item: #1 of 41 id: cord-016897-t71f10kv author: Flores, Marco V. title: Preventing Airborne Disease Transmission: Implications for Patients During Mechanical Ventilation date: 2013-05-29 words: 3664 flesch: 40 summary: Measures to minimize respiratory droplet transmission include using in-line suctioning to maintain the ventilator circuit as a closed system. [ 21 ] systematically reviewed the literature regarding the risk of transmitting acute respiratory infections to HCWs exposed to patients undergoing an AGP compared with the risk of transmission to HCWs caring for patients not undergoing an AGP. keywords: acute; aerosol; airborne; airfl; airway; care; chest; circuit; contact; control; disease; dispersion; dissemination; droplets; generating; hcws; health; high; increase; infection; infl; intubation; large; management; masks; mechanical; n-95; nebulizer; niv; noninvasive; oxygen; particles; patients; physiotherapy; pressure; procedures; protection; respiratory; risk; sars; severe; size; studies; study; syndrome; transmission; uenza; use; ventilation; workers cache: cord-016897-t71f10kv.txt plain text: cord-016897-t71f10kv.txt item: #2 of 41 id: cord-102746-rimpulm0 author: Eaton, W. A. title: Physics of Virus Transmission by Speaking Droplets date: 2020-05-16 words: 2441 flesch: 52 summary: The physics of water droplets is a well-studied subject and its relevance to virus and transmission long known (1-12). While there have been many simulations of droplet evaporation to determine whether droplets containing virions remain floating in air or rapidly fall to the ground, they typically conceal the fundamental mechanisms because of the use of numerics. keywords: air; airborne; droplet; effects; equation; evaporation; fluid; ground; humidity; initial; long; mean; mouth; number; oral; physics; preprint; radii; radius; rate; regime; relative; size; time; transmission; virions; virus; volume; water cache: cord-102746-rimpulm0.txt plain text: cord-102746-rimpulm0.txt item: #3 of 41 id: cord-103945-q3ry13vp author: de Oliveira, P. M. title: Evolution of spray and aerosol from respiratory releases: theoretical estimates for insight on viral transmission date: 2020-07-24 words: 9285 flesch: 50 summary: The well-mixed approximation results in an uniform concentration of suspended viral aerosol droplets that are generated by speaking and reduced via simultaneous ventilation removal, viral inactivation and gravity, similar to Fig. 11(b) . For aerosol droplets in particular, removal by gravity starts only after 20 min with the gravitational settling rate reaching a steady-state value of about 0.39 h −1 (0.13 h −1 for suspended aerosol droplets by coughing) after 30 min. Both viral inactivation and removal by gravity have a small cleansing effect for the aerosols; hence ventilation removal must be added if continuous speaking is to be safe. keywords: aerosol; air; author; available; case; cloud; composition; concentration; considered; copies; copyright; coughing; cov-2; decay; diameter; dose; droplet; effect; emission; emitted; equilibrium; evaporation; evolution; fig; flow; funder; gas; gravity; height; high; holder; hour; humidity; infection; initial; international; jet; july; large; license; liquid; load; magnitude; mass; medrxiv; min; model; nuclei; number; order; perpetuity; preprint; problem; protein; range; relative; removal; respiratory; risk; room; sars; scale; settling; short; size; speaking; speech; sputum; surface; suspended; terms; time; total; transmission; ventilation; version; viable; viral; viral dose; virus; water cache: cord-103945-q3ry13vp.txt plain text: cord-103945-q3ry13vp.txt item: #4 of 41 id: cord-129086-ra2njvcz author: Kumar, Sanjay title: The perspective of fluid flow behavior of respiratory droplets and aerosols through the facemasks in context of SARS-CoV-2 date: 2020-10-10 words: 8131 flesch: 48 summary: While these experimental studies are essential for the broad characterization and design evaluation of respiratory facemasks, further theoretical and numerical methods and algorithm-based investigations provide a better insight into the facemask's fluid flow dynamics and the droplet leakage through the facemask openings. The filtration mechanism of N95 facemasks operates on three possible principles: diffusion, inertial impaction, and electrostatic attraction. keywords: aerosols; air; airborne; airflow; ambient; approach; average; behavior; better; breathing; cloth; coefficient; computational; control; cotton; coughing; covid-19; density; developed; different; diffusion; diseases; dispersion; distance; domain; drag; droplets; dynamics; effective; efficacy; efficiency; equations; et al; evaporation; experimental; facemasks; factors; fig; filter; filtering; filtration; filtration efficiency; flow; flow resistance; fluid; fluid flow; force; gravity; higher; human; humidity; infection; investigations; large; leakage; level; mass; method; model; momentum; mouth; n95; nasal; navier; nose; nostrils; number; pandemic; particles; performance; person; phase; phenomena; potential; pressure; protection; public; rate; recent; research; resistance; respiratory; respiratory droplets; results; saliva; section; simulation; size; small; smaller; source; space; spread; standard; stokes; studies; study; surface; surgical; surgical facemasks; temperature; term; time; transmission; types; use; velocity; virus; virus transmission; volume; wearer; wearing cache: cord-129086-ra2njvcz.txt plain text: cord-129086-ra2njvcz.txt item: #5 of 41 id: cord-148354-3nl3js2x author: Kumar, Vivek title: On the utility of cloth facemasks for controlling ejecta during respiratory events date: 2020-05-05 words: 4628 flesch: 53 summary: Respiratory virus shedding in exhaled breath and efficacy of face masks Potential utilities of mask wearing and instant hand hygiene for SARS-CoV-2 A cluster randomised trial of cloth masks compared with medical masks in healthcare workers Effectiveness of N95 respirators versus surgical masks in protecting health care workers from acute respiratory infection: a systematic review and meta-analysis Covid-19, shortages of masks and the use of cloth masks as a last resort Mass masking in the COVID-19 epidemic: People need guidance Rational use of face masks in the COVID-19 pandemic Not wearing masks to protect against coronavirus is a 'big mistake,' top Chinese scientist says Would everyone wearing face masks help us slow the pandemic? Testing the efficacy of homemade masks: Would they protect in an influenza pandemic? In South East Asian countries, the practice of using face masks for combating pollution or for personal hygiene is widespread. keywords: air; cloth; cloud; computational; cotton; cough; covid-19; distances; distribution; droplets; drops; ejecta; energy; event; experimental; face; face masks; field; figure; floor; flow; fluid; homemade; human; infected; jet; large; mask; mass; model; momentum; openings; particles; patients; penetration; person; phase; resistance; respiratory; results; simple; simulation; size; sneezes; spread; surface; surgical; term; time; transmission; turbulent; use; velocity; virus cache: cord-148354-3nl3js2x.txt plain text: cord-148354-3nl3js2x.txt item: #6 of 41 id: cord-191527-okxzqzl1 author: Gulec, Fatih title: A Molecular