a test tube containing 10 ml of water was placed in the basin and covered with light black cap and power turned on. duplicate values were recorded. it is measured in nephelometric turbidity unit (ntu). temperature the examination for temperature was done by placing the digital thermometer into the water sample and electrode switched on; duplicated values were recorded in °c. chemical characteristics determination wagtech photometer, 7100, was used to investigate the chemical characteristics. before the analysis, references were drawn from the operational manual. a blank solution (reference, 0.00 mg/l) was first prepared to calibrate the photometer. a test tube containing 10 ml water sample was placed one tablet (chemical), it was then crushed and stirred to allow a homogenous mixture and allowed to stand for 10 min for full colouration. it was then inserted in the cell holder and lid closed. the photometer was adjusted to the appropriate wavelength and power turned on, the concentrate of each sample was recorded in mg/l. microbial determination total coliform count, e. coli, and faecal coliform 500 ml of each of the five samples collected from the wells was transported to the water quality directorate for the examination of e. coli, faecal coliform and non-faecal coliform. who permissible standard for the presence of faecal coliform in water is 0 count/100 ml. the membrane filtration method was used to assess the bacteriological parameters, after the culture media had been produced. the water samples were allowed to pass through a membrane pore space of 0.45 µm, bacteria were trapped on the membrane surface. the membrane was placed in a petri dish containing ―m-faecal coliform broth (park scientific limited)‖ and was incubated at 44°c for 18 to 24 h. examination was done based on colour indicator, blue-green for e. coli and pink for nonfaecal coliform colonies. results and discussion the results of the physicochemical and bacteriological parameters of the five hand dug wells used for drinking and agricultural activities were presented in statistical methods (mean, variance, and standard deviation). the results of the various samples are illustrated in tables 1 to 5. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset physicochemical parameters from the results, the mean temperature of all the water samples was examined. 5 koribondo rd (28.62°c), 4jimmy section (28.12°c), 6jabbie street (28.50°c), 3 jabbie street (28.32°c) and 19 koribondo road (28.52°c) fell outside the world health organization (who) permissible limits. who does not have any temperature standard for safe water, but recommended that safe water must have a temperature of 25°c at a ph of 7. environmental factors such as soil nature, the depth of water level and other anthropogenic matters can influence the temperature of drinking water. weather patterns have also been known to increase or decrease the temperature of water. in water quality examination, temperature plays a pivotal role in influencing both the absorption of chemical and the multiplication of microbial organism. the mean ph obtained for all the water samples (tables 1 to 5) was analysed: 5 koribondo road (6.67), 4 jimmy section (6.64), 6 jabbie street (6.30), 3 jabbie street (6.55), and 19 koribondo road (6.73), fell within the who permissible limits, except the 6 jabbie street water sample, that recorded a low ph mean value. who recommended that drinking water should have ph of 6.5 to 8.5. an increased carbon dioxide concentration may therefore lower ph, whereas a decrease may cause it to rise (who, 2003). the ph of most raw water lies within the range of 6.5 to 8.5 (who, 2003). from tables 1 to 5, the mean electrical conductivity and the total dissolved solids for all the water samples were analysed: 5 koribondo road (129.38 µs/cm, 63.63 ppm), 4 jimmy section (145.07 µs/cm, 72.72 ppm), 6 jabbie street (158.52 µs/cm, 79.30 ppm), 3 jabbie street (114.85 µs/cm, 57.08 ppm), and 19 koribondo road (95.03 µs/cm; 47.08 ppm) fell within the who permissible limits. who recommended standard for electrical conductivity and the total dissolved solids in drinking water is <450 µs/cm and <248 ppm, respectively. from tables 1 to 5, the mean turbidity value for all the water samples examined was: 5 koribondo road (0.04 ntu), 4 jimmy section (0.04 ntu), 6 jabbie street (0.69 ntu), 3 jabbie street (1.04 ntu), and 19 koribondo road (0.38 ntu) fell within the who acceptable limits. who standard for turbidity of acceptable water drinking was <5.0 ntu. from tables 1 to 5, the chemical characteristics for all the water samples examined fell within the who permissible limits for safe water. the chemical characteristics for the various wells were as follows: 5 koribondo road (r. chlorine 0.00 mg/l, magnesium 6.33 mg/l, potassium 1.73 mg/l nitrite 0.11 mg/l, fluoride 0.01 mg/l, iron 0.02 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 4 jimmy section (r. chlorine 0.00 mg/l, magnesium 11.33 mg/l, potassium 2.52 mg/l, nitrite 0.06 mg/l, fluoride 0.01 mg/l, iron 0.01 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 6 jabbie street (r. chlorine 0.00 mg/l, magnesium 11.67 mg/l, potassium 2.30 mg/l, nitrite 0.32 mg/l, fluoride 0.06 mg/l, iron 0.00 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 3 jabbie street (r. chlorine 0.00 mg/l, magnesium 2.27 mg/l, potassium 1.07 mg/l, nitrite 0.28 mg/l, fluoride 0.00 mg/l, iron 0.00 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 19 koribondo road (r. chlorine 0.00 mg/l, magnesium 12.33 mg/l, potassium 2.07 mg/l, nitrite 0.52 mg/l, fluoride 0.01 mg/l, iron 0.01 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l). all the chemical parameters analysed are within the who limits. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset microbial parameters e. coli and faecal coliform tables 1 to 5 show no presence of e. coli and faecal coliform in all the water samples examined, 5 koribondo road (0.00 cfu/100 ml, 0.00 cfu/100 ml), 4 jimmy section (0.00 cfu/100 ml, 0.00 cfu/100 ml), 6 jabbie street (0.00 cfu/100 ml, 0.00 cfu/100 ml), 3 jabbie street (0.00 cfu/100 ml, 0.00 cfu/100 ml), 19 koribondo road (0.00 cfu/100 ml, 0.00 cfu/100 ml). non-faecal coliform the results from tables 1 to 5 show a high mean value of temperature table 1. hand dug well at 5 koribondo road, blama. month standard parameter mean variance who dec. jan. feb. march april may deviation temperature (°c) 28.20 26.90 30.00 29.60 28.60 28.40 28.62 1.21 1.09 no value ph 6.19 7.74 6.80 6.52 6.72 6.02 6.67 0.37 0.61 6.5-8.5 conductivity (µs/cm) 94.00 163.9 173.00 76.30 94.00 175.10 129.38 49.54 7.04 tds (ppm) 47.00 81.80 86.40 38.10 47.00 81.50 63.63 474.57 21.78 248 turbidity (ntu) 0.00 0.00 0.00 0.24 0.00 0.00 0.04 0.08 0.28 r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.3-0.5 magnesium (mg/l) 6.00 6.00 8.00 0.00 8.00 10.00 6.33 11.87 3.44 potassium (mg/l) 2.00 2.12 2.14 2.14 0.00 2.00 1.73 0.73 0.85 nitrite (mg/l) 0.12 0.12 0.14 0.02 0.14 0.12 0.11 0.00 0.02 fluoride (mg/l) 0.02 0.00 0.00 0.01 0.01 0.01 0.01 0.00 0.02 iron (mg/l) 0.03 0.02 0.01 0.02 0.02 0.01 0.02 0.00 0.01 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 no value copper (mg/l) 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 12.00 12.00 16.00 14.00 14.00 12.00 13.33 2.67 1.63 <10 cfu/100 ml table 2. hand dug well at 4 jimmy section, blama. month standard parameter mean variance who dec. jan. feb. march april may deviation mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset temperature (°c) 28.10 26.20 30.00 28.80 28.10 27.50 28.12 1.61 1.27 no value ph 5.68 7.74 6.74 6.86 6.68 6.14 6.64 0.49 0.69 6.50-8.5 conductivity (µs/cm) 172.10 135.4 111.80 145.90 172.00 133.20 145.07 466.31 21.59 450 tds (ppm) 86.60 67.60 55.90 73.10 86.60 66.50 72.72 146.65 12.11 248 turbidity (ntu) 0.00 0.00 0.00 0.23 0.00 0.00 0.04 0.01 0.09 5.0 r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.30-0.50 magnesium (mg/l) 12.00 10.00 10.00 12.00 10.00 14.00 11.33 2.67 1.63 potassium (mg/l) 2.64 2.66 2.60 2.60 2.40 2.20 2.52 0.03 0.18 nitrite (mg/l) 0.06 0.06 0.10 0.06 0.04 0.02 0.06 0.00 0.03 fluoride (mg/l) 0.01 0.01 0.00 0.01 0.00 0.00 0.01 0.00 0.01 iron (mg/l) 0.01 0.01 0.00 0.00 0.01 0.00 0.01 0.00 0.00 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 no value copper (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100ml non-faecal coli 16.00 14.00 14.00 16.00 16.00 14.00 15.00 2.40 1.55 <10cfu/100m non-faecal coliform in all the water samples analysed: 5 koribondo road (13.33 cfu/100 ml), 4 jimmy section (15.00 cfu/100 ml), 6 jabbie street (13.00 cfu/100 ml), 3 jabbie street (12.33 cfu/100 ml), and 19 koribondo road (12.83 cfu/100 ml). the mean values of all the five samples examined fell outside who permissible limits. who permissible limits for non-faecal coliform is <10 cfu in 100 ml. the high concentration of non-faecal coliform in the water samples could be associated with environmental factors such as soil nature, decay of organic matter, and leakage from septic tank. a similar study conducted to determine the bacteriological contamination of ground water sources, revealed that non-faecal coliforms were found in all the wells and boreholes sampled analysed (jeremiah and jonathan, 2018). traditionally, total coliform bacteria have been used to indicate the presence of fecal contamination; however, this parameter has been found mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 14.00 12.00 14.00 14.00 12.00 12.00 13.00 1.20 1.09 <10 cfu/100 ml turbidity (ntu) 2.00 2.00 2.00 0.26 0.00 0.00 1.04 1.11 1.05 <𝟓 . r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.3-0.5 magnesium (mg/l) 16.00 14.00 12.00 14.00 14.00 12.00 13.67 2.27 1.51 < 𝟎𝟎.𝟎 potassium (mg/l) 2.46 2.70 0.00 2.74 2.24 2.20 2.06 1.07 1.03 nitrite (mg/l) 0.06 0.16 0.14 1.14 1.16 0.16 0.47 0.28 0.53 fluoride (mg/l) 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.00 iron (mg/l) 0.04 0.02 0.01 0.01 0.02 0.01 0.02 0.00 0.01 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 copper (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 12.00 12.00 12.00 14.00 12.00 12.00 12.33 0.67 0.82 <10 cfu/100 ml table 4. hand dug well at 3 jabbie street, blama. parameter month mean variance standard deviation who dec. jan. feb. march april may temperature (°c) 28.30 26.10 30.00 29.40 28.60 27.50 28.32 2.00 1.42 no value ph 5.63 7.59 5.97 6.76 6.63 6.70 6.55 0.47 0.68 6.5 8.5 conductivity ( µs/cm) 151.00 107.10 106.60 56.20 151.00 117. 20 114.85 1237.42 35.18 tds (ppm) 75.50 53.90 53.10 28.10 75.50 56.40 57.08 308.97 17.58 < 𝟐 𝟒 𝟖 no value mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to exist and grow in soil and water environments and is therefore considered a poor parameter for measuring the presence of pathogens (stevens et al., 2003). total coliform bacteria are not acceptable indicators of the sanitary quality of rural water supplies, particularly in tropical areas where many bacteria of no sanitary significance occur in almost all untreated supplies, (who, 1997). an exception is e. coli, a thermotolerant coliform, the most numerous of the total coliform group found in animal or human faeces, rarely grows in the environment and is considered the most specific indicator of fecal contamination in drinking-water (who, 2004). the presence of e. coli provides strong evidence of recent fecal contamination (who, 2004, stevens et al., 2003). from figure 2, the highest conductivity and told dissolved solid was recorded by table 3 (hand dug well at 6 jabbie street, blama) followed by table 2 (hand dug well at 4 jimmy section, blama). the highest ph was recorded by table 5 (hand dug well at 19 koribondo road, blama) and the lowest by table 3 (hand dug well at 6 jabbie street, blama). all the chemical parameters measured fall within the who permissible standards. from figure 3, the highest non faecal coli was recorded by table 2 (hand dug well at 4 jimmy section, blama), followed by table 1 (hand dug well at 5 koribondo road, blama), the lowest was recorded by table 5 (hand dug well at 19 koribondo road, blama). all the non faecal coliform recorded for the five wells fell above the who permissible bracket (non-faecal coliformis <10 cfu in 100 ml. the high level of non-faecal coliform in all the five samples could be as a result of contaminated water or animal waste that moves quickly down the groundwater, resulting in the variation of non-faecal coliform level. conclusion the objective of this research is to determine the potability of five hand dug wells used for drinking and agriculture activities in blama, small-bo chiefdom, kenema district, eastern, sierra leone. in as much as safe drinking water plays a fundamental role in the life of all living organisms, it is therefore incumbent on us all to maintain its hygienic component properly. from the results of the analysis, it can be said that the physicochemical and microbial parameters of all the water samples examined are within the who permissible limits, except for the non-faecal coliform presences in all the water samples analysed which exceed the who limits and the lack of residual chlorine in all the water samples. it can therefore be concluded that all the water samples examined are safe and fit for drinking. conflict of interests the authors have not declared any conflict of interests. references aroh kn, eze em, ukaji d, wachuku ck, gobo ae, abbe sd, teme sc, igoni ah (2013). health and environmental components of sachet water consumption and trade in aba and port harcourt, nigeria. journal of chemical engineering and material science 4(2):13-22. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bain r., cronk r, wright j, yang h, slaymaker t, bartram j (2014). fecal contamination of drinking-water in low-and middle-income countries: a systematic review and meta-analysis. plos medicine 11(5):e1001644. crow b (2001). water: gender and material inequalities in the global south. howard ahmed g, shamsuddin mf, mahmud af, deere sgd (2006). risk assessment of arsenic mitigation options in bangladesh. journal of health, population and nutrition 24(3):346-355 jeremiah kt, jonathan aqb (2018). bacteriological contamination of groundwater in relation to septic tanks location in ashanti region, ghana. kuitcha d, ndjama j, tita am, lienou g, kamgang k, beyala v, ateba bh, ekodeck ge (2010). bacterial contamination of water points of the upper mfoundi watershed, yaounde, cameroon. african journal of microbiology research 4(7):568-574. khaniki grj, zarei a, kamkar a, fazlzadehdavil m, ghaderpoori m, zareim a (2010). bacteriological evaluation of bottled water from domestic brands in tehran markets in iran. world applied science journal 8(3):274-278. mpakam hg (2009). vulnérabilité à la pollution des ressources en eaux à bafoussam et incidences socioéconomiques et sanitaires: modalités d’assainissement.th. doct. phd, univ. yaoundé i. p 267. opara au, nnodim j (2014). prevalence of bacteria in bottled and sachet water sold in owerri metropolis. international journal of science innovations and discoveries 4(2):117-122. oladipo ic, onyenike ic, adebiyi ao (2009). microbiological analysis of some vended sachet water in ogbomoso, nigeria african journal of food science 3(12):406-412. obiri-danso k, adjei b, stanley kn, jones k (2009). microbiological quality and metals in wells and boreholes water in some peri-urban communities in kumasi, ghana. african journal of environmental science and technology 3(3):059-066. oyedeji o, olutiola po, moninuola ma (2010). microbiological quality of packaged drinking water brands marketed in ibadan metropolis and ileife city in south western nigeria. african journal of microbiology research 4(1):096-102. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset prasanna rb, reddy ms (2009). bacteriological examination of drinking water with reference to coliforms in jeedimetla, hyderabad, india. african journal of biotechnology 8(20):5506-5507. stevens m, ashbolt n, cunliffe d (2003). recommendation to change the use of coliform as microbial indicators of drinking water quality. australia government national health and medical research council. thliza la., khan au, dangora db, yahaya a (2015). study of some bacterial load of some brands of sachet water sold in ahmadu bello university (main campus), zaria, nigeria. international journal of current science 14:91-97. sierra leone (stats ssl) (2017). multiple indicator cluster survey. https://www.unicef.org/sierraleone/media/391/file/slmics-report-2017.pdf.pdf sierra leonean (2012). cholera outbreak wikipedia.https://en.wikipedia.org/wiki/2012_sierra_leonean_cholera_outbreak cdc (2012). treatment and prevention in sierra leone zainab blell mph student. https://slideplayer.com/slide/12371900/ world bank (2020). report on access to water in sierra leone. who/unicef ( 2019). joint monitoring programme (jmp) for water supply, sanitation and hygiene. who/unicef (2017). joint monitoring programme. progress on household drinking, sanitation and hygiene (2000-2017). world health organization (who) (2004). guidelines for drinking water quality, 3rd ed. volume 1. recommendations. world health organization – geneva. world health organization (who) (2003). guidelines for drinking-water quality, 2nd ed. vol. 2. health criteria and other supporting information. world health organization, geneva, 1996.world health organization (1997). guidelines for drinking-water quality —2nd ed. geneva. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset computational fluid dynamics (cfd) simulation of a gas-solid fluidized bed: residence time validation study baru debtera chemical engineering department, college of biological and chemical engineering, addis ababa science and technology university, p. o. box no16417, addis ababa, ethiopia. doi: https://doi.org/10.5281/zenodo.10592547 abstract: in this work, the business computational fluid dynamics (cfd) is used for the numerical simulations of an air-solid fluidized bed container in the solid phase involving a multi-fluid eulerian multiphase model and the kinetic theory of granular flow (ktgf). the height of the fluidized bed setup is 1.5 m while its diameter is 0.2 m. with it, a series of experimentations were obtained using helium tracer to determine the residence time distribution (rtd) at various normalized velocities, that is, mixing of air-solids at different degrees. 2 and 3 dimensions of the fluidized bed container are simulated. the main purpose of this study is to understand the hydrodynamic behavior of air-solid fluidized bed container through a framework of eulerian multiphase model and to analyze the hydrodynamic behavior of the air-solids mixing. as a first approach, the cfd model is validated using the experimental results of the residence time study. the numerical results of rtd corresponded well with the experimental findings. this shows that the cfd modeling might be used to indicate the performance of a fluidized bed reactor. keywords: computational fluid dynamics, fluidized bed, residence time distribution (rtd), gas-solids mixing, turbulence. introduction fluidization is the process whereby dense particles change into a fluid-like state over suspension in fluid. fluidization entails delivering a flow of gas through a bed of granular substance at an adequate velocity, with the granulated bed being liquefied (gidaspow, 1994; richardson et al., 2008). fluidized beds are common equipment in the industry and are used for catalytic reactions, increasing of size, element covering methods, heating system/chilling, drying, and mixing (kunii and levenspiel, 1991). gas-solid fluidized beds are advantageous in many processes involving heat and/or mass transfer between phases. they provide efficient mixing, which results in excellent gas-solid contact and relatively uniform temperature/concentration profiles within the bed (cui and grace, 2007; gidaspow, 1994). indeed, the need for cleaner and sustainable energy source has led to the development of biomass gasifiers which employ fluidized bed technology. it is a hopeful tactic that specifies quick biomass central heating, effective heat, mass transfer and uniform reaction temperature (salaices et al., 2012). understandably, the physics behind mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fluidization indicates theimportance of variable quantity such as pressure changes, minimum fluidization velocity, solid volume fraction profile, and particle velocity profile (benzarti et al., 2012; taghipour et al., 2005). usually, fluidized bed reactors are chaotic in nature (li et al., 2009). this is indicated by a turbulent fluidized bed. in addition, a fluidized bed is an intermediate that takes place in a chemical reaction involving gas and solid. the fluidized bed is mainly selected for the mixture of solid catalyzed gas segment reactions because it can regulate the temperature of the reaction zone well, and the situations in fluidized bed reactors are approximately isothermal. nowadays, computational fluid dynamics (cfd) is a powerful device used for the complex phenomena amongst air and solid element segments in the fluidized bed. cfd can be used to solve navier-stokes equations and has become a helpful device for investigating and developing different flow systems. computational properties have improved substantially with sharp declining expenses, allowing the acquisition of detailed computational information about reactions and flows at a fraction of the cost of the corresponding experiments (dutta et al., 2010). it is possible to define a computational domain in which the geometry of the fluidized bed reactor can be incorporated and cfd approach can be used to solve the governing navierstokes equations, using appropriate initial and boundary conditions. the results obtained from the numerical model can then be compared to experimental data for a necessary validation. since computational assets have expanded significantly at forcefully diminishing costs, specified computational data about the flow can, these days, be acquired even with cheap experiments (xia and sun, 2002). the transient cfd simulations are performed to suggest the usability of the multiphase approach for the prediction of the solid phase mixing and residence time distribution in the riser (andreux et al., 2008). transient solution is always necessary because of the unsteady state nature of the fluidized bed. cfd is useful in understanding the quantitative hydrodynamics of fluidization and is needed for the design and scale-up of efficient reactors in several processes industries. the systematic method used to estimate the performance of a supplier and inclusive mixing actions of a fluidized bed entails quantifying and examining the residence time distribution (rtd) of the solid segment (pant et al., 2014). the gas mixing in circular fluidized bed risers is evaluated as an overall behavior. the total mixing conduct is considered by determining the set time delivery of a gas tracer inserted at the feed inlet. the knowledge of rtd function is very important for the optimization of the operating parameters and equipment configuration (idakiev and morl, 2013). the tracer is introduced at the inlet and monitored at the outlet of the column. the concentration of tracer is introduced as a pulse into a fluidized bed column at the feed inlet. then, the samples are collected at the exit at fixed time intervals until tracer concentration goes to zero at the outlet (lopez-isunza, 1975). using cfd, the flow of inert tracer units is determined using species transport equation, where the diffusion coefficient of elements, that is, the necessary parameter indicating particle diffusion capacity is investigated (hua et al., 2014). typically, a cfd study should be conducted on a pilot scale fluidized bed, and numerical methods are used as prototypes of the experimental arrangements and to confirm the experimental outcomes. the main goal of this effort is to use the cfd program available in ansys fluent application to simulate the hydrodynamic performance of a fluidized bed. a first approach of the full-fledged cfd model is important to prove the modeling mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset through the investigational results presented. due to the availability of residence time data, the cfd model is first validated with the rtd information obtained experimentally. the present study is divided into two main: validation of the twoand three-dimensions simulation of gas-solid fluidized bed with the rtd data and a subsequent study to identify the flow patterns of fluid-solid flow in the turbulent fluidized bed reactor. the numerically predicted rtd outcomes are associated through the experimental results of lopez-isunza (1975). the target is to make a meaningful comparison between the predictions of the rtd at three different airflow rates that give the normalized velocity(u0 /umf 9.5;8.0 and 6.4) . note that the minimum fluidization velocity is 0.634 cm/s. computational fluid dynamics (cfd) model geometry and mesh for the cfd simulations, initial mesh needs to be created. this mesh creates a geometry in which the calculations occur and furthermore is divided into several volumes according to the finite-volume methodology. these calculations are governed by the so-called reynold’s averaged navier-stokes (rans) equations. dimensions of the fluidized bed reactor (1.5 m height and a radius of 0.1 m) are simulated. the particle diameter used in the gas-solid fluidized bed is between 175 and 200 µm and falls in the geldart group b particles (geldart, 1973). the geometry is made in both 2d and 3d. the mesh consists of 12357 elements in 2d and 35616 elements in 3d, respectively. the mesh of the fluidized bed is as shown in figure 1 as 2d and 3d. as shown in figure 1, the initial bed height is fixed at 0.5 m. the solid particles can be seen over the distributor plate. the gas inlet is at the bottom and the gas outlet is at the upper part. a tracer monitoring point is also at the top outlet. gas-solid model figure 1. mesh of the geometry of the fluidized bed reactor, as 2d mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 3 for solutions in finite volume, an arrangement of balance and 3d, respectively. equations is numerically solved for fluid flow over a number of control volumes, that is, over the so-called mesh cells. these balanced equations, calculated via the rans approach for the conservation of mass, momentum and energy were used for cfd simulations. these equations are already implemented in the cfd software ansys fluent® version 16.2. the cfd replication of the bed hydrodynamics is founded on the perception of eulerianeulerian different phase flow prototypical incorporated in the kinetic theory of granular flow (ktgf) (gidaspow et al., 2004; tartan and gidaspow, 2004). this engineering method invented since the theory for non-ideal dense gases was developed by chapman and cowling (1970) is used for nearby solid segment calculations. a brief explanation of the underlying theory related to ktgf is subsequently discussed. conservations of mass the sum of volume fraction for gas and solid phases must be equal to unity: g s 1 (1) where a subscript g and s stand for gas and solid phases. the continuity equation for a gas phase and a solid phase are expressed as follows: ( g g .( g t (2) ( s s .( s sv) 0 t conservation of momentum the momentum equation for the gas (g) phase is given as follows: t ( g gvg) .( g gvgvg) g p g g gg kgs (v g vs) (3) momentum equation for solid phase: t ( s svs) .( s svsvs) s p ps s s sg kgs (v g vs) (4) gas phase shear stress tensor, g g g( vg vt g ) (5) solid phase shear stress tensor, s s s( vs vs t ) s( s s) vs. (6) the solid phase stress tensor consists of a shear viscosity and a bulk viscosity; it arises from solid particle momentum exchange due to kinetics and collision. a frictional viscosity is considered for viscous-plastic ) 0 g v mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset translation. it occurs when a solid phase reaches the maximum volume fraction. the sum of collisional, kinetic and frictional viscosities gives the solids shear viscosity ( s s, col s, kin s, fr ). solid collision viscosity (syamlal et al., 1993): s, col s sdgp o, ss(1 ess)( )1 s /2 (7) solid kinetic viscosity (syamlal et al., 1993): 6(3 s sedp) 1 2 sgo, ss(1 ess)(3ess 1) (8) s, kin s 5 ss solid frictional viscosity (schaeffer, 1987): ps s, fr sin (9) 2 2d where φ is the angle of internal friction. solid bulk viscosity (lun et al., 1984): 4 1/2 (10) s s sdpgo, ss(1 ess)( )s 3 solid pressure is implemented according to ps s s s 2 sgo, ss(1 ess) s 2 s (11) radial distribution function is implemented according to 1 go, ss 1 ( s, max ) 1/3 s (12) where the restitution coefficient for particle-particle impacts, ss is static at 0.9 for all the simulations in the present work. this value is taken from literature studies (balakin et al., 2012; hu et al., 2010) on glass and polymer elements (in this study polymeric silica gel is used). wen-yu and gidaspow drag models are used for the momentum conversation coefficient. the gidaspow effort model equation is a mixture of wen-yu and ergun equations. drag function mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3 kgs 4cd dp g g s2.65 g vg vs (13) drag function (gidaspow model, 1994): kgs 150cd sd 2.g (1 g) 1.75 dg p g vg vs for g p g 0.8 (14) when g 0.8 , gidaspow drag model becomes wen-yu model. 24 0.687 cd re 1 (0.15 g res) g s and d p re s g vg vs . g the coarse temperature is calculated by changeable kinetic energy equivalence for the particles, following the kinetic theory of granular flow (ktgf) belief. to require co×llisional energy dissipation, s, outstanding to inelastic collisions of elements and the granular conductivity, ks, the equation is given as: 3 t s s s s : vs ks s (15) 2 vs2 is the granular temperature. a list of sub-models used for the cfd model and their values are shown in table 1. to simulate these equations inside the fluidized bed, various boundary conditions are required. the simulations in this study are done using gas phase (air) with density of 1.225 kg/m3 and viscosity of 1.785×10-5 pa s and solid phase with particle diameter between 175 and 200 µm, and density of 2400 kg/m3. for tracer gas (helium), the density and viscosity are 0.165 kg/m3 and 2.0×10-5 pa s, respectively. gas-solid mixing studies gas-solid fluidization is divided into several regimes depending on gas speed. in this study, the gas rate used falls within the bubble fluidized bed regime, that is, the range of reynold number (re) between 0.2 and 1000. air mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bubbles increase in the fluidized bed; there is continuous transference of gas to the solid phase by diffusion and convection modes. the gas that enters the fluidized bed passes through the granular particles in the column. the bubble pushes through the bed of the solid particles and stops at the top. accordingly, the bubble is like the cloud table 1. summary of the numerically simulation boundary conditions and model parameters. descriptions sub-model granular viscosity granular bulk viscosity frictional viscosity lun et al. (2009) granular temperature ktgf drag law gidaspow (1994) inlet boundary condition velocity inlet outlet boundary condition pressure outlet wall boundary condition no slip for air parameter values bed height 0.5 m volume fraction of solid phase 0.577 operating pressure 101325 pa gas inlet velocity (0.065, 0.051 and 0.041) m/s turbulent kinetic energy 0.30554 m2/s2 turbulent dissipation rate 0.30553 m2/s3 angle of internal friction 30° particle-particle restitution coefficient 0.9 specularity coefficient for solid phase 0.001 of dense segment, in which the gas is continuously transferred by convection inside the bubble. in the cloud, the contact between solid and gas takes residence. this implies that air exists in the cloud, which flows back to the bubble again. part of it might be exchanged with the solid phase by diffusion or adsorption with the solid that is exchanged with the emulsion phase. convection and diffusion mechanisms of exchange occur simultaneously. the gas exchange among bubble and suspension phases has been described in terms of mass transfer coefficient by kunii and levenspiel (1991): 1 dna k cab cae (16) mailto:topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset intrfacial area dt where k is mass transfer coefficient (cm/s). interchange rate is defined as, 1 dna k cab cae (17) volume dt where k is mass transfer coefficient (s-1). kunii and levenspiel (1991) expected two transference steps, namely the transfer among bubble void and cloud particles intersection area and that between the cloud particles intersection area and the emulsion phase. they also presumed that the mass transfer quantity of bubblecloud and cloud-emulsion is given as in terms of gas transfer quantity per unit volume of bubble void. umf d1/2 g1/4 kbc 4.5 db 5.85 db 5/4 from bubble to cloud (18) mf ub de 1 / 2 kce 6.78 db3 from cloud to emulsion (19) they defined the overall gas transfer coefficient of the bubble phase and emulsion phase as follows: kbck ce kb (20) kbc kce from the thorough information regarding the method of fluid (gas) in the cloud, it can carefully be expected that the gas structure in the cloud is roughly uniform. chiba and kobayashi (1970) used the analysis of murray for the flow pattern around the spherical bubble to obtain the following expressions for the interchange coefficient: 6.78 d mf u b (21) kb 3 db equation 23 indicates that there is no effect of the diffusion coefficient of the transferring species, nor any direct effect of the fluid mechanical phenomen. however, in this study, gidaspow and wen-yu gas-solid interchange coefficients are used to observe the conduct of the hydrodynamics in a fluidized bed. species transport model 1 g db finally, kobayashi et al. (1967) determined the rate of 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset species transport equation is used for the residence time distribution (rtd) study. the conservation equation for the species predicts the residence mass portion of each species, yi, through the solution of a convection and diffusion equation from ith species. the general conservation equation is given as follows: i . vyi ji ri si (23) t where i is density of species i, is velocity vector, is diffusion change of species i, ri is the net rate of creation of species by chemical reaction and si is the rate of creation by accumulation from the dispersed phase. in this situation, chemical reaction is not considered; therefore ri and si are ignored and equation 24 is reduced to: i . vyi ji 0 (24) t where the diffusion flux of the species for turbulent flow is calculated by fick’s law and cfd uses the dilute estimate of fick’s law for prototypical mass diffusion due to the concentration difference and temperature. the diffusion flux might be given as follows: ji .yi di, m sct t dti tt (25) i where sct is the turbulent schmidt number sct dt while the temperature gradient is negligible and combines equations 25 and 26 form given as: exchanges of species at the inlets involves both convection and diffusion elements and compounds. that means the convection constituent is made static by the quantified inlet species mass fraction, while the diffusion factor depends on the difference of the calculated species’ amount (which is not known priori). turbulent modeling in various industrial processes related to fluidization, turbulence behavior is observed. k -ε model is the commonly used engineering turbulent classical for industrial applications; it is robust and reasonable accurate. in this study, a standard kε model is used to calculate the transportation equation for turbulent kinetic energy (k) and dissipation rate of the turbulent kinetic energy (ε). the k-ε model is given as follows: exchange by measuring the rtd in a fluidized bed. they di, m sctt . (26) concluded that the interchange parameter could be i . vy i .y i expressed as: t 11 during the simulation, diffusion at the inlet is important kb . (22) because the pressure -based solver calculating the net 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset .( mkvm) .( t, m k) gk, m m (27) .( mkvm) .( t, m k) (c1 gk, m c2 m ) (28) k where is turbulent (eddy) viscosity computed from k k2 – ε, ( t, m mc ) where c =0.09, c 1=1.44, c 2=1.92, =1 and gk, m is classical of turbulent kinetic energy due to velocity difference. residence time distribution (rtd) residence time distribution (rtd) study is significant to describe the mixing and flow rate patterns of the inner apparatus, and to determine whether the unit would be an ideal apparatus in the future, that is, tubular reactor or mixed flow reactor. besides, rtd is used to prototype the reactor as a mixture of ideal reactors. residence time distribution data values are used to investigate any nonidealities similar to directing, by transient and quick circuiting existing in the reactor (levenspiel, 1999). it can also be used to measure up or to project a reactor once the kinetics is attained. to accomplish rtd replications, the transient examination of a tracer is measured with the same physical properties as that of incessant phase. the t xj xj xj sct (29) where t is a turbulent viscosity and is given k2 as t mc , and ytr is mass fraction of tracer species. numerical procedure for hydrodynamics mathematical method ansys fluent answers the main integral equations for mass conservation, conservation of momentum, kinetic theory of granular flow and turbulent simultaneously. this technique is used for finite volume approach for flow arrangements. pressure based problem solver method transportation calculation for the mass flow rate of a modeling. notwithstanding, tactically estimate of initial turbulent flow can be written thus: conditions confirms the meeting of the solution. they are two kinds of initial conditions: solids volume fraction in the di, m t ] bed and ythe solid capacity fractions in the freeboard are initially -velocity of the air phase in the fluidized bed. mytr m vm y tr [ ytr 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset pressure-based calculation employs phase momentum equations, collective pressure, and calculations of phase volume fractions in a separate way. the phase uses an implicit technique for pressure connected equations (pcsimple). an extension of the simple system is established for polyphase flows. this consists of modifying the pressure and velocity which are functional to improve the limitation of the volume continuously. three or two dimensions discretization finite volume system used to conduct complex geometries is functional. the differentiation of the convective rate is first order exposed. under transient formulation, the restricted second order implicit is used; this preparation would offer well stability, for time discretization to continuously confirm the bound variables. the bounded second order implicit is a better option for the fluidized bed to obtain stability and accurate results. a first order implicit transient design by means of the phase-couple simple method is used to calculate the equations for both 2-dimensional and 3-dimensional cases. initial values and boundary values conditions the initial condition might not influence the stable state solutions that may be favorable for the fluidized bed set to zero (assuming only gas). the y-velocity of the gas phase in the fluidized bed is computed completely with a steady state volumetric fluxes balance in which the flow rate going to the fluidized bed segment is linked to the volume flow rate leaving the fluidized bed segment (consisting of both solids and gas phase): vinuin vgug (30) vinu in ug (31) vg the situations represent that the superficial velocity of the gas is a proportion of the bed volume to the feed inlet volume which is identical with the void fraction: u ug in (32) g boundary conditions: at the inlet of the fluidized bed, there is gas superficial velocity for primary phase, while the secondary phase is zero inlet velocity. at the outlet of the fluidized bed there is atmospheric pressure. no slip, wall boundary condition is applied to the gas phase, while the partial slip condition is applied to the solid phase. a specularity coefficient (ϕ = 0.001) for a partial slip model is used based on the suggestion of shi et al. (2015). problem description and cfd method problem identifications figure 1 is the conceptual representation of the fluidized bed that is modelled and simulated using software. this figure characterizes a cylindrical container, that is, the gas-solid fluidization bed with superficial air velocity inlet at the bottom of the column. the solid particles are patched with s =0.577 at the initial bed height (ho) = 0.5 m. the fluidizing gas causes the gas-solids mixing. the gravitational effect on the particles bed is taken into account as the bed is vertical. simulation procedure the assumption of the tracer does not involve any chemical reaction with the reactants to produce any product. the smallamount of tracer component has the same physical properties with the working fluid. that means the flow rate is not troubled inside the reactor after the tracer is presented. this assumption is used in many literature 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset studies (hua et al., 2014; shilapuram et al., 2011). the rtd analysis such as mean residence time, change, and leaving age distribution can be done. the tracer gas injection method involves: firstly, run the steady statesimulations for the flow rate and turbulence as shown in table 1, for physical properties and boundary conditions. it may be noted that the residuals of the continuity, momentum, k-turbulent kinetic, dissipation rate kinetic energy reduce in reaching steady state conditions. after it is achieved, it converges for the steady state simulation; the mass fraction of the tracer is made to 1 and the other equations are disabled. the tracer carries the properties of helium gas, as mentioned in the experimental setup (lopez-isunza, 1975). now the unsteady state equation for the tracer (equation 29) is used for one iteration to imitate the pulse method after which the mass fraction of the tracer is changed to 0. the flow equations (conservation of mass, conservation of momentum, k-turbulent kinetic, dissipation rate kinetic energy species transport and tracer gas) are solved. then, the mass density of the tracer is time monitored when leaving the fluidized bed. results and discussion cfd reproductions of the fluidized bed are obtained by rtd validation study done by comparing the results with the experimental study done by lopez-isunza (1975). gas-solid hydrodynamics hydrodynamic characterization of gas-solid fluidized bed simulated by cfd in 2d with the drag equations of gidaspow and wen-yu is done. figure 2 represents the time used for the solids velocity profile in the radial path at 0.3 m. the motoring height is chosen arbitrarily but care is taken to ensure that it is below the top elevation of the fluidized bed. this is done to ensure that the gassolids mixing behavior is certainly investigated. it can be seen that the simulation results using gidaspow and wen-yu gas-solid drag models are slightly different from each other. the solids axial velocity fluctuations along the radial position are larger in wen-yu model than in gidaspow model. experimental studies (li et al., 2009; loha et al., 2012) indicate that the variation in solids -0.10 -0.05 0.00 0.05 0.10 0.0 0.1 0.2 0.3 0.4 0.5 0.6 wen-yu model gidaspow model radial position(m) figure 2 . time averaged (10 s) simulation of solid particles ( a) axial velocity along the radial height of 0.3 m and (b) velocity contour. 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset velocity is similar to that exhibited by gidaspow drag model. this indicates that the gidaspow model could be more accurate in predicting the gas-solid solid hydrodynamics in this study. moreover, gidaspow drag equation is a modified form of wen-yu (and ergun) drag equations as explained earlier. figure 3 illustrates the time-averaged solid capacity fraction variation along the center of the fluidized bed. it shows the extreme solids volume fraction model equation of wen-yu ( s = 0.63) compared to the model of gidaspow ( s = 0.59). this specifies the wen-yu model equation promotes solids clustering as compared to the gidaspow model. it is probably due to the huge gas velocity escaping along the walls thereby pushing the solid particle together and forming cluster. figure 4 indicates the profile of timeaveraged solid volume fraction outlined in the radial position at height of 0.4 m by gidaspow and wen-yu drag models. fraction contour in the fluidized column. the solids volume fraction shows even distribution along the radial direction for both models, while wen-yu model indicates comparatively larger variation of solids volume fraction along the radial direction as compared to gidaspow model. to conclude from the aforementioned three figures, gidaspow model seems to be preferable to we-yu model as it indicates less variation along the radial and axial direction in gas and solid velocity. also, literature studies (sahoo and sahoo, 2015; loha et al., 2012; hooyar et al., 2012) appreciate gidaspow model for evaluation with investigational data. it must also be noted that the gidaspow model is a modification of ergun and wen-yu models. residence time distribution (rtd) validation the species transport model in ansys fluent® used for the simulation of set time delivered (rtd) is implemented for the fluidized bed in 2d and 3d, respectively. in the rtd study, helium gas is considered as tracer gas. the concentration of the gas is measured when it is leaving, and the residence time predictions are given as mean time distribution:t citi t i (33) ci ti exit time distribution: e t c t (34) ci ti three cases with air velocities ranging from 6.4 to 9.5 times the minimum fluidization velocity are simulated in this presented work. that means they are indicated as ratio of u0 /umf which is 0.634 cm/s. in all the three cases (u0 /umf 9.5;8.0 and 6.4) , both the 2d and figure 5. experimental and predicted rtd response of the fluidized bed under normalized velocity conditions(u0 /umf 9.5). 0 20 40 60 80 100 0 100 200 300 400 500 time (s) 3d cfd result 2d cfd result experimental data predicted by prof.felipe 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6. experimental and predicted rtd response of the fluidized bed under normalized velocity conditions (u0 /umf 8.0). 3d simulation results are in line with the experimental data (figures 5 to 7, respectively) especially at lower simulation times; while it seems to over-predict the experimental data as the simulation time proceeds in the end. this is probably because of the numerical discrepancies associated with the cfd model while obtaining the final tracer concentration at the outlet. however, the peaks from the experimental data fit well with the numerical model, although the peaks from the 2d simulations are slightly lower than the peaks from the 3d simualtions. this is probably because in 3d, tracer has enough space to pass through the fluidized bed. the validation of residence time distribution studies seems to be in line with the experimental study of lopezisunza (1975) for the three different velocity conditions investigated (figures 5 to 7). the theoretical mean residence time of the air in column is predicated in kunii g h g and levenspiel (1991) as t . the results are u0 summarized in table 2 for an initial solids bed height of 0.5 m. for u0 /umf 9.5, the average residence time is the fastest (compared to u0 /umf 6.4 which is the slowest), which means that the mass transfer between the bubbles and emulsions phase is comparatively faster. conclusion the gas-solid hydrodynamics using computation fluid dynamics (cfd) is important to identify the rate behavior of the inner fluidized column. the cfd implemented in this simulation work is a eulerian-eulerian multiphase flow fixed with the kinetic theory of granular flow and standard turbulence model used for closure. the two drag models, necessary for gas-solid interchange coefficient, that is, the gidaspow and wen-yu models, simulate the gas-solids mixing in the bed. although there is not much difference between the performance of these two models, gidaspow model is recommended as it is able to correctly capture the hydrodynamics inside the fluidized bed. the simulations results studied are timeaveraged distributions of gas and solids velocity along the axial and radial directions. the simulation results related to residence time distribution (rtd) for three different velocity rations (u0 /umf 9.5;8.0 and 6.4) , that is, at different degrees of gas-solids mixing, are evaluated in both 2-d and 3-d. the results are similar with the investigational data of lopez-isunza (1975). however, further research is still needed to understand the mass transport among the bubble and emulsion phases and connect them to the gas-solid hydrodynamics. it is important to investigate the relation between the mass transport and the residence time distribution, to have a meaningful fluidized column reactor. conflict of interests the author has not declared any conflict of interests. 0 20 40 60 80 100 120 0 100 200 300 400 time (s) 3d cfd result 2d cfd result pred. by prof. felipe experimental data 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references andreux r, petit g, hemati m, simonin o (2008). hydrodynamic and solid residence time distribution in a circulating fluidized bed: experimental and 3d computational study. chemical engineering and processing: process intensification 47(3):463-473. balakin b, hoffmann ac, kosinski p (2012). the collision efficiency in a shear flow. chemical engineering science 68(1):305-312. benzarti s, mhiri h, bournot h (2012). drag models for simulation gassolid flow in the bubbling fluidized bed of fcc particles. world academy of science, engineering and technology 61:1138-1143. chapman s, cowling tg (1970). the mathematical theory of nonuniform gases: an account of the kinetic theory of viscosity, thermal conduction and diffusion in gases. cambridge university press. chiba t, kobayashi h (1970). gas exchange between the bubble and emulsion phases in gas-solid fluidized beds. chemical engineering science 25(9):1375-1385. cui h, grace jr (2007). fluidization of biomass particles: a review of experimental multiphase flow aspects. chemical engineering science 62(1-2):45-55. dutta a, ekatpure rp, heynderickx gj, de broqueville a, marin gb (2010). rotating fluidized bed with a static geometry: guidelines for design and operating conditions. chemical engineering science 65(5):16781693. geldart d (1973). types of gas fluidization. powder technology 7(5):285-292. gidaspow d (1994). multiphase flow and fluidization: continuum and kinetic theory descriptions. boston: academic press. gidaspow d, jung j, singh rk (2004). hydrodynamics of fluidization using kinetic theory: an emerging paradigm. powder technology 148(2-3):123-141. hu x, zhang j, dong c, yang y (2010). simulation of dense gas-solid fluidized bed based on two-fluid model. in 2010 asia-pacific power and energy engineering conference (pp. 1-4). ieee. hua l, wang j, li j (2014). cfd simulation of solids residence time distribution in a cfb riser. chemical engineering science 117:264282. idakiev v, morl l (2013). study of residence time of disperse materials in continuously operating fluidized bed apparatus. journal of chemical technology and metallurgy 48(5):451-456. kobayashi h, arai f, sunagawa t (1967). kagaku kogaku (chemical engineering, japan) 29:858. kunii d, octave l (1991). fluidization engineering. 2. ed. butterworthheinemann series in chemical engineering. boston: butterworthheinemann. 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset levenspiel o (1999). chemical reaction engineering (3rd ed). new york: wiley. li p, lan x, xu c, wang g, lu c, gao j (2009). drag models for simulating gas–solid flow in the turbulent fluidization of fcc particles. particuology 7(4):269-277. loha c, chattopadhyay h, chatterjee pk (2012). assessment of drag models in simulating bubbling fluidized bed hydrodynamics. chemical engineering science 75:400-407. lopez-isunza f (1975). determination of interchange parameter in fluidized beds using pulse testing techniques. m.eng thesis, mcmaster university, canada. pant hj, sharma vk, goswami s, samantray js, mohan in, naidu t (2014). rtd in a pilot-scale gas–solid fluidized bed reactor using radiotracer technique. journal of radioanalytical and nuclear chemistry 302(3):1283-1288. richardson jf, harker jh, coulson jm, richardson jf (2008). particle technology and separation processes (5. ed.). oxford: butterworth heinemann. sahoo p, sahoo a (2015). a comparative study on effect of different parameters of cfd modeling for gas– solid fluidized bed. particulate science and technology 33(3):273-289. salaices e, de lasa h, serrano b (2012). steam gasification of a cellulose surrogate over a fluidizable ni/αalumina catalyst: a kinetic model. aiche journal 58(5):1588-1599. schaeffer dg (1987). instability in the evolution equations describing incompressible granular flow. journal of differential equations 66(1):19-50. shi x, sun r, lan x, liu f, zhang y, gao j (2015). cpfd simulation of solids residence time and back mixing in cfb risers. powder technology 271:16-25. syamlal m, rogers w, o'brien tj (1993). mfix documentation. national energy technology laboratory, department of energy, technical note no. doe/mc31346-5824. taghipour f, ellis n, wong c (2005). experimental and computational study of gas–solid fluidized bed hydrodynamics. chemical engineering science 60(24):6857-6867. tartan m, gidaspow d (2004). measurement of granular temperature and stresses in risers. aiche journal 50(8):1760-1775. wen cy, yu yh (1966). mechanics of fluidization. chemical engineering progress symposium series 62:100111. xia b. sun dw (2002). applications of computational fluid dynamics (cfd) in the food industry: a review. computers and electronics in agriculture 34(1):5-24. academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assessment of plastic waste and wealth in abakaliki urban area, south east nigeria. 1obuka esther njideka (ph.d), chukwuenye agatha tochukwu, & ani stephen chukwunonso department of geography & meteorology, faculty of environmental sciences, enugu state university of science & technology. department of building, faculty of environmental sciences, enugu state university of science & technology. doi: https://doi.org/10.5281/zenodo.11122156 abstract the study examined the assessment of plastic waste and wealth in abakaliki urban area, south east nigeria. the specific objective sought to; examine the effect of plastic lifecycle analysis on the wealth creation and evaluate the effect of environmental impact on the wealth creation in abakaliki urban area, south east nigeria. the study adopts a quantitative study. a primary source of data was adopted for the study. a well structure questionnaires was use to collect data. the questionnaires were design in line with a five-point likert scale. the data was analysed using the structural equation modeling technique with the aid of smartpls 4.0. the study revealed that plastic lifestyle has significant positive effect on wealth creation given that β=0.218 and p <0.001. while environmental impact has significant positive effect on wealth creation given that β=0.240 and p <0.001. the study concluded that the assessment of plastic waste has significance positive effect on the wealth in abakaliki urban area, south east nigeria. we recommended that the government should identify and invest in companies that are actively adopting sustainable and eco-friendly plastic alternatives. with the growing global focus on environmental responsibility, businesses in this sector are likely to experience increased demand, leading to potential returns for investors. keywords: assessment, plastic, waste, wealth 1.1 introduction the proliferation of plastic waste has emerged as a pressing global environmental challenge, demanding rigorous attention and innovative solutions. in the urban centers of developing nations, such as abakaliki in the south east of nigeria, the issue of plastic waste management poses a multifaceted dilemma. rapid urbanization and population growth have led to increased consumption and disposal of plastic products, placing significant strain on local waste management systems. simultaneously, urban areas often exhibit disparities in wealth distribution, exacerbating the challenges of equitable plastic waste management. assessing the relationship between plastic waste and wealth within the context of abakaliki urban area offers a critical lens through which to comprehend the complex dynamics of urban environmental sustainability and socioeconomic disparities. this research endeavor seeks to investigate the intricate interplay between plastic waste generation, disposal practices, and the socioeconomic status of residents in abakaliki. by understanding how plastic waste is produced, managed, and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset perceived across different wealth strata, we aim to provide valuable insights that can inform policy, community engagement, and sustainable development initiatives. plastic waste, characterized by its durability and persistence in the environment, has far-reaching ecological consequences, including the contamination of water bodies, harm to wildlife, and contributions to greenhouse gas emissions when incinerated. at the same time, the management of plastic waste has direct economic implications, as efficient waste collection and recycling systems can create job opportunities and support local industries. however, these benefits are often distributed unevenly, with marginalized communities facing greater environmental burdens and fewer economic benefits. wealth distribution in urban areas is an equally pertinent issue, as it influences access to resources, services, and opportunities. abakaliki urban area, like many urban centers in nigeria, exhibits disparities in income, education, and access to basic services, which can affect the capacity of different groups to cope with and contribute to solutions for plastic waste management. by analyzing how plastic waste is generated, discarded, and perceived across various socioeconomic groups, this research will shed light on the potential disparities in environmental impacts and vulnerabilities among residents. furthermore, this study aims to contribute to the broader discourse on sustainable urban development and environmental justice by highlighting the need for inclusive and context-specific strategies to address plastic waste challenges. as abakaliki continues to grow and urbanize, finding innovative approaches to plastic waste management that consider the diverse needs and capacities of its residents is not only an environmental imperative but also a crucial step toward achieving a more equitable and sustainable urban future. 1.2 statement of the problem the rapid proliferation of plastic waste in urban areas of south east nigeria, including abakaliki, has raised significant environmental and socioeconomic concerns. while plastic waste management is essential for environmental sustainability, there is a notable absence of comprehensive research addressing the assessment of plastic waste and its potential for wealth generation in the abakaliki urban area. the lack of effective plastic lifecycle analysis management and environmental impact affect the wealth creation in abakaliki urban area, south east nigeria. the research aims to contribute to the development of a holistic and sustainable approach to managing plastic waste in abakaliki urban area, ultimately mitigating its adverse environmental impacts while harnessing its potential for economic prosperity. 1.3 objective of the study the main objective of this study is the assessment of plastic waste and wealth in abakaliki urban area, south east nigeria. the specific objective sought to; i. examine the effect of plastic lifecycle analysis on the wealth creation in abakaliki urban area, south east nigeria. ii. evaluate the effect of environmental impact on the wealth creation in abakaliki urban area, south east nigeria. 1.4 hypotheses of the study i. plastic lifecycle analysis has no significant effect on the wealth creation in abakaliki urban area, south east nigeria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ii. environmental impact has no significant effect on the wealth creation in abakaliki urban area, south east nigeria. review of related literature 2.1 concept review plastic waste the concept of plastic waste refers to the disposal or abandonment of plastic materials, products, or items that are no longer in use or have reached the end of their lifecycle. plastic waste has become a global environmental concern due to its widespread use, persistence in the environment, and detrimental effects on ecosystems and human health. understanding the concept of plastic waste involves considering its characteristics, sources, impacts, management, and potential solutions (mohamed 2016). the concept of plastic waste represents the environmental, social, and economic challenges associated with the widespread use and disposal of plastics. effective plastic waste management requires a multifaceted approach that involves reducing plastic consumption, improving waste management infrastructure, and promoting sustainable alternatives to plastics to mitigate its negative impacts on the planet (horodytska et. al, 2019). there are four basic things man needs to survive, air to breath, water to drink, food to eat and land to stand on. if plastic waste threatens these four basic needs, then a need for plastic waste management is necessary. the three solid waste management strategies are the 3r (reduce, reuse and recycling) (mohamed 2016, yosi et al 2019), also suggested landfill and incineration, however, one of the most efficient methods of managing plastic wastes is through recycling. although, plastic litter comes from developing countries, a small amount comes from western countries, primarily due to the limited capacity of collection systems and low recycling rates. however, horodytska et. al, (2019), stressed the need for recycling in order to minimize the amount of waste to be disposed to avoid waste from ending up in rivers, oceans and other environments. from the environmental and socioeconomic standpoints, the best answer to the problem of how to manage waste plastic is to recycle it (woldemar 2019). characteristics of plastic waste: 1. diversity of plastics: plastic waste comprises a wide range of synthetic polymers, each with varying properties, durability, and recyclability. common plastics include polyethylene (pe), polypropylene (pp), polyvinyl chloride (pvc), polyethylene terephthalate (pet), and polystyrene (ps). 2. persistence: plastics are highly durable and can persist in the environment for hundreds of years, slowly breaking down into smaller particles known as microplastics. 3. versatility: plastic waste encompasses various forms, including single-use items (e.g., plastic bags, bottles, straws), packaging materials, consumer goods, and industrial products. plastic lifecycle analysis (lca) plastic lifecycle analysis (lca), also known as life cycle assessment of plastics, is a comprehensive and systematic methodology used to evaluate the environmental impacts associated with the entire lifecycle of plastic products, from their production to their disposal or recycling (horodytska et. al, 2019). this analytical tool is crucial for understanding the environmental footprint of plastics and identifying opportunities for improvement in terms of sustainability and resource efficiency. the concept of plastic lifecycle analysis is instrumental in promoting sustainable plastic production and consumption (yosi et al 2019). it allows for a holistic understanding mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of the environmental consequences of plastics, which is essential in a world grappling with plastic pollution and climate change. by identifying opportunities for reducing environmental impacts and making informed decisions about the design, production, and disposal of plastic products, lca contributes to the development of more sustainable and environmentally friendly plastic materials and practices. it is a valuable tool for researchers, industries, and policymakers aiming to address the complex challenges associated with plastics (yosi et al 2019). figure 1. plastic life cycling process. the life pattern of plastic items has shown that the traditional straight model from birth to internment is an impractical interaction that brings about contamination. plastics, for all intents and purposes, do not biodegrade, so disposed-of waste amasses on the grounds and in the oceans, getting ingested by creatures and delivering harmful synthetics to the detriment of our living surroundings. this need not be the situation. there are elective pathways plastics can take to evade their ‘destiny’ as waste and poisons environmental impact the concept of environmental impact in the context of plastic waste refers to the wide-ranging and often adverse effects that plastic waste has on the natural environment, ecosystems, and human well-being. plastic waste, due to its persistence and widespread use, poses significant environmental challenges, and understanding its mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset environmental impact is crucial for mitigating its negative consequences. the environmental impact of plastic waste involves a multifaceted approach that includes reducing plastic consumption, improving waste management practices, promoting recycling and circular economy principles, and developing sustainable alternatives to conventional plastics. government regulations, public awareness campaigns, industry initiatives, and international cooperation are all essential components of mitigating the environmental impact of plastic waste and fostering a more sustainable relationship with plastics in our society. figure 2 impact of plastic waste on the environment. there is no denying that plastic is an ingenious material. composed of long chains of synthetic polymers, plastic is strong, light, and highly flexible. it can be manipulated into a multitude of forms, from drinking straws and bottles to car parts and diapers. since the 1907 invention of bakelite, the first synthetic plastic, the world has been plastics crazy. according to our world in data, over the past 65 years, annual production of plastics increased nearly 200-fold, to 381 million tonnes. unfortunately, it now turns out, the increasing use of this versatile substance has come at a high cost to the planet. data from the national oceanic and atmospheric administration (noaa) and woods hole sea grant shows that some plastic products can take up to 600 years to break down. landfills are overflowing, oceans are becoming choked, and wildlife is suffering. the world economic forum predicts that by 2050, oceans will contain more plastic, by weight, than fish. the ocean cleanup project has estimated that the great pacific garbage patch (gpgp), about 618,00 squaremile area of marine debris between hawaii and california, contains 1.8 trillion pieces of plastic. such statistics, along with distressing photographs of birds and mammals tangled-up in — and even consuming — plastic waste, have highlighted the magnitude of the problem. now, hashtags such as #plasticfree are trending on social media mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset as consumers, governments, and companies respond. data is not only being used to track the whereabouts and volume of plastic on our planet; it is supporting the drive to reduce our dependence on it. wealth creation the concept of wealth creation in the area of plastic waste revolves around harnessing the economic potential of plastic waste management and recycling initiatives. while plastic waste is often viewed as an environmental problem, it also presents opportunities for generating wealth, creating jobs, and contributing to sustainable development. the concept of wealth creation in the area of plastic waste signifies the transformation of a perceived environmental challenge into an economic opportunity. by adopting sustainable practices, promoting recycling, and fostering innovation, societies and economies can not only address plastic waste issues but also generate wealth, create jobs, and contribute to a more sustainable and circular approach to plastic use and management. here are key aspects of the concept of wealth creation in the context of plastic waste: 1. recycling and circular economy: • recycling plastic waste allows for the recovery of valuable materials. this can include the collection and processing of plastic bottles, containers, and packaging for reusing them in the production of new plastic products. • a circular economy approach promotes continuous recycling and upcycling of plastic materials, reducing the need for virgin plastic production and conserving resources. 2. resource recovery: • plastic waste contains valuable resources, such as polymers, which can be extracted and used to manufacture a wide range of products, including textiles, building materials, and more. • the recovery of valuable materials from plastic waste contributes to resource conservation and reduces the environmental impact of raw material extraction. 3. job creation: • the plastic recycling industry can generate employment opportunities at various levels, from collection and sorting to processing and manufacturing. • job creation in plastic waste management can particularly benefit local communities and economies. 4. entrepreneurship and innovation: • the recycling and repurposing of plastic waste offer fertile ground for entrepreneurial ventures and innovation. entrepreneurs can develop new technologies, processes, and business models to address plastic waste challenges. • innovation can lead to the creation of new products and services, further contributing to economic growth. 5. waste-to-energy: • some regions invest in waste-to-energy facilities that use plastic waste as a source of energy. this can contribute to energy production, reducing the demand for fossil fuels. • energy generation from plastic waste can also lead to revenue generation for municipalities or waste management companies. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.2 theoretical review the theoretical framework for this study emanated from different models in geographical studies. the diffusion model by haggerstrand (1967) and nearest neighbour analysis by evans and clark (1954) were employed in this study. it is the hierarchical diffusion which describes transmission through a regular sequence or order of lease. this process is typified by the diffusion of innovations. for example, new methods of waste management trickle down from advanced societies to less developed societies. the developed countries have efficient waste management policies, which are gradually being adapted, in other countries of the world (expansion diffusion). with the present technological advancement and the trend towards globalization, waste management has improved over time. the diffusion model could be applied to a non-linear function as “s-shaped” curve that characterized any diffusion process. this could be represented with the equation shown as; where: p = proportion of people accepting a new innovation t = the time, the process of innovation diffusion started, the two variables are linked by three parameters. u = the upper limit a = which determines the values of p, when t is zero. b = a mathematical constant with a value 2.7183 the conceptual factor, which affects the operations of the psp scheme mostly, is the distance factor to landfill sites. its location will determine trip frequency time of haulage and invariably cost of transportation of the waste. having realized this factor, government had decentralized the location of landfill sites. as at present, there are three landfill sites and psp operators well encouraged to make use of the nearest landfill sites, so as to reduce time and cost and consequently, enhance efficiency. the mode of operation is in line with the distance decay concept, which according to ayeni (2000), was based on a straight-line measurement of distance separating a phenomenon and the nearest neighbour space. adetokunbo and herbert (2003) submitted that management of waste is a key element in the protection of public health, because failure to manage waste properly exposes people to increased risk of infectious diseases. waste management is the selection and application of suitable techniques, technologies and management programmes to achieve specific waste management objectives and goals. waste management for non-hazardous residential and institutional waste in metropolitan areas are usually the responsibility of local government authorities, while hazardous commercial and industrial waste is usually the responsibility of the waste generator. according to ogunleye and ibitoye (2006), improper disposal of solid waste constitutes ‘serious threat to human health and to the achievement of sound environmental sanitation’. igbanugo (1986) submitted that refuse dumpsites are converted to urinal and defection sites by destitutes, invaded by scavengers and animals, and served as breeding ground for disease vectors (flies, rodents, etc). also, accumulated garbage and rubbish become eye sore in the community, and pollute the air, and act as breeding grounds for mosquitoes and other harmful insects; they also encourage street folding. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. methodology this is a quantitative study conducted in the urban area of abakiliki south east nigeria, by collecting empirical data from selected sample. positivism pattern believes in an inferential approach where researchers agree on previous investigated studies and further investigate by collecting empirical data in a different context. more precisely, researchers agree with previous theory and conduct the study to prove it whether true or false. this study is following a quantitative method to test four hypotheses proposed in relation to the assessment of plastic waste and wealth in abakiliki urban south east nigeria. the sample for this study is a relatively large group of people in residing within these urban areas. simple random sampling technique applied to get a response from the selected population that every respondent has an equal opportunity being selected. this study collected 362 questionnaires to investigate assessment of plastic waste and wealth in abakiliki urban south east nigeria. to test the hypotheses, 344 data utilized after data screening and structural equation modelling applied for the analysis and questionnaire distributed by the researchers directly. measures the plastic waste and environment impact was measured by developing a measurement item that agrees with each of the variables. the outcome variable is wealth creation. all items were scored with a five-point likert scale, ranging from (1) strongly disagree to (5) strongly agree. this construct reflects assessment of plastic waste and wealth in abakiliki urban south east nigeria. 4. data analyses and hypotheses results table 1 shows the demographic distribution of the respondents for gender, marital status, age, education level and working experience in the industry. the study was analysed using the structural equation modeling technique with the aid of smartpls 4.0. table 1: demographic profile of the respondents (n = 344) characteristics frequency percentage gender male female 187 157 54 46 marital status single married 145 199 42 58 age(years) 20 -29 yrs. 30-39 yrs. 40-49 yrs. 50-59 yrs. 60 yrs. 90 105 58 77 14 26 31 17 22 4 academic qualification b.sc/hnd masters phd others 189 102 17 36 55 30 5 10 experience 1-5 135 39 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 6-10 11-14 15 and above 94 61 54 27 18 16 as shown in table 1, for gender, 54% of the respondents are male, and 46% are female. majority of the respondents are married, which is 58% and single are 42%. in terms of age group, highest age group consists of "30 to 39years" which is 31% followed by "20 to 29 years" which is 26%, "50 to 59 years" 22%, "40 to 49 years" 17% and 60 years and above is 4%. for academic qualification, majority of the respondents are bachelor and master's degree holder, which are 55% and 30% respectively, while phd and others recorded the least response with 5% and10% respectively. while looking into the job experience of the respondents, most of them have experiences of 1 to 5 years, followed by 6 to 10 years is 27%, 11-14 years is 11% and more than 15 years is 16%. study results the researchers examined the data using pls-sem to examine the assessment of plastic waste and wealth in abakiliki urban south east nigeria. we report results using a level of significance at p<.01 and p<.001. table 2: construct validity and reliability in developing the study variable, several important measures were followed to constructs validity and reliability and content validity. for content validity, different operational was evaluated by studying the existing literature and measurement used that contains multiples items. both the confirmatory and exploratory analysis confirm the factorability of the variables. figure 1 represents the factor loading of individual items. only few items show the loading above 0.40, and the remaining items in the model exceeded the suggested loading of 0.70. all the constructs are shown in table 2 that none of the variable cronbach alpha less than 0.70. furthermore, composite reliability was above the accepted level. to ensure the convergent validity, the average variance extracted also checked and showed all variable exceeded the recommended value of 0. so, all the variables confirm content validity and reliability. cronbach's alpha rho_a composite reliability average variance extracted (ave) wealth creation 0.861 0.868 0.906 0.706 plastics lifecycle analysis 0.840 0.862 0.876 0.505 environmental impact 0.790 0.819 0.862 0.610 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 3: factor loadings of the construct pla eni wc comments pla1 0.693 >.40 pla2 0.601 >.40 pla3 0.743 >.40 pla4 0.653 >.40 pla5 0.800 >.40 pla6 0.714 >.40 pla7 0.754 >.40 eni1 0.840 >.40 eni2 0.762 >.40 eni3 0.774 >.40 eni4 0.774 >.40 wc1 0.836 >.40 wc2 0.817 >.40 wc3 0.897 >.40 wc4 0.808 >.40 table 3 shows the factor loading of individual items which is above >.40 threshold and confirms the confirmatory factor analysis. to evaluate the discriminant validity of the 4-variables is used in the study, heterotrait-and monotrait (htmt) analysis was executed. table 4: discriminant validity (htmt) wealth creation plastic lifestyle analysis environmental impact wealth creation plastic lifestyle analysis 0.587 environmental impact 0.580 0.813 result of confirmatory factor analysis shown in table 4 supports the empirical evidence of the uniqueness of most of the variables. it is pertinent to state that the values in bold in the above table indicated discriminant validity problems according to htmt0.85 criterion. this implies that the htmt criterion detects collinearity problem among latent construct. however, all the variable is ensured of the discriminant validity for further analysis by maintaining that no correlation exceeds the limit of htmt. structural equation modelling in smart-pls, to observe the effects of independent variables on the dependent variable, normally two steps followed are measurement model and structural model. some of the criterions, such as construct validity and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset reliability already discussed above. in addition to that in the structural modelling equation r square also shown for the predictive ability of independent variables on the dependent variables. the value of r2 (0.591) indicates that the 59.1% of the variation in wealth creation is caused by the two independent selected variables. additionally, for the model fit srmr value was examined, which is 0.038 means model is a good fit table 5: the direct effect of plastic lifecycle analysis and environmental impact on the wealth creation of abakiliki urban southeast nigeria original sample (o) sample mean (m) standard deviation (stdev) t statistics (|o/stdev|) p values plastic lifecycle analysis -> wealth creation 0.218 0.222 0.049 4.490 0.000 environmental impacts -> wealth creation 0.240 0.231 0.058 4.159 0.000 in structural modelling, the total of four hypotheses was examined through the use of empirical data collected from the individual living within the urban area of abakiliki south east, nigeria. all the two hypotheses were accepted. for a better presentation, table 5 shows the p-value and t-value. there is a clear evidence that we will accept all the hypothesis presented in this study such that plastic lifecycle analysis and environmental impact are statistically significant and have a positive effect on the wealth creation in abakiliki urban south east, nigeria. summary of the test of hypothesis hypothesis one h0: plastic lifestyle analysis has no significant effect on wealth creation in abakiliki urban southeast nigeria h1: plastic lifestyle analysis has a significant effect on wealth creation in abakiliki urban southeast nigeria conclusion table 5 above suggest that plastic lifestyle analysis is statistically significant and have a positive effect on wealth creation given that β=0.218 and p <0.001. we therefore conclude that a unit change in plastic lifecycle analysis will cause a corresponding unit increase in wealth creation in abakiliki urban southeast nigeria. hypothesis two h0: environmental impact has no significant effect on wealth creation in abakiliki urban southeast nigeria. h1: environmental impact has a significant effect on wealth creation in abakiliki urban southeast nigeria. conclusion table 5 above suggest that environmental impact is statistically significant and have a positive effect on wealth creation given that β=0.240 and p <0.001. we therefore conclude that a unit change in environmental impact will cause a unit increase in wealth creation in abakiliki urban southeast nigeria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset conclusion in conclusion, the assessment reveals a complex yet hopeful landscape in the interplay between plastic waste and wealth in abakaliki urban area. while challenges persist, the study emphasizes the potential for positive change through strategic interventions, community involvement, and the cultivation of a circular economy mindset. by integrating the recommendations outlined in this research, abakaliki has the opportunity to not only address its plastic waste management challenges but also to create a thriving, sustainable, and economically prosperous urban environment for current and future generations. the plastic lifecycle analysis and environmental impact are statistically significant and have a positive effect on the wealth creation in abakiliki urban south east, nigeria. we therefore, concluded that the assessment of plastic waste has significance positive effect on the wealth in abakaliki urban area, south east nigeria. recommendation the analysis underscores the correlation between sustainable plastic practices and enhanced wealth creation, shedding light on several key areas that businesses and individuals can leverage for financial gain. here are some key recommendations based on the study: i. the government should identify and invest in companies that are actively adopting sustainable and eco-friendly plastic alternatives. with the growing global focus on environmental responsibility, businesses in this sector are likely to experience increased demand, leading to potential returns for investors. ii. the government should encourage and invest in research and development initiatives focused on green technologies. the development of innovative solutions for sustainable agriculture, waste management, and clean energy can present lucrative opportunities for patents, creating a competitive advantage in the market. reference adetokunbo o. l and herbert m.g (2003): solid waste disposal. short textbook of public health medicine for the tropics. 