ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY & ENVIRONMENT
AZOJETE, September 2019. Vol. 15(3):534-553

Published by the Faculty of Engineering, University of Maiduguri, Maiduguri, Nigeria.
Print ISSN: 1596-2490, Electronic ISSN: 2545-5818

www.azojete.com.ng

534

ORIGINAL RESEARCH ARTICLE

EFFECT OF MOISTURE CONTENT ON SOME ENGINEERING PROPERTIES OF AFRICAN
MAHOGANY (Afzelia africana) SEED

N. A. Aviara1*, S. Ekaso Jr.1 and O. U. Nwanja2
(1Department of Agricultural and Environmental Resources Engineering,

University of Maiduguri, Maiduguri, Borno State, Nigeria
2Department of Agricultural Technology, Akanu Ibiam Federal Polytechnic, Unwana-Afikpo, Ebonyi State, Nigeria)

* Corresponding author’s email address: nddyaviara@yahoo.com

ARTICLE INFORMATION

Submitted 23 November, 2018
Revised 20 March, 2019
Accepted 25 March, 2019

Keywords:
Afzelia africana
physical properties
angle of repose
static and kinetic coefficients
of friction
coefficient of restitution
specific heat

ABSTRACT
Some engineering properties of Afzelia africana, namely axial
dimensions, one thousand seed mass, surface area, particle density,
bulk density, porosity, angle of repose, static and kinetic coefficients of
friction, coefficient of restitution and specific heat were determined as
a function of moisture content in the moisture range of 6.1 – 32.3%
(d.b). Results showed that in the above moisture range, major,
intermediate and minor axial dimensions of the seed increased from
25.4 – 26.2mm, 13.2 – 13.95mm and 10.2 – 11.2mm, respectively. One
thousand seed mass, surface area, particle density, porosity, angle of
repose, static coefficient of friction, kinetic coefficient of friction and
specific heat capacity of the seeds all increased with increase in
moisture content. Seed bulk density decreased with increase in
moisture content and coefficient of restitution decreased as drop
height and moisture content increased. The relationship existing
between the engineering properties and seed moisture content,
established using regression analysis showed high coefficient of
determination. These properties would be useful in the design of
Afzelia africana seed handling, storage and processing equipment.

© 2019 Faculty of Engineering, University of Maiduguri, Nigeria. All rights reserved.

1.0 Introduction
Afzelia africana also known as African mahogany (Figure 1) is an economically valuable and
drought resistant leguminous tree crop with its species widely distributed in the Continent of
Africa. It is found from Senegal in West Africa to the Sudan, Uganda and Tanzania in the East. It
is occasionally grown in other tropical countries as ornamental tree. Its uses range from foods to
pharmaceuticals. In West Africa, the edible seed is used in soup making as thickening agent. The
seed flour is used as a substitute for wheat flour in biscuits and doughnuts. Afzelia africana
seeds (Figure 2) have been reported to contain 24% protein, 4.29% crude fibre, 3.43% ash and
21% lipid (Matouk et al., 2004), indicating good nutritional value. The seeds help in softening
bulky stool and have been associated with protection against colon and rectal cancer.

Hydro gel is also found in the Afzelia africana seed and it is called Afzelia gum -a non starch
polysaccharide- which is useful in the food and pharmaceutical industries (Builders et al., 2009).

mailto:nddyaviara@yahoo.com
http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

535

With these numerous uses the popularity of this important seed has been limited because of
lack of proper handling equipment to project its commercial value.

Figure 1: Afzelia africana tree Figure 2: Afzelia africana seeds

In West Africa and Nigeria in particular, this important seed is subjected to such different
processing operations as soaking, roasting, parboiling, de-hulling, grinding and drying, prior to
utilization or storage. The present manual techniques of carrying out these operations are not
only labour intensive and time consuming, but also tasky with low output in terms of quantity
and quality of product. Therefore, there is the need to develop improved methods of handling
processing and storing the seeds using suitable machines and equipment. The development of
such machines and equipment require knowledge of the engineering properties of the seed. The
performance and adjustment of such machines are also dependent on the moisture content of
the produce (Aviara et al., 1999), therefore, the effect of moisture content on engineering
properties of Afzelia africana seed is an important consideration in the design of its handling
and processing equipment. No work however, appears to have been carried out of the
engineering properties of Afzelia africana seed and their relationship with seed moisture content.

The objective of this study was to determine some engineering properties of Afzelia africana
seed and investigate their relationship with moisture content. The properties include axial
dimensions, one thousand seed mass, surface area, particle density, bulk density, porosity, angle
of repose, static and kinetic coefficients of friction, coefficient of restitution and specific heat.
Relevant literature was studied in order to select the appropriate method of determining each of
the above properties. The selection of a method was based on simplicity, accuracy of results and
wide acceptability.

2. Materials and Methods
The bulk quantity of Afzelia africana seeds used in this study were purchased from Onueke in
Ebonyi State, and supplied by a marketer in Monday market, Maiduguri, Nigeria. The seeds were
taken to the laboratory and cleaned manually to remove all foreign materials and damaged
seeds. The market stable storage moisture of the seeds was determined by oven drying triplicate
samples at 105°C for 6 hours (Aviara et al., 1999).

The bulk seed was divided into 5 batches and conditioned by soaking in water for 12, 36, 58 and
84 hours including the market stable storage to obtain samples at five moisture levels for the

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 536

experiments. After conditioning, the seeds were poured separately into polyethylene bags and
sealed before being kept in a curing room for the three days to make the moisture distribute
uniformly throughout the grains. After the grains reached uniform moisture contents, the bags
were placed in desiccators and stored at room temperature.