Communication Perspective on Airborne Pathogen Transmission and Reception via Droplets Generated by Coughing and Sneezing date: 2020-07-15 words: 6862 flesch: 58 summary: Droplets can be classified as large droplets and droplet nuclei (aerosols) which have sizes of larger and smaller than 10 µm, respectively [24] . The addition with 1 2 within the floor function in (37) quantization by rounding the number of received droplets to the nearest integer. keywords: air; airborne; algorithm; area; axis; buoyancy; cloud; communication; coughing; cross; d k; density; derived; detection; diameter; distance; droplets; end; face; fig; flow; force; gravity; human; infection; initial; laden; macroscale; mass; mean; model; molecular; number; output; paper; pathogen; probability; propagation; proposed; received; reception; results; section; settling; signal; state; step; study; system; time; transmission; values; velocity; volume cache: cord-191527-okxzqzl1.txt plain text: cord-191527-okxzqzl1.txt item: #7 of 41 id: cord-208426-wz3jan5d author: Li, Hongying title: Airborne dispersion of droplets during coughing: a physical model of viral transmission date: 2020-08-05 words: 4497 flesch: 48 summary: In a recent study based on turbulent cloud physics, cough droplets are reported to spread up to 7-8 m. 20 Further, researchers at Wuhan hospitals found corona-virus residues in floor samples up to 4 m from identified sources. Young children may be at greater risk from droplet transmission compared to adults ( Figure 1 ). keywords: airborne; body; case; conditions; copies; coronavirus; cough; cougher; count; cov-2; covid-19; deposition; dispersion; distance; distancing; distribution; dose; droplet; energy; evaporation; face; figure; flow; humidity; infection; jet; large; listener; load; median; model; non; nuclei; number; person; plume; potential; probability; range; respiratory; results; risk; sars; significant; size; small; social; speed; study; supplementary; surface; time; transmission; viral; viruses; wind cache: cord-208426-wz3jan5d.txt plain text: cord-208426-wz3jan5d.txt item: #8 of 41 id: cord-253252-s8fm5rfa author: Jayaweera, Mahesh title: Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy date: 2020-06-13 words: 14122 flesch: 36 summary: With the onset of the COVID-19 pandemic, many researchers have been in the development of effective filtering mechanisms to combat SARS-CoV-2-laden aerosol transmission; however, until early May 2020, there have been no promising PPE developed to curtail such transmission. Morawska (2006) has presented a classification for virus transmission, including human-human transmission, airborne transmission, and other means of transmission such as endogenous infection, common vehicle, and vector spread. keywords: ach; acute; aerosol transmission; aerosols; agents; air; airborne; airborne transmission; airflow; behavior; cabin; cases; china; cloud; conditions; confined; contact; control; coronavirus; cough; countries; cov-2; covid-19; different; disease; distance; droplets; effects; environmental; et al; evidence; exposure; fact; factors; far; figure; fomites; greater; guidelines; healthcare; high; host; hour; human; humidity; inactivation; indoor; infected; infection; influenza; jet; laden; larger; lower; masks; medical; minimum; modes; morawska; movement; n95; nosocomial; nuclei; open; organization; pandemic; paper; particles; passenger; patient; people; periods; person; personal; phenomena; plume; positive; potential; prevention; range; relative; relative humidity; respiratory; review; risk; role; room; sars; seat; settings; severe; significant; similar; size; smaller; source; spaces; spread; studies; study; sunlight; surfaces; surgical; survival; susceptible; symptomatic; syndrome; temperature; transmission; transport; van; vehicle; ventilation; viability; viral; virus; viruses; windows; workers; world cache: cord-253252-s8fm5rfa.txt plain text: cord-253252-s8fm5rfa.txt item: #9 of 41 id: cord-254894-ta7hebbg author: Balachandar, S. title: Host-to-Host Airborne Transmission As a Multiphase Flow Problem For Science-Based Social Distance Guidelines date: 2020-09-04 words: 17087 flesch: 51 summary: Smaller droplets ( O(100 µm)) that remain suspended within the puff are advected forward. Other less violent processes could lead to the formation of small droplets such as the breakup of small films and menisci described in [77] without going through the sequence of events described above. keywords: aerosol; air; airborne; airborne droplets; ambient; analysis; approach; aspiration; atomization; breakup; breathing; buoyancy; case; clear; cloud; coefficient; concentration; conditions; coughing; current; d e; data; decreases; density; deposition; diameter; different; dispersion; distance; distribution; drag; droplet; droplet cloud; droplet diameter; droplet evaporation; droplet nuclei; droplet size; droplet temperature; droplet velocity; drops; dynamics; effect; efficiency; ejection; entrainment; evaporated; evaporation; evolution; example; exhalation; exit; experimental; fall; figure; filtration; final; flow; fluid; following; formation; fraction; framework; function; gas; generation; guidelines; high; host; human; important; increases; inhalability; inhaled; initial; initial droplet; initial puff; laden; laden droplets; larger; late; lim; log; lower; masks; matter; model; momentum; motion; n95; nasal; non; normal; number; numerical; order; pareto; particles; present; processes; puff; puff model; puff velocity; range; rate; receiving; respiratory; respiratory droplets; results; reynolds; role; route; s e; scale; section; settling; simple; size distribution; sizes; smaller; smaller droplets; specific; speed; stage; studies; surgical; surrounding; t e; t lim; temperature; terms; thermal; time; time t; total; transmission; transport; turbulent; upper; use; value; velocity; vertical; virus; viruses; volatile; volume; water cache: cord-254894-ta7hebbg.txt plain text: cord-254894-ta7hebbg.txt item: #10 of 41 id: cord-255084-qav7yb0p author: Li, Xiangdong title: Modelling of evaporation of cough droplets in inhomogeneous humidity fields using the multi-component Eulerian-Lagrangian approach date: 2018-01-15 words: 5900 flesch: 49 summary: The approach is featured with a continuity equation being explicitly solved for water vapor, which allows comprehensively considering the effects of inhomogeneous humidity field on droplets evaporation and movement. S v is the mass source of water vapor due to droplets evaporation. keywords: air; airborne; airborne droplets; ambient; approach; case; computations; concentration; conditions; cough; density; dependent; diameter; different; dispersion; droplet evaporation; droplet mass; droplets; effects; equilibrium; evaporation; exhaled; field; fig; fraction; human; humidity; infection; inhalable; inhomogeneous; inhomogeneous humidity; larger; mass; median; mixture; model; nuclei; number; plume; pressure; rate; relative; respiratory; results; risks; size; smaller; study; temperature; time; trajectories; transport; vapor; vapor concentration; velocity; water; water vapor; yes; μm droplets cache: cord-255084-qav7yb0p.txt plain text: cord-255084-qav7yb0p.txt item: #11 of 41 id: cord-255770-gbhjke93 author: Meccariello, Giuseppe