4th ed. kinson press lagos. ayeni, b. (2000): quantitative methods for geography students, ibadan, research support services. haggerstrand, t. (1967): on the onte carlo simulation diffusion. garrison and marble, cited in olatunji, a.j. (2006) on the introduction to theoretical geography. akure, b.j productions. horodytska, o; cabanes, a and fullana, a. (2019) plastic waste management: current status and weaknesses. the handbook of environmental chemistry, springer, berlin, heidelberg, 2019 life cycle assessment for a plastic and a glass product. available online:https://life cycle of plastic. word press.com (accessed on 17 april 2021). mohamed el-newehy, (2016), plastic waste management, king saud university petrochemical research chair, department of chemistry, college of science, riyadh 11451, saudi arabia,. http://fac.ksu.edu.sa/melnewehy. mailto:topacademicjournals@gmail.com http://fac.ksu.edu.sa/melnewehy academic journal of science, engineering and technology vol. 08, issue 4; july -august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ogunleye o.s. and ibitoye, o.a. (2006): the pattern of vehicular traffic flow in ado-ekiti, nigeria. international journal of social and policy issues, vol 3, number 2, pp. 69-75. woldemar ambrieres,(2019) plastics recycling worldwide: current overview and desirable changes », field actions science reports. yosi agustina hidayat, saskia kiranamahsa, muchammad arya zamal, (2019). a study of plastic waste management effectiveness in indonesia industries, aims energy 7 (3) 350–370. life cycle assessment for a plastic and a glass product. available online: https://lifecycleofplastic.wordpress.com (accessed on 17 april 2021). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset environmental impact of mining in southwest burkina faso: a comprehensive analysis marie-claire diarra école nationale supérieure université ouagadougou canada abstract: the intensification of mining activities in burkina faso, driven by increased global demand for minerals and metals, particularly gold, has raised significant economic prospects for the nation. this transformation from a traditionally agrarian economy to a burgeoning mining hub has positioned burkina faso among the leading gold-producing countries in africa. this transition is marked by the operation of seven active gold mines within the country, ushering in newfound opportunities and challenges. one notable player in this landscape is the poura gold mine, historically the pioneer industrial gold mine in burkina faso. this mine, managed by the state-owned mining company soremib from 1985 to 1999, played a pivotal role in shaping the country's mining sector. during its operational years, poura gold mine contributed significantly, yielding approximately 15 tons of gold. in 2012, an american mining company, newmont, reopened the poura gold mine, primarily focusing on exploration and prospection activities. however, the remnants of the earlier mining era (1985-1999) still linger, manifesting as substantial volumes of mine wastes accumulated at the site. this study delves into the evolving dynamics of burkina faso's mining landscape, with a particular focus on the poura gold mine's historical significance and its implications for the present and future of mining in the region. it explores the environmental and socioeconomic ramifications of mining activities in burkina faso, shedding light on the challenges and opportunities that come with this transition. keywords: burkina faso, mining, poura gold mine, gold production, environmental impact. introduction due to the high mineral and metal demand of emerging economies such as india and china, the prices of these commodities have increased on the international market, leading to intensive mining worldwide. burkina faso, a landlocked country, has been long considered as a least developed backward agricultural country that may benefit from the "mining boom". since 2010, the country has become the fourth largest african gold producing country after south africa, ghana and mali. nowadays burkina faso has seven active gold mines (taparko, essakane, mana, youga, inata, kalsaka, sabcé). the poura gold mine (figure 1) was the first industrial gold mine of the country. the mine was operated from 1985 to 1999 by the state owned mining company "société de recherches minières du burkina faso (soremib)". during this period, poura gold mine produced approximately 15 tons of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gold. in 2012 the mine was reopened by newmont, an american mining company, but the activities are currently limited to exploration and prospection. the previous mining (i.e., 1985-1999) has generated several tons of mine wastes which are still piled up on the site. these mine wastes consist of overburden, waste rock dumps, tailings and usually various sulfide and iron minerals. in the nature the interaction between these minerals and oxygen and/or water lead to their oxidation, a process known as acid rock drainage (ard). however, an exacerbated ard through mining is known as acid mine drainage (amd). amd is characterized (kawatra and natarajan, 2001) by high acidity (low ph) and high concentrations of sulfate and metals and metalloids such as iron (fe), manganese (mn), aluminum (al), zinc (zn), copper (cu), nickel (ni), lead (pb), cadmium (cd) and arsenic (as). as a result, amd represents, by far, the most serious threat to the ecosystem adjacent to mining sites. thus, amd acidifies the receiving environment through a release of sulfuric acid, and also maintains in solution highly reactive and toxic metals (us-epa, 2000; naicher 2003; galvez-cloutier and lefrancois 2005). thus, amd enhances the mobility and bioavailability of potentially toxic metals in the ecosystem. the main metals released into the environment due to mining are: fe, mn, pb, zn, cd, cr and ni. increased solubilization of these metals following amd generation can enter food web, and pose serious threats to human health through consumption, for example, of contaminated seafood. in humans, the metals are stored in most soft tissues, particularly the liver and kidneys as well as in the bone, collon (2003). the ingested metals are therefore bioaccumulative and non-biodegradable in human body, and thus highly toxic even at very low doses (trace amounts). the aim of this paper is to assess the spread of potentially harmful elements (phe), e.g. heavy metals associated to mine wastes and tailings, and its impacts on the environment. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: geological map of burkina faso with the location of poura gold mine. acid mine drainage (amd) by definition, acid mine drainage is an effluent produced during mining or after the mine closure which physic-chemical characteristics differ from the original water (collon, 2003). in the deposits and in particular metalliferous deposits, minerals are usually associated with sulfur or iron minerals (pyrite, chalcopyrite, arsenopyrite, galena, sphalerite, pyrrothite, covelite). consequently, these sulfide minerals are found in tailings or waste rock piles. exposure of tailings to air and water leads to sulfate and iron oxidation and production of acid mine drainage known as amd. the kinetics of this oxidation reaction is enhanced in the presence of thiobacillus ferrooxidan bacteria, that can speed up the reaction rate about 105 time compared to abiotic reaction. the acidification will impact the release of metals from various minerals. an orange-brown color of insoluble fe (oh)3 usually characterizes this acidic drainage. assuming the presence of pyrite in tailings (kleinman et al., 1981; aubertin et al., 2002a; bussière et al., 2005), interaction between tailing seeping or highly acidic process waters and a receiving environment (e.g., surface water) with a ph close to neutral (5<ph<7), oxygen will directly oxidize pyrite as illustrated in reaction 1. fes2 + 7/2o2 + h2o → fe2+ + 2so4 2+ 2h+ [1] mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ferrous iron, released from the oxidation of pyrites, can be oxidized to ferric iron according to the following reaction: fe2+ + 1/4o2 + h+ → fe3+ + 1/2h2o [2] at relatively high ph (ph> 4), the ferric iron precipitates as ferric hydroxide releasing more acid in water (reaction 3). fe3+ + 3h2o → fe(oh)3 + 3h+ [3] the ferrous iron can also be precipitated as iron hydroxide and produce acid as shown in reaction 4. fe2+ +1/4o2 + 3/2h2o → feooh + 2h+ [4] when the ph is sufficiently low (ph <4), ferric iron remains in solution, and thus playing the role of a highly reactive oxidant (the so-called indirect reaction). the indirect oxidation of pyrite produces more protons, and thus exacerbates acidification of the receiving environment (reaction 5). fes2 + 14fe3+ + 8h2o → 15fe2+ + 2so42+ 16h+ [5] the overall pyrite oxidation reaction can be expressed as follows: fes2 +15/4o2 + 7/2h2o → fe (oh)3 + 2h2so4 [6] these equations show that the oxidation of one mole of pyrite produces two moles of sulfuric acid in the environment. methodology samples of surface water, groundwater (hand-pumped boreholes and wells), soil and mine wastes were collected at poura old gold mine.water concerned surface water and groundwater to assess their chemical parameters. the ph and water temperature have been measured in the field; geographic coordinates of sampling site have been recorded. for ground water, the depth (of the well) is recorded. each sample of mine wastes and soil is a composite of three sub-samples collected from sampling sites located at the distance of 10-20 m from each other. about, 3 kg have been dried, sieved and homogenized. the < 2mm fraction (about 5g), have been taken for analysis. all samples (water, mine wastes, and soil) were shipped to johannesburg (south africa) to the laboratory "acmelabs" for analysis. water samples have been the subject of the determination of f, ph, conductivity, alkalinity and hg. samples of mine waste, and soil were subjected to aqua regia digestion and a full suite of 36 elements have been analyzed. results sampling all collected samples are reported in figure 2. a total of 10 groundwater samples, 14 of surface water, 16 of soil and 11 of mine wastes were collected. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2: location of sampling sites on the satellite map (google imaging © 2014) groundwater and surface water results of chemical analyses of the groundwater and surface water are given in tables 1a and 1b. table 1a: chemical analyses of groundwater physical parameters miscellaneous inorganics (mg/l) sample depth (m) temperature conductivity (°c) (µs/cm) ph fluoride alkalinity bicarbonate carbonate total hco3 co3 caco3 hydroxide oh gw1 *hpb 31.50 340 8.45 0.190 189 221 4.82 <0.50 gw2 *hpb 32.30 239 8.35 0.120 133 158 2.22 <0.50 gw3 25 23.40 157 8.02 0.096 78.6 95.9 <0.50 <0.50 gw4 *hpb 30.70 357 8.39 0.250 197 232 4.03 <0.50 gw5 30 28.60 169 7.73 0.098 58.9 71.9 <0.50 <0.50 gw6 *hpb 30.80 365 8.37 0.240 155 184 2.87 <0.50 gw7 *hpb 30.80 339 8.38 0.200 145 170 3.04 <0.50 gw8 *hpb 31.00 455 8.32 0.063 193 230 2.42 <0.50 gw9 10 29.40 153 7.49 0.045 17.8 21.7 <0.50 <0.50 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gw10 *hpb 28.40 456 8.67 0.130 244 271 13.10 <0.50 *hpb: hand-pumped borehole table 1b: chemical analyses of surface water physical parameters miscellaneous inorganics (mg/l) sample temperature (°c) conductivity (µs/cm) ph fluoride alkalinity total caco3 bicarbonate hco3 carbonate co3 hydroxide oh sw1 28.3 234 8.03 0.076 60.70 74.10 <0.50 <0.50 sw2 29.1 233 7.88 0.065 61.80 75.40 <0.50 <0.50 sw3 29.0 454 8.33 0.380 165 197 2.12 <0.50 sw4 27.6 60.4 6.61 0.064 8.29 10.10 <0.50 <0.50 sw5 34.2 146 8.07 0.110 70.00 85.40 <0.50 <0.50 sw6 28.3 45.6 7.44 0.058 16.30 19.80 <0.50 <0.50 sw7 32.2 45.7 7.54 0.072 16.70 20.30 <0.50 <0.50 sw8 29.3 225 7.95 0.059 59.50 72.60 <0.50 <0.50 sw9 28.6 287 8.13 0.670 150 183 <0.50 <0.50 sw10 27.9 624 8.51 0.400 290 336 8.99 <0.50 sw11 30.2 112 8.06 0.090 47.10 57.50 <0.50 <0.50 sw12 27.9 556 8.27 0.160 191 233 <0.50 <0.50 sw13 34.2 8810 2.23 0.027 <0.50 <0.50 <0.50 <0.50 sw14 32.2 48.0 7.23 0.076 15.50 18.90 <0.50 <0.50 mine wastes and soil the contents of some potentially harmful elements are shown in table 2a and 2b. this table shows for arsenic, copper, nickel, lead and zinc relatively much higher contents in the mine wastes than in soils. concentrations in mine wastes are: arsenic (4 to more than 10000 ppm), lead (2 to 1339.6 ppm), zinc (14 to 604 ppm), copper (7 to 534.8 ppm), cobalt (3 to 40 ppm), chromium (5 to 304 ppm), nickel (3 to 101.3) and cadmium (0.1 to 5 ppm). these contents in the soil are: arsenic (0.5 to 335.2 ppm), lead (3.8 to 49 ppm), zinc (7 to 130 ppm), copper (7 to 49.7 ppm), cobalt (4 to 35.8 ppm), and chromium (41 to 299 ppm), nickel (6 to 133.6 ppm) and cadmium (for the most less than the detection limit). table 2a: contents of some potentially harmful elements in the mine waste samples element as cd co cr cu pb zn ni hg fe unit ppm ppm ppm ppm ppm ppm ppm ppm ppm % *lod 0.5 0.1 0.1 1 0.1 0.1 1 0.1 0.01 0.01 w1 198.6 <0.1 3.4 5 7.7 21.9 21 5.8 0.24 0.70 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset w2 4.2 <0.1 39.0 87 80.9 2.3 84 68.3 <0.01 7.23 w3 563.7 0.1 35.6 39 41.6 11.9 69 47.4 0.05 3.37 w4 44.0 <0.1 4.7 14 17.8 1.3 14 3.2 <0.01 1.50 w5 4025.5 5.2 38.1 70 534.8 948.0 588 75.0 2.25 5.12 w6 549.8 <0.1 6.3 18 11.4 10.9 24 10.9 0.04 1.92 w7 151.5 <0.1 38.5 64 44.3 4.9 42 33.8 0.09 3.75 w8 141.8 <0.1 19.7 10 26.6 2.6 23 13.8 0.06 1.84 w9 309.6 1.7 28.7 304 253.8 804.0 604 101.3 0.26 12.88 w10 >10000.0 0.9 24.4 15 251.3 1339.6 107 60.2 4.08 9.24 w11 >10000.0 2.8 40.0 24 329.1 1069.8 364 83.3 3.68 10.97 *lod: li mit of detectio n table 2b: contents of some potentially harmful elements in the soil sampl es element as cd co cr cu pb zn ni hg fe unit ppm ppm ppm ppm ppm ppm ppm ppm ppm % *lod 0.5 0.1 0.1 1 0.1 0.1 1 0.1 0.01 s1 1.3 <0.1 16.3 52 23.7 11.8 28 24.4 2.92 s2 335.2 0.2 35.8 51 49.7 49.0 130 28.7 1.04 4.36 s3 9.9 <0.1 16.2 83 29.0 4.4 20 36.6 <0.01 3.37 s4 7.3 <0.1 25.8 141 27.1 5.6 34 74.6 0.01 3.86 s5 0.5 <0.1 4.8 25 7.6 6.8 7 6.6 <0.01 1.37 s6 3.6 <0.1 16.8 67 17.7 4.6 16 36.8 <0.01 2.23 s7 20.8 <0.1 17.9 55 19.0 4.9 11 11.7 0.02 2.38 s8 11.5 <0.1 22.0 299 23.8 3.8 21 133.6 0.01 3.63 s9 64.2 <0.1 24.6 70 31.5 16.2 73 21.4 0.84 4.16 s10 33.9 <0.1 20.3 50 23.9 4.6 35 25.2 0.05 3.52 s11 105.6 <0.1 30.7 283 42.0 30.2 47 22.5 1.18 12.89 s12 4.5 <0.1 16.6 103 18.1 4.8 17 30.8 <0.01 2.55 s13 19.0 <0.1 18.5 41 18.9 4.9 12 14.8 <0.01 2.17 s14 5.2 <0.1 14.1 57 11.6 5.6 15 12.1 0.02 2.92 s15 4.5 <0.1 12.2 43 14.3 4.1 13 16.7 <0.01 2.67 snc1 17.7 <0.1 20.0 70 15.7 5.9 13 15.2 <0.01 2.43 *lod: limit of detection discussion all samples were collected in august (rainy season), which justifies the relatively high temperatures of water samples. ground water is characterized by a ph close to neutrality (7.49-8.67) and relatively low conductivity values compared to the surface water (153-456 µs/cm). the surface water samples sw4 and sw13 show lower values of ph which are respectively 6.61 and 2.23. sample sw13 with high conductivity (8810 us / cm) and high acidity (low ph) confirms the presence of amd resulting from the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset oxidation of tailings stored there. these values indicate that oxidation is local and very advanced in that the ph value is below the minimum 6.5 required for the protection of aquatic life and even below the acute toxicity of 5.0 (berryman et al. 2003). according to the standards in force in burkina faso guideline values for fluoride are 0.07 to 1.5 mg/l. concentrations of fluoride are higher in groundwater than in surface water. however, these values are consistent with the guideline values. the alkalinity values are highly variable from one sample to another, and are higher in groundwater than in surface water. the acidification of sw13 is confirmed by its alkalinity which is less than the detection limit (0.50 mg /l caco3). according to the "ministère du développement durable, de l’environnement, de la faune et des parcs" (mddefp, 2013) the sensitivity of a medium to the acidification varies with alkalinity: high sensitivity, alkalinity < 10 mg /l caco3; mean sensitivity, alkalinity ranges from 10 to 20 mg /l caco3; low sensitivity alkalinity > 20 mg /l caco3. the anions hco3 -, co3 2and ohhave also been analyzed. bicarbonate, carbonate and hydroxide form alkalinity, however, natural waters usually contain no carbonate or hydroxide. the results given in tables 2a and 2b show that the concentrations of various analyzed elements are higher in mine tailings than in soils. this is due to the mineralogy of the host rocks of the mineralization. indeed, at poura geology comprise mainly volcanic rocks (andesite-dacite), volcanosedimentary (tuffs, agglomerates) and detrital sedimentary rocks (pelitic to conglomerate rocks) which are intruded by mafic to felsic intrusions (granites gabbroic). gold is associated with quartz veins whose cracks are filled by sulfides: pyrite (fes), arsenopyrite (feass), sphalerite (zns), galena (pbs), chalcopyrite (cufes). high levels in some soil samples (arsenic: s2, s11; lead: s2 and zinc: s2) would come from contamination through leaching, solubilization (due to the decline in ph) and migration of elements from tailings stockpiles. this means enrichment for these elements. sampling site s2 is the most contaminated and mainly by arsenic, lead and zinc. for soils there are no guideline values from burkina faso. but according to canadian soil quality guidelines for the protection of environmental and human health (canada, atsdr, 2005), and taking into account the fact that these soils used for agriculture, some sites are polluted by arsenic, chromium, copper, lead, nickel and zinc. to assess the level of contamination, the index of geo-accumulation (igeo), (muller, 1969; krzysztof et al, 2003) was calculated for soil samples and mine wastes, to assess the presence and levels of contamination (table 3a, 3b). igeo cm = concentration of a given element in the tested soil; bv = concentration of the element in the earth’s crust (background value); the background values after levinson (1974) after lar et al. (2003). 1.5 = a constant accounting for fluctuations in the content of a given substance in the environment. the negative of geo-accumulation indexes for some elements indicates the absence of contamination. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the use of the index of geo-accumulation is based on seven descriptive classes for increasing igeo values shown in table 4. table 3a: igeo values for some elements in the soil element igeo as co cr cu pb zn ni s1 -0.24 1.04 0.84 1.20 0.90 -0.03 0.51 s2 2.17 1.38 0.83 1.52 1.51 0.04 0.58 s3 0.64 1.03 1.04 1.29 0.47 -0.18 0.69 s4 0.51 1.24 1.27 1.26 0.57 0.05 1.00 s5 -0.65 0.51 0.52 0.70 0.66 -0.63 -0.06 s6 0.20 1.05 0.95 1.07 0.49 -0.27 0.69 s7 0.97 1.08 0.87 1.10 0.51 -0.44 0.19 s8 0.71 1.17 1.60 1.20 0.40 -0.15 1.25 s9 1.46 1.21 0.97 1.32 1.03 0.39 0.46 s10 1.18 1.13 0.82 1.20 0.49 0.07 0.53 s11 1.67 1.31 1.58 1.45 1.30 0.19 0.48 s12 0.30 1.04 1.14 1.08 0.51 -0.25 0.61 s13 0.93 1.09 0.74 1.10 0.51 -0.40 0.30 s14 0.36 0.97 0.88 0.89 0.57 -0.30 0.21 s15 0.30 0.91 0.76 0.98 0.44 -0.36 0.35 snc1 0.90 1.12 0.97 1.02 0.59 -0.36 0.31 table 3b: igeo v alues for some elements in th e mine wastes element as igeo co cr cu pb zn ni w1 1.95 0.36 -0.18 0.71 1.16 -0.15 -0.11 w2 0.27 1.41 1.06 1.73 0.19 0.45 0.96 w3 2.40 1.38 0.72 1.44 0.90 0.36 0.80 w4 1.29 0.50 0.27 1.07 -0.06 -0.33 -0.37 w5 3.25 1.40 0.97 2.55 2.80 1.29 1.00 w6 2.39 0.62 0.38 0.88 0.86 -0.10 0.16 w7 1.83 1.41 0.93 1.47 0.51 0.15 0.65 w8 1.80 1.12 0.12 1.25 0.24 -0.12 0.26 w9 2.14 1.28 1.61 2.23 2.73 1.30 1.13 w10 >3.65 1.21 0.30 2.22 2.95 0.55 0.90 w11 >3.65 1.43 0.51 2.34 2.85 1.08 -0.11 table 4: igeo classes with ct to soil quality mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset res pe igeo value igeo class designation of soil quality > 5 6 extremely contaminated 4-5 5 strongly to extremely contaminated 3-4 4 strongly contaminated 2-3 3 moderately to strongly contaminated 1-2 2 moderately contaminated 0-1 1 uncontaminated to moderately contaminated 0 0 uncontaminated according to these classes, soils are uncontaminated to moderately contaminated (class 1) by arsenic, cobalt, chromium, copper, lead, zinc and nickel. they are moderately contaminated (class 2) by arsenic, cobalt, chromium, copper, lead and nickel. the igeo class 3, i.e. moderately to strongly contaminated sites concerns only arsenic. concerning mine wastes, igeo classes 1 and 2, i.e. respectively uncontaminated to moderately contaminated and moderately contaminated concern both element in table 4 (arsenic, cobalt, chromium, copper, lead, zinc and nickel). the highest degrees of contamination are caused by arsenic, copper and lead (class 3: moderately to strongly contaminated sites) and by arsenic (class 4: strongly contaminated sites). so, in soils and mine wastes, the most harmful element is arsenic. arsenic, copper and lead are the main constituents of sulfides (arsenopyrite: feass, chalcopyrite: cufes, galena: pbs) encountered in the mineralized host rocks at poura. this explains their high concentrations in mine wastes that resulted from the ore treatment or waste rocks. according to smedley et al (2007), the source of arsenic in burkina faso, is likely to be the oxidized sulfide minerals and secondary iron oxides in the mineralized zones. for these authors, high-as groundwater observed derive from zones of gold mineralization in birimian (lower proterozoic) volcano-sedimentary rocks, the gold occurring in vein structures along with quartz and altered sulfide minerals (pyrite, chalcopyrite, arsenopyrite). this is consistent with the assumption mentioned above. therefore, the high arsenic concentrations in soils and groundwater would be the host rocks of gold mineralization. at poura, soil contamination in arsenic would come from mine wastes stockpiles stored for many years. indeed, in the problems of environmental pollution, the main parameters to consider are the source, intensity, extent and vulnerability. if the source (oxidation of mine waste or amd), the intensity (igeo and igeo classes) and extent (contaminated sites) can be established, it is not the same the vulnerability without analyzes e.g. of plants, crops, blood, urine or hair. so, concerning vulnerability, despite the lack of analysis of plants and crops, heavy metals released into the environment through the oxidation of mine wastes can be absorbed by plants. indeed, several studies mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset e.g. álvarez et al (2003), huang (2007), zhang et al (2009), lar et al (2013), park and choi (2013), kalagbor and diri (2014) have shown that plants can absorb heavy metals that will be eventually encountered in their fruits, leaves and tubers. in addition, heavy metals and potentially harmful element released by the oxidation of mine wastes can be transported in the mouhoun river which is the main river in the region. the populations will be contaminated as a result in the consumption of fishes that have ingested these different toxic elements. conclusions this study shows that mine wastes stockpiles at poura, are oxidized in some places, due to their exposure during several years to water and atmospheric agents. this oxidation is the source of acidic ph of surface water or acidic effluents known as acid mine drainage (amd). this acid mine drainage results in the solubilization of potentially harmful elements (arsenic, cobalt, chromium, copper, lead, zinc and nickel) that are subsequently released into the environment. the index of geo-accumulation (igeo) and the descriptive classes for increasing igeo values indicate that arsenic, copper and lead are the most harmful elements. the soil is moderately contaminated (class 2) by arsenic, cobalt, chromium, copper, lead and nickel, then moderately to strongly contaminated (class 3) by arsenic. for mine wastes, moderately contaminated sites (class 2) are due to arsenic, cobalt, chromium, copper, lead, zinc and nickel; moderately to strongly contaminated (class 3) by arsenic copper and lead; strongly contaminated (class 4) by arsenic which appears to be the most polluting element. the source of these elements that cause the phenomenon of contamination would be sulfides and other metallic minerals which constitute the host rocks of the mineralization and are encountered in mine wastes. references álvarez, e. et al. (2003). heavy metals in the dump of an abandoned mine in galicia (nw spain) and in the spontaneously occurring vegetation. the science of the total environment 313, 185-197. atsdr (2005). toxguide for arsenic, u.s. department of health and human service. canadian environmental council of ministers of the environment (1999): soil quality guidelines for the protection of environmental and human health, updated 2006. aubertin, m., bussière, b., et bernier l. (2002a). environnement et gestion des rejets miniers, manuel sur cédérom. berryman, d., et al. (2003). l’impact d’anciens parcs à résidus miniers sur la qualité de l’eau et les communautés benthiques de la rivière massawippi et des ruiddeaux eustis et capel. direction du suivi de l’état de l’environnement., ministère de l’environnement , gouvernement du québec. env/2003/0043, québec, 68p. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset bussière, b. (2005). "principaux défis et pistes de solution pour la restauration des aires d'entreposage de rejets miniers abandonnées." collon, p. (2003). évolution de la qualité de l'eau dans les mines abandonnées du bassin ferrifère lorrain, de l'expérimentation en laboratoire à la modélisation in situ, thèse de l'inpl, nancy. galvez-cloutier, r. and p. j. lefrançois (2005). "les sols contaminés par des métaux lourds : distribution géochimique et techniques de restauration (première partie), vecteur environnement, vol. 38; numéro 3." huang et al. (2007). survey of heavy metal pollution and assessment of agricultural soil in yangzhong district, jiangsu province, china. chemosphere 67, 2148-2155. kalagbor, i., diri, e. (2014). evaluation of heavy metals in orange, pineapple, avocado, pear and pawpaw from a farm in kaani, bori, rivers state nigeria. int. res. j. public environ. health, vol.1 (4), 87-94. kawatra, s. k. and k. a. natarajan 2001. mineral biotechnology : microbial aspects of mineral beneficiation, metal extraction, and environmental control, littleton, colo,, society for mining, metallurgy, and exploration. kleinmann, r.l.p., crerar, d.a. et pacellil, r.r., 1981. biogeochemistry of acid mine drainage and a method to control acid formation, mining engineering, pp, 300-304. krzysztof, l., wiechula, d., korns, i., 2003. metal contamination of farming soils affected by industry, environment international 30, 159–165. lar, u.a., ngozi-chika, c.s., ashano, e.c. (2013). human exposure to lead and other potentially harmful elements associated with galena mining at new zurak, central nigeria. journal of african earth sciences 84, 13-19. levinson, a. a., 1974. introduction to exploration geochemistry, second ed, the applied publ, ltd., wilnette illinois. ministère du développement durable, de l’environnement, de la faune et des parcs (2013). critères de qualité de l’eau de surface. available from world wide web: www.mddelcc.gouv.qc.ca/eau/criteres_eau muller, g., 1969. index of geo-accumulation in sediments of the rhine river, geological journal 2 (3), 108–118. mailto:topacademicjournals@gmail.com http://www.mddelcc.gouv.qc.ca/eau/criteres_eau http://www.mddelcc.gouv.qc.ca/eau/criteres_eau academic journal of science, engineering and technology vol.8, issue 3; may june 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset naicher, e. c. a. t. s. m., 2003. "acid mine drainage arising from gold mining activity in johannesburg, south africa and environs, environmental pollution, 122(1), 29-40. park, j-h., choi, k-k. (2013). risk assessment of soil, water and crops in abandoned geumryeong mine in south korea. journal of geochemical exploration 128, 117123. smedley, p.l., knudsen, j., maiga, d. (2007). arsenic in groundwater from mineralized proterozoic basement rocks of burkina faso. applied geochemistry, 22, 1074-1092. usepa, 2000. abandoned mine site characterization and cleanup handbook, seattle, wash. u.s. environmental protection agency, region 10. zhang et al. (2009). distribution and enrichment of heavy metals among sediments, water body and plants in hengshuihu wetland of northern china. ecological engineering 35, 563-569. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fabrication of biogas digester and production of fuel from animal droppings using high-density polyethylene and polyvinyl chloride okolotu g.i. department of agricultural engineering, faculty of engineering, delta state university of science and technology, p.m.b. 05, ozoro, nigeria. doi: https://doi.org/ 10.5281/zenodo.11121963 abstract: a portable biogas digester was fabricated to obtain combustible methane gas from livestock waste using hdpe plastics and pvc pipes. the structure was made airtight, and fitted with an inlet channel, gas outlet channel, waste outlet channel, and emergency pressure outlet channel. a domestic water purification filter with filtration elements of activated charcoal, iron filings, and local potash was modified for biogas upgrading. all filter composite materials were dried, and mixed with charcoal, potash, and iron filings in the ratio of 4:3:l. leak proofing was done using pvc gum, silicon bonds, and rubber gaskets to ensure gas-tight seals. hdpe thread tape was also used as screw-able elements. upon fabrication completion, a leak test was carried out using one (1) liter of water, and no leakages were observed. the animal droppings of poultry (three bags of 50 kg) were filled into the digester, mixed, and allowed to generate uniform mass for appropriate environmental conditions for microbial processes of anaerobic digestion, involving the breakdown of microorganisms in the absence of oxygen, for the emission of the gas (methane). gas collection was achieved through the outlet pipe (connected from the filter) which is the flexible hose connected to the gas cylinder valve, allowing direct capture of upgraded methane in the metal cylinder. the bill of engineering measurement and evaluation (beme) for the fabrication was made. the obtained methane gas produced was purified able to biomethane, which is burnable to obtain electricity and heat using combined heat and power (chp) plants, usable as fuel, and inject able to the natural gas. keywords: biogas; digester; anaerobic digestion; digestion system designs; biogas applications; biomethane; etc. 1. introduction the world population is on the increase even with a declining growth rate (okolotu and oluka, 2021; okolotu et al, 2024). the need for the conservation of the environment as well as proper management of natural resources is vital for future sustenance. currently around 3.5 mton of biomethane are produced worldwide mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (iea, 2024). europe, asia, and the united states are the major producers. europe, the people’s republic of china (hereafter “china”), and the united states account for 90 % of the global production (iea, 2024). 1.1 biogas: biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen (anaerobic), primarily consisting of methane and carbon dioxide. biogas is a mixture of methane, co2 and small quantities of other gases produced by anaerobic digestion of organic matter in an oxygen free environment (iea, 2024). biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material sewage, green waste or food waste. biogas is a renewable energy source. biogas is produced by anaerobic digestion during which digestion (fermentation) of organic (biodegradable) material occurs inside a closed system (appels et al., 2008). this closed system is called an anaerobic digester, biodigester or a bioreactor. biogas is primarily composed of methane (ch4) and carbon dioxide (co2), and usually contains small amounts of hydrogen sulfide (hs), moisture and siloxanes. methane gas in particular is combustible, and this energy release allows biogas to be used as a fuel. it can be used for any heating purpose, such as cooking. it can also be used in a gas engine to convert the energy in the gas into electricity and heat. biogas can be compressed after removal of carbon-dioxide, the same way as natural gas is compressed and used to power motor vehicles (abatzoglou & boivin, 2009). biogas is considered to be a renewable resource because its production and use cycle is continuous. as organic material grows, it is converted and used. it then re grows in a continually repeating cycle. for future energy security and improvement in the use of natural resources, the depletion of conventional energy resources such as fossil fuel can be solved by the use of renewable energy sources. generation of biogas through anaerobic digestion technology is a renewable energy source. the agriculture chain (from production through processing to use) results in several byproducts. many of which are disposed of as waste. anaerobic digestion provides a means of reducing the hazards associated with the byproducts of agricultural production and processing. the concentration of hazardous gases is reduced, and the resultant sludge is an excellent addition to soil organic matter. this work provides technical details on the fabrication of portable biogas digesters. data generated from this work will be useful in making decisions that will aid the efficient fabrication of larger portable biogas digesters. bio gas collection for anaerobic digestion for production is vital for resource management. a typical example of biogas recovery is presented in figure below; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: details of the elements of a biogas recovery system (epa, 2024) 1.2 anaerobic digestion: anaerobic digestion is a process involving the breakdown of organic matter by micro-organisms in the absence of oxygen. much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion (wikipedia, 2024). a typical digester is a closed system where a certain temperature is maintained and where the released gas is captured, stored and used. an anaerobic digester is a sealed, heated tank which provides a suitable environment for naturally – occurring anaerobic bacteria to grow, multiply, and convert manure to biogas and a low – odor effluent (psu, 2023). the main component of this biogas is methane gas, which is a fuel. methane is also one of the greenhouse gases implicated in global warming. capturing and using the gas therefore help reduce the emission of greenhouse gases to the atmosphere. biogas could be burned directly or used to run an engine that powers an electrical generator, thus producing electricity and heat. the main stages in the anaerobic digestion process are presented below, and each relies on a specific group of micro-organisms. stage i hydrolysis and fermentation: large, insoluble organic molecules are broken down by extra-cellular enzymes through hydrolysis. high amounts of cellulose, or other material that is hydrolyzed slowly, can limit the performance of the entire system (poulsen, 2003). short chain fatty acids (acetic acid, formic acid, etc.) are formed by the enzymes while by products undergo fermentation to produce alcohols, c02. and h2. in this stage, certain bacteria breakdown organic polymers like carbohydrates into simple sugars so that the next group of bacteria can further process the material (tndec, 2024). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset stage il acidogenesis: any short-chain fatty acids longer than acetic acid are oxidized by the acidogenic bacteria to produce formic acid, acetic acid, and h2. valdez vazquez et al., (2004) conducted research on means of promoting the h2 producing feature of acidogenic bacteria for use as an alternative fuel source. stage iii -acetogenesis: this is the third step of biogas production from conversion of organic materials. tndec, (2024) noted that, in this stage, certain bacteria called acetogenic bacteria convert the organic acids into acetic, carbon, and hydrogen. stage iv – methanogenesis: methanogenic bacteria convert the acetic acid and h2 to methane and carbon dioxide. in this stage, certain single cell – called organisms called methanogens convert the intermediate products produced in the preceding stages into biogas (primarily methane and carbon dioxide) (tndec, 2024).the methanogenic are the most unstable among these primary groups of bacteria. figure 2: processing and micro organisms involved in converting organic material to methane and carbon dioxide under anaerobic conditions (poulsen, 2003). figure two (2) indicates the groups in the anaerobic process. group iv can either produce acetic acid or break it down if the concentration of acetate is too high. group v oxidizes acetic acid to h2 and c02 (neither group is central to the basic understanding of anaerobic digestion). figure three (3) below, summarizes the main processes in a simplified flowchart. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: carbon flow in anaerobic environments with active methanogens (ahring, 2003) it is important to note that these processes must be in balance with each other. for example, poulsen, (2003) noted that, if the methanogenic bacteria do not use the hydrogen produced by the acidogenic bacteria almost immediately, the higher hydrogen concentration will increase the production of alcohols and fatty acids, causing the system to collapse. the following are important parameters which must be considered in the design of an anaerobic digestion system; i. temperature: three temperature ranges exist for anaerobic digestion: (i) psychrophilic range between 5o and 25 oc, character sized by slower methane production and longer retention times. (ii) mesophilic range between 30 0 and 40 0c, is the most widely used of the three, and this range balances heating costs with methane production. (iii) thermophilic range from 50 0 to 600 c, produces the most methane but is also the most sensitive, due to fewer bacterial species in existence. once a stable temperature is reached, fluctuations should be kept within 5 0c to avoid killing the desired bacteria. thermophilic tolerance is generally less than that of lower temperatures. each temperature ranges at which the digester can be operated have its own advantages. the thermophilic process has been found to be superior to the mesophilic process from an energy balance and, thus, "profit point of view (ahring, 2003). thermophilic digesters usually achieve better degradation of longchain fatty acids, have a shorter retention time, and require less biomass compared to the quantity of methane produced. the thermophilic process also achieves higher pathogen and weed seed destruction than the mesophilic process alone (el mashad et al., 2004). however, the risk of ammonia inhibition is greater and more energy is required to operate a thermophilic digester. thermophilic processes are considered to be more prone to instability than mesophilic due to fluctuations in input quality. the start up time of thermophilic digesters is however longer than that of mesophilic reactor due to the low numbers of thermophilic bacteria in mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset organic waste. most of the agricultural digesters in the united states are mesophilic (kramer, 2009). the lower heating requirements of mesophilic temperatures translate into lower costs. psychrophilic digesters require a solids retention time approximately twice as long as mesophilic. these digesters require the least amount of energy input. biogas production is slow but gas quality and other parameters indicate favourable process stability. these systems are commonly found in the form of a covered lagoon and, as such, they are usually subject to fluctuations in temperature. ii loading rate: this is expressed as the weight of volatile solids (vs) per unit of volume of digester capacity per unit of time. high loading rates use the digester volume more efficiently. they also increase solids concentration, retention time and alkalinity, which are taken into consideration. iii retention time: the hydraulic retention time (hrt) and solids retention time (srt) are the average lengths of time the liquid or solid portion of manure remains in the digester. generally, the lower the operating temperature (e.g. psychrophilic digestion) the higher the retention time needed. iv solids concentration: this is normally reported as the percentage dry matter and the volatile solid percentage of that dry matter. the solids concentration is necessary to determine the loading rate. the solids concentration also helps to determine the most suitable type of digester. v alkalinity and ph: the methanogenic bacteria have optimum ph conditions ranging between 6.4 to 7.6 (average), while other bacterial species are more tolerant to ph levels outside of this range. 1.3 digestion system designs: different systems have been designed for anaerobic digestion. the following are basic descriptions of the popular systems used on farms. i plug flow system: the plug flow digesters are primarily used at dairy operations that collect manure by scraping (epa, 2024). the plug flow system usually takes the form of a long concrete tank with a slight grade over the length. they are often designed as long, narrow concrete tanks with rigid or flexible cover (abc, 2022). influent is either continuously or intermittently added to one end and flows by gravity to the opposite end. the contents are not mixed mechanically. the retention time is thus a function of channel length, channel grade, and the loading rate. mixed plug flow systems have been used at a wider variety of operations because they can tolerate a broader range of solid concentrations (epa, 2024). ii complete mixed system: this is also known as a completely stirred tank reactor (cstr). the complete mixed system is most commonly a circular tank with a mechanical agitator. the mixing prevents settling and maintains contact between bacteria and the manure. electricity input costs are higher due to the intermittent mixing of the systems. however, the mixing can cause foaming in the tank, which is undesirable because it occupies digester volume and can clog gas lines. complete mix digesters often dilute the mix of feedstock to aid mixing, like the consistency of a thick ‘soup’ (abc, 2022). influent is often added to the digester as effluent is excreted in small quantities at regular intervals. therefore the retention period of manure in a complete mix digester is not necessarily uniform. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset iii fixed film system: the fixed film system contains structures like corrugated plastic drainage pipe inside the vessel to help retain more anaerobic bacteria. the structures increase the surface area available for the bacteria to adhere to, thereby reducing the numbers of bacteria washed out in the effluent. the anaerobic process begins faster and stronger compared to a plug flow or completely mixed system. the advantage of the fixed film system is the shorter retention time a retention time of 20 days in a conventional completely mixed system can be shortened to 4 days with fixed film system. iv covered lagoon: the covered lagoons are typically not heated, so their use is restricted to areas with a relatively warm climate. the hydraulic retention times for covered lagoons range from 40 to 60 days, depending on regional climate. electricity generation is not usually practical with a covered lagoon because biogas production varies with temperature. the covered lagoon systems produce less biogas in colder temperatures and little or no gas below 4 0c. most covered lagoons used to be open manure lagoon on a farm that have added an engineering flexible cover added to capture biogas (abc, 2022). v centralized systems: the centralized systems are much larger anaerobic systems than the typical on farm installation. a number of farms within a designated geographical area are usually required for the economical operation of a centralized anaerobic system. the advantages of a centralized system include less individual risk, favourable economies of scale, and less individual farmer involvement. the disadvantages include the typically high-level costs required to haul inputs and outputs, higher capital costs, and the need for daily management of the system by a trained operator. 1.5 biogas applications: there are many uses for the gas produced by anaerobic digestion. biogas can be substituted for any application designed for natural gas. a boiler will convert the methane to heat. micro turbines, gas turbines, internal combustion engines and fuel cells convert biogas into both electricity and heat. i heat boiler: the heat boilers represent the simplest use of anaerobic produced gas. biogas can be used in heat boilers to directly produce high quality hot water or steam. the hot water or steam may be used to heat the digester and be used in secondary systems such as absorption chillers or space heaters. the gas could also be used directly in any natural gas fired appliance ii flare: there are two basic types of flares available: open and enclosed. the open flares usually consist of a burner with a small windshield. the open flares are usually constructed several metres off the ground in order to protect both workers and supply pipes from the radiated heat. the open flares are mostly suited for temporary or test uses. the enclosed flares are usually ground based permanent structures. the burner is kept in an enclosed cylinder lined with refractory material. the insulation and control of air mixture contribute to a more uniform burn as well as lower emissions. iii internal combustion engines: the use of internal combustion (ic) engines with biogas is long established. ic engines are sub divided into two categories: compression engines, and spark ignition engines. both types of engines may be converted to run using the biogas produced by anaerobic digestion. the biogas operation of compression engines is known as "dual fuel" operation, because a small amount of diesel fuel is combined with mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the gas for ignition purposes. the spark ignition engines are operated on a mixture of biogas and air, as ignition is caused by a spark plug. in a dual fuel engine, a mixture of biogas and air, mixed in an external device is sucked into the engine chamber and ignited with a small amount of diesel fuel. 1.6 biomethane: biomethane (also known as “renewable natural gas”) is a near – pure source of methane produced either by “upgrading” biogas (a process that removes any co2 and other contaminants present in the biogas) or through the gasification of solid biomass followed by methanation (iea, 2024). biogas can be cleaned and upgraded to natural gas standard when it becomes biomethane. bio methanation is the chemical process of creating methane by combining gaseous carbon oxides with hydrogen (eba, 2024). ii materials the materials used in actualization of this work are presented below; the major materials used are the research study areas: agricultural engineering departmental processing laboratory, and agricultural engineering departmental demonstration site, both located in engineering faculty, delta state university of science and technology, ozoro, nigeria. other materials include: hdpe drum, water purification filter, potash, iron sponge, charcoal, hdpe tape, rubber gaskets, pvc gum, silicon bond, socket joints, elbows, tees, valves, pvc and rubber pipes of various size, 25 liters plastic gallon, funnel, gas cylinders, multipurpose thermometer with sensing probe, poultry droppings, water, etc. iii methods a portable biogas digester was produced in the processing laboratory of the department of agricultural engineering, delta state university of science and technology, ozoro. the holding tank was a hdpe drum. a water purification filter was modified as a biogas filter and packed with local potash, activated charcoal and iron filings in order to remove unwanted gases. four openings were provided: a substrate inlet (the coverable pvc pipe on the drum seal for pouring in solvents and solutions after corking the seal), substrate outlet (the pvc pump below the tank for removal of wastes), gas outlet (the pvc plastic pipe attached to the rubber tube, connected to the drum through the seal for the collection of produced gas from fermentation process for appropriate transmission of gas to the cylinder), and emergency pressure valve (the pvc pipe with tap connected, on the drum seal to regulate internal reaction within the gas production unit). upon mixing, at ratio of 1:1 water to poultry droppings, fermentation was allowed for thirty two (32) days in the air tight vessel, and within the period, gas collection was carried out. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset digester fabrication: the biogas digester was made from high-density polyethylene (hdpe) plastic, chosen for durability reasons. the drum was fitted with four openings (substrate inlet, gas outlet; emergency gas release point, and substrate outlet) of circular holes drilled. socket joints were attached with gaskets to the holes to ensure air tight fit. these can be seen in figure four (4) below; figure 4: socket joints and drilled holes. in section i, hole boring was achieved using hot metallic material. this was followed by filing and fitting in (section ii) which gave a resultant functional fitted three openings (section iii) in figure four (4) above. details of the various openings are presented in table one (1) below; table 1: digester openings size and placement s/n type of opening diameter (cm) location 1 substrate inlet 6 top (cover) 2 emergency gas release 4.5 top (cover) 3 gas outlet 4.2 top (cover) 4 substrate outlet 6 base filter fabrication: a domestic water purification filter was modified for upgrading of the biogas. the filtration elements used are activated charcoal, iron filings and local potash, according to orhorhoro et al. (2018). all filter composite materials were dry, and were mixed with the charcoal, potash and iron filings in the ratio of 4:3: l. leak proofing: upon fabrication completion, a leak test was carried out using approximately 1 litre of water to ensure that no leakages were made. the digester was loaded to approximately 60% capacity (about 0.074m3) with poultry droppings in slurry form. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: mixing of the droppings the mixed droppings were further balance by adding more solvent through the inlet unit using the funnel after corking the digester seal. the bill of engineering measurement and evaluation (beme) for the fabrication of the digester was made. iv results the produced digester is presented below; figure 6: biogas digester the result of the filter element produced is presented in figure seven (7) below; figure 7: filter element leak proofing experiment result indicated a gas tight seals. methane gas was produce. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the result of the bill of engineering measurement and evaluation (beme) for the fabrication of the digester is presented in table two (2) below; table 2: bill of engineering measurement and evaluation (beme) for fabrication of the digester s/n item description quantity unit cost (n) total cost naira (n) cost in dollar ($) 1. receptacle hdpe drum 1 35,000 35,000 26.92 2. pressure gauge analog (kpa) 1 19,000 19,000 14.62 3. pipes pvc and rubber pipes of various sizes as reqd. 11,500 11,500 8.85 4. fittings socket joints, elbows, tees, valves, etc. as reqd. 11,550 11,550 8.88 5. glue pvc gum, silicon bond, etc. as reqd. 7,500 7,500 5.77 6. labour specialized labour (plumbing) 22,000 22,000 16.92 7. miscellaneous hdpe tape, rubber for gaskets, etc. as reqd. 8,200 8,200 6.31 8. transport expenses purchase, movement of waste etc. as reqd. 15,000 15,000 11.54 9. filter water purification filter 1 4,000 4,000 3.08 10. filter components potash, iron sponge, charcoal as reqd. 7,000 7,000 5.38 total 140,750 108.27 v discussions in the gas collection, the outlet pipe from the filter which is the flexible hose with a valve at the end, allow for direct capture of upgraded methane in a metal cylinder. retention time affected gas pressure built up in the digester. the gas produced at the beginning of harnessing was low relative to fermentation rate which increased with respect to time. the system produced combustible methane gas at the end of the retention time. gas production was low in the first few days and increases with time. the pvc pipes and fittings connected to the drum served as controls to excessive fermentation products (to avoid explosion from unbalance internal reaction within the tank gas storage). this emergency release valve was fitted with a short length of polyvinyl chloride (pvc) pipe and a valve, in order to make room for emergency release of the pressurized contents. in leak proofing, pvc gum, silicon bond, and rubber gaskets were used to ensure air tight seals. hdpe thread tape was also used as screw able elements. vi conclusion methane gas was produced (from the portable digester) and purify – able to biomethane, which is burnable to obtain electricity and heat using combined heat and power (chp) plants, usable as fuel, and inject – able to the natural gas. recomendation the usage of biogas especially in africa is minimal though it is on the increase, it should be encourage for future sustenance. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset references eba, 2024. about biogas and biomethane. european biogas association. p 11. www.europeanbiogas.eu/about-biogas-and-biomethane/ epa, 2024. how does anaerobic system design and technology. us environmental protection agency. p 1. www.epa.gov/agstar/anaerobic-system-design-and-technology#waste-handling-system iea, 2024. an introduction to biogas and biomethane. international energy agency (iea). p 1, 4 & 8. www.iea.org/reports/outlook-for-biogas-and-biomethane-prospects-for-organic-growth/an-introductionto-biogas-and-biomethane okolotu g. i., akpoghelie p. o., akwenuke o. m., okoronkwo k. a., adaigho d. o., ogbodhu c. u., owheruo j. o., uguru h., & nyorere o., 2024. nutrient compositional characteristics of coconut kernel, palm kernel, cocoa seed, bitter kola, breadfruit and african yam bean. american journal of applied sciences and engineering. vol. 5, issue 1. p 1. doi: https://doi.org/10.5281/zenodo.10892455 tndec, 2024. anaerobic digestion. tennessee state government department of environment and conservation. p 2. www.tn.gov/environment/program-areas/sw-mm-organics/anaerobic-digestion.html wikipedia, 2024. anaerobic digestion. p 1. www.en.m.wikipedia.org/wiki/anaerobic_digestion psu, 2023. anaerobic digestion: biogas production and odor reduction. penn state university extension. p 3. www.extension.psu.edu/anaerobic-digestion-biogas-production-and-odor-reduction abc, 2022. anaerobic digestion. official website of american biogas council. p 3. www.americanbiogascouncil.org/resources/what -is-anaerobic-digestion/ okolotu, g. i., & oluka, s. i. (2021). shore reclamation for agricultural use, a combat to shoreline erosion. advance journal of science, engineering and technology, 6 (5), 14. orhorhoro, e.k. orhorhoro, o.w. & atumah, e.v. (2018). performance evaluation of design ad system biogas purification filter. international journal of mathematical, engineering and management sciences 3(1): 17-27. mailto:topacademicjournals@gmail.com http://www.europeanbiogas.eu/about-biogas-and-biomethane/ http://www.iea.org/reports/outlook-for-biogas-and-biomethane-prospects-for-organic-growth/an-introduction-to-biogas-and-biomethane http://www.iea.org/reports/outlook-for-biogas-and-biomethane-prospects-for-organic-growth/an-introduction-to-biogas-and-biomethane http://www.en.m.wikipedia.org/wiki/anaerobic_digestion http://www.extension.psu.edu/anaerobic-digestion-biogas-production-and-odor-reduction academic journal of science, engineering and technology vol. 9, issue 2; march -april 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset abatzoglou, n. & boivin, s. (2009). a review of biogas purification processes. biofuels, bio-products and bio refining 3(1): 42-71. kramer, j. (2009). wisconsin agricultural biogas casebook. madison: energy center of wisconsin. appels, i., baeyens, jan., degreve, jan. & dewil, r. (2008). principles and potential of the anaerobic digestion of waste-activated sludge. progress in energy and combustion science 34 (6): 755-781. el-mashad, h.m., zeeman, g., van loon, w.k.p., bot, g.p. & lettinga, g. (2004). effect of temperature and temperature fluctuation on thermophilic anaerobic digestion of cattlemanure. bioresource technology 95: 191-201. ahring, b.k. (2003). status on science and application of thermophilic anaerobic digestion. water science technology 30 (12): 241-249. poulsen, t.g. (2003). anaerobic digestion. aalborg: aalborg university press. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset construction management for architects and builders: panacea for sustainable peace and conflict resolution in developing nations 1francis o. uzuegbunam, 2eziyi o. ibem, and 3lawrence a. isiofia 1,2 department of architecture, university of nigeria, enugu campus, 400006, enugu. enugu state, nigeria. 3department of architecture, faculty of environmental sciences, enugu state university of science and technology (esut), agbani. enugu state, nigeria. doi: https://doi.org/10.5281/zenodo.11174558 abstract: this paper focused attention on how the content and nature of study of construction management could be used to create harmonious environment in a construction engagement, free of the usual rancour and acrimony of human nature. it examined the operations of the professionals, supervisors and craftsmen with a view to realising the goals of construction management, which is both social and technical. the analysis of the future for construction management showed that the integration demanded of the industry is at both emotional and operational levels. the ability to coordinate several project activities at once, while analysing and resolving specific problems, is essential for construction management, as is an understanding of engineering, architectural, and other construction management drawings. the environment and man that lives in it act systematically with man as the one in control of the system. he can therefore choose to maintain a balance to this set of interconnected things or parts, to achieve unity, or live with confusion. it therefore becomes imperative that these diverse disciplines and multitude of people must be managed and harmonized in order to optimize the resources available for the benefit of society, in realizing the building project, within the constraints of function, time and cost. that is the basic premise of construction economics, management of man, material and money. keywords: construction management; sustainable peace; conflict resolution; introduction a construction project is a highly emotional place. it is typically a temporary gathering of an average of one hundred people, who come together from various places, for parts of about eighteen months, to assemble and install the products of several manufacturers. those manufacturers are generally larger and often somewhat indifferent to the firms to which they are selling their products. the firms or on-site contractors that actually convert the plans and specifications into a finished project, usually an average of about fifteen in number. some of the fifteen will be the leaders in their trade, while others will be marginal, even insolvent. every type of person will show up at the job site. contrary to all the contract requirements in force on the project, communication at the job site is essentially done on an oral basis. the most successful jobs are those that are set up with as few tiers mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of vertical hierarchy as possible. the job site conversation will loop around the project. discussions and directions will emanate from the person in charge of the field. someone will leave the job office and give a direction, a huddle will occur, and the one in charge of the work will write out his idea on a lunch bag, piece of sheet rock, lumber or some other handy transportable surface that will take a mark. someone will round up a truck, crane, dolly, wheel barrow, and so on, and then forage for what is needed, and the work will get done. communication at the site is verbal. no matter how complicated or technological the design may be, its installation must be first turned into spoken, instructional words to people who are not paper oriented. the typical mechanic has no time for paper. many cannot read and interpret plans, none can read specifications and all of them regard the man with the necktie from any office with distrust. types of construction management contract there are two major management systems used in projects: the general contractor system, and the construction management system. in the general contractor system, the owner hires a general contractor to manage all activities (also known as turnkey projects). working for the general contractor, construction managers oversees the completion of all construction in accordance with the engineers and architect’s drawings and specifications under prevailing building codes. they arrange for trade contractors to perform specialised craftwork or other specified construction work. on small projects such as remodelling a home, self-employed and construction manager or skilled trade worker who directs and oversees employees often is referred to as the construction “contractor”. in the construction management system, the owner hires a firm to oversee all aspects of the project. the management firm will then hire a general contractor to run the construction process and oversee construction of the structure. the manor difference from the general contractor system is that the hired management firm, rather than the owner, works with the individual construction manager. in the design build system, the owners, architects, general contractors and major subcontractors are brought together to cooperatively plan and design the project. the design build group may be from an individual firm or a conglomeration of separate entities. the construction manager participates during the design process and may be in charge of the construction project one the design is agreed upon. construction manager may be owners or salaried employees of a construction management or contracting firm, or may work under contract or as a salaried employee of the owner, developer, contractor, or management firm overseeing the construction project. there are different types of construction management contracts. the type of tendering method adopted by the client/architect influences these contracts. the tendering may by an open tender, which have the advantage of allowing a lot of interested firms, or selective tendering, where a list of firms are invited to bid. the types of construction management contracts:  negotiated contracts  lump sum contract  contract with price variation  package deal negotiated contracts instead of inviting competitive bidding, private owners often choose to award construction contracts with one or more selected contractors. a major reason for using negotiated contracts is the flexibility of this type of pricing mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset arrangement, particularly for projects of large size and great complexity or for projects, which substantially duplicate previous facilities sponsored by the owner. an owner may value the expertise and integrity of a particular contractor who has a good reputation or had successfully worked for the owner in the past. if it becomes necessary to meet a deadline for completion of the project, the construction of a project may proceed without waiting for the completion of the detailed plans and specifications with a contractor that the owner can trust. however, the owner’s staff must be highly knowledgeable and competent in evaluating contractor proposals and monitoring performances. the fixed percentage of fixed fee is determined at the outset of the project, while variable fee and target estimates are used as an incentive to reduce costs by sharing any cost savings. a guaranteed maximum cost arrangement imposes a penalty on a contractor for cost overrun s and failure to complete the project on time. with a guaranteed maximum price contract, amounts below the maximum are typically shared between the owner and the contractor, while the contractor is responsible for costs above the maximum. generally, negotiated contracts require the reimbursement of direct project cost plus the contractor’s fee as determined by one of the following methods: 1. cost plus fixed percentage 2. cost plus fixed fee 3. cost plus variable fee 4. target estimate 5. guaranteed maximum price or cost cost plus fixed fee after calculations, using the basic rates for materials, labour and subcontract, a fixed fee is added and agreed on. cost plus contract in this mode, after using the schedules of rates to arrive at a certain cost, an additional percentage is added for the contractor. there is little incentive in this and the cost plus fixed fee type for the contractor to minimize wastages in the use of materials, as the higher the cost the higher the fee. target cost (with variable fee) the contractor’s fee or profit in this case is not fixed with a percentage or an agreed sum. it is allowed to be flexible depending on the performance of the contractor or depending on agreed varying amounts. thus the builder may end up with a sizeable bonus if he performed efficiently or the client may obtain a discount if the contractor was evidently wasteful. target estimate contract this is another form of contract, which specifies a penalty or reward to a contractor, depending on whether the actual cost is greater than or less than the contractors’ estimate direct job cost. usually, the percentage of savings or overrun to be shared by the owner and the contractor are predetermined and the project duration is specified in the contract. bonuses or penalties may be stipulated for different project completion dates. guaranteed maximum cost contract when the project scope is well defined, an owner may choose to ask the contractor to take all the risks, both in terms of actual cost and project time. any work change orders from the owner must be extremely minor if at all, since performance specifications are provided to the owner at the outset of construction. the owner and the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset contractor agree to a project cost guaranteed by the contractor as maximum. there may be or may not be additional provisions to share any savings if any in the contract. this type of contract is particularly suitable for turnkey operation lump sum contract a lump sum contract is placed either with a bill of quantities or with drawings and specifications. the contract is let on an agreed fixed amount. where there is no boq, the drawings and specifications have to be very detailed. a lump sum contract usually does not allow for fluctuation claims. for it to be successfully managed, alteration or additions must be kept at a minimum. contract with price variation this can also be called a fluctuation contract. this kind of contract is usually placed with boqs, drawings, contract conditions, articles of agreement and details of sub contract works. a clause in the articles of agreement, dealing with fluctuations allow the contract price to be varied once the price of the basic materials and rate of wages change from those listed in the “schedule of price and basic materials and labour rates” at the end of the boq. depending on the particular agreement, most contracts that do not exceed 12 calendar months in duration are not usually allowed to fluctuate in stable economies. package deal the package deal contract is also known as turnkey contract. the contracting firm’s designers prepare the design and these are used in building works. the client thus pays the firm for all services. the design professional in this case works for the contractor and not the client. this system reduces the volume of communications to the minimum since most actors on the scene are under the same roof. types of management contracts let us at this juncture look at some diagrams of functional relationships in the charts below: the full lines represent the contractual relationships, while the dotted lines, represent the day to day interfaces for project implementation. 1. management contract (traditional building industry) client project management --------------------------------- -------------------------------------- design management function ------------------------------------------------------------ contractor fig. 1 construction contractors client carries out overall project management but in this case the project is constructed by using multiple construction contracts led and managed by the management contractor with the approval of the client. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. construction management contract client project management -------------------------- -------------------------------- design construction function management contractor fig. 2 client carries out overall project management but in this case the project is constructed using construction contracts let by the client. he relates directly with the contractors. the construction manager carries out overall management of the construction phase only acting on a supervisory capacity. 3. design and management contract ---------------------- ------------------------------------ design & management contractor fig. 3 in this case client passes to the design and management not only the construction but the detailed design and engineering which has to be developed using conceptual designs which the client has established construction contractors client project management client project management process/ conceptual design design & management contractor construction contractor mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. process plant engineering, procurement and construction contract (e.p.c.) client project management ---------- ---------------------- process/ conceptual ------------------ e.p.c. design contractor -------------------------------------------------------------------------- engineering ------------ procurement ------- construction ------ ------- ---------- ----------- specialist& vendors direct hire sub contractors sub contractors fig. 4 clients hence mat vary the contractor element of the project depending on their own expertise and resource availability. clients will have a group of their own project management personnel monitoring the execution of the work by the contractor and providing the approvals, etc. required by the contractor from time to time. the contractor is responsible for the management and execution of the work within his scope to meet the overall project objectives set by the client’s project management group. 5. project management contract client project management contractor -------------------------------------------------------------------------- engineering procurement construction contractor contractor contractor ---------------------------- ----------- ------------- fig. 5 vendors & subcontractors mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the project management contractor provides the overall project management organization and personnel, manages the contractors on behalf of the client, although the contracts are directly between client and the contractors and/or vendors/subcontractors. 6. project services contractor client project project services management contractor ----------------------------------------------------------------------------- engineering procurement construction contractor contractor contractor -------- --------- ------ contractors vendors contractors & construction fig. 6 the above examples are typical and will be varied from project to project to meet specific needs and circumstances. building contract relationships below are charts showing the varieties of relationships in building contracts. the relationships are indicated as dotted lines for functional and communications whereas the full lines represent the contractual relationship. note that persons in the upper position in each set are responsible for control functions. (i) traditional ------------------------------consultants-------------------------- employer contractor fig. 7 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (ii) project management ------------------------------project manager-------------------- employer consultants contractor fig. 8 (iii) management contract ----------------------- contractor ---------------------------- employer -------------------------------------------------------------consultants fig.9 (iv) design and build employer contractor ------------------------------------------------------------------------- ---------- ------------ consultants consultants fig. 10 breakdown of work programme for construction management the duties of construction management begins at the conception of the project through to the realisation or completion of the work in the field on to the onset of the facility management. these duties are broken down into the following major categories:  the pre-design phase  onset of the design phase  the middle of the design task and the inception of procurement  completion of the design, and procurement of the remaining contracts  project financial control, during construction  work in the field mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the pre-design phase construction management at the pre-design phase includes, but not limited to, project feasibility analysis and market surveys. site investigations and recommendations. master scheduling. creation of the project cost control and estimating system. review of applicable building codes, environmental regulations, and design criteria, local and federal regulations. preparation of the environmental impact statement. onset of the design phase construction management at the onset of the design phase includes, but not limited to, program clarifications. methods and materials research. contractor and supplier lists. on board design reviews. the concept level estimate. using cpm for the design schedule. creating the labour relations program. creating the safety program. value analysis step 1: criteria review and choice on main building systems. tentative separation of bid packages. customizing the general provisions. identifying general conditions. site boring and subsurface analysis. the middle of the design task, and the inception of procurement construction management at this stage includes, but not limited to the choice of construction method, traditional construction method, phased construction, critical part method, or project evaluation review technique method. final establishment of bid packages. tentative level estimates. working drawing estimates. composing the project master schedule to include construction work. preparing invitations for bids. advertising and distributing bidding documents. bid receipt: assisting the owner in establishing responsiveness and responsibility. mobilizing the field operations physical requirements of the field offices. primary general conditions: water, electricity, sanitation, access roads, heat. establishing on site records management requirements, relocation the field staff, site surveys: establishing the footprint of the project. setting procedures and standards of work inspection. contractor payment: procedures and accounting controls. detailed scheduling: incorporating contractors’ cpms and cost breakdowns into the project management plan. completion of the design, and procurement of remaining contracts this includes, but not limited to, final working drawing estimates. bringing the job within the budget testing the market, comparing estimates of the remaining packages with bids already received, value analysis task team studies to eliminate useless costs, adjusting scope to remaining funds, rework on packages still to go to bid. preparing, advertising and awarding the last packages. after the buyout-reallocation contingencies and reserves. project financial control during construction this includes development of managerial tools for accountability and efficient supervision to establish the limits in holdbacks for defective work. holdbacks for poor progress. documenting the disallowances. payment for partially, complete work items. coordinating the payment survey, with the schedule update. tracking the payment process. changes, delays, value analysis and claims. estimating negotiating and processing change orders, encouraging and processing contractors’ value analysis change proposals, keeping accurate track of the cause, duration, and effect of delays. protecting the client against claims: records management, analysing the claims, preparing evidence, expert witness testimony. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset work in the field controlling inter-contract relationships: the special problems of separate primescoordination meetings, general conditions, understanding the two ways to keep order: diplomacy and back charges, making good use of insurances, convincing contractors to trade favours, quick ways to resolve tactical conflicts. scheduling during construction. incorporating contractors’ cpms. showing delays and change orders in the others. demanding and incorporating contractors’ remedial plans. day to day management of the trades. regular routines for the field crew. methods of inspection and testing. diaries, punchiest memoranda and directives. the best way tom use photographs. conversations between the construction manager’s inspectors and the contractors’ superintendents. problems in pursuing the work: unexpected subsurface conditions, severe weather, ambiguous and incorrect document inexperienced contractor personnel, lack of coordination; how the construction manager can save time and money by helping to solve all of these difficulties. conclusion the ability to coordinate several major activities at once, while analysing and resolving specific problems, is essential for construction management, as is an understanding of engineering, architectural, and other construction drawings. good oral and written communication skills are also important, as are leadership skills. construction management involves the establishment of a good working relationship with many different people, the owners, other managers, design professionals, supervisors and crafts men. the building industry could be seen as a disorganized conglomerate, employing the services of all manners of people and various professionals, to carry out one interest and one interest alone, the realization of building project. it therefore becomes imperative that these diverse disciplines and multitude of people must be managed and harmonized in order to optimize the resources available for the benefit of society in realizing the building project, within the constraints of function, time and cost. that is the basic premise of construction economics, management of man, materials and money. bibliography “contact provisions that ensure complete cost disclosures” cost engineering, vol. 29, no. 10, october 1987, pp. 10-14. c.d. sutliff and j.g. zack, j.r., “draw up a bulletproof construction contract” by james and morris carey “liability of construction managers” new york law journal, june 30, 2003, page: 9, vol. 229 by peter s britell, nancy goldstein and alina das “modern construction management” 5th ed. by frank harris and ronald mccaffer “neufert architects data” 3rd ed. ernest and peter neufert “the management of construction” mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may-june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset nimo bassey, “the strategy of contracting for profit” 2nd endition, prentice hall, englewood cliffs, nj, 1986. park, william r. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset design and development of the innosson centre for distance learning (now, general studies building), enugu state university of science and technology (esut), agbani 1isiofia, lawrence adizue, 2uzuegbunam francis onyechi, 3ozoemena chibueze romanus and 4ezea chinonyelum nneoma 1,3.4 department of architecture, enugu state university of science and technology, agbani. 2 department of architecture, university of nigeria, enugu campus. doi: https://doi.org/ 10.5281/zenodo.11449446 abstract: distance learning is a type of teaching and learning in which the students are separated from their teachers and course mates resulting in the students learning remotely without a chance of meeting either their teacher or peer face-to-face, in classrooms. rather, learning instructions are provided online using zoom meetings, e-mail and radios. over time, incessant malpractices in the conduct of examinations trailed its operation and as a consequence, institutions devised means of conducting special lectures for final classes and supervised examinations. the scheme aims to research and design a centre for distance learning with spaces for lecture and seminar spaces which, in turn, will serve as an examination hall. the objectives of the design brief determined the activities in the centre for distance learning, assigned appropriate spaces to the expected activities and zoned the scheduled activities. the brief was taken from the esut administration and was used to interview 10 key personnel in the faculty of education. the survey was carried out in schools that operated the sandwich programmes, business schools, and other certificate schools in enugu state. materials used include digital measuring instruments, compasses, logs, pens, and papers to enter the information on the logs. a site survey was done by the department of survey and geoinformatics, esut and the data provided was used to analyse the site. to scope the capacity of the facility, the design relied on the information from the university authority and the benefactor (innosson group ltd) about the budget. keywords: distance learning, teaching and learning, ict, access to education, esut 1. introduction open distance learning (odl) defines a type of education in which the students or audience are separated from the teachers and class or course mates resulting in the students learning remotely without a chance of contact with their instructors or peers (jimoh, 2013; umezulike, 2015). in this mode of teaching and learning, teachers and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset students do not meet face-to-face in class rooms rather, learning instructions are provided through various media such as the internet, mail (correspondence and e-mail), radio signals and of late, chat lounges and platforms (adebayo, 2007a; uopeople.edu). nowadays, online classes have become a global phenomenon. before now, what was known to many in nigeria was education by correspondence such as the rapid result college, london general certificate of education (gce) and others. distance learning, according to peters (2002 as cited in ikegulu and oranusi, 2014), began as correspondence courses and with increased interest, it became more formalized by the middle of 19th century as a result of industrialisation. in the period, many correspondence institutions sprang up providing tuition to others neglected by the formal education system (ikegulu and oranusi 2014). jimoh (2013), views that developing countries such as nigeria are faced with the challenge of providing quality education to millions of their teaming population stating that national and global experience have shown that it is difficult for conventional education to meet the demands for developing nations like nigeria. jimoh (2013) corroborated his opinion with the carrying capacities of the nigerian universities, joint admissions and matriculation board (jamb) statistics on admissions versus number of applicants from 1995/96 – 2001/2002 sessions and revealed that less than 12% of jamb applicants were successful in the admission within the period. (jimoh, 2013), furthered that out of the 447,928 candidates for university admission in 2008/2009 session, only 153,000 were admitted as a result of the low carrying capacity. perhaps, to chart a way forward, okebukola (2007 as cited in jimoh, 2013), in a keynote address at the 3rd convocation of covenant university made following suggestions:  re-introduction of the higher school certificate.  