To determine the amount of moisture content of seeds in the differently conditioned lots,
samples were collected and weighed using an electronic balance and placed in an oven set at
105°C with weight loss monitored on hourly basis until three consecutive weighing gave
identical values of mass.
The moisture content was calculated from the relation used by Aviara (2005 b).

��ࠀ� � ��−��
��

� ��� (1)

where: Mw.b = Wet basis moisture content (%), Wi = Initial weight (g) and Wf = Final weight (g)
It was converted to dry basis moisture content by using the relation:

��� �
�ࠀ�

�tࠀ��
� ��� (2)

where: Md.b = Dry basis moisture content (%).

The axial dimensions of the seed, namely: the length (L), width (B), and thickness (T) were
measured using the method of Ndukwu (2009). The dimensions of 100 randomly selected seeds
at different moisture contents were measured using a Venier calliper of 0.01mm accuracy in
order to determine the seed size. The average values of length, width and thickness of the seeds
at each moisture content were recorded.
The geometric mean diameter was determined by applying the length, width and thickness of
the seeds to Equation (3) (Joshi et al., 1993)

Dp = (LWT)1/3 (3)

where: Dp = Geometric mean diameter (mm), L= Length (mm), W= Width (mm) and T=
Thickness (mm)
Arithmetic mean diameterwas determined by using Equation (4) (Mohsenin, 1986).

Am = �����
�

(4)

where: Am = Arithmetic mean diameter. (mm)
The aspect ratio was determined using Equation (5):

Ra = �
�

(5)

where: Ra = Aspect ratio, W= Width (mm) and L= Length (mm)

The surface area of the seed was measured using the method of Ndukwu (2009). This involved
carefully wrapping the seeds completely with a foil paper and cutting of the edges. The paper
was then unwrapped and placed on a graph sheet. The outline covered by the foil paper on the
graph sheet was traced with a pencil and the surface area of the seeds was determined by

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

537

method of counting the squares. This was carried out at each moisture level using 30 seeds. The
average surface area of the seeds at various moisture contents was then obtained.

The one thousand seed weight was determined using the method of Taimirat, (2011). It involved
counting 1000 seeds and pouring them dockage free into a bucket of known weight.The seeds
and bucket was weighed using an electronic balance of approximately 0.001g reading accuracy.
The mass of the bucket was subtracted from the mass of the 1000 seeds plus bucket and the
mass of the 1000 seeds at each moisture content was recorded.
The true density of Afzelia africana seeds was determined using the standard liquid
displacement method as reported by Aviara et al. (1999).The samples were coated with epoxy
resin around the ring, weighed individually on an electronic balance and tied with a thread
before immersing them individually into a 25ml cylinder containing water to a known level. The
volume of water displaced in the cylinder was noted and taken in order to obtain the volume of
the seed. 30 trials were carried out at each moisture level.
True density was then calculated from the obtained values using the formula:

ρt = �
��−��

(6)

where: ρt = True density (kgm-3), M = Mass of individual seed (kg), Vi = Initial volume of water
in the cylinder (m3) and Vf = Final volume of water in the cylinder after submergence of seed
(m3).
The bulk density was determined using the AOAC (1980) method. Samples were poured from a
height of 15cm into a 500ml cylinder of known mass. The cylinder containing samples was
weighed on abalance and weight of the seeds was obtained by subtracting the mass of the
cylinder from the final mass of seeds and cylinder, while the volume of the cylinder was taken as
the volume occupied by the seeds.

Bulk density was then determined using the expression:

ρb = (Ms / Vs) (7)

where: ρb = Bulk density (kg/m3), Ms = Mass of seeds alone (kg) and Vs = Volume of seeds (m3)

The porosity of Afzelia Africana seeds were determined using the formula (Mohsenin, 1986)

� � � t ρb
ρt

� ��� (8)

where: � = Porosity (%), ρb = Bulk density (kg/m3) and ρt = True density (kg/m3)

In determining the angle of repose, the cylindrical pipe method reported by Zewdu and
Solomon (2007) was used. A topless and bottomless cylinder placed on a flat surface was filled
with seeds at specified moisture content and slowly raised until it completely gets lifted off from
the seeds leaving them to pile in form of a cone. The diameter and height of the cone were
measured using a Venier calliper and used to calculate the angle of repose. The formula
(Equation 9) given by Zewdu and Solomon (2007) was applied to determine the angle of repose.

� � tan−� h
�

(9)

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 538

where: � = Angle of repose in degrees, h = height of piled seeds (mm) and r = Radius of base of
cone formed by seeds (mm)

Static coefficient of friction of the seeds on different structural surfaces (steel sheet, wood,
hessian bag and glass)was determined using the inclined plane method as described by Dutta et
al. (1988) and Suthar and Das (1996). This involved the placing of an open-ended box (50mm ×
100mm × 100mm) on an adjustable tilting surface which was formed with structural surface. The
box was filled with seeds at specified moisture content and the structural surface with the box
and its content on top was gradually raised using a screw device until the box started to slide
down and the corresponding tilting angle, α was recorded.
The value of static coefficient of friction was calculated using Equation (10) due to Mahapatra et
al. (2002).

(10)
where: � = static coefficient of friction and α = tilting angle
For the kinetic coefficient of friction, the open-ended box was used as described by Aviara et al.,
(2000). In this method, the box was placed on a horizontal surface. The box was filled with seeds
and connected by means of a string, parallel to the surface and passed over a pulley to a pan
hanging down from it. Weights were placed in the pan subsequently until the box and its
content moved uniformly when given a gentle push. The kinetic coefficient of friction of the
seeds on a given structural surface was determined using Equation (11). Four different surfaces
were used for each moisture level of the seeds namely and these were plywood, fibre glass,
hessian bag material and steel sheet.