title: What ENT doctors should know about COVID‐19 contagion risks date: 2020-04-24 words: 823 flesch: 40 summary: Furthermore, the size of sneezing droplets is 341.5 to 398.1 μm for unimodal distribution and 73.6 to 85.8 μm for bimodal distribution. The final equilibrium diameter of expiratory droplets after evaporation is highly dependent upon the temperature and relative humidity of the environment. keywords: airflow; asymptomatic; contact; contagion; cough; covid-19; droplets; environment; high; milliseconds; number; patients; procedures; respiratory; sneeze; sneezing; viral cache: cord-255770-gbhjke93.txt plain text: cord-255770-gbhjke93.txt item: #12 of 41 id: cord-258304-86gqxajw author: Bahl, Prateek title: Droplets and Aerosols generated by singing and the risk of COVID-19 for choirs date: 2020-09-18 words: 1554 flesch: 49 summary: To capture the video, the head of the subject was adjusted in front of black backdrop/background and the light was positioned in a forward scatter arrangement to maximize the scattering from expelled droplets ( Figure 1 ). While social distancing is effective in normal social interactions, singing can produce a substantially larger number of respiratory droplets and aerosols than speaking, as it is louder and sustained for longer durations keywords: aerosols; airborne; covid-19; direction; droplets; figure; flow; greater; high; infection; mouth; outbreaks; particle; respiratory; results; risk; singing; size; spread; subject; tracking; transmission; velocimetry; velocities; video cache: cord-258304-86gqxajw.txt plain text: cord-258304-86gqxajw.txt item: #13 of 41 id: cord-263644-rg00br0d author: Lai, A. C. K. title: Emission strength of airborne pathogens during toilet flushing date: 2017-08-14 words: 3934 flesch: 46 summary: All public housing in Hong Kong, which accommodates ~30% of the approximately 7.3 million population, is equipped with such toilets. The pathogens emitted by the first flush were calculated, with the correlations between airborne pathogen emissions and droplet concentration (HP, r=0.944, P<.001; LP, r=0.803, P<.001, HT, r=0.885, P<.05) and bacterial size (HP, r=−0.919, P<.001; LP, r=−0.936, P<.001; HT, r=−0.967, P<.05) in the different conditions then tested. keywords: aerosols; airborne; bacterial; bowl; box; buildings; cistern; cistern tank; concentration; conditions; contaminated; correlation; counter; diameter; different; drainage; droplet; emission; emission strength; experiments; figure; flushing; flushometer; height; high; important; infectious; kpa; level; low; parameters; particle; pathogens; pressure; process; range; results; risk; sampling; scenarios; seat; size; small; strength; study; surface; systems; table; tank; toilet; transmission; water cache: cord-263644-rg00br0d.txt plain text: cord-263644-rg00br0d.txt item: #14 of 41 id: cord-271822-ohkki0ke author: Verma, Siddhartha title: Visualizing the effectiveness of face masks in obstructing respiratory jets date: 2020-06-01 words: 3258 flesch: 41 summary: Steps of fluid fragmentation leading to respiratory droplets The efficacy of standard surgical face masks: An investigation using tracer particles A quantitative assessment of the efficacy of surgical and N95 masks to filter influenza virus in patients with acute influenza infection Dispersion and exposure to a cough-generated aerosol in a simulated medical examination room Efficacy of face shields against cough aerosol droplets from a cough simulator Effectiveness of cough etiquette maneuvers in disrupting the chain of transmission of infectious respiratory diseases Respiratory virus shedding in exhaled breath and efficacy of face masks Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses Simple respiratory protection-Evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles Testing the efficacy of homemade masks: Would they protect in an influenza pandemic? Effectiveness of surgical and cotton masks in blocking SARS-CoV-2: A controlled comparison in 4 patients Aerosol filtration efficiency of common fabrics used in respiratory cloth masks Rational use of face masks in the COVID-19 pandemic Nonpharmaceutical measures for pandemic influenza in nonhealthcare settings-personal protective and environmental measures Flow dynamics and characterization of a cough Coughing frequency in patients with persistent cough: The masks help mitigate the risk of cross-infection via respiratory droplets; however, there are no specific guidelines on mask materials and designs that are most effective in minimizing droplet dispersal. keywords: aerosol; air; airborne; control; cough; coughing; covid-19; cross; current; diameter; disease; dispersal; distance; droplets; effective; effectiveness; efficacy; equipment; face; face masks; fig; forward; healthcare; high; individuals; infected; infection; influenza; jet; jets; leakage; masks; material; medical; nuclei; pandemic; particles; pathogens; protective; public; respiratory; respiratory droplets; size; smallest; stopping; studies; study; tracer; transmission; use; visualization cache: cord-271822-ohkki0ke.txt plain text: cord-271822-ohkki0ke.txt item: #15 of 41 id: cord-274083-6vln3erl author: Bhardwaj, Rajneesh title: Likelihood of survival of coronavirus in a respiratory droplet deposited on a solid surface date: 2020-06-01 words: 3527 flesch: 53 summary: Liu et al. 2 reported around 20% longer drying time of saliva droplets as compared to water droplets deposited on a Teflonprinted slide. They reported that large droplets expelled horizontally can travel a long distance before hitting the ground. keywords: air; ambient; angle; cities; contact; covid-19; diameter; different; distribution; droplet; effect; evaporation; evaporation time; fig; flow; growth; humidity; increase; large; mean; model; present; range; rate; relative; respiratory; sessile; shear; stress; surface; survival; temperature; time; virus; volume; water cache: cord-274083-6vln3erl.txt plain text: cord-274083-6vln3erl.txt item: #16 of 41 id: cord-274781-tmc31aa6 author: Cummins, C. P. title: The dispersion of spherical droplets in source–sink flows and their relevance to the COVID-19 pandemic date: 2020-08-01 words: 6365 flesch: 54 summary: We find that, in the absence of gravity, there are two distinct behaviors for the droplets: small droplets cannot go further than a specific distance, which we determine analytically, from the source before getting pulled into the sink. Gravitational effects are considered for small droplets in Sec. keywords: absence; aerosol; air; airborne; airflow; ballistic; basset; breathing; case; circle; coughing; density; diameter; dispersion; distance; drag; droplets; dynamics; effects; emitted; equation; extraction; fig; fixed; flow; fluid; force; gravitational; gravity; history; horizontal; human; inequality; inertia; intermediate; jet; large; maxey; maximum; model; non; order; origin; paper; particles; point; range; respiratory; riley; sec; sink; size; small; small droplets; source; speed; studies; term; time; trajectories; trajectory; transmission; unit; velocity; virus cache: cord-274781-tmc31aa6.txt plain text: cord-274781-tmc31aa6.txt item: #17 of 41 id: cord-275303-8mj8gjv9 author: Chaudhuri, Swetaprovo title: Modeling the role of respiratory droplets in Covid-19 