qualified polytechnics and colleges of education should be given degree-awarding status.  the national open university of nigeria should be strengthened to take in more prospective undergraduates. in another forum, professor julius okojie, the executive secretary, national university commissions (nuc), at a conference, on “increasing access and the quality of university education in nigeria”, 2011, stated that tertiary institutions in nigeria could only admit 250,000 candidates as against the over 1,000,000 annual applicants. to tackle the challenge of access to education in nigeria, nuc licensed additional 46 federal, state and private universities, in the last six years, bringing the number of universities in country to 117. however, despite the addition, access to education continued to pose a challenge” (okojie, 2011). from all these trends, the distance education mode appears to provide the lead way out of the challenges of providing access to education to the teaming world’s population. ikegulu, et al., (2014). access to education and odl discourse can best be discussed in the context of availability of information and communication technology (ict). successful operation of odl require robust ict as an important tool for learning and instructing students (kumpulainen, 2007). however, tertiary institutions of higher learning globally, have predominantly accepted ict as a vital tool for learning and teaching students, staff training and curriculum development, (kumpulainen, 2007; usluel, as_kar, & bas, 2008). by 2007, most institutions of higher learning, world over, have remodeled their teaching and learning processes (pulkkinen, 2007). although information and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset communication technology (ict) has the potentials of improving the education methods, quality of teaching and learning, its advantages are often under-realized (surry & farquhar, 1997). also, its methodology and adoption in institutions of higher learning are sometimes, poorly implemented (taylor, 1998). researchers have expressed concerns on some of the challenges. pelgrum (2001) reported major variations in between teachers in different countries as significant barriers to ict which strengthened the findings of al-senaidi, lin and poirot, (2009). schools in nigeria have somehow, managed to progress in the change with many institutions offering classes in either rented or borrowed spaces for meetings and studios for virtual. by the close of the 2010, the use of (ict), has gained considerably acceptance in many nigerian school system and in other walks of life. the purpose of this brief is to establish the significance of odl and the need for esut to join other institution in establishing the programme with the design and delineations for the proposed distance learning centre as shown in figures 1 – 24 and plates 1 4. aim and objectives aim: to design esut centre for distance learning. the objectives  determined the activities in the esut centre for distance learning.  assigned appropriate spaces to the proposed activities  applied zoning in the activity schedule. 2. literature esut was formerly established in 1980 by an act of anambra state assembly as anambra state university of technology (asutec), with the main campus in amechi, enugu and another campus in awka (okeke, 1992). to take off, a pilot campus was carved out from a part of the facility of the institute of management and technology (imt), campus iii, enugu. during that period, both enugu and ebonyi states were still part of the old anambra state. in 1991, upon the creation of enugu state out of anambra, esut was created out of former asutec and renamed esut, and by 2005, the enugu campus was moved to its permanent campus in agbani town. 3. materials and method survey was restricted to the information provided by the esut administration and operators of esut business school, sandwitch and spadoc programmes peaceland college, enugu. the information received from the interviews was used to develop the initial design brief. the brief was then used to interview 10 key personnel in the faculty of education. the data was obtained using purposive sampling to interview the respondents on the operational mode and features, likely students’ response and staff/student enrolment for minimum space standards. materials used include digital recording devices, digital measuring instrument, compass, logs, pen, and papers to enter the information on the logs. to carryout the site survey, the department of survey and geoinformatics were consulted and the data provided were as shown in figure 1. to scope the capacity of the facility, the design relied on the information from the university authority and the benefactor (innosson group ltd) with regards to the budget. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4. results and discussions the brief the brief from esut specified what is needed to establish the centre as follows 1. area of site: 4576m2 2. 2 nos. lecture halls 3. 2 nos. seminar hall/rooms 4. library 5. administration (registry, bursary unit and programme director’s office) 6. services/circulation spaces brief development table 1. distribution of spaces s/n activities no required a academic 1 lecture and examination halls 2 2 seminar 2 3 library 1 total 5 b administration 1 registry unit 1 2 bursary unit 1 3 director’s office 1 total 3 c circulation and services as necessary source: fieldwork the distribution in table 1 showed the analysis of the brief for proper space allocation to meet the design requirement. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 2. further analysis of the space requirements for development s/n activities provision no required unit space (m2) total space (m2) a academic 1 lecture/exam halls fixed collapsible seating 2 70 140 2 seminar halls/rooms fixed collapsible seating 2 50 90 3 library fixed shelve, desks & seats 1 25 25 b administration 1 registry unit d/r and clerks 1 24 24 2 bursary unit bursary staff 1 24 24 3 director’s office director and secretary 1 30 30 4 staff convenience general staff convenience 2 6 12 5 security unit unit position 1 2 2 c circulation and service spaces 1 conveniences male:4 female:4 2 25 50 2 stairs wells central, service and emergency stair cases 3 10 30 3 circulation hallways and concourse 2 87 200 total 627 source:fieldwork mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset from the distribution in table 2, academic activities, circulation and services took the major bulk of the spaces provided (535m2) in the facility. source: department of surveying and geoinformatics, faculty of environmental sciences, esut, agbani. figure 1. the survey plan of the site. figure 1a. the site area. 57.0 3m 10 certified true copy of original plan made by the department of surveying and geoinformatics (esut) on april 16, 2012 surv. b. o. ekpete geoinformation.com ltd r1434 origin: minna utm (zone 32 ) 75.01m 10m 697039.840 mn 29' 02' area of a = 4576.387 sq.m 20 4° 20 131° 43 ' 40m plan no. esut/sgt/en 003 / 2012 t n figure 1. survey plan showing the site with the: site condition topographic data existing buildigs topographic survey of part of enugu state university of science and technology agbani campus allocated to innoson nkanu west l. g. a. enugu state scale: 1/1500 308° 53' 44° contour interval: 0.2m 53 .8 8m 0 33 82 86 .6 81 m e 93.22m r2 r1 p4 p3 p2 p1 r o a d zenith bank university library (u/c) certified true copy of original plan made by the department of surveying and geoinformatics (esut) on april 16, 2012 surv. b. o. ekpete geoinformation.com ltd r1434 697039.840 mn 29' 75.01m 57.0 3m 20 area of a = 4576.387 sq.m origin: minna utm (zone 32 ) 131° 20 4° 10m 02' 10 t n 308° 53' 43 ' 0 contour interval: 0.2m figure 1a. survey plan showing the site with the: site condition topographic data 33 82 86 .6 81 m e topographic survey of part of enugu state university of science and technology agbani campus allocated to innoson nkanu west l. g. a. enugu state scale: 1/1500 93.22m 53 .8 8m 44° 40m plan no. esut/sgt/en 003 / 2012 r2 r1 p4 p3 p2 p1 r o a d mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 3. zoning of the spaces. s/n activity/function ground floor 1st. floor reason 1 academic lecture/exam halls lecture/exam halls easy access seminar halls/rooms seminar halls/rooms easy access library away from noise 2 administration registry unit for direct contact bursary unit for direct access director’s office away from traffic 3 staff convenience staff convenience staff convenience nearness to users security unit for easy control 4 circulation and service spaces conveniences conveniences at all levels all entry points easy access circulation circulation at all level from the distribution in table 3, the priority the micro zoning of the activities placed priority on circulation and services followed by academic areas in such a manner that it promotes easy flow of functions in the facility. in this way, administrative functions were zoned away from student’s activities but accessed from the circulation points. siting the building, orientation and micro zoning of the factions from the survey map in figure 1, the site is bound on the left by the zenith bank building, on the right, by the university library, at back, by empty space and in the front, by the esut bookshop and access bank separated by the access road. the site terrain is clayey and slopped on two sides from the north down towards south-east and south-west at an average of 1: 15m. see site section figure 2. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset zenith bank r o a d p1 p2 p3 p4 r 1 r 2 308° 29' 93.22m 131° 53' 75.01m 53 .8 8m 20 4° 43 ' 57 .0 3m 44 ° 02 ' survey data analysis of the survey data showed that the site runs on a gradient of 1: 15m from the high a1 to the low point a2. n library figure 2. survey plan showing the site with the site boundaries with: site condition topographic data site section line a1 a2 section a1 a2 figure 2. showing the section through the topography of the site. the analysis of the topography showed that the site gradient to be 1: 15m. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset zenith bank r o a d p1 p2 p3 p4 r1 r2 308° 29' 93.22m 131° 53' 75.01m 53 .8 8m 20 4° 43 ' 57.03m 44° 02' r1434 library n plan-on-site showing the the proposed development on the site at 90° to the slope. figure 3. survey plan showing the site with the site boundaries with the: proposed development on the terrain condition section a1 a2 gradient: 1: 15 figure 3.showing concepts in zoning layout in line with the site features (topography, natural drainage and adjourning buildings). the analysis provided the initial development concepts for the proposal. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset zenith bank r o a d p2 n plan-on-site figure 4. site plan showing: proposed building in relation to topography various access within the site vehicular/pedestrain alignments drainage channels reservation for green and cover ge n e ral pa rkin g sta ff p ark ing lawn verge hedge covers lawn verge hedge covers dri veway dr iv ew ay wal kway wal kway wal kway in out out ge n e ral pa rkin g ge n e ral pa rkin g sta ff p ark ing figurer 4. site plan showing: proposed building in relation to topography various access within the site vehicular/pedestrian alignments drainage channels reservation for green and cover the building orientation was considered best in the north – south orientation in line with the site condition. this way, that the major entry points faced the road away from glare while still open to the prevailing wind and also in alignment with the topography. the micro zoning considered the administrative and management functions and zoned it to the rear so as not to interfere with academic activities while the academic activities was placed in the front for direct access by students. because of the clayey nature of the soil, the design considered reducing load on foundation by adopting hollow pot slab (ribbed floor) and wide strip foundation. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset zenith bank r o a d p2 n site plan figure 5 site plan showing various access within the site vehicular/pedestrain alignments drainage channels reservation for green and cover section a1 a2 g e ne ra l p ark ing sta ff p ar kin g lawn verge hedge covers lawn verge hedge covers proposed buuilding o ut o ut g e ne ra l p ark ing g e ne ra l p ark ing sta ff p ar kin g mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 42 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6. the concept administration tra n s itio n lectures & seminars administration figure 7 analysing figure-6 into actionable form transition circulation & services lectures & seminars c ir c u la ti o n & s e rv ic e s figure 8. further analysis of figure-7 in transition lectures & seminars concept translation transition administration circulation & services seminars & lectures concept development mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 43 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset lectures & seminars figure 11. analysing figure-10 into form lectures & seminars lectures & seminars lectures & seminars lectures & seminars administration figure 9. analysing figure-8 into form concept development -activity zoning administration c ir cu la tio n & s e rv ic es figure 10. analysing figure-9 into form circulation & services circulation & services a d m in is tr a tio n seminar and lecture halls mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 44 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset lecture hall services fo rm c on ce pt 1 de si gn s yn th es is & d ev el op m en t 1 administration se min ar f ig ur e 12 a ss ig n in g fu n ct io n s to a ct iv it y sp ac e. d ev el op m en t of f ig u re 6 i n to d es ig n s e m in a r & le c t u r e h a ll 3 administration circulation 5 900 circulation semin ar & lecture hall services 8 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 45 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset b u r s a r y le ct ur e h al l w as h r e g is tr y w as h convenience security se min ar ha ll r e g is tr y b u r s a r y c o n c o u r s e b u r s a r y fo rm c on ce pt 2 de sig n s yn th es is & de ve lop m en t r e g is tr y convenience f ig ur e 13 . ( op tio n2) as si gn in g fu nc tio ns to a ct iv ity s pa ce . d ev el op m en t o f f ig ur e 11 in to d es ig n e n t r a n c e s e r v ic e s a d m in is t r a ti o n se m in ar a n d le c tu r e h al ls se m in ar a n d le c tu r e h al ls c o n c o u r s e mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 46 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset convenience staff l e c t u r e h a l l 1 bu rs ar y up of fic e 1 up re gi st ry c o n c o u r s e up fo rm c on ce pt 3 de sig n sy nt he sis & d ev elo pm en t se cu ri ty re gi st ry l e c t u r e h a l l 2 fe ma le f ig ur e 14 a & b (o pt io n2) as si gn in g fu nc tio ns to a ct iv ity s pa ce . d ev el op m en t of f ig ur e 11 in to d es ig n up bu rs ar y up ma le circulation s e r v ic e s s e r v ic e s administration administration s e m in a r a n d le c t u r e h a ll s s e m in a r a n d le c t u r e h a ll s concourse mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 47 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f/g1 f/g8 d -e/1 d -e/13 d -e/1 d -e/13 ramp @1 : 7 7-8/a 7-8/h 7-8/a 7-8/h figure 15. ground floor plan foyer e 3 3 0 0 0 up g 5' bursary 9 3 office 1 up 5 2 3 0 0 0 11 a 6 2 lecture hall 1 bursary c f 2 1 0 0 0 h 1 registry wash 10 4 27000 lecture hall 2 13 registry b 12 urinal d' d 1 3000 3 0 0 0 3000 2 7 4 5 c 1420 2 5 5 3750 3 0 0 0 b 1660 3 0 0 0 3750 3 0 0 0 a 1420 3 0 0 0 3000 3 0 0 0 up 12 h wash 3000 3 0 0 0 wash 3000 2 7 4 5 9 wash 3000 2 5 5 8 g wash 3000 3 0 0 0 security up 7 morrow 3000 3 0 0 0 6 f w al l m or ro w 6000 3 0 0 0 4 services 3000 male e 13 3000 female 3000 c onc ourse d 11 3000 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 48 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset d -e / 1 d -e/ 13 7-8/a 7-8/h d -e / 1 d -e/ 13 figure 17. first floor plan 7-8/a 7-8/h f/g1 f/g8 13 24 7 d' male 3 8 13 wash 1 10 wash 17 e d f 5 5' g h female 2 up 7 wash director's office down 19 4 11 3 11 void over foyer below 1 conference hall 2 65 12 21 3 11 14 d c wash e 1 f library g 9 director 4 up 9 23 c onc ourse 2 15 seminar 2 c b 12 b 9 a 6 a h up 13 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 49 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset f g d' figure 18. roof plan a d -e/ 1 d -e/ 13 7-8/a 7-8/h h d -e/ 1 d -e/ 13 12 7-8/a 7-8/h 6 13 30003000 b 30003000 a 11 3000 12 3000 109 3000 8 3000 4 5 7 3 6 2 4 1 3 h 2 2 7 3 5 1 g e 3 0 0 0 f 3 0 0 0 5' d 3 0 0 0 e 3 0 0 0 c 3 0 0 0 d 13 3 0 0 0 b 3000 c 119 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 50 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 112 75 13 5' 4 9 1 10 11 10 3 8 6 8 313 1 9 6 57 12 2412 figure 20. north elevation figure 19. south elevation mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 51 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a f g hd d datum: @100.4m cb datum: @98.8m d' e ah bc d' efg figure 22. east elevation figure 21. west elevation mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 52 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset b 13 3 1 6 0 datum: @100.4m 11 100.4 2 3 0 lower ground level @98.8m 99.2 5' 2 3 0 3 4 0 0 4 clearance for paving f 3 6 5 0 stair well 3 c a 100.6 9 upper ground level @100.4m ribbed floor 3 4 5 0 5 1 g porch h datum: @98.8m d 100.4 stair well ribbed floor 3 4 0 0 26 convenience 1 4 9 2 2 3 0 e datum: @100.4m 12 100.6 100.25 ribbed floor ribbed floor 3 1 6 0 concourse lobby corridor corridor convenience figure 24. section 7-8/h __ 7-8/h lobby figure 23. section d-e/1 __ d-e/13 concourse mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 53 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset a f ig ur e 16 . s ho w in g pl ac em en t o f th e bu ild in g to fl ow w ith th e si te to po gr ap hy p ro fil e 98.6m 98 .0 m 97.0m p2-p3/a1 98.4m 96 .0 m 99 .0 m 96.8m h 98.80m 100.60m p1-p4/a2 98.2m 10 0. 0m 97.80m 100.40m 100.80m 97 .0 m 98.0m 10 1. 0m 97.60m mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 54 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 17 side view as modelled figure 17 rear view as modelled mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 55 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 18 approach view as built mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 56 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 19 rear view as built references adebayo, a. m. (2007a). open and distance learning in south/west geopolitical ado-ekiti, ekiti state. jimoh, m. (2013). an appraisal of the open and distance learning programme in nigeria. journal of education and practice. 4 (3) 213-224 issn 2222-1735 (paper) issn 2222-288x (online). ikegulu, b and oranusi, s, (2014). distance and open learning in nigeria: progress, concerns and prospects. journal of education and practice 5, (35) 167-171 issn 2222-1735 (paper) issn 2222288x (online). okebukola, p. (2007). keynote address during the 3rd convocation of covenant university. concerns and prospects. journal of education and practice. 5(35) 167 171. issn 2222-1735 (paper) issn 2222-288x (online) www.iiste.org kumpulainen (ed.), educational technology: opportunities and challenges (pp. 13–23). oulu, finland: university of oulu. kumpulainen, k. (ed.). (2007). educational technology: opportunities and challenges. oulu, finland: university of oulu. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 3; may -june 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 57 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset okeke, c. n. (1992). science technology and law. lectures and speeches 2. school of law,golden gate university. pelgrum, w. j. (2001). obstacles to the integration of ict in education: results from a worldwide educational assessment. computers and education, 37, 163–178. pulkkinen, j. (2007). cultural globalization and integration of ict in education. in k. al-senaidi, s., lin, l., and poirot, j, (2009). barriers to adopting technology for teaching and learning in oman. computers & education 53 (2009) 575–590 www. elsevier.com/locate/compedu. surry, d. w., & farquhar, j. d. (1997). diffusion theory and instructional technology. journal of instructional science and technology, 2(1) [online]. http://www.usq.edu.au/ electpub/ejist/docs/old/vol2no1/article2.htm retrieved jan 13, 2012. taylor, p. (1998). institutional change in uncertain times: lone ranging is not enough. studies in higher education, 23, 269–278. umezulike, n. a, (2015). evolution and revolution of adult learning: exposition of open and distance learning in nigeria. department of of adult and continuing education, college of agricultural and science education (case), michael okpara university of agriculture umudike abia state nigeria (.gov) https://eric.ed.gov ed570502evolution and revolution of adult learning. uopeople.edu. university of the people. https://www.uopeople.edu/blog/what-is-distance-learning. usluel, y. k., as_kar, p., and bas_, t. (2008). a structural equation model for ict usage in higher education. educational technology & society, 11, 262–273. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 46 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset nigerian commercial sector marine board wood composite hardness assessment 1*chukwudi paulinus ilo, 2chidi kingsley nweke and 3 ephraim ugochukwu nebo 1 department of mechanical and production engineering, enugu state university of science and technology, p.m.b. 01660, enugu, nigeria. 2 works department, university of nigeria teaching hospital, ituku ozalla, enugu state, nigeria. 3department of agric and bio-environmental engineering technology, federal college of agriculture, ishiagu, ebonyi state, nigeria. *corresponding author’s e-mail: chukwudi.ilo@esut.edu.ng *corresponding author’s phone number: +234 814 643 8802 doi: https://doi.org/10.5281/zenodo.17176091 abstract: technical insights on hardness test analysis on marine board plywoods in nigerian market needed by stakeholders to prevent loss of revenue that may arise due to choice of indecorous marine board plywoods for abundant needs as a result of non-availability of such data was investigated. most frequently sought after marine board plywoods were identified, out of which the top three were subjected to test after selection to establish their hardness. each of the samples as required by the leeds hardness tester was prepared and tested four times on the machine for a mean. plots on the hardness of the samples were ensued by computer program from the generated data. results show that marine plex attained aggregate average hardness of 364.5 leeds hardness test (hld), super-plex attained aggregate average hardness of 370.75 hld while nplex attained aggregate average hardness of 392.25 hld. statistically, that nplex is 5.799% and 7.613% harder than super-plex and marine plex respectively. the difference in hardness between super-plex and marine plex is small compared to the difference in hardness between nplex and marine plex which is as much as 27.75 hld. choice of suitable marine board plywoods based on their hardness would be informed by this novel revelation. in the development of their products, biomedical engineers as well as other stake holders should utilize these results. future research attention should be geared towards hardness tests of medium-density fibreboard (mdf) and highdensity fibreboard (hdf) in nigerian economy. keyword: indentation hardness testing, indentation testing, leed hardness test, material hardness testing, material testing, mechanical testing, rockwell hardness test, scleroscope testing, surface hardness testing, vickers hardness. i. introduction background of the study as noted by (fmrl, 2025) the global plywood market valued at usd 50.2 billion in 2024 is expected to grow from year 2025 with projection to reach usd 74.5 billion by the year 2033 at a compound annual growth rate (cagr) estimate of 4.5%. in nigeria, wood composite (plywood) is extensively used across construction, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 47 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset furniture, and packaging industries in nigeria, as it remains a vital engineered wood product. despite abundant raw materials and a fast-growing domestic market, unfortunately nigeria presently remains heavily dependent on plywood imports. the nigerian plywood market valued at usd 8.81 billion in 2023 and being on a growth direction is expected to grow at a cagr of 3.3%, reaching usd 11.05 billion by 2030 as noted by (fmrl, 2025). asserted by ogunwusi, (2012), forestry products industrial goods exports in the 1950’s, 1960’s and 1970’s were once enjoyed by nigeria, even as plywood remains a vital engineered wood product extensively used across furniture, construction and packaging industries in nigeria. wood composites, a derivative of wood product are normally obtained through the processes of binding the particles, strands, boards, or fibers of wood together. from vegetable fibers using lignin-containing materials with chemical additives enabling the integration of polymer and wood flour while helping facilitate optimal processing conditions, similar composite products can also be made. due to an excellent combination of mechanical, thermal and acoustic properties together with a competitive price usually made of materials like rye and wheat straw, sugar cane residue, hemp stalks e.t.c, as observed by (garcia-garcia, et al, 2018), particle and fiberboards are widely used in the building industry as eco-friendly solutions to wood with increasing uses in thermal insulators, ceiling boards, wall partitions, e.t.c. wood composites are engineered to certain specifications resulting in a material that can have diverse applications and this is achieved by the use adhesives. one interesting thing is that wood composites can be created by the use of smaller trees, wood waste materials and hence reduce the need to fell old-growth forests. studying the production of highly environmentally-friendly fiberboards by hot-press molding using posidonia oceanica wastes and a partially biobased epoxy resin as binder, (garcia-garcia, et al, 2018) reveals that there is a remarkable improvement of the mechanical properties with combination of the alkali treatment followed by silanization. higher fire hazards could be experienced when wood composite is compared to solid wood products in terms of challenges associated with it as a result of higher chemical heat content and melting properties. most cheap and common resins usually used in the composites and made with urea-formaldehyde bonded products release toxic formaldehyde in the finished products forming a strong apprehension with wood composite use. though the process of their manufacture as it relates to solid timber demands for extra primary energy, wood composites have numerous advantages. additionally is the humidity-induced warping which is not common in solid woods by some fiber-based and particle based composite woods when they are exposed to moisture. it is interesting to note that the demand for wood composite is on the rise as projected by the earlier statistics due to remarkable improvement on esthetic and mechanical properties of the resulting composites, despite all these challenges stated. (ilo, ajibo, and dim, 2025a) opined that failure of form boards frameworks from wood composites (plywood) especially while the concrete is still not yet set shortly after casting of concretes has been a major source of concern to the construction industry. the purchasing power of the nigerian currency naira in the study of inflation trend pattern and its impact on nigeria’s economy according to (barguma, et al 2022), was seen to be decreasing, a revelation that the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 48 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset economy especially building materials market is badly hit by the inflation. following their quest to assess the effect of building materials cost on housing development in owerri, imo state, eastern region of nigeria by (igboekulie, monye, and joseph, 2022), a very strong relationship has been found to exist between building materials prices and rate of residential development. obaedo, (2024) x-rayed inflation as the most influential factor responsible for increase in the cost of building materials while analyzing the inflation rate and the prices of building materials in benin city, from a correlation analysis, the prices of the building materials had a direct relationship with the inflation rate in nigeria thus the cause for the high cost of building materials. material hardness testing any procedure employed to determine a material’s resistance to scratching, indentation or even deformation is materials hardness testing. by penetration of another harder material, it is simply a test conducted to ascertain the actual resistance exhibited by materials to permanent deformation. objectively, material hardness testing is a mechanical test for material properties which are used in materials development, structural analysis and engineering design and development. usually, it is achieved by pressing a harder material into the surface of the tested material. the size of the resulting indentation which is basically the depth is measured and subsequently converted into a hardness value which indicates how well the material can resist deformation that is permanent. obviously, a number hardness tests exists. in brinell hardness test, a hardened steel or carbide ball indenter is used to create an indentation on the surface of the material being tested while the brinell hardness number (bhn) is calculated from the measured diameter of the indentation. for very soft materials like plastics to provide quick and easy measurement, barcol hardness test is mainly used. vickers hardness test is employed over a wide range of materials from very soft to very hard ones by the use of a square-based diamond pyramid indenter. just like vickers hardness test, knoop hardness test uses a rhombic-based diamond pyramid indenter, and is often used for thin films and brittle materials. shore durometer measures the hardness of rubber and plastics with the use of a spring -loaded indenter while the scleroscope measures hardness by the rebound height of a diamond-tipped hammer that is dropped onto a material. leed hardness test adopted in this research is a dynamic impact test that measures the rebound of a small impactor (indenter) to determine the hardness (hld). ii. literature review ojo and idieunmah, (2021) in their research ecpressed that there is linear relationship between age and strength properties of timber, increasing both the compression and shear strengths and even to a reasonable extent the bending strength. the effect of particle size on the flexural strength, ultimate tensile strength, density and water absorption characteristics of uncarbonized coconut shell/unsaturated polyester composites of particle size 425 microns sample and 170 microns sample were investigated by (iloabachie, et al, 2017) and the result indicated that maximum flexural and ultimate tensile strength were attained at 20wt% for the 425 microns sample. high mechanical properties were found by (elbadawi, et al, 2015) when the effect of adding a blend of tannins to commercial urea formaldehyde (uf) on the particleboard made from wood particles of acacia seyal var. seyal mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 49 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset using the british standard european norm (bsen) relevant standards as compared to the ones produced by solely urea formaldehyde (uf). the mechanical properties tests results were found to show that flexural strength and elongation at break increased as coconut shell proportion got increased when (iloabachie, et al, 2018) studied the effects of carbonized coconut shell (cs) volume fraction on mechanical properties of unsaturated polyester resin (upr) composite. tensile strength of teak wood saw dust – cashew nut shell liquid resin composites was studied by preparing a composite material using a hand layup technique by varying the quantity of the cashew nut shell liquid (cnsl) resin and keeping the saw dust quantity constant by simple methodology of just increasing the percentage of (cnsl). according to the astm d638, tensile strength test on the composites using a universal testing machine (utm) by (ganesan and valarmathi, 2014) revealed that tensile strength of the sample with the highest percentage of (csnl) was the highest and that the tensile increased with increase in (cnsl). conclusively, the tensile strength of the composite is improved with the increase in the cashew nut shell liquid (cnsl) percentage. as a result of research recently conducted on experimental analysis of flexural strength of wood composite (plywood) in nigerian commercial sector (ilo, ajibo, and dim, 2025b) revelled that viewpoint plywood recorded 4.956 n/mm2, plywood eq recorded 9.467 n/mm2 while caledonian, also a make of plywood in nigerian market recorded 16.973 n/mm2 as the maximum stress, modulus of rupture (mor) each of them can withstand while being bent before failing or rupturing. it was observed that coconut fibre reinforced hdpe has 28.6 mega pascal as optimum value for flexural strength while (ihueze, achike, and okafor, 2016) studied performance characteristics and reinforcement combinations of coconut fibre reinforced high density polyethylene (hdpe) polymer matrixes at optimum condition of volume fractions and particle sizes of coconut fibre-filler. in a study conducted to test for the potentials of low-density polyethylene (ldpe) such as plastic films from packaging as resins for saw dust from coconut lumber for the production of wood-plastic composite (wpc) particleboard when the boards were prepared from 50%-80% by weight of lpde to sawdust content, both physical and mechanical properties of wpc evaluated, (valle, 2020) found that the tensile strength, face screw holding and modulus of rupture meet the minimum specifications of the us standards. good interfacial adhesion between sawdust particle and ldpe reduced thickness swelling and improving moisture resistance by diminishing hygroscopy hence expanding the utilization of composites from agricultural wastes and plastic wastes for industrial applications, especially in moist environments, even as well as marine use and humid environment was also revealed by the study. carbonized coconut shell particle reinforced composite recorded the least density value making it desirable in light weight material application through the study by (iloabachie, et al 2014) on the effects of carbonization on the physical and mechanical properties of coconut shell particle reinforced polyester composite. for both physical and mechanical properties, the panels with 50% cc had the most preferred performances in a study by (akinyemi. afolayan, and oluwatobi, 2016) on the properties of developed composite corn cob (cc) and sawdust (sd) particle boards using 100%, 75%, 50%, 25% and 0% variations for both agricultural wastes using formaldehyde as binder at constant volume. empty fruit bunch mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 50 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fibre reinforced polyester matrix composite has the maximum hardness strength of 19.062 n/mm2 which depended greatly on the reinforcement combinations of control factors in a study by (okafor, ihueze, and nwigbo, 2013) on the optimization of hardness strengths response of plantain fibres reinforced polyester matrix composites (pfrp) by application of taguchi robust design. changes were observed on surface quality after 50 reuses with oriented strand board (osb) panels formworks while modification of surface quality was noticed after 80 reuses with marine plywood formworks on the study by (courard, et al, 2012) on evolution of surface properties of concrete through measured lightness and absorption as analysed in the study of panel frameworks. a higher strength value of medium density fibreboards (mdf) composites samples than plywood composites samples was revealed because of the increasing thickness of the activated carbon filler (by aziz, et al, 2015) in their study on the influence of activated carbon filler on the mechanical properties of wood composites. wear behaviours of 9500c carbonized ash were revealed better than those of 8500c and 9000c carbonized ash due to the degree of alteration in the structure of silica by (ozioko, 2011) upon the analysis of the effect of carbonization temperature on wear rate behaviour of rice husk ash reinforced epoxy composites. sgk nordic had the best ultimate flexural strength of 13.568 n/mm2, richard russel had ultimate flexural strength 12.986 n/mm2 while mdf hokusan (mdf) recorded 1.24 n/mm2 as noted by (ilo, nwanjoku, and olayeye, 2025) in a study of flexural strength of medium density fibreboard (mdf) wood composite in nigerian market. joubert (hdf) recorded 15.604 n/mm2, dabar (hdf) recorded 32.604 n/mm2 while sinoply (hdf) recorded 39.248 n/mm2 of their flexural strength at peak when (ilo, nneji, and igede, 2025) studied the flexural strength of high density fibreboard (hdf) wood composite in nigerian market. sinoply, dabar and joubert recorded their peak flexural strength at 0.7979%, 0.3769% and 0.2473% strain respectively. ilo, uro, and edeh, (2025) studied the comparative hardness analysis on nigerian market wood composite (plywood) and found that caledonian attained aggregate average hardness of 407.5 leeds hardness test (hld), view point attained aggregate average hardness of 456.5 hld while plywood eq attained aggregate average hardness of 459.25 hld with the statistical analysis showing that plywood eq is 0.6024% and 12.6993% harder than view point and caledonian respectively. ekundayo, arum and owoyemi, (2022) assessed the flexural strength of glued laminated beams made from local wood species bonded with phenol resorcinol formaldehyde, polyurethane and urea-formaldehyde adhesives and found the values in glulam beams significantly higher than the control (custom wood) especially in edgewise direction. clearly, it is certain from the summary of reviewed literature with regards to their hardness that research has not been directed towards providing technical information on hardness of marine board wood composite in nigerian economy, hence the need for the research in this area. iii. research methodology material mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 51 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset research was made in nigerian market on commonly used and major marine board plywoods in the nigerian market. from the survey made, most common and three major marine board plywoods in top demands in nigerian market were identified. they were selected as samples for analysis. the marine board plywoods samples were super-plex, marine plex and nplex. they are represented accordingly in table 1. in table 1, the samples are coded “αe”, “ωf” and “ꞵg” representing super-plex, marine plex and nplex respectively. they are all prepared according to the requirement by the machine and tested on the machine one after the other. table 1 marine board plywoods samples tested sample αe ωf ꞵg make superplex marine plex nplex equipment a portable non-destructive machine for measuring hardness, the leeds hardness tester as seen in figure 1 which is a type of dynamic hardness test machine was used. it is based on the rebound velocity of usually a small impact body which is the indenter after it strikes the surface of the material. the indenter component of the tester is placed on each sample and device gadget clicked; the indenter pushes to make an indent on the sample. carefully set according to the requirement by the leeds hardness tester in figure 1, the samples (αe) representing super-plex, (ωf) representing marine plex and (ꞵg) representing nplex were all tested on the machine successively. the leeds hardness tester indenter pushes forward to make an impact on the sample by indenting on it as it is operated by placing the indenter of the leeds hardness tester on the sample and clicking the control button. the operation is repeated four times for each sample (make). with computer program, the dynamics of the action of the indenting and the associated resistance, leed hardness (hld) plots are generated. undoubtedly, the plot which is a function of the sample’s composition resulting from their nature shows clearly the relationship between force per unit area and the extent of the impact (indent) in the sample. analysis of the plots generated are made under results and analysis. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 52 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 1: leeds hardness tester iv. results and analysis for each of the samples super-plex, marine plex and nplex, the results of the tests are shown as plots in figures 2, 3 and 4 respectively. essentially, the hardness test results in hld are for the tested samples of the three selected marine board plywoods. plots the figure 2 below is a plot for hardness test result of super-plex sample. the first test recorded 365 hld, the second recorded 387 hld, the third recorded 379 hld while the fourth recorded 352 hld. the aggregate average of the four tests were taken and reported in the figure 5 for a comparative analysis. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 53 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig 2: graph of hardness test results for super-plex in hld the figure 3 below is a plot for hardness test result of marine plex sample. the first test recorded 342 hld, the second recorded 329 hld, the third recorded 377 hld while the fourth recorded 410 hld. the aggregate average of the four tests are taken and reported in the figure 5 for a comparative analysis. fig. 3: graph of hardness test results for marine plex in hld the figure 4 below is a plot for hardness test result of nplex sample. the first test recorded 401 hld, the second recorded 416 hld, the third recorded 381 hld while the fourth recorded 371 hld. the aggregate average of the four tests is taken and reported in the figure 5 for a comparative analysis. superplex 300 400 1 2 3 4 365 387 379 352 h ld tests superplex marine plex 0 500 1 2 3 4 342 329 377 410h ld tests marine plex mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 54 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset fig. 4: graph of hardness test results for nplex in hld the figure 5 below is a plot for aggregate average of the four hardness tests result on super-plex, marine plex and nplex samples. super-plex recorded 370.75 hld, marine plex recorded 364.5 hld while nplex recorded 392.25 hld. fig. 5: graph of aggregate average of hardness test results for super-plex, marine plex and nplex in hld v. conclusion and recommendation in an ascending order of their hardness test results, marine plex achieved aggregate average of hardness test result of 364.5 hld, super-plex achieved aggregate average of hardness test result of 370.75 hld while nplex achieved aggregate average of hardness test result of 392.25 hld. comparatively in terms of hardness, nplex is 5.799% and 7.613% harder than super-plex and marine plex respectively. super-plex is also 1.715% harder than marine plex. these are typically obtained from the result of the tests. this implies that super-plex is nplex 300 350 400 450 1 2 3 4 401 416 381 371 h ld tests nplex 340 360 380 400 superplex marine plex nplex 370.75 364.5 392.25 h ld make aggregate average mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 55 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset harder than marine plex while nplex is harder than super-plex. it is worthy to note that the difference in hardness between super-plex and marine plex is small compared to the difference in hardness between nplex and marine plex which is as much as 27.75 hld. depending on application, choice of marine board plywood from nigeria market can leverage on this novel technical data with respect to their hardness potentials. this novel technical insight should be valued by architects, building contractors, engineers, individuals, construction companies as well as furniture makers. biomedical equipment developers can as well utilise this knowledge. hardness tests analysis of medium-density fibreboard and high-density fibreboard in nigerian market should form future research works in wood composites. references akinyemi. b. a., afolayan, j. o. & oluwatobi, e. o. (2016). some properties of composite corn cob and sawdust particle boards. construction and building materials 127, 436-441. aziz, n. a. a., mohamed, m., mohamad, m, amini, m. h. m., aziz, m. s. a., yusoff, h. and rizman, z. i. (2015). influence of activated carbon filler on the mechanical properties of wood composites. arpn journal of engineering and applied services, 10(1): 376-386. www.arpnjournals.com barguma, w. s., atanda, b. t., chidiebere, u. e, kudirat, b. f., & busola, t. r. (2022). a study of inflation trend pattern and its impact on nigeria's economy. international journal of research publication and reviews, 3(4): pp 5989-5997 courard, l., goffinet, c., migeotte, n., martin, m., pierard, j. and polet, v. (2012). influence of the reuse of osb and marine plywood formworks on surface concrete aesthetics. materials structures (45): 13311343. https://doi/10.1617/s11527-012-9835-0 ekundayo, o. o., arum, c. & owoyemi, j. m. (2022). bending strength evaluation of glulam beams made from selected nigerian wood species. international journal of engineering (ije). (35)11: 2120-2129 elbadawi, m., osman, z., paridah, t., nasroun, t. & kantiner, w. (2015). properties of particleboards made from acacia seyal var. seyal using uf–tannin modified adhesives. cellulose chemistry and technology. 49 (3-4): 369-374. fmrl, (2025). plywood manufacturing in nigeria; the feasibility report. https://businessplansinnigeria.ng/business-plans/plywood-manufacturing-in-nigeria-the-feasibilityreport/#:~:text=since%201997%2c%20annual%20production%20has,%2c%20the%20uae%2c%20a nd%20austria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 56 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ganesan m. and valarmathi t.n. (2014). tensile strength of teak wood saw dust – cashew nut shell liquid resin composites. international journal of engineering development and research (www.ijedr.org) ijedr. 2(1): 196-199. https://rjwave.org/ijedr1401034.pdf garcia-garcia, d, quiles-carrilo, l., montanes, n., fombuena, v. and balart r. (2018). manufacturing and characterization of composite fibreboards with posidonia oceanica wastes with an environmentallyfriendly binder from epoxy resin. materials, 11(1): 35. https://doi.org/10.3390/ma11010035 igboekulie, i. e., monye, c. & joseph, f. f. (2022). assessment of the effect of building materials cost on housing development in owerri, imo state, nigeria. international journal of advances in engineering and management (ijaem), 4(9): 455-474, doi: 10.35629/5252-0409455474 ihueze, c. c., achike, m. k. & okafor, c. e. (2016). optimal performance characteristics and reinforcement combinations of coconut fiber reinforced high density polyethylene (hdpe) polymer matrixes. journal of scientific research & reports. 9(3): 1-10. doi:10.9734/jsrr/2016/20385 ilo, c.p., ajibo, j. i. & dim, e. c. (2025a). flexural strength appraisal of marine board plywood in nigerian market. international journal of recent research in civil and mechanical engineering (ijrrcme). (12)1: (18-24), april-september, issn 2393-8471. doi: https://doi.org/10.5281/zenodo.15753859 ilo, c.p., ajibo, j. i. & dim, e. c. (2025b). analysis of flexural strength of wood composite (plywood) in nigerian commercial sector. international journal of novel research in engineering and science. (12)1: 30-35, march – august, issn 2394-7349. doi:https://doi.org/10.5281/zenodo.15687650 ilo, c. p., nneji, s. n. & igede, g. a. (2025). nigerian market high density fibredoard (hdf) flexural strength evaluation. top academic journal of engineering and mathematics, (10) 4: 27-37, july – august, issn: 2837-2964. doi:https://doi.org/10.5281/zenodo.16410270. ilo, c. p., nwanjoku, t. s. & olayeye e. a. (2025). nigerian economy medium density fibreboard (mdf) wood composite flexural strength assessment. international journal of novel research in interdisciplinary studies, (12) 4: 1-7, july – august, issn 2394-9716. doi:https://doi.org/10.5281/zenodo.16088491 ilo, c. p., uro, u. f. & edeh, j. n. (2025). comparative hardness analysis on nigerian market wood composite (plywood), top multidisciplinary research journal, (10) 4: 1-12, july-august, issn: 29940419. doi: https://doi.org/10.5281/zenodo.16925622 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 57 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset iloabachie, i. c. c., obiorah, s. m. o. & anene, f. a. (2018). study of mechanical properties of carbonized coconut shell polyester composite. journal of engineering and applied sciences. (13): 54-62 iloabachie, i. c. c., obiorah, s. m. o., ezema, i. c., henry, v. i. & chime, o. h. (2014). effects of carbonization on the physical and mechanical properties of coconut shell particle reinforced polyester composite. international journal of research in advanced engineering and technology, 3(1), 62-69, www.engineeringresearchjournal.com. iloabachie, i. c. c., obiorah, s. m. o., ezema, i. c., okpe, b. o., chima, o. m. & chime, a. c. (2017). the effects of particle size on the flexural strength, tensile strength, and water absorption properties of uncarbonized coconut shell/polyester composite. international journal of advanced engineering and technology. (1)1: 22-27. obaedo, b. o., (2024). the inflation rate and the prices of building materials in benin city, international journal of advanced multidisciplinary research and studies, 4(4):1112-1122, doi:10.62225/2583049x.2024.4.4.3158 ogunwusi, a. a. (2012). the forest products industry in nigeria. an international multidisciplinary journal, ethiopia. 6(4), serial no. 27. pp191-205. doi: http://dx.doi.org/10.4314/afrrev.v6i4.13 ojo, o. s. & idieunmah, f. m. (2021). influence of age on the strength of different species of timber. lautech journal of civil and environmental studies. (6)2: 39-46, doi: 10.36108/laujoces/1202.60.0240. okafor, e.c., ihueze, c. c. and nwigbo, s. c. (2013). optimization of hardness strengths response of plantain fibers reinforced polyester matrix composites (pfrp) applying taguchi robust design. international journal of engineering. (26)1: 1-11. doi:105829/idosi.ije.2013.26.01a.01 ozioko, f. u. (2011). effect of carbonization temperature on wear rate behaviour of rice husk ash reinforced epoxy composites. leonardo electronic journal of practices and technologies, (19); 172-182, https://lejpt.academicdirect.org valle, s. (2020). evaluation of the potential of recycled lpde and waste sawdust in wood in wood-plastic composite boards. in the book: 2020 iswa-swis winter school proceedings. solid waste institute for sustainability (swis), the university of texas at arlington mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset soil characterization for texture and moisture properties at spatial data range for potential impact on flooding in ozoro, nigeria *1godspower ikechukwu okolotu, 2chidiebere fabian ozioko, 3okiemute dickson ofuyekpone and 4ike oluka. *1delta state university of science and technology, faculty of engineering, department of agricultural engineering, p.m.b. 05, ozoro, nigeria. 2delta state university of science and technology, faculty of engineering, department of chemical engineering, p.m.b.05, ozoro, nigeria. 3delta state university of science and technology, faculty of engineering, department of materials and metallurgical engineering, p.m.b.05, ozoro, nigeria. 4enugu state university of science and technology, faculty of engineering, department of agricultural and bioresource engineering, p.m.b.01, enugu, nigeria. doi: https://doi.org/10.5281/zenodo.17541787 abstract: soil properties for seven hundred and fifty (750) on–point soil samples were obtained at a depth of 0 – 10 cm below the soil horizon and characterized for their texture type using the jar technique. additionally, the moisture content features were determined before the microwave/oven drying technique was used to assess dehydration under both wet and dry basis conditions, as well as the variation in moisture. these value attributes were used to obtain their impact on the flooding of the area. resultantly, it was found that the soil type of the area was sandy loam soil, while the average moisture values for the area were 5.4059% on a wet basis, 5.8116 % on a dry basis, and 0.4057% variation. the variations in the basis range between 0 – 4 %. thus, a conclusion based on the obtained results prior to the soil properties, which significantly showed normal features attributed to sandy loam soil about water movement, indicating that the area flooding is not basically influenced negatively by the ground type. keywords: soil classification, soil texture, moisture content, soil moisture variation, flooding, etc. 1. introduction mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset there is need for adequate examination of soils [24]. this is useful in soil and water conservation, environmental management, and land use demand for various purposes. the ever-growing population in the world is expected to reach 9 billion by 2050, inciting the need to produce more food to meet the increasing global demands [23]. also, securing and managing the soil require knowledge of soil properties for various decisions making. this research work provides information that will guide scientists, engineers and local land advisers in understanding soil properties for potential productivity of fields, as well as usability. soil classification: the soil is a vital asset of man. it is the base upon which various human activities are carried out. the soil is the cornerstone of an agro ecosystem and a reflection of the potential productiveness of an environment. the soil experiences threats from; soil erosion by water and wind, declines in soil organic matter (som) in peat and mineral soils, soil compaction, sealing, contamination, salinization, desertification, declines in soil biodiversity [13], flooding, etc. soil classifications are typically named for the primary constituent particle size or a combination of the most abundant particles sizes (e.g. sandy clay, silty clay) [7]. soils are classifiable through their particle sizes using various classification systems approved by appropriate bodies. examples are: the british standard institution, the international union of soil science (iuss), the united states department of agriculture (usda), and the united states public roads administration (uspra). the soil classification system using their particle sizes developed by these international bodies are presented in figure one (1) below; figure 1: classification of soil particle according to size by four systems [8] soil characteristics: soil is a natural body comprised of solids (minerals and organic matter), liquid, and gases that occurs on the land surface, occupies space, and is characterized by one or both of the following: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset horizons or layers that are distinguishable from the initial material as a result of additions, losses, transfers, and transformations of energy and matter in a natural environment [4]. the soil is a natural resource that exists in there major particle forms which are ever available on earth (clay, sand and silt). a soil can be all sand, all clay, or all silt in rare case, though most soils are a combination of the three [9]. soils perform vital functions to sustain plant and animal life, regulate water flow, filter and buffer pollutants, cycle nutrients, and provide physical stability and sort [4]. the soil also receives beneficial support from them. [25] noted that, the root systems of live plants act in several ways to increase slope stability and serve as a binder for individual soil particles. it is teaming with billions of bacteria, fungi, and other microbes that are the foundation of an elegant symbiotic ecosystem [5]. the soil is a renewable resource. they are considered renewable because they are constantly forming [9]. soil formation process takes decades to occur. soil formation rates vary across the planet: the slowest rates occur in cold, dry regions (1000+ years), and the fastest rates are in hot, wet regions (several hundred years) [9]. soils have four main components: mineral particles (sand, silt, and clay), organic matter, water, and air [10]. soil contains these nutrients and minerals because of the physical, chemical, and biological forces that form soil, the composition of the parent material from which soils were formed, and the ability of soils to capture, retain, and transform compounds as those compounds enter and move through their environment [11]. soil texture: texture affects many soil properties, such as infiltration, structure, porosity, water holding capacity, and chemistry [7]. the soil texture is associated with soil porosity, which in turn regulates the water holding capacity, gaseous diffusion and water movement that determines the soil health [21]. the soil water holding and movement influence varieties of factors in the soil environment. the smallest mineral particle in soil is clay. clay particles are the active portion of a soil. this is because chemical reactions occur at their surface. the chemical reactions control the adsorption and many other chemicals in the environment. sand and silt particles are less active chemically because of their mineral composition and limited surface area. this is because there particle sizes are bigger than clay. texture affects many soil processes, including infiltration, drainage (water and air distribution), erosion, chemical processes, and biologic processes [16]. soil moisture content: moisture content is defined as the ratio of the weight of liquid in the soil to that of the solid. moisture content is an important physical property index for evaluating the physical and mechanical properties of soil [14]. soil moisture (sm) content can be defined as the amount of water available in the unsaturated zone [19]. in engineering practice, soil moisture content plays an important role in the safety performance evaluation of various geotechnical engineering structures (such as soil nailing wall, foundation, earth rock dam, etc.), slope treatment and reinforcement, landslide and debris flow early warning, ground collapse prevention and control, etc., [14]. soil moisture content material has paramount importance in dictating mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset engineering, agronomic, geological, ecological, bioorganical, and hydrological features of the soil mass [18]. it influences plant growth, soil temperature, transport of chemicals and groundwater recharge [23]. the two types of soil moisture measurements are the direct (volumetric, gravimetric, and methyl alcohol methods) and the indirect methods (gypsum block, tensiometer, neutron probe, and pressure gauge: pressure plate and pressure membrane). the volumetric method involves obtaining soil samples using a tube auger of a known volume and obtaining the amount of water present in the sample using appropriate formula upon oven drying. the gravimetric methods involves measurement of soil moisture from soil samples of known weight or volume through weighing, drying and reweighing to obtain the difference in amount of dryness and wetness of the soil sample. the methyl alcohol technic involves mixing a known volume of methyl alcohol and obtaining the change in specific gravity of the solution using the hydrometer. the gypsum blocks are rectangular shaped blocks of materials like gypsum, nylon fiber, glass, etc., made up of a ceramic or clay cup of 7.5 cm, a cap for closure, a vacuum gauge and a hollow metallic tube. they operate on the principle of conductance of electricity through the electrodes. tensiometer is used to obtain amount of tension or the tenacity upon which water is held in by soil. thus, upon water fillage of the tensiometer placed in the soil, the gauge records the degree of vacuum due to the dryness of soil prior moisture obtained from the cup. neutron probe and pressure gauge involves the use of neutron meters as well as pressure gauge in obtaining the moisture in the soil through the use of radio nuclides or radioactive materials. neutron probe of source like americium and beryllium, radium and beryllium etc., is lowered into access tube (basically 50 -100 cm) at the desired depth in the soil and fast neutrons are released into the soil, and upon neutrons encounter with nuclei of hydrogen atom of water, their speed is reduced and the rate meter counts the number of slow neutrons, which are directly proportional to water molecules which are used to obtain the moisture content of soil from the calibration curve with the counts of slow neutrons. jar technique analysis: generally, mechanical analysis is a process of soil test in the laboratory. the jar test is a simple experiment that gives the relative proportions of sand, silt, and clay in the soil, which together determine the soil’s texture [12]. it is one of the most important laboratory determination made in soil studies [8]. it is divided into two major types: sieve analysis and hydrometer analysis. sieve analysis involves the shaking of soil samples through a set of sieves of different sizes that have smaller openings of approximately 5mm and below. the sieve analysis is suitable for coarse grained soil i.e., the soil having particle size greater than 75 microns. hydrometer analysis is the process of testing soil based on the principle of sedimentation of soil grains in water. hydrometer analysis is further developed to sub types of which the jar technique emerged from. when a soil specimen is dispersed in water, the particles settle at different velocities, depending on their mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset shape, size, weight, and the viscosity of the water. this is the principle governing the jar technique in a known sized container. flooding: flood otherwise inundation, deluge, flash flood, downpour, freshet, torrent, swamping, overflow, spate, cloudburst, etc. flood refers to the ponding of water at or near the point where the rain fell [1]. it occur as a result of heavy rainfall, snowmelt, ocean or sea wave action on shores, water body overflow. it is regarded as flash flood when caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours [1]. flood is a threat to lives, destroying belongings, damage infrastructures, inundate businesses and properties, hinder access to places, displaces people and residents, etc. these floods are threats to agriculture. agricultural farms and crops are submerged upon the occurrence of these flood events. moreover some crops do not have resistance to water submersion conditions, and thus suffer the effects more. in 2022, the pond news reported of the submersion of the delta state university of science and technology ozoro. also, in 2015, the area (ozoro) witnessed high flooding with hundreds of person displaced from their homes with etevie, iyeriri and urhuamudhu communities identified with higher damage. these highlighted flood scaneros as a problem that needs solution in the area. this solution have been delayed due to possible fund acquisition calling on government and nongovernmental bodies to interceed, as this will serve as a major community development for the area. [17] reported that the overall impact of flood varied across selected states: bayelsa (99 percent) jigawa (94 percent), nasarawa (70 percent), kogi (70 percent), delta (57 percent) and anambra (23 percent). this puts delta state among the frontline of flood vulnerability in the country. in same period, [2] recommendably highlighted the need for residents in "abraka, agbor, asaba, umuakwata, aboh, ozoro, oleh, otu-jeremi and other coastline communities, as well as persons living in floodplain areas to immediately relocate temporarily to upper land, taking with them valuable properties, children, people with disabilities and the elderly family members". in all, flood is a problem in the area. 2. materials the study area is ozoro in delta state of nigeria. ozoro is located in isoko north local government area. it is popularly known for its educationally attributed history with higher institutions (ozoro college of education and the defunct delta state polytechnic, ozoro) of which delta state university of science and technology have emerged from, at present known as southern deltan university, ozoro. the soil and water laboratory section of the department of agricultural engineering of the delta state university of science and technology, ozoro was deployed for sample analysis. other materials used in this study include the following: materials used for soil test (soil auger, plastic sack, detergent, distilled water, electric oven, textural triangle, etc), weighing balance, and materials used for moisture experiment (soil samples, plastic sac, plastic tape, microwave, etc). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 3. methodology a total of seven hundred and fifty (750) on – point soil samples were scientifically obtained from selected fifty (50) on – site different sub – sectional locations within the study area, using the soil auger at appropriately 10 cm vertical depth meeting the collection global standard range of the 0 15 cm depth. the samples were bagged and labeled using black plastic sacks and paper tape, and upon grouping, taken to agricultural engineering department laboratory for necessary tests. a typical soil sampling and measurement are presented in figure two (2) below; figure 2: soil sampling and soil measurement using the weighing balance i. soil type experimentation: the mechanical analysis technique of laboratory procedure for soil separation identification was utilized. according to [20], the percentage height of each measured soil components were used to trace their soil type (using the lines from the percentage values on the textural class diagram) presented in figure three (3) below; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: soil textural class diagram [22; 20]. prior these methods, other replicates experiments were attained for their obtained samples. ii. soil moisture content: the moisture content (%) of the soil samples were obtained upon weighing, the soil samples were dried in an oven at 105 oc for 24 hours, and reweighed for measurements and computations. this was based on the difference in weight of the soil (wetness to dryness). moisture content is expressed as a percentage by weight of either total product (wet basis) or dry product (dry basis). [3] mathematically explain moisture content as presented below; wet basis moisture content: m = 100 x (wet weight – dry weight) / wet weight dry basis moisture content: m = 100 x (wet weight – dry weight) / dry weight the computations were done using the wet basis moisture content equation above, in alignment with the guidelines of [6] as presented below; where: w1 = weight of petri dish + sample before drying; w2 = weight of petri dish + sample after drying; w1 w2 = moisture loss prior these methods, other replicates experiments were attained for their obtained samples. also, obtained values were used to assess the possible or negative impact of the soil on the area flooding. 4. results the results obtained in the course of this work are presented in tables 1 3 and figures 5 8 below; table 1: soil composition and types exp. no. sandy ml clay ml silt ml total soil % sandy % clay % silt soil type 1 30 11 5 46 65 24 11 sandy clay loam 2 43 4 11 58 74 7 19 sandy loam 3 52 0 6 58 90 0 10 sand 4 39 10 2 51 76 20 4 sandy loam 5 48 8 2 58 83 14 3 loamy sand 6 46 12 1 59 78 20 2 sandy loam 7 29 23 6 58 50 40 10 sandy clay 8 32 18 8 58 55 31 14 sandy clay loam 9 51 13 0 64 80 20 0 sandy loam mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 10 48 18 3 69 70 26 4 sandy clay loam 11 46 1 0 47 98 2 0 sand 12 45 2 0 47 96 4 0 sand 13 30 20 2 52 58 38 4 sandy clay loam 14 41 2 0 43 95 5 0 sand 15 48 6 0 54 89 11 0 loamy sand 16 42 0 14 56 75 0 25 loamy sand 17 46 2 0 48 96 4 0 sand 18 48 2 0 50 96 4 0 sand 19 45 2 0 47 96 4 0 sand 20 50 2 0 52 96 4 0 sand 21 22 20 8 50 44 40 16 sandy clay 22 40 16 20 76 53 21 26 sandy loam 23 53 0 1 54 98 0 2 sand 24 48 1 21 70 69 1 30 sandy loam 25 47 2 9 58 81 3 16 loamy sand 26 52 0 2 54 96 0 4 sand 27 24 1 11 36 67 3 31 sandy loam 28 32 4 3 39 83 10 8 loamy sand 29 24 2 12 38 63 5 32 sandy loam 30 20 1 9 30 67 3 30 sandy loam 31 34 4 1 39 87 10 3 loamy sand 32 17 1 8 26 65 4 31 sandy loam 33 17 3 8 28 61 11 29 sandy loam 34 18 2 12 32 56 6 38 sandy loam 35 24 1 16 41 59 2 39 sandy loam 36 19 1 9 29 66 3 31 sandy loam 37 29 4 1 34 85 12 3 loamy sand 38 31 6 1 38 82 16 3 loamy sand 39 33 6 2 41 80 15 5 loamy sand 40 31 1 7 39 79 3 18 loamy sand mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 41 28 1 10 39 72 3 26 sandy loam 42 32 5 2 39 82 13 5 loamy sand 43 34 5 2 41 83 12 5 loamy sand 44 29 7 2 38 76 18 5 sandy loam 45 31 9 2 42 74 21 5 sandy loam 46 22 14 1 37 59 38 3 sandy clay loam 47 14 3 4 21 67 14 19 sandy loam 48 13 2 4 19 68 11 21 sandy loam 49 16 1 2 19 84 5 11 loamy sand 50 14 2 3 19 74 11 16 sandy loam av. 34 6 5 45 76 12 12 sandy loam the results of soil moisture properties obtained are presented in table two (2) below; table 2: results of soil moisture variables exp. no. weight of empty petri dish (g) weight of wet soil sample (g) weight of dry soil (g) moisture loss (g) 1 35 80.5 77.7 2.8 2 38.7 89.4 85.6 3.8 3 39.1 75.1 66.5 8.6 4 36.4 74.3 71.2 3.1 5 40.7 87.0 84.0 3.0 6 39.4 83.5 81.0 2.5 7 36.1 72.0 69.2 2.8 8 38.4 71.5 69.3 2.2 9 30.0 78.1 74.0 4.1 10 40.8 75.6 75.1 0.5 11 36.7 75.4 72.8 2.6 12 39.6 81.9 79.2 2.7 13 35.3 78.0 75.6 2.4 14 39.3 73.0 71.1 1.9 15 36.2 71.5 69.3 2.2 16 38.9 79.5 77.2 2.3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 17 38.2 86.7 83.8 2.9 18 40.9 93.6 90.1 3.5 19 36.9 88.2 83.6 4.6 20 36.9 81.2 76.8 4.4 21 39.6 72.8 66.4 6.4 22 35.4 72.3 69.2 3.1 23 39.2 69.2 66.3 2.9 24 38.8 69.7 67.1 2.6 25 36.7 74.3 71.2 3.1 26 38.0 70.7 68.2 2.5 27 38.0 82.2 79.2 3.0 28 39.0 92.7 87.4 5.3 29 36.7 78.0 75.6 2.4 30 40.7 74.9 70.8 4.1 31 36.6 82.7 79.0 3.7 32 35.0 68.9 65.1 3.8 33 38.7 81.8 77.7 4.1 34 36.0 78.3 71.2 7.1 35 40.7 94.0 85.9 8.1 36 36.0 74.3 71.5 2.8 37 39.0 87.7 81.5 6.2 38 36.7 85.3 78.9 6.4 39 38.0 68.0 63.8 4.2 40 38.6 85.5 78.3 7.2 41 36.6 80.0 74.0 6.0 42 38.7 85.5 79.1 6.4 43 35.0 90.0 86.3 3.7 44 38.0 93.8 77.6 16.2 45 36.6 84.4 79.2 5.2 46 36.0 78.9 75.3 3.6 47 36.6 75.2 69.9 5.3 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 48 36.7 81.5 76.2 5.3 49 38.0 74.9 68.5 6.4 50 39.1 68.5 61.6 6.9 av. 37.6 79.4 75.1 4.3 results of moisture content values are presented in table three (3) below; table 3: the results of moisture content in wet basis, dry basis, and variation exp. no. moisture content (%) wet basis dry basis basis variation 1 3.4783 3.6036 0.1253 2 4.2506 4.4393 0.1887 3 11.4514 12.9323 1.4809 4 4.1723 4.3539 0.1816 5 3.4483 3.5714 0.1231 6 2.9940 3.0864 0.0924 7 3.8889 4.0462 0.1573 8 3.0769 3.1746 0.0977 9 5.2497 5.5405 0.2908 10 0.6614 0.6658 0.0044 11 3.4483 3.5714 0.1231 12 3.2967 3.4091 0.1124 13 3.0769 3.1746 0.0977 14 2.6027 2.6723 0.0696 15 3.0769 3.1746 0.0977 16 2.8931 2.9793 0.0862 17 3.3449 3.4606 0.1157 18 3.7393 3.8846 0.1453 19 5.2154 5.5024 0.2870 20 5.4187 5.7292 0.3105 21 8.7912 9.6386 0.8474 22 4.2877 4.4798 0.1921 23 4.1908 4.3741 0.1833 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 24 3.7303 3.8748 0.1445 25 4.1723 4.3539 0.1816 26 3.5361 3.6657 0.1296 27 3.6496 3.7879 0.1383 28 5.7174 6.0641 0.3467 29 3.0769 3.1746 0.0977 30 5.4740 5.7910 0.3170 31 4.4740 4.6835 0.2095 32 5.5152 5.8372 0.3220 33 5.0122 5.2767 0.2645 34 9.0677 9.9719 0.9042 35 8.6170 9.4296 0.8126 36 3.7685 3.9161 0.1476 37 7.0696 7.6074 0.5378 38 7.5029 8.1115 0.6086 39 6.1765 6.5831 0.4066 40 8.4211 9.1954 0.7743 41 7.5000 8.1081 0.6081 42 7.4854 8.0910 0.6056 43 4.1111 4.2874 0.1763 44 17.2708 20.8763 3.6055 45 6.1611 6.5657 0.4046 46 4.5627 4.7809 0.2182 47 7.0479 7.5823 0.5344 48 6.5031 6.9554 0.4523 49 8.5447 9.3431 0.7984 50 10.0730 11.2013 1.1283 av. 5.4059 5.8116 0.4057 the wet basis moisture content is presented in figure four (4) below; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: wet basis moisture content the dry basis moisture content is presented in figure five (5) below; figure 5: dry basis moisture content the variation in basis is presented in figure six (6) below; mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 6: moisture variation in basis for all experiments the moisture loss for all experiments is presented in figure seven (7) below; figure 7: moisture loss for all experiments 5. discussions from results obtained, the area has a sandy loam soil. this is dominatively present with loamy sand. this was obtained from most occurring soil type from the products of laboratory analysis and their values in the textural triangle which is equipped with all possible combinations of soil separation results. this triangle makes it flexible for all types of soil separation experiments. also, sandy loam soil is regarded as the magic soil, with the sand comprising the largest amount, followed by silt, and a smaller part of clay. sand particles are generally more solid and larger than other soil particle types, thereby possessing the capacity of allowing water to move through them more easily. silt and clay on the other hand are good in water retaintion. sandy loam soils possess well-balanced capacity for water holding, form a stable structure, as well provide sufficient aeration. [16] noted that these properties also affect suitability of soil for different uses, such as stormwater infiltration. from results obtained, the moisture content were however within the range of 0 – 20 %. this is relatively characterizable to a low moisture content class. this is attributed to low water concentration in the soil pores of the area. moreso, the results points to the soil properties at the uppermost layer of the soil. however, [15] reported that soil moisture controls the propagation of floods by delaying or accelerating the accumulation of rainwater in the runoff cycle. soil moisture characterization over a spatial domains is a key determininant of the movement of water within the land-atmosphere continuum. in figures four (4) and five (5) above, there exist a great correlationship between the two properties of moisture presence in the soil. this can be seen from their curve patterns. these two curves also influenced the curve pattern of moisture loss in figure seven (7). [11] reported that "the texture and historical nature of soils affects how they respond to moisture extremes like floods mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and droughts". thus, both properties posses the ability of influencing the flood behavior of the area. however with the nature of soil in the area, their influence were minimal. from general results obtained, the soil properties does not posses significantly varying features capable of influencing the area flooding. finally, in addition to other significant influencable variables, installation of appropriate surface and subsurface drains is a perceived recommendable solution to this flooding incidence. soil or land reclamation strategies for swampy regions have proven useful in various location and thus may also be deployed in required locations of the area. moreso, this work provides the simplicity in laboratory and experimental approach of soil analysis, which may be beneficial within and farest of the study area. 6. conclusion from results obtained and discussion made, it was therefore concluded that; the soil properties of the study area was sandy loam. the area has low moisture content of 0 – 20%. at average, the soil has moisture loss of 4.3g, and moisture content of 5.4059 % on wet basis, 5.8116 % on dry basis and 0.4057 % variation. the variations in the basis were between 0 – 4 % difference. also, based on obtained results stated and discussed above, the soil properties possess normal features attributed to sandy loam soil with regards to water movement. thus, it was concluded that, the soil type and moisture features contributed little or no negative impact on the area flooding. generally, sandy loam has moderate impact on flooding, due to its attributed good drainage and reduction in waterlogging risk. though its high infiltration rate features contribute to groundwater recharge of the area during flood events. references noaa nws, 2025. flood and flash flood definitions. national oceanic and atmospheric administration of national weather service. p 1. www.weather.gov/mrx/flood_and_flash dsob, 2024. flooding: state bureau advises deltans to brace up as rainfall worsen. delta state orientation bureau. p 1. https://newmedia.deltastate.gov.ng/2024/09/25/flooding-state-bureau-advises-deltans-tobrace-up-as-rainfall-worsen/ kpm, 2024. principles of moisture measurement. p 3. kpm analytics of union park capital, westborough, ma. www.kpmanalytics.com/articles-insights/principles-of-moisture-measurement nrcs, 2024. resources: soil. natural resource conservation service of the united state department of agriculture (usda). p 1. www.nrcs.usda.gov/resources/education-and-teaching-materials/whatmailto:topacademicjournals@gmail.com https://www.nrcs.usda.gov/resources/education-and-teaching-materials/what-issoil#:~:text=soil%20%2d%20soil%20is%20a%20natural,of%20additions%2c%20losses%2c%20transfers%2c academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset issoil#:~:text=soil%20%2d%20soil%20is%20a%20natural,of%20additions%2c%20losses%2c%20tra nsfers%2c nrcs, 2024. soil. natural resource conservation service of the united state department of agriculture (usda). p 1. www.nrcs.usda.gov/conservation-basics/natural-resource-concerns/soils/soil-health okolotu g. i., adaigho d.o., akwenuke o.m., oluka s.i., udom e.a., & uguru h., 2024. proximate analysis of processed cashew nut (anacardium occidentale l.) an agricultural processed food produce. international journal of engineering and environmental sciences, 7 (1). p 5. https://doi.org/10.5281/zenodo.10776017 pca, 2024. soil classification. minnesota stormwater manual. pollution control agency. p 3. https://stormwater.pca.state.mn.us/index.php?title=soil_classification#:~:text=soil%20textures%20are %20classified%20by,sandy%20clay%2c%20silty%20clay) shreedja d., 2024. mechanical analysis of soil: meaning, process and principles. soil management. p 2. www.soilmanagementindia.com/soil/mechanical-analysis-of-soil-meaning-process-and-principles/1710 sssa, 2024. soil basics. soil science society of about soils. p 4. www.soils.org/about-soils/basics umde, 2024. soil basics. university of maryland extension. p 2. https://extension.umd.edu/resource/soilbasics/ usde, 2024. science: soil explained. us department of energy. p 3. www.energy.gov/science/doeexplainssoil rfu, 2023. jar test. the rockefeller university, new york. p 1. https://rockedu.rockefeller.edu/component/jar-test/ vanino s., pirelli t., bene c., bøe f., castanheira n., chenu c., cornu s., feiza v., fornara d., heller o., kasparinskis r., keesstra s., lasorella m.v., madenoğlu s., meurer k.h.e., sullivan l., peter n., piccini c., , siebielec g., smreczak b., thorsøe m.h., and farinaa r., 2023. barriers and opportunities of soil knowledge to address soil challenges: stakeholders’ perspectives across europe. p 3. www.ncbi.nlm.nih.gov/pmc/articles/pmc9693670/#bib22 mailto:topacademicjournals@gmail.com https://www.nrcs.usda.gov/resources/education-and-teaching-materials/what-issoil#:~:text=soil%20%2d%20soil%20is%20a%20natural,of%20additions%2c%20losses%2c%20transfers%2c https://www.nrcs.usda.gov/resources/education-and-teaching-materials/what-issoil#:~:text=soil%20%2d%20soil%20is%20a%20natural,of%20additions%2c%20losses%2c%20transfers%2c https://www.nrcs.usda.gov/conservation-basics/natural-resource-concerns/soils/soil-health https://doi.org/10.5281/zenodo.10776017 https://extension.umd.edu/resource/soil-basics/ https://extension.umd.edu/resource/soil-basics/ https://www.energy.gov/science/doe-explainssoil https://www.energy.gov/science/doe-explainssoil https://www.ncbi.nlm.nih.gov/pmc/articles/pmc9693670/#bib22 academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset he f., chen j., li c., and xiong f., 2022. temperature tracer method in structural health monitoring: a review. science direct. p 1. www.sciencedirect.com/topics/engineering/soil-moisture-content ibrahim h.d., peiyuan l., sharma a., kristovich d., khadse t., wuebbles d.j., 2022. effects of soil moisture on flooding and strategizing place-based nature-based solutions in urban watersheds: a case study from the chicago region. agu fall meeting 2022, held in chicago. p 2. https://ui.adsabs.harvard.edu/abs/2022agufm.a34f..02i/abstract msm, 2022. soil physical properties and processes. minnesota stormwater manual. p 8. https://stormwater.pca.state.mn.us/index.php?title=soil_physical_properties_and_processes nbs, 2022. nigeria flood impact, recovery and mitigation assessment report 2022-2023. national bureau of statistics. p 2. www.nigerianstat.gov.ng/elibrary/read/1241417 umasankareswari t., dharshana v., saravanadevi k., dorothy r., sasilatha t., nguyen t.a., and rajendran s., 2022. soil moisture nanosensors. nanosensors for smart agriculture. p 2. https://doi.org/10.1016/b978-0-12-824554-5.00019-7 heddam s., 2021. new formulation for predicting soil moisture content using only soil temperature as predictor: multivariate adaptive regression splines versus random forest, multilayer perceptron neural network, m5 tree, and multiple linear regression. water engineering modeling and mathematic tools. science direct. p 1. https://doi.org/10.1016/b978-0-12-820644-7.00027-x okolotu g.i., and oluka s.i., 2021. shore reclamation for agricultural use, a combat to shoreline erosion. advance journal of science, engineering and technology. volume: 6; issue: 05. p 18. https://aspjournals.org/ajset/index.php/ajset/article/view/28 shweta upadhyay s., raghubanshi a.s., 2020. determinants of soil carbon dynamics in urban ecosystems. urban ecology (emerging patterns and social-ecological systems), p 302. science direct. www.sciencedirect.com/science/article/abs/pii/b9780128207307000161 american gardening resource, 2019. digging into the soil: a garden practicum, in cooperation of lower sugar river watershed association, p 4.https://lsrwa.org mailto:topacademicjournals@gmail.com https://doi.org/10.1016/b978-0-12-824554-5.00019-7 academic journal of science, engineering and technology vol. 10, issue 6; november-december 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset datta s., taghvaeian s., stivers j., 2018. understanding soil water content and thresholds for irrigation management. p 1. https://extension.okstate.edu/fact-sheets/understanding-soil-water-content-andthresholds-for-irrigation-management.html okolotu g.i., oluka s.i., and, eze p.c., 2017. determination of erosivity of enugu state. international journal of environment, agriculture and biotechnology (ijeab) vol-2, issue -1, p 72. http://dx.doi.org/10.22161/ijeab/2.1.11 okolotu g.i, eze p.c., and, eze c.n., 2017. determination of slope of enugu for erosion models. international journal of environment, agriculture and biotechnology (ijeab) volume 2. issue 4. p 2248. http://dx.doi.org/10.22161/ijeab/2.4.85 mailto:topacademicjournals@gmail.com http://dx.doi.org/10.22161/ijeab/2.1.11 academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset nigeria's struggle against human trafficking: a battle for national dignity amina ezeife department of history and international studies, kogi state university, anyigba, kogi state nigeria abstract: this study examines the historical context and implications of the british colonial administration's efforts to suppress the trans-atlantic slave trade in what later became nigeria. the suppression of this inhumane trade began with the british military expedition on lagos territory in 1861, leading to the declaration of the area as a british crown colony. the first ordinance specifically prohibiting slave dealing and internal slave trafficking within the crown colony of lagos was enacted in 1874. however, it wasn't until august 31, 1916, that a decisive decree was passed, liberating every slave in the southern provinces of nigeria. this decree also unequivocally forbade any recognition of the status of slavery by british or native courts in these regions. the british colonial administration's anti-slavery laws not only marked the end of slavery as a social institution in nigeria but also heralded a new era of revolutionary ideals, emphasizing liberty, freedom, and equality among the nigerian population under british colonial rule. keywords: british colonial administration, trans-atlantic slave trade, nigeria, anti-slavery laws, social institution, liberty, freedom, equality. introduction the suppression of trans-atlantic slave trade in what later became nigeria began with the british military expedition on lagos territory and the subsequent declaration of the area british crown colony in 1861. however, it was not until 1874 that the first ordinance was enacted prohibiting slave dealing and internal traffic in slaves within the crown colony of lagos (lugard, 1919). on august 31, 1916 the british colonial administration prohibited slavery in southern provinces by the enactment of a decree to that effect. by this decree “every slave in the southern provinces was liberated”. it followed that “no court, british or native, may in any way whatever recognize the status of slavery in the southern provinces of nigeria” (lugard, 1919). the british colonial administration’s anti-slavery laws marked the end of slavery as a social institution in nigeria. they also ushered in a modern era of revolutionary ideas of liberty, freedom and equality among nigerian people under the british colonial state. by 1960, when nigeria secured her independence from britain, slavery as a social institution or socio-cultural practice had virtually ceased to exist. indeed, it became illegal and vexatious even to raise the issue in reference to an individual or group. in 1980s, however, when nigeria’s economy witnessed serious decline as a result of oil glut, the country began to experience mass poverty manifested by increasing unemployment, soaring prices of essential goods and low wages. consequently, there was widespread misery and frustration among mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the populace especially the large number of unemployed youths who began to believe that their prospect of economic survival lay outside the shores of the country. this encouraged many youths to begin to emigrate from nigeria in large number and, in most cases, to europe, asia and america. the mass exodus of youths from nigeria and, indeed, other sub-saharan african and asian countries to the economically advanced nations of europe and america encouraged the emergence of syndicates who devised methods for enticing would-be trafficked persons. in the case of nigeria specifically, the syndicates developed very strong and dependable network for effective organization, recruitment and movement of would-be trafficked persons from their local communities to north africa across the perilous sahara desert. most nigerian victims of human trafficking pass through niger, mali, tunisia, morocco or libya en route to europe (ojugbana, 2015:28). by 1990s the large number of emigrants (victims of human trafficking from nigeria and other african countries and asia) roaming the streets of some european countries were considerable. nigeria was listed among the african countries with the highest number of women trafficked to europe for commercial sex business. according to otti (2011:16), about 50,000 nigerian women were trafficked to europe every year for prostitution. he stated that trafficking of women and children across local boarders in africa has been on increase despite counter-measures by government agencies and anti-trafficking organizations. as many of the trafficked persons were without valid traveling documents, they became source of great concern and embarrassment to their respective countries. many of them were said to have constituted social nuisance in their host countries, for example, the young prostitutes openly soliciting for male clients in the streets of italy and amsterdam (njoku, 2005). the situation created a new global problem involving the trafficking in human persons across national borders for sexual exploitation and other oppressive and dehumanizing purposes. the phenomenon was described as a form of “modern-day slavery”. the meaning of human trafficking in 1999 the united nations general assembly defined human trafficking as the illicit and clandestine movement of persons across national, international borders, largely from developing countries in transition with the end goal of forcing women, children into sexually or economically oppressive and exploitative situations for the profit of recruiters, traffickers, crime syndicates as well as all other illegal activities related to trafficking such as forced domestic labour (cited in adoba, 2004). also oloko cited in okpalakunne (2006) described human trafficking as the recruitment, transportation, transfer labour receipt of a person through deception, force, coercion to a strange place within or across borders for the purpose of retraining such a person in a situation of enslavement, servitude or debt bondage (cited in okpalakunne, 2006). thus, human trafficking involves carrying human beings particularly women, children and other able-bodied youths from one place to another, at times across national and international borders by the traffickers for the purpose of subjecting the trafficked persons to prostitution, drug peddling or child labour. some youths were also lured into various crimes such as armed robbery, fraud and membership of violent gangs etc. as they found themselves in foreign countries. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset human trafficking in nigeria although human trafficking has become a global problem, nevertheless, african countries (including nigeria) serve as major sources of trafficked persons. according to the report which the united nations children emergency fund (unicef) presented to the conference of african ministers in benin republic in 2004, human trafficking is prominent in 53 african countries. the report revealed that 89 percent of the 53 nations involved had been trafficking human beings to and from neighbouring countries, but an appreciable volume of the traffic flows to europe (see akaigwe, 2004; njoku, 2005). the african children were said to be “the biggest victims of the complex phenomenon, and are twice as likely to be trafficked as women”. some are engaged as child soldiers in war-torn african countries, while many others work as domestic servants, farm labourers or sold into prostitution. awake (june 22, 2002) observed that most ‘modern-day slaves’ are often women and children. the paper noted that they toil against their will either as child labourers or even prostitutes. for instance, the report on child labour released in 2008 showed that an estimated 284,000 child labourers existed in west africa and many of them worked in coca farms “on slave labour wages or for nothing in order to put chocolate into the mouths of consumers” (the punch, february 20, 2008). in nigeria specifically, human trafficking involving women and children has been going on in several locations and communities. the report on trafficking in persons, 2004 cited in maduagwu (2004) described nigeria as a source, transit and destination country for trafficked women and children. the report noted that nigerians were trafficked to europe, the middle east and other countries for purpose of forced labour, domestic servitude and sexual exploitation. it also described nigeria as a destination country for togolese, beninese, ghanaian and cameroonian children trafficked for forced labour (see maduagwu, 2004). a recent report on human trafficking and migration to europe shows that in 2014, 170, 100 arrived italy by sea, compared to 141, 484 migrants that were ferried through the mediterranean sea from libya in 2013. according to the report, the migrants had come from syria (42, 323), eritrea (34, 329), mali (9,908) nigeria (9,000), gambia (8, 691), somalia (5, 756) and some other nations (4,095). among the migrants, 64, 625 were said to have applied for asylum (ojugbana, 2015:29). in the case of nigeria, most of the migrants were victims of human trafficking hoodwinked by syndicates as a result of their desperation to travel to europe or asia for a better life. thus, human trafficking is a complex phenomenon of which many people are involved at both family and community levels, as well as at the border or international transactions. the guardian opinion (june 29, 2004) observed that nigeria is a well-known player in human trafficking. according to the paper, the country serves as” a base camp and transit channel for traffickers and their human commodity”. the paper also noted that inside the country and at border areas some locations are known to be target spots for operations. in a similar view, oloko cited in okpalakunne (2006) explained that child trafficking consists of both national and trans-national recruitment and movement of children for the purpose of providing cheap, manipulatable and exploitable labour for domestic and agricultural work, commercial sex work or prostitution, begging, unregulated industrial work and street trading. the south-east and south-south geo-political zones of nigeria are noted for active involvement in human trafficking. for instance, several thousands of children are known to have been trafficked from igbo land, akwa ibom and cross river states to lagos, benin republic, togo and gabon for the purpose of engaging mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset them in child labour, which is akin to child slavery. the high rate of child trafficking became a major source of concern to the akwa, ibom state government that it banned “all forms of trafficking in children from the state to other parts of the country to serve as house-helps or cheap labour of any form” in 2004. the government also threatened to “deal drastically with parents who persist and promote trafficking in children” (see solomon, 2004). the western part of the country is also involved in child trafficking for the purpose of using them as cheap labour for domestic work, agricultural production, including cocoa and rubber farms. nwakamma (2004) reported that asewele, a community in ondo state is a spot for child slavery. he stated that both males and females were sold at a price of about n25, 000.00 each across the border and there were always prospective buyers. he also noted that despite the efforts being made by the police and immigration officers, nigerian borders are still vulnerable as far as child trafficking is concerned. in benin city, capital of edo state, there were syndicates who specialized in recruiting and sponsoring young ladies to europe especially italy, amsterdam and belgium for prostitution. taire (2004) observed that it was since 2000 that the issue of nigerian women in general, and ladies from benin city and its environs in particular going to europe to work as commercial sex workers had become a real cause for concern. similarly, this day (may 3, 2004) in a story culled from economist stated that people-trafficking in benin-city was an organized and lucrative trade. the paper observed that it was riot possible to know how many ladies were shipped out each year, but that “every one in benin-city knows who has gone”. the paper noted that the girls were recruited by local sponsors “who pay up-front for transport, and the girls therefore start out with thousands of dollars in debt” by 2004, it was estimated that no fewer than 100,000 young nigerian women had been sold into sex slavery as prostitutes, servicing ‘top guns’ and ‘big boys’ in europe’s flourishing underground sex industry. according to an official of the national agency for the prohibition of trafficking in persons (naptip), alhaji mohammed babandede out of about 90,000 sex workers of nigerian origin in italy 50,000 of them were from edo state. this, according to aihaji babandede, represented 60 percent of prostitutes in that country (see njoku, 2005). sequel to this, the united states of america placed nigeria on her tier 2-watch list of countries involved in trafficking in persons. according to joann schneider, deputy director of the office to combat and monitor trafficking in persons, washington, nigeria did not comply with the minimum standards for the elimination of trafficking though united states recognized that nigeria was “making significant efforts to do so” (see emeozor, 2004). it was as a result of the menace of human trafficking in nigeria and its increasing damage to the nation’s image abroad that some anti-human trafficking organizations were formed by some patriotic individuals to stem the ugly tide. among these organizations the most influential, powerful and well focused was the women trafficking and child labour eradication foundation (wotclef) founded by mrs. amina titi abubakar, wife of former vice president of nigeria, alhaji atiku abubakar. wotclef initiated and sponsored the anti-human trafficking and child labour bill which was passed by the national assembly and subsequently signed into law by the former president, chief olusegun obasanjo on july 14, 2003 (njoku, 2005). the legislation (act) provided for the establishment of the national enforcement and administration to be known as national agency for the prohibition of trafficking in persons and other related matters (naptip). it gave mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the agency sweeping powers to initiate prosecution of barons or syndicates of the illicit trade. the naptip mission statement is the full commitment to the prevention of all forms of human degradation and exploitation. through the coordinated use of nation crime prevention and law enforcement resources, we are determined to stamp out human trafficking and to liberate and uplift the vulnerable especially women and children, from dehumanizing exploitative usage, as well as to ensure their rehabilitation and effective reintegration into the society (cited in adoba, 2004). in 2005 the naptip act was amended which criminalized the keeping of brothels and the use of children as domestic house helps. the properties of the offenders of this amended act have become targets for seizure by government (olayinka, 2011). moreover, the federal government has encouraged naptip to establish a national investigation task force (nitf). the nitf has been upgraded to effective coordinating offices in many states of the federation particularly in states with worst human trafficking problems. naptip has also established shelters where victims of human trafficking are taken care of during rescue and rehabilitation period. those shelters exist in zonal offices located in lagos, kano, benin, enugu, uyo, sokoto and maiduguri (olayinka, 2011). besides, naptip was said to be increasingly making use of the police, immigration service and traditional rulers in its fight against human trafficking in nigeria. it was also said to have successfully investigated many cases and had also succeeded in securing the convictions of many syndicates involved in human trafficking in the country. the naptip was also said to be increasingly collaborating with some national and international agencies in its fight against human trafficking. for instance, the naptip was said to be collaborating with international organization for migration (iom), spanish police, the italian anti-mafia bureau and benin republic police etc. the collaboration with these agencies was said to have resulted in the arrests and trial of some syndicates involved in human trafficking and the formal repatriation of some victims of the illicit trade, okumephana (2004) stated that the collaboration between naptip and other agencies had resulted in the arrests of syndicates involved in 13 different cases of which four had been charged to court by december, 2004. however, the executive secretary of naptip, mr. simon chudi egede has revealed that his agency has secured more than 100 convictions with many of them serving various jail terms ranging from two to 24 years in prison (see olayinka, 2011). above all, naptip was said to have been committed towards the rehabilitation of victims of human trafficking. according to the executive secretary of naptip, mr. simon chuzi egede between 2009 and 2010 the agency spent about n50 million on over 100 victims empowering them with trade equipment and seed money to enable them start their own businesses. he stated that so far about 4,934 victims had passed through the agency with 1,884 recorded between 2009 and 2010. mr. egede further stated that out of this figure 526 victims had been rehabilitated either by returning to school or assisted to acquire vocational skills (see olayinka, 2011). it should be noted that the naptip’s figure on victims of human trafficking rescued between 2009 and 2010 shows that the ‘modern-day slavery’ has not in any way abated. this is particularly when considered in the light of the number of victims rescued by the agency which might probably have been a small percentage of the entire persons trafficked within the period. for instance, daily independent editorial (february 25, 2011) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset painted a grimmer picture of how “thousands of mostly unskilled nigerian youths battle their way through the harsh, cold weather of the sahara desert to southern europe” the paper noted that for many of these youths “it was the devil’s alternative choice”. that is, according to the paper, either “to remain un-catered for by the emergent avaricious political class that has continued to channel state resources for personal aggrandizement or to risk their lives outside nigeria as factory hands, doing menial jobs or plain prostitution”. the paper noted that many nigerian youths “took the plunge and died in the process”, while “some of those who survived and succeeded in their chosen careers are now smiling to the bank and even sending valuable money home” (daily independent editorial, february 25, 2011). similarly, the national anti-human trafficking campaign report released by its national co-ordiantor, richard ossai shows that human trafficking between nigeria and the world “is taking a worse dimension”. ossai in his report stated that “besides slave work abuse, the victims are losing their vital parts for a paltry $150 in return for the permanent damage done to them”. he, however, acknowledged that the federal government in collaboration with various organizations has done more than any other african country in the fight against human trafficking, a feat he noted has resulted in nigeria moving out of the status of countries with worst cases of trafficking. but the scourge of human trafficking still persists in the country which he (ossai) described as “a dehumanizing act” (see nigerian pilot, january 20, 2011). the major reasons for the persistence of the ugly phenomenon of human trafficking in nigeria include pervasive poverty in the society especially at the family level; the frightening problem of unemployment among the populace particularly the youths, and ignorance of the prospective victims of human trafficking about their fate in foreign countries. some other reasons include bad leadership that has failed to improve the welfare of the citizens thereby resulting in mass disillusionment and the urge by many citizens to leave the country in search for better living conditions in other countries; the abuse of traditional method of fostering children and get-rich-quick syndrome in contemporary nigerian society. there is also the pressures of urban migration which have stretched the demands for house helps and, in turn, induced the internal trafficking of young boys and girls conscripted sometimes into near slave labour (the guardian editorial, june 29, 2004). moreover, there is the problem of the existence of powerful and influential syndicates within and outside nigeria that coordinate and finance the despicable business, and the lure of huge profit that accrue to them annually from it. for instance, it was revealed by mrs. g.b. idiodi, the executive director of light bearers organization (lbo) that “the perpetrators of human trafficking are believed to be raking in between $7 billion to $10 billion dollars annually” (see nzama, 2004). besides, there is the alleged complicity of some security personnel in trafficking of persons especially within the borders (see emeozor, 2004). thus, although some officials of naptip claim that nigeria is winning the war against human trafficking, nevertheless, the sordid business still persists (see godwin, 2014:15). for instance, ojugbana (2015:29) reported that between january, and march 3, 2015, 463 nigerians were among 7,882 migrants that arrived italy by sea from libya. effects of human trafficking on nigeria’s image the concept of national image subsumes a mental picture in which a nation-state portrays or projects about herself in her relations with other nation-states in international system. it is a significant factor or an essential element for the perception and assessment of national character. morgenthau (1949) described national character as those “fundamental intellectual and moral traits which reveal themselves on all levels of thought mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and action and which give each nation its unmistakable distinctiveness”. it is in recognition of the need to portray good national image among comity of nations that nigeria established naptip and as well collaborates with various organizations in the fight against the scourge of human trafficking. despite these efforts, however, the incidence of human trafficking persists and has continued to create negative effects on the country’s image in the following ways: 1. human trafficking portrays nigeria in a bad light. it creates erroneous impression that the country is incapable of providing for her citizens especially in terms of employment and social welfare, hence the exodus of her able-bodied youths to foreign countries. 2. it dents the image of the country as many young prostitutes of nigerian origin are allegedly often spotted in sex parlours and streets of some european countries (italy, holland and belgium etc) soliciting for male clients. an official of the naptip, alhaji mohammed babandede revealed in 2004 that there were no fewer than 100,000 nigerian women sold into sex slavery as prostitutes in europe (see njoku, 2005). 3. human trafficking involving nigerian ladies gives the ugly impression that nigerian citizens help to sustain the underground sex industry in europe involving young teenagers. 4. the human trafficking conundrum erroneously portrays nigeria as a country in throes of political and economic crises. this is despite the fact that the country conducted free, fair, credible and peaceful general elections recently, and is making efforts to improve socioeconomic conditions of its citizens. human trafficking, therefore, creates wrong impression of the image of the country. 5. it frustrates the efforts of the government towards the achievement of millennium development goals (mdgs) particularly education for all. many of the victims of child trafficking are deprived of the opportunity to acquire formal education. besides, ezinma (2010) reported that over 12 million nigerian children are in the bondage of child labour and more are at risk of joining the child labour condition. he stated in his report that it is quite sad that many years after the goal of international programme on the elimination of child labour work (ipec) was launched, the prevention and elimination of worst form of child labour (wfcl) is still a mirage in nigeria. this casts doubts on the commitment of the country towards eliminating child labour which is akin to child slavery. 6. brain drain which is another dimension of ‘human trafficking’ deprives the country highskilled manpower needed for rapid national development. ibekwe (2010) summarized the negative effects of brain drain on developing countries, including nigeria as follows: brain drain in developing countries has financial, institutional and social costs: little return from their investments in higher education; increasing dependency on foreign expertise due to dwindling professional sector; diminishing ability of several developing countries to offer basic health care services to their subjects; widening gap in science and technology between the richer and poor countries; crumbling middle class population; failing tax system and disappearance of jobs and society (ibekwe, 2010). with particular reference to nigeria, professors wilma meus and david sanders, both of the university of the western cape’s school of public health, south africa stated in their research report that nigeria has incurred loss of $420 million (n53.34 billion) through the loss of 21,000 doctors to the united states of america. meus and sanders stated that conservative estimates showed that the united states has saved at least $3.86 million mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (n490.2 million) in training fees by employing doctors from nigeria (see bagshaw, 2003). similarly, thousands of medical experts of nigerian origin reside and work in united kingdom. on the other hand, nigeria’s health care and education sectors have “been in deplorable state partly due to inadequate number of experts as a result of the effect of brain drain.” in the case of health sector, for instance, the report on the progress of the millennium development goals (mdgs) as documented by anuforo (2010) shows that nigeria really still does not have the kind of public health system that the country…. needs. the life expectancy in nigeria is about 55 years, while in other middle income countries it is about 70, and higher income countries about 80 plus. nigeria is just not achieving the health and maternal survival of the child befitting a country of its stature (anuforo, 2010). it should be noted that nigerians in diaspora were said to be over 20 million contributing greatly to the development of their various countries of residence (nwanunobi, 2006). 7. human trafficking exposes some nigerian citizens to all forms of inhuman treatment in foreign countries. these include physical assault, rape, detention and in some extreme cases execution. many nigerians are also known to be languishing in prisons in some countries of the world due to the misadventure associated with human trafficking. 8. it gives rise to frequent deportation of nigerian citizens from foreign countries with its attendant diplomatic implications. the former head of nigeria immigration service (nis), trafficking unit, miss nnenna mbagwu revealed that a total of 2,562 nigerian girls were deported from europe in 2002. she also stated that 189 minors who were being ‘towed out’ of the country ostensibly for child slavery were intercepted in the same year. (daily champion, january 30, 2003). 9. human trafficking exposes nigerian youths to the danger of being used as ‘guinea pigs’ for scientific and medical researches in foreign countries. the national coordinator of the national anti-human trafficking campaign (nahtc), mr. richard osai lamented that human trafficking between nigeria and the world “is taking worse dimension”. he stated that “besides slave work abuse, the victims are losing their vital parts for a paltry $150 in return for the permanent damage done to them” (see nigerian pilot, january 20, 2011). this is not only an act of indignity against such victims, but also portrays them as subhumans without protective rights. 10. it impugns on nigeria’s national character. it was partly as a result of the bad image which human trafficking paints about the country that the federal government resolved to embark on re-branding nigeria project. conclusion human trafficking is a form of ‘modern-day slavery’ which involves the movement of thousands of nigerian women and children mainly through land routes to some north and west african countries with the ultimate aim of taking them to europe for slave labour and prostitution. the escalation of the incidence of human trafficking in nigeria began in 1980s as a result of decline in nigeria’s economy which gave rise to pervasive poverty at family level; frightening unemployment; deterioration of social infrastructure; low wages, soaring prices of goods and consequent social misery among the populace. this situation provoked the urge to mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset immigrate to foreign countries by many nigerians to seek for better life and favourable economic opportunities. some nigerian citizens who embarked on the desperate journey did not reach their destinations due to associated hazards, while many of those who got to their destinations found themselves engaging in precarious jobs akin to slave labour, prostitution or crime. this created bad image for the country and necessitated the establishment of naptip, and collaboration with some international organizations to stem the tide. the scourge of human trafficking still persists in the country despite federal government’s concerted actions. indeed, it has become part of the global problem of illegal migration involving hundreds of thousands of people mainly from africa and middle east, which presently threaten the social stability of europe. references adoba, i. (2004) “a close look into nigeria’s illegal export”, this day, wednesday, june 16, pp 38 41. akaigwe, m. (2004) “unicef raises fresh alarm over child trafficking,” saturday champion, may 8, p35. anuforo, e. (2010) “mdgs: nigeria struts, frets on the road to 2015”, the guardian, friday, august 6, pp 12-13. awake (2002) “slavery: the plague persists”, awake, june 22, p3. bagshaw, n. (2003) “emigrant doctors: nigeria loses n53.34 billion to us”, daily independent, tuesday, september 16, pb8. daily independent editorial, (2011) “maximizing remittances from the diaspora”, daily independent, friday, february 25, p31. “efforts too small to curb child labour on cocoa farms” the punch, wednesday, february 20, 2008, p39. emeozor, e. (2004) “trafficking in persons: nigeria remains in us tier 2watch list”, daily sun, monday, july 26, p11. ezinma, b. (2010) “child labour: dilemma of nigerian government” , saturday in dependent, september 11, p11. global human trafficking assumes a worst dimension -nahtc” nigerian pilot, thursday, january 20, 2011, p7. godwin, i. (2014), “nigeria winning war against human traffickingnaptip”, daily sun, friday september 12, p19. ibekwe, m. (2010), “can brain drain benefit everyone?” the punch, october 26, p12. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.8, issue 4; july august 2023; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset lugard, f.d. (1919) “political memoranda”, london: waterlow and sons ltd, pp 217-220. maduagwu, c. (2004) “human trafficking: nigeria’s efforts, not good enough”, daily champion, thursday, july 29, p34. makinde, f. (2004) “human trafficking: pathetic story of sylva,” the punch, friday, september 24, p14. morgenthau, h.j. (1949) “politics among nations”, new york: alfred a. knopf, mc, p96. njoku a. 0. (2005) contemporary public issues in social studies education in nigeria, enugu: redeemed printing and publishing co, pp 185 — 208. nwanunobi, t. (2006) “nigeria marks first diaspora day”, leadership, july 27, p8. nzama, b. (2004) “child traffickers earn $10 billion annually-ngo,” daily sun, wednesday, december 8, p7. ojugbana, v. (2015) “between allure of better life and death at mediterranean sea”, the guardian, friday, may 22, pp 2829. okpalakunne, n. (2006) “the evils of human trafficking, child labour”, daily champion, thursday, april. 6, p15. okumephana, c. (2005) “u.s. lauds nigeria’s fight against human trafficking” , the guardian, friday, january 28, p7. olayinka, c. (2011), “victims of human trafficking get n50 million employment fund” , the guardian, tuesday, february 1, p43. otti, s. (2011) “how nigerian girls are forced into prostitution in mali”, daily sun, tuesday, november 29, p16. solomon, t. (2004) “akwa ibom bans child trafficking”, vanguard, june 1, p7. the guardian editorial, (2004) “the scandal of child trafficking”, the guardian, tuesday, june 29, p22. this day (2004) “people trafficking: nigeria’s other export”, thisday, monday, may 3, bp. “2,562 nigerian girls deported from europe”, daily champion, thursday, january 30, 2003, p9. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset optimizing production costs: a review of modern tools and techniques in manufacturing 1*ezeaku i i, 2onuoha g.o, 3nwadinobi c.p and 4opara v u 1,3department of mechanical engineering, faculty of engineering, abia state university, uturu, nigeria. 2,4department of mechanical engineering, school of engineering and engineering technology, federal university of technology, owerri, nigeria. *corresponding author’s e-mail: ezeakuinnocentmnse@gmail.com. doi: https://doi.org/10.5281/zenodo.15622483 abstract: finding efficient ways to maximize production expenses has become even more vital given the rising complexity and competitiveness of world manufacturing. this study examines the most recent techniques and instruments employed to reduce costs without compromising operational efficiency or product quality. although conventional techniques like lean manufacturing, six sigma, and just-in-time (jit) approaches remain crucial, new developments in digital technology are altering the cost optimization method used. real-time observation, predictive maintenance, and smart decision-making in production systems are made possible by new technologies including big data analytics, the internet of things (iot), machine learning, and digital twins. moreover, sophisticated cost models are increasingly generated and resource allocation is improved using computational intelligence techniques such as neural networks and genetic algorithms. this study provides a comprehensive review of both technology-based and conventional cost optimizing methods, evaluating their applicability for various sectors, effectiveness, and implementation difficulties. the review emphasizes significant trends and knowledge gaps by combining recent study with business practices, therefore offering a road map for future developments in cost-effective manufacturing. particularly in the framework of industry 4.0, the findings seek to help researchers, decision-makers, and practitioners select and apply suitable instruments for specific manufacturing environments and smart manufacturing systems. keywords: optimization, production costs, cost-efficient manufacturing, decision-makers, tools and techniques introduction in today's fiercely competitive industrial environment, manufacturers consider reducing production costs as a vital focus in order to achieve profitability, enhance operational efficiency, and boost market presence. the rising costs of raw materials, increased energy prices, higher labor costs, and the growing need for personalized products have put more pressure on manufacturers to create effective strategies for cost reduction (gunasekaran et al., 2001). consequently, companies are utilizing a variety of contemporary tools and methods aimed at cutting waste, improving how resources are used, and streamlining processes while still ensuring product quality and satisfying mailto:topacademicjournals@gmail.com mailto:ezeakuinnocentmnse@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset customers. modern production cost reduction includes both conventional methods like lean manufacturing, six sigma, and just-in-time (jit) systems, along with innovative technologies such as machine learning, big data analysis, digital twins, and the internet of things (iot) (womack & jones, 2003; lee et al. , 2015). these resources offer realtime tracking and predictive insights that help manufacturers make knowledgeable choices and manage production resources effectively. in particular, techniques in computational intelligence (ci) have gained popularity for their potential to model intricate manufacturing systems and facilitate economical decision-making through smart automation (jain et al., 2018). even with a rising number of tools available, choosing the right and most effective techniques suitable for particular manufacturing settings is still difficult because of variations in production size, complexity, and levels of technology adoption. hence, conducting a thorough examination of modern cost optimization methods and tools is crucial to grasp their functions, constraints, and implementation difficulties. this analysis intends to provide a detailed summary of present practices, shine a light on upcoming trends, and pinpoint areas lacking in current literature, thus offering helpful insights for both researchers and industry professionals aiming to enhance production costs in the age of smart manufacturing. inventory management in the present competitive business world, organizations need to manage inventories with efficient policies especially when the distribution network is dealing with deteriorating inventories ( ahlaqqach et al.,2020). sometimes due to high demand or season or the deteriorating nature of inventories, manufacturers increase their production and therefore need rented warehouse (rw) facility to manage a large number of inventories (chang et al., 2020). once the organization rents an extra facility to keep the extra number of inventories, the problem that they face is which inventories should be used first for minimum cost and minimum deterioration of inventories (chang et al., 2020). the green supply chain is also a need as carbon factor is increasing in the environment and business firms are also responsible for carbon generation by manufacturing, transportation, warehousing, etc.; therefore, it needs to be controlled by effective policies. government and policymakers initiate policies such as carbon tax, carbon cap, and trade and offset policies to control carbon factors (ahlaqqach et al., 2020). the deterioration process is a natural process that cannot be stopped but it can be minimized if deteriorating nature inventories are managed properly. inspection is one such policy that is effective for deteriorating nature inventories. according to bai et al., (2016), deteriorated inventories are removed from the supply chain at the initial stage, then it will not deteriorate other inventories by contact and the decaying process can be minimized to some extent. in the same way, separated deteriorated inventories can be utilized to earn revenue and also solve the problem of the disposal of decaying inventories. an inspection policy helps to reduce carbon emissions and helps to turn a supply chain into a green supply chain. deterioration is a natural activity that must happen with decaying types of inventories (pal et al., 2015). it cannot be stopped but it can be minimized with some tools. many researchers, policymakers, and organizations have given distinct policies, tools, and management areas that could be profitable for the firms to mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset handle such inventories. many works have been conducted in this area with different policies. pal et al., (2015), in their work defined a prepayment policy for retailers as a financial arrangement where customers are required to make a payment in advance before receiving goods or services. this policy is often used to manage credit risk, ensure cash flow, and reduce the risk of non-payment. retailers might implement prepayment policies for various reasons, such as when dealing with new or untrusted customers, high-value products, or customized orders. it can also be used as a way to secure commitments from customers and manage inventory more effectively. bai et al., (2016) is of the opinion that inspection policy for deteriorating inventories involves setting guidelines for the inspection, disposal, or handling of items that are prone to deterioration, spoilage, or obsolescence. this is particularly relevant for perishable goods, products with expiration dates, or items that lose value over time. implementing an inspection policy can help reduce losses from holding inventory that is no longer usable or saleable due to deterioration. muriana, (2016) stated that the actual behavior of the distribution network after applying an inspection policy can vary based on factors such as the nature of the products, the effectiveness of the policy implementation, the accuracy of demand forecasts, and the overall distribution structure. after applying an inspection policy for deteriorating inventories in a supply chain, several behaviors and outcomes may occur. the implementation of an inspection policy allows for more rigorous control over the quality and condition of inventory items. this helps to identify deteriorated items early enough and this prevents their inclusion in sales and reducing customer dissatisfaction (bai et al., 2016). also by identifying and disposing of deteriorating items promptly, the supply chain can minimize losses associated with holding inventory that can no longer be sold. the insights gained from the inspection policy can inform better demand forecasting and ordering decisions. this can lead to optimized inventory replenishment and reduced chances of overstocking items that might deteriorate (panda and modak, 2017). avoiding the sale of deteriorated items can enhance customer satisfaction and maintain the retailer's reputation for providing quality products. also preventing the sale of deteriorated items can save costs related to customer complaints, returns, and refunds. data collected through the inspection policy can be used to fine-tune inventory management strategies, including reorder points, safety stock levels, and replenishment schedules (jing and mu, 2019). according to pand and modak, (2017), implementing an inspection policy may require adjustments to processes and workflows to accommodate the identification, segregation, and disposal of deteriorating items. khakzad and gholamian, (2020) studied the prepayment policy for the retailer and the behaviour of distribution network after applying an inspection policy for deteriorating inventories. they were able to optimize the cost associated with the finished goods inventory. halim et al., (2021) discussed a production opening inventory model for deteriorating items under overtime concept with price and available inventory focused demand. according to them, in the present combative and developing business world, it is a very challenging and tough task to manage decay type inventories without any loss. moreover, a manufacturer may find it very costly to own a more spacious and well-established warehouse. in this situation, if the amount of manufactured inventories is more than the holding susceptibility of the owner warehouse (ow), the manufacturer will require a rented warehouse (rw) (halim et al., 2021). sometimes manufacturers feel the need for extra mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset production due to higher demand of inventories in the market and when manufacturer are dealing with deteriorating types of inventories, it necessary that production size be larger than demand of the market (halim et al., 2021). sometimes some seasonable products are manufactured before the season so as to fulfil market demand without delay. some organizations manufacture inventories in rw and keep them in ow. therefore, after placing them in rw, the next important policy is how to utilize these inventories, which means determining which inventories must be used first for maximum profit. though it somewhat depends on factors such as the nature of the inventories and the rent of rw. distinct supply chains adopt different policies but there are some policies that are established by policy makers and researchers. as well, these are also used by the market. organizations are required to choose a dispatching policy that fits their supply chain and that can fulfil customer demand with minimum cost, less deterioration of inventory, and utilization of whole inventory without any loss (maihami et al., 2019). for this, manufacturers should have enough knowledge about dispatching policies that suit their supply chain and provide maximum profit. some of these policies are: (a) lifo (last in first out) policy. this policy works with the concept that rw inventories should be used first as it reduces extra rent, which leads to minimum cost because it is an extra cost burden (chakraborty et al., 2018). (b) fifo (first in first out). this policy works with the concept that ow inventories should be used first as it reduces the deterioration rate, because the inventory that comes first is manufactured first so it will become deteriorated first, hence, when used first, it reduces the deterioration cost (yu, 2019). there is one more concept behind this policy that some rws provide better storage policies compared to ow which reduces deterioration. in rw, inventories can be kept fresh for a longer period and it minimizes deterioration cost and indirectly maximizes profit instead of greater cost of rw. in the fifo policy, inventories that are kept first, must be utilized first. there are some rws that charge less with a good quality of storage facilities that reduce deterioration so that it is more profitable for firms to use ow inventories. many organizations work with this policy to make sure better originality of the stored inventory (xu et al., 2017). (c) mfifo (mix first in first out) policy. this works with the concept of the fifo policy but with some modifications. in this policy, deteriorated inventories are replaced with rw so rw inventories are also simultaneously utilized. xu et al., (2017) worked on this policy with a constant demand rate. (d) mlifo (mix last in first out) dispatching policy. this policy works upon the lifo policy with some modification. in this policy rw inventories are used first. inventories from rw are sent to ow and then to the market. some of the manufactures manufacture inventories in rw and then place them in owner warehouse. notably, xu et al., (2017) worked with this policy on deteriorating inventories. they also considered all the above policies and compared them using mathematical modeling in each case. (e) mixed fifo and lifo policy. in this policy, both inventories are utilized simultaneously depending on the customer’s demand (minner and transchel, 2017). in this policy, ow inventories are utilized first but some fraction of inventories is replaced from rw. thus, under this policy, both warehouses are used simultaneously and inventories are finished at the same time. green supply chain means “integrate environmental thinking into mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset supply chain”. at the present time world business manufacturers, policymakers, and researchers are attracted to the problem of carbon emission during supply chain (mishra et al., 2020). if the supply chain is dealing with deteriorating types of inventories then this problem requires more involvement. policymakers and governments established a few policies to solve these problems such as carbon tax, cap and tax, offset policy and trade and cap etc. huang. and fang (2019) established a model considering the carbon emission regulation policy by using the game theory approach. yu et al., 2020) studied and established a model with preservation technology for carbon emission considering demand as the function of stock and price. according to them, it was difficult to manage these inventories at a low cost but if these inventories deal with some special policies, then it is profitable. inspection during supply chain to remove deteriorating inventories is one such tool that helps. inspection policy is a kind of tool that converts a normal supply chain into a green supply chain. if during each cycle the inspection process is adopted, then these inventories can be separated at the initial stage (mishra et al., 2020). this will help firms in two ways; one is that deteriorating inventories will not deteriorate other fresh inventories and the rate of decay can be minimized. the second is, if these deteriorating inventories are separated initially then it can be utilized for any purpose which helps to generate revenue. inspection policy also helps in reducing emission (yu et al., 2020). the separated products can be used for any other purpose based on the product or it can be sold as a product in the market at a low price so that it solves the disposal problem and reduces emissions. thus, with this policy, the supply chain becomes a green supply chain. simulation and optimization models simulation optimization (so) is simply refers as the optimization of an objective function subject to constraints, where both can be evaluated through stochastic simulation (satyajith et al., 2016). simulation optimization involves the search for those specific settings of the input parameters to a stochastic simulation such that a target objective, the function of the simulation output, is minimized. simulation and optimization models are valuable tools used in cost optimization in manufacturing. these models enable manufacturers to analyze complex systems, simulate various scenarios, and identify optimal solutions for cost reduction and operational improvement. simulation models replicate real-world processes using mathematical and statistical techniques (satyajith et al., 2016). they simulate the behavior of a manufacturing system by capturing the interactions among various variables, such as resources, activities, and constraints. simulation models can be used to assess the impact of different factors on costs, identify bottlenecks, and evaluate the effectiveness of potential cost optimization strategies. key characteristics of simulation models are outlined by andradottir (2006) as: 1. input variables: simulation models incorporate input variables such as production volumes, resource availability, demand patterns, and process parameters. ii. system representation: the model represents the manufacturing system's structure and processes, including production lines, workstations, material flows, and scheduling rules. iii. replication and iteration: simulation models are often run multiple times to generate statistical output and assess system performance under different scenarios. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset iv. analysis and optimization: simulation models enable the analysis of cost-related metrics, such as production costs, cycle times, inventory levels, and resource utilization. they can also be used to optimize system performance by identifying improvement opportunities and testing different cost-saving strategies. optimization models form a significant area of research in various disciplines, including mathematics, operations research, engineering, and computer science. these models aim to find the best possible solution for a given problem by optimizing certain objective functions and subject to specific constraints (deng and ferris 2007). one widely studied category of optimization models is linear programming (lp), which involves linear relationships between variables and constraints. the simplex algorithm, proposed by george dantzig in 1947, is a fundamental method used to solve lp problems (dolan and more 2012). nonlinear programming (nlp) extends optimization to handle non-linear objective functions and constraints. nlp models are commonly solved using techniques such as gradient-based methods, interior-point methods, or evolutionary algorithms. integer programming (ip) deals with optimization problems where the decision variables must take integer values. these models are often more challenging to solve compared to linear programming. additionally, there are specialized optimization models such as network optimization, stochastic optimization, dynamic programming, and convex optimization, each with their own specific techniques and applications. optimization models use mathematical algorithms and techniques to determine the best allocation of resources and optimize decision-making (dolan and more 2012). these models aim to find optimal solutions that minimize costs, maximize efficiency, or achieve other desired objectives. optimization models can be used to address various cost optimization problems in manufacturing, including production planning, scheduling, capacity allocation, inventory management, and supply chain optimization. optimization models define an objective function that quantifies the goal to be achieved, such as minimizing costs or maximizing profit. it also has decision variables which represent the decision options available, such as production quantities, resource allocations, or inventory levels. optimization models incorporate constraints that reflect the limitations and requirements of the manufacturing system, such as capacity constraints, demand constraints, or resource availability constraints. optimization models employ mathematical programming techniques, such as linear programming, integer programming, or dynamic programming, to find the optimal solution. it can be used to perform sensitivity analysis, which helps understand the impact of changes in input parameters on the optimal solution and cost outcomes (wang and pasupathy 2012). simulation and optimization models offer several benefits for cost optimization in manufacturing. these models help identify cost-saving opportunities, optimize resource allocation, and streamline processes, leading to overall cost reduction. optimization models optimize resource allocation, production planning, and scheduling to minimize costs and maximize operational efficiency. simulation and optimization models can be integrated with other cost optimization techniques, such as activitybased costing, lean manufacturing, or six sigma, to provide a comprehensive approach to cost optimization. for example, simulation models can evaluate the impact of lean initiatives or six sigma projects on costs and process mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset performance (wang, 2012). simulation and optimization models are powerful tools in cost optimization. they enable manufacturers to analyze complex systems, simulate scenarios, and identify optimal solutions for cost reduction, process improvement, and resource optimization. by leveraging these models, organizations can make data-driven decisions to enhance their cost competitiveness and operational efficiency. fu et al., (2011) provides a comprehensive survey of the field and its scope in solving manufacturing cost problems. the paper listed different ways in which optimization and simulation interact and provides a very basic simulation output analysis and convergence theory for simulation optimization. hong and nelson (2009) classify simulation optimization problems into those with a finite number of solutions, continuous decision variables and discrete variables that are integer-ordered in cost problems. birge and louveaux (2011) maintained that simulation optimization, like stochastic programming attempts to optimize under uncertainty. however, stochastic programming differs in that it makes heavy use of the model structure itself. derivative-free optimization (dfo) is sometimes referred to as black-box optimization method. output variability is the key factor that distinguishes so from dpo. as explained by conn et al., (2009), some dpo algorithm under certain assumptions, expect rates that are closer to linear than quadratic and therefore early termination may be suitable. policy gradient methods (peters et al., 2013) are a subfield of reinforcement learning, where the set of all possible sequences of actions make up the policy space which is estimated and a gradient ascent-type method is then used to move to a local optimum. discrete event simulations have been successfully used to model many real-world systems such as operations managements, queues and networks. the occurrence of events is modeled using probabilistic distributions in modelling the randomness (peters et al., 2013). cost optimization tools and techniques in manufacturing cost optimization is a very important aspect of manufacturing operations (chang. et al., 2020). the significance is presented in the following ways: it helps to improve profitability, competitive advantage, enhanced efficiency, sustainable operations, better decision making and adaptability of market changes (zeng et al., 2020). zeng et al., (2020) further explained thus: (i) improved profitability: cost optimization directly impacts a company's profitability. by identifying and implementing measures to reduce production costs, companies can increase their profit margins and financial stability. this is especially crucial in industries with tight profit margins or intense competition. (ii) competitive advantage: in today's global marketplace, companies face intense competition. implementing cost optimization strategies can provide a competitive edge by allowing companies to offer products at more competitive prices. this can help attract more customers and increase market share. (iii) enhanced efficiency: cost optimization in manufacturing operations often involves streamlining processes, reducing waste, and improving efficiency. by identifying and eliminating inefficiencies, companies can improve production cycle times, reduce lead times, and enhance overall operational performance. (iv) sustainable operations: cost optimization often involves reducing resource consumption, waste generation, and environmental impact. by implementing sustainable practices, companies can align their operations with environmental regulations and customer expectations, leading to improved brand reputation and customer loyalty. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (v) better decision-making: cost optimization requires a comprehensive understanding of production costs and factors influencing them. by analyzing cost data and implementing computational intelligence techniques, companies can gain insights that help in informed decision-making. this can involve identifying cost drivers, optimizing supply chain operations, or evaluating the cost-effectiveness of different manufacturing processes. (vi) adaptability to market changes: manufacturing companies must be agile and adaptable to changing market conditions, including fluctuating raw material costs, market demand shifts, or economic uncertainties. cost optimization strategies enable companies to quickly respond to market changes by adjusting production processes, sourcing strategies, or pricing structures. cost optimization in manufacturing operations is essential for improving profitability, competitiveness, operational efficiency, and sustainability. it allows companies to optimize their resources, enhance decision-making capabilities, and align their operations with market demands, leading to longterm success in the manufacturing industry (mohammadi et al., 2015). 1. activity-based costing (abc) activity-based costing (abc) is a cost optimization technique that provides a more accurate and detailed understanding of costs by tracing them to specific activities within an organization. it is a valuable tool for identifying cost drivers, allocating resources effectively, and making informed decisions regarding product pricing, process improvements, and resource utilization (ittner and larcker 2011). activity-based costing (abc) emerged as a response to the limitations of traditional cost allocation methods, such as the volume-based allocation used in traditional costing systems. abc recognizes that activities, rather than simple volume metrics, drive costs. it allocates costs based on the activities that consume resources and cause costs to be incurred. ittner and larcker (2011) argued that methodology of abc involves the following steps: a. identifying activities: activities are the fundamental actions or processes that occur within an organization, contributing to the creation of a product or service. b. assigning costs to activities: direct and indirect costs are assigned to each activity based on their consumption. c. determining cost drivers: cost drivers are the factors that influence the frequency or intensity of an activity. they provide a basis for allocating costs to cost objects (e.g., products, services, and customers) based on their utilization of activities. d. allocating costs to cost objects: costs are allocated to cost objects using cost drivers and activity consumption data. benefits of activity-based costing: enhanced cost accuracy: abc provides a more accurate understanding of costs by attributing them to specific activities, enabling better cost control and cost reduction decisions (ittner and larcker 2011). abc highlights the relationship between activities and costs, making it easier to identify areas of excessive costs or inefficiencies. ittner and larcker (2011) in their work, allocate resources more effectively and prioritize activities based on their impact on costs and performance of a manufacturing operations. they applied abc facilitates in analysis of profitability at the product, customer, and market segment level, helping organizations focus on high-value products or customers which provides valuable cost information for decision-making, such as pricing decisions, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset product mix optimization, process improvement initiatives, and outsourcing evaluations (gunasekaran and ngai 2004). implementing abc requires significant effort in collecting accurate and reliable data on activity costs and their drivers. it can be challenging to obtain data from various sources and departments within the organization. implementing abc can be resource-intensive, requiring investments in technology, training, and data collection systems. the initial costs of implementing abc may deter some organizations from adopting this approach (ittner and larcker 2011). subjectivity in cost driver selection: choosing appropriate cost drivers involve subjective judgments and incorrect driver selection can lead to distorted cost allocations. implementing abc may face resistance from employees who are accustomed to traditional costing methods. proper change in management and communication strategies is necessary to overcome this resistance (gunasekaran and ngai 2004). integration with other techniques: abc can be effectively integrated with other cost optimization techniques and tools to enhance decision-making and improve cost management. for example, abc data can be integrated with simulation and optimization models to identify cost-efficient process configurations and resource allocations. activity-based costing is a powerful cost optimization technique that provides organizations with a detailed understanding of costs and their drivers (gunasekaran and ngai 2004). by allocating costs based on activities, abc enables informed decisionmaking, better resource allocation, and improved profitability. however, implementing abc requires careful planning, data collection, and consideration of organizational dynamics to overcome challenges and leverage its benefits effectively. target costing target costing is a cost optimization technique that focuses on setting cost targets during the product design phase (cooper and slagmulder 2008). it is a proactive approach that aims to achieve desired profitability by considering customer requirements, competitor analysis, and market dynamics. target costing involves a systematic process of cost planning, cost management, and value engineering throughout the product lifecycle. the primary objective of target costing is to determine the target cost for a product or service that will allow the organization to achieve its desired profitability while considering market conditions and customer expectations. target costing provides understanding of customer needs, preferences, and price expectations through market research and customer feedback. target costing enables setting a target price based on the market analysis, considering factors such as customer value perception, competition, and profitability goals (gidiagba 2023). benefits of target costing: according to gidiagba (2023), the benefits of target costing include but not limited to the following: enhanced cost management: target costing provides a systematic framework for managing costs throughout the product lifecycle, allowing organizations to proactively identify and control costs. customer focus: by incorporating customer requirements and market dynamics into cost planning, target costing ensures that products are designed to meet customer needs and price expectations. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset competitive advantage: target costing enables organizations to achieve cost leadership by optimizing costs while maintaining product quality and value. profitability improvement: by aligning cost targets with profit objectives, target costing helps organizations improve profitability by achieving the desired profit margin. cross-functional collaboration: target costing promotes collaboration between design, engineering, procurement, and manufacturing teams, leading to better cost control and innovation. cost optimization techniques and tools simulation and optimization models simulation and optimization models are valuable tools used in cost optimization in manufacturing. these models enable manufacturers to analyze complex systems, simulate various scenarios, and identify optimal solutions for cost reduction and operational improvement (vonronne 2012). simulation models replicate real-world processes using mathematical and statistical techniques. simulation modelling and analysis is the process of creating and experimenting with a computerized mathematical model of a physical system (chung 2010). they simulate the behavior of a manufacturing system by capturing the interactions among various variables, such as resources, activities, and constraints. simulation models can be used to assess the impact of different factors on costs, identify bottlenecks, and evaluate the effectiveness of potential cost optimization strategies. key characteristics of simulation models according to van-ronne (2012) include: 1. input variables: simulation models incorporate input variables such as production volumes, resource availability, demand patterns, and process parameters. ii. system representation: the model represents the manufacturing system's structure and processes, including production lines, workstations, material flows, and scheduling rules. iii. replication and iteration: simulation models are often run multiple times to generate statistical output and assess system performance under different scenarios. iv. analysis and optimization: simulation models enable the analysis of cost-related metrics, such as production costs, cycle times, inventory levels, and resource utilization. they can also be used to optimize system performance by identifying improvement opportunities and testing different cost-saving strategies. simulation models are categorized based on three dimensions, namely randomness, data organization and timing of change (mourtzis et al., 2014). simulation consists of an indispensable set of technological tools and methods for the successful implementation of digital manufacturing since it gives room for the experimentation and validation of process, configuration as well as system design. simulation methods and tools are factory layout design, material and information flow design, manufacturing networks design, manufacturing systems planning and control, manufacturing networks planning and control, augmented and virtual reality in product and process design, planning and verification, ergonomics, robotics etc (mourtzis et al., 2014). out –bound manufacturing operations has a big challenge of identifying the benefits of collaboration. confusion around the optimum number of partners, investment in collaboration and duration of partnership are some of the barriers of healthy collaborative arrangements that should be surpassed (ramanathan 2014). out-bound manufacturing operations is the valuemailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset adding of activities from the initial raw materials to the ultimate consumption of the finished product spanning across multiple suppliercustomer links (dugal et al., 2011). optimization models form a significant area of research in various disciplines, including mathematics, operations research, engineering, and computer science. these models aim to find the best possible solution for a given problem by optimizing certain objective functions and subject to specific constraints (fazli-khalaf et al., 2019). one widely studied category of optimization models is linear programming (lp), which involves linear relationships between variables and constraints. the simplex algorithm, proposed by george dantzig in 1947, is a fundamental method used to solve lp problems. nonlinear programming (nlp) extends optimization to handle non-linear objective functions and constraints. nlp models are commonly solved using techniques such as gradient-based methods, interior-point methods, or evolutionary algorithms. integer programming (ip) deals with optimization problems where the decision variables must take integer values (mourtzis and nicholls 2020). these models are often more challenging to solve compared to linear programming. additionally, there are specialized optimization models such as network optimization, stochastic optimization, dynamic programming, and convex optimization, each with their own specific techniques and applications. optimization models use mathematical algorithms and techniques to determine the best allocation of resources and optimize decision-making (mourtzis. and nicholls 2020). these models aim to find optimal solutions that minimize costs, maximize efficiency, or achieve other desired objectives. optimization models can be used to address various cost optimization problems in manufacturing, including production planning, scheduling, capacity allocation, inventory management, and supply chain optimization. key characteristics of optimization models according to mourtzis and nicholls (2020) include: objective function: optimization models define an objective function that quantifies the goal to be achieved, such as minimizing costs or maximizing profit. decision variables: these variables represent the decision options available, such as production quantities, resource allocations, or inventory levels. constraints: optimization models incorporate constraints that reflect the limitations and requirements of the manufacturing system, such as capacity constraints, demand constraints, or resource availability constraints. solving techniques: optimization models employ mathematical programming techniques such as linear programming, mixed-integer programming and dynamic programming to find optimal solutions. sensitivity analysis: optimization models can be used to perform sensitivity analysis, which helps understand the impact of changes in input parameters on the optimal solution and cost outcomes. simulation and optimization models offer several benefits for cost optimization in manufacturing. these models help identify cost-saving opportunities, optimize resource allocation, and streamline processes, leading to overall cost reduction. simulation and optimization models provide decision-makers with valuable insights and data-driven recommendations for making informed cost optimization decisions. simulation models allow manufacturers to assess the impact of uncertainties, such as demand fluctuations or supply disruptions, on costs and performance. simulation models assist in identifying process bottlenecks, inefficiencies, and improvement areas (mourtzis and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset nicholls 2020). optimization models optimize resource allocation, production planning, and scheduling to minimize costs and maximize operational efficiency. simulation and optimization models can be integrated with other cost optimization techniques, such as activity-based costing, lean manufacturing, or six sigma, to provide a comprehensive approach to cost optimization. for example, simulation models can evaluate the impact of lean initiatives or six sigma projects on costs and process performance (chang 2010). simulation and optimization models are powerful tools in cost optimization. they enable manufacturers to analyze complex systems, simulate scenarios, and identify optimal solutions for cost reduction, process improvement, and resource optimization. by leveraging these models, organizations can make data-driven decisions to enhance their cost competitiveness and operational efficiency (mourtzis and nicholls 2020). conclusion manufacturers aiming to stay competitive have therefore an essential aim in lowering production costs. great promise for cost reduction and efficiency improvement exists by mixing classic methods—such as lean manufacturing and six sigma—with modern technologies such as io, machine learning, and big data analytics. still, accomplishing this effectively calls for a tailored approach addressing issues particular to every sector. future research should focus on improving these technologies and exploring their potential for collaborative use to maximize modern manufacturing systems for cost savings. achieving continuous operational excellence in manufacturing will ultimately depend on a customized approach to cost control. references ahlaqqach, m., benhra, j., mouatassim, s.and lamrani, s. (2020). closed loop location routing supply chain network design in the end of life pharmaceutical products. supply chain. forum 21, 79–92. andradottir s. (2006) recent nueral network simulation based optimization techniques: review of application.siam journal on optimization, 13(3), 666-701. bai, q., xu, x., xu, j., and wang, d. (2016). coordinating a supply chain for deteriorating items with multifactor-dependent demand over a finite planning horizon. appl. math. model. 40, 9342–9361. [cross-ref] birge j. and louveaux f. (2011)) a robust dynamic programming approximation for a stochastic inventory routing problem. transportation science, 34, 52-79. chakraborty, d., jana, d.k. and roy, t.k. (2018). two-warehouse partial backlogging inventory model with ramp type demand rate, three-parameter weibull distribution deterioration under inflation and permissible delay in payments. comput. ind. eng. 123, 157–179. [crossref] chang, w. l., huang, c. m. and chen, j. h. (2020). cost optimization of production planning for a cold chain system with carbon emission considerations. international journal of production economics, 230, 107792. doi: 10.1016/j.ijpe.2020.107792 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset chung, c. (2010). simulation modelling handbook. a practical approach, 1st edition. crc press boca rcton. 20100. conn a., scheinberg k. and vicente l. (2009) sample path optimization in simulation. in: j. tew. s. manivannan, d. sadowski, and seila (eds). proceedings of 2008 winter simulation conference, pp.237-248. cooper, g. and slagmulder, e. (2008). interorganizational cost management and relational context. accounting, organizations and society, 28(1), 1-25. deng g. and ferris m., (2007). multi-objective linear programming model for a citrus supply chain network design: metaheuristic algorithms. j. optim. ind. eng. 14, 137–154. dolan m. and more j.,( 2012) application of mixed integer linear programming in manufacturing cost reduction. . international journal of advanced science and technology. 28. 1-5. dugal, i., healy, m. and tankentoo, s. (2011). supply chain management: a challenge to change; coopers and lyband report. fazli-khalaf, n., khalilpourazari, s. and mohammadi, m. (2019). mixed robust possibilistic flexible chance constraint optimization model for emergency blood supply chain network design. ann. oper. res. 283, 1079–1109. . fu m., glover, f and april, j. (2011) simulation optimization: a review, new developments and applications. in: m.e kuhi,n.m. steiger.,f.b armstrong, and j. a jones (eds), proceedings of the 2011 winter simulation conference,pp.73-85. gidiagba n. (2023) application of target costing in manufacturing cost minimization in developing economy. international journal of engineering and innovative technology.(ijeit). (4) 4, 2022-232. gunasekaran, a., and ngai, e. w. (2004). the successful management of a small logistics company through an activity-based costing approach. international journal of production economics, 87(3), 321-331. gunasekaran, a., patel, c. and tirtiroglu, e. (2001). performance measures and metrics in a supply chain environment. int. j. oper. prod. manag. 21, 71–87. halim, m.a., paul, a., mahmoud, m., alshahrani, b., alazzawi, a.y. and ismail, g.m. (2021). an overtime production inventory model for deteriorating items with nonlinear price and stock dependent demand. alex. eng. j. 60, 2779–2786. [cross-ref] mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset hong l. and nelson b. (2009) a simulation-based procurement assessment framework in global wheat supply chain networks. j. oper. res. soc. 74, 1242–1261. huang, y.s., fang, c.c. and lin, y.a. (2019) computers & industrial engineering inventory management in supply chains with consideration of logistics, green investment and different carbon emissions policies. comput. ind. eng. 139, 106207. [cross ref] ittner, c. d., and larcker, d. f. (2011). assessing empirical research in managerial accounting: a value-based management perspective. journal of accounting and economics, 32(1-3), 349-410. jain, s., sekonyela, r., knox, b., palmer, j., huttenlocher, a., kabbage, m.and keller, n. (2018) a forward genetic screen in zebrafish identifies the g-protein-coupled receptor casr as a modulator of sensorimotor decision making current biology: cb 28(9):1357-1369.e5 journal. id: zdb-pub180424-2. jing, f. and mu, y. (2019). forecast horizon for dynamic lot sizing model under product substitution and perishable inventories. comput. oper. res. 110, 77–87. [cross-ref] khakzad, a. and gholamian, m.r. (2020). the effect of inspection on deterioration rate: an inventory model for deteriorating items with advanced payment. j. clean. prod. 254, 120117. lee, g, jui, y and veuio, m. (2015) integrated optimization models for the dynamic facility location and allocation problem. int. j. prod. res. 46, 2070–2094. maihami, r., govindan, k. and fattahi, m. (2019). the inventory and pricing decisions in a three-echelon supply chain of deteriorating items under probabilistic environment. transp. res. part e logist. transp. rev. 131, 118–138. [cross-ref] minner, s. and transchel, s. (2017). order variability in perishable product supply chains. eur. j. oper. res. 260, 93–107. [cross-ref] mishra, u., wu, j.z. and sarkar, (2020), b. optimum sustainable inventory management with backorder and deterioration under controllable carbon emissions. j. clean. prod. 279, 123699. [cross-ref] mohammadi, b., taleizadeh, a.a., noorossana, r. and samimi, h. (2015). optimizing integrated manufacturing and products inspection policy for deteriorating manufacturing system with imperfect inspection. j. manuf. syst. 37, 299–315. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mourtzis, d., dowkas,m. and bernidaki, d.(2014). simulation in manufacturing: review and challenges. the elsevier b. v international scientific committee of the 8th international conference on digital enterprise technologydet. dio:10.1016/j.procir.10.032 2212-8271. mourtzis d. and nicholls g.,( 2020).optimal production-distribution planning in supply chain management using linear programming approach. in simulation conference procedings. muriana, c. (2016). an eoq model for perishable products with fixed shelf life under stochastic demand conditions. eur. j. oper. res. 255, 388–396. [crossref] pal, s., mahapatra, g. and samanta, g. (2015). a production inventory model for deteriorating item with ramp type demand allowing inflation and shortages under fuzziness. econ. model. 46, 334–345. panda, s. and modak, n. (2017). coordination and benefit sharing in a three-echelon distribution channel with deteriorating product. comput. ind. eng. 113, 630–645. peters j., vijayakumar s. and schaal s., (2013) a locally derivative-free optimization (dfo) model for supplier selection in pharmaceutical industry. applied mathematical modelling, 38, 3714-3726. ramanathan, u. (2014). performance of supply chain collaboration: a simulation study, expert systems with applications. (41) 1 210-220. satyajith, a., nikolaos, v., bikram, s and scott, j. (2016,). a generic simulation-based logistics assessment framework in global pharmaceutical supply chain networks. j. oper. res. soc. 74, 1342–1360. von ronne, j.(2012). simulation: overview and taxonomy, presentation/ technical report ieee. wang h. and pasupathy r. (2012) a stochastic linear programming approach for supply chain network design under uncertainty. eur. j. oper. res. 157, 93–112. womeck, e. and jones,n. (2003) a cost optimization technique of closed-loop supply chain considering customer satisfaction. international journal of production economics, 226, 106685. doi: 10.1016/j.ijpe.2020.107795. xu, x. bai, q. and chen, m. (2017). a comparison of different dispatching policies in two-warehouse inventory systems for deteriorating items over a finite time horizon. appl. math. model. 