� � �t ���
�� ��香

(11)

where: � = Kinetic coefficient of friction, Wp = Weight of pan (g), Wi = Weight placed in pan to
move the box (g), Wb = Weight of box (g) and Ws = Weight of sample (g).

Coefficient of restitution of the seeds was determined using the method described by Kumar
(1995). The nuts were dropped from a height of 50, 90, 120, and 150 cm on four structural
surfaces namely: wood, galvanised steel sheet, hessian bag and fibre glass. A graduated scale
was kept at the background and the maximum height of rebound was recorded using a video
camera. This was replicated three times at each moisture content level for seed fall on both axial
and longitudinal orientation. The coefficient of restitution was calculated using Equation (12) as
given by Aviara et al. (2010):

��� � h
�

(12)

where: C.R is the coefficient of restitution, h = Height of rebound (cm) and H = Height of drop
(cm).
Coefficient of restitution on each surface for different drop heights was regressed against
moisture content.
The specific heat of the seeds was determined using a copper calorimeter placed inside a flask
by method of mixtures as described by Ogunjimi et al., (2002). A sample of known weight and
temperature was poured into calorimeters containing water of known weight and temperature.

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

539

The final temperature was noted and the specific heat of the sample was calculated using
Equation (13):

Cs = �t�tࠀ�ࠀ�� �t−ࠀ�
�香 �t−�香

(13)

where: Cc = Specific heat of calorimeter (J/kgK), Cs = Specific heat of sample (J/kgK), Cw =
Specific heat of water (J/kgK), Mc = Mass of calorimeter (kg), Ms = Mass of sample (kg), Te =
Equilibrium temperature of seed (K), Ts = Initial temperature of sample (K) and Tw = Initial
temperature of water (K).
The experiments were replicated thrice at each moisture content except in cases otherwise
stated and the average values of the properties were recorded. The relationship existing
between the properties and seed moisture content as well as the coefficient of determination of
the equation used to express the relationship were determined using regression procedure. The
variation of the engineering properties with moisture content was also expressed graphically.

3. Results and Discussion
3.1 Seed Moisture Content
The initial moisture content of Afzelia africana seeds was found to be 6.1% (d.b). The four other
moisture levels obtained after conditioning the seeds were 7.9, 12.8, 25.4 and 32.3% (d.b),
respectively. The investigations were carried out at the above moisture levels to determine the
effect of moisture content on the physical, frictional and thermal properties of Afzelia africana
seeds.
3.2 Axial Dimensions
The variation of the Afzelia africana seed size measured at different moisture content levels is
presented in Figure 3.

Figure 3: Effect of moisture content on the axial dimensions of Afzelia africana seed

The Figure shows that the three axial dimensions increased with increase in moisture content in
the moisture range of 6.1 – 32.3% d.b. Major axis increased from 25.4 – 26.2mm, the
intermediate axis increased from 13.2 – 13.95mm and the minor axis from10.2 – 11.2mm. The
arithmetic and geometric mean axial dimensions also increased with increase in moisture
content. The arithmetic mean had higher values than the geometric mean axial dimensions of
the seeds. The aspect ratio which is the ratio of the intermediate axis to the major axis also

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 540

increased with increase in moisture content. The increase in axial dimensions indicates that upon
increase in moisture contents, the seeds expand in length, width and thickness thereby
increasing their average dimensions.

The relationship between moisture content and the axial dimensions of the seeds was found to
be linear with the following equations:

a = 0.26M + 9.92 (14)
b = 0.205M + 25.095 (15)
c = 0.19M + 13 (16)
Am = 0.214M + 16.022 (17)
Dp = 0.237M + 14.373 (18)
Ra = 0.0032M + 0.5181 (19)

with values of coefficient of determination R2 = 0.9298, 0.9941, 0.981, 0.9745, 0.9454 and 0.9063
respectively.
where: a = Major axis (mm), b = Intermediate axis (mm), c = Minor axis (mm), Am = Arithmetic
mean dimension (mm), Dp = Geometric mean dimension (mm), Ra = Aspect ratio and M =
Moisture content (%, db).
Similar results of increase are reported by Tavakkoli et al., (2009) for the soybean grains and Al-
Mahasneh and Rababah, (2007) for green wheat. The results of the axial dimensions can be used
in sizing, mechanical separation and grading of Afzelia africana seeds from similar sized
materials such as stones. Irtwange and Igbeka (2002) and Aviara et al., (2005b) observed similar
trend of arithmetic and geometric mean dimensions for African yam bean and sheanut
respectively.

3.3 One Thousand Seed Weight
The variation of one thousand seed weight of Afzelia Africana with moisture content is
presented in Figure 4.

Figure 4: The effect of moisture content on the one thousand seed weight of Afzelia africana
seed

Figure 4 shows that one thousand seed weight increased from 2.4 – 2.8kg in the moisture range
of 6.1 – 32.3% d.b. This positive trend of one thousand seed weight with moisture content was
due to increase in weight gained by the presence of more water thereby producing a heavier
seed.

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

541

The relationship between moisture content and mass of one thousand seeds was seen to be
linear and can be expressed with the following equation:

W1000 = 0.101M + 2.287 (20)
with value of coefficient of determination R2 = 0.9697, where W1000 is the one thousand seed
weight (kg).
Similar trend was reported by Irtwange and Igbeka, (2002) for African yam bean, Kaleemullah
and Gunasekar, (2002) for arecanut, Aviara et al., (2005b) for sheanut, Isik, (2007) for round red
lentil grain and Simoyan et al., (2007) for Samaru sorghum. This result on seed mass can be
applied practically in the design of equipment for cleaning, separation, conveying and elevating
unit operations. It can also be used to estimate the overall bulk weight of Afzelia africana seeds
during bulk handling.