type pandemics date: 2020-06-01 words: 8014 flesch: 54 summary: key: cord-275303-8mj8gjv9 authors: Chaudhuri, Swetaprovo; Basu, Saptarshi; Kabi, Prasenjit; Unni, Vishnu R.; Saha, Abhishek title: Modeling the role of respiratory droplets in Covid-19 type pandemics date: 2020-06-01 journal: Phys Fluids (1994) DOI: 10.1063/5.0015984 sha: doc_id: 275303 cord_uid: 8mj8gjv9 In this paper, we develop a first principles model that connects respiratory droplet physics with the evolution of a pandemic such as the ongoing Covid-19. The multi-scale model thus developed and the firm theoretical underpinning that connects the two scales—macro-scale pandemic dynamics and micro-scale droplet physics—thus could emerge as a powerful tool in elucidating the role of environmental factors on infection spread through respiratory droplets. keywords: 1,s; air; ambient; average; case; cloud; collision; concentration; conditions; constant; contact; coughing; covid-19; crystallization; dcrit; diameter; droplet; droplet cloud; droplet evaporation; droplet lifetime; droplet surface; dynamics; equations; evaporation; evolution; experiments; fig; fraction; function; growth; healthy; heat; high; humidity; infection; initial; jet; kinetics; large; lifetime; liquid; low; mass; mechanism; model; modeling; number; pandemic; paper; person; present; puff; range; rate; reaction; relative; respiratory; respiratory droplets; results; rh∞; salt; settling; size; smaller; solute; solution; spread; surface; temperature; time; total; transfer; transmission; turbulent; vdh; velocity; virus; volume; water cache: cord-275303-8mj8gjv9.txt plain text: cord-275303-8mj8gjv9.txt item: #18 of 41 id: cord-276649-3zl3pm79 author: Tan, Vanessa Y. J. title: Respiratory droplet generation and dispersal during nasoendoscopy and upper respiratory swab testing date: 2020-07-04 words: 1098 flesch: 43 summary: The sagittal plane dispersal patterns of respiratory droplets were captured using a digital camera (Panasonic Lumix GH4) at 60 frames per second in a low-airflow light-controlled laboratory. We outline the following recommendations: pull the face mask down partially and keep the mouth covered, only allowing nasal access during nasoendoscopy; avoid nasal sprays if possible; if nasal sprays are used, procedurists should be in full personal protective equipment prior to using the spray; withdrawal of swabs and scopes should be performed in a slow and controlled fashion to reduce potential dispersion of droplets when the capillary bridge of mucus breaks up. keywords: aerosol; bridge; capillary; covid-19; decongestion; dispersal; droplet; equipment; formation; generation; mucus; nasal; nasoendoscopy; nasopharyngeal; recommendations; respiratory; spray; swab; testing; video cache: cord-276649-3zl3pm79.txt plain text: cord-276649-3zl3pm79.txt item: #19 of 41 id: cord-290277-ndfoppoq author: Bahl, Prateek title: Airborne or droplet precautions for health workers treating COVID-19? date: 2020-04-16 words: 3498 flesch: 52 summary: Management of ill travellers at points of entryinternational airports, seaports and ground crossings -in the context of COVID-19 outbreak: interim guidance World Health Organization Cluster randomised controlled trial to examine medical mask use as source control for people with respiratory illness Interim Healthcare Infection Prevention and Control Recommendations for Patients Under Investigation for 2019 Novel Coronavirus Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement Study on transport characteristics of saliva droplets calm indoor environment How far droplets can move in indoor environments -revisiting the Wells evaporation-falling curve Theoretical analysis of the motion and evaporation of exhaled respiratory droplets of mixed composition Violent expiratory events: On coughing and sneezing Enhanced spread of expiratory droplets by turbulence in a cough jet Evaporation and dispersion of respiratory droplets from coughing. A systematic review was conducted for evidence of horizontal distance travelled by respiratory droplets, using the PRISMA criteria keywords: airborne; care; cases; cloud; control; coronavirus; cov-2; covid-19; distance; droplet; evaporation; evidence; guidelines; hcws; health; horizontal; hospital; human; infection; interim; limit; organization; patients; precautions; prevention; range; respiratory; review; risk; sars; separation; severe; spatial; spread; studies; study; syndrome; transmission; use; workers; world cache: cord-290277-ndfoppoq.txt plain text: cord-290277-ndfoppoq.txt item: #20 of 41 id: cord-291836-dlsas702 author: Yang, Xia title: Transmission of pathogen-laden expiratory droplets in a coach bus date: 2020-04-12 words: 4856 flesch: 52 summary: The relative humidity brings the same function to droplets size. Then the impacts of RH, initial droplet diameters and air-conditioning supply directions can be investigated as case studies by CFD simulations. keywords: 10μm; air; airborne; airflow; body; bus; cfd; coach; concentration; condition; deposit; diameter; different; diffusion; direction; diseases; dispersion; droplets; effect; environments; evaporation; exhaust; fig; force; gravity; high; human; humidity; indoor; infection; influence; initial; isolation; larger; model; number; numerical; particle; passengers; patient; process; relative; respiratory; risk; room; simulation; size; solid; source; studies; study; supply; surfaces; time; transmission; transport; ventilation; wind; μm droplets cache: cord-291836-dlsas702.txt plain text: cord-291836-dlsas702.txt item: #21 of 41 id: cord-293097-poh1y6o7 author: V, Antony Aroul Raj title: The contribution of dry indoor built environment on the spread of Coronavirus: Data from various Indian states date: 2020-07-02 words: 3075 flesch: 48 summary: The rationale for such a policy is that virus transmission occurs through direct contact and droplet transmission, and public health professionals believe that using facial masks and gloves is an efficient way in preventing virus spread. Understanding the mechanism of production of dry pockets in various indoor air environments by the heating, ventilating and air conditioning (HVAC) systems is very essential to take appropriate measures and to reduce the rate of transmission. keywords: active; air; available; cold; conditions; coronavirus; data; density; droplet; dry; drying; effect; environment; heat; heating; high; hot; humidity; hvac; indoor; indoor environment; infection; low; major; mass; person; population; potential; present; rate; relative; respiratory; size; spread; states; system; temperature; transfer; transmission; virus; zone cache: cord-293097-poh1y6o7.txt plain text: cord-293097-poh1y6o7.txt item: #22 of 41 id: cord-298227-av1ev8ta author: Kähler, Christian J. title: Fundamental protective mechanisms of face masks against droplet infections date: 2020-06-28 words: 7150 flesch: 52 summary: key: cord-298227-av1ev8ta authors: Kähler, Christian J.; Hain, Rainer title: Fundamental protective mechanisms of face masks against droplet infections date: 2020-06-28 journal: J Aerosol Sci DOI: 10.1016/j.jaerosci.2020.105617 sha: doc_id: 298227 cord_uid: av1ev8ta Many governments have instructed the population to wear simple mouth-and-nose covers or surgical face masks