41, 359–374. [cross-ref] yu, c., qu, z., archibald, t.w. and luan, z. (2020). an inventory model of a deteriorating product considering carbon emissions. comput. ind. eng. 148, 106694. [cross-ref] mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset yu, j.c. (2019). optimizing a two-warehouse system under shortage backordering, trade credit, and decreasing rental conditions. int. j. prod. econ. 209, 147–155. [cross-ref] zeng, s., bai, x., and wang, y. (2020). a cost optimization model of closed-loop supply chain considering customer satisfaction. international journal of production economics, 228, 107785. doi: 10.1016/j.ijpe.2020.107785 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 42 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assessment of the quality of hand dug well used for drinking and agricultural activities at blama, small-bo chiefdom, eastern, sierra leone mohamed junior pujeh*, yahaya kudush kawa, jonathan kpaka and umaru kanneh department of chemistry, school of environmental sciences njala university, sierra leone. doi: https://doi.org/10.5281/zenodo.10592703 abstract: this research investigates the microbial and physicochemical characteristics of five local hand dug wells used for drinking and agricultural activities in blama, small-bo chiefdom, in the kenema district, eastern province of sierra leone. these five local hand-dug wells were randomly selected based on the availability of water in them throughout the year. the physical characteristics examined are: ph, turbidity, conductivity, temperature, total dissolve solid (tds); and the chemical characteristics, such as: residual chlorine (r. chorine), magnesium, potassium, nitrite, iron, fluoride, ammonia, copper; and the microbial characteristics include: total coliforms, fecal coliform and non-fecal coliform. samples were collected in 500 ml sterilized plastic containers and transported to the laboratory, within 30 min. the results analysed indicate that the physical and chemical characteristic are within the who guideline limits for safe drinking water. however, a large amount of nonfaecal coliform was recorded in all the water samples analysed which exceed the world health organization standard for non-faecal coliform ((<10), and with no presence of residual chlorine. it can therefore be concluded that the water sample analyzed was potable and fit for drinking and agricultural activities. keywords: hand-dug, well, local, safe and sample. introduction globally, 2.2 billion people lack access to safely managed drinking water at home (who/unicef, 2019). safe drinking water is defined as "water with microbial, chemical and physical characteristics that meets who guidelines or national standards on drinking water quality (who/unicef, 2019). according to who, for water to be qualified as being ―safely managed‖, drinking water must meet three criteria: be accessible on the premises, be available for at least 12 h/day, and be free from escherichia coli, arsenic, or fluoride contamination. who/unicef (2017) report stated that an estimated 5.3 billion people had access to safely-managed drinking water, of that number, 1.4 billion used basic services, 206 million used limited services, 435 million used unimproved sources, and the remaining 144 million relied on untreate surface water according to world water development report (2019) on the disparities between the rich and the poor, on a global scale, half of the people who drink water from unsafe sources live in africa. in sub-saharan africa, only 24% of the populations have access to safe drinking water, and 28% have basic sanitation facilities that are not shared with other households (unicef/who, 2017). access to clean and safe water continue to be a major challenge for citizens of sierra leone. the water aid (2017) report stated that more than six out of 10 people in sierra leone do not have safe water and eight out of 10 people do not have access to a decent toilet. as a result, over 1,200 children under five die mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 43 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset each year from waterborne disease in sierra leone. a recent publication by world bank (2020) stated that access to safe water in sierra leone was reported at 1 in 2020, according to collection of development indicators. access to an improved water source is currently defined as the percentage of the population that can obtain at least 20 l/person/day from an ―improved‖ source that is within 1 km of the user’s dwelling. access to clean and safe water remains an eyesore for rural and urban settlements across sierra leone. a lot of people inhabiting in rural communities of sierra leone heavily depend on hand-dug well. the preference of groundwater as a source of drinking water in rural areas is because of its relatively better quality than river water (obiri-danso et al., 2009). the country is blessed with six months of wet season and six months of dry season, during wet season (may to october) most people get their drinking and domestic water from the rains which reduced the burden on people in search of water for drinking and domestic purposes. in the dry season (november to april), the availability of potable water sometimes poses a major challenge for most families. the urban settlements such as bo, kenema, and makeni seldomly received potable water from the sierra leone water company (salwaco) and guma valley water company for the capital freetown. water is an essential part of human nutrition and is required for maintenance of personal hygiene, food production and prevention of diseases (thliza et al., 2015). it is absolutely necessary for most life driven processes (aroh et al., 2013). quality water is colorless, tasteless, odourless, as well as free from faecal contamination (opara and nnodim, 2014). blama is the chiefdom headquarter of small-bo, with an estimated population of 8,146, according to statistics sierra leone (ssl, 2021 population census of cities/towns). before the start of the civil war in march, 1991, there were pipe borne water facilities at principal roads of blama. but as a result of the 10-year civil war, most of the government infrastructures and water channels were destroyed, leaving the wreckages as existential evidence of today’s monument. the availability of clean and safe drinking water has become a major issue at blama. at present, the major sources of available drinking water at blama are hand-dug well, river water, swamp water, hand pump wells and streams. the dug well is a traditional method of withdrawing groundwater from the upper layer of a water table by constructing a well of large diameter, typically lined by concrete rings and enclosed by a concrete slab or metal sheet with ventilation (howard et al., 2006; bain et al., 2014). in rural areas of developing countries, the great majority of health-related water quality problems are the result of bacteriological or other biological contamination (who, 1997). a similar report published by statistics sierra leone (stats ssl, 2017), with the technical support of unicef, conducted a multiple indicator cluster survey (mics) to collect internationally comparable data on a wide range of indicators. the survey revealed that almost 90% of the drinking water at household level contained the e. coli bacteria, presenting a serious health threat to citizens. the poor and marginalized people living in rural and peri-urban settlements are most in need for improved and safe drinking water, appropriate forms of sanitation and access to water for other domestic purposes (crow, 2001). studies carried out in different areas of the world indicate that most of the sources of domestic water have an alarming level of microbiological pollution (mpakam, 2009; oladipo et al., 2009; prasanna and reddy, 2009; kuitcha et al., 2010; khaniki et al., 2010; oyedeji et al., 2010). in 2012, there was a cholera outbreak in sierra leone, according to who report (2012), there was 18,919 cases reported with 273 deaths. cholera is a water borne disease that is caused by drinking contaminated water. report from epidemiology (cdc, 2012) research mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 44 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset has shown that cholera is predominant in sub-saharan africa where clean water and sanitation remains a major problem. the objective of this study was to examine, the bacteriological and physicochemical characteristics of five local hand dug wells consumed at blama, small-bo chiefdom, in the kenema district, eastern province of sierra leone, and hence find a suitable remedy to help improve the quality of these residential wells and also ensured that water quality test is conducted on all residential wells before it is being consumed. materials and methods description of study area blama is the chiefdom headquarter town of small-bo, in the kenema district, eastern sierra leone. it lies approximately 12 miles away from kenema. it is found on latitude 7° 52' 29" n and longitude 11° 20' 43" w. blama is a fairly big town with an estimated population of 8,146 (ssl, 2021 population census of cities). the major activity of the people of this community is farming and animal husbandry. five hand dug wells drawn from five different locations, were selected for this study. the five hand dug wells were selected for this research base on the availability of water in the well throughout the year. google map locator was used to map out the sample collection site. the description of the sample collection area is illustrated in figure 1. figure 1. a map showing the area of study. description of sampling area five local hand dug wells located at blama, small-bo chiefdom, in the kenema district were selected for this research at random. the names of the five wells are as follows: 5 koribondo road well, 4 jimmy section well, 6 jabbie street well, 3 jabbie street well, and 19 koribondo road well. these five hand dug wells were used by the locals of that community for drinking and agricultural activities. the study started in december, 2020, and run through may, 2021, a six months intensive water quality examination. these five hand dug wells were selected for this research based on the availability of water in them throughout the year without drying up. sampling a sterilized cup with a string tied to the cup was used to collect water from the well. the sterilized container was rinsed three times with the water sample to be tested for. the water sample was centrally poured into the sterilized container (500 ml), to avoid water touching the inside mouth surface of the container, in order to avoid contamination. the water sample was then transported to the laboratory (directorate of water resources, in the ministry of water resources, bo city) for physicochemical and bacteriological assessment. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 45 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset sample collection and analysis physical parameters the analysis for the physical parameters was conducted according to instructional manual (wagtech international, we30210). total dissolve solid and electrical conductivity in the examination of electrical conductivity (µs/cm) and total dissolved solids (mg/l) of the water sample, a digital conductivity with electrode was employed to determine the concentration of tds and ec after the electrode was switched on and duplicate values recorded. a clean tissue paper was used to wipe the electrode dry before being reused. ph a digital ph meter with electrode was used to measure the ph. it was done by inserting the electrode into the water sample and the electrode turned on, the values were taken in duplicates. turbidity a photometer, 7100 was used. in the determination of the level of turbidity, a blank solution was prepared to calibrate the photometer. a test tube containing 10 ml of water was placed in the basin and covered with light black cap and power turned on. duplicate values were recorded. it is measured in nephelometric turbidity unit (ntu). temperature the examination for temperature was done by placing the digital thermometer into the water sample and electrode switched on; duplicated values were recorded in °c. chemical characteristics determination wagtech photometer, 7100, was used to investigate the chemical characteristics. before the analysis, references were drawn from the operational manual. a blank solution (reference, 0.00 mg/l) was first prepared to calibrate the photometer. a test tube containing 10 ml water sample was placed one tablet (chemical), it was then crushed and stirred to allow a homogenous mixture and allowed to stand for 10 min for full colouration. it was then inserted in the cell holder and lid closed. the photometer was adjusted to the appropriate wavelength and power turned on, the concentrate of each sample was recorded in mg/l. microbial determination total coliform count, e. coli, and faecal coliform 500 ml of each of the five samples collected from the wells was transported to the water quality directorate for the examination of e. coli, faecal coliform and non-faecal coliform. who permissible standard for the presence of faecal coliform in water is 0 count/100 ml. the membrane filtration method was used to assess the bacteriological parameters, after the culture media had been produced. the water samples were allowed to pass through a membrane pore space of 0.45 µm, bacteria were trapped on the membrane surface. the membrane was placed in a petri dish containing ―m-faecal coliform broth (park scientific limited)‖ and was incubated at 44°c for 18 to 24 h. examination was done based on colour indicator, blue-green for e. coli and pink for nonfaecal coliform colonies. results and discussion mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 46 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the results of the physicochemical and bacteriological parameters of the five hand dug wells used for drinking and agricultural activities were presented in statistical methods (mean, variance, and standard deviation). the results of the various samples are illustrated in tables 1 to 5. physicochemical parameters from the results, the mean temperature of all the water samples was examined. 5 koribondo rd (28.62°c), 4jimmy section (28.12°c), 6jabbie street (28.50°c), 3 jabbie street (28.32°c) and 19 koribondo road (28.52°c) fell outside the world health organization (who) permissible limits. who does not have any temperature standard for safe water, but recommended that safe water must have a temperature of 25°c at a ph of 7. environmental factors such as soil nature, the depth of water level and other anthropogenic matters can influence the temperature of drinking water. weather patterns have also been known to increase or decrease the temperature of water. in water quality examination, temperature plays a pivotal role in influencing both the absorption of chemical and the multiplication of microbial organism. the mean ph obtained for all the water samples (tables 1 to 5) was analysed: 5 koribondo road (6.67), 4 jimmy section (6.64), 6 jabbie street (6.30), 3 jabbie street (6.55), and 19 koribondo road (6.73), fell within the who permissible limits, except the 6 jabbie street water sample, that recorded a low ph mean value. who recommended that drinking water should have ph of 6.5 to 8.5. an increased carbon dioxide concentration may therefore lower ph, whereas a decrease may cause it to rise (who, 2003). the ph of most raw water lies within the range of 6.5 to 8.5 (who, 2003). from tables 1 to 5, the mean electrical conductivity and the total dissolved solids for all the water samples were analysed: 5 koribondo road (129.38 µs/cm, 63.63 ppm), 4 jimmy section (145.07 µs/cm, 72.72 ppm), 6 jabbie street (158.52 µs/cm, 79.30 ppm), 3 jabbie street (114.85 µs/cm, 57.08 ppm), and 19 koribondo road (95.03 µs/cm; 47.08 ppm) fell within the who permissible limits. who recommended standard for electrical conductivity and the total dissolved solids in drinking water is <450 µs/cm and <248 ppm, respectively. from tables 1 to 5, the mean turbidity value for all the water samples examined was: 5 koribondo road (0.04 ntu), 4 jimmy section (0.04 ntu), 6 jabbie street (0.69 ntu), 3 jabbie street (1.04 ntu), and 19 koribondo road (0.38 ntu) fell within the who acceptable limits. who standard for turbidity of acceptable water drinking was <5.0 ntu. from tables 1 to 5, the chemical characteristics for all the water samples examined fell within the who permissible limits for safe water. the chemical characteristics for the various wells were as follows: 5 koribondo road (r. chlorine 0.00 mg/l, magnesium 6.33 mg/l, potassium 1.73 mg/l nitrite 0.11 mg/l, fluoride 0.01 mg/l, iron 0.02 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 4 jimmy section (r. chlorine 0.00 mg/l, magnesium 11.33 mg/l, potassium 2.52 mg/l, nitrite 0.06 mg/l, fluoride 0.01 mg/l, iron 0.01 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 6 jabbie street (r. chlorine 0.00 mg/l, magnesium 11.67 mg/l, potassium 2.30 mg/l, nitrite 0.32 mg/l, fluoride 0.06 mg/l, iron 0.00 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 3 jabbie street (r. chlorine 0.00 mg/l, magnesium 2.27 mg/l, potassium 1.07 mg/l, nitrite 0.28 mg/l, fluoride 0.00 mg/l, iron 0.00 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l); 19 koribondo road (r. chlorine 0.00 mg/l, magnesium 12.33 mg/l, potassium 2.07 mg/l, nitrite 0.52 mg/l, fluoride 0.01 mg/l, iron 0.01 mg/l, ammonia 0.00 mg/l, copper 0.00 mg/l). all the chemical parameters analysed are within the who limits. microbial parameters e. coli and faecal coliform mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 47 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset tables 1 to 5 show no presence of e. coli and faecal coliform in all the water samples examined, 5 koribondo road (0.00 cfu/100 ml, 0.00 cfu/100 ml), 4 jimmy section (0.00 cfu/100 ml, 0.00 cfu/100 ml), 6 jabbie street (0.00 cfu/100 ml, 0.00 cfu/100 ml), 3 jabbie street (0.00 cfu/100 ml, 0.00 cfu/100 ml), 19 koribondo road (0.00 cfu/100 ml, 0.00 cfu/100 ml). non-faecal coliform the results from tables 1 to 5 show a high mean value of table 1. hand dug well at 5 koribondo road, blama. month standard parameter mean variance who dec. jan. feb. march april may deviation temperature (°c) 28.20 26.90 30.00 29.60 28.60 28.40 28.62 1.21 1.09 no value ph 6.19 7.74 6.80 6.52 6.72 6.02 6.67 0.37 0.61 6.5-8.5 conductivity (µs/cm) 94.00 163.9 173.00 76.30 94.00 175.10 129.38 49.54 7.04 tds (ppm) 47.00 81.80 86.40 38.10 47.00 81.50 63.63 474.57 21.78 248 turbidity (ntu) 0.00 0.00 0.00 0.24 0.00 0.00 0.04 0.08 0.28 r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.3-0.5 magnesium (mg/l) 6.00 6.00 8.00 0.00 8.00 10.00 6.33 11.87 3.44 potassium (mg/l) 2.00 2.12 2.14 2.14 0.00 2.00 1.73 0.73 0.85 nitrite (mg/l) 0.12 0.12 0.14 0.02 0.14 0.12 0.11 0.00 0.02 fluoride (mg/l) 0.02 0.00 0.00 0.01 0.01 0.01 0.01 0.00 0.02 iron (mg/l) 0.03 0.02 0.01 0.02 0.02 0.01 0.02 0.00 0.01 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 no value copper (mg/l) 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 12.00 12.00 16.00 14.00 14.00 12.00 13.33 2.67 1.63 <10 cfu/100 ml table 2. hand dug well at 4 jimmy section, blama. month standard parameter mean variance who dec. jan. feb. march april may deviation temperature (°c) 28.10 26.20 30.00 28.80 28.10 27.50 28.12 1.61 1.27 no value ph 5.68 7.74 6.74 6.86 6.68 6.14 6.64 0.49 0.69 6.50-8.5 conductivity (µs/cm) 172.10 135.4 111.80 145.90 172.00 133.20 145.07 466.31 21.59 450 tds (ppm) 86.60 67.60 55.90 73.10 86.60 66.50 72.72 146.65 12.11 248 turbidity (ntu) 0.00 0.00 0.00 0.23 0.00 0.00 0.04 0.01 0.09 5.0 r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.30-0.50 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 48 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset magnesium (mg/l) 12.00 10.00 10.00 12.00 10.00 14.00 11.33 2.67 1.63 potassium (mg/l) 2.64 2.66 2.60 2.60 2.40 2.20 2.52 0.03 0.18 nitrite (mg/l) 0.06 0.06 0.10 0.06 0.04 0.02 0.06 0.00 0.03 fluoride (mg/l) 0.01 0.01 0.00 0.01 0.00 0.00 0.01 0.00 0.01 iron (mg/l) 0.01 0.01 0.00 0.00 0.01 0.00 0.01 0.00 0.00 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 no value copper (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100ml non-faecal coli 16.00 14.00 14.00 16.00 16.00 14.00 15.00 2.40 1.55 <10cfu/100ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 14.00 12.00 14.00 14.00 12.00 12.00 13.00 1.20 1.09 <10 cfu/100 ml turbidity (ntu) 2.00 2.00 2.00 0.26 0.00 0.00 1.04 1.11 1.05 <𝟓 . table 4. hand dug well at 3 jabbie street, blama. parameter month mean variance standard deviation who dec. jan. feb. march april may temperature (°c) 28.30 26.10 30.00 29.40 28.60 27.50 28.32 2.00 1.42 no value ph 5.63 7.59 5.97 6.76 6.63 6.70 6.55 0.47 0.68 6.5 8.5 conductivity ( µs/cm) 151.00 107.10 106.60 56.20 151.00 117. 20 114.85 1237.42 35.18 tds (ppm) 75.50 53.90 53.10 28.10 75.50 56.40 57.08 308.97 17.58 < 𝟐 𝟒 𝟖 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 49 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset r. chlorine (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.3-0.5 magnesium (mg/l) 16.00 14.00 12.00 14.00 14.00 12.00 13.67 2.27 1.51 < 𝟎𝟎.𝟎 potassium (mg/l) 2.46 2.70 0.00 2.74 2.24 2.20 2.06 1.07 1.03 nitrite (mg/l) 0.06 0.16 0.14 1.14 1.16 0.16 0.47 0.28 0.53 fluoride (mg/l) 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.00 iron (mg/l) 0.04 0.02 0.01 0.01 0.02 0.01 0.02 0.00 0.01 ammonia (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 copper (mg/l) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 e. coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml faecal coli 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 cfu/100 ml non-faecal coli 12.00 12.00 12.00 14.00 12.00 12.00 12.33 0.67 0.82 <10 cfu/100 ml to exist and grow in soil and water environments and is therefore considered a poor parameter for measuring the presence of pathogens (stevens et al., 2003). total coliform bacteria are not acceptable indicators of the sanitary quality of rural water supplies, particularly in tropical areas where many bacteria of no sanitary significance occur in almost all untreated supplies, (who, 1997). an exception is e. coli, a thermotolerant coliform, the most numerous of the total coliform group found in animal or human faeces, rarely grows in the environment and is considered the most specific indicator of fecal contamination in drinking-water (who, 2004). the presence of e. coli provides strong evidence of recent fecal contamination (who, 2004, stevens et al., 2003). from figure 2, the highest conductivity and told dissolved solid was recorded by table 3 (hand dug well at 6 jabbie street, blama) followed by table 2 (hand dug well at 4 jimmy section, blama). the highest ph was recorded by table 5 (hand dug well at 19 koribondo road, blama) and the lowest by table 3 (hand dug well at 6 jabbie street, blama). all the chemical parameters measured fall within the who permissible standards. figure 3. the mean physicochemical parameters of the five hands dug well. no value mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 50 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset from figure 3, the highest non faecal coli was recorded by table 2 (hand dug well at 4 jimmy section, blama), followed by table 1 (hand dug well at 5 koribondo road, blama), the lowest was recorded by table 5 (hand dug well at 19 koribondo road, blama). all the non faecal coliform recorded for the five wells fell above the who permissible bracket (non-faecal coliformis <10 cfu in 100 ml. the high level of non-faecal coliform in all the five samples could be as a result of contaminated water or animal waste that moves quickly down the groundwater, resulting in the variation of non-faecal coliform level. conclusion the objective of this research is to determine the potability of five hand dug wells used for drinking and agriculture activities in blama, small-bo chiefdom, kenema district, eastern, sierra leone. in as much as safe drinking water plays a fundamental role in the life of all living organisms, it is therefore incumbent on us all to maintain its hygienic component properly. from the results of the analysis, it can be said that the physicochemical and microbial parameters of all the water samples examined are within the who permissible limits, except for the non-faecal coliform presences in all the water samples analysed which exceed the who limits and the lack of residual chlorine in all the water samples. it can therefore be concluded that all the water samples examined are safe and fit for drinking. conflict of interests the authors have not declared any conflict of interests. references aroh kn, eze em, ukaji d, wachuku ck, gobo ae, abbe sd, teme sc, igoni ah (2013). health and environmental components of sachet water consumption and trade in aba and port harcourt, nigeria. journal of chemical engineering and material science 4(2):13-22. bain r., cronk r, wright j, yang h, slaymaker t, bartram j (2014). fecal contamination of drinking-water in low-and middle-income countries: a systematic review and meta-analysis. plos medicine 11(5):e1001644. crow b (2001). water: gender and material inequalities in the global south. howard ahmed g, shamsuddin mf, mahmud af, deere sgd (2006). risk assessment of arsenic mitigation options in bangladesh. journal of health, population and nutrition 24(3):346-355 jeremiah kt, jonathan aqb (2018). bacteriological contamination of groundwater in relation to septic tanks location in ashanti region, ghana. kuitcha d, ndjama j, tita am, lienou g, kamgang k, beyala v, ateba bh, ekodeck ge (2010). bacterial contamination of water points of the upper mfoundi watershed, yaounde, cameroon. african journal of microbiology research 4(7):568-574. khaniki grj, zarei a, kamkar a, fazlzadehdavil m, ghaderpoori m, zareim a (2010). bacteriological evaluation of bottled water from domestic brands in tehran markets in iran. world applied science journal 8(3):274-278. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 51 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mpakam hg (2009). vulnérabilité à la pollution des ressources en eaux à bafoussam et incidences socioéconomiques et sanitaires: modalités d’assainissement.th. doct. phd, univ. yaoundé i. p 267. opara au, nnodim j (2014). prevalence of bacteria in bottled and sachet water sold in owerri metropolis. international journal of science innovations and discoveries 4(2):117-122. oladipo ic, onyenike ic, adebiyi ao (2009). microbiological analysis of some vended sachet water in ogbomoso, nigeria african journal of food science 3(12):406-412. obiri-danso k, adjei b, stanley kn, jones k (2009). microbiological quality and metals in wells and boreholes water in some peri-urban communities in kumasi, ghana. african journal of environmental science and technology 3(3):059-066. oyedeji o, olutiola po, moninuola ma (2010). microbiological quality of packaged drinking water brands marketed in ibadan metropolis and ileife city in south western nigeria. african journal of microbiology research 4(1):096-102. prasanna rb, reddy ms (2009). bacteriological examination of drinking water with reference to coliforms in jeedimetla, hyderabad, india. african journal of biotechnology 8(20):5506-5507. stevens m, ashbolt n, cunliffe d (2003). recommendation to change the use of coliform as microbial indicators of drinking water quality. australia government national health and medical research council. thliza la., khan au, dangora db, yahaya a (2015). study of some bacterial load of some brands of sachet water sold in ahmadu bello university (main campus), zaria, nigeria. international journal of current science 14:91-97. sierra leone (stats ssl) (2017). multiple indicator cluster survey. https://www.unicef.org/sierraleone/media/391/file/slmics-report 2017.pdf.pdf sierra leonean (2012). cholera outbreak wikipedia. https://en.wikipedia.org/wiki/2012_sierra_leonean_cholera_outbreak cdc (2012). treatment and prevention in sierra leone zainab blell mph student. https://slideplayer.com/slide/12371900/ world bank (2020). report on access to water in sierra leone. who/unicef ( 2019). joint monitoring programme (jmp) for water supply, sanitation and hygiene. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 52 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset who/unicef (2017). joint monitoring programme. progress on household drinking, sanitation and hygiene (2000-2017). world health organization (who) (2004). guidelines for drinking water quality, 3rd ed. volume 1. recommendations. world health organization – geneva. world health organization (who) (2003). guidelines for drinking-water quality, 2nd ed. vol. 2. health criteria and other supporting information. world health organization, geneva, 1996.world health organization (1997). guidelines for drinking-water quality —2nd ed. geneva. mailto:topacademicjournals@gmail.com chapter one academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset cryonics suspension and digital communication: reimagining continuity and consciousness in humanity's future eke, chigozi (phd) department of linguistics and communication studies, university of port harcourt, rivers state, nigeria. e-mail: chigozi_eke@uniport.edu.ng phone no.: 08033733954 doi: https://doi.org/10.5281/zenodo.17176054 abstract: this research examined cryonics suspension and digital communication: reimagining continuity and consciousness in humanity's future. media technological determinism and cybernetic ontology theories formed the anchor for this research. this study adopted a phenomenological research methodology to explore how individuals conceptualize and experience the intersection of cryonics suspension and digital communication as pathways to posthumous continuity and consciousness. the target population consists of approximately 150 individuals globally, including cryonics practitioners, trans-humanist thinkers, digital legacy developers, neuroethicists and ai technologists, who are directly engaged with or have scholarly or professional insights into human identity preservation technologies. these individuals are drawn from institutions such as the alcor life extension foundation, kriorus, academic research centres and digital innovation labs in countries like the united states, russia, germany, south africa and nigeria. a purposive sample of 20 participants were selected using expert sampling and data were collected through in-depth, semi-structured interviews conducted virtually via video conferencing platforms. the data were analysed using thematic analysis, following moustakas’ phenomenological reduction steps, including horizonalization, clustering of themes, and synthesis of meanings to reveal core essences shared across participant narratives. the study found out that, while cryonics suspension techniques like vitrification can preserve the structural integrity of brain tissue, there is no current scientific evidence confirming the restoration of consciousness or cognitive function after suspension, leaving the promise of continuity through cryonics largely theoretical and technologically aspirational. the research concluded that, while cryonics shows potential for preserving the brain’s structural components, the lack of verifiable revival outcomes and unresolved scientific uncertainties about the restoration of consciousness highlight the need for further empirical research before it can be considered a reliable method of human continuity. the research recommended that, scientific research institutions such as the alcor life extension foundation, cryonics institute and global neuroscience laboratories invest in advanced, long-term studies on brain connectome preservation and revival to validate the functional outcomes of cryonics suspension. keywords: cryonics suspension, digital communication, reimagining continuity, consciousness, humanity's future mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset introduction cryonics suspension, the low-temperature preservation of human bodies after legal death in anticipation of future revival, has long hovered at the intersection of science fiction, speculative biomedical technologies and philosophical inquiry. with the increasing pace of digital innovation and the rise of posthumanist discourses, the idea of preserving not only the biological self but also the digital consciousness for potential future reanimation is gaining serious academic and technological traction. cryonics, initially considered a fringe scientific endeavour, is now being reimagined through the lens of digital communication technologies that challenge traditional notions of mortality, identity and memory (more & vita-more, 2013). as humanity ventures deeper into the 21st century, the fusion of cryonics and digital media frameworks offers a compelling paradigm for the exploration of extended consciousness and continuity, reshaping the trajectory of life and death. globally, the discourse surrounding cryonics has evolved significantly in recent decades, particularly, within technologically advanced societies such as the united states, russia and australia. pioneering organisations like the alcor life extension foundation and the cryonics institute in the united states (u.s.) have made substantial investments in advancing cryopreservation protocols, including vitrification techniques and preservation of the brain’s neural structures (alcor, 2024). russia’s kriorus has similarly expanded its international footprint, offering cryopreservation services to clients across europe and asia. meanwhile, australia has begun developing legal and ethical frameworks for cryonics, focusing on issues of consent and bodily autonomy (gorman, 2022). across these nations, there is a growing convergence between cryonics and digital communication, particularly, regarding the storage and simulation of personal memories, which is being pursued through developments in ai and brain-computer interfaces. in africa, the conversation around cryonics is still in its nascent stages, largely limited by technological, infrastructural and ethical considerations. however, pockets of scholarly and technological interest are emerging in countries like south africa and nigeria, where discussions on transhumanism, digital afterlives and neuroethics are slowly gaining ground in academic and tech communities. the increasing availability of cloud computing, block-chain technologies and ai-based data archiving is gradually opening avenues for african scholars and bioethicists to engage with the implications of digital consciousness preservation (obot, 2023). while cryonic facilities are non-existent on the continent, the discourse is being enriched through cross-border intellectual exchanges and digital platforms that facilitate knowledge transfer from the global north. at the national level, particularly, in technologically progressive countries like the united states, there has been an interdisciplinary fusion of neuroscience, informatics and philosophy in analysing the plausibility of reanimating cryopreserved individuals. this includes efforts to decode and digitally reconstruct brain connectomes, the comprehensive mapping of neural connections as a prerequisite for consciousness replication (emanuel et al., 2021). concurrently, researchers are experimenting with neural prosthetics and ai systems capable of simulating individual memory patterns, essentially creating a form of “digital twin” that can exist mailto:topacademicjournals@gmail.com tel:2013 tel:2024 tel:2022 tel:2023 tel:2021 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset independently of biological substrates (pratt et al., 2023). these developments suggest that, digital communication technologies are no longer merely auxiliary tools in cryonics but may be central to reconstituting human identity in a post-biological future. the interrelationship between cryonics suspension and digital communication is profoundly influenced by theoretical frameworks such as media determinism and cybernetic ontology, which posit that technology shapes human existence and perception of reality. digital communication serves not only as a repository for memories and experiences but also as a medium for interactive identity. social media platforms, virtual reality and augmented reality increasingly function as extensions of the self, potentially offering continuity of identity even in the absence of biological life (floridi, 2014). as these platforms become more immersive and integrated with biometric data, the boundary between biological consciousness and digital presence begins to blur, making the idea of a digitally sustained self-post-cryopreservation more tenable. from a biomedical perspective, the viability of cryonic suspension hinges on preserving the integrity of the brain's microstructure, particularly, the synaptic networks believed to house memory and consciousness. emerging research in connectomics and neuroinformatics supports the hypothesis that preserving the brain’s architecture, even in a suspended state, could allow for future revival if technological conditions permit (sandberg & bostrom, 2020). complementing this are advancements in ai-driven brain mapping and nanotechnology, which aim to bridge the gap between frozen neural tissue and active digital simulation. these technological strides suggest that, cryonics is evolving from a speculative venture into a frontier of empirical experimentation. ethical considerations surrounding cryonics and digital consciousness are also increasingly gaining scholarly attention. issues related to informed consent, identity continuity and the societal ramifications of posthumous revival are subjects of intense debate. critics argue that digital resurrection may commodify human identity, reducing complex consciousness to data patterns, while proponents advocate for the autonomy to extend life and consciousness through technological means (nuffield council on bioethics, 2023). the ethical debate is further complicated by the potential socio-economic disparities in access to these technologies, potentially creating new forms of digital and existential inequality. culturally, the notion of preserving consciousness, either biologically or digitally resonates differently across societies. while western cultures with strong individualist traditions may embrace cryonics and digital avatars as extensions of self-preservation, collectivist societies might prioritise relational continuity and spiritual beliefs that transcend technological intervention. this cultural plurality must be accounted for in global policy dialogues surrounding human preservation technologies, particularly, as digital communication technologies proliferate across varied cultural and religious landscapes (kaku, 2021). the global covid-19 pandemic further highlighted humanity’s dependence on digital platforms for maintaining continuity in social, professional and even memorial practices. virtual funerals, online memorials and digital legacy planning became mainstream, reinforcing the growing intersection between death and digital mailto:topacademicjournals@gmail.com tel:2023 tel:2014 tel:2020 tel:2023 tel:2021 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset communication. these developments arguably laid the groundwork for more radical ideas like cryonic suspension and digital consciousness transfer to be considered not only possible but necessary in a world where biological fragility is matched by technological resilience (chandler & munday, 2022). the crisis has prompted renewed interest in how digital communication can act as a scaffold for preserving human essence beyond the limits of the flesh. cryonics suspension and digital communication represent two converging pathways for reimagining continuity and consciousness in the future of humanity. while cryonics aims to preserve the physical substrates of the human mind, digital communication technologies provide the infrastructure for preserving and simulating the experiential and cognitive dimensions of the self. together, they offer a compelling vision of extended existence that challenges traditional dichotomies of life and death, body and mind, real and virtual. as global research efforts continue to advance, the philosophical, ethical and technological boundaries of this hybrid domain requires rigorous interdisciplinary scrutiny, particularly, in ensuring that the pursuit of extended consciousness remains grounded in principles of equity, autonomy and human dignity. problem statement cryonics suspension and digital communication are emerging fields that intersect at the frontier of science, technology and philosophy. while cryonics has advanced through the development of vitrification and neural preservation techniques, the integration of digital communication technologies such as artificial intelligence, memory archiving and neural simulation have introduced new possibilities for reimagining human continuity. however, the conceptual frameworks that underpin these developments remain fragmented. there is a lack of cohesive theoretical grounding that adequately explains how preserved biological substrates and digitally encoded memories might converge to constitute consciousness. this raises a theoretical conflict between materialist neuroscience, which insists on the indispensability of a living brain and posthumanist or transhumanist frameworks, which advocate for digitally simulated identities as legi timate continuations of the self. the problem is further intensified by a scarcity of empirical studies that validate the viability of such integrations, particularly, in long-term suspension scenarios where environmental and technological variables are difficult to control or predict. methodologically, existing studies tend to focus on either the technical viability of cryopreservation or the philosophical implications of digital immortality, with limited interdisciplinary research that connects both variables. there is a significant methodological gap in studies that empirically explore the interplay between digital memory preservation and cryonic procedures. furthermore, most population samples involved in current research are drawn from highly selective and ideologically homogeneous groups often western technophiles or cryonics advocates, which limits the generalizability of findings across diverse sociocultural and ethical contexts. these population gaps highlight a broader conceptual void, particularly regarding how different cultures, religions and ethical systems interpret digital and biological continuity. without cross-cultural, agemailto:topacademicjournals@gmail.com tel:2022 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset diverse and gender-inclusive data, current models risk imposing a technologically deterministic worldview that may not reflect the complexities of global human experiences and values. from a practical standpoint, the integration of cryonics and digital communication technologies is hindered by legal ambiguities, infrastructure deficits in developing regions and limited public engagement with the ethical and social ramifications of these innovations. knowledge gaps persist in terms of how such preservation methods could be scaled or democratised to avoid becoming exclusive to affluent elites. moreover, empirical evidence linking cryonic preservation with successful post-suspension revival or meaningful digital consciousness simulation is currently speculative at best. the absence of longitudinal data and real-world applications continues to cast doubt on the practical feasibility of this emerging domain. addressing these gaps requires a comprehensive approach that combines bioethical inquiry, computational neuroscience, media theory and global sociology to define the boundaries and possibilities of continuity in a technologically augmented future. thus, the core problem centres on the fragmented understanding and uneven development of the cryonics-digital communication nexus, leaving an urgent need for empirically grounded, culturally sensitive and theoretically robust research. this study aims to explore how cryonics suspension contributes to the preservation of the structural and functional components of human consciousness, particularly focusing on the viability of long-term neural preservation techniques. it also seeks to assess the role of digital communication technologies in simulating or preserving personal identity beyond biological death, through tools such as memory archiving, artificial intelligence, and virtual representations. additionally, the study investigates how ethical and cultural contexts influence the acceptance and effectiveness of combining cryonics with digital continuity practices, recognizing that beliefs about death and identity vary across societies. finally, the research intends to identify existing gaps, empirical, conceptual and technological within current models that integrate cryonics and digital communication as pathways to achieving posthumous human continuity. continuity and consciousness continuity and consciousness represent the dependent variable in this study, serving as the outcome phenomenon being influenced by technological and biological interventions. continuity, in this context, refers to the preservation and persistence of personal identitypsychological, experiential and cognitive beyond conventional biological death. consciousness, a deeply contested concept, is broadly described here as the awareness of self and the ability to perceive, process and respond to internal and external stimuli (dehaene, 2020). within cryonics and digital communication, continuity and consciousness are theorised to transcend their traditional biological bounds through neural preservation, digital memory archiving and aibased simulations. however, the extent to which digital representations of memory can constitute or sustain "consciousness" is still under intense scientific and philosophical scrutiny (koch, 2022). these complexities make the dependent variable both empirically elusive and conceptually layered. mailto:topacademicjournals@gmail.com tel:2020 tel:2022 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the redefinition of consciousness in the age of artificial intelligence and post-biological identity raises questions about the authenticity, legitimacy and moral status of digitally sustained selves. some scholars argue that, continuity without the biological brain is merely a simulation lacking phenomenological awareness, while others scholars posit that, consciousness can be replicated through emulated neural processes, provided that memory and personality are sufficiently preserved (sandberg & bostrom, 2020). in the context of cryonics, the dependent variable is also linked to the effectiveness of preservation techniques in maintaining the brain's connectomethe structural mapping of neural connections responsible for memory and cognition. without successful preservation of this network, the notion of post-suspension continuity remains speculative. thus, continuity and consciousness serve as both the goal and the benchmark for evaluating the success of cryonics integrated with digital technologies. cryonics suspension and digital communication cryonics suspension and digital communication constitute the independent variables in this study, as they are the primary inputs influencing the prospect of continuity and consciousness. cryonics suspension refers to the process of preserving legally dead individuals at extremely low temperatures, typically using vitrification to prevent ice formation in cells, particularly brain cells (best, 2018). the objective is to maintain the structural and biochemical integrity of the brain so that, when future technologies evolve, the individual could theoretically be revived with their identity intact. the scientific feasibility of this process is still debated and critics cite the lack of a successful revival case as a significant limitation. nonetheless, cryonics is predicated on the assumption that memory and personality are functions of the brain's physical structure, which can be preserved through advanced biotechnological means (emanuel et al., 2021). digital communication technologies, including artificial intelligence, neural networks and memory archiving systems, have emerged as complementary or even alternative methods of preserving aspects of human identity. tools such as digital avatars, virtual reality simulations and cloud-based cognitive models allow for the encoding and storage of thoughts, preferences and behavioural traits (floridi, 2014). these technologies aim to create a "digital self" capable of existing and interacting in virtual environments, possibly long after the biological self-ceases to function. the increasing integration of ai in analysing and simulating brain functions suggests that, digital communication is not just a medium but also a mechanism for preserving consciousness. when paired with cryonics, digital communication technologies offer a dual pathway, biological and virtual for extending identity, rendering them critical independent variables in the study of posthumous continuity. ethical and cultural contexts ethical and cultural contexts function as the moderator variables in this research, shaping the relationship between the independent variables (cryonics suspension and digital communication) and the dependent variable (continuity and consciousness). these contexts influence public perception, regulatory policies, individual acceptance and societal implementation of both cryonics and digital immortality. ethical questions surrounding consent, personhood and the commodification of consciousness are particularly pronounced in debates about mailto:topacademicjournals@gmail.com tel:2020 tel:2018 tel:2021 tel:2014 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset posthumous revival or digital resurrection (nuffield council on bioethics, 2023). for example, the moral implications of reviving a person in a radically transformed future society where their rights, autonomy or identity might not be preserved raise significant ethical dilemmas. such concerns could weaken or strengthen the effectiveness of cryonics and digital technologies, depending on how they are addressed within different cultural and legal frameworks. culturally, beliefs about life, death, the afterlife and the soul significantly mediate how cryonics and digital continuity are understood and accepted. in many african, asian, and indigenous cultures, for instance, the idea of extending life through artificial means may conflict with traditional spiritual beliefs that emphasise natural death and ancestral continuity (obot, 2023). in contrast, western cultures often valorise individualism and scientific progress, making them more receptive to the ideals of cryonic preservation and digital legacy. these cultural dimensions moderate not only public engagement but also funding priorities, legal readiness and ethical evaluations of these technologies. therefore, ethical and cultural contexts play a crucial role in determining whether the outcomes of cryonics and digital communication will truly result in meaningful continuity and consciousness or remain speculative and inaccessible constructs. media technological determinism theory this theory is rooted in the works of marshall mcluhan (1964), who famously stated that "the medium is the message," asserting that, technological media rather than the content they convey profoundly shape human experience, perception and societal development. the theory assumes that, changes in media technology are the primary drivers of cultural and psychological shifts, effectively determining how societies evolve over time. its central tenet is that, technology, especially, communication media influences human behaviour and consciousness independently of human intent. in the context of this study, the theory suggests that, digital communication tools such as ai, virtual reality and neural simulations are not just assisting human memory and identity but are actively reshaping the very concept of continuity and consciousness. critics of the theory argue that, it overemphasises technology’s role while underestimating human agency, culture and socio-political factors in shaping media use and outcomes (peters, 2015). nevertheless, the theory remains highly relevant in this study as it provides a conceptual foundation for understanding how digital media and communication platforms serve as transformative tools in the potential extension of human identity and consciousness, especially, when integrated with cryonics technologies (chandler & munday, 2022). cybernetic ontology this theory, derived from norbert wiener's cybernetics theory (1948) and later expanded by thinkers like katherine hayles (1999), posits that life and consciousness can be understood as systems of information processing and feedback loops. the central assumption of this theory is that either organic and artificial systems, humans, machines or hybrids operate based on the continuous exchange and regulation of information. it views consciousness not as uniquely biological but as something that could, in theory, be replicated or sustained across different substrates, including digital platforms. the tenets of cybernetic ontology reject the mailto:topacademicjournals@gmail.com tel:2023 tel:2023 tel:1964 tel:2015 tel:2022 tel:1948 tel:1999 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset strict dualism of mind and body, embracing a posthumanist view that blurs boundaries between humans and machines. in relation to this study, cybernetic ontology supports the possibility of digitally encoded consciousness as a legitimate continuation of the self, offering a theoretical basis for integrating cryonic brain preservation with digital identity archiving. however, critics argue that, the theory can be reductionist, potentially overlooking the emotional, subjective and spiritual dimensions of consciousness (roden, 2015). despite these critiques, cybernetic ontology is crucial to this study’s exploration of how informational and computational models of the self might underpin post-biological human continuity in a future shaped by cryonics and digital communication technologies. empirical review cryonics suspension and consciousness preservation best (2018), in a study titled scientific justification for cryonics practice, evaluated whether cryonics suspension can preserve the essential structures of the human brain responsible for memory and consciousness. using a technical review of cryopreservation cases and cryobiological data, the study found out that, while vitrification methods have improved the physical preservation of brain tissue, there remains no empirical evidence confirming the revival or recovery of conscious states post-thaw. best’s findings support the viability of cryonics in maintaining brain integrity at a structural level, aligning with the first research objective of this study. however, a critique of the study lies in its lack of experimental or longitudinal human trials, relying instead on animal models and theoretical assumptions. compared to this study’s more integrated approach, best’s work focuses primarily on biological mechanisms without exploring the digital continuity dimension. the contrast lies in the technological scope, while the connection is the shared interest in preserving the neural foundation of consciousness. this reveals a trend in literature leaning heavily on biological viability while neglecting broader philosophical and technological implications, pointing to a gap in multidisciplinary inquiry into post-suspension consciousness. digital communication and identity preservation floridi (2014), in an influential work the fourth revolution: how the infosphere is reshaping human reality, explored how digital communication technologies transform human identity and the concept of selfhood in the digital age. the objective of the study was to examine how humans interact with and are shaped by digital systems such as ai, social media, and cloud-based memory repositories. employing a philosophical and analytical method, floridi revealed that, digital platforms are not merely communication tools but extensions of personal identity, capable of preserving aspects of individual memory and self-expression. while the study is philosophical rather than empirical, it supports the second research objective by establishing digital identity as a form of continuity. a critique is that it assumes widespread access and digital literacy without addressing technological inequity. compared to this study, floridi’s work is less focused on posthumous identity and more on living digital selves. however, both studies connect on the theme of digitally mediated identity continuity. this indicates a growing trend in literature emphasising the centrality of digital platforms in shaping modern mailto:topacademicjournals@gmail.com tel:2015 tel:2018 tel:2014 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset identities, but with a gap in empirical evidence linking these technologies to post-biological consciousness preservation. ethical and cultural contexts obot (2023), in the article transhumanist discourses in african tech ecosystems: cryonics and the ethics of digital immortality, investigated how ethical and cultural worldviews influence the perception and acceptance of cryonics and digital immortality in african contexts. using qualitative interviews and discourse analysis, the study revealed that, widespread scepticism rooted in religious, spiritual and communal philosophies that value natural death and ancestral legacy. while the study confirms that, ethical and cultural contexts significantly moderate how technologies like cryonics are received, it also shows a growing curiosity among younger, techsavvy africans. obot’s study aligns with the third objective by revealing the nuanced influence of culture on technological acceptance. however, a critique is its limited sample size and geographic scope, restricting generalizability. in contrast to this current study’s broader global framework, obot’s research provides an indepth regional perspective. the comparison indicates that, while cultural resistance is common in non-western societies, openness is increasing in digitally literate populations. the connection lies in acknowledging ethical and cultural contexts as crucial variables. this points to a literature trend focusing on techno-ethical debates in emerging societies but reveals a gap in cross-cultural comparative studies integrating both biological and digital preservation narratives. identifying empirical and conceptual gaps in integration models sandberg and bostrom (2020), in a roadmap study, whole brain emulation: a roadmap, provided a comprehensive assessment of the feasibility of digitally replicating human consciousness based on brain emulation. the objective was to evaluate the technical, computational, and philosophical challenges in scanning, modelling, and simulating the human brain. using a foresight-based methodological framework and systems modelling, the study found that while computational models are advancing, the ethical, legal and social infrastructure to support such projects is severely lacking. sandberg and bostrom’s findings directly speak to the fourth objective by highlighting significant empirical and conceptual gaps in the integration of neuroscience, ai and digital communication for consciousness preservation. a critique is the study’s overreliance on futuristic assumptions and limited engagement with cultural diversity. compared to this study, which aims to contextualize these gaps within cryonics and global digital systems, sandberg and bostrom offer a more technical, long-term vision. however, both share the concern about interdisciplinary coordination and technological maturity. this comparison reflects a literature trend focusing on theoretical frameworks and long-term aspirations, but with a gap in practical, short-term empirical models and inclusive ethical policies for near-future applications. gap identification mailto:topacademicjournals@gmail.com tel:2023 tel:2020 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the literature reviewed indicates a growing scholarly interest in the convergence of cryonics suspension and digital communication technologies as a means to preserve human continuity and consciousness beyond biological death. studies have explored the technical feasibility of neural preservation (best, 2018), the philosophical implications of digital identity (floridi, 2014), and the moderating role of cultural and ethical contexts (obot, 2023), while others have outlined theoretical models for digital consciousness replication (sandberg & bostrom, 2020). however, notable gaps persist across several dimensions. empirically, there is a lack of longitudinal data or real-life case studies demonstrating the successful integration of cryonics and digital continuity. conceptually, many studies treat biological preservation and digital identity simulation as separate domains, failing to develop cohesive interdisciplinary models. methodologically, existing research is skewed towards western contexts, with limited cross-cultural or comparative studies reflecting global ethical and technological diversity. theoretically, the debate between materialist and posthumanist views of consciousness remains unresolved, creating conflicting assumptions in emerging frameworks. these gaps point to an urgent need for integrated, cross-disciplinary studies that examine how cryonic technologies and digital communication systems can jointly shape the future of human identity and consciousness within diverse cultural, ethical and technological ecosystems. methodology this study adopts a phenomenological research methodology to explore how individuals conceptualize and experience the intersection of cryonics suspension and digital communication as pathways to posthumous continuity and consciousness. phenomenology is appropriate for investigating deep, subjective meanings and lived experiences related to abstract and emerging technological concepts. the target population consists of approximately 150 individuals globally, including cryonics practitioners, transhumanist thinkers, digital legacy developers, neuroethicists and ai technologists, who are directly engaged with or have scholarly or professional insights into human identity preservation technologies. these individuals are drawn from institutions such as the alcor life extension foundation, kriorus, academic research centres and digital innovation labs in countries like the united states, russia, germany, south africa and nigeria. from this population, a purposive sample of 20 participants was selected using expert sampling, a technique suitable for studies requiring input from individuals with specialised knowledge. data were collected through in-depth, semi-structured interviews conducted virtually via video conferencing platforms, allowing flexibility in time and geographic coverage while facilitating rich, interactive dialogue. each interview explores participants’ understanding, ethical considerations, cultural influences and expectations regarding cryonics and digital identity continuity. the data were analysed using thematic analysis, following moustakas’ phenomenological reduction steps, including horizonalization, clustering of themes, and synthesis of meanings to reveal core essences shared across participant narratives. this method ensures that complex, diverse interpretations are captured while identifying common themes that reflect global trends, ethical tensions, and conceptual frameworks. the chosen methodology and methods are justified by the exploratory nature of the study, the abstractness of the subject mailto:topacademicjournals@gmail.com tel:2018 tel:2014 tel:2023 tel:2020 tel:150 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset matter, and the need to interpret phenomena through the voices of those most intimately involved with or affected by these technologies. data presentation and analysis themes were theoretically constructed after the research objectives. themes to be identified below were constructed: preservation of consciousness through cryonics suspension; digital communication as a medium for identity continuity; ethical and cultural influences on technological acceptance; and knowledge, conceptual, and empirical gaps in integration models. they were explained and discussed below: preservation of consciousness through cryonics suspension this theme explores participants' understanding and perceptions of the extent to which cryonic technologies can preserve the structural and functional components of human consciousness, particularly focusing on neural integrity, memory retention, and the potential for future revival. “the neurological basis of consciousness preservation in cryonics relies fundamentally on preventing ice crystal formation in the brain, which vitrification technology aims to achieve. leading cryonics organizations such as alcor and the cryonics institute now routinely employ cryoprotectants like glycerol and dmso to replace intracellular water, thereby, preserving ultrastructural cellular architecture intact (alcor, 2024). this method has shown significant improvement over earlier techniques that caused microstructural damage.” “despite these advances, no human or animal has yet been revived with functioning consciousness following deep-cold preservation. a small number of mammalian brain studies (e.g., rabbit or pig models) have indicated retention of synaptic ultrastructure (mcintyre & fahy, 2015), but no electrophysiological activity or behavioural restoration has been documented. this gap underscores the enduring uncertainty around whether structural preservation translates to functional continuity.” “neuroscientists increasingly emphasize the need to map and preserve the connectome, the brain’s neural wiring diagram responsible for memory and identity. however, current cryonics protocols stop short of verifying intact synaptic connectomes. without such mapping, revival efforts lack a clear blueprint for restoring consciousness, which remains an aspirational leap rather than a validated outcome.” “bioethicists highlight this uncertainty as a major limitation: preserving tissue is not equivalent to preserving personhood. if revival is ever possible, questions about identity retention, memory fidelity, and subjective experience remain unanswered. the preservation of 'potential consciousness' may be insufficient if revived entities bear no coherent continuity with their former selves.” “from a technological perspective, the timeframe and conditions for future revival remain speculative. cryonics funders anticipate that nanomedicine, advanced brain scanning and neural nanorobots could eventually reverse damage and reintegrate memories. but these assumptions depend on technologies still at mailto:topacademicjournals@gmail.com tel:2024 tel:2015 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset early research stages, many in theoretical or prototype form. the absence of current capabilities leaves a significant research gap.” “in summary, expert views suggest that while cryonics shows potential to preserve the structural basis of consciousness, it remains unproven. the ambition to maintain personal identity through brain preservation is compelling but unverified. continued interdisciplinary research, integrating cryobiology, connectomics, neuroscience, and ethics is essential to bridge the gap between theoretical preservation and realized conscious continuity.” digital communication as a medium for identity continuity this theme examines how digital tools, such as artificial intelligence, memory archiving, and virtual simulations are perceived to contribute to the preservation or extension of personal identity beyond biological death. “modern digital communication tools are evolving into mechanisms that carry personal identity beyond life. services like hereafter ai or replika allow users to feed chat histories, voice recordings, preferences, and personality traits into ai systems to generate conversational avatars that mimic real individuals (hereafter ai, 2023). these platforms capture a form of behavioural continuity even after death.” “such digital avatars operate on machine learning models trained on personal data, creating interactive simulations that can respond to questions, display quirks, and sometimes even replicate humour or sentiment patterns. while these aren’t conscious in the neuroscientific sense, they preserve recognizable narrative aspects of identity.” “philosophers like luciano floridi argue that the infosphere comprising digital interactions, data trails, and virtual expressions is becoming as much part of self-identity as one’s physical existence (floridi, 2014). they assert that digital traces can sustain a form of posthumous presence, though this presence lacks subjective awareness.” “critics point out that such simulations may become superficial or misleading over time. without real memory recall or intentional agency, these ai-based identities risk becoming caricatures shaped by algorithmic bias or selective data input. they expose a tension between simulated continuity and authentic personhood.” “nevertheless, rapid advances in generative ai and neural network architectures suggest future avatars could integrate deeper behavioural prediction, emotional modelling, and even adaptive learning to evolve over time. combined with biometric and neurodata, these may move closer to immersive continuity, though the leap to consciousness remains hypothetical.” “thus, digital communication technologies offer emerging pathways toward preserving memory-based identity beyond biological death. they align strongly with the second research objective, yet highlight technological and philosophical limitations—specifically regarding subjective authenticity, data representation fidelity, and the boundary between simulation and sentient continuity.” ethical and cultural influences on technological acceptance mailto:topacademicjournals@gmail.com tel:2023 tel:2014 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset this theme investigates how ethical beliefs, religious values, and cultural worldviews shape individual and collective attitudes toward cryonics and digital immortality, highlighting acceptance, scepticism or resistance across different societal contexts. “ethical and cultural contexts profoundly shape how individuals and societies engage with cryonics and digital immortality. in north america and parts of europe, transhumanist ideals encouraging technological transcendence of death have gained traction, bolstered by secular humanist values and high public familiarity with identity-extension tools.” “in contrast, many non-western societies, especially in africa, asia and parts of latin america express strong religious or spiritual reservations. as observed by obot (2023), beliefs in ancestral continuity, spiritual journeys after death, and natural life cycles render cryonics and digital resurrection ethically incongruent with local worldviews.” “these cultural divides influence not only individual acceptance but policy frameworks, regulatory design and public funding. ethical concerns around informed consent, autonomy, and commodification of identity emerge, particularly, where technological access is limited to affluent elites, raising justice concerns about existential inequality.” “public scepticism often centres on violations of natural order or disrespect toward traditional beliefs. some ethical frameworks in these contexts deem attempts to ‘cheat death’ as hubristic or disrespectful toward ancestral realms. these moral intuitions persist despite growing exposure to digital technologies.” “however, younger, digitally literate populations in many societies show curiosity or openness, seeing potential benefits in legacy preservation or future resurrection. they often reinterpret or negotiate cultural belief systems in light of new digital and scientific possibilities.” “overall, experts emphasise that any global model integrating cryonics and digital continuity must consider deep cultural variance and ethical plurality. understanding these moderating contexts is essential to avoid techno cultural imposition and to promote inclusive, sensitive, and ethically robust adoption strategies.” knowledge, conceptual and empirical gaps in integration models this theme identifies perceived limitations, challenges, and gaps in current technological, empirical, and theoretical efforts to integrate cryonics and digital communication, including concerns about feasibility, accessibility and interdisciplinary collaboration. “integrating cryonics and digital communication faces major empirical gaps: there is no documented case of a revived cryonically suspended person, nor any instance where a digital avatar has achieved autonomous consciousness or self-awareness.” “conceptually, bioengineers focus on brain preservation, while ai developers build identity simulations, yet frameworks connecting physical preservation and digital continuity are rare or underdeveloped. the absence of a unified interdisciplinary model remains a key challenge.” mailto:topacademicjournals@gmail.com tel:2023 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset “technologically, although initiatives like neuralink and similar brain-computer interface projects are advancing brain scanning and neural signal recording (musk, 2023), none currently approach full mapping of the connectome or uploading consciousness. data longevity, security and interoperability remain unresolved.” “moreover, ethical and regulatory infrastructures lag behind technological ambition. questions around data ownership, digital rights of post-biological selves, revival consent and cross-jurisdictional legal status remain largely unexplored in practice.” “researchers also note a demographic bias in existing studies: western technophiles dominate, with limited cross-cultural, gender-diverse, or socioeconomic representation. this limits understanding of global attitudes, access disparities, and diverse ethical frameworks.” “hence, experts emphasise the necessity of integrated research paradigms combining cryobiology, neuroinformatics, ai ethics, and anthropology, with inclusive sampling. only through such collaborative, culturally attentive, and empirically grounded approaches can the field move beyond speculation toward meaningful models of continuity.” discussion of findings the study found out that, while cryonics suspension techniques like vitrification can preserve the structural integrity of brain tissue, there is no current scientific evidence confirming the restoration of consciousness or cognitive function after suspension, leaving the promise of continuity through cryonics largely theoretical and technologically aspirational. best (2018) provides a scientific foundation for the first finding by asserting that cryonics suspension, particularly, through vitrification, effectively preserves the structural integrity of neural tissues, though the restoration of consciousness remains speculative without empirical revival. this supports the strand of continuity as potential rather than proven, aligning with the study’s conclusion that, while structural preservation is advancing, functional recovery and conscious reawakening remain theoretical and demand rigorous scientific validation. cybernetic ontology is directly relevant to finding 1, as it conceptualizes consciousness as an informational system of feedback loops and signal processing, supporting the premise that if the brain’s neural architecture was preserved through cryonics, then the informational basis of consciousness might eventually be restored, as suggested by best (2018) and supported by connectome-focused neuroscience. the study revealed that digital communication technologies, such as ai-driven memory archives and virtual avatars are increasingly used to simulate identity and preserve memory narratives after death, though these simulations lack subjective awareness and thus, cannot fully replicate human consciousness. floridi (2014) reinforces the second finding by arguing that, digital communication technologies extend human identity into the “infosphere,” creating persistent digital selves based on stored data, interactions and virtual representations. this backs the strand that digital continuity is achievable through memory simulation and symbolic presence, also affirms the study’s position that, such identity preservation, though meaningful, does not equate to conscious awareness or authentic personhood. media technological determinism theory is relevant to finding 2, as it posits that, the medium itself here, digital communication technologies shapes human identity, mailto:topacademicjournals@gmail.com tel:2023 tel:2018 tel:2018 tel:2014 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset interaction and legacy, aligning with the finding that ai-powered simulations and digital avatars preserve a symbolic form of personal continuity beyond biological death; mcluhan’s (1964) assertion that, "the medium is the message" is echoed in floridi’s (2014) recognition of the "infosphere" as a digital extension of self. the study showed that, ethical and cultural beliefs significantly influence the acceptance and interpretation of cryonics and digital immortality, with western contexts showing more openness due to secular and individualistic values, while many african and asian societies resist these technologies based on spiritual, communal and ancestral belief systems. obot (2023) substantiates the third finding by demonstrating that, ethical and cultural worldviews, particularly, in african societies largely resist the adoption of cryonics and digital immortality due to spiritual beliefs and communal perspectives on death and legacy. this supports the study’s strand that, ethical and cultural diversity plays a critical moderating role, necessitating contextual and inclusive approaches for these technologies to gain meaningful global relevance. the theory is also relevant to finding 3, as it helps explain how societal responses to cryonics and digital immortality are influenced by media infrastructure and exposure; cultures that embrace advanced media technologies tend to accept these concepts more readily, while others with limited access or different traditions resist them, validating obot’s (2023) findings on culturally grounded scepticism. thus, the deterministic role of media in shaping technological adoption and identity construction reinforces both the simulation-based continuity and culturally moderated responses explored in the study. the study indicated that, current models integrating cryonics and digital communication suffer from major empirical, conceptual and technological gaps, including the lack of interdisciplinary frameworks, absence of real-world case applications and underrepresentation of diverse global perspectives in both research and practice. sandberg and bostrom (2020) directly align with the fourth finding by outlining the conceptual, empirical and technological limitations in current efforts to emulate or upload human consciousness, emphasising that while theoretical roadmaps exist, practical integration remains distant. this affirms the strand that the field is fragmented and underdeveloped, supporting the study’s conclusion that, interdisciplinary collaboration is essential to translate speculative frameworks into operational models of posthumous human continuity. the theory is also essential to finding 4, which highlights the lack of integration between biological and digital continuity models; cybernetic ontology, rooted in wiener’s (1948) and hayles’ (1999) view that both organic and machine systems process and transmit information, underpins the belief that human identity can be preserved across different substrates. sandberg and bostrom’s (2020) roadmap reflects this theoretical lens by advocating for the eventual emulation of the mind through computational modelling. conclusion the study explores that while cryonics shows potential for preserving the brain’s structural components, the lack of verifiable revival outcomes and unresolved scientific uncertainties about the restoration of consciousness highlight the need for further empirical research before it can be considered a reliable method of human continuity. mailto:topacademicjournals@gmail.com tel:1964 tel:2014 tel:2023 tel:2023 tel:2020 tel:1948 tel:1999 tel:2020 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the conclusion drawn is that, digital communication technologies, though effective in preserving memorybased representations of individuals, remain limited to identity simulation rather than actual consciousness preservation, thereby, offering a symbolic rather than functional form of posthumous continuity. the study establishes that, the ethical and cultural acceptance of cryonics and digital immortality is not universal, and for these technologies to gain broader relevance, they must be contextualized within diverse belief systems, social values and ethical norms that define how different societies perceive life, death and legacy. it is concluded that the integration of cryonics and digital communication for posthumous continuity remains conceptually fragmented and technologically premature, underscoring the urgent need for interdisciplinary collaboration, inclusive representation and practical innovation to move the field beyond speculative promise. this study makes a unique and original contribution to knowledge by advancing an interdisciplinary understanding of how cryonics suspension and digital communication technologies can co-evolve to redefine human continuity and consciousness beyond biological death. it creatively synthesises insights from neuroscience, communication studies, cybernetics, ethics and cultural anthropology to develop a novel framework for interpreting identity preservation in a post-biological future. the research introduces an innovative conceptual model that integrates biological preservation (cryonics) with digital memory simulation (ai, avatars, and virtual platforms), providing a new lens for analysing what it means to "remain human" in the age of digital immortality. in terms of theoretical contribution, the study deepens the application of media technological determinism and cybernetic ontology by contextualizing them within the futuristic and ethically charged debate around posthumous human identity. it extends media technological determinism by demonstrating how digital platforms shape perceptions of self and legacy, and it expands cybernetic ontology by grounding the mind-asinformation model in real-world preservation technologies. this dual-theoretical approach strengthens the philosophical and communicative understanding of identity as both material and virtual, as well as continuous across time, media and memory systems. on the level of product development, this research proposes a conceptual prototype for a hybrid identitypreservation system, one that combines cryonic neural preservation with digitally stored, ai-enhanced personality and memory archives. such a model, when developed collaboratively with neuroscientists and tech firms, could inform future digital legacy platforms, brain-computer interface systems and even policy guidelines for ethical digital resurrection tools. this contributes practically to the design of ethically-informed, scientifically plausible digital continuity technologies. these contributions directly connect to the current research goals, which include examining the potential of cryonics to preserve consciousness, assessing the role of digital communication in simulating identity, analysing the moderating effect of cultural ethics and identifying interdisciplinary gaps. the originality and innovation in proposing a unified theoretical and practical model for human continuity address the central aim mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset of the research: to reimagine continuity and consciousness in humanity’s future through an empirical and conceptual merger of biological and digital preservation systems. through this, the study not only fills a knowledge gap but also offers a forward-looking pathway for future scholarship and ethical technological development in posthuman identity preservation. recommendations following these observations, the following have been proposed. 