3.4 Particle Density
The effect of moisture content on particle density of Afzelia africana seeds is presented in Figure
5.

Figure 5: Effect of moisture content on the particle density of Afzelia africana seed

The Figure shows that particle density increased from 1190 – 1446kg/m3 as the moisture
content increases from 6.1 – 32.3% d.b. The increase in particle density of Afzelia africana seeds
with increase in moisture content may be due to the higher rate of increase in mass of the
individual seeds than its volume as the moisture content increased. The relationship existing
between particle density and moisture content was found to be linear and can be represented by
the regression equation:

ρt= 65.2M + 1109.6 (21)

with correlation coefficient of R2 = 0.9622, where: ρt = Particle density (kg/m3).

Baumler et al., (2006) and Coskuner and Karababa (2007) reported polynomial relationship
between particle density and moisture content for safflower and coriander seeds respectively. An
increase in particle density had also been reported by Perez-Alegria et al., (2001) for parchment
coffee bean, Ozarslan, (2002) for cotton seed, Aviara et al., (2005 a) for Balanites aegyptiaca nuts,
Aviara et al., (2005 b) for sheanut and Isik (2007) for round red lentil grain. The particle density of
agricultural products have been reported to play significant importance in the design of silos
and storage bins, maturity and quality evaluation of products which are essential to grain

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 542

marketing (Irtwange and Igbeka, 2002) and also could prove useful in the separation and
transport of the seeds by hydrodynamic means (Omobuwajo et al., 2003).

3.5 Bulk Density
The effect of moisture content on the bulk density of Afzelia africana seeds is shown in Figure 6.

Figure 6: Effect of moisture content on the bulk density of Afzelia africana seed

Bulk density was found to decrease from 670 – 626kg/m3 as the moisture content increased
from 6.1 – 32.2% (d.b). It was seen that as the moisture content increased, the size of the seeds
increased resulting in less mass and amount of seeds occupying equal bulk volume. Therefore,
the decrease in bulk density of the seeds resulted from increase in size with moisture content.
Also, the resistance of the seeds to consolidation may have increased with moisture content as a
result of increase in internal pressure. The relationship existing between moisture content and
bulk density was observed to be a power law relationship and it’s further represented by the
equation:

ρb = 665.78M -0.041 (22)

with the coefficient of determination R2 = 0.9379, where: ρb = Bulk density (kg/m3).

Carman (1996), Gupta and Das (1998), and Visvanathan et al., (1996) found the bulk density of
lentil seeds, sunflower seeds and neem nuts, respectively, to decrease as the seed moisture
content increases. Bulk density is applied practically in the calculation of thermal properties in
heat transfer problems, in determining Reynold’s number of materials and in predicting
pressures in storage structures as well as chemical composition.

3.6 Porosity
The porosity of Afzelia africana seeds calculated from relevant experimental data in the moisture
range of 6.1 – 32.2% (d.b) increased from 43.7 – 56.6%. The effect of moisture on porosity is
presented in Figure 7.

Figure 7: Effect of moisture content on the porosity of Afzelia africana seed

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

543

The increase in porosity may bedue to decrease in compaction and increase in void spaces
within the grain mass as bulk density decreased, invariably increasing the porosity of the seed in
bulk. This may be expected because the larger the size of an object, the more loosely packed it
becomes. The relationship existing between moisture content was found to be linear and can be
represented with the equation:

ԑ = 3.46M + 39.58 (23)

with coefficient of determination R2 = 0.9809, where: ԑ = Porosity (%).

The dependence of porosity on true and bulk densities are definitely different for each seed or
grain with increasing moisture content. A decrease in porosity with moisture content was
reported by Irtwange and Igbeka (2002) for African yam bean. Chowdhury et al., (2001) and
Konak et al., (2002) reported a linear increase in porosity with increase in moisture content for
gram and chick pea seed. Baryeh (2002) and Coskuner and Karababa (2007) reported a
polynomial relationship between porosity and moisture content for millet seeds and coriander
seeds. These results indicate that porosity of seeds of different crops could respond differently in
manner, which could be dependent on their morphological characteristics.

3.7 Surface Area
The effect of moisture content on the surface area of Afzelia africana seeds is presented in
Figure 8.

Figure 8: Effect of moisture content on the surface area of Afzelia africana seed

The surface area of Afzelia africana seeds increased from 8.3 – 8.52cm2 in the moisture range of
6.1 – 32.3% (d.b). The increase in surface area is mainly due to the increase in the linear
dimensions with increase in moisture content thereby resulting in increased volume causing the
seeds to occupy a larger area. The relationship found between moisture content and surface
area of the seeds was logarithmic and can be expressed using the equation:

Sa = 0.1248ln (M) + 8.0841 (24)

with the coefficient of determination R2 = 0.9913, where: Sa = Surface area (cm2).The trend of
increasing surface area with moisture content have been reported by Fatholahzadeh et al. (2008)
for Apricot kernel from 282.35 – 297.24mm2, and Isik (2007) for soybean grains from 118.756 –
197.654 mm2. Aviara et al. (2014) reported the seed surface area of Brachystegia eurycoma seeds

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 544

to increase from 7.67 – 8.48cm2. Also, Tavakoli et al. (2009) reported the surface area for barley
grains to increase linearly from 56.66 – 71.09mm2.