to protect themselves from droplet infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in public. It was surprizing that for months, WHO, the CDC and many public health professionals in Europe advised against wearing face masks unless someone has COVID-19 or cares for someone who has COVID-19 (Feng et al., 2020 and Leung et al., 2020a) . keywords: aerosol; air; breathing; contaminated; coughing; cov-2; covers; covid-19; diameter; distance; droplet infection; droplets; effect; effective; effectiveness; environment; et al; face; face masks; fig; filter material; filtering; flow; fundamental; germany; good; hygiene; important; infected; infection; large; light; long; masks; material; medical; mouth; movement; nose; pandemic; particle; patients; people; person; population; pressure; properties; protection; public; rate; resistance; respiratory; results; risk; rules; sars; second; section; self; severe; sheet; shows; simple; singing; small; spread; sufficient; surgical; surgical mask; system; tested; time; transmission; use; velocity; virus; viruses; volume; wearing cache: cord-298227-av1ev8ta.txt plain text: cord-298227-av1ev8ta.txt item: #23 of 41 id: cord-298461-tyhtdawb author: Zhao, L. title: COVID-19: Effects of weather conditions on the propagation of respiratory droplets date: 2020-05-25 words: 7836 flesch: 48 summary: The transmitting pathway of COVID-19 through respiratory droplets is divided into short-range droplet contacts and long-range aerosol exposure. The transmitting pathway of COVID-19 through respiratory droplets is divided into short-range droplet contacts and long-range aerosol exposure. keywords: aerosol; aerosol particles; air; author; brownian; conditions; contact; copyright; cov-2; covid-19; diameter; different; disease; distance; distancing; doi; droplet; dry; effect; environment; evaporation; figure; funder; gravity; health; heat; high; holder; hot; https://doi.org/10.1101/2020.05.24.20111963; humidity; initial; license; mass; medrxiv; medrxiv preprint; model; nuclei; number; particles; peer; permission; perpetuity; pm2.5; preprint; range; respiratory; respiratory droplets; reuse; review; rights; sars; size; smaller; social; study; summer; temperature; time; transmission; velocity; ventilation; version; virus; weather; weather conditions; wind cache: cord-298461-tyhtdawb.txt plain text: cord-298461-tyhtdawb.txt item: #24 of 41 id: cord-301721-31a2q3ad author: Balachandar, S. title: Host-to-Host Airborne Transmission As a Multiphase Flow Problem For Science-Based Social Distance Guidelines date: 2020-09-01 words: 16803 flesch: 52 summary: Smaller droplets ( O(100 µm)) that remain suspended within the puff are advected forward. Other less violent processes could lead to the formation of small droplets such as the breakup of small films and menisci described in [72] without going through the sequence of events described above. keywords: aerosol; air; airborne; airborne droplets; ambient; analysis; approach; aspiration; atomization; author; available; breakup; breathing; buoyancy; case; clear; cloud; coefficient; concentration; copyright; coughing; d e; data; decreases; density; deposition; diameter; different; dispersion; distance; distribution; doi; drag; droplet; droplet cloud; droplet diameter; droplet nuclei; droplet size; droplet velocity; drops; dynamics; effect; efficiency; ejection; entrainment; evaporated; evaporation; evolution; exhalation; exit; experimental; fall; figure; final; flow; fluid; following; formation; fraction; framework; funder; gas; high; holder; host; human; important; inhalability; inhaled; initial; initial droplet; international; laden; laden droplets; larger; late; license; lim; log; masks; matter; medrxiv; medrxiv preprint; model; momentum; motion; n95; non; normal; number; numerical; pareto; particles; peer; perpetuity; preprint; processes; puff; puff model; puff velocity; range; rate; respiratory; respiratory droplets; results; review; role; scale; section; september; settling; simple; size; size distribution; small; smaller; speed; stage; studies; surrounding; t e; t lim; temperature; terms; thermal; time; time t; total; transmission; transport; turbulent; upper; value; velocity; version; virus; volatile; volume; water cache: cord-301721-31a2q3ad.txt plain text: cord-301721-31a2q3ad.txt item: #25 of 41 id: cord-306861-qcctchsk author: Chen, Xiaole title: Modeling of the transport, hygroscopic growth, and deposition of multi-component droplets in a simplified airway with realistic thermal boundary conditions date: 2020-07-24 words: 3312 flesch: 50 summary: 1.786×10 -5 On the effect of anisotropy on the turbulent dispersion 13 and deposition of small particles Evaporation and movement of fine droplets in non-uniform temperature and 16 humidity field A numerical study of heat 18 and water vapor transfer in mdct-based human airway models Numerical 21 investigation of motion of sulfuric and hydrochloric droplets with phase 22 change in free-falling process Airflow and deposition of nano-particles in a human nasal 25 cavity Experimental measurement and 27 numerical study of particle deposition in highly idealized mouth-throat models Particle deposition measurements and 30 numerical simulation in a highly idealized mouth-throat Transient airflow structures and particle 33 transport in a sequentially branching lung airway model Species heat and mass transfer in a human upper 36 airway model Cyclic micron-size particle inhalation 38 and deposition in a triple bifurcation lung airway model Slip correction measurements of spherical solid 7 aerosol particles in an improved Millikan apparatus Numerical investigation of 10 the interaction, transport and deposition of multicomponent droplets in a 11 simple mouth-throat model Effects of thermal 13 airflow and mucus-layer interaction on hygroscopic droplet deposition in a 14 simple mouth-throat model Study on gas/solid flow in 16 an obstructed pulmonary airway with transient flow based on CFD-DPM Sci Improved numerical simulation 12 of aerosol deposition in an idealized mouth-throat An investigation of particle trajectories in 14 two-phase flow systems Size-change and deposition of 16 conventional and composite cigarette smoke particles during inhalation in a 17 subject-specific airway model Cyclic micron-size particle inhalation 19 and deposition in a triple bifurcation lung airway model ρ is the droplet/particle density. The difference between our 19 predictions and the experimental results (W. Li et al., 1992) for the hygroscopic growth 20 of NaCl particle is only ± 0.2 % RH (or ± 0.4 in growth ratio) (Chen, et al., 2017) . keywords: airflow; airway; boundary; chen; component; condition; deposition; distributions; droplet; et al; evaporation; figure; flow; growth; heat; higher; hygroscopic; inhalation; interaction; latent; layer; mass; model; mucus; numerical; particle; rate; realistic; region; study; temperature; thermal; tissue; tissue layer; transfer; transport; vapor; water cache: cord-306861-qcctchsk.txt plain text: cord-306861-qcctchsk.txt item: #26 of 41 id: cord-307264-l13gyl94 author: Netz, Roland R. title: Physics of virus transmission by speaking droplets date: 2020-10-13 words: 2183 flesch: 50 summary: COVID-19 | virus transmission | speaking droplets | SARS-CoV-2 