Dynamics of infectious disease transmission by inhalable respiratory droplets
And the relevant passage: "Evaporation, being a molecular process, is very fast (Nicas et al. 2005; Morawska 2006); for example, a 20 µm droplet evaporates to a 1 µm diameter droplet within 0.24 s−1 (at 50% ambient relative humidity). Henceforth, we neglect droplet evaporation, and we follow Nicas et al. (2005) to take the post-evaporation diameter (approximately) half the pre-evaporation diameter."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894888/
Oh! How easy it is to confuse!
Start with your claim in post 176: "A few days ago, I read a paper that stated that droplets evaporated by 95% in less than a second (I want to say 1/24 of a second) in a room at 50% humidity."
And the relevant passage (in post 178): "Evaporation, being a molecular process, is very fast (Nicas et al. 2005; Morawska 2006); for example, a 20 µm droplet evaporates to a 1 µm diameter droplet within 0.24 s−1 (at 50% ambient relative humidity). Henceforth, we neglect droplet evaporation, and we follow Nicas et al. (2005) to take the post-evaporation diameter (approximately) half the pre-evaporation diameter."
First: This "example evaporation" formula applies to a 20 µm droplet, which by other discussions in this referenced article would fall to the ground in about 8 seconds. and is NOT oconsidered an "airborn" droplet that would be encountered with a mask. (The Covid-19 airborn aerosol droplets discussed in this thread are less than 2.5 µm droplets)
Second: More importantly, you clearly misinterpret the mathematical formula "0.24 s-1". You have no idea what "0.24 s-1" means in this formula. It certainly does NOT mean 0.24 seconds.