3.8 Angle of Repose
The variation of angle of repose with moisture content is shown in Figure 9.

Figure 9: Effect of moisture content on angle of repose of Afzelia africana seed

From the Figure, it was observed that the angle of repose increased from 27.7 – 34° as the
moisture content increased from 6.1 – 32.3% (d.b). It was also observed that at higher moisture
content within the above range, seeds tend to stick together resulting in better stability and less
flowability, which must have resulted in increases in the value of θ. The relationship between
moisture content and the angle of repose of the seeds was found to be linear with the equation:

θ = 0.2437M + 26.042 (25)

with the coefficient of determination R2 = 0.9966, where: θ = Angle of repose (°).
A linear relationship between angle of repose and moisture content was also observed for cumin
seed and coriander seed (Singh and Goswani, 1996; Yalcin and Ersan, 2007). However, a
logarithmic relationship was observed for okra seed and sheanut (Sahoo and Srivastava, 2002;
Aviara et al., 2005) respectively. This property is used in the design of discharging equipment for
particulate solids.

3.9 Static Coefficient of Friction
The static coefficient of friction obtained experimentally on four structural surfaces against
moisture content in the range of 6.1 – 32.3% (d.b) is presented in Figure 10.

Figure 10: Effect of moisture content on the static coefficient of friction of Afzelia africana seed

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

545

It was seen that the static coefficient of friction of Afzelia africana seeds initially decreased with
increase in moisture content for wood and hessian bag but later increased at higher moisture
content of the experimental range, while it completely increased on galvanised steel sheet and
fibre glass. The static coefficient of friction varied according to the surface. It could be said that
at higher moisture content, the seeds became rough thereby increasing friction characteristics.
The static coefficient of friction was maximum on hessian bag (0.528 – 0.595), followed by wood
(0.485 – 0.581), galvanised steel sheet (0.385 – 0.507) and was minimum on fibre glass (0.325 –
0.456).
The relationship existing between moisture content and the static coefficient of friction of Afzelia
africana seeds for different structural surfaces were found to be linear and can be expressed with
the following equations:

μhb = 0.019M + 0.4962 (26)
μw = 0.0264M + 0.4428 (27)
μgs = 0.0298M + 0.3652 (28)
μfg = 0.0341M + 0.2873 (29)

with values of coefficient of determination R2 = 0.8907, 0.9033, 0.9691, and 0.9904 respectively.
where: μhb = Static coefficient of friction on hessian bag, μw = Static coefficient of friction on
wood, μgs = Static coefficient of friction on galvanised steel sheet, μfg = Static coefficient of
friction on fibre glass.

Singh and Goswani (1996), Milani et al., (2007) and Kheiralipour et al., (2008) reported linearly
increasing trends on the static coefficient of friction for cumin seed, cucurbit seed and wheat
respectively. This property is very useful in the product movements during processing. In the
design of silos, bins and other storage facilities for the seed, the vertical load on the walls of the
structure or equipment is determined by the friction coefficient.

3.10 Kinetic Coefficient of Friction
The kinetic coefficient of friction obtained experimentally on four structural surfaces against
moisture content in the range of 6.1- 32.3% (d.b) is presented in Figure 11

Figure 11: Effect of moisture content on the kinetic coefficient of friction of Afzelia africana seed

The Figure shows that the kinetic coefficient of friction increased with increase in moisture
content and well varied with structural surface.The highest friction coefficient was recorded on
hessian bag (0.536 – 0.63), followed by fibre glass (0.42 – 0.563) and galvanised steel sheet

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 546

(0.321 – 0.509), while the least was recorded for wood (0.321 – 0.482). This could be due to the
surface characteristics of the seeds with increasing moisture content.
The relationship existing between moisture content and the kinetic coefficient of friction of
Afzelia africana seeds for different structural surfaces were found to be linear and can be
expressed with the following equations:

μhb = 0.0254M + 0.4948 (30)
μw = 0.0409M + 0.2815 (31)
μgs = 0.0506M + 0.255 (32)
μfg = 0.0389M + 0.3711 (33)

with values of coefficient of determination R2 = 0.8848, 0.9932, 0.9702, and 0.9713 respectively.
where: μhb = Kinetic coefficient of friction on hessian bag, μw = Kinetic coefficient of friction on
wood, μgs = Kinetic coefficient of friction on galvanised steel sheet, μfg = Kinetic coefficient of
friction on fibre glass.
Carman (1996), Ebubekir et al. (2004) and Sessiza et al. (2007) reported linear increase of kinetic
coefficient of friction for lentil seed, fenugreek seeds and capper fruit seeds, respectively.
Kinetic coefficient of friction is needed before the power requirements for continued flow of
granular or unconsolidated materials can be estimated.

3.11 Coefficient of Restitution
The variation of the coefficient of restitution of Afzelia africana seeds with moisture levels in the
range 6.1 – 32.3% (d.b), drop heights between 50 – 150cm and different structural surfaces
namely Hessian bag, wood, fibre glass and galvanised steel sheet are presented in Figures 12 –
15.

Figure 12: Effect of moisture content on the coefficient of restitution of Afzelia africana seed
from a drop height of 50cm

Figure 13: Effect of moisture content on the coefficient of restitution of Afzelia africana seeds
from a drop height of 90cm

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

547

Figure 14: Effect of moisture content on the coefficient of restitution of Afzelia africana seeds
from a drop height of 120cm

Figure 15: Efect of moisture content on the coefficient of restitution of Afzelia africana seeds
from a drop height of 150cm

Coefficient of restitution decreased with increase in drop height and also decreased with
increase in moisture content and exhibited a linear relationship with moisture content on all the
surfaces. The decrease in the coefficient of restitution appeared to be almost entirely as a result
of increased impact velocity at increased drop heights. The non-spherical seed’s impact on a
point increased the local stress in the material, thus causing reduction in coefficient of restitution.
The relationship between coefficient of restitution and moisture content on all surfaces at
various heights can be expressed using linear equations of the form:

C.R = xM + y (34)

where: C.R = Coefficient of restitution, x and y are constants and M = Moisture content (%).
The constants in Equation (34) obtained for the seeds on different structural surfaces and drop
heights with the coefficients of determination are presented in Table 1.