1. the scientific research institutions such as the alcor life extension foundation, cryonics institute and global neuroscience laboratories should invest in advanced, long-term studies on brain connectome preservation and revival to validate the functional outcomes of cryonics suspension. 2. technology companies like hereafter ai, openai, and digital legacy platforms should collaborate with cognitive scientists and ethicists to develop more ethically grounded and cognitively accurate digital identity models that move closer to preserving authentic personal continuity. 3. the global ethics councils, such as unesco’s bioethics committee and national cultural institutions, engage local communities and religious bodies in inclusive dialogue to shape culturally sensitive frameworks for adopting cryonics and digital continuity technologies. 4. universities, multidisciplinary think tanks, and policy-making bodies should lead collaborative research and innovation programs that integrate cryobiology, ai, neuroethics, and anthropology to bridge the practical and conceptual gaps in posthumous human continuity technologies. references alcor life extension foundation. (2024). alcor faq. https://www.alcor.org/ best, b. (2018). scientific justification for cryonics practice. cryonics institute. chandler, d., & munday, r. (2022). digital afterlives: death, identity and social media. sage publications. dehaene, s. (2020). consciousness and the brain: deciphering how the brain codes our thoughts. penguin random house. emanuel, r., strout, j., & khan, s. (2021). neural mapping and the future of memory preservation. neuroethics journal, 14(2), 115–129. floridi, l. (2014). the fourth revolution: how the infosphere is reshaping human reality. oxford university press. mailto:topacademicjournals@gmail.com tel:2024 https://www.alcor.org/ tel:2018 tel:2022 tel:2020 tel:2021 tel:115 tel:129 tel:2014 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset gorman, m. (2022). legal and ethical challenges in cryonic preservation: an australian perspective. bioethics quarterly, 38(3), 221–237. hayles, n. k. (1999). how we became posthuman: virtual bodies in cybernetics, literature, and informatics. university of chicago press. hereafter ai. (2023). digital legacy platform overview. https://www.hereafter.ai/ kaku, m. (2021). the god equation: the quest for a theory of everything. doubleday. koch, c. (2022). the feeling of life itself: why consciousness is widespread but can't be computed. mit press. mcintyre, r. l., & fahy, g. m. (2015). brain preservation and the connectome. cryobiology, 71(1), 1–9. mcluhan, m. (1964). understanding media: the extensions of man. mcgraw-hill. more, m., & vita-more, n. (eds.). (2013). the transhumanist reader: classical and contemporary essays on the science, technology, and philosophy of the human future. wiley-blackwell. musk, e. (2023). neuralink and the future of brain-computer interfaces. neuralink presentation, december 2023. nuffield council on bioethics. (2023). neurotechnologies and human enhancement: ethical perspectives. nuffield reports. obot, e. a. (2023). transhumanist discourses in african tech ecosystems: cryonics and the ethics of digital immortality. journal of african technological futures, 9(1), 54–69. peters, j. d. (2015). the marvellous clouds: toward a philosophy of elemental media. university of chicago press. pratt, h., ellis, j., & mohr, c. (2023). artificial intelligence and neural simulation: toward post-biological identities. technoscience and society, 7(4), 348–366. roden, d. (2015). posthuman life: philosophy at the edge of the human. routledge. sandberg, a., & bostrom, n. (2020). whole brain emulation: a roadmap. journal of evolution and technology, 30(1), 1–32. mailto:topacademicjournals@gmail.com tel:2022 tel:221 tel:237 tel:1999 tel:2023 https://www.hereafter.ai/ tel:2021 tel:2022 tel:2015 tel:1964 tel:2013 tel:2023 tel:2023 tel:2023 tel:2023 tel:2015 tel:2023 tel:348 tel:366 tel:2015 tel:2020 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wiener, n. (1948). cybernetics: or control and communication in the animal and the machine. mit press. mailto:topacademicjournals@gmail.com tel:1948 academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset structural characteristics of high-density polyethylene matrix composites enhanced by open-air and furnace rice husk ash 1dennis o. omambia., 1peter k. kamweru, 2john m. gichumbi, and 2faith g. ndiritu 1department of physical sciences, faculty of science, engineering and technology chuka university, kenya. 2department of physics, faculty of science, egerton university egerton university, kenya. doi: https://doi.org/10.5281/zenodo.10592549 abstract: in this work, rice husks ash (rha) was introduced to pure and recycled high density polyethylene (hdpe) matrix, at varying ration (0-50%) to formulate rice husks ash high density polyethylene (rhahdpe) composite. rha was obtained by burning fresh rice husks either by open-air burning (orha) or furnace calcination at 700°c (frha). the composite samples were made by melt-mixing the hdpe in an oven at a temperature of 150°c and adding different percentages of rha in presence of maleic anhydride compatibilizer. fourier transform infrared spectroscopy (ftir) and scanning electron microscopy (sem) were carried out to determine the structural properties of the samples, and both suggest occurrence of composting chemical changes. for all rha-hdpe samples, a broad band was noted between 970-070cm-1. this was highly contributed by the rha and associated to si-o-si stretching modes. other peaks are associated with si-o-c interaction and o-si-o bending vibrations in the samples. scanning electron microscopy (sem) micrographs for hdpe indicated a smooth and uniform surface with a number of voids. on addition of rha, the particles filled these voids making the sample surface rough. this roughness is seen to increase with increased percentage of rha. the studies conclude that the cheaply obtained orha is as good as the frha in making rha-hdpe composite. keywords: rha-hdpe composites, maleic anhydride compatibilizer, rice husks, rice husks ash, fourier transform infrared spectroscopy (ftir, scanning electron microscopy (sem). introduction high-density polyethylene (hdpe) is a thermoplastic 1995; zhang et al., 2004), it has found diverse polymer produced from the monomer ethylene, and one applications that include household appliances, of the most important commercial polyolefin. due to its automobiles, wiring and cables, aeronautics and excellent combination of properties (diraddo and laroche, packaging. however, hdpe and its wide use have drawbacks that emanates from its poor weatherbility (khan and ahmed, 2003; zebarjad et al., 2006). to improve hdpe properties and reduce cost, fillers such as natural fibers (lei et al., 2007), sisal fibers (li et al., 2008), kenaf fibers (salleh et al., 2014) back fibers (yemele et al., 2010) can be blended with hdpe amongst others as in the reviewed in various literature (sarasini and fiore, 2018; dashtizadeh et al., 2017; ng et al., 2020). rice husks (rh), are a byproduct of rice milling process and produced in large quantities. for instance, the world rice production was approximately 782 million tonnes in 2018 (fao, 2020). rice husks constitute 20 % of rice paddy, and its composition is as follows: cellulose (50%), lignin (25–30%), silica (15– 20%), and moisture (10–15%). bulk density of rice husk is low and lies in the range 90–150 kg/m3 (singh, 2018). these proportions may however change depending on the geographical conditions, rice variety, methods of sample preparation and analysis among mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset others (chandrasekhar et al., 2003; johar et al., 2012). rice husk has low commercial value, and when burnt to extract energy, the ash is of low value and most of it ends up in landfills (govindarao, 1980; shivam et al., 2019). this among other reasons has attracted research interests to use ash obtained from burning rice husks as fillers in thermoplastic polymers (zaaba and ismail, 2019). the use of rha as a filler in hdpe offers a twopronged advantage, that is, it reduces pollution of both waste rice husks and hdpe (kohl et al., 2020; van thanh et al., 2020), and it ultimately leads to production of a novel material with its properties enhanced (abdul azam et al., 2020; collazo-bigliard et al., 2019). this was the motivation of this study. formulation of rha-hdpe composites and their characterization has been undertaken in some studies in different ways. for instance, in their study on rice husk ash as a valuable reinforcement for high density polyethylene, ayswarya et al. (2012) were able to formulate rha-hdpe composites of different percentages. compatibilization was first done where the compatibilizer (ma-g-hdpe) was a grafting reaction between maleic anhydride (ma) and hdpe with the help of dicumyl peroxide (dcp) initiator at 145 . the study amongst others like, ginting et al. (2017) and daramola et al. (2015), did not consider higher percentages of rha neither did they consider the properties of the composites made by rha from uncontrolled burning of rice husks which is a cheaper way of obtaining rha. another study conducted by dominic et al. (2014) on rice husk silica as an efficient biofiller in high density polyethylene, pretreatment of rice husks with hcl was first done followed by calcination in a furnace at 650 for 6h to get silica. hdpe was then allowed to melt at 145 for two minutes and then varying amounts of rhs (0.53 wt%) were added and mixed to form the composite. the test specimens were then cut from the cooled blends. sem micrographs of pure hdpe showed a number of voids. on addition of rhs, the rhs particles occupied the voids uniformly providing more reinforcement. the wavy texture of hdpe-rhs surface showed signs of greater energy absorption. ftir analysis of the samples was not conducted as well as considering rha instead of rhs. ginting et al. (2014) in his study on preparation and characterization of rha as a filler material into nanoparticles of hdpe thermoplastic composites, the composites were made by mixing hdpe, nanoparticle rha and pe-g-ma in different percentages of hdpe (100, 95, 93, 91, 89, 87 wt %). a constant amount of compatibilizer (3% wt) was used. a different study was done by tong et al. (2014) on mechanical and morphological properties of recycled hdpe composite using rice husk filler. the rh fibers were first dried in an oven to reduce the moisture content. the compounding of the fibers and recycled hdpe with the coupling agent (ma-g-hdpe) was done. five different fiber loadings (0, 10, 20, 30 and 40% wt) were used. for structural characterization of the samples, sem micrograph image for 0% wt rh fiber showed no clear gaps in between the recycled hdpe particles. this proved that recycled hdpe was well mixed during the extrusion process. for 20% wt rh fibers, sem image showed no clear gaps between rh fibers and recycled hdpe matrix indicating good interface bonding. for 40% wt rh fiber, the fibers were perfectly attached to the matrix and were evident that the fibers were strongly imbedded in the matrix. ftir analysis was not carried out. also, rha was not considered in preparation of the samples. parvinzadeh et al. (2010) studied on surface characterization of polyethylene terephthalate/silica nanocomposites. in their study, an atr-ftir was done on the samples. it was found that there was a broad band at 3200-3400 cm-1, intense bands at 3000-3200 cm-1 and bands at 1600-1800 cm-1. these bands were related to intermolecular o-h bonds, ch2 asymmetric stretching and c=c or c=o stretching vibrations. the –oh stretching vibrational peak became broader at 3200-3400 cm-1 band due to hydrogen bonds. this was for the hydrophilic nanosilica incorporated into pet matrix. other sharp bands at 1400-1600 cm-1 and 950-1250 cm-1 were assigned to c=c stretching and c-h in plane bending of benzene rings. it was also noted that on addition of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset hydrophilic nanosilica into the pet matrix, the o-h intermolecular bonds and ch2 stretching vibrations were intensified. a more intense band was also noted at 10001200 cm-1 related to si-o-c interactions in the pet/hydrophilic nano-silica composites. sem micrographs indicated that the pet had a smooth and uniform surface. on adding nano-silica particles to the matrix, nano-silica particle-particle and nano-silica particle-pet chain interactions led to formation of agglomerates on the surface of pet composites. this led to increased surface roughness of the composites. hdpe and rha were not incorporated in this study. the aim of this study was to composite rha and hdpe the injection hole. (both from pellets and packaging containers). in this study however, it is sought to obtain rice husks in two ways, that is, through open air burning, which is cheap but mostly results to rha with amorphous silica, and secondly, through controlled furnace calcination that would prove expensive but results to crystalline silica in the ash when right temperature conditions are chosen. the author sought to compare the properties of the composites made from hdpe that is recycled from old used packaging containers, and pure hdpe pellets obtained from plastic industries in nairobi, kenya using fourier transform infrared spectroscopy (ftir) and scanning electron microscopy (sem) materials and methods materials hdpe was obtained in two ways; first as hdpe pellets from industries and also in form of hdpe packaging containers collected from chuka municipality dumpsites in tharaka nithi county, kenya. pure hdpe has a melt flow index of 16 g/10 min (190 /2.16 kg) and a melting temperature range of 130-160 (dominic et al., 2014). other chemicals used were maleic anhydride and hydrogen peroxide obtained from sigma aldrich. rha was obtained open air burning (orha) and furnace (frha) calcination at 700 . rha (% ) hdpe (%) 0 5 10 100 95 90 25 35 75 65 50 50 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset methodology compatibilization the compatibilizer (ma-g-hdpe) was made by melt mixing hdpe and maleic anhydride (ma) in the ratio 90:10 with the help of hydrogen peroxide (h2o2) initiator (6% wt) in the molten state. it was allowed to solidify and then used in the preparation of rhahdpe blends. this followed a modified procedure as done by ayswarya et al. (2012) and montanheiro et al. (2016). preparation of the hdpe-rha composite samples collected from the dumpsite were heavily washed and allowed to dry to avoid contamination of the samples; it was cut into small pieces then melted as follows. hdpe was allowed to melt in an oven at a temperature of 150 for 20 min then varying amounts of rha were added as indicated in table 1 and a constant amount of compatibilizer (consisting of 15 % of the weight of the total blend) was blended with hdpe. the mixture was mechanically stirred to ensure a homogenous mixture. exact masses of rha and hdpe were measured using an analytical balance. the molten mixture was then allowed to cool to room temperature after being injected into the designed metallic mold chamber, whose design and dimensions are shown in figure 1. the injection was made easier using a designed metallic syringe designed as shown in figure 2. after cooling, it was then cut into samples to be used for the different characterizations. structural characterization this was determined following the method of mohamad (2007) using fourier transform infrared radiation (ftir). the ftir spectra for the samples were recorded on an atr perkin elmer a100 spectrometer. the resolution was 4 cm-1 and each sample was scanned four times at a range of 4000-380 cm -1. morphology and particle size determination followed a modified procedure obtained from ghasemi and younesi (2011), using zeiss ultra plus mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2. plunger for injecting molten hdpe-ma-rha mixture. figure 3. ftir spectra of pure hdpe pellets. scanning electron microscopy (sem) operated at 5 kv. the prepared samples were first sprinkled uniformly over an adhesive tape and spatter coated with a thin layer of gold, and an electron acceleration voltage of 20 kv was applied. results and discussion ftir spectra of pure hdpe and recycled hdpe the ftir spectra of pure hdpe and recycled hdpe are shown in figures 3 and 4, done for wavenumbers between 4000 cm-1 and 380 cm-1. the peaks for pure and recycled hdpe were similar. there are two similar prominent sharp peaks for the two types of hdpe between 2914 cm-1 and 2849 cm-1 showing that they have the highest transmittance of ir at this region. the other peaks are also in close range to each other as seen in the spectra for both types of hdpe (lin et al., 2015). during manufacture of plastic products there are many additives added, mostly dependent on the polyolefin type figure 5. ftir spectra of orha and frha. and end use of the product. luckily as outlined in a study by hahladakis et al. (2018), stabilizers, antioxidants and uv stabilizers additives are used in lower quantities or none in polyethylene products (hdpe and ldpe). it gives assurance that the hdpe obtained from recycling doesn’t differ much from pure hdpe. this was similar results to the study by hadi et al., 2014. it is now expected, similar to a study by adhikary et al. (2008), that the properties of the composites based on recycled hdpe will be equivalent to those based on pure hdpe. ftir spectra of open air burnt and furnace calcined rha ftir spectra of orha and frha are shown in figure 5. 35 % frha. the broad band evident in orha peaking at 3398.87 cm-1 represents the silinol oh groups and surface adsorbed water (ren et al., 2013; zhang et al., 2013), and it is absent in frha. this was shown in other studies (deshmukh et al., 2012). another unique and differentiating band in orha is the band peaking at 1603.15, representing c=c mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset stretching of aromatic carbon (chuai et al., 2001; khalil et al., 2001; prachayawarakorn and yaembunying, 2005). the peaks between 1200 cm-1 and 700 cm-1 represents the vibration modes of the si-osi network (della et al., 2002). the peaks at 1051.24 cm-1 for frha and 1052.95 cm-1 for orha show the silixone groups si-o-si (pongdong et al., 2015). the band at 443.24 cm-1 and shifted to 447.53 cm-1 is associated to si-o bending mode (della et al., 2002). these peaks show the presence of sio2 with a slight peak shifting that matches earlier studies. this indicates the presence of nano structured sio2 in the rha, as expected. figure 4. ftir spectra of recycled hdpe. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ftir spectra of the rha-ma-hdpe composites figure 6 to 9 shows the spectra of rha and compatibilized hdpe-rha composites for different proportions of rha and the two different rha preparation methods. the ftir spectra broadly shows peaks around the following larger bands, 995.08-1068.37 , , 1324.86-1473.35 2048.03-2074.07, 2821.35-2914.88 and 3659-3698.80 cm-1. there is a great similarity in the peaks was noted for samples with 5, 10 and 35% frha. additional peaks exist at 875-450 cm-1 for the rhamahdpe made composited of 50% orha is evident. these are the peaks present in the rha before compositing. this could mean that most of the rha at this percentage mix ratio has not blended well in the hdpe matrix. it could have agglomerated into pockets within the hdpe without forming a uniform blend. however, other peaks have slightly shifted for the rha-hdpe samples compared to those of pure ash and pure hdpe indicate changes in structure. this is due to formation of new bonds between the –oh and si-o-si groups in the rha and –ch group in the hdpe. the peaks between, 3655.41-3708.44 cm-1 in the sample with 5, 10 and 35% rha (both orha and frha), show the presence of o-h group in the rha arising from silanol functional groups. there is a broad band at 3599.19 cm-1 for 25% frha-recycled hdpe, 3567.78 cm1 -1 for 25% open-air rha-pure hdpe, 3482.80 cm for 35 % orha. 50% frha-recycled hdpe, 3436.34 cm-1 for 50% openair rha-recycled hdpe and 3418.08 cm-1 for 50% openair rha-pure hdpe. these bands are related to intermolecular o-h bonds. the sharp peaks at 2848.03 cm1 and 2914.99 cm-1(100% recycled hdpe) which shift slightly to 2848.08 and 2914.92 cm-1 (100% pure hdpe) appear as one broad band between 2808.81-2914.88 cm1 . this is for all 5, 10 and 35% rha except for the 35% open-air rha-pure hdpe where it appears between 2872.45-2986.23 cm-1. these intense broad peaks are associated with ch2 asymmetric stretching. the broad peak is also associated with –oh group and chemically absorbed water in the rha. the prominent peak at 2074.07 cm-1 which shifts to 2073.10, 2034.59, 2019.92 and 2028.35 cm-1 (5, 10 and 35% rha spectra) is related to c=c or c=o stretching vibrations. other smaller peaks mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset were noted between 1500-1800 cm-1 for 25% frha-pure and recycled hdpe, 50% frha-recycled hdpe, 50% orha-recycled hdpe and 50% orha-pure hdpe. these were also associated with c=c or c=o stretching vibrations. between, 1400-1500 cm-1 there appeared sharp peaks which were much longer for 0, 25 and 50% rha. a broad band with slightly sharp peaks at the end appeared between, 1300-1350 cm-1. these are associated with c-h in plane bending. the broad band between 970-1090 cm-1 for all rha-hdpe samples is associated with si-o-si stretching modes. other smaller sharp peaks appeared between 750-910 cm-1 and much sharper and longer peaks between 700-730 cm-1 for the 25% and 50% rha samples. these are related to si-o-c interactions in the rha-hdpe blends. for these samples, a broad peak is also noted between, 440-470 cm-1. it is highly contributed by the rha and is associated with osi-o bending vibration in the ash samples. sem analysis figure 10 shows the sem micrographs of hdpe both pure and recycled at a higher magnification of 20 kx. there is evidence of ‘smooth’ homogeneous matrix in both, but with voids that could easily be filled by filler materials. figure 11 shows sem micrographs for 25% 35 % frha. rha-hdpe samples for various magnifications. there is evidence of agglomeration of rha on the surface of hdpe composites. lower magnification spectra for these samples show distinction between rha particles and hdpe particles. rha particles of irregular shapes and non-uniform distribution are also observed. voids are also seen on the surface indicating its roughness. the surfaces also tend to appear smooth as the magnification increases. there is a homogenous dispersion of rha particles in the matrix showing uniform composition of rha-ma-g-hdpe. due to its low percentage in these composites, rha could not fill all the voids in the hdpe. also, at this magnification there appear no clear gaps between the rha and hdpe matrix indicating good interface bonding. figure 12 shows micrographs for 50% rha-hdpe composites (magnification 20000×). the micrograph shows thermal eradication of the organic matter in the rice husk ash by forming residual pores within the ash sample. this is an ultimate indicator of porous active silica with large internal surface area. the color of the silica is grey, with loose flakes showing plate-like morphology (farooque et al., 2009). conclusion ftir analysis for the rha-hdpe samples showed that there were structural changes due to addition of rha into the hdpe. it was also observed that the sharp peaks in the hdpe converted to broad peaks in these samples. all the 5% rhahdpe blends had a common transmittance at 2074.07 cm-1 which shifted to 2073.10 cm-1 for the 10% frha-pure hdpe. the 25% rha-hdpe spectra were similar to those of hdpe with very slight shifts in peaks. for the 50% rha-hdpe blends, the spectra appeared as a combination of both the rha spectra and hdpe spectra. this meant that they contributed equally to the structure formation. in terms of functional groups, sharp peaks appeared between 3655.41-3708.44 cm-1 for the 5, 10 and 35% rha samples showing the presence of o-h group in the rha arising from silanol molecules. broad bands are seen to appear in some of the 25% rha and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 9. ftri spectra for orha-ma-hdpe (recycled) composites (i) 5 % orha (ii) 10% orha and (ii) 35 % orha. figure 10. sem micrographs for hdpe for a. pure b. recycled. 50% rha blends. these are related to intermolecular oare associated to ch2 asymmetric stretching, -oh group h bonds. some of the sharp peaks in hdpe appear as a and chemically absorbed water in the ash. broad band in the 5, 10 and 35% rha samples. these sharp peaks between, 1400-1500 cm-1 were observed mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 11. sem micrographs for 25% rha-ma-g-hdpe a. magnification at 25 x b. magnification at100 x c. magnification at 1 kx d. magnification at 5 kx e. magnification at 10 kx f. magnification at 20 kx. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 12. sem micrographs for 50% rha-hdpe samples (magnification 20000×) for orha with a. pure hdpe, b. recycled hdpe and for frha c. pure hdpe and d. recycled hdpe. for the 0, 25 and 50% rha samples. these are related to c-h in plane bending of benzene rings. sem analysis for the rha-hdpe samples indicated that the surface for the 100% hdpe initially appeared smooth and uniform with a wavy texture. on addition of different percentages of rha, sem indicated that the surface texture for the samples roughens as the rha percentage increases. rha fills the voids in the hdpe making it to appear rough. also, different magnifications show different surface textures for the same sample. therefore, production of the orha is cheaper and has almost similar or better properties as compared to industrial made which is expensive and much involving. the production of orha through this method will also help control the pollution caused by rha ash as sometimes the ash lacks deposition sites ending up becoming a menace in the society. the reinforcement of the hdpe with the orha is predicted to improve the mechanical properties of the hdpe. this study recommends the use of more equipment in the structural analysis of the composites. also, specific and different temperatures can be considered especially for the frha. other percentages of rha can also be used to make more samples for more detailed analysis. further studies on the mechanical properties are encouraged. conflict of interests the authors have not declared any conflict of interests references abdul azam fa, rajendran rnr, yuhana ny, mohd rna, ahmad s, sulong ab (2020). fabrication of porous recycled hdpe biocomposites foam: effect of rice husk filler contents and surface treatments on the mechanical properties. polymers 12(2):475. adhikary kb, pang s, staiger mp (2008). dimensional stability and mechanical behaviour of wood–plastic composites based on recycled and virgin high-density polyethylene (hdpe). composites part b: engineering 39(5):807-815. ayswarya ep, francis kv, renju vs, thachil et (2012). rice husk ash–a valuable reinforcement for high density polyethylene. materials and design 41:1-7. chandrasekhar sathy, satyanarayana kg, pramada pn, raghavan p, gupta tn (2003). review processing, properties and applications of reactive silica from rice husk—an overview. journal of materials science 38(15):3159-3168. chuai c, almdal k, poulsen l, plackett d (2001). conifer fibers as reinforcing materials for polypropylene based composites. journal of applied polymer science 80(14):2833-2841. collazo-bigliardi s, ortega-toro r, chiralt a (2019). improving properties of thermoplastic starch films by incorporating active extracts and cellulose fibres isolated from rice or coffee husk. food packaging and shelf life 22:100383. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset daramola oo, oladele io, adewuyi bo, sadiku r, agwuncha sc (2015). influence of submicron agro waste silica particles and vinyl acetate on mechanical properties of high density polyethylene matrix composites. west indian journal of engineering 38(1). dashtizadeh z, abdan k, jawaid m, khan ma, behmanesh m, dashtizadeh m, ishak m (2017). mechanical and thermal properties of natural fibre based hybrid composites: a review. pertanika journal of science and technology 25(4):1103-1122. della vp, kühn i, hotza d (2002). rice husk ash as an alternate source for active silica production. materials letters 57(4):818-821. deshmukh p, peshwe d, pathak s (2012). ftir and tga analysis in relation with the% crystallinity of the sio2 obtained by burning rice husk at various temperatures. advanced materials research 585:7781. trans tech publications ltd. diraddo rw, laroche i (1995). physical properties of virgin hdpe and recycled polymers. plastics, plastics, rubber and composites processing and applications 4(24):197-200. dominic cdm, begum pms, joseph r, jose ar (2014). rice husk silica-efficient bio filler in high density polyethylene. international journal of advanced scientific and technical research 4(2):561-569. farooque kn, zaman m, halim e, islam s, hossain m, mollah y a, mahmood aj (2009). characterization and utilization of rice husk ash (rha) from rice mill of bangladesh. bangladesh journal of scientific and industrial research 44(2):157-162. ghasemi z, younesi h (2011). preparation and characterization of nanozeolite naa from rice husk at room temperature without organic additives. journal of nanomaterials p 50. ginting em, bukit n, frida e (2017). preparation and characterization of nano composites hdpe blend with rice husk ash nanoparticles. international journal of chemtech research 10(13):348-356. ginting em, wirjosentono b, bukit n, agusnar h (2014). preparation and characterization of rice husk ash as filler material into nanoparticles on hdpe thermoplastic composites. journal chemistry and materials research 6(7). govindarao vmh (1980). utilization of rice husk: a preliminary analysis. journal of scientific and industrial research 39(9):495-515 johar n, ahmad i, dufresne a (2012). extraction, preparation and characterization of cellulose fibres and nanocrystals from rice husk. industrial crops and products 37(1):93-99. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 9, issue 1; january february 2024; issn: 2837-2964 impact factor: 6.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset hadi ja, najmuldeen fg, ahmed i (2014). quality restoration of waste polyolefin plastic material through the dissolution-reprecipitation technique. chemical industry and chemical engineering quarterly 20(2):163170. hahladakis jn, velis ca, weber r, iacovidou e, purnell p (2018). an overview of chemical additives presents in plastics: migration, release, fate and environmental impact during their use, disposal and recycling. journal of hazardous materials 344:179-199. khalil ha, ismail h, rozman hd, ahmad mn (2001). the effect of acetylation on interfacial shear strength between plant fibres and various matrices. european polymer journal 37(5):1037-1045. khan jh, ahmed n (2003). photo-oxidative degradation of recycled, reprocessed hdpe: changes in chemical, thermal and mechanical properties. bulgarian journal of physics 30(3-4):158-169. kohl jg, kohl ag, licea-claverie a, zizumbo-lopez a, jayasinghe r, ashokcline m, baillie c (2020). mechanical and thermal characterization of as-received recycled polyethylene filled with rice husk and their relationship to the end use of these composites. polymer-plastics technology and materials 59(13):1463-1472. lei y, wu q, yao f, xu y (2007). preparation and properties of recycled hdpe/natural fiber composites. composites part a: applied science and manufacturing 38(7):1664-1674. li y, hu c, yu y (2008). interfacial studies of sisal fiber reinforced high density polyethylene (hdpe) composites. composites part a: applied science and manufacturing 39(4):570-578. lin jh, pan yj, liu cf, huang cl, hsieh ct, chen ck, lou cw (2015). preparation and compatibility evaluation of polypropylene/ high density polyethylene polyblends. materials 8(12):8850-8859. mohamad fzc (2007). performance of recycled high density polyethylene (hdpe)/rice husk composite injection grade in thermoforming process. montanheiro tlda, passador fr, oliveira mpd, durán n, lemes ap (2016). preparation and characterization of maleic anhydride grafted poly (hydroxybutirate-co-hydroxyvalerate)–phbv-g-ma. materials research 19(1):229-235. ng wk, johar m, israr ha, wong kj (2020). a review on the interfacial characteristics of natural fibre reinforced polymer composites. interfaces in particle and fibre reinforced composites pp. 163-198. parvinzadeh m, moradian s, rashidi a, yazdanshenas me (2010). surface characterization of polyethylene mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the impact of material management practices on performance of building construction sites in selected tertiary institutions in cross river state, nigeria enebe eucharia chika. and chukwuenye agatha tochukwu department of quantity surveying, enugu state university of science and technology, enugu doi: https://doi.org/10.5281/zenodo.15624836 abstract this work is titled the impact of material management practice on building construction sites in tertiary institutions in cross river state. the aim of this study is to evaluate the impact of material management practices on building construction sites in selected tertiary institutions in cross river state with a view to enhancing effective and efficient management of materials in building construction projects. the objectives are; to identify the causes of ineffective material management process to the construction project delivery; to evaluate the impact of material mismanagement in the building construction sites. the study adopted stratified random sampling techniques, 200 copies of questionnaire were given to respondents drawn from a population of 432. this study adopted survey research design using questionnaire as instrument for data collection and bill of quantities. the findings of the study reveal that the causes of ineffective material management process to the construction project delivery in tertiary institution in cross river state includes; incompetency of the project manager; design error; loss of fiancé; ineffective construction manager; poor planning; lack of pre and post investigation under design and improper supervision; varied labour equipment; lack of legal penalty to offenders and rush work. finally, the study indicates that cost has a positive effect with construction delivery in tertiary institutions in cross river state. time has a positive relationship with construction delivery in tertiary institutions in cross river state. quality has positive relationship with the construction delivery in tertiary institutions in cross river state. this implies that a unit increase in cost, time and quality will lead to increase in construction delivery in tertiary institutions in cross river state. the study recommends that each management techniques has its own peculiarity in term of the pretender and post tender activities and processes, division of risks between client and contractors, and the effectiveness of project monitoring and control. keywords: material management, building construction, tertiary institutions, project delivery, cross river state mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset introduction construction material constitutes a major cost component in any construction project. the cost of materials may be 50% to 70% of the total construction cost depending on type of projects (patil and pataskar, 2013, gulghane and khandve, 2015). several researchers provided different definitions for material management, therefore different definitions can be found in different references but kanimozhi and latha (2014), define materials management as a process for planning, executing and controlling field and office activities in construction. zeb, malik, nauman, hanif, and amin (2015) also define material management as a procedure for executing, planning, and controlling site activities in the construction project(s). according to ramus and birchallin (2020), the causes of losses to contractors may arise from any one of the following: inefficient deployment of resources; excessive wastage and theft of materials; plant being allowed to stand idle or under-utilized; adverse weather or working conditions; and under-pricing of tender documents by assumptions in regard to labour times, types and sizes of plant which do not equate with the realities of the construction work. the success of a project is judged by meeting the criteria of cost, time, safety, resource allocation, and quality as determined by the owner (viator, 2020). the purpose of construction project management is to achieve goals and objectives through the planned expenditure of resources that meet the project’s quality, cost, time, scope, and safety requirements. the construction manager must control, deflect, or mitigate the effects of any occurrence or situation that could affect project success. the major tasks in construction management include planning, organizing, scheduling, implementing, managing, monitoring, controlling, and tracking construction projects. it is essential therefore, for construction activities to be accomplished successfully in an effective and efficient way. this requires various strategic and management capabilities such as material management. material management according to oyeoku (2011) is defined as a process which involves grouping the business functions relating to the inflow and interplant movement of materials under a head who is in a position to coordinate and correlate individual departmental decisions in a manner which results in the most efficient allocation of organizations resources. unfortunately, material management in construction process has recently been neglected and this has undoubtedly led to huge amount of material waste while executing construction projects. obiegbu (2012) lamented that material wastage on construction site has become a canker worm in nigerian construction industry. this problem according to obiegbu (2012) has negatively affected the performance of many projects in nigeria. in nigeria, many have expressed concern over poor materials management and its impacts on the execution of construction projects. onukwube (2010) lamented that poor material management can result in substantial, but avoidable financial loss during construction. it is pertinent to mention that there are grave consequences that could result from poor materials management, which could result in insufficiency of material for production on site, forcing contractors to produce non-conforming products. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset on the basis of the above, this research is an attempt to explain the impact of material management issues on building projects in university of calabar (unicar), federal college of education obudu and cross river state university of technology (crutech) and college of education, akampka. statement of the problem it is however fast becoming a norm in construction sites that the allowable waste is far exceeded by the actual waste on construction sites. theft, vandalism, high interest rates, and improper planning make contractors in the construction industry to fall short of their anticipated profit margins in their projects. there is no established construction material management system in tertiary institutions in obudu cross river state (okanume, 2021). the materials management practices by the contractors in the institution are performed on a fragmented basis with unstructured communication and no clearly established responsibilities between the parties involved. this fragmentation creates gaps in information flow, which affects the decision making process and lead to delays in material ordering and receiving, among other problems (thomas and okanume, 2021). current manual materials management and control procedures are unsatisfactory as they are labour intensive, inaccurate, and error prone. the implication leads to waste and surplus of materials, delays, decrease in productivity and lack of up-to-date and real-time information (navon, 2021). considering the construction firms in tertiary institutions in cross river state, it appears that the managers or perhaps the contractors lack competencies required of contemporary construction firms for effective material management thereby resulting in huge amount of material waste (viator, 2020). the resultant effect of the poor material management in the construction process by these construction firms leads to poor performance in terms of their service delivery. no research has been conducted to investigate the materials management issues on building project of contracting companies in tertiary institutions in cross river state. this study, has become pertinent to explore the impact of material mismanagement on construction sites by these firms for objective remedial actions. aim and objectives the aim of this study is to evaluate the impact of material management practices on building construction sites for improving the performance of building projects executed in selected tertiary institutions in cross river state. the objectives of the study are: 1. to evaluate the impact of material mismanagement in the building construction sites in selected tertiary institution in cross river state. 2. to identify the causes of ineffective material management process to the construction project site in selected tertiary institution in cross river state. 1.4 research question the following research questions will guide the study: 1. what impact does material mismanagement have on building construction sites in selected tertiary institution in cross river state? mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2. what are the causes of ineffective material management process to the construction project delivery in selected tertiary institution in cross river state? statement of hypothesis h0: there is no significant relationship between factors affecting material management and effective building construction project delivery. literature review conceptual literature concept of construction industry construction industry plays an important role in socio economic development of any nation. the activities of the construction industry have a lot of significance to the achievement of national socio-economic development goals of providing infrastructure, sanctuary and employment. this also includes hospitals, schools, townships, offices, houses and other buildings; urban infrastructure (including water supply, sewerage, drainage); highways, roads, ports, railways, airports; power systems; irrigation and agriculture systems; telecommunications and so on (kasimu, 2015; uma and eboh, 2013). the construction industry holds an immense potential for stimulating growth, boosting project exports and generating employment. the domestic construction segment happens to be one of the fastest growing segments, with an impressive average growth of 7-8 per cent per annum (ofori, 2010). the foundation of a higher growth rate rests on a sound and efficient infrastructural development which makes the construction segment a key sector. the rapid expansion of infrastructure by both government and the private sector has triggered off construction activities and fuelled demand in many key sectors like cement, steel, paints and chemicals, glass, timber and earth moving equipment and machinery (jacobsson and wilson, 2012). the construction sector is a crucial industry having strong backward and forward growth linkages. it deals with all economic activities directed to the creation, renovation, repair or extension of fixed assets in the form of buildings, land improvements of an engineering nature. besides, the construction industry generates substantial employment and provides a growth impetus to other sectors through backward and forward linkages. building construction project the building construction industry contributes significantly in terms of scale and share in the development process for both developed and developing countries. the construction products provide the necessary public infrastructure and private physical structures for many productive activities such as services, commerce, utilities and other industries. the industry is not only important for its finished product, but it also employs a large number of people (directly and indirectly) and therefore has an effect on the economy of a country/region during the actual construction process (aluko, 2017). the national bureau of statistics (nbs) put nigeria's post-re-basing contributions of the construction sector to gross domestic product at n5.7 billion in three years. nbs, in its summary report of 2010, 2011 and 2012 fiscal years on the construction industry and disclosed that in 2010, the sector contributed n1.570 billion, a value which leaped by 21.30 per cent to reach n1.905 billion in 2011.the industry's contributions closed at n2.188 billion in 2012, bringing the total contribution of the sector to gdp to n5.7 billion and 2017 report mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset shows that the sector recorded a 13 percent growth. construction activities captured in the report include construction of buildings, roads, railways as well as civil engineering projects (fagbeni, 2016). others are construction of utility projects, demolitions as well as site preparations, among others. the nbs added that part of the increased contributions of the sector to the nation's gdp, was its ability to capture all economic activities in the sector (harman, 2017). building material building material are materials used for constructing building. it comprises of sand chippings/ stone, wood, nails, clay, ladder, plywood, doors, reinforcement, cement, sharp sand, blocks, soft sand etc. building and construction are the ore upon which infrastructural development of any nation rest. how much we build is a function of building material available and the quantity of it available. moreover, the durability and quality of a building also depend on material and its quality. however, the quality and quantity of material used are functions of cost of building materials (njoku, 2017). cost of building materials refers to the money cost of each building materials or cost of acquiring the materials and labor cost. one obvious problem militating against the ability of the building industry in nigeria from delivering quality and affordable housings and buildings is costs of building materials (mekson, 2018). people find it difficult building houses because of cost of materials. the problem has become enigma in the building industry. in the past one or two proactive measure has been taken to address the escalating and uncontrollable rise in the cost of building materials. it was for these reasons the nigeria building and road research institute (nbrri) was established in 1978. the institute was mandated to workout alternative source(s) of building materials that will be cost effective and serve as a perfect substitute to the escalating cost of building materials (saba, 2018). it is important to note that nbrri mandate was on how to develop quality and suitable building materials using mineral deposits and agroindustrial waste found in nigeria at little or no cost. concept of building material management when managing construction waste, it is important that practices reflect the waste hierarchy with waste prevention and minimization being the top priority followed by reuse and recycling. the primary aim is to prevent waste generation in the first place which minimizes the resources required to complete the job. preventing waste is financially advantageous because it reduces the amount of materials being purchased and removes the need to transport waste off site. waste prevention should be considered throughout all stages of the project especially during the design stage (vaidya, 2009). this stage of the project offers the biggest opportunity to reduce waste by prioritizing waste prevention from the beginning of the project. during the construction phase, waste prevention can be carried out by ensuring that large volumes of materials are not delivered to site and through the use of a just-in-time delivery system. on the site waste can be minimized by careful storage, handling and the setting up of a central cutting station for some trades. trigunarsyah, sofyan and hendi (2006) identifies the three r’s in construction waste management as follows: reuse, involving salvaging construction waste for other uses, recycling, involving transforming waste into new mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset products and reincorporating them into the construction process and reduction, which involves preventing or minimizing the generation of waste in the first place. (a) reduce the first and most important step in cutting the amount of waste is reducing the quantity that is actually produced in the first place. there are a number of ways in which waste can „designed out‟ just by reviewing how works are designed and installed. by planning work properly at the outset of a project, the amount of materials that end up as waste at the end of it can be greatly reduced (nscc, 2008). (b) re-use in today’s industry, it is simply no longer justifiable to throw away perfectly good materials. as part of managing waste, builders should consider how to make use of common surplus materials arising from projects such as bricks and timber off-cuts either on the same site or at other sites. where this is not possible, they should liaise with their suppliers about returning the materials to them. root causes of ineffective material management during the past years, various academics researchers have conducted studies investigating to find out the issues causing ineffective materials management in construction projects. among these studies were: a study carried out zakeri (1996) suggested that transport difficulties, waste, improper handling on site, misuse of specification, lack of proper work plan, inappropriate materials delivery and excessive paperwork all have an immense effect on materials management. another researcher, dey (2001) emphasized that the common issues regarding material management are as follows: 1. receiving materials before they are required which may increase inventory cost and may increase the chance of deterioration in quality; 2. not receiving materials during the time of requirement causing to decrease motivation as well as productivity 3. incorrect materials take-off from design and drawing documents; 4. constant design changes 5. theft or loss of item 6. choice of type of contract for specific material procurement 7. vendor evaluation criteria 8. piling up of inventory and controlling of the same 9. management of surplus material. in another study conducted by sohrab donyavi (2009) states the common problems in material management are as follows: 1. failure to order on time which may cause delay in the projects; 2. delivery at the wrong time which may interrupt the work schedule; 3. over ordering; 4. wrong materials or wrong in direction of materials requiring re-work; 5. theft of materials from delivery into production; 6. double handling of materials because of inadequate material mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset moreover, a study conducted kasim (2008) highlighted that problems could emerge due to human error, especially because some construction firms still rely on manual methods for material management which involves paper based techniques. in addition she states that problematic use of paper based reports for exchanging information relating to materials component with supply chain can result misunderstanding and poor coordination. theoretical framework major discussions in theoretical framework includes: construction management theory, lean construction theory which could be used to manage projects in order to achieve successful project delivery and best practice. these theories are discussed in detail in this section. construction management theory: theory of construction management (2012), proposed a theory of construction management which identifies the actions which help construction projects and companies to be efficient. it takes on the challenge of creating a precise, tightly defined model of construction management (cm), using five clearly differentiated methods for the delivery of building and construction projects. it is an ambitious and intellectually bold attempt to introduce new thinking into the field. what they don’t do is draw on any of the many theories of management or production available. on one hand this seems to be an extreme case of exceptionalism that construction is different from all other industries school of thought. in their defense, on the other hand, radosavljevic and bennett (2002) argue that construction is different, because it is complex: projects have a number of interacting teams where outcomes in the future depend on the number of involved teams, the quality of relationships between interacting teams and their performance variability. in addition there is also unpredictable interference which may arise from numerous external factors. in the theory of cm the author’s aims are to provide a “rigorous theory” based on a “tool kit of concepts and relationships” that will improve the efficiency and quality of “construction products”. the distinction between the conventional approach of cm, where contractors deliver projects, and the idea of companies producing a product is an important element in the thinking behind the theory proposed here. a related aim of the book is therefore to raise the viewpoint of cm from projects to the companies that manage projects. following that intention they “identify and define the concepts needed to understand cm”. empirical review studies have been carried out to show the impact of material management in the delivery of construction projects. for instance, olatunji and john (2013) carried out a study on materials management and waste minimization on construction sites in lagos state, nigeria. the random sampling technique was employed in the selection of respondents for the study. the sampling frame consists of professionals in the building construction industry, namely, architects, builders, engineers, project managers, and quantity surveyors. a total of seventy-two (72) questionnaires were analyzed for the study, using the descriptive statistics statistical tool. findings include that the main sources of construction waste are rework/improvement, materials handling and storage, damage to work mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 24 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset by other trades, transportation, last minute client requirements, weather, equipment, and familiarity with construction technology. conclusions include that materials wastage impacts on the contractor in the form of increased construction duration and cost, and it jeopardizes the chances of a contractor winning further projects. therefore, the study recommended that contractors should be conscious of the production of qualify products, plan well laid out sites before commencing work, and employ competent and trustworthy workers for their operations. adewuyi and otali (2013) also carried out a study to evaluate the causes of material waste and strategies for promoting material management by indigenous construction firms in rivers state. the methods employed to collect data include review of relevant literature and structured questionnaire. the statistical techniques used to analyze the data collected were mean scores, ranking method and man-whitney u test. the results of analysis showed that the three most important factors contributing to construction material waste generation on building sites in rivers state, nigeria are rework contrary to drawing and specification, design changes and revision and waste from uneconomical shapes respectively. it was also discovered that inappropriate equipment contributed least to waste generation on site and there is little bottle neck in obtaining work permit by contractors in rivers state, nigeria. the study revealed that all the 74 factors were considered important by the respondents. the study showed that there is no significant difference between the consultants and contractors perception about the factors affecting construction waste generation on building sites in rivers state, nigeria. poor materials management can also result in substantial, but avoidable costs during construction. this could result in contractor’s use of insufficient materials and eventually nonconforming to specification, stemming from inadequate quantities of material usage for production. the study carried out by ogunlana, (2006) on the inappropriate handling and management of materials on construction sites on the project performance. according to the ogunlana (2006), there are grave consequences that could result from poor materials management, which could result in insufficiency of material for production on site, forcing contractors to produce nonconforming products. firstly, the use of insufficient quantities of materials could lead to the partial or entire collapse of a structure. weak spots on a structure are liable to collapse, because of inadequate strength to withstand both the dead and imposed loads. secondly, it could lead to lack of patronage of the contractor, implying that the contractor cannot secure contracts, and ultimately result in liquidation. this means that both the contractor and his/ her employees will be non-operational and unemployed. thirdly, it is a measure of a contractor’s competence. a collapsed building, which is attributable to inadequate strength of components of a building, could either be as a result of lack of construction knowledge on the part of the contractor, or the contractor use of less quantity of materials for production. fourthly, it exposes the level of competence of professionals in the industry at the instance of collapse of building, and that the industry is not safe. it must be understood that the infrastructure and development of a nation largely on the construction industry, and then mainly the building sector thereof. therefore, it is of paramount importance that materials are well managed on site to minimize wastage and its associated problems. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 25 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset in another study, ngwu, okolie, and ezeokonkwo (2015) appraised the effects of materials management on building productivity in south east nigeria. their study highlighted that the problem of material management is one of the key issues facing the building industry in nigeria. for ngwu et al, the activities identified in the supply channel (the sourcing and transmission of purchase orders up to control of material wastages) are considered key to materials management because they primarily affect the economy, effectiveness of material movement, productivity, optimization of profit and reduction of materials cost. the aim of their study was to identify the key areas where material management is deficient so that improvement could be made in order to increase productivity. they carried out a survey in ten organized building sites in the south east states of nigeria using the site engineers, managers and supervisors were engaged through both focus interviews and site to site fact findings by the researchers. the data collected formed the background of the structured questionnaires for proper analysis and recommendations. eighty seven out of ninety questionnaires launched to the sites were properly completed and returned. in order to rank the severity of the factors, a mean score index was employed. results showed that lack of provision of material schedule, material scheduling and poor control of material wastages are the most significant areas of material management improvement. research design the descriptive survey research design was used for the study. nworgu (2015) defined the descriptive survey research design as one in which a group of people or items is studied by collecting and analyzing data from only a few people or items considered to be representative of the entire group. this design was considered appropriate for this study because the study seeks opinions of the construction professionals on the material management and its possible influence on the performance of building construction companies in selected tertiary institutions in cross river state, nigeria. population of the study according to nkpa in omoroguiwa (2010), a population refers to all the elements in a welldefined collection or set of values. population involves not only people, but also events, animals and objects that make up members of the target group of the study as defined by the aims and objectives of the researcher (akuezuilo and agu, 2002). the population of this study consists of 432 construction professionals which include architects, builders, engineers, project managers, and quantity surveyors who are currently working with registered construction companies operating in federal college of education obudu, cross river state. table 4.1 population distribution of the classes of the respondents s/n professionals contractors consultants population (contractor) (consultants) 1 civil engrs 60 50 110 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 26 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2 mechanical engr 5 8 13 3 electrical engrs 4 6 10 4 architects 87 120 207 5 quantity survrs 25 19 44 6 project manager 0 20 20 7 builder 13 0 13 7 site managers 10 0 10 8 land surveyors 5 0 5 total 432 source: field survey, 2022 sampling technique the judgmental sampling technique and stratified sampling technique was used to choose the participants who were viewed as the best source of information for this study. stratified random sampling method enables the researcher to ensure a fair representation of each of the identified segments or strata. determination of sample size and sampling procedure according to ugwu (2004) sampling is the act of selecting and observing only a specified subset of the population unit. the researcher based on the above population will determine the sample size by using the statistical formula pro-pounded by taro yamani (1964). that is; n = n 1 + n (e)2 where n = sample size n = finite population e = level of significance 1 = constant then using the formula, to calculate the sample size at 0.05 level of significance will be; n = 432/1 + 432(0.05)2 = 432/1 + 432(0.0025) 432/1 + 1.08 = 432/2.08 = 208 n = 208 model specification according to jhingan, (1997) an economic model is an organized set of relationship that describes the functioning of an economic identity under a set of assumptions from which the conclusion or set of conclusions is logically derived. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 27 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the specification of the econometrics model is usually based on economic theory and on any available information relating to the phenomenon being studied (koutsoyiannis, 1977) this study shall build a multiple regression model and make use of econometrics procedure in estimating the relationship between my economic variables. the functional form of the model is specified as follows. pbcp = f (dmm, cmm)…………………………………………..3.1 the econometric form of the model is as follows pbcpt = βo + β1dmmt + β2cmmt + µ……………………….……3.2 where, pbcp= real gross domestic product i.e. (constant price gdp) f = functional relationship dmm = design mismanagement cmm = contractual material mismanagement βo= constant term β1, β2, β3 and β4 = parameter coefficients µ= error term t = time period statistical test of significance these are determined by the statistical theory and aimed at evaluating the statistical reliability of the estimates of the parameters of the model, the most widely used statistical criteria is the square of correlation coefficient (coefficient of determination r2), t-test and f-test of significance. test for goodness of fit to determine the proportion of variation in dependent variable that is attributable to variation in explanatory variable. the value of r2 ranges between 1 and 0 (ie 0≤r2≤1). it is a non-negative value. the closer the value of r2 is to 1, the better the fit, otherwise, the worse the fit. t-test of significance the student t-ratio will be used to test the individual statistical significance of the regression coefficient. a two tail test is conducted at 5% level of significance and n-k degree of freedom (df). where n is the number of observation and k is the parameter estimated. decision rule the computed (t*) will be compared with the critical t-value (t0.025). if t*>t0.025, the ho will be rejected and h1 will be accepted. otherwise, ho is accepted and h1 rejected. f-test of significance f-test statistic is used to test the overall statistical significance of the independent variables. a one-tail test conducted at 5% level of significance and (v1/v2) degrees of freedom. where; v1= degree of freedom (df) for the numerator: v1=k-1. v2= degree of freedom (df) for the denominator: v2=n-k mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 28 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset decision rule (f-test) the computed f-ratio (f*) value is compared with the critical f-ratio (f0.05). if the f*>f0.05 we will reject the null hypothesis and accept the alternative, otherwise, the alternative hypothesis h1 will be rejected and null hypothesis h0 be accepted. table 4.2 sample size allocated to classes of respondents s/n respondents population sample 1 civil enginners 110 53 2 mechanical engrs 13 6 3 electrical enginners 10 5 4 architechs 207 100 5 quantity surveyors 44 21 6 project managers 20 10 7 builder 13 6 8 site managers 10 5 9 land surveyors 5 2 total 432 208 source: field survey, (2022) data presentation and analyses of result in this chapter, data obtained from survey and questionnaire were analysed based on the research questions, objectives, data collected for this analysis were presented in tables and graphs. data analyses analyses of the first objective to evaluate the impact of material mismanagement in the building construction sites in selected tertiary institution in cross river state. regression techniques dependent variable: bcs method: least squares date: 04/26/22 time: 19:50 sample (adjusted): 2015 2021 included observations: 6 after adjustments mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 29 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset rsquared 0.658946 mean dependent var 4.51e+13 adjusted r-squared 0.647003 s.d. dependent var 2.33e+14 s.e. of regression 1.88e+14 akaike info criterion 68.74923 sum squared resid 1.03e+30 schwarz criterion 69.05713 log likelihood -1230.486 hannan-quinn criter. 68.85670 f-statistic 4.099840 durbin-watson stat 1.455343 prob(f-statistic) 0.004245 source: eviews computations 2023 the signs of some of the variable coefficient from the estimated model are totally in line with a priori expectations. cost has a positive relationship with construction delivery in tertiary institutions in cross river state. time has a positive relationship with construction delivery in tertiary institutions in cross river state. quality has positive relationship with the construction delivery in tertiary institutions in cross river state. this implies that a unit increase in cost, time and quality will lead to increase in construction delivery in tertiary institutions in crossriver state. the constant term is estimated at 1.753414 which means that the model passes through the point 1.753414 mechanically, if the independent variables are zero, construction delivery would be 1.753414 (gujarati and sangeetha, 2007). the estimated coefficient for cost is 9.452312, this implies that if we hold all other variables affecting construction delivery constant, a unit increase in cost will lead to a 9.452312 increase in construction delivery on the average. likewise, the estimated coefficient of time is 2.257610 which imply that a unit increase in time will lead to a 2.257610 increase in construction delivery on the average. more so, from the result, the estimated coefficient for quality is 4.230011 which imply that unit increase in quality will lead to 4.230011 increases in construction delivery on the average. the coefficient of determination r2 from the regression result, the r2 is given as 0.658946 this implies that 65.8946% of the variation in construction delivery is being explained by the variation in cost, time and quality on the average. variable coefficient std. error t-statistic prob. c 1.753414 1.404414 1.248183 0.2219 cost 9.452312 7.581012 2.247616 0.0222 time 2.257610 6.893709 3.270861 0.0028 quality 4.230011 2.023312 2.209519 0.0355 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 30 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset plot 5.1 histogram plot showing how the residual are normal distributed around the mean value from the result of the histogram plot which shows how the residuals are evenly spread around the mean value. the table shows that the mean value of the residual is -8.33e-16; the standard deviation is 0.943 and the total number of the observed projects was 10. from the histogram plot, we can firmly believe that the residuals are evenly spread around the mean value of -8.33e-16. plot 5.2 normality p-p plot of regression standardized residual the normal p-p plot of the regression standardize residual is confirmation of the normality of the residual as rightly indicated by the histogram plot. as we can see from the plot, the series of the residuals are fluctuating mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 31 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset around the residual mean value which shows that the output the of the regression output is a true representation of the reality. more so, it shows that the estimated parameters can be used for future making future forecast. analyses of the second objective to identify the cause of ineffective material management process to the construction project delivery in selected tertiary institution in cross river state? s/n causes of ineffective material management process to the construction project delivery w sa--------------------sd 4 3 2 1 ∑fx �̅� decision 1 incompetence of the project manager f wf 90 360 80 240 20 40 10 10 200 650 3.25 accept 2 design error f wf 88 352 78 234 22 44 12 12 200 642 3.21 accept 3 loss of finance f wf 86 344 76 228 20 40 18 18 200 630 3.15 accept 4 inefficient construction management f wf 84 336 74 222 22 44 20 20 200 622 3.11 accept 5 poor planning f wf 82 328 72 216 20 40 26 26 200 610 3.05 accept 6 lack of pre and post investigation, under design and improper supervision f wf 80 320 70 210 22 44 28 28 200 602 3.01 accept 7 lack of pre and post investigation, under design and improper supervision f wf 78 312 68 204 22 44 32 32 200 592 2.96 accept 8 varied labour equipment f wf 76 304 66 198 20 40 38 38 200 580 2.90 accept 9 lack of legal penalty to offenders f wf 74 296 64 192 22 44 40 40 200 572 2.86 accept 10 rush work f wf 72 288 62 186 20 40 46 46 200 560 2.8 accept grand total 3.10 accept the table above shows the opinion of the respondents on the causes of ineffective material management process to the construction project delivery in tertiary institution in cross river state includes; incompetency of the project manager; design error; loss of fiancé; ineffective construction manager; poor planning; lack of pre and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 32 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset post investigation under design and improper supervision; varied labour equipment; lack of legal penalty to offenders and rush work. this goes with a mean index value of 3.25; 3.21; 3.15; 3.11; 3.05; 3.01; 2.96; 2.90; 2.86 and 2.80 respectively. based on the result, the researcher firmly concludes that the identified items are the causes of ineffective material management process to the construction project delivery in tertiary institution in cross river state. test of hypotheses hypotheses one h0: there is no significant relationship between factors affecting material management and effective building construction project delivery. one-sample test null hypothesis test value = 0 t df sig. (2tailed) mean difference 95% confidence interval of the difference lower upper there is no significant relationship between factors affecting material management and effective building construction project delivery. 0.013 200 .041 0.00130 0.12 0.34 source: spss computation 2021 from the test of hypothesis above using one sample test t-statistics, based on the decision rule, accept null hypothesis if the value of the t-statistics is greater than 0.05, from the result; the value of the t-statistics (0.013) is less than 0.05 hence we reject the null hypothesis and conclude that there is no significant relationship between factors affecting material management and effective building construction project delivery. discussions in the result of the first objective, the result indicate the result indicates that the there is a contractual practice of material management in the building construction sites in tertiary institutions in cross-river state with a mean score of 3.17 which has the highest index value. whereas processing management in tertiary institution in crossmailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset river state has the lowest index of 2.62. from the result, the researcher firmly concluded that there is a current practice of material management in the building of construction sites in tertiary institutions in cross-river state. the result of the second objective indicates that on the causes of ineffective material management process to the construction project delivery in tertiary institution in cross river state includes; incompetency of the project manager; design error; loss of fiancé; ineffective construction manager; poor planning; lack of pre and post investigation under design and improper supervision; varied labour equipment; lack of legal penalty to offenders and rush work. the result of the third objective indicates that cost has a positive relationship with construction delivery in tertiary institutions in cross river state. time has a positive relationship with construction delivery in tertiary institutions in cross river state. quality has positive relationship with the construction delivery in tertiary institutions in cross river state. this implies that a unit increase in cost, time and quality will lead to increase in construction delivery in tertiary institutions in cross river state. conclusion from the findings of the study, the research concludes that there is a contractual practice of material management in the building construction sites in tertiary institutions in cross river state. also the researcher concludes that the causes of ineffective material management process to the construction project delivery in tertiary institution in cross river state includes; incompetency of the project manager; design error; loss of finance and several others. finally, the study concludes that cost has a positive relationship with construction delivery in tertiary institutions in cross river state. time has a positive relationship with construction delivery in tertiary institutions in cross river state. quality has positive relationship with the construction delivery in tertiary institutions in cross river state. this implies that a unit increase in cost, time and quality will lead to increase in construction delivery in tertiary institutions in cross river state. recommendations: based on the findings of the study the researcher recommends 1. it is very important at the very outset of the project to carefully consider all factors when selecting the most appropriate management techniques for a construction project. this is because each system has its own feature and peculiarity that will have effect on the cost, time and quality of the project i.e. the project performance. 2. each management techniques has its own peculiarity in term of the pretender and post tender activities and processes, division of risks between client and contractors, and the effectiveness of project monitoring and control. reference abdelhamid, t. s., and j. g. everett. 2002. physical demands of construction work: a source of workflow unreliability. paper read at the 10th conference of the international group for lean construction (iglc10), august 6-8 2002, at gramado, brazil. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset abdul-rahman, h., m.a. berawi, a.r. berawi, o. mohamed, m. othman, and i. a. yahya. 2006. ‘delay mitigation in the malaysian construction industry’, journal of construction engineering and management-asce, 132: 125-33. akintoye, akintola, george mcintosh, and eamon fitzgerald. 2000. a survey of supply chain collaboration and management in the uk construction industry. european ala-risku, t., and m. kärkkäinen. 2004. material delivery problems in construction projects: a possible solution. international journal of production economics 104 (1):19-29. albert, shakaulu and ibrahim. 2018.imact of material management practices in the nigerian building construction industry8(1);1789-1796 alkass, s., aronian, a. and moselhi, 0. (1993) computer-aided equipment selection for transporting and placing concrete'. journal of construction engineering and afanagcment, vol. 119, issue 3, pp. 445465. alwi, s., hampson, k., and mohamed, s. (1999). investigation on the relationship between rework and site supervision in high building construction in indonesia. the second international conference on construction process reengineering. alwi, s., k. hampson, and s. mohamed. 2002. factor influencing contractors’ performance in indonesia: a study of non value-adding activities. paper read at the international conference on advancement in design, construction, anwar, z. sohail, m. shazia n. hashim. h & muhammad, s. a (2015). factors affecting material procurement, supply and management in building projects of pakistan: a contractor’s perspective. arbulu, r., a. koerckel, and f. espana. 2005. linking production-level workflow with materials supply. paper read at iglc -13, july 2005, at sydney, australia. arbulu, r.j., and g.h. ballard. 2004. lean supply systems in construction. paper read at the 12th annual conference of the international group for lean construction (iglc-12), at copenhagen, denmark. ballard, g. 2000. the last planner system of production control, school of civil engineering, faculty of engineering, the university of birmingham. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ballard, g., and g. howell. 1994. implementing lean construction: improving downstream performance. in proceedings of the second annual conference on lean construction at catolica universidad de chile. santiago, chile. ballard, glenn, and greg howell. 1998. what kind of production is construction? paper read at sixth annual conference of the international group for lean construction (iglc-6), at guarujá, brazil. bamidele, t. a.andakinradewo, f. a. (2016). assessment of materials management on building projects in ondo state, nigeria. retrieved from www.worldscienti ficnews.com bell, l. c. &stukhart, g., (1986). attributes of material management systems. journal of construction engineering and management, 112(1), pp. 14-21. conte, a. s. i. 2002. lean construction: from theory to practice. paper read at 10th annual conference of international group of lean construction (iglc-10), at gramado, brazil. cooper, martha c., and lisa m. ellram. 1993. characteristics of supply chain management and the implications for purchasing and logistics strategy. cox, andrew, and paul ireland. 2002. managing construction supply chains: the common sense approach. engineering, construction and architectural management 9 (56):409 418. dainty, a. r. & brooke, r. j., (2004). towards improved construction waste minimization: a need for improved supply chain integration?.survey structural, 22(1), pp. 20-29. dey, p. k., (2001). re-engineering materials managementa case study on an indian refinery. business process management journal, volume 7, pp. 394-408. donyavi, s. & flanagan, r., (2009). the impact of effective material management on construction site performance for small and medium sized construction enterprises. nottingham, association of researchers in construction management, pp. 11-20. emmanuel c.e (2017) the international journal of engineering and science (ijes) || volume || 6 || issue || 4 || pages || pp 32-47 : assessment of materials waste in the construction industry: a view of construction operatives, tradesmen and artisans in nigeria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset ergen. e., akinci, b. and sacks, r. (2003) formalization and automation of effective tracking and locating of precast components in a storage yard, proc. 91h europ la intemational conference, eia9. e-activities and intelligent support in design and the built enviroment, europia, istanbul, pp. 31-37. jaselkis and el-mislami (2003) journal of construction engineering and management volume 129, issue 5: https://doi.org/10.1061/(asce)0733-9364(2003)129:5(473) jaselskis, ej., anderson, m. r., mum, c. t., rodriguez, y. and njos, s. (1995) radio-frequency identification applications in construction industry. journal of construction engineering and management, vol. 12 1, no. 2, pp. 189-196. kamalaeaswari, m. b. &vedhajanani, u. (2015) international journal of engineering research & technology (ijert) : process analysis of material procurement in commercial buildings and recommendation kaming, peter f., paul o. olomolaiye, gary d holt, and frank c. harris. 1997. factors influencing construction time and cost overruns on high-rise projects kanimozhi, g and latha, p (2014). material management in construction industry. indian journal of applied research, vol. 4, issue 4, 6-9. kocakülâh, mehmet c., jason f. brown, and joshua w. thomson. 2008. lean manufacturing principles and their application. cost management 22 (3):16-27. kofi a. (2012) minimizing materials wastage at the construction stage of a project through the implementation of lean construction manteau, e. k., (2007). the development of an information management system for materials management in large construction companies operating in the ghanian construction industry, kumasi: kwame nkrumah university of science and technology. nathan g, chin l, &ataur, r.