T he physics of water droplets is a well-studied subject, and its relevance to virus transmission is long known (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) . key: cord-307264-l13gyl94 authors: Netz, Roland R.; Eaton, William A. title: Physics of virus transmission by speaking droplets date: 2020-10-13 journal: Proc Natl Acad Sci U S A DOI: 10.1073/pnas.2011889117 sha: doc_id: 307264 cord_uid: l13gyl94 To make the physics of person-to-person virus transmission from emitted droplets of oral fluid while speaking easily understood, we present simple and transparent algebraic equations that capture the essential physics of the problem. keywords: airborne; droplet; equations; evaporation; fall; ground; humidity; initial; min; nuclei; person; physics; radii; radius; relative; sed; size; speaking; times; transmission; virions; virus; water cache: cord-307264-l13gyl94.txt plain text: cord-307264-l13gyl94.txt item: #27 of 41 id: cord-307768-xx46w6dc author: Ding, Yun title: From single-molecule detection to next-generation sequencing: microfluidic droplets for high-throughput nucleic acid analysis date: 2017-03-10 words: 9495 flesch: 32 summary: Common actuating sources for such purposes include pneumatic pressure (Unger et al. 2000; Willaime et al. 2006; Zeng et al. 2009 ), mechanical forces , electrical fields (Link et al. 2006) , magnetic fields (Vekselman et al. 2015) , acoustic waves (Collins et al. 2013) , optical traps (Lorenz et al. 2006 ) and thermal gradients (Baroud et al. 2007) . Droplet surface area is nearly minimised by producing spherical ends (Baroud et al. 2010) keywords: ability; accurate; acid; amplification; analysis; applications; approach; aqueous; assays; barcode; beads; biological; cancer; cell; centrifugal; chain; chamber; channel; chemical; chip; complex; components; continuous; control; copyright; cost; critical; current; cycling; data; ddpcr; demand; detection; developments; device; digital; dna; droplet; effect; efficient; egfr; emulsion; encapsulation; et al; example; experimentation; experiments; expression; fashion; fig; flow; formation; formats; fragments; free; functional; gel; generation; genetic; genome; griffiths; gruner; high; hydrogel; immiscible; important; incubation; individual; inlet; integrated; interface; isothermal; key; lamp; large; level; long; loop; magnetic; manner; merging; methods; microfluidic; microparticles; millions; molecular; molecule; multiple; mutations; new; ngs; novel; nucleic; number; oil; oils; operations; packed; pairing; parallel; partitioning; passive; pcr; permission; phase; platform; point; polymerase; pressure; production; quantitative; range; rapid; rare; reaction; read; reagent; recent; ref; respect; reverse; rna; robust; sample; scale; screening; sequencing; short; significant; single; size; small; sorting; standard; step; surface; systems; target; technologies; template; term; throughput; time; timescales; transport; ultra; unique; use; utility; volume; wide; workflows cache: cord-307768-xx46w6dc.txt plain text: cord-307768-xx46w6dc.txt item: #28 of 41 id: cord-312236-8eaqn8eu author: Lai, Alvin C.K. title: Study of expiratory droplet dispersion and transport using a new Eulerian modeling approach date: 2007-06-02 words: 4112 flesch: 50 summary: Particle relaxation time (t) is used to characterize the time required for the particle to 'relax' to become airborne where C c is Cunningham slip correction factor, d p is the droplet diameter, and m is the kinematics viscosity of air. Aerosol droplet dispersion and transport in a ventilated enclosure depend on the ventilation scheme, particle size, density, concentration, source location, etc. keywords: aerosol; airborne; airflow; approach; characteristics; coarse; concentration; density; different; dispersion; displacement; displacement ventilation; drift; droplet; droplet nuclei; et al; eulerian; exposure; fig; flux; gaseous; gravitational; high; indoor; lagrangian; lai; methodology; mid; mixed; model; new; nicas; nuclei; number; occupant; particle; pattern; phase; plane; present; receptor; region; results; room; scheme; settling; simulation; size; source; study; time; transmission; transport; velocity; ventilation; wall cache: cord-312236-8eaqn8eu.txt plain text: cord-312236-8eaqn8eu.txt item: #29 of 41 id: cord-312708-9ywu6r2t author: Sharma, Dhruv title: Cadaveric Simulation of Otologic Procedures: An Analysis of Droplet Splatter Patterns During the COVID-19 Pandemic date: 2020-05-19 words: 2230 flesch: 42 summary: With the persistence of SARS-CoV-2 in the general population for the foreseeable future, we will need to navigate these risks as we resume elective surgical procedures and perform urgent operations on patients whose SARS-CoV-2 status is unknown or positive. Coronavirus disease 2019 (COVID-19) situation report-100 Bloodcontaining aerosols generated by surgical techniques: a possible infectious hazard A simple technique for droplet control during mastoid surgery Competing interests: None. Funding source: None. keywords: aerosolization; contamination; covid-19; drafting; drill; droplet; ear; editing; final; fluorescein; generation; gross; head; left; manuscript; mastoidectomy; measured; middle; myringotomy; otologic; procedures; respiratory; risk; sars; sign; splatter; spread; study; surgeon; surgical; transmission; tube; ventilation; viral cache: cord-312708-9ywu6r2t.txt plain text: cord-312708-9ywu6r2t.txt item: #30 of 41 id: cord-313636-kcjnjq52 author: Kusunose, Kenya title: Identifying the extent of oral fluid droplets on echocardiographic machine consoles in COVID-19 era date: 2020-09-18 words: 1019 flesch: 49 summary: The main findings of this study were (1) many droplets were spread by speech, with the front right side of the console particularly contaminated; (2) there was no significant difference for the count of droplets between English and Japanese; (3) mask usage can significantly cut down droplet spreading by speech. The recent study showed that the th sound in the word healthy was a significant generator of speech droplets keywords: console; covid-19; droplets; echocardiographic; english; extent; important; japanese; machine; masks; observers; patient; risk; significant; speech; spread; study; surgical cache: cord-313636-kcjnjq52.txt plain text: cord-313636-kcjnjq52.txt item: #31 of 41 id: cord-315130-8g2ih8zl author: Bax, Adriaan title: SARS-CoV-2 transmission via speech-generated respiratory droplets date: 2020-09-11 words: 1838 flesch: 46 summary: Surfing the COVID-19 scientific wave The size and the duration of air-carriage of respiratory droplets and dropletnuclei On air-borne infection -Study II Droplets and droplet nuclei Guidelines for Environmental Infection Control in Health-Care Facilities Indoor air humidity, air quality, and health -An overview Mechanisms of airborne infection via evaporating and sedimenting droplets produced by speaking The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission What Noises Cause Hearing Loss Visualizing Speech-Generated Oral Fluid Droplets with Laser Light Scattering Virological assessment of hospitalized patients with COVID-2019 Investigation of a COVID-19 outbreak in Germany resulting from a single travel-associated primary case: a case series A schlieren optical