It was also observed that coefficient of restitution depends not only on the impact velocity but
also on the seed composition and structural surface roughness as the highest coefficient of
restitution was observed on wood, followed by galvanised steel sheet, fibre glass and least on

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 548

hessian bag at all drop heights. Aviara et al. (2010) and LoCurto et al. (1997) reported decrease in
the coefficient of restitution with increase in moisture content and drop height for Mucuna
flagellipes and Soy bean respectively. Decrease in coefficient of restitution was also reported by
Jayan and Kumar (2004) for maize and red gram and by Ozturk et al. (2010) for chickpea and
lentil seeds.

Table1: Values of the constants in Equation (34) expressing the coefficient of restitution of
Afzelia africana seeds as a function of moisture content at different drop heights on different
structural surfaces
Structural surfaces Drop

Heights (cm)
Constants R2

x y
Hessian bag 50 -0.0025 0.186 0.908

90 -0.0011 0.1415 0.7593
120 -0.0008 -0.134 0.8469
150 -0.0005 -0.1226 0.7304

Fibre glass 50 -0.0017 0.2681 0.9959
90 -0.0015 0.2174 0.8217
120 -0.0014 0.2129 0.9765
150 -0.0013 0.2027 0.9264

Galvanised steel sheet 50 -0.0016 0.3424 0.965
90 -0.0009 0.2628 0.9674
120 -0.0008 0.2508 0.9767
150 -0.0007 0.2374 0.8438

Wood 50 -0.0014 0.3943 0.7457
90 -0.0011 0.3085 0.9284
120 -0.0009 0.2898 0.91
150 -0.0006 0.2712 0.8887

3.12 Specific Heat
The variation of specific heat of Afzelia africana seeds with moisture content in the range of 6.1 –
32.3% (d.b) is presented in Figure 16.

Figure 16: Effect of moisture content on the specific heat capacity of Afzelia africana seeds

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

549

It was observed that the specific heat of Afzelia africana seeds increased linearly with increase in
moisture content from 2080.3 – 5488.2J/kgK. The relationship between moisture content and the
specific heat capacity of the seeds can be further expressed using the linear equation:

Cs = 133.03M + 1215.2 (35)

with the value for the coefficient of determination R2 = 0.997, where: Cs = Specific heat capacity
of the seeds (J/kgK) and M = Moisture content (%, db).

Desphande and Bal (1999), Aviara and Haque (2001) and Aviara et al., (2008) reported a similar
trend of linear increase in specific heat for cumin seeds, sheanut kernel and guna seeds and
kernel, respectively. Knowledge of the specific heat of seeds as well as the effect of moisture
content and temperature on it value is essential for the design of thermal processing systems, as
varying moisture content and temperature could form some of the process conditions. The
thermal properties of the seed are also essential in the development of processes and
equipment needed in drying and storage.

4.0 Conclusion
This study investigated the moisture dependence of some engineering properties of Afzelia
africana seeds (axial dimensions, arithmetic mean diameter, geometric mean diameter, aspect
ratio, one thousand seed weight, surface area, particle density, bulk density, porosity, angle of
repose, static and kinetic coefficient of friction, coefficient of restitution and specific heat)in the
moisture range of 6.1 – 32.3% d.b. The outcome of the study revealed that the major,
intermediate and minor axial dimensions, the arithmetic and geometric mean diameters as well
as the aspect ratio of Afzelia africana seed increased linearly with moisture content. One
thousand seed weight, particle density, porosity and angle of repose also increased linearly as
the moisture content increased. Surface area of the seed increased logarithmically with increase
in moisture content, while bulk density decrease at a trend that had power relationship with
increase in moisture content. Static coefficient of friction increased linearly with moisture content
and varied with structural surfaces with the highest values being on hessian bag, followed by
wood, steel and the least on glass. Kinetic coefficient of friction also increased linearly with
moisture content and its highest values were on hessian bag, followed by glass, galvanised steel
sheet and the least was on wood. Coefficient of restitution decreased with increase in drop
height as well as increase in moisture content and varied with surface. Specific heat of the seeds
increased linearly with moisture content and ranged from 2080.3 – 5488.2J/kgK.

References
Atlantus, E. and Yaldiz, M. 2007. Effect of moisture content on some physical properties of faba
bean grain. Journal of Food Engineering, 78:174-183.
Amin, MN., Hossani, MA. and Roy, KC. 2004. Effects of moisture content on some physical
properties of lentil seeds. Journal of Food Engineering, 65(1): 83-87.
AOAC, (1980). Official Methods of Analysis (13th ed.). Washington, DC: Association of Official
Analytical Chemists.
Aviara, NA., Haque, MA. and Ogunjimi, LAO. 2008. Thermal properties of guna seed.
International Agrophysics, 22:291-297.
Aviara, NA., Haque, MA. and Izge, IA. 2000. Physical and frictional properties of sheanut. Agro
Science, 2(1):19-34.

