Face shields and masks with exhalation valves are not effective at preventing COVID-19 transmission, finds a new droplet dispersal study. (Physics of Fluids journal, 1 September 2020)
https://aip.scitation.org/doi/10.1063/5.0022968------------------------------
Brad Conrad
Director of Society of Physics Students and Sigma Pi Sigma
College Park, MD
(301) 209-3111
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