study of the human cough with and without wearing masks for aerosol infection control Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2) WHO confirms there's 'emerging evidence' of airborne transmission of The role of particle size in aerosolised pathogen transmission: A review SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients Viral RNA Load in Mildly Symptomatic and Asymptomatic Children with COVID-19 Temporal dynamics in viral shedding and transmissibility of COVID-19 Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study Physiology of airway mucus clearance Modality of human expired aerosol size distributions Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities For example, we could have stated an average of 17 virions per second over a period of 25 seconds but such a number would suggest a precision higher than warranted, considering the wide variation in viral load and the fractional uncertainty in the diameter of the fully hydrated particles. keywords: air; airborne; asymptomatic; authors; covid-19; disease; droplets; fan; figure; green; high; infection; light; load; oropharyngeal; particles; patients; report; respiratory; results; sars; speech; study; symptoms; time; transmission; viral; virions; wolfel cache: cord-315130-8g2ih8zl.txt plain text: cord-315130-8g2ih8zl.txt item: #32 of 41 id: cord-316129-mjg3un0l author: Khamar, Pooja title: Aerosol and droplet creation during oscillatory motion of the microkeratome amidst COVID-19 and other infectious diseases date: 2020-07-13 words: 3677 flesch: 54 summary: 5 Airborne transmission of a disease is defined as the transmission of infection by large droplets over short distances or through aerosols (smaller droplets) over large distances. Statista Aerosol delivery using jet nebulizer and vibrating mesh nebulizer during high frequency oscillatory ventilation: an in vitro comparison Images in clinical medicine: coughing and masks A schlieren optical study of the human cough with and without wearing masks for aerosol infection control Alert up-date: coronavirus (COVID-2019) and ocular tissue donation Goat's eye integrated with a human cataractous lens: a training model for phacoemulsification Unsteady turbulent round jets and vortex motion Boundary Layer Theory Fluid Dynamics and Transport of Droplets and Sprays Aerosol generated procedure in intraocular surgery Aerosol during phaco (cataract surgery): how to make cataract surgery safe during Covid-19 Handbook of Experimental Fluid Mechanics The role of particle size in aerosolised pathogen transmission: a review Analysis of droplet clustering in air-assist sprays using Voronoi tessellations Modeling the role of respiratory droplets in Covid-19 type pandemics Toward understanding the risk of secondary airborne infection: emission of respirable pathogens Do intact viral particles survive excimer laser ablation? keywords: advancement; aerosols; air; airflow; atomization; balanced; camera; constant; corneal; coronavirus; cov-2; covid-19; creation; diameter; direction; distance; distribution; droplet; eye; figure; flap; flap creation; goat; high; jet; lasik; lens; microkeratome; operating; patients; refractive; risk; salt; sars; shadowgraphy; size; smaller; solution; speed; spread; study; surface; surgery; surgical; theater; transmission; velocity; viral; virus cache: cord-316129-mjg3un0l.txt plain text: cord-316129-mjg3un0l.txt item: #33 of 41 id: cord-318187-c59c9vi3 author: Basu, Saikat title: Numerical evaluation of spray position for improved nasal drug delivery date: 2020-06-29 words: 7860 flesch: 37 summary: This project has generated both simulated and experimental, quantitative, de-identified data on the regional deposition of aerosolized nasal medication in the form of nasal spray droplets in the sinonasal passages. In this study, we have identified a new usage strategy for nasal sprays available over-the-counter, that registers an average 8-fold improvement in topical delivery of drugs at diseased sites, when compared to prevalent spray techniques. keywords: airflow; airspace; airway; analysis; anatomic; anterior; average; axis; best; breathing; cavity; cfd; chronic; clinical; columns; comparison; computational; coronavirus; correlation; corresponding; current; data; delivery; deposition; deposits; different; digital; directions; distribution; droplet; droplet transport; drug; drug delivery; dynamics; effect; experimental; fig; findings; fluid; gamma; human; image; inertial; inhalation; inhaled; intra; los; mass; measurements; models; motion; nasal; nasal airflow; nasal spray; nose; nostril; note; npm1; numerical; omc; paired; panel; parameters; passage; patient; percentage; perturbed; physical; plane; points; predictions; pressure; protocol; range; rank; reference; respiratory; rhinosinusitis; sagittal; scintigraphy; shot; signals; silico; simulated; simulations; sinonasal; sinuses; sites; size; solid; solution; specific; spray; sprayed; strategy; study; subject; table; target; techniques; test; topical; transport; true; tspd; usage; use; value; velocity; walls; www.nature.com/scientificreports cache: cord-318187-c59c9vi3.txt plain text: cord-318187-c59c9vi3.txt item: #34 of 41 id: cord-318835-sd9hbocg author: Felfeli, Tina title: Utility of patient face masks to limit droplet spread from simulated coughs at the slit lamp date: 2020-07-27 words: 1706 flesch: 50 summary: Of major concern are the high titres of virus in the oropharynx early in the disease course, and long incubation period (5À7 days) of asymptomatic shedding of severe acute respiratory syndrome coronavirus 2. 1 Effective use of personal protective equipment (PPE) such as gloves, face masks, goggles, face shields, and gowns is critical to prevent the spread of infection to and from health care workers and patients. Early transmission dynamics in Wuhan, China, of novel coronavirusÀinfected pneumonia Efficacy of slit lamp breath shields Respiratory virus shedding in exhaled breath and efficacy of face masks Intra-abdominal pressures during voluntary and reflex cough Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management Coughing and aerosols Barrier enclosure during endotracheal intubation Visualizing speech-generated oral fluid droplets with laser light scattering Footnotes and Disclosure Quality Improvement Grant, Department of Ophthalmology and Vision Sciences keywords: available; borders; breath; cloth; coronavirus; cough; droplets; examination; examiner; face; gloves; inside; lamp; manikin; mask; outer; patients; ppe; respiratory; shields; simulation; slit; slit lamp; spread; surgical; use cache: cord-318835-sd9hbocg.txt plain text: cord-318835-sd9hbocg.txt item: #35 of 41 id: cord-319822-h1zm94p4 author: Carelli, Pasquale title: A physicist's approach to COVID-19 transmission via expiratory droplets date: 2020-06-17 words: 1414 flesch: 54 summary: Droplets and Droplet nuclei How far droplets can move in indoor environments--revisiting the Wells evaporation-falling curve Zdenek Jezek, and others, Smallpox and its eradication A cough aerosol simulator for the study of disease transmission by human cough-generated aerosols Violent expiratory events: on coughing and sneezing Kin-Hang Kokn and others, A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster Xingwang Li and others, A novel coronavirus from patients with pneumonia in China Guangfu Jin, and others, Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China Gisela Bretzel and others, Transmission of 2019-nCoV infection from an asymptomatic contact in Germany The size and the duration of air-carriage of respiratory droplets and droplets-nuclei The size distribution of droplets in the exhaled breath of healthy human subjects Holbrook and others, Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1 On air-borne infection: Study II. keywords: aerosol; air; countries; covid-19; date; droplets; expiratory; ffp3; infected; initial; large; load; masks; particles; people; physicist; radius; smaller; surgical; transmission; viral; virus cache: cord-319822-h1zm94p4.txt plain text: cord-319822-h1zm94p4.txt item: #36 of 41 id: cord-324444-t697xw4y author: Rodriguez-Palacios, Alexander title: Textile Masks and Surface Covers - A 'Universal Droplet Reduction Model' Against Respiratory Pandemics date: 2020-04-10 words: 2465 flesch: 33 summary: As a result, the availability/use of medical masks is discouraged for the public. Together, experiments indicate that two-152 layers of household textiles are as effective as medical masks preventing EnDC, and that more 153 breathable materials in ≥2-layers could be effectively used if individuals deem two-layer, 'denser' 154 textiles too air-restrictive. keywords: author; available; community; contamination; copyright; covid-19; droplets; edb; edbs; effective; endc; environmental; figure; funder; health; individuals; infection; international; layers; license; masks; medical; medrxiv; micro; model; peer; perpetuity; preprint; prevention; reduction; respiratory; spray; surface; textiles; transmission; workers cache: cord-324444-t697xw4y.txt plain text: cord-324444-t697xw4y.txt item: #37 of 41 id: cord-325205-8yug5jjx author: Dbouk, Talib title: On coughing and airborne droplet transmission to humans date: 2020-05-01 words: 5489 flesch: 54 summary: Figure 7 shows the evolution of human saliva droplets, taking into account the dispersion, evaporation, breakup, and droplet settling. An ejection process of saliva droplets in air was applied to mimic the real event of a human cough. keywords: air; airborne; ambient; applied; breakup; carrier; cloud; computational; conditions; cough; coughing; diameter; different; direction; dispersion; distance; distribution; domain; droplet; droplet cloud; environment; equation; evaporation; evolution; fig; flow; fluid; forces; function; ground; heat; human; human cough; humidity; initial; kinematics; larger; liquid; mass; maximum; mouth; number; particle; phase; print; relative; respiratory; saliva; saliva droplet; size; smaller; social; speed; study; temperature; time; total; transfer; transmission; transport; travel; turbulent; velocity; water; wind; wind speed cache: cord-325205-8yug5jjx.txt plain text: cord-325205-8yug5jjx.txt item: #38 of 41 id: cord-334166-vll4s0xq author: Jones, Huw AS title: Reducing Aerosolised Particles and Droplet Spread in Endoscopic Sinus Surgery during COVID‐19 date: 2020-08-15 words: 2615 flesch: 46 summary: A total of three scenarios were tested; 1) Endoscopic Sinus Surgery (ESS) (uncinectomy, middle meatal antrostomy, anterior & posterior ethmoidectomy, sphenoidotomy) using powered suction 4mm microdebrider (4 minute duration) with suction mask and repeated without, 2) Powered drilling of the frontal recess and beak using a 12000 rpm 55 degree integrated suction cutting burr with suction mask and repeated without, 3) Drill activation outside cadaver, within the mask aperture for 20 seconds with and without suction applied. Two models were utilised: smoke to simulate fine particle aerosolization, and fluorescein staining to simulate respiratory droplet spread. keywords: activation; aerosol; aerosolised; aperture; cadaver; cadaveric; care; copyright; covid-19; drill; droplet; endoscopic; external; fine; fluorescein; image; instrument; mask; microdebrider; negative; nuclei; pandemic; particles; powered; pressure; procedures; respiratory; rights; sars; scenario; simulation; sinus; smoke; spread; staff; study; suction; surgery; theatre; transmission; use; valve; viral; white; wood cache: cord-334166-vll4s0xq.txt plain text: cord-334166-vll4s0xq.txt item: #39 of 41 id: cord-335874-mtfe9uq1 author: Chao, C.Y.H. title: Characterization of expiration air jets and droplet size distributions immediately at the mouth opening date: 2008-11-07 words: 6523 flesch: 57 summary: Droplet size was measured using the interferometric Mie imaging (IMI) technique while the particle image velocimetry (PIV) technique was used for measuring air velocity. Droplet size also affects the infectivity of pathogen-laden droplets. keywords: air; air jet; air velocity; angle; average; camera; close; condensation; coughing; current; diameter; different; distance; distribution; droplet size; droplets; duguid; estimated; estimation; evaporation; expiration; expiration air; expiratory; expiratory droplets; fig; high; imi; jet; larger; laser; light; loudon; lower; measured; measurement; method; mm distance; mouth; number; observation; opening; piv; range; reported; results; roberts; safety; sampling; setup; sheet; shield; size; size distribution; smaller; speaking; studies; study; system; technique; temperature; time; total; tube; velocity; volume; volunteers; water cache: cord-335874-mtfe9uq1.txt plain text: cord-335874-mtfe9uq1.txt item: #40 of 41 id: cord-353170-fiadxpar author: George, Ajith title: Correspondence‐Technical Note: Safe Nasoendoscopy Assisted Procedure in the Post COVID‐19 Pandemic Era date: 2020-05-31 words: 815 flesch: 54 summary: On impact with smooth surfaces droplets disperse to smaller sizes and can aerosolise. This is due to the relatively high viral load in a droplet, purely due to its large size, and also the fact that large droplets have weight, and so gravity pulls them down onto surfaces that others can touch -so passing it on. keywords: aerosol; article; dispersion; droplets; infections; mask; microns; mouth; note; risk; size; snap; spread; surgical; transmission; valve cache: cord-353170-fiadxpar.txt plain text: cord-353170-fiadxpar.txt item: #41 of 41 id: cord-356118-7yuzl5he author: Woo, Myung-Heui title: Method for contamination of filtering facepiece respirators by deposition of MS2 viral aerosols date: 2010-10-31 words: 4343 flesch: 48 summary: The number-and mass-based particle size distribution of generated droplets and loaded droplets at 2 Lpm through the aerosol generator plus 3 Lpm dry air and 2-rpm turntable speed. The Q-T-Q and S-T-S CVs of loading density were obtained to evaluate the uniformity. keywords: aerosol; air; artificial; bioaerosols; chamber; concentration; conditions; cvs; decontamination; density; deposition; diameter; different; distribution; droplets; ffrs; fig; filter; flow; frequency; generator; human; influenza; loaded; loading; loading density; lpm; medium; method; min; ms2; mucin; nebulizer; operating; particles; pfu; rate; saliva; sample; shape; size; speed; study; surface; system; temperature; time; titer; transmission; turntable; ultrasonic; uniformity; viability; virus; viruses cache: cord-356118-7yuzl5he.txt plain text: cord-356118-7yuzl5he.txt