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 550

Aviara, NA. and Haque, MA. 2001. Moisture dependence of thermal properties of sheanut kernel.
Journal of Food Engineering, 47(2):109-113.
Aviara, NA. and Haque, MA. 2000. Moisture dependence of densities, coefficient of friction and
angle of repose of guna seed and kernel. Journal of Engineering Application, 2:44-53.
Aviara, NA., Ajibola, OO. and Oni, SA. 2003. Effect of moisture content and temperature on the
specific heat of soybean TGX 1440-IE. Proceedings of the 4th International Conference of the
Nigeria Institution of Agricultural Engineers, 25:183-193.
Aviara, NA., Gwandzang, MI. and Haque, MA. 1999. Physical properties of guna seeds. Journal of
Agricultural Engineering Research, 73:105-111.
Aviara, NA. and Haque, MA. 2002. Processing and storage of guna crop in the North East Arid
Region of Nigeria. Agricultural Mechanization in Asia, Africa and Latin America, 33:49-54.
Aviara, NA., Onuh, OA. and Ehiabhi, SE. 2010. Phyisical properties of Mucuna Flagellipes nuts.
GSB seed Science and Biotechnology, 4(1): 59-68.
Aviara, NA., Oluwole, FA. and Haque, MA. 2005. Effect of moisture content onsome physical
properties of sheanut (Butyrosperm Paradoxum). International Agrophysics, 19:193-198.
Aydin, C., Ogut, H. and Konak, M. 2002. Some physical properties of Turkish Mahaleb. Biosystems
Engineering, 82(2):231-234.
Barbosa-Canovas, GV., Juliano, P. and Palag, M. 2004. Engineering property of Foods, in Food
Engineering (Ed. Gustavo V. Barbosa-Canovas). In Encyclopaedia of the Support Systems (EOLSS),
developed under the auspices of the UNESCO, EOLLAS publishers, OXFORD, UK,
(http://www.eolass.net).
Baryeh, EA. 2002. Physical properties of millet. Journal of Food Engineering, 51:39-46.
Brenan, JPM. 1967. Leguminosae, subfamily Caesalpnoideae In: Milne-Redhead, E. and Polhill,
RM. (Eds). Flora of tropical east Africa: crown agents for Overseas Governments and
Administrations, London, United Kingdom. 230 pp.
Burkill, HM. 1995. The useful plants of west tropical Africa. 2nd Edition. Volume 3, families J – L.
Royal botanic gardens, Kew, Richmond, United Kingdom. 857 pp.
Burubai, W., Akor, AJ., Igoni, AH. and Puyate, YT. 2007. Some physical properties of African
nutmeg (Monotora Mystica). International Agrophysics, 21:123-126.
CAB 2005. CAB InternationalForestry Compendium:Afzelia Africana. [Internet]
http://www.cabicompendium.org/fc/datasheet.asp? Downloaded 14/6/2015.
Carman, K. 1996. Some physical properties of Lentil seeds. Journal of Agricultural Engineering
Research, 63:87-92.
Cetin, M. 2007. Physical properties of barbunian bean (Phaseolus Vulgaris L.Cv. ‘Barbunia’) seed.
Journal of Food Engineering, 80:353-358.
Chung, JH. and Verma, LR. 1989. Determination of friction coefficients of peanuts. Transactions
of the ASAE. 745-750.
Coskun, MB., Yalcin, I. and Ozarslan, C. 2006. Physical properties of sweet corn seed (Zea mays
Saccharastasturt). Journal of Food Engineering, 74:523-528.
Desphande, SD. and Bal, S. 1999. Specific heat of soybean. Journal of Food Processing
Engineering, 22:469-477.

http://www.eolass.net
http://www.cabicompendium.org/fc/datasheet.asp
http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

551

Desphande, SD., Bal, S. and Ojha, TP. 1993. Physical properties of soybean. Journal of Agricultural
Engineering Resources, 56:89-98.
Dursun, E., and Dursun, I. 2005. Some physical properties of caper seed. Biosystems Engineering,
92(2):237-245.
Dutta, SK., Nema, VK. and Bhardwaj, RK. 1988a. Physical properties of gram. Journal of
Agricultural Engineering Research, 39:269-275.
Dutta, SK., Nema, VK. and Bhardwaj, RK. 1988b. Thermal properties of gram. Journal of
Agricultural Engineering Research, 39:259-268.
Ebubekir, N., Eugin, O. and Faruk, OT. 2004. Some physical properties of Fenugreek seeds.
Journal of Food Engineering, 71:37-43.
Eke, CNU., Aseogwu, SN. and Nwandikom, GI. 2007. Physical properties of Jackbean (Carnavatia
Ensiformis). Agricultural Engineering International: The CIGR e-journal, manuscript of FP 07 014.
Garnayaka, DK., Pradhana, RC., Narka, SN. and Bhatnagar, N. 2008. Moisture dependent physical
properties of Jatropha seed. Industrial Crops and Products, 27(1):123-129.
Gupta, RK. and Das, SK. 1997. Physical properties of sunflower seed. Journal of Agricultural
Engineering Research, 66:1-8.
Igbozulike, AO. and Aremu, AK. 2009. Moisture dependent physical properties of Garcinia kola
seeds. Journal of Agricultural Technology, 5(2):239-248.
Irtwange, SV. and Igbeka, JC. 2002. Selected moisture dependent frictional properties of two
African yam bean accessions. Applied Engineering in Agriculture, 18(5):559-565.
Joshi, DC., Das, SK. and Mukherjee, RK. 1993. Physical properties of pumpkin seed. Journal of
Agricultural Engineering Research, 54:219-229.
Kazarian, EA. and Hall, CW. 1965. The thermal properties of grains. Transactions of the ASAE,
31:33-37/40.
Keranmat, JM., Jafari, A., Rafiee, S., Keyhani, AR. and Mirasheh, R. 2007. Somephysical properties
of date fruit (Cv. Lasht). Agricultural Engineering International: The CIGR e-journal manuscript FP
019, Vol. IX. August, 2007.
Kheirahipour, K., Karimi, M., Tabatabaeefar, A., Nadari, M., Khoubaht, G. and Heidarbeigi, K. 2008.
Moisture dependent physical properties of wheat (triticum aestivum L.). Journal of Agricultural
Technology, 4(1):53-64.
Kocabiyik, HA., Kayisoglu, BB. and Tezer A. 2009. Effect of moisture content on the thermal
properties of pumpkin seed. International Journal of Food Properties, 12(2):277-285.
Louppe, D. 2000. Afzelia Africana: une essence precieuse et plastique. Poster abstract. In: UFRO.
Forests and Society: the role of research. Vienna, Austria.
Oteng-Amoako, AA. 2006. 100 Tropical African Timber Trees from Ghana: tree description and
wood identification with notes on distribution, ecology, silviculture, ethnobotany and wood uses.
304 pp.
Madubike, FN., Ojimedukwe, PC. and Ajah, PO. 1994. Proximate composition, energy content of
Afzelia Africana and Brachystegia Eurycoma seeds. Plant Foods for Human Nutrition, 46(4):339-
344, Dol:10.1007/BF 010884304.