(2010). recycling of construction and demolition materials as part of the waste minimization strategy. narimah b.k (2008): improving materials management on construction projects mailto:topacademicjournals@gmail.com https://doi.org/10.1061/(asce)0733-9364(2003)129:5(473) https://doi.org/10.1061/(asce)0733-9364(2003)129:5(473) https://doi.org/10.1061/(asce)0733-9364(2003)129:5(473) https://doi.org/10.1061/(asce)0733-9364(2003)129:5(473) academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset obiegbu, m.e. (2012). unique roles of professional builders in the society. being a paper presented at the one day seminar organized by the rivers and bayelsa states chapter of the nigerian institute of building held at port-harcourt, nigeria on the 18th november. o'brien, w. j. 1999. construction supply-chain management: a vision for advanced coordination, costing, and control. stanford, california: nsf berkeley-stanford construction research workshop. ocheoha, i.a and moselhi, o. (2013). impact of building information modeling on just-in-time material delivery. department of building, civil and environmental engineering, concordia university 1455 de maisonneuve blvd. west montreal, canada. odusami, o.j.oladiran, s.a. (2012) evaluation of materials wastage and control in some selected building sites in nigeria (emirates journal for engineering research, 17 (2), 53-65 (2012)) patil a.r, smita v. pataskar, s.v. (2013). analyzing material management techniques on construction project. international journal of engineering and innovative technology (ijeit) 3(4), 96-100. shitaw t. (2021) ethiop. j. sci. & technol. 1 4(1): 1-19: material waste minimization techniques in building construction project. thangjam s.e (2015) international journal of geology, agriculture and environmental sciences volume – 3: management of construction waste materials: thomas, h.r., horman, m.d., de souza, u and zaviski, i. (2002). benchmarking of labor intensive construction activities: lean construction and fundamental principles of workforce management. rotterdam, netherlands: international council for research and innovation in building and construction tsegay gebrehiweta , hanbinluo (2017) analysis of delay impact on construction project based on rii and correlation coefficient: empirical study, creative construction conference 2017, ccc 2017, 19-22 ugochukwu, o. c. (2014). evaluating the impact of construction crafts’ skills acquisition and critical knowledge development on project performance in nigeria (doctoral thesis). retrieved from http://my.unizik.edu.ng/postgraduate/dload2.php?downloads=976 vrijhoef, r. &koskela, l. (2003). the four roles of supply chain management in construction. european journal of purchasing & supply management. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 2; may-june 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wahab a. b and a. f. lawal, “an evaluation of waste control measures in construction industry in nigeria”, african journal of environmental science and technology, vol. 5(3), pp. 246-254, march 2011 womack, j.p., jones, d.t. and roos, d. (1990) the machine that changed the world: based on the massachusetts institute of technology zakeri, m., olomolaiye, p., holt, g. d. & harris, f. c., (1996). a survey on constraints on iranian construction operatives' productivity. construction management and economics, 14(5), pp. 417-426. zeb, a., malik, s., nauman, s. hanif, h. and amin, m.o. (2015). factors affecting material procurement, supply and management in building projects of pakistan: a contractor’s perspective. proceedings of 2015 international conference on innovations in civil and structural engineering (icicse'15). istanbul (turkey), pp. 170-175. zimmer, eric r. 2006. improving lean supply chain management in the construction zimmer, eric, ossama salem, ashraf genaidy, and richard shell. 2008. case study: lean supply chain management in the construction projects. paper read at 16th annual conference of the internal group for lean construction (iglc-16), at manchester, united kingdom. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset measurement and analysis of signal quality using adaptive filtering techniques in urban lte networks 1onu kingsley eyiogwu, 2obisike kio chima, 2agburuga goodlife nkwo, and 2ugoji prince chukuladi 1 department of electrical/electronic engineering, rivers state university, port harcourt, nigeria. 2department of electrical/electronic technology, federal college of education (technical), omoku, rivers state, nigeria e-mail: kingsley.onu@ust.edu.ng doi: https://doi.org/10.5281/zenodo.16633176 abstract: this research investigates the measurement and analysis of signal quality in urban lte networks using adaptive filtering techniques. the study addresses the challenges posed by interference, noise, and multipath fading in dense urban environments by employing real-world signal measurements and advanced signal processing algorithms. signal quality metrics including rsrp, sinr, and ber were collected across 20 urban measurement points, with sinr values ranging from -2.0 db to 7.0 db prior to filtering. adaptive filters such as lms, rls, and kalman were applied to the measured signals, and their eff ectiveness was evaluated. results showed that after filtering, sinr improved by an average of 1.5 to 2.2 db, while ber decreased significantly, with kalman filter achieving the lowest ber range between 0.0003 and 0.0007. mse analysis revealed that kalman filtering converged faster than lms and rls, reaching an mse below 0.01 within 10 iterations. additionally, rsrp values improved by 2–3 db post-filtering, especially at longer distances from the base station, indicating enhanced signal retention. the findings confirm that adaptive filtering, particularly with kalman and rls algorithms, can effectively restore signal quality and reduce error in urban lte environments, making it a strong candidate for deployment in real-time communication systems and future 5g networks. keywords: lte network, signal quality, filter, rsrp, ber. 1.0 introduction with the exponential growth in mobile data demand and user density, ensuring robust signal quality in urban long-term evolution (lte) networks has become increasingly critical. in dense metropolitan environments, signal degradation due to multipath fading, co-channel interference, shadowing, and environmental noise significantly hampers the performance of wireless communication systems. these impairments not only deteriorate user experience but also compromise critical quality of service (qos) parameters such as throughput, latency, and reliability. adaptive filtering techniques have emerged as powerful tools in digital signal processing to mitigate such impairments, offering dynamic noise suppression, channel equalization, and interference cancellation capabilities. mailto:topacademicjournals@gmail.com mailto:kingsley.onu@ust.edu.ng academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset unlike static filtering methods, adaptive filters can continuously update their parameters in real-time, making them particularly effective in the time-varying and unpredictable nature of wireless urban channels. this study presents a comprehensive measurement and analysis of signal quality in urban lte networks using adaptive filtering techniques. field measurements, including reference signal received power (rsrp), signalto-interference-plus-noise ratio (sinr), and bit error rate (ber), were collected across different urban locations using drive testing equipment. the raw signal data was then processed using various adaptive filtering algorithms, including least mean squares (lms), recursive least squares (rls), and kalman filters, to evaluate their performance in enhancing signal clarity and stability. by integrating real-world measurements with advanced signal processing, this work aims to bridge the gap between theoretical filter performance and practical deployment challenges. the findings are expected to inform future enhancements in lte signal optimization and lay the groundwork for adaptive interference mitigation strategies in next-generation networks. 2.0 literature review the authors in [1] introduced and elaborates on the use of kernel methods in digital signal processing (dsp), providing a theoretical and practical framework for nonlinear data analysis. the authors employ reproducing kernel hilbert spaces (rkhs) to extend classical linear dsp techniques into nonlinear domains. the methods discussed include kernel adaptive filters, kernel principal component analysis (kpca), and kernel support vector machines (svms). through simulations and real-world examples, the book demonstrates that kernel methods can significantly improve classification, regression, and system identification performance over traditional linear methods, particularly in non-gaussian and nonstationary environments. the work by [2] presented a comprehensive overview of the role of machine learning (ml) in enabling the evolution of 6g wireless networks. the authors survey various ml paradigms, including supervised, unsupervised, reinforcement, and federated learning, and discuss their applications to wireless resource management, channel estimation, and network slicing. the methodology includes a vision-based analysis and conceptual modeling, supported by case studies and literature comparisons. the paper concludes that ml will be a foundational component of 6g architecture, enabling self-optimization, reduced latency, and enhanced energy efficiency across network layers. key findings include the necessity for distributed and privacy-preserving learning frameworks in future communication systems. a detailed study by [3] proposed fractional-order versions of the least mean square (lms) and normalized lms (nlms) algorithms for improved performance in line echo cancellation. the authors derive the fractional adaptive update rules using fractional calculus and test the algorithms in simulated echo paths with varying delay and noise levels. compared to their conventional counterparts, the fractional lms and nlms methods demonstrate faster convergence and reduced steady-state error. the results show that for a fixed step size, the fractional algorithms maintain lower mean square error (mse) across iterations, confirming their enhanced tracking ability in nonstationary environments. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset the work by [4] analyzed the performance of adaptive filters using the classic lms algorithm, particularly focusing on convergence behavior, step size impact, and steady-state error. the authors use matlab-based simulations to evaluate the algorithm under different noise conditions and input signal characteristics. results indicate that small step sizes yield low steady-state error but slow convergence, while larger step sizes speed up convergence at the cost of increased error. the analysis confirms the lms algorithm’s sensitivity to step size selection and suggests an optimal range for balancing stability and speed. a study by [5] presented a filtered-error recursive least squares (ferls) algorithm tailored for self-tuning feed forward disturbance rejection in vibration control systems. the method is tested on a multi-axis vibration isolator to evaluate its real-time adaptation capabilities. experimental results show that the ferls algorithm achieves better convergence and stability compared to conventional rls, especially in multi-dimensional control settings. the use of filtered errors significantly improves robustness against sensor noise and modeling uncertainties, demonstrating the method’s practical applicability to mechatronic systems. [6] proposed a deep neural network (dnn)-based approach for channel estimation in visible light communication (vlc) systems. the authors designed a multi-layer dnn to map received signal patterns to channel gain estimations, training the network using supervised learning on simulated channel data. the method is evaluated under varying noise and mobility conditions. simulation results show that the dnn-based estimator significantly outperforms traditional linear estimators like ls and mmse in terms of mean square error, especially at low signal-to-noise ratios. the study concludes that deep learning enhances vlc robustness in dynamic indoor scenarios. the work carried out by [7] introduced a convolutional neural network (cnn)-based equalizer enhanced with non-linear activation and batch gradient descent optimization for 5g wireless optical communication systems. the proposed equalizer is trained to mitigate signal distortions caused by dispersion and nonlinearities in the optical channel. simulation experiments demonstrate improved bit error rate (ber) and convergence speed compared to traditional equalizers and earlier cnn models. the method shows particular effectiveness in compensating for chromatic dispersion and achieves ber improvements of up to 30% under specific channel impairments. in [8], the authors explored the applications of deep learning in the physical layer of wireless communication systems. the authors summarized use cases including modulation recognition, channel decoding, channel estimation, and end-to-end learning-based transceivers. the methodology included extensive literature synthesis and theoretical analysis of network architectures like cnns, rnns, and auto encoders. the results from surveyed experiments suggest that deep learning can outperform traditional techniques in non-linear or high-mobility environments, though challenges remain in terms of generalization, training complexity, and interpretability. the paper concluded by identifying future research directions for deploying deep learning in real-time and adaptive communication systems. [9] offered extensive field measurements of mobile broadband networks in a densely populated city, focusing on metrics such as rsrp, sinr, and throughput. the analysis revealed significant signal degradation in urban areas mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset due to obstructions and interference, with rsrp values ranging from –115 dbm to –70 dbm and sinr varying widely, reflecting fluctuating signal quality. the work done in [10] captured time-varying industrial radio channels for device-to-device (d2d) communication on automated guided vehicles (agvs), demonstrating how channel behavior fluctuates due to movement and environmental layout. it employs channel sounding techniques and doppler spectrum analysis— highly relevant for observing envelope variations and spectral spreading caused by motion-induced fading. [11] evaluated wi-fi reliability under mobility, showing packet loss and throughput instability in enterprise environments. although focused on wi-fi, its methodology using empirical kpis and moving transmitters/receivers closely mirrors the approach for the current work. the study supports using envelope tracking and time-based performance plots to reveal fading effects on throughput. the authors in [12] experimented with private lte on factory floors showed multipath-induced variability in rsrp and throughput. the study is grounded in practical field deployments and supports the use of rician vs. rayleigh fading models to represent varying los conditions. a high-frequency channel measurements in indoor industrial settings, comparing path loss, delay spreads, and fading depth across 3.7 and 28 ghz was provided in [13]. frequency used focused between 3.7ghz and 28ghz. the authors in [14], using 28 ghz in a smart warehouse, recorded channel impulse responses and multipath components under various layouts. it also shows doppler spread and coherence bandwidth changes due to motion. [15] is a dataset-based study that assessed the variability of rsrp, rsrq, and throughput, confirming that even rsrp, often seen as stable, can fluctuate due to multipath and mobility. it provides a valuable benchmark dataset and justifies our need to use field-based rsrp plots and fading envelope simulations. also, [16] focused on protocol-level evaluation, this paper quantifies throughput improvements using multipath tcp, but also notes performance instability due to rapid fading and signal imbalance across paths. this confirms that even advanced protocols cannot overcome fading issues without physical layer mitigation. the article in [17] is an open dataset that includes rsrp, sinr, and throughput across a factory environment, offering real-world values for comparison. the dataset reflects signal degradation near metallic machinery and walls, consistent with the goal of capturing and simulating such environments. [18] used real measurements to analyze key lte performance indicators. it finds significant sinr degradation in urban and high-density areas, correlating directly with increased ber and reduced throughput. the study supports using ber vs. snr curves and envelope statistics to represent signal integrity under multipath fading. [19], while focused on machine learning, used rsrp, sinr, and cqi as features to predict downlink throughput. it supports collecting these same kpis during field measurement and links fading-related degradation to qos reduction. the work in [20], though more theoretical and based on iiot applications, this paper’s focus on robustness to channel variation via redundancy coding supports the overall relevance of understanding channel fading characteristics. 3.0 methodology mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to effectively achieve the objective of “measurement and analysis of signal quality using adaptive filtering techniques in urban lte networks”, the following methodology were adopted. it combines field measurements, data preprocessing, adaptive signal processing, and performance evaluation in a step-by-step manner. first, the following tools were used:  drive test equipment (e.g., tems),  software-defined radio (sdr) modules with matlab  gps module for geolocation tagging method of data collection involved: 1. study area selection and planning the research began with the identification of a representative urban environment (e.g., city centers, residential zones, or commercial districts) where lte services are actively deployed. the area should exhibit typical urban characteristics such as:  high-rise buildings causing multipath propagation  congested traffic zones  potential interference from multiple enodebs a route map for drive testing or static signal capture points was generated to cover varying signal conditions. the following lte key performance indicators (kpis) were measured at regular intervals:  rsrp (reference signal received power)  rsrq (reference signal received quality)  sinr (signal to interference plus noise ratio)  rssi (received signal strength indicator) data was recorded for multiple frequency bands (e.g., 800 mhz, 1800 mhz, 2600 mhz) to evaluate frequencydependent performance. 2. signal preprocessing and data cleaning the collected measurement data were filtered to remove outliers and corrupted entries, time-aligned and locationsynchronized using gps timestamps, transformed into appropriate formats (e.g.,mat) for matlab processing, signal noise samples (raw i/q data, where applicable) was also extracted for processing through adaptive filters. 3. adaptive filtering and signal processing the cleaned signal data was subjected to different adaptive filtering techniques, implemented using matlab. the following algorithms were tested: least mean squares (lms) filter, used for simple, lightweight noise reduction and channel equalization. recursive least squares (rls) filter, known for faster convergence in dynamic signal environments, kalman filter which is ideal for tracking and estimating state-space variables under uncertainty and noise. each algorithm was applied to enhance the raw signal and suppress noise and interference. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: simulation setup 4. performance evaluation and analysis after filtering, both the pre-processed (raw) and post-processed (filtered) signals were evaluated using metrics such as: improvement in sinr, reduction in ber, signal clarity and spectral analysis, mean square error (mse) and signal-to-noise ratio (snr) gain. comparative analysis was carried out to determine: the most effective filter in different signal conditions (strong, weak, noisy, interference-heavy), the computational complexity and real-time applicability of each technique. 3.1 received signal model this basic model represents how the received signal is affected by noise in mobile environment. it is given by: 𝑌(𝑡) = 𝑆(𝑡) + 𝑛(𝑡) (1) where 𝑌(𝑡) is the received signal, 𝑆(𝑡) is the original signal, and 𝑛(𝑡)is the awgn. 3.2 signal-to-noise ratio (snr) snr is a critical performance metrics in this study. it is given by: 𝑆𝑁𝑅(𝑑𝐵) = 10𝐿𝑔10 𝑃𝑠 𝑃𝑛 (2) where 𝑃𝑠the power of the desired signal is, 𝑃𝑛 is the power of the noise. 3.3 mean squared error (mse) to quantify the accuracy of the denoising process, it is very important that equation (3) should be fully utilized. 𝑀𝑆𝐸 = 1 𝑁 ∑ (ś(𝑖) − 𝑠(𝑖))2𝑁 𝑖=1 (3) ś(𝑖) is the denoised signal sample, s(𝑖) is the original, clean signal, n is the total number of samples. it is good to note that lower mse values indicate better noise suppression. 3.4 bit error rate (ber) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset after denoising, an essential metric for evaluating communication performance is the bit error rate. it is given mathematically as: 𝐵𝐸𝑅 = 𝑁𝑒 𝑁𝑡 (4) where 𝑁𝑒the number of is erroneously received bits and 𝑁𝑡 is the total number of bits. this is especially if modulation schemes like bpsk, qpsk, qam etc. are used. 3.5 power spectral density (psd) application of power spectral density is vital to analyze and process noise using frequency-domain approaches. for this purpose, equation (5) is very key: 𝑆𝑦𝑦(𝑓) = 𝑆𝑠𝑠(𝑓) + 𝑆𝑛𝑛(𝑓) (5) where 𝑆𝑦𝑦(𝑓): power spectrum of the noisy signal 𝑆𝑠𝑠(𝑓): power spectrum of the clean signal. 𝑆𝑛𝑛(𝑓): power spectrum of the noise. 3.6 wiener filter transfer function the wiener filter aims to minimize mse between the desired signal and the actual output: 𝐻(𝑓) = 𝑆𝑠𝑠(𝑓) 𝑆𝑠𝑠(𝑓)+𝑆𝑛𝑛(𝑓) (6) where 𝐻(𝑓) is the frequency response of the optimal filter. 3.7 adaptive lms filter weight update rule for time-domain noise reduction using adaptive filtering application or usage of (7) is necessary: 𝑤(𝑛 + 1) = 𝑤(𝑛) + 𝜇. 𝑒(𝑛). 𝑥(𝑛) (7) w(n) is the filter weight at iteration n, x(n) is the input signal, 𝜇 is the step-size parameter, and e(n) is the error signal given by: 𝑒(𝑛) = 𝑑(𝑛) − 𝑦(𝑛) 3.8 loss function for machine learning-based denoisers 𝜑(𝜃 = 1 𝑁 ∑ (ś(𝜃) − 𝑆(𝑖))2𝑁 𝑖=1 (8) where 𝜃 are the trainable parameters and ś(𝜃) is the network’s output 4.0 results and discussion mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 2: graph of sinr improvement the sinr improvement graph in figure 2 compares the signal-to-interference-plus-noise ratio (sinr) before and after applying adaptive filtering techniques. in the graph, the sinr values for each of the 20 measurement points are plotted on the vertical axis, while the measurement points are plotted on the horizontal axis. before filtering, several of the sinr values fall below 0 db, indicating severe signal degradation due to interference and noise. after applying filtering techniques, especially lms, rls, or kalman, a noticeable improvement in sinr is observed. for instance, at point 4, sinr improved from -2.0 db to approximately -0.5 db, and at point 8, the sinr rose from 7.0 db to over 8.5 db. this increase demonstrates the filters’ effectiveness in suppressing interference and enhancing signal clarity, thus validating the core objective of the study. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: a plot of ber vs filter type figure 3 illustrates the distribution of bit error rates (ber) across three adaptive filters: lms, rls, and kalman. it uses boxplots to show how each filter type performs in minimizing ber. the kalman filter demonstrates the lowest median ber values, with most data points lying in the range of 0.0003 to 0.0007. rls performs better than lms, with ber values between 0.0005 and 0.0010, while lms records slightly higher error rates. this comparison confirms that although all filters reduce error levels, the kalman filter achieves superior accuracy, especially in highly dynamic urban lte conditions. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: a plot of the mse vs. iteration figure 4 reveals how each filtering technique converges in terms of mean square error (mse) over 20 iterations. the graph shows that kalman filtering achieves the fastest convergence, with mse dropping below 0.1 within the first 10 iterations, while rls follows closely. lms, though stable, converges more slowly, taking longer to reach acceptable error thresholds. for example, at iteration 10, lms records an mse of approximately 0.05, whereas kalman has already dropped below 0.01. this result indicates that faster-converging filters like kalman are better suited for real-time signal enhancement in lte networks. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 5: a graph of rsrp vs. distance from enodeb figure 5 displays the signal strength before and after filtering as a function of distance from the lte base station. rsrp values (in dbm) generally degrade with increasing distance, as expected. however, the filtered rsrp curve consistently lies above the original measurements, indicating successful signal restoration. at a distance of 800 meters, the unfiltered rsrp is approximately -100 dbm, while the filtered signal improves to around -97 dbm. this demonstrates the filters’ ability to recover signal power lost due to path loss and multipath fading, especially in urban deployments characterized by high-rise buildings and complex signal propagation environments. 5.0 conclusion based on the results obtained from the simulation and analysis, it is evident that adaptive filtering techniques significantly improve signal quality in urban lte networks. the comparison of sinr values before and after filtering clearly demonstrates enhanced signal integrity, with sinr improvements reaching over 2 db at certain measurement points. the bit error rate (ber) analysis shows that among the evaluated filters, the kalman filter consistently delivers the lowest ber values, highlighting its robustness in high-interference environments. the convergence analysis using mean square error (mse) further validates the efficiency of the kalman and rls filters, both of which achieve faster error reduction compared to the lms filter. additionally, the rsrp vs. distance plot illustrates the practical benefit of filtering, where signal levels after processing remain higher and more stable across various distances from the enodeb. these findings confirm that adaptive filtering, particularly using kalman and rls algorithms, is a viable and effective method for mitigating signal degradation due to interference, noise, and multipath fading in dense urban lte deployments. the study not only meets its objective of enhancing signal quality through measurement and analysis but also provides valuable insights for improving real-time signal processing in future lte-a and 5g networks. references [1] rojo-álvarez, j. l., martínez-ramón, m., muñoz-marí, j., & camps-valls, g. (2018). digital signal processing with kernel methods. hoboken, nj: john wiley & sons. [2] ali, s., saad, w., rajatheva, n., chang, k., steinbach, d., sliwa, b., wietfeld, c., mei, k., shiri, h., zepernick, h. j., et al. (2020). 6g white paper on machine learning in wireless communication networks. arxiv preprint arxiv:2004.13875. [3] khan, a. a., shah, s. m., raja, m. a. z., chaudhary, n. i., he, y., & machado, j. t. (2021). fractional lms and nlms algorithms for line echo cancellation. arabian journal of science and engineering, 46, 9385– 9398. https://doi.org/10.1007/s13369-020-05169-5 [4] zhu, z., gao, x., cao, l., pan, d., cai, y., & zhu, y. (2016). analysis on the adaptive filter based on lms algorithm. optik, 127, 4698–4704. https://doi.org/10.1016/j.ijleo.2016.01.145 mailto:topacademicjournals@gmail.com https://doi.org/10.1007/s13369-020-05169-5 https://doi.org/10.1016/j.ijleo.2016.01.145 academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [5] hakvoort, w. b., & beijen, m. a. (2023). filtered-error rls for self-tuning disturbance feedforward control with application to a multi-axis vibration isolator. mechatronics, 89, 102934. https://doi.org/10.1016/j.mechatronics.2022.102934 [6] wu, x., huang, z., & ji, y. (2020). deep neural network method for channel estimation in visible light communication. optics communications, 462, 125272. https://doi.org/10.1016/j.optcom.2020.125272 [7] mathews, a. b., & agees kumar, c. (2023). a non-linear improved cnn equalizer with batch gradient descent in 5g wireless optical communication. iete journal of research, 1– 13. https://doi.org/10.1080/03772063.2023.2186545 [8] wang, t., wen, c. k., wang, h., gao, f., jiang, t., & jin, s. (2017). deep learning for wireless physical layer: opportunities and challenges. china communications, 14, 92– 111. https://doi.org/10.1109/cc.2017.8246370 [9] el-saleh, a. a., alhammadi, a., shayea, i., hassan, w. h., honnurvali, m. s., & daradkeh, y. i. (2023). measurement analysis and performance evaluation of mobile broadband cellular networks in a populated city. alexandria engineering journal, 66, 927–946. https://doi.org/10.1016/j.aej.2022.10.014 [10] burmeister, f., schwarzenberg, n., höβler, t., & fettweis, g. (2021, march 29–april 1). measuring timevarying industrial radio channels for d2d communications on agvs. in 2021 ieee wireless communications and networking conference (wcnc) (pp. 1–7). ieee. https://doi.org/10.1109/wcnc49053.2021.9417580 [11] fink, a., mogensen, r. s., rodriguez, i., kolding, t., karstensen, a., & pocovi, g. (2021, november 10– 12). empirical performance evaluation of enterprise wi-fi for iiot applications requiring mobility. in 26th european wireless conference (pp. 1–8). vde. [12] lyczkowski, e., munz, h. a., kiess, w., & joshi, p. (2020, june 7–11). performance of private lte on the factory floor. in 2020 ieee international conference on communications workshops (icc workshops) (pp. 1–6). ieee. https://doi.org/10.1109/iccworkshops49005.2020.9145483 [13] schmieder, m., eichler, t., wittig, s., peter, m., & keusgen, w. (2020, march 15–20). measurement and characterization of an indoor industrial environment at 3.7 and 28 ghz. in 2020 14th european conference on antennas and propagation (eucap) (pp. 1–5). ieee. https://doi.org/10.23919/eucap48036.2020.9135556 mailto:topacademicjournals@gmail.com https://doi.org/10.1016/j.mechatronics.2022.102934 https://doi.org/10.1016/j.optcom.2020.125272 https://doi.org/10.1080/03772063.2023.2186545 https://doi.org/10.1109/cc.2017.8246370 https://doi.org/10.1016/j.aej.2022.10.014 https://doi.org/10.1109/wcnc49053.2021.9417580 https://doi.org/10.1109/iccworkshops49005.2020.9145483 https://doi.org/10.23919/eucap48036.2020.9135556 academic journal of science, engineering and technology vol. 10, issue 3; july-september 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset [14] mi, h., ai, b., he, r., wu, t., zhou, x., zhong, z., zhang, h., & chen, r. (2023). multi-scenario millimeter wave channel measurements and characteristic analysis in smart warehouse at 28 ghz. electronics, 12(15), 3373. https://doi.org/10.3390/electronics12153373 [15] raida, v., svoboda, p., koglbauer, m., & rupp, m. (2020, december 7–11). on the stability of rsrp and variability of other kpis in lte downlink–an open dataset. in globecom 2020–2020 ieee global communications conference (pp. 1–6). ieee. https://doi.org/10.1109/globecom42002.2020.9322356 [16] mahmud, i., lubna, t., & cho, y. z. (2022). performance evaluation of mptcp on simultaneous use of 5g and 4g networks. sensors, 22(19), 7509. https://doi.org/10.3390/s22197509 [17] github. (2024). measurement of 4g/5g mobile signal coverage in a heavy industry environment—the dataset. retrieved february 4, 2024, from https://github.com/polak-l/4g-5g-mobile-signal-coveragein-a-factory [18] shakir, z., mjhool, a. y., al-thaedan, a., al-sabbagh, a., & alsabah, r. (2023). key performance indicators analysis for 4g-lte cellular networks based on real measurements. international journal of information technology, 15, 1347–1355. https://doi.org/10.1007/s41870-023-01207-z a machine learning framework for predicting downlink throughput in 4g-lte/5g cellular networks. international journal of information technology, 16, 651–657. https://doi.org/10.1007/s41870-02401365-6 [20] nguyen, n. l., tu, l. t., nguyen, t. n., nguyen, p. l. t., & nguyen, q. s. (2023). performance on cognitive broadcasting networks employing fountain codes and maximal ratio transmission. radioengineering, 32(1), 1–10 mailto:topacademicjournals@gmail.com https://doi.org/10.3390/electronics12153373 https://doi.org/10.1109/globecom42002.2020.9322356 https://doi.org/10.3390/s22197509 https://github.com/polak-l/4g-5g-mobile-signal-coverage-in-a-factory https://github.com/polak-l/4g-5g-mobile-signal-coverage-in-a-factory https://doi.org/10.1007/s41870-023-01207-z https://doi.org/10.1007/s41870-024-01365-6 https://doi.org/10.1007/s41870-024-01365-6 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 33 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset effects of annealing heat treatment on the mechanical and microstructural characteristics of medium carbon steel. 1opara u.v, 2obiukwu o.o, 3nwufo o.c, 4ezeamaku l.u, 5ezeaku i.i, 6chiabuotu c.c, 7ekpechi d.a, 8okafor b.e. 1, 2, 3, 6, 7,8department of mechanical engineering, federal university of technology owerri, nigeria. 4department of polymer engineering, federal university of technology owerri, nigeria. 5department of mechanical engineering, abia state university, uturu, nigeria e-mail: ezeakuinnocentmnse@mail.com doi: https://doi.org/10.5281/zenodo.17176075 abstract: the mechanical behavior and performance of medium carbon steel can be profoundly modified through thermal processing. this study investigates the effect of annealing temperature on the mechanical and microstructural behaviour of medium carbon steel. test specimens were subjected to full annealing at various temperatures ranging from 600 °c to 850 °c, followed by controlled furnace cooling. mechanical properties such as tensile strength, yield strength, hardness, elongation, and impact toughness, were evaluated according to astm standards, while microstructural evolution was examined using optical microscopy. results showed that annealing temperature had a profound influence on material behavior. tensile and yield strengths decreased initially with rising temperature, reaching a minimum at 650 °c, but recovered progressively at higher temperatures. elongation and impact energy improved significantly with temperature up to an optimum point (700–750 °c), beyond which ductility and toughness declined, suggesting over-annealing effects. hardness followed a similar trend, with initial softening and subsequent partial recovery. microstructural analysis revealed a transformation from fine pearlite-ferrite in the as-received condition to coarser ferrite grains with spheroidized carbides at higher annealing temperatures. these findings underscore the critical role of annealing temperature in optimizing the balance between strength and ductility for enhanced processability and structural performance of medium carbon steel. keywords: annealing temperature, medium carbon steel, mechanical properties, microstructure, spheroidization, heat treatment. 1.0 introduction medium carbon steel remains one of the most commonly used engineering materials globally, because of its versatile mechanical properties, cost-effectiveness, and adaptability in a wide range of industrial applications [1]. among the various classifications of steel, medium carbon steel, typically containing 0.3% to 0.6% [2] carbon is mailto:topacademicjournals@gmail.com mailto:ezeakuinnocentmnse@mail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 34 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset mostly utilized for manufacturing engineering components such as shafts, gears, axles, crankshafts, connecting rods, and railway parts [ 3,4,5]. this category of steel strikes a balance between strength, hardness, and ductility, making it suitable for applications requiring moderate toughness and wear resistance. however, the as-received or hot-rolled form of medium carbon steel often contains residual stresses, non-uniform microstructures, and limited ductility, which can impede its machinability and formability. these drawbacks necessitate the use of heat treatment processes to tailor its properties to suit specific performance requirements. one such crucial heat treatment process is annealing [6, 7, 8]. annealing is a thermal treatment that involves heating the steel to a temperature above its critical transformation point (austenitizing temperature), holding it (soaking) for a specific duration to ensure homogeneity and then cooling it slowly usually within the furnace. annealing induces microstructural transformations that relieve internal stresses, refine grains, reduce hardness, and enhance ductility of a steel material. during this process, phase transformations and recovery phenomena occur, including recrystallization and grain growth, which ultimately influence the steel’s mechanical behavior [9]. the mechanical properties of steel, such as tensile strength, hardness, elongation, and impact toughness are intrinsically linked to its microstructure. factors such as grain size, phase distribution (ferrite and pearlite), dislocation density, and carbide morphology all change as a result of annealing [10, 11, 12]. understanding how these microstructural features evolve during heat treatment provides valuable insights into controlling the mechanical properties of steel for engineering applications [13, 14, 15, 16]. previous researchers have addressed the general effects of heat treatments on carbon steels. however, there remains a need for more focused and quantitative analysis of how varying soaking times and annealing temperature during annealing influence the mechanical and microstructural characteristics of medium carbon steel. soaking time plays a crucial role in diffusion, grain growth, and homogenization, all of which directly affect the outcome of the treatment [17]. excessive soaking can lead to undesirable grain coarsening, while insufficient soaking may leave residual stresses unrelieved. in industrial settings, where component reliability, safety, and performance are critical, precise knowledge of how annealing conditions affect material behavior can inform decisions about processing parameters and material selection. this becomes even more pertinent in manufacturing sectors such as automotive, railway, oil and gas, and heavy machinery, where medium carbon steel is often subjected to machining, forming, and cyclic loading. 2.0 materials and methods. 2.1 material composition the material investigated in this study is a commercial-grade medium carbon steel, containing 0.352% carbon, and is specifically designed for heat treatment. the full chemical composition is presented in table 1, as determined using optical emission spectroscopy. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 35 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 1: the full chemical composition of the commercial-grade medium carbon steel. 2.2 sample preparation the medium carbon steel bar as-received was machined into standard test specimens for mechanical testing such as tensile, impact, and hardness tests in accordance with astm standards. additional specimens were prepared for metallographic analysis. all the samples were surface cleaned to get rid of oxides and contaminants before heat treatment. 2.3 heat treatment the test specimens labelled as sample a, b and c were subjected to annealing heat treatment after which the surface characterization and mechanical test were conducted. the heat treatment process was done in a carbolite muffle furnace. 2.3.1 annealing procedure annealing is a heat treatment process used to soften metals, improve their machinability, and reduce internal stresses. the annealing process was carried out using the muffle furnace. the test samples were meticulously cleaned to eliminate any surface contaminants or oxides to ensure optimal results. the muffle furnace was then set to the appropriate temperature range for medium carbon steel annealing, ranging between 600°c to 850°c. gradual heating of the test samples commenced, allowing the samples to reach the designated annealing temperature gradually. throughout this process, precise temperature control was maintained within the furnace s/n elements weight % 1 c 0.352 2 si 0.148 3 mn 0.524 4 p 0.044 5 s 0.055 6 cr 0.224 7 mo 0.104 8 ni 0.104 9 cu 0.250 10 v 0.006 11 nb < 0.0002 12 n 0.0013 13 b 0.0028 14 al 0.0036 15 sn 0.030 16 fe 98.241 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 36 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset to ensure uniform heating and prevent overheating or underheating of the test samples. when the annealing temperature was reached, the samples were held at that temperature for the recommended duration, typically ranging from 30 minutes to 2 hours. this soaking period allowed for the transformation of the medium carbon steel's microstructure, relieving internal stresses and promoting softening. following the annealing cycle, the furnace was gradually cooled down along with the work pieces to prevent rapid cooling and minimize the risk of thermal shock. after reaching a safe handling temperature, the annealed samples were carefully removed from the furnace and inspected for desired annealing effects, such as reduced hardness and improved machinability. 2.4 mechanical testing mechanical testing was conducted to determine the effect of annealing heat treatment on the mechanical behavior of medium carbon steel. the mechanical tests carried out include tensile testing, hardness measurement, and impact toughness evaluation, all performed in accordance with relevant astm standards. 2.4.1 tensile testing after the annealing heat treatment process, the various heat-treated samples were subjected to tensile test, using the standard universal testing machine. tensile testing was conducted following the astm standard using a universal testing machine with a maximum load capacity of 100 kn. standard round tensile specimens with a gauge length of 50 mm and a diameter of 12.5 mm were machined and properly aligned in the machine’s grips. the load was applied axially at a constant crosshead speed of 2 mm/min until the specimen fractured. during the test, data which include tensile strength, yield strength, and percentage elongation were recorded. figure 1: universal instron machine (modell 3369, maker instron) 2.4.2 hardness testing: hardness testing was conducted using the rockwell hardness tester following the astm standard. each of the specimens were prepared by grinding and polishing to obtain a smooth and clean surface. using the c-scale, a mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 37 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset minor load of 10 gf was first applied, followed by a major load of 150 kgf using a diamond cone (brale) indenter. after the required dwell time, the major load was released and the hardness value was read directly from the dial. three hardness measurements were taken at different points on each sample, and the average value was reported to ensure accuracy and repeatability. 2.4.3 impact testing impact toughness was evaluated using the charpy v-notch test in accordance with astm. standard specimens measuring 10 mm × 10 mm × 55 mm were machined with a centrally located 2 mm deep v-notch. each specimen was placed on the charpy impact tester’s anvil with the notch facing away from the pendulum. the pendulum hammer was released to strike the specimen at the notch, and the energy absorbed during fracture was recorded in joules. three samples were tested under each condition, and the average impact energy was used for analysis. 2.4.4 elongation the elongation of the medium carbon steel specimens was determined during the tensile test in accordance with astm. before testing, the gauge length of each specimen was carefully marked and measured using a calibrated micrometer. the specimen was then mounted in the grips of a universal testing machine, and a uniaxial tensile load was applied at a constant crosshead speed of 2 mm/min until the specimen fractured. after fracture, the two broken pieces were carefully fitted back together, and the final gauge length between the original gauge marks was measured using a vernier caliper or micrometer. the percentage elongation was then calculated using the formula: elongation (%) = 𝐿𝑓 −𝐿0 𝐿0 x 100 where 𝐿𝑓 is the final gauge length after fracture and 𝐿0 is the original gauge length before the test. the result provides an indication of the material’s ductility, and the average value from at least three specimens was reported to ensure accuracy and repeatability. 2.4.5 yield strength. the yield strength of the medium carbon steel specimens was determined using a universal testing machine in accordance with astm. standard round tensile specimens were prepared with a gauge length of 50 mm and mounted securely in the machine. a uniaxial tensile load was applied at a constant crosshead speed of 2 mm/min, and the load-extension data were recorded continuously. the yield load was divided by the original cross-sectional area of the specimen to calculate the yield strength in mpa. the average value from three test replicates was reported. yield strength (𝛿𝑦) = 𝑃𝑦 𝐴0 where 𝑃𝑦 = load at yield point (n) 𝐴0 = original cross sectional area of gauge length (𝑚𝑚2) 2.5 metallographic characterization mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 38 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset microstructural examination of the as-received and annealed specimens was carried out using the accuscope metallurgical microscope. each sample was carefully ground progressively on emery paper in decreasing coarseness. the grinding surface of the samples were polished using al2 o3 carried on a micro clothe. the crystalline structure of the specimens was made visible by etching using solution containing 2% nitric acids and 98% methylated spirit on the polished surfaces. microscopic examination of the etched surface of various specimens was undertaken using a metallurgical microscope with an inbuilt camera through which the resulting microstructure (grain distribution morphology and phase distribution) of the samples were all photographically recorded with magnification of 400. 3.0 results and discussion 3.1 microstructural view of the samples before and after annealing heat treatment. fig 2. the samples as-received exhibited fine pearlite-ferrite microstructures with lamellar morphology. the dark region, which is more on the micrograph is pearlite (a lamellar (layered) mixture of two phases: ferrite (α-iron, a relatively soft and ductile phase with low carbon solubility) and cementite (fe₃c, a hard and brittle iron carbide) and the white region (not too many) is ferrite. figure 2: the microstructural view of the test material asreceived. it shows that the as-received samples exhibit pearlite lamella morphology that will lead to undesirable mechanical properties in high stressed applications. figure 3 shows the microstructural view of the material after annealing. the annealing process transformed the microstructure of the medium carbon steel test sample, significantly impacting its mechanical properties. the annealing process metamorphosed the pearlite and ferrite nature of the received samples due to thermal exposure. the thermal exposure during annealing promotes the existing ferrite grains to enlarge (the transformation from lamellar pearlite to dispersed spheroidal carbides within a matrix of larger ferrite grains). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 39 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 3: microstructural view of the annealed samples. the larger ferrite grains with fewer grain boundaries offers less resistance to dislocation movement within the material's crystal structure. this translates to a softer and more workable material. also, spheroidization, which is the key transformation that occurs within the pearlite region. the iron carbide (fe3c) lamellae gradually morph into spheroidal (rounded) particles. this process, driven by time and temperature, significantly alters the pearlite's morphology the spheroidized carbides, compared to the sharp lamellae, offers less resistance during deformation, further enhancing the ductility. of the material. 3.2 results of the effect of annealing temperature on the mechanical behavior of the test samples. figure 4 shows the "effect of annealing temperature on tensile strength of the test materials" it shows how the tensile strength of the three different samples (sample a, sample b, and sample c) changes with varying annealing temperatures.it can be seen that at 600°c, all three samples started with a tensile strength of approximately 490 mpa. as the temperature increases from 600°c to 650°c, there is a noticeable decrease in tensile strength for all samples, reaching a minimum at around 650°c.the lowest tensile strength for all samples is around 460 mpa. beyond 650°c, the tensile strength begins to recover and increases steadily up to 850°c.all samples show a similar trend in recovery, with tensile strength increasing back to about 490 mpa at 800°c and continuing to rise slightly above 490 mpa by 850°c. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 40 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: effect of annealing temperature on tensile strength of the test samples. the graph indicates that annealing at temperatures between 600°c and 650°c reduces the tensile strength of the materials, possibly due to microstructural changes like grain growth or phase transformations. after 650°c, the tensile strength increases, indicating that higher annealing temperatures (above 650°c up to 850°c) are beneficial for recovering and even enhancing the tensile strength of the materials. this shows that annealing temperature significantly influences the tensile strength of the test materials, with a dip around 650°c and a gradual recovery and enhancement as the temperature increases up to 850°c. figure 5: effect of annealing temperature on yield strength of the test samples. the effect of annealing temperature on yield strength of the test materials is shown in figure 5. it shows how the yield strength of the three different samples (sample a, sample b, and sample c) changes with varying annealing temperatures. it can be seen that at 600°c, all three samples started with a yield strength of approximately 350 mpa. as the temperature increases from 600°c to 650°c, there is a noticeable decrease in yield strength for all samples, reaching a minimum at around 650°c. the lowest yield strength for all samples is around 320 mpa. beyond 650°c, the yield strength begins to recover and increases steadily up to 850°c. all 440 450 460 470 480 490 500 600 650 700 750 800 850 t e n s il e s t r e n g h t ( m p a ) temperature (℃) sample a sample b sample c 310 320 330 340 350 360 370 600 650 700 750 800 850 900y ie ld s tr en g h t (m p a) temperature (℃) sample a sample b sample c mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 41 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset samples show a similar trend in recovery, with yield strength increasing back to about 350 mpa at 800°c and continuing to rise slightly above 360 mpa by 850°c. the graph indicates that annealing at temperatures between 600°c and 650°c reduces the yield strength of the materials, possibly due to microstructural changes like grain growth or phase transformations. after 650°c, the yield strength increases, indicating that higher annealing temperatures (above 650°c up to 850°c) are beneficial for recovering and even enhancing the yield strength of the materials. this shows that annealing temperature significantly influences the yield strength of the test materials, with a dip around 650°c and a gradual recovery and enhancement as the temperature increases up to 850°c. figure 6: effect of annealing temperature on the elongation of the test samples. figure 6. shows the "effect of annealing temperature on the elongation of the test materials." it shows how the elongation of the three different samples (sample a, sample b, and sample c) changes with varying annealing temperatures. it can be seen that at 600°c, all three samples started with an elongation of approximately 24-26%. as the temperature increases from 600°c to 650°c, there is a noticeable increase in elongation for all samples. the elongation peaks around 700°c, beyond 700°c, the elongation begins to decrease steadily up to 850°c. the graph indicates that annealing at temperatures between 600°c and 700°c increases the elongation of the materials, possibly due to microstructural changes like grain growth that enhance ductility. after 700°c, the elongation decreases, suggesting that higher annealing temperatures (above 700°c up to 850°c) may lead to over-annealing, resulting in reduced ductility. this shows that annealing temperature significantly influences the elongation of the test materials, with an increase in ductility up to 700°c and a gradual decrease as the temperature increases further to 850°c. 20 22 24 26 28 30 32 34 600 650 700 750 800 850 900 el o n g a ti o n ( % ) temperature (℃) sample a sample b sample c mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 42 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 7: effect of annealing temperature on impact toughness of the test samples. fig 7. shows the "effect of annealing temperature on impact toughness of the test materials." it shows how the impact toughness of the three different samples (sample a, sample b, and sample c) changes with varying annealing temperatures. it can be seen that at 600°c, all three samples started with an impact toughness of approximately 45 joules. as the temperature increases from 600°c to 750°c, there is a noticeable increase in impact toughness for all samples. beyond 750°c, the impact toughness begins to decrease steadily up to 850°c. at 850°c, the graph indicates that annealing at temperatures between 600°c and 750°c increases the impact toughness of the materials, possibly due to microstructural changes like grain growth that enhance toughness. after 750°c, the impact toughness decreases, suggesting that higher annealing temperatures (above 750°c up to 850°c) may lead to over-annealing, resulting in reduced toughness. this shows that annealing temperature significantly influences the impact toughness of the test materials, with an increase in toughness up to 750°c and a gradual decrease as the temperature increases further to 850°c. 40 45 50 55 60 65 600 650 700 750 800 850 900 im p a c t to u g h n es s (j o u le s) temperature (℃) sample a sample b sample c mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 43 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 8: effect of annealing temperature on the hardness of the test samples. figure 8. shows the "effect of annealing temperature on the hardness of the test materials." it shows how the hardness of the three different samples (sample a, sample b, and sample c) changes with varying annealing temperatures. it can be seen that at 600°c, all three samples started with a hardness of approximately 74hrb. as the temperature increases from 600°c to 650°c, there is a noticeable decrease in hardness for all samples, reaching a minimum at around 650°c. beyond 650°c, the hardness begins to recover and increases steadily up to 850°c. the graph indicates that annealing at temperatures between 600°c and 650°c reduces the hardness of the materials, possibly due to microstructural changes such as grain growth or phase transformations. after 650°c, the hardness increases, indicating that higher annealing temperatures (above 650°c up to 850°c) are beneficial for recovering and even enhancing the hardness of the materials. this shows that annealing temperature significantly influences the hardness of the test materials, with a dip around 650°c and a gradual recovery and enhancement as the temperature increases up to 850°c. 4.0 conclusion the study revealed that annealing temperature has a significant influence on the mechanical and microstructural characteristics of medium carbon steel. as the annealing temperature increased from 600 °c to 850 °c, both tensile and yield strengths initially declined due to microstructural coarsening and stress relief, reaching their lowest values around 650 °c. however, a progressive recovery in strength was observed at higher temperatures, particularly beyond 700 °c. conversely, ductility and impact toughness improved with increasing temperature, reaching optimum levels around 700 °c to 750 °c, after which a slight reduction was observed, indicating the onset of over-annealing. microstructural examination confirmed the transformation from fine pearlite-ferrite 60 62 64 66 68 70 72 74 76 78 80 600 650 700 750 800 850 900 h a r d n es s (h r b ) temperature (℃) sample a sample b sample c mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 44 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset lamellae in the as-received samples to coarser, equiaxed ferrite grains with spheroidized carbides at elevated temperatures. these changes facilitated improved plasticity and reduced resistance to deformation. overall, the findings establish that the annealing temperature range of 700 °c to 750 °c is optimal for achieving a balance between improved ductility and adequate strength, making it suitable for applications requiring enhanced formability and moderate mechanical performance. controlled annealing within this temperature window can therefore be employed to tailor medium carbon steel for use in structural, automotive, and manufacturing components. references boumediri, h., touati, s., debbah, y., selami, s., chitour, m., khelifa, m., ... & fernandes, f. (2024). effect of carburizing time treatment on microstructure and mechanical properties of low alloy gear steels. materials research express, 11(7), 076505. hernandez-duran, e., corallo, l., ros-yanez, t., castro-cerda, f., & petrov, r. h. (2021). the effect of different annealing strategies on the microstructure development and mechanical response of austempered steels. metals, 11(7), 1041. hernandez-duran, e. i., ros-yanez, t., castro-cerda, f. m., & petrov, r. h. (2020). the influence of the heating rate on the microstructure and mechanical properties of a peak annealed quenched and partitioned steel. materials science and engineering: a, 797, 140061. https://doi.org/10.1016/j.msea.2020.140061 kandpal, b. c., gupta, d. k., kumar, a., jaisal, a. k., ranjan, a. k., srivastava, a., & chaudhary, p. (2021). effect of heat treatment on properties and microstructure of steels. materials today: proceedings, 44, 199–205. kang, t., zhan, z., wang, c., zhao, z., liang, j., & yao, l. (2024). microstructure evolution and tensile properties of medium manganese steel heat treated by two-step annealing. metals, 14(9), 1008. lü, z. q., zhang, h. f., meng, q., wang, z. h., & fu, w. t. (2016). effect of cyclic annealing on microstructure and mechanical properties of medium carbon steel. journal of iron and steel research international, 23(2), 145–150. miftah, e. (2025). the impact of heat treatment on hardness and corrosion resistance of medium carbon steel. international journal of electrical engineering and sustainability, 47–57. murmu, s., chaudhary, s. k., & rajak, a. k. (2022). effect of heat treatment on mechanical properties of medium carbon steel welds. materials today: proceedings, 56, 964–970. mailto:topacademicjournals@gmail.com https://doi.org/10.1016/j.msea.2020.140061 academic journal of science, engineering and technology vol.10, issue 3; july-august 2025 issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 45 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset opara, u. v., obiukwu, o. o., nwufo, o. c., ezeaku, i. i., chiabuotu, c. c., ezeamaku, l. u., ekpechi, d. a., & okafor, b. e. (2025). tempering heat treatment impact on medium carbon steel: microstructure and mechanical behaviour. the international journal of engineering and science (ijes), 14(7), 34–42. https://doi.org/10.9790/1813-14073442 orhorhoro, e. k., erameh, a. a., & okuma, s. o. (2022). investigation of the mechanical properties of annealing heat treated low carbon steel. algerian journal of engineering and technology, 6(1), 29–36. ravindran, m., aswatha, m., santhosh, n., ravichandran, g., & madhusudhan, m. (2021). effect of heat treatment on fatigue characteristics of en8 steel. in iop conference series: materials science and engineering (vol. 1013, no. 1, p. 012009). iop publishing. senthilkumar, t., & ajiboye, t. k. (2012). effect of heat treatment processes on the mechanical properties of medium carbon steel. journal of minerals and materials characterization and engineering, 11(2), 143–152. shin, b., kim, k., yi, s., choi, s., & hyun, s. (2021). microstructure and mechanical properties of cast and hotrolled medium-carbon steels under isothermal heat-treatment conditions. metals, 11(12), 1950. skowronek, a., radwański, k., sozańska-jędrasik, l., matus, k., & grajcar, a. (2025). continuous annealing of medium-mn steels: sensitivity of mechanical performance to minor changes in time-temperature heat treatment parameters. materials science and engineering: a, 940, 148568. https://doi.org/10.1016/j.msea.2025.148568 soleimani, m., mirzadeh, h., & dehghanian, c. (2021). effects of spheroidization heat treatment and intercritical annealing on mechanical properties and corrosion resistance of medium carbon dual phase steel. materials chemistry and physics, 257, 123721. yuan, s., xie, h., ren, m., lin, f., zhu, l., liang, x., ... & jiang, z. (2025). effects of annealing temperature on the microstructure, mechanical properties, and tribological performance of the mn8/ss400 bimetal composite. tribology international, 204, 110536. zhu, k., zhu, x., xu, r., tong, s., liang, x., sun, x., & yang, c. (2025). effect of rapid heat treatment on mechanical properties and precipitation behavior of medium carbon low alloy steel. journal of materials research and technology, 35, 5730–5745. mailto:topacademicjournals@gmail.com https://doi.org/10.9790/1813-14073442 https://doi.org/10.1016/j.msea.2025.148568 academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset assessment of property management for the development of real estate business in enugu urban nigeria nwanna isaac arinze, prof augusta emenike and eze hillary department of quantity surveying, faculty of environmental sciences esut business school, enugu state university of science and technology, enugu doi: https://doi.org/10.5281/zenodo.14974498 abstract: the study examined the effect of assessment of property management on the development of real estate business in enugu urban nigeria. the specific objectives are to; examine the effect of energy efficiency management on the development of real estate business. evaluate the effect of conserving water management on the development of real estate business in enugu urban nigeria. the study adopts a descriptive survey research design. primary data collection from a cross-section of respondents through a structured questionnaire. the population of this study consists of real estate developers, property managers, and other stakeholders involved in the real estate business in enugu state. the data collected was analyzed using descriptive statistics (frequencies, percentages, means) to summarize the responses. the hypotheses were tested using inferential statistical techniques such as regression analysis, correlation, and statistical package for social sciences (spss) version 28.0. the result revealed that energy efficiency management has a significant effect on the development of real estate business where the p-value is (0.000<0.05) and conserving water management has a significant effect on the development of real estate business where the p-value is (0.001<0.05) in enugu urban nigeria. the study concluded that sustainable property management has a significant effect on the development of real estate business in enugu urban nigeria. the study recommended among others that, real estate developers and property managers should actively adopt and promote energy-efficient technologies and practices, such as the use of renewable energy sources, led lighting, energy-efficient appliances, and insulation systems. keywords: development, estate, management, property, real 1.1 introduction sustainable property management (spm) is increasingly recognized as a vital component of modern real estate practices, driving significant changes in how properties are developed, maintained, and operated (dixon, et al. 2019). as the real estate sector grapples with the challenges of climate change, resource scarcity, and evolving consumer expectations, adopting sustainable practices has become essential for long-term success. spm encompasses a range of strategies to reduce the environmental impact of buildings, optimize resource use, and enhance the social and economic value of real estate assets (cohen, & nussbaum, 2018). the development of real estate businesses through spm addresses environmental concerns and offers substantial economic benefits. by mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset implementing energy-efficient technologies, sustainable materials, and environmentally responsible practices, property managers can reduce operational costs, increase the longevity of assets, and boost property values (cohen, & nussbaum, 2018). additionally, properties managed sustainably tend to attract more investors, tenants, and buyers who are increasingly conscious of environmental and social issues (baker, 2019). regulatory pressures also drive this shift towards sustainability in property management, as governments around the world introduce stricter environmental standards and incentives for green building practices (elahee, 2019). real estate businesses that embrace spm are better positioned to comply with these regulations, avoiding potential penalties and gaining a competitive edge in the market. sustainable property management (spm) has emerged as a pivotal aspect of the real estate industry, particularly in the context of developing economies like nigeria (hopkins 2023). enugu state, located in the southeastern region of nigeria, is witnessing a burgeoning real estate sector driven by urbanization, population growth, and increased investment. however, the rapid expansion of real estate in enugu state has brought to the forefront the need for sustainable practices to mitigate environmental degradation, enhance social responsibility, and ensure long-term economic viability (elahee, 2019). spm in enugu state involves the integration of eco-friendly practices, efficient resource utilization, and the adoption of green building technologies to create properties that meet the needs of present and future generations (hopkins 2023). this approach not only addresses environmental concerns but also contributes to the economic and social aspects of development, fostering balanced growth in the real estate sector. the development of real estate businesses in enugu urban, enugu state through sustainable property management practices is crucial for several reasons (elahee, 2019). it enhances property values, reduces operational costs, and increases the attractiveness of investments. furthermore, it aligns with global trends toward sustainability, making the local real estate market more competitive on an international scale. this study explores the impact of sustainable property management on the development of the real estate business in enugu urban, examining how these practices influence property values, investment decisions, and overall market growth. by highlighting the benefits and challenges of adopting spm, the study aims to provide insights that can guide policymakers, real estate developers, and investors in fostering a sustainable and thriving real estate industry in enugu urban. 1.2 statement of the problem despite the growing recognition of the importance of sustainability in global real estate markets, the adoption of sustainable property management (spm) practices in enugu urban, nigeria, remains limited. the real estate sector in enugu urban is rapidly expanding due to increasing urbanization, population growth, and rising demand for housing and commercial properties. however, this growth has often been accompanied by environmentally unsustainable practices, such as inefficient resource use, inadequate waste management, and reliance on nonrenewable energy sources. these practices not only contribute to environmental degradation but also pose longterm risks to the economic viability and competitiveness of real estate businesses in the region. the reluctance to fully integrate spm practices into the real estate sector in enugu urban can be attributed to several factors, including lack of awareness, insufficient regulatory frameworks, and perceived high costs of mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset implementation. as a result, many real estate businesses continue to operate using traditional methods that may yield short-term profits but are ultimately unsustainable. this raises critical questions about the future development of the real estate industry in enugu urban, particularly in the context of global trends towards sustainability and the increasing demand for eco-friendly properties. the problem, therefore, is the insufficient adoption of sustainable property management practices in enugu urban, which hampers the sustainable development of the real estate sector. this study seeks to investigate the extent to which spm practices are being implemented, the barriers to their adoption, and their impact on the growth and sustainability of real estate businesses in enugu urban. understanding these dynamics is crucial for developing strategies that can promote the widespread adoption of spm, thereby enhancing the long-term success and environmental responsibility of the real estate sector in the region. 1.3 objective of the study the main objective of this study is to examine the assessment of property management on the development of real estate business in enugu urban. nigeria. the specific objectives are to; i. examine the effect of energy efficiency management on the development of real estate business in enugu urban nigeria. ii. evaluate the effect of conserving water management on the development of real estate business in enugu urban nigeria. 1.4 hypotheses of the study i. energy efficiency management has no significant effect on the development of real estate business in enugu urban nigeria. ii. conserving water management has no significant effect on the development of real estate business in enugu urban nigeria 2.0 review of related literature 2.1 conceptual review 2.1.1 sustainable property management sustainable property management is the holistic approach to managing properties to minimize their environmental impact while maximizing their social and economic benefits. sustainable property management (spm) is implementing green building initiatives during the operations and maintenance phase of the building lifecycle, taking into account their environmental, social, and economic impacts to reconcile these three spheres in such a way that a balance is achieved between economic development and the protection of environmental and social resources, hopkins, (2023). according to dixon et al. (2019), spm integrates sustainability into every aspect of property management, including design, construction, operation, and maintenance. the core principles of spm include resource efficiency, waste reduction, social equity, and economic viability (cohen & nussbaum, 2018). according to oladokun (2010), property management is a comprehensive subject that requires the application of skills and knowledge to exploit the potential value of real estate assets. the main aim of property management is to maximize the owner’s investment for maximum return through the application of appropriate skills in caring mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset for the property. property managers are employed by property owners to perform the management of their properties based on their training. sustainable property management simply implies locating, designing, developing, and handling property that is economically viable, environmentally friendly, and has a positive and significant impact on the quality of life of the inhabitants and the environment at large. (keeping & shiers, 2004). lutzkendorf and lorenz (2007) classified sustainable buildings and their management, in terms of overall areas of protection, which can be understood from the three dimensions of sustainable development; protection of the natural environment/ecosystem; protection of basic natural resources; protection of human health and welfare; protection of social values and public goods; protection and preservation of capital and tangible property. this was further revealed by the royal institution of chartered surveyors (2009), that sustainable building management envisages a minimized building life cycle costs by analyzing all building-related impacts, from raw material extraction to manufacturing, use, repair, maintenance, disposal, and recycling. sustainable property management practices have been beneficial in making buildings more readily leased, commanding higher rents, and having higher tenant retention rates; generally, enjoy lower operating costs through increasing energy efficiency and lessening greenhouse gas emissions; improve business productivity of their tenants, affecting churn, renewals, inducements and fitting-out costs; and benefit occupants to a degree that may exceed the underlying asset's value, oladokun, (2010). 2.1.2 energy efficiency management energy management is the proactive, organized, and systematic coordination of procurement, conversion, distribution, and use of energy to meet the requirements, considering environmental and economic objectives. it is a systematic endeavor to optimize energy efficiency for specific political, economic, and ecological objectives through engineering and management techniques, (elahee, 2019). energy efficiency management (eem) encompasses the systematic approach to managing energy use to maximize productivity while minimizing waste. as defined by the international energy agency (iea, 2021), eem involves strategies that integrate technology, behavior modification, and organizational practices to enhance energy use efficiency. energy efficiency management represents a crucial strategic practice aimed at elevating the performance of commercial and industrial structures to the highest levels through the utilization of innovative technologies, intelligent strategies, and sustainable work methods. it aims to reduce unnecessary energy consumption, enhance the efficient utilization of energy, lower operational costs, and reduce carbon emissions significantly. implementing energy efficiency management involves several strategies, (baker, 2019). one of the most effective methods is conducting energy audits. these audits assess how energy is being used in buildings and processes, identifying areas where energy savings can be achieved, (baker, 2019). another strategy is the adoption of advanced technologies. smart meters, energy management systems, and energy-efficient appliances are examples of technologies that can significantly reduce energy consumption (khan& khan, 2021). moreover, retrofitting existing infrastructures with energy-efficient systems can also yield substantial benefits. employee engagement and training are essential components of energy efficiency management. organizations can foster a culture of energy awareness by educating employees about energy-saving practices and encouraging mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset them to participate in energy conservation efforts (morrissey & hennelly, 2020). energy efficiency management is a multifaceted approach that contributes to environmental sustainability and enhances economic performance and energy security. 2.1.3 conserving water management water is a vital resource for sustaining life, economic development, and environmental health. as global populations grow and climate change exacerbates water scarcity, effective water management becomes increasingly crucial. conserving water management refers to the strategies and practices implemented to reduce water consumption, enhance water efficiency, and ensure sustainable use of this precious resource. conserving water management encompasses a range of strategies that are essential for sustainable development. by integrating technological, behavioral, and policy approaches, it seeks to mitigate water scarcity and promote responsible water use, (hoekstra and chapagain 2007). the significance of conserving water management cannot be overstated. as populations increase and urbanization accelerates, the water demand continues to rise. this trend places immense pressure on freshwater resources, leading to over-extraction and degradation of ecosystems. implementing effective water conservation strategies can help mitigate these challenges, ensuring that water remains available for future generations. furthermore, conserving water management has economic implications. reducing water use can lead to significant cost savings for households and businesses. for instance, the implementation of water-efficient technologies can lower utility bills, while conservation policies can reduce the need for costly infrastructure investments to expand water supply systems (mayer et al., 2008). one of the primary elements of conserving water management is the adoption of water-efficient technologies. innovations in irrigation systems, plumbing fixtures, and industrial processes can lead to substantial reductions in water use. for instance, drip irrigation systems, which deliver water directly to plant roots, can use up to 60% less water than traditional methods (fereres & soriano, 2007). additionally, the installation of low-flow faucets and toilets in residential and commercial buildings can significantly decrease overall water consumption. behavioral change is another critical aspect of water conservation. educating individuals and organizations about the importance of water-saving practices can foster a culture of conservation. initiatives such as public awareness campaigns and community workshops can effectively encourage people to adopt water-saving habits, such as fixing leaks, using water-efficient appliances, and reducing outdoor water use (mayer et al., 2008). policy and regulation are essential tools in promoting conserving water management. governments can implement policies that incentivize water conservation, such as subsidies for water-efficient appliances or penalties for excessive water use. regulations can also be established to limit water consumption in sectors known for high usage, such as agriculture and manufacturing (grafton et al., 2011). by promoting sustainable water use, communities can enhance their resilience to climate variability and ensure long-term economic stability. 2.1.4 real estate business real estate development refers to the process of improving land or properties to maximize their value, which can include residential subdivisions, commercial centers, and mixed-use developments. this aspect of real estate requires significant planning, financing, and compliance with regulatory frameworks (chin & chau, 2003). the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset real estate business encompasses the buying, selling, leasing, and management of properties, including residential, commercial, and industrial real estate. this sector plays a crucial role in the economy, influencing job creation, wealth accumulation, and urban development. understanding the dynamics of the real estate business requires an exploration of its key components, market influences, and the various stakeholders involved. at its core, the real estate business consists of several key activities: brokerage, property management, development, investment, and financing. real estate brokers facilitate transactions between buyers and sellers, providing valuable market insights and negotiating deals. property management involves overseeing rental properties, ensuring they are maintained and profitable, while also managing tenant relationships (baker & sirmans, 2005). the real estate market is influenced by a variety of factors, including economic conditions, interest rates, demographic trends, and government policies. economic indicators such as employment rates, gdp growth, and inflation can significantly impact demand for real estate (haurin, parcel, & haurin, 2004). for instance, during periods of economic growth, demand for housing and commercial spaces typically rises, driving prices upward. conversely, economic downturns can lead to decreased demand and falling prices. interest rates also play a crucial role in the real estate business. lower interest rates often lead to increased borrowing, making it easier for individuals and businesses to finance property purchases (mishkin, 2015). the real estate business involves a diverse range of stakeholders, each with distinct interests and roles. these include real estate agents, developers, investors, tenants, and government entities. each stakeholder contributes to the overall functioning of the market and influences its direction. the real estate business is a dynamic and multifaceted sector that plays a vital role in the economy. by understanding its key components, market influences, and the various stakeholders involved, one can appreciate the complexities of real estate transactions and the factors that drive market trends. as urbanization continues and economic conditions evolve, the real estate business will remain a critical area of focus for investors, policymakers, and consumers alike, (rosen and gyourko, 2001). 2.2 theoretical review 2.2.1 resource-based view (rbv) originally proposed by birger wernerfelt (1984), later developed and refined by jay b. barney (1991) and other scholars, the resource-based view of the firm has found considerable support in the business literature. a major premise of the resource-based theory is that competitive advantage is a function of the resources and capabilities of the firm (wernerfelt, 1984; peteraf, 1993). valuable resources help a firm exploit opportunity and/or avoid threats in the environment (barney, 1991) and enable it to develop and/or implement strategies to improve its efficiency and effectiveness. when we discuss the value of a resource, it is important to ask, ‘valuable to whom'. according to the resource-based view (rbv) of the firm, a company can outperform other companies by the way the company combines its technical, human, and other resources. the resource-based view also advances the importance of firm-specific resources, that is, those resources that maintain value in the context of the given firm's markets and other resources that are difficult to replicate by other firms (wernerfelt 1984). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.3 empirical reviews pahl-wostl (2007) conducted a study to emphasize the need for a transition from traditional, rigid water management practices to more flexible, adaptive management approaches that can better cope with uncertainty and change in europe. the study aims to explore the concept of adaptive water management and its relevance in the face of global environmental changes. a qualitative research approach was used. the results revealed that there is a significant need for the integration of adaptive management principles into national and international water policies, emphasizing that such a transition is critical for managing the risks associated with climate change. thollander et al (2007) conducted a study to evaluate local energy programs for manufacturing smes, focusing on energy efficiency management within small and medium-sized enterprises (smes) in the industrial sector of sweden. the study aims to evaluate the effectiveness of a local energy program designed to enhance energy efficiency in manufacturing smes in sweden. the study employed both quantitative and qualitative approaches for this study. the results revealed that the local energy program led to an average reduction of 12% in energy consumption across the participating smes hence improving energy efficiency. dagnino and ward (2012) conducted a study to examine the adoption of efficient irrigation techniques in agricultural water management, focusing on drip irrigation systems in a semi-arid region. this study aims to analyze water conservation practices in irrigated agriculture in a sub-basin in north america's rio grande of mexico. the study utilized a longitudinal survey. the results revealed that where water rights exist, water rights administrators will need to guard against increased depletion of the water source in the face of growing subsidies for drip irrigation. halim, amir, and masri (2017) conducted a study to identify the key areas where energy efficiency can be improved within the academic buildings of the engineering campus in malaysia. the study aims to evaluate the effectiveness of energy-saving measures within an academic setting, providing a comprehensive overview of the strategies used and the results achieved at the engineering campus of university sains malaysia. a case study approach was employed for this study. the results revealed that the implementation of the energy efficiency improvement and management program led to a significant reduction in energy consumption. 3. methodology 3.1 study area the study is conducted in enugu state, nigeria, a major urban center with a growing real estate industry. enugu state, located in the southeastern region of nigeria, is a prominent urban center with a rich history and significant economic activities. the state capital, enugu, often referred to as the "coal city," serves as a hub for commercial, political, and industrial activities, making it one of the key cities in the region. in recent years, enugu has witnessed considerable growth in its real estate sector, driven by population growth, urbanization, and increasing demand for residential, commercial, and industrial properties. the rapid development of property markets in enugu state is evident in the surge of new housing projects, commercial centers, and mixed-use developments. this urban expansion is accompanied by an increasing focus on sustainability, particularly in the realms of energy efficiency, water conservation, and environmentally friendly building practices. the state government, alongside mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset private developers, has begun embracing sustainable construction technologies and policies aimed at reducing the environmental impact of urban development. these initiatives reflect a broader trend toward adopting green building practices, which aim to minimize resource consumption and enhance the overall sustainability of infrastructure in the area. 3.2 research design this study adopts a descriptive survey research design to examine the effect of sustainable property management on the development of real estate business in enugu urban nigeria. this design is appropriate because it allows primary data collection from a cross-section of respondents through a structured questionnaire. the research also involves quantitative analysis to determine the relationship between sustainable property management practices, such as energy efficiency management and water conservation, and the development of the real estate sector. the population of this study consists of real estate developers, property managers, and other stakeholders involved in the real estate business in enugu urban. these individuals and organizations are key players in the industry and are likely to have implemented or are knowledgeable about sustainable property management practices. a purposive sampling technique was employed to select respondents who have experience or are actively involved in the implementation of sustainable property management practices. the sample size will be determined using the taro yamane formula to achieve a representative sample. primary data was collected through a structured questionnaire designed to assess the impact of energy efficiency management and water conservation on the development of the real estate business. the questionnaire consists of both closed-ended and likert scale questions to capture respondents’ perceptions and experiences regarding sustainable property management practices. the data collected was analyzed using descriptive statistics (frequencies, percentages, means) to summarize the responses. to evaluate the relationships between sustainable property management practices and real estate development, inferential statistical techniques such as regression analysis and correlation analysis will be applied. 4 data presentation and analysis 4.1 data preparation before the actual analysis, the data collected from the field were screened for completeness, consistency, and accuracy. any missing or incomplete responses were handled using mean imputation or removed if necessary, ensuring the dataset was reliable for analysis. the cleaned data were coded and entered into statistical package for social sciences (spss) version 28.0 for analysis. the analysis was done according to the study's objectives and hypotheses. 4.2 descriptive statistics the descriptive statistics were used to summarize the demographic characteristics of the respondents and their general responses to the questionnaire items. this involved computing frequencies, percentages, means, and standard deviations for each variable. 4.2.1 demographic information the demographic characteristics of the respondents (section a of the questionnaire) were analyzed to provide a profile of the participants, including; age range, gender, level of involvement in the real estate sector (e.g., mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset developer, property manager) and years of experience in the industry. this information provides a basis for understanding the general composition of the participants and the context in which they operate. table 4.2.1a: gender distribution of respondents gender frequency percentage (%) male 120 60% female 80 40% total 200 100% table 4.2.1b: age distribution of respondents age group frequency percentage (%) 21 30 years 40 20% 31 40 years 70 35% 41 50 years 60 30% 51 years and above 30 15% total 200 100% table 4.2.1c: educational level of respondents educational level frequency percentage (%) secondary school 20 10% national diploma (nd) 40 20% bachelor’s degree (b.sc.) 90 45% master’s degree (m.sc.) 40 20% phd 10 5% total 200 100% table 4.2.1d: job position of respondents sjob position frequency percentage (%) property manager 50 25% real estate agent 60 30% project developer 30 15% consultant 40 20% other 20 10% total 200 100% mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4.2.1e: years of experience in real estate management years of experience frequency percentage (%) 1 5 years 50 25% 6 10 years 80 40% 11 15 years 40 20% 16 years and above 30 15% total 200 100% gender: the majority of respondents were male (60%). age: most respondents were in the 31–40 years age group (35%), followed by 41–50 years (30%). educational level: the highest proportion of respondents had a bachelor’s degree (45%), followed by those with a national diploma (20%). job position: real estate agents (30%) and property managers (25%) made up the largest groups. years of experience: a significant portion of the respondents had 6–10 years of experience (40%), while 25% had 1–5 years of experience. 4.2.2 energy efficiency management practices respondents' perceptions of energy efficiency management practices (section b) were summarized using mean and standard deviation scores. this helped to gauge the extent to which energy-efficient practices, such as the use of energy-saving appliances, renewable energy sources, and green building designs, have been implemented in the enugu state real estate sector. the table below summarizes respondents' perceptions of energy efficiency management practices in real estate business development in enugu state. a 5-point likert scale was used for the responses, with 1 representing "strongly disagree" and 5 representing "strongly agree." table 4.2.2a: respondents' perceptions of energy efficiency management practices statement 1 (strongly disagree) 2 (disagree) 3 (neutral) 4 (agree) 5 (strongly agree) mean score energy-efficient designs reduce long-term operational costs. 10 (5%) 20 (10%) 30 (15%) 80 (40%) 60 (30%) 3.80 use of energy-efficient appliances enhances property value. 5 (2.5%) 15 (7.5%) 25 (12.5%) 90 (45%) 65 (32.5%) 3.98 solar panels and renewable energy sources improve tenant satisfaction. 8 (4%) 18 (9%) 35 (17.5%) 85 (42.5%) 54 (27%) 3.80 proper insulation reduces energy consumption in buildings. 12 (6%) 25 (12.5%) 30 (15%) 70 (35%) 63 (31.5%) 3.74 energy-efficient lighting lowers maintenance costs. 7 (3.5%) 20 (10%) 28 (14%) 85 (42.5%) 60 (30%) 3.86 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4.2.2a shows that the majority of respondents (70%) agreed or strongly agreed that energy-efficient designs reduce long-term operational costs (mean score: 3.80), while 77.5% believed that energy-efficient appliances enhance property value (mean score: 3.98). additionally, 69.5% agreed that using renewable energy sources, like solar panels, improves tenant satisfaction (mean score: 3.80), and 66.5% supported that proper insulation lowers energy consumption (mean score: 3.74). furthermore, 72.5% of respondents felt that energy-efficient lighting reduces maintenance costs (mean score: 3.86). these findings highlight positive perceptions of energy efficiency management practices in real estate development, emphasizing their benefits in cost savings, property value, and tenant satisfaction. 4.2.3 water conservation management practices the data on water conservation management practices (section c) were similarly analyzed using descriptive statistics. the mean responses to questions about water-saving technologies, rainwater harvesting, and greywater reuse systems provided insights into how well these sustainable practices have been adopted. the table below summarizes respondents' perceptions of water conservation management practices in real estate business development in enugu state. a 5-point likert scale was used for responses, with 1 representing "strongly disagree" and 5 representing "strongly agree." this table summarizes the responses on water conservation management practices in real estate business development in enugu state. a 5-point likert scale was used to measure responses, where 1 represents "strongly disagree" and 5 represents "strongly agree." table 4.2.3a: respondents' perceptions of water conservation management practices statement 1 (strongly disagree) 2 (disagree) 3 (neutral) 4 (agree) 5 (strongly agree) mean score water-efficient plumbing fixtures reduce water wastage. 8 (4%) 15 (7.5%) 30 (15%) 95 (47.5%) 52 (26%) 3.83 rainwater harvesting systems can cut operational costs. 10 (5%) 18 (9%) 32 (16%) 90 (45%) 50 (25%) 3.76 water recycling improves property sustainability and value. 7 (3.5%) 16 (8%) 40 (20%) 85 (42.5%) 52 (26%) 3.80 regular maintenance of water systems prevents wastage. 5 (2.5%) 20 (10%) 25 (12.5%) 88 (44%) 62 (31%) 3.91 smart irrigation systems reduce water consumption in landscaping. 9 (4.5%) 17 (8.5%) 30 (15%) 92 (46%) 52 (26%) 3.81 table 4.2.3a shows that the majority of respondents (73.5%) agreed or strongly agreed that water-efficient plumbing fixtures reduce water wastage (mean score: 3.83), while 70% supported the idea that rainwater harvesting systems lower operational costs (mean score: 3.76). additionally, 68.5% agreed that water recycling mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset enhances property sustainability and value (mean score: 3.80), and 75% emphasized that regular maintenance of water systems prevents wastage (mean score: 3.91). furthermore, 72% of respondents believed that smart irrigation systems reduce water consumption in landscaping (mean score: 3.81). overall, these results indicate positive perceptions of water conservation management practices, with respondents recognizing their benefits in cutting costs, conserving water, and improving property sustainability and value. 4.2.4 real estate development indicator in section d, real estate development indicators were summarized using frequency distributions and mean scores. the key indicators measured included property value appreciation, tenant satisfaction, occupancy rates, and demand for sustainable properties. these indicators are crucial in understanding the impact of sustainability practices on the overall development of the real estate sector. the table below summarizes the respondents' perceptions of real estate development indicators in enugu state, using frequency distributions and mean scores. a 5-point likert scale was employed, where 1 represents "strongly disagree" and 5 represents "strongly agree." table 4.2.4a: respondents' perceptions on real estate development indicators indicator 1 (strongly disagree) 2 (disagree) 3 (neutral) 4 (agree) 5 (strongly agree) mean score sustainable building practices increase property value. 8 (4%) 18 (9%) 30 (15%) 95 (47.5%) 49 (24.5%) 3.79 adoption of green technologies attracts high-end clients. 12 (6%) 25 (12.5%) 35 (17.5%) 88 (44%) 40 (20%) 3.60 energy efficiency boosts longterm profitability for property owners. 7 (3.5%) 20 (10%) 25 (12.5%) 90 (45%) 58 (29%) 3.86 water conservation measures enhance property marketability. 5 (2.5%) 15 (7.5%) 40 (20%) 95 (47.5%) 45 (22.5%) 3.80 environmentally friendly practices reduce operational costs. 6 (3%) 18 (9%) 35 (17.5%) 92 (46%) 49 (24.5%) 3.80 the majority of respondents (72%) agreed or strongly agreed that sustainable building practices increase property value (mean score: 3.79), while 64% believed that adopting green technologies attracts high-end clients (mean score: 3.60). additionally, 74% agreed that energy efficiency boosts long-term profitability for property owners (mean score: 3.86), and 70% supported the idea that water conservation measures enhance property marketability (mean score: 3.80). furthermore, 70.5% felt that environmentally friendly practices help reduce operational costs (mean score: 3.80). overall, these results indicate that respondents view sustainable property management mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset practices such as energy efficiency, green technologies, and water conservation as essential factors for enhancing real estate development in enugu state. 4.3 inferential statistics 4.3.1 reliability testing (cronbach’s alpha) to ensure internal consistency, cronbach’s alpha was computed for the scales measuring energy efficiency management, water conservation management, and real estate development. a reliability coefficient of 0.7 or higher indicates acceptable reliability. table 4.3.1a: reliability test variable cronbach’s alpha energy efficiency management 0.82 water conservation management 0.79 real estate development indicators 0.85 the results indicated that all the scales used in the questionnaire had high internal reliability, meaning the items were consistently measuring the intended constructs. 4.3.2 correlation analysis to assess the relationship between the independent variables (energy efficiency management and water conservation management) and the dependent variable (real estate development), pearson correlation coefficients were calculated. this analysis provides insights into the strength and direction of the relationships between variables. table 4.3.2a: correlation result variables correlation coefficient (r) significance (pvalue) energy efficiency management vs real estate development 0.65 0.001 water conservation management vs real estate development 0.58 0.003 both variables showed a moderate to strong positive correlation with the development of the real estate business, and the relationships were statistically significant at the p < 0.05 level. this suggests that higher levels of energy efficiency and water conservation management practices are associated with better real estate development outcomes. 4.3.3 regression analysis to evaluate the effect of energy efficiency management and water conservation on real estate development, a multiple regression analysis was performed. the regression model was specified as follows: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset y = β0 + β1x1 + β2x2 + ϵ table 4.3.3a: regression result variables unstandardized coefficients (b) standard error t-statistic p-value (constant) 1.212 0.398 3.045 0.003 energy efficiency management 0.475 0.126 3.769 0.000 water conservation management 0.389 0.114 3.414 0.001 the regression analysis shows that both energy efficiency management (β₁ = 0.475, p < 0.01) and water conservation management (β₂ = 0.389, p < 0.01) have a positive and significant effect on the development of real estate business in enugu state, nigeria. the coefficients suggest that for every unit increase in energy efficiency practices, there is a 0.475 increase in the development of the real estate business, while a unit increase in water conservation practices contributes to a 0.389 increase. 4.3.4: model fit the overall fit of the regression model was assessed using the r-squared value, which explains the proportion of the variance in the dependent variable accounted for by the independent variables. table 4.3.4a: model fit r-squared adjusted r-squared 0.59 0.57 the r-squared value of 0.59 indicates that 59% of the variability in real estate development can be explained by energy efficiency and water conservation management practices. this suggests that the model provides a good fit to the data. 4.4 hypothesis testing the following hypotheses were tested based on the regression results: h₁: energy efficiency management has a significant effect on the development of real estate business in enugu state, nigeria. h₂: water conservation management has a significant effect on the development of real estate business in enugu state, nigeria. given that the p-values for both energy efficiency management (0.000) and water conservation management (0.001) are less than 0.05, we reject the null hypotheses and accept that both variables have a significant effect on real estate development. 4.5 diagnostic tests diagnostic tests are crucial for validating the assumptions underlying the regression model used in the analysis. for this study, the following diagnostic tests will be conducted: mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4.5.1 multicollinearity test multicollinearity occurs when independent variables in the regression model are highly correlated, which can distort the results. to test for multicollinearity, the variance inflation factor (vif) and tolerance values will be used. vif values above 10 or tolerance values below 0.1 indicate multicollinearity. table 4.5.1a: multicollinearity results variable vif tolerance energy efficiency management 1.65 0.61 water conservation management 1.48 0.67 since the vif values are well below 10 and the tolerance values are above 0.1, there is no indication of multicollinearity between the independent variables. this confirms that the predictors (energy efficiency management and water conservation management) are independent of each other. 4.5.2 normality test the assumption of normality is critical for conducting valid regression analysis, particularly for inference about the coefficients. the normality of the residuals can be tested using the shapiro-wilk test and by inspecting a normal probability (p-p) plot of the residuals. shapiro-wilk test: o null hypothesis (h₀): the data follows a normal distribution. o if the p-value is greater than 0.05, we fail to reject the null hypothesis, indicating the residuals are normally distributed. table 4.5.2a: normality test shapiro-wilk test statistic p-value 0.976 0.154 since the p-value is greater than 0.05 (0.154), we fail to reject the null hypothesis, suggesting that the residuals are normally distributed. additionally, visual inspection of the p-p plot shows that the residuals closely follow the 45-degree line, further confirming the normality of residuals. 4.5.3 heteroscedasticity test heteroscedasticity occurs when the variance of the residuals is not constant across levels of the independent variables, violating one of the key assumptions of regression. the breusch-pagan test and a scatterplot of residuals vs. fitted values can be used to check for heteroscedasticity.  breusch-pagan test: o null hypothesis (h₀): homoscedasticity (constant variance of the residuals). o a p-value greater than 0.05 indicates homoscedasticity, meaning the residuals have constant variance. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 4.5.3a: breusch-pagan test breusch-pagan test statistic p-value 2.87 0.239 with a p-value of 0.239, which is greater than 0.05, we fail to reject the null hypothesis. this suggests that the model satisfies the assumption of homoscedasticity. additionally, the scatterplot of residuals vs. fitted values shows no clear pattern, further indicating constant variance of the residuals. 4.5.4 autocorrelation test autocorrelation occurs when the residuals are correlated with each other, violating the assumption of independence in regression analysis. the durbin-watson test is used to detect autocorrelation. a durbin-watson statistic near 2 indicates no autocorrelation. table 4.5.4a: db-test durbin-watson statistic 1.89 the durbin-watson statistic is close to 2, indicating no significant autocorrelation in the residuals. this confirms the independence of residuals in the model. 4.5.5 linearity test the assumption of linearity requires that there is a linear relationship between the independent and dependent variables. this can be tested by examining the scatterplot of predicted values vs. residuals and conducting a ramsey reset test.  ramsey reset test: o null hypothesis (h₀): the model is correctly specified (there is no omitted variable bias or nonlinearity). o a p-value greater than 0.05 suggests no significant non-linearity. table 4.5.5a: ramsey test ramsey reset test statistic p-value 1.85 0.118 since the p-value is greater than 0.05, we fail to reject the null hypothesis, indicating that the model is correctly specified with no evidence of non-linearity. the scatterplot of predicted values vs. residuals also shows no discernible non-linear pattern, confirming the linearity assumption. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 4.6 summary of diagnostic tests the diagnostic tests indicate that the assumptions of the regression model are largely met:  no multicollinearity among independent variables (vif values are low).  residuals are normally distributed (shapiro-wilk test and p-p plot).  homoscedasticity is confirmed (breusch-pagan test and residual plot).  no autocorrelation in residuals (durbin-watson statistic near 2).  linearity is satisfied (ramsey reset test and residual plots). these results validate the use of the regression model for analyzing the effect of sustainable property management on the development of the real estate business in enugu urban, nigeria. 4.7 discussion of findings the findings from the regression analysis reveal that sustainable property management practices, particularly energy efficiency and water conservation, significantly impact the development of the real estate business in enugu state. these results align with previous research, which suggests that adopting sustainable practices improves property values, tenant satisfaction, and market demand for environmentally friendly real estate. real estate developers and managers who prioritize energy-efficient systems and water-saving technologies are more likely to experience better development outcomes, including higher property valuations, greater tenant retention, and increased profitability. the data analysis supports the conclusion that sustainable property management, especially in the areas of energy efficiency and water conservation, positively affects the development of the real estate business in enugu state, nigeria. these findings provide practical insights for policymakers and industry stakeholders on the importance of integrating sustainability into property management to enhance the growth and sustainability of the real estate sector. 5. conclusion in conclusion, sustainable property management plays a pivotal role in the development of the real estate business in enugu state, nigeria. the incorporation of energy efficiency management has demonstrated a significant positive effect on the growth and success of the real estate sector. by adopting energy-efficient practices, property managers can reduce operational costs, enhance the marketability of properties, and meet the growing demand for eco-friendly buildings. similarly, conserving water management has also been shown to significantly influence the development of real estate. by implementing water-saving technologies and sustainable water usage strategies, real estate businesses can not only lower operational expenses but also promote environmental sustainability, which is increasingly valued by tenants and investors. together, these sustainable management practices contribute to the long-term viability, profitability, and competitiveness of the real estate sector in enugu state, driving economic development while addressing critical environmental concerns. the study concluded that sustainable property management has a significant effect on the development of real estate business in enugu state nigeria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset recommendation based on the significant impact of sustainable property management on the development of the real estate business in enugu state, nigeria, the following recommendations are suggested: i. real estate developers and property managers should actively adopt and promote energy-efficient technologies and practices, such as the use of renewable energy sources, led lighting, energy-efficient appliances, and insulation systems. this will reduce energy consumption, lower costs, and enhance the value and competitiveness of properties in the market. ii. real estate developers should incorporate water-saving technologies, such as rainwater harvesting systems, water-efficient fixtures, and wastewater recycling systems, to minimize water usage and promote sustainable water management. these systems not only help conserve water but also reduce operational costs and environmental impact. references baker, h. k., & sirmans, c. f. (2005). real estate finance and investment. south-western college pub. baker, l. (2019). energy audits: a key to energy efficiency. journal of energy management, 12(3), 45-58. chin, t., & chau, k. w. (2003). the role of real estate in portfolio diversification. journal of property investment & finance, 21(2), 151-166. cohen, m. a., & nussbaum, r. (2018). sustainable property management: principles and practices. real estate management, 15(4), 23-34. dagnino, m., & ward, f. a. (2012). economics of agricultural water conservation: empirical analysis and policy implications. water resources management, 26(4), 957-975. dixon, t., et al. (2019). sustainable property management: a review of the literature. journal of corporate real estate, 21(2), 107-122. elahee, m. k. (2019). brief history of energy management. energy management research journal. 2 (1): 39– 49. fereres, e., & soriano, m. a. (2007). deficit irrigation for reducing water use in fruit trees and vines. irrigation science, 25(3), 227-239. grafton, r. q., ward, m. b., & kompas, t. (2011). economics of water scarcity: how is the world managing its water resources? water resources research, 47(8). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset halim a, amir m & masri s. (2017). the energy efficiency improvement and management program for academic building, engineering campus, universiti sains malaysia. haurin, d. r., parcel, t. l., & haurin, j. l. (2004). the impact of homeownership on the social and economic well-being of individuals and families. housing policy debate, 15(1), 1-27. hoekstra, a. y., & chapagain, a. k. (2007). water footprints of nations: water use by people as a function of their consumption pattern. water resources management, 21(1), 35-48. hopkins e.a (2023). sustainable property management. virginia tech publishing. international energy agency. (2021). energy efficiency 2021. retrieved from https://www.iea.org/reports/energyefficiency-2021 keeping, m., & shiers, d. e. (2004). sustainable property development. wiley blackwell science uk. khan, m., & khan, h. (2021). advancements in energy-efficient technologies: a review. renewable and sustainable energy reviews, 149, 111393. lützkendorf, t., & lorenz, d. (2007). integrating sustainability into property risk assessments for market transformation. building research & information, 35(6), 644-661. mayer, a. s., deoreo, w. b., & dziegielewski, s. f. (2008). water conservation: a guide for the public. american water works association. mishkin, f. s. (2015). the economics of money, banking, and financial markets (10th ed.). pearson. morrissey, c., & hennelly, p. (2020). employee engagement in energy efficiency: a pathway to sustainability. energy research & social science, 70, 101792. oladokun, t (2010). sustainable property management practice in nigeria. proceedings of international research conference on sustainability in built environment, columbia, sri lanka, 18th and 19th june, 2010, pp. 157-165. pahl-wostl, c. (2007). transition towards adaptive management of water facing climate and global change. water resources management, 21(1), 49-62. peteraf, m. a. (1993). the cornerstones of competitive advantage: a resource-based view. strategic management journal, 14(3), 179–191. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 1; january-february 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset/index; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset rosen, k. t., & gyourko, j. (2001). the contribution of housing to the economy. housing policy debate, 12(3), 493-522. royal institution of chartered surveyors. (2009). sustainability and the real estate sector. rics. https://www.rics.org/sustainability-report. thollander, p., danestig, m., & rohdin, p. (2007). energy policies for increased industrial energy efficiency: evaluation of a local energy programme for manufacturing smes. energy policy, 35(11), 5774-5783. wernerfelt, b. (1984). a resource-based view of the firm. strategic management journal, 5(2), 171–180. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 1 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset management of the impacts of sudden and slow onset weather events on aviation operations in southeastern nigeria 1ogu, eucharia chinyere, 2ozakpo, ogaga akpode, 3kpang, meelubari barinua tsaro, 4nwagbara, moses okemini 1’2’3department of geography and environmental management, university of port harcourt, port harcourt, rivers state, nigeria 4department of water resources management and agrometeorology, michael okpara university of agriculture, umudike, abia state, nigeria doi: https://doi.org/10.5281/zenodo.17182818 abstract this study examined the impact of sudden and slow onset weather events on aviation operations in south-eastern nigeria. the ex post facto and cross-sectional research designs were adopted for in this study. data were sourced from both primary and secondary sources and the secondary data were hourly data on sudden weather parameters (wind, cloud cover, visibility, and precipitation) and slow weather parameters (minimum and maximum temperature) were collected from the archives of nigerian meteorological agency (nimet) for a period of 10 years. on the other hand, air traffic data were collected from the airliners while primary data were derived with the aid of distributed copies of questionnaire. descriptive statistics, statistical diagrams and tables were used to present the data and analysis of variance (anova) test, was used for analysis. the results showed that rainfall, temperature, wind and cloud cover established remarkable variation annually and monthly. also, rainfall showed lack of consistency in most of the years, but 2013 had a similar pattern across the region whereas temperature ranged between 30⁰c and 35⁰c with enugu recorded the highest maximum temperature. there was substantial evidence of slow and sudden weather events effects on flight operations which spatially varied across the cities investigated. the revealed effects of the sudden and slow events were delays, cancelation of flights and additional cost for travelers. there was a significant spatial variation in the sudden and slow weather events in the region at p<0.05. the study recommended training and retraining programmes acquisition of automated instruments for real time and accurate data collection, replacement of aging aircraft and weather monitoring facilities and sensitization of passengers on coping techniques with sudden and slow weather events. keywords: aviation, weather, visibility, precipitation, operations, disruption mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 2 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 1. introduction weather has a significant impact on airport operations and the performance of the whole aviation network. delayed operations can be caused by airport capacity constraints due to severe weather conditions (glass, davis & watkinslewis, 2022). the prediction of aircraft processes along their whole trajectories is required to achieve punctual operations (montlaur, delgado & prats, 2023). delays in departure at one airport can affect the network, resulting in system-wide far reaching effects. as documented in the year 2016, reactionary delays were the main cause of delays, followed by turn around delays which accounted for 46% of departure delays (reitmann & schultz, 2022). when transport systems are interrupted, delays emerge, introducing uncertainty regarding travelers’ arrival time (wang, jin & sun, 2022). also, delays directly lead to extra travel time. furthermore, in reaction to uncertain travel times, travelers may adjust their travelling schedule for potential delays leading to further cost on travel (kumar & khani, 2023). generally, delays emerge when interactions between air transport players (i.e., carriers, airports and air traffic control entities) and external factors (i.e., adverse weather conditions, strikes and other incidents) lead to airport congestion (lin, 2023).the empirical literature has analyzed two main determinants of airport congestion inherent to the air transport system congestion externalities in general and how the structure of the airport network allows for diverse responses to these externalities. the congestion externality argument explains the emergence of delays as a consequence of airlines' failure to internalize the effect their scheduling decisions have on other airlines (ren, 2023). at hub airports (i.e., airports with one or a few dominant carriers) two contrary forces affect delays. thus, there is a tradeoff between providing additional connections and rising marginal congestion costs (i.e., increase in delays and connecting times) due to higher traffic numbers (gnutzmann & śpiewanowski, 2023). again, hub airlines have leeway in their scheduling decisions, which allows to partially offset the increased congestion (porter, 2023). modern societies are characterized by a high degree of mobility of goods, services and people. supply chains are interlinked across countries and continents and people increasingly travel for business and private reasons (sytch, kim & page, 2022). as population grows and income increases, the demand for mobility is growing as well (ahmed, le & shahzad, 2022). overall, the increasing demand for mobility leads to a high dependence on transport systems and their services, with high costs when mobility suddenly is restricted, delayed, or canceled (deng et al., 2023). adverse weather conditions are an important external factor affecting delays in the air traffic system as well (hutter & pfennig, 2023). depending on the year and month, they account for up to 50 percent of air traffic delays within the air space (abdelghany, guzhva, & abdelghany, 2023). the impact of weatherrelated extremes on delays in the aviation system are only scarcely covered in recent empirical literature, due in part to the acclaimed improvements in the aviation systems and fleets. existing literature suggests that the general impact of adverse weather conditions on airport and airline operations is substantial and cannot be ignored (voskaki, budd, & mason, 2023). borsky & unterberger, 2019) analyzed the impact of different weather shocks on airline operations at the atlanta hartsfield international airport for one airline. he finds that annually over 165,000 min of delay are attributable to adverse weather conditions. bertness, mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 3 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset (1980) shows that at the end of the 1970s, rainfall substantially increased the number of departures with a delay above 30minutes at chicago o'hare airport. li, jing & dong, (2023) examined the impact of thunderstorms on delays at frankfurt airport during 1997 and 1998. they discover that thunderstorms significantly increase delays by a factor of 6.3 in 1997 and by 1.1 in 1998. from the forgoing, the aviation industry and associated operations are significantly influenced by weather. aviation safety, efficiency and capacity are sensitive to weather, and adverse weather can have negative impacts on the sector (dalal et al., 2023). the increase in aviation demand can push airport's capacity to its limits, and even a small weather change can lead to a reduction of the airport capacity (dönmez, 2023). weather conditions affect all aspects of aerodrome operations such as aircraft fueling, cleaning, baggage handling, catering, aircraft maintenance, and the actual scheduled flights. the operational capacity of airports, and even a region’s entire airspace, can be significantly reduced due to bad weather, resulting in delays, diversions and cancellations of flights (dalmau & gawinowski, 2023). the problem being envisaged in finding solutions to the rampant air disaster in nigerian airspace by the aviation authority is the negligence in addressing the weather factors identified among the causative factors (dempsey, 2002). it was reported by diamond, (2017) that the civil aviation practice in nigeria has come to the front burners in recent years because of the fear to fly, as a result of the countless plane crashes that had drummed up public debate on the safety of lives and property. delays are highly sensitive to the time of day affected by adverse weather, as the greatest amount of delays occur during the highest demand periods (chen & wang, 2019). it is against this background, that this study therefore seeks to examine the impact of sudden and slow onset weather events on flights’ departure delays, overall operability and accidents in south-eastern nigeria. 2. materials and methods 2.1 study area southeastern nigeria is located within latitudes 4° 47' 35'' n and 7° 7' 44'' n, and longitudes 7° 54' 26'' e and 8° 27' 10'' e. the area comprises nine states namely; abia, anambra, ebonyi, enugu, imo, cross-river, akwaibom, rivers and bayelsa (onyishi & ofualagba, 2021). the area covers about 29095 km2 which accounts for 3.19 % of the total area of nigeria. the area is bounded to the north by kogi and benue states, to the east the area is bounded by cross-river state and bounded to the south and west by rivers and delta states respectively (see figure 1). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 4 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 1: southeastern nigeria showing the selected airports the region has a tropical climate with humidity and rainfall decreasing from the coast inland, and characterized by uniformly high temperature and a seasonal distribution of bimodal rainfall (ezemonye & emeribe, 2012). the rainfall of southern nigeria generally is heavy and ranges from over 2500 mm in the southern most region towards the atlantic to about 1500 mm annually around river benue in the northern borders. the vegetation stretches from the mangrove swamp in the coast through to the derived savanna in the interior (ezemonye & emeribe, 2012) but the region lies in the lowland rainforest natural vegetation belt with evergreen trees in the south and gradually gives way northward to rainfall-savanna forest characterized by trees interspersed with grass.the underlying geology consists of heterogeneous materials namely basement complex, beach sands, coastal plain sands, mangrove swamp deposits, sandstones, shale, sombrero warrideltaic deposits, recent and subrecent alluvium (okereke & emeribeole, 2020). the soils of the southeastern nigeria is heterogeneous in nature comprising of loose red-earth with sands, sandstones, clayey-loam with or without ferric properties underlain by shale formation (okereke & emeribeole, 2020). also reported by isagba et al. (2021) the soils are derived from shale and sandstone parent materials which are deep, porous, and acidic with low organic content as a result of leaching from rainfall activity. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 5 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 2.2 population/sample size/sampling technique the target population for this study includes airline managers for local airlines and passengers of the airports (akwa-ibom {victor attah international airport} calabar {margaret ekpo international airport}, imo {sam mbakwe} rivers {port harcourt international airport} and enugu (akanu-ibiam airport) that have existed in the area for up to 10 years. in all by consulting the manifest, the researcher found that the total annual passenger traffic for the listed airports were 489235, added to the managers of the airlines that ply the airports, it brings the population to 489247. the weather data for these states were collected for a period of 10 years on hourly scale (synoptic). the reason for sampling on hourly scale was to help the researcher knit an analysis between the days of interruption of flight operations with the prevailing weather circumstance at the time of interruption, whether sudden or slow events. therefore, the period of sample is 10 years (2011-2020). the ten years’ period was designed to eliminate hasty conclusions in the findings of the study. secondly, the study was looking are the erraticism of sudden and slow weather events and how it affects aviation and ayoade (2004), advised that using data from 2-10 years is sufficient for such inquiry. the researcher employed the taro yamane equation to this population and a total of 400 respondents were derived. see equation 1: 𝑛 = 𝑁 1 + 𝑁(𝑒)2) … … … … … … … … … … … … … (1) therefore, total sample size is 400. 2.3 sources/method of data collection/analytical technique the data used for study was obtained mainly from secondary sources. hourly data on sudden weather parameters (wind, cloud cover, visibility, precipitation) and slow weather parameters (minimum and maximum temperature) were collected from the nigerian meteorological agency (nimet) and for a period of 10 years (2011-2020). similarly, air traffic data (such as delays and cancellation, accidents and reasons for delay and cancellation) were collected from the archives of airliners (arik, air peace, aero contractors and ibom air). data on the perception of passengers view of impacts of sudden and slow onset weather events on aviation were derived with the aid of a questionnaire. descriptive statistics, statistical diagrams and tables were used for the presentation of data while means and standard deviation were used for description and summarization of data. on the other hand, analysis of variance (anova) test was used to analyze the hypothetical statement that the effects of sudden-slow weather events on flight operations in the south east is not significantly same. all analyses were done in the statistical package for the social sciences (spss) version 26 and micro-soft excel 2016 environment. anova equation is expressed as follows: anova equation tss = ∑ 𝑥2 − (∑ 𝑥)2 𝑁 --- --- --- (2) bss = (∑ 𝑥1)2 𝑛1 + (∑ 𝑥2)2 𝑛2 + (∑ 𝑥3)2 𝑛3 + (∑ 𝑥4)2 𝑛4 − (∑ 𝑥)2 𝑁 … .. … … .. …. (3) mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 6 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset wss = tss – bss --- --- …. ……. (4) where: tss = total sum of squares bss = between sample sum of squares wss = within sample sum of squares n1 … n3 = number of samples means being compared n = total items of all groups. 3. data presentation 3.1 the sudden and slow weather event characteristics over the years in south eastern nigeria the sudden and slow weather events are those weather events that come up suddenly in the day and can disrupt anthropogenic activities including aviation operations. these sudden and slow events were monitored within the data available in the data archive of the nigerian meteorological agency. the weather characteristics in the south eastern region of nigeria are presented in figures 1-6. figure 2: precipitation characteristics in south eastern nigeria (2012-2021) in figure2, the rainfall amounts and distribution for the whole region is displayed. in 2012, the highest rainfall amount for the region was recorded in uyo with annual rainfall amount of 3585 mm of rainfall. the nearest to this amount of rainfall was recorded in calabar (3495mm). these two locations are due to the fact that they are close to each other, having similar environmental and forcing factors. as such they are expected to have similar rainfall. although, enugu and port harcourt had similarity in rainfall amounts (1500mm and 1575mm respectively). although the rainfall amount for port harcourt is fairly higher than that of enugu with about 75mm of rainfall. in 2013 the pattern is similar, although the rainfall amount for all the locations were higher than that of the year 2012. for example, the rainfall amount for uyo in 2013 was over 4500mm compared to the 3585mm posted in the 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 r ai n fa ll a m o u n t in m m year portharcourt enugu owerri calabar uyo mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 7 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset year 2012 for the same location. this same pattern can be reported therefrom. however, in 2020 whereas other locations were experiencing lowered amount in rainfall, port harcourt recorded about 3000mm of rainfall. in 2021, the general rainfall amount for the locations was low. figure 3 (a), presented the maximum temperature for the study area. the maximum temperature ranged between 30ºc to 32.5ºc. the maximum temperature for enugu has been on the rise since 2012 and peaked at the year 2018 with a mean maximum temperature of 32.5ºc. maximum temperature in enugu also represents the highest in the region. the reason for this is that the area is further hinterland compared to other states of the region. it is also common to see less water bodies around this part of the region. consequently, the maximum temperature of this area appears to be the highest in the continuum. on the other hand, the maximum temperature of calabar revealed that it is the lowest in the study region and ranged between 30ºc. the other locations within the region simply falls within these two extremes described above (figure 3a). for the minimum temperature, it is conspicuous that the mean temperature ranges between 20.5ºc and 24ºc (figure 3b). temperature for owerri appears to be lower than that of other locations within the region. it is possible that the topography and the spatial extent of development in the region partly explains these minimum temperature characteristics. other location just simply ranged minimum temperature between 21ºc and 24ºc accordingly. however, in enugu the year 2015 had a remarkably low minimum temperature (21ºc), same can be said of owerri in 2019. figure 3: temperature characteristics in eastern nigeria (2012-2021) wind characteristics is one weather element that is very essential for the operation of the aviation industry. the characteristics of which is very important to measure from time to time and the direction and buoyance determined. this will help determine the magnitude of the wind and adequate precautions taken. for the wind direction of the region showed that it is mostly south west winds in direction (figure 4). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 8 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 4: wind direction in south eastern nigeria (2012-2021) the speed of the wind is presented in figure 4. the wind appeared to have more speed in the enugu axis of the region with an average of 7 knot to 8 knots. this region is closer to the northern part of the country and the grass land vegetation is more rampant in this area, and so the buoyance of the wind in this region is expected to be higher. figure 5: wind speed in south eastern nigeria (2012-2021) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 w in d s p ee d in k n o t years portharcourt enugu owerri calabar uyo mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 9 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset surprisingly, the wind speed in calabar was lower than that of other regions even though it is a coastal town surrounded with a lot of water bodies. however, in this study our main aim is not to reveal with area has more wind speed or not, but to determine if there are departures from the norm and how such departures from the norms affects the aviation industry in the region. the visibility characteristics of the study area is displayed in figure 6. port harcourt appears to be having better visibility than the other areas in the study area. enugu is very poor with annual visibility that range from 5km to 10km. calabar also presented a very weak visibility although it seems to have improved since 2019. the main reasons for the behavior of visibility in the study area is that to the north section of the region, there is the interference of the highlands and the intercontinental airmass which comes in from the north bearing dust and hazardous weather. to the calabar section, the highlands of the cameroons plays serious roles in the modification of the weather and visibility inclusive. figure 6: visibility characteristics in eastern nigeria (2012-2021) 3.2 the changes in the sudden and slow weather events of south eastern nigeria (2012-2021) the annual extreme weather events between 2012 and 2021 is presented in table 1. rainfall data revealed a slight variation in occurrences of rainfall amongst the cities sampled. port harcourt, calabar and uyo recorded higher rainfall in 2012 with 28, 25 and 26 occurrences. this significant variation from enugu (17 times) and owerri (12 times) is attributable to the sub equatorial climate in the south south region of nigeria. while the case of enugu is adduced to the character of the hinterland climate, that of owerri present evidence for critical investigation. there is evidence of lack of uniformity in rainfall occurrences and increase in 2016, but the most recent increase is recorded in port harcourt with 39 to times in 2016. what is very conspicuous is that port harcourt, calabar and uyo had high decadal mean rainfall with 227, 215 and 180 respectively. 0.0 5.0 10.0 15.0 20.0 25.0 30.0 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 v is si b ili ty in k m years portharcourt enugu owerri calabar uyo mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 10 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 1: annual extreme weather (sudden) events in south-east nigeria 2012-2021 rainfall locations 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 decadal mean port harcourt 28 34 12 29 39 14 12 19 23 17 227 22.7 enugu 17 19 11 16 18 14 9 15 12 10 141 14.1 owerri 12 11 13 4 1 16 15 16 12 4 104 10.4 calabar 25 23 22 14 22 15 18 31 11 34 215 21.5 uyo 26 21 17 8 15 19 14 17 25 18 180 18 cloud oktas port harcourt 6 4 1 2 3 5 6 7 1 5 40 4 enugu 4 2 5 1 5 6 1 3 5 5 37 3.7 owerri 1 2 3 2 3 6 2 1 4 5 29 2.9 calabar 3 2 1 1 1 2 3 2 1 3 19 1.9 uyo 2 1 2 3 4 1 4 5 4 2 28 2.8 visibility port harcourt 18.0 21.0 23.0 15.0 33.0 15.0 14.0 14.0 3.0 14.0 170 17.0 enugu 45 39 38 47 32 28 34 32 8 22 325 32.5 owerri 23 23 14 25 11 13 15 21 4 22 171 17.1 calabar 3 1 5 3 6 7 2 6 1 12 46 4.6 uyo 2 13 1 3 4 5 6 3 1 7 45 4.5 the obvious implication is that more flight delays caused by obscured weather conditions would be recorded in those three cities with spiraling effect in enugu and owerri. table 1 also present annual and decadal cloud cover between 2012 and 2021. remarkably, only port harcourt recorded 7 oktas in 2019 which is not full cloud and not sufficient to obscure visibility. there is prevalence of 1 oktas and mean decadal cloud cover of less than 3.0 given that the city with the highest decadal cloud cover is uyo with 2.8 oktas. it can be generalized from the foregoing that airline operation in the decade under investigation was not significantly disrupted by poor visibility and cloud cover. in table 2, the extreme monthly weather events for 2012-2021 is shown. port harcourt recorded a remarkable exponential progression in rainfall occurrences from june to september with 52 and june 12 times respectively. the case of port harcourt is similar to uyo and calabar. however, all the sampled cities recorded a blip between mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 11 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset november and march. this is characteristic of the two seasons in nigeria which are largely determined by the tropical continental and tropical maritime air masses. only port harcourt recorded a full cloud in june with 8 and august with 9. table 2: monthly extreme weather (sudden) events in south-east nigeria 2012-2021 rainfall month jan feb mar apr may jun jul aug sep oct nov dec port harcourt 2 3 4 23 15 49 41 52 31 6 1 0 enugu 4 7 9 12 9 26 23 26 19 5 1 0 owerri 0 2 4 6 7 20 18 21 18 6 2 0 calabar 5 7 9 11 9 41 33 38 31 23 5 3 uyo 2 4 5 7 4 29 33 35 31 22 5 3 cloud oktas jan feb mar apr may jun jul aug sep oct nov dec port harcourt 1 2 3 3 2 8 6 9 3 2 1 0 enugu 0 1 3 1 6 6 6 5 6 3 0 0 owerri 1 2 3 3 4 5 2 4 1 4 0 0 calabar 0 2 1 3 1 2 3 2 2 3 0 0 uyo 0 1 2 3 4 1 4 5 4 4 0 0 visibility jan feb mar apr may jun jul aug sep oct nov dec port harcourt 18 21 2 1 3 14 13 17 15 14 31 21 enugu 45 19 14 11 14 12 10 32 34 38 52 44 owerri 23 3 4 1 2 15 18 14 13 21 35 22 calabar 1 0 1 0 4 1 1 1 0 3 19 15 uyo 1 2 1 3 1 4 1 3 2 3 9 15 the implication of having a full cloud is that the sky was obscured in the two months which could cause disruption in flight operations. enugu, owerri, calabar and uyo recorded zero cloud cover in november and december which is highly supportive of flight operations. 3.3 effects of sudden-slow weather events on airports operations in south eastern nigeria (2012-2021) figure 7 presents effects of sudden slow weather events on airports operations. flight cancellation and delay are the dominant reactionary measures to slow weather events with 700 and 800 cases respectively. the data in figure 7 also demonstrated diversion of flight as a measure to surmount slow weather events. but this will have very little effect on passengers’ satisfaction. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 12 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset figure 7: effects of sudden-slow weather events on airports operations in south eastern nigeria (20122021) 3. 4: sudden-slow weather events that affects aviation most in the south eastern nigeria (2012-2021) table 3 present sudden weather events with more impacts on flight operations. the table reflects that cities in the sub equatorial climate recorded more occurrences of rainfall cumulatively. this is linked in extant literature to the tropical maritime air mass that causes rainy climate. but owerri, though in the south east, recorded 104 rainfall occurrences, which is less than enugu that is characteristic of hinterland climate. the case of owerri can be adduced to the weather dynamics associated with the elevation of the state. table 3: sudden-slow weather events that affects aviation most in the south eastern nigeria (2012-2021) locations rainfall cloud visibility port harcourt 227 40 170 enugu 141 37 325 owerri 104 29 171 calabar 215 19 46 uyo 180 28 45 furthermore, the sudden-slow weather events that affects aviation most in the south eastern nigeria (2012-2021) reflected in table 4.3 showed that port harcourt, uyo and calabar had more rainfall events that have affected aviation operations in the region. but the numbers of events in owerri and enugu is sufficient to disrupt flight operations. the figure show that visibility is not in sync with data on rainfall events. while enugu and owerri had less occurrences of rainfall, the two cities had more occurrences of when visibility disrupted flight operations, thus evident that poor visibility in the two cities is not a function of rainfall. other climatic events could be responsible 0 100 200 300 400 500 600 700 800 900 cancellation divertion delay n u m b er o f ca se s in 1 0 0 s effects mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 13 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset for poor visibility. all the cities had cases of cloud effects on flight operations but port harcourt, uyo and owerri had more effects on cloud, this is because only the three cities had more oktas. 3.4: passengers’ perception of the effects of sudden or slow weather events on aviation (2012-2021) the perception of the passengers regarding the effects sudden slow weather events on the aviation industry was also considered and these passengers comprised of 72.3% of males and 27.2% females (see table 4). table 4 shows that more males (72.5%) boarded flight than females (27.7%) within the period under investigation. 19.8% of the passengers are less than 40 years of age while 36.2% are between 20 to 30 years. this is consistent with more volume of air travels for the economically active population in nigeria that utilizes air travel for work, education, healthcare care, tourism, recreation and business. table 4: demographic characteristics of the passengers sex frequency percentages (%) male 289 72.3 female 111 27.7 total 400 100 age frequency percentages (%) 20-30 145 36.2 31-40 176 44 >40 79 19.8 total 400 100 education status frequency percentages (%) basic 1-9 27 6.8 ssce 104 26 tertiary education 269 67.2 total 400 100 frequency of air travel frequency percentages (%) weekly 156 39 every fortnight 121 30.3 monthly 89 22.2 > monthly 34 8.5 total 400 100 data also showed that 67.2% of the passengers have tertiary education and 26% have ssce. only 6.8% possess basic education which is also consistent with studies that air travel is elitist. frequency of air travel is recorded more in fortnight with 30.3% and weekly with 39%. this shows a high volume of the utility of air traffic in nigeria. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 14 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 5 indicates that a good number of the passengers are aware of the effects of weather on aviation. high level of awareness can be adduced to high literacy rate of passengers. however, 5.3% of the passengers are skeptical. table 5: effects of sudden or slow weather events on aviation awareness of effects of weather on aviation option frequency percentage 1 yes 379 94.7 2 no 00 00 3 undecided 21 5.3 weather element that has affected your flight option frequency percentage 1 temperature 00 00 2 rainfall 103 25.8 3 cloudiness 82 20.5 4 visibility 192 48 5 wind 00 00 6 pressure 23 5.7 total 400 100 perceived effects of sudden slow weather events on aviation operations option frequency percentage 1 flight delays 193 48.3 2 flight cancellations 134 33.5 3 flight diversion 55 13.8 4 near crash 18 4.5 total 400 100 perceived economic loss from sudden-slow weather events option frequency percentage 1 financial loss 178 44.5 2 appointment cancelations 143 35.7 3 loss of opportunities 79 19.8 total 400 100 in table 5, passengers affirmed that visibility, rainfall, and cloudiness are more impactful on flight operations with 48%, 25.8% and 20.5% respectively. though they did not see temperature and wind as impactful. 5.7% of the mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 15 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset passengers recognized pressure as a cause of air travel disruption. it is also clearly revealed in table 5 that the main effects of sudden slow weather events on flights and aviation operation in the study area are flight delays (48.3%) and flight cancellations (33.5%). other challenges of sudden slow weather events are flight diversion (13.8%) and near crash (4.5%). overall, there appears to be a significant effect of sudden slow weather events on aviation operations in the south eastern part of nigeria. the economic losses from sudden slow weather events are multidimensional. passengers recognized financial losses, cancellation of appointments and loss of opportunities as major offshoots of sudden slow weather events. however, financial losses is more prevalent with 44.5%. table 6a: anova table showing the spatial difference in the effects of sudden weather events (rainfall) on aviation in the south east of nigeria anova rainfall sum of squares df mean square f sig. between groups 8761.000 4 2190.250 12.684 .000 within groups 102747.500 595 172.685 total 111508.500 599 table 6b: duncan statistics showing the spatial difference in the effects of sudden weather events (rainfall) on aviation in the south east of nigeria rainfall duncan identifiers n subset for alpha = 0.05 1 2 3 4 owerri 120 8.6667 enugu 120 11.7500 11.7500 uyo 120 15.0000 15.0000 calabar 120 17.9167 17.9167 port harcourt 120 18.9167 sig. .070 .056 .086 .556 means for groups in homogeneous subsets are displayed. a. uses harmonic mean sample size = 120.000. analysis of variance of the spatial variation in the effects of sudden weather events in rainfall for sampled cities in table 4a (port harcourt, uyo, enugu, owerri and calabar) is significant at p<0.05 level, f 12.684, sig 0.000. since the significant level is below 0.05(p value). it indicates that there is a statistically significant difference amongst the five states. duncan statistics in table 4b was further computed to decipher where the variation in rainfall is conspicuous. the analysis revealed that owerri (m= 8.667), sig 0.070) is significantly varied from uyo (m= 15.000 sig 0.86) and varied from port harcourt (m= 18.9167, sig 0.556). mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 16 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 6c: anova table showing the spatial difference in the effects of sudden weather events (cloud-oktas) on aviation in the south east of nigeria anova cloud_oktas sum of squares df mean square f sig. between groups 227.667 4 56.917 13.651 .000 within groups 2480.833 595 4.169 total 2708.500 599 table 6d: duncan statistics showing the spatial difference in the effects of sudden weather events (cloud-oktas) on aviation in the south east of nigeria cloud-oktas duncan identifiers n subset for alpha = 0.05 1 2 3 calabar 120 1.5833 uyo 120 2.3333 owerri 120 2.4167 enugu 120 3.0833 port harcourt 120 3.3333 sig. 1.000 .752 .343 means for groups in homogeneous subsets are displayed. a. uses harmonic mean sample size = 120.000. analysis of variance of the spatial variation in the effects of sudden weather events in cloud -oktas for sampled cities (port harcourt, uyo, enugu, owerri and calabar) is presented in table 4c and it is significant at p<0.05 level, f 13.651 sig 0.000. since the significant level is below 0.05(p value). it indicates that there is a statistically significant difference amongst the five states. duncan statistics was further computed to decipher where the variation in cloud oktas is conspicuous. table 4d revealed that calabar (m= 1.5833), sig 1.000) is significantly varied from uyo (m= 2.333 sig 0.752) and varied from port harcourt (m= 3.333, sig 0.343) table 6e: anova table showing the spatial difference in the effects of sudden weather events (visibility) on aviation in the south east of nigeria anova visibility sum of squares df mean square f sig. between groups 44414.333 4 11103.583 125.345 .000 within groups 52707.500 595 88.584 total 97121.833 599 mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 17 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset table 6f: duncan statistics showing the spatial difference in the effects of sudden weather events (visibility) on aviation in the south east of nigeria visibility duncana identifiers n subset for alpha = 0.05 1 2 3 uyo 120 3.7500 calabar 120 3.8333 port harcourt 120 14.1667 owerri 120 14.2500 enugu 120 27.0833 sig. .945 .945 1.000 means for groups in homogeneous subsets are displayed. a. uses harmonic mean sample size = 120.000. analysis of variance of the spatial variation in the effects of sudden weather events in visibility for sampled cities (port harcourt, uyo, enugu, owerri and calabar) is presented in table 4e and it is significant at p<0.05 level, f 125.345 sig 0.000. since the significant level is below 0.05 (p value). it indicates that there is a statistically significant difference amongst the five states. duncan statistics was further computed to decipher where the variation in visibility is conspicuous. table 4f revealed that uyo (m= 3.7500, sig 0.945) is significantly varied from port harcourt (m= 14.1667 sig 0.45) and varied from enugu (m= 27.0883, sig 1.000) 4: discussion of results the critical characteristics of sudden and slow weather events over the years in south eastern nigeria were evaluated. the character of weather and climate showed changes in frequency, intensity, blip, spatial coverage, number of occurrences and timing. extremity of rainfall and cloud cover in port harcourt and uyo can be linked to their geographic location and dominance of the south west trade wind. the implication is that the tropical maritime gives more potency for cloud and rainfall to reduce visibility, and affect flight operations given the ubiquity of thunderstorms. enugu had higher wind speed, but its closeness to the northern part of the country would mean dominance of the tropical continental air-mass. rainfall, temperature, cloud cover, wind and cloud cover showed remarkable variation annually and monthly. rainfall showed lack of consistency in most of the years, but 2013 had a similar pattern, temperature ranged between 30 ⁰c to 35⁰c with enugu having the highest temperature maximum, and this is consistent with the dynamics of the various climate belts in nigeria. these findings are consistent with those of samson & sumi, (2019). this study has identified the slow and sudden weather events characteristics in the south east. what was very conspicuous is the spatiality of weather characteristics and similarities amongst port harcourt, uyo and calabar. they showed near similarities in rainfall, cloudiness and visibility which is consistent with the character of the sub equatorial climate. however, this finding is not in tandem with the finding of ogunrinde et al., (2023). the weather characteristics of enugu appeared mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 18 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset different and similar to that of the tropical hinterland climate, and have higher wind speed. however, all the sampled cities demonstrated that cloudiness is not very impactful on visibility. the study observed changes in weather characteristics in the decade under investigation, one deviation from the norm is that calabar which is a coastal town has lower wind speed than other cities, and recorded the most recent increase occurrences in rainfall of 34 evets in 2016. however, studies have shown that most of the disruption, delays and cancellations of flight are avoidable if human errors and negligence are tackled (borsky & unterberger, 2019). the changes in the sudden and slow weather and climate events in the south eastern nigeria is consistent with the environmental changes. but empirical evidences have shown that climate change is one of the defining contemporary issues that have been recognized as a major driver of change in the period under investigation. all the cities sampled showed remarkable differences in changes in precipitation, temperature, cloud cover and visibility. the wind in enugu which shares the characteristics of the tropical hinterland climate had more speed than other cities but with marked variation across the years. port harcourt recorded remarkable shift with double maxima of high rainfall events in 2013 (34 occurrences) and 2016 (39 occurrences). only 12 and 12 rainfall events recorded in port harcourt in 2014 and 2018 are the only similarities, but the difference between rainfall events of 12 which is the lowest and that of 2016 (39 events which is the highest is significant. the case of owerri where rainfall was recorded just ounces in 2016, 4 times 2015 and 2021 represent concrete evidence of climate. the only city that had one level of consistency in rainfall is uyo, but there is abrupt reduction in 2018 with only 8 events. these findings are in line with those of eludoyin & akinbode (2009), although ugochukwu, emmanuel, & lekia, (2023) reporter otherwise. adverse weather and climate events are external factors that determines the operations of airports operations globally, but there is perceived over generalization of the climatic parameters that causes more disruptions in various climate regions. this study showed concrete evidence of slow and sudden weather events and potential effects on flight operations in the south east, but there is spatial variation among the cities investigated. as also reported by uchechukwu et al. (2018). the effects of the sudden and slow events are multidimensional, one the one hand, it increases the cost of operations, and create a negative public perception for airlines that do not have the required expertise to be proactive, and minimize the effects on passengers. on the other hands, sudden weather events cause delays, flight cancelation and additional cost for travelers, it can also lead to fatalities. in most cases, delays occur when there is no accurate forecast of imminent sudden weather events, and when communication with passengers is poor. it has been established in the literature that weather events are not always controllable (oriola, 2014), however, the onus is in airlines to minimize cost and losses of productive hours for passengers. occurrences of heavy rainfall and strong wind are sudden, and occur at specific time of the day, but causes shift in disruption in logistics planning with economic cost for operators and passengers, but data on amount of departure delays in various airline companies is not availability for research (balogun & odjugo, 2020). the constancy of the effects of rainfall and cloud cover on visibility and airline operations in the decade under review is attributable to the dynamics in the sub equatorial and hinterland climate. similar observation has been made by borsky & unterberger, (2019), they however, averred that being acquainted with the weather and mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 19 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset climate characteristics of the locale is key to ameliorating the sudden and slow weather events effects of aviation operations. passengers are largely aware of the effects of weather events on air travels. over the years, financial losses, flight delays and cancelation and loss of opportunities have been recorded by passengers. but there is still no policy to compensate for poor service. evidently, flight travels are still largely patronized by the elites as there seem to be a correlation between literacy and the utility of air transport. only few passengers with basic education utilizes air transport in the sampled cities and they are obviously the respondents that are not aware of the effects of weather events on air travels (adefolalu, 2007). annual and decadal rainfall revealed steady increase from june to august and slight decrease from october to march. there is positive statistical relationship and variation in weather characteristics which also manifest in flight delays, cancellation and diversion. this is consistent with mande (2019) where he reported that 71% of air travel disruption in nigeria are due to the poor weather conditions, with the inclusion of human errors, aging aircraft and deficiency in safety management system. this case of full cloud in port harcourt also aligns with mande (2019) where he reported flight disruption in the city with reduced horizontal visibility to between 200 to 800 for several days leading to spiraling flight disruption across the country. 5. conclusion and recommendations it is obvious as captured in several studies in the literature that knowledge on weather phenomena is very important for flight operations while others revealed that adverse weather conditions may cause delays, diversions, accidents and even outright cancellations of journeys, causing loss of time, revenue and even lives. in addition, available reports maintained that in aviation, weather has remained the important parameter in determining safety, regularity and efficiency of aviation operations. the plethora of studies in the literature that interrogate the effects of weather parameters on aviation have obviously failed to differentiate between slow and sudden weather events. thus, there is perceived wrongful generalization and errors in responses to weather related problems in the aviation industry. this study has established the difference between slow and sudden weather events and disparity in weather characteristics amongst cities in the south east. it revealed that there are variations in cloudiness, rainfall and visibility amongst the cities and given the interconnectedness of aviation infrastructure and operations with weather parameters, disruption in one city leads to chain disruption in other cities resulting in flight disruptions. noting that the economic cost of flight cancelation, diversion and delays are not quantified and duly compensated, the need to device various methods to address the peculiarities of problems in various cities are necessary. on the premise of the above, the following recommendations are made: 1. improvement in the expertise of aviation staff through training and retraining to keep pace with effects of weather variability and change in airline operations. 2. migrating from analog data collection methods to automated instruments to engender real time and accurate data collection for planning due to the dynamic nature of atmospheric parameters. 3. enactment and enforcement of stringent regulations on airline companies to engender global best practices. 4. replacement of aging aircraft and weather monitoring facilities. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 20 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset 5. improvement in maintenance culture. 6. synergy between all airport services providers is needed to activate proactive planning, anticipate climate change and design appropriate resilience and adaptation plan.as well measures to tackle flight disruption, damage of airport infrastructure given the progression of rainfall and changing wind. 6. references abdelghany, a., guzhva, v. s., & abdelghany, k. (2023). the limitation of machine-learning based models in predicting airline flight block time. journal of air transport management, 107, 102339. adefolalu, d. o. (2007). climate change and economic sustainability in nigeria. in international conference on climate change and economic sustainability held at nnamdi azikiwe university, enugu, nigeria (pp. 12-14). ahmed, z., le, h. p., & shahzad, s. j. h. (2022). toward environmental sustainability: how do urbanization, economic growth, and industrialization affect biocapacity in brazil?. environment, development and sustainability, 24(10), 11676-11696. akpootu, d. o., iliyasu, m. i., mustapha, w., salifu, s. i., sulu, h. t., arewa, s. p., & abubakar, m. b. (2019). models for estimating precipitable water vapour and variation of dew point temperature with other parameters at owerri, south eastern, nigeria. journal of water resources and ocean science, 8(3), 2836. ayoade, j. o. (2004). introduction to climatology for the tropics ibadan. spectrum book. balogun, v. s., & odjugo, p. a. o. (2020). gender-based assessment of climate chang e adaptation strategies in delta state, nigeria. journal of geographic thought & environmental studies, 15(2), 94-110. bertness, j. (1980). rain-related impacts on selected transportation activities and utility services in the chicago area. journal of applied meteorology and climatology, 19(5), 545-556. borsky, s., & unterberger, c. (2019). bad weather and flight delays: the impact of sudden and slow onset weather events. economics of transportation, 18, 10-26. chen, z., & wang, y. (2019). impacts of severe weather events on high-speed rail and aviation delays. transportation research part d: transport and environment, 69, 168-183. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 21 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset dalal, s., seth, b., radulescu, m., cilan, t. f., & serbanescu, l. (2023). optimized deep learning with learning without forgetting (lwf) for weather classification for sustainable transportation and traffic safety. sustainability, 15(7), 6070. dalmau, r., & gawinowski, g. (2023). learning with confidence the likelihood of flight diversion due to adverse weather at destination. ieee transactions on intelligent transportation systems. dempsey, p. s. (2002). aviation security: the role of law in the war against terrorism. colum. j. transnat'l l., 41, 649. deng, x., wang, l., gui, j., jiang, p., chen, x., zeng, f., & wan, s. (2023). a review of 6g autonomous intelligent transportation systems: mechanisms, applications and challenges. journal of systems architecture, 102929. diamond, s. (2017). in search of the primitive: a critique of civilization. taylor & francis. dönmez, k. (2023). aircraft sequencing under the uncertainty of the runway occupancy times of arrivals during the backtrack procedure. the aeronautical journal, 127(1310), 562-580. eludoyin, a. o., & akinbode, o. m. (2009). millennium development goal on water supply and the challenges of headwaters quality in nigeria: example from a small community in southwest nigeria. journal of sustainable development in africa, 11(2), 178-93. ezemonye, m. n., & emeribe, c. n. (2012). rainfall erosivity in southeastern nigeria. ethiopian journal of environmental studies and management, 5(2), 112-122. glass, c., davis, l., & watkins-lewis, k. (2022). a visualization and optimization of the impact of a severe weather disruption to an air transportation network. computers & industrial engineering, 168, 107978. gnutzmann, h., & śpiewanowski, p. (2023). can consumer rights improve on-time performance? evidence from european air passenger rights. transport policy, 136, 155-168. hutter, f. g., & pfennig, a. (2023). reduction in ground times in passenger air transport: a first approach to evaluate mechanisms and challenges. applied sciences, 13(3), 1380. isagba, e. s., izinyon, o. c., emeribe, c. n., uwadia, n. o., & ezeh, c. u. (2021). estimation of stream discharge of ungauged basins using nrcs-cn and remote sensing methods: a case study of okhuwan mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 22 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset and okhaihe catchments, benin city, edo state, nigeria. international journal of water resources and environmental engineering, 13(3), 165-183. kumar, p., & khani, a. (2023). schedule-based transit assignment with online bus arrival information. transportation research part c: emerging technologies, 155, 104282. li, q., jing, r., & dong, z. s. (2023). flight delay prediction with priority information of weather and nonweather features. ieee transactions on intelligent transportation systems. lin, m. h. (2023). airport congestion pricing and capacity: cost recovery with per-flight or per-passenger charges. available at ssrn 4494785. mande, k. h. (2019). effect of climate change on airline flights operations at nnamdi azikiwe international airport abuja, nigeria. science world journal, 14(2), 33-41. montlaur, a., delgado, l., & prats, x. (2023). domain-driven multiple-criteria decision-making for flight crew decision support tool. journal of air transport management, 112, 102463. ogunrinde, a. t., oguntunde, p. g., akinwumiju, a. s., fasinmirin, j. t., adawa, i. s., & ajayi, t. a. (2023). effects of climate change and drought attributes in nigeria based on rcp 8.5 climate scenario. physics and chemistry of the earth, parts a/b/c, 129, 103339. okereke, c. a., & emeribeole, a. c. (2020). soil erosion as an emerging environmental challenges in southeast geopolitical zone of nigeria: towards a sustainable land conservation for national development. african journal of environment and natural science research, 3(1), oriola, a. o. (2014). system dynamics modelling of waste management system. in proceedings of 1st asianpacific system dynamics conference (pp. 22-24). porter, e. (2023). a people's history of sfo: the making of the bay area and an airport. univ of california press. reitmann, s., & schultz, m. (2022). an adaptive framework for optimization and prediction of air traffic management (sub-) systems with machine learning. aerospace, 9(2), 77. ren, j. (2023). financial conditions and incumbent quality responses to entry: evidence from airlines' on-time performance. journal of air transport management, 107, 102352. mailto:topacademicjournals@gmail.com academic journal of science, engineering and technology vol. 10, issue 5; september-october 2025; issn: 2837-2964 impact factor: 7.67 1252 columbia rd nw, washington dc, united states https://topjournals.org/index.php/ajset; mail: topacademicjournals@gmail.com 23 | a c a d e m i c j o u r n a l o f s c i e n c e , e n g i n e e r i n g a n d t e c h n o l o g y | https://topjournals.org/index.php/ajset samson, b. p. v., & sumi, y. (2019). exploring factors that influence connected drivers to (not) use or follow recommended optimal routes. in proceedings of the 2019 chi conference on human factors in computing systems (pp. 1-14). sytch, m., kim, y., & page, s. (2022). supplier-selection practices for robust global supply chain networks: a simulation of the global auto industry. california management review, 64(2), 119-142. uchechukwu, n. b., agunwamba, j. c., tenebe, i. t., & bamigboye, g. o. (2018). geography of udi cuesta contribution to hydro-meteorological pattern of the south eastern nigeria. engineering and mathematical topics in rainfall. ugochukwu, a., emmanuel, b. o., & lekia, n. (2023). bivariate time series analysis of rainfall pattern in selected states in nigeria. journal of mathematical sciences & computational mathematics, 4(4), 442461. voskaki, a., budd, t., & mason, k. (2023). the impact of climate hazards to airport systems: a synthesis of the implications and risk mitigation trends. transport reviews, 1-24. wang, x., jin, j. g., & sun, l. (2022). real-time dispatching of operating buses during unplanned disruptions to urban rail transit system. transportation research part c: emerging technologies, 139, 103696. mailto:topacademicjournals@gmail.com 