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng


Aviara, et al:. Effect of moisture content on some engineering properties of african mahogany (Afzelia africana) seed.
AZOJETE, 15(3):534-553. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com 552

Milani, E., Seyed, M., Razavi, A., Koocheki, A., Nikzadeti, V., Vahedi, N., Moeinfard, M., and
Gholanhosseinpour, A. 2007. Moisture dependent physical properties of curcubit seeds.
International Agrophysics, 21:157-168.
Moshenin, NN. 1986. Physical properties of plant and animal materials. Gordon and Breach press.
New York.
Ndukwu, MC. 2009. Determination of selected physical properties of Brachystegia eurycoma
seeds. Journal of Agricultural Engineering Research, 55:165-169.
Nimkar, PM. and Chattopadhyay, PK. 2001. Some physical properties of green gram. Journal of
Agricultural Engineering Resources, 80(2):183-189.
Ogunjimi, LAO., Aviara, NA. and Aregbesola, OA. 2002. Some engineering properties of locust
bean seed. Journal of Food Engineering, 55:95-99.
Oje, K. 1994. Moisture dependence of some physical properties of cowpea. Ife Journal of
Technology, 4:23-27.
Oje, K. and Ugbor, EC. 1991. Some physical properties of oil bean seed. Journal of Agricultural
Engineering Research, 50:305-313.
Power, PP. 2006. Effects of moisture content on the engineering properties (physical) of Moringa
Africana seeds. B.Eng. University of Maiduguri, Maiduguri, Nigeria.
Sacande, M. 2007. Afzelia Africana. Seed leaflet, (118). Millennium bank seed project. Forest and
Landscape Denmark. 2 pp.
Sacilik, K., Ozturk, R. and Keskin, R. 2002. Some physical properties of thrump seed. Biosystems
Engineering, 86(2):191-198.
Sahoo, PK. and Srivastava, AP. 2002. Physical properties of Okra seed. Biosystems Engineering,
83(4):441-448.
Selvi, KC., Pinar, Y. and Yesilobglu, E. 2006. Some physical properties of linseed.Biosystems
Engineering, 95(4):607-612.
Sessiz, A., Esgici, R. and Kizli, S. 2007. Moisture dependent physical properties of caper (capparis
spp.) fruit. Journal of Food Engineering, 79(4):1426-1431.
Shepherd, H. and Bhardwaj, RK. 1986. Thermal properties of pigeon pea. Cereal Foods World,
31:466-470.
Simonyan, KJ., El-Okene, AM. and Yiljep, YD. 2007. Some physical properties of Samaru sorghum
17.Agricultural Engineering International:The CIGR e-journal, manuscript FP07 008. Vol. IX.
Simonyan, KJ., Yijep, YD., Oyatoyan, OB. and Bawa, GS. 2009. Effects of moisture content on
some physical properties of LabLabpurpureus (L.) seeds. Agricultural Engineering International:
The CIGR ejournal, Manuscript 1279. Vol. XI., July 2009.
Singh, KK. and Goswami, TK. 1999. Thermal properties of cumin seed. Journal of Food
Engineering, 54(4):181-187.
Singh, KK. and Goswami, TK. 1996. Physical properties of cumin seed. Journal of Agricultural
Engineering Research, 64:93-98.
Suthar, SH. and Das, SK. 1996. Some physical properties of Karinga seed. Journal of Agricultural
Engineering Research, 54:219-229.

http://www.azojete.com.ng


Arid Zone Journal of Engineering, Technology and Environment, September, 2019; Vol. 15(3):534-553. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: nddyaviara@yahoo.com

553

Tabatabaeefar, A. 2003. Moisture dependent physical properties of wheat. International
Agrophysics, 17:207-211.
Timbers, GE. 1975. Properties of rapeseed: Thermal conductivity and specific heat. Canadian
Agricultural Engineering, 17:81-84.
Tunde-Akintunde, TY. and Akintunde, BO. 2007. Effect of moisture content and variety on
selected physical properties of beniseed.Agricultural Engineering International: The CIGR
ejournal, Manuscript FP 07 021. Vol. IX.
Yalcin, C. and Ersan, K. 2007. Physical properties of Coriander seeds. Journal of Food Engineering,
80(2):408-416.
Zewdu, A. and Solomon, W. 2008. Moisture dependent physical properties of grass pea (Lathyrus
sativus L.) seeds. Agricultural Engineering International. The CIGR ejournal. Manuscript FP 06 027.
Vol.X

file:///C:/Users/user/Downloads/azojete143/www.azojete.com.ng