Talk:Permeability

There are two distinct definitions of permeability relating to gas transport. Permeability through porous solids by fluid flow, as governed by Darcy's law, is measured in m^2. Permeability through diffusion of gas in solids, as governed by Fick's law, is measured in SI units of mol･m/m2･s･Pa or mol･/m･s･Pa (cancelling the meter term). The permeability due to diffusion and ficks law should be included in this page as its absence suggests that permeability due to ficks law and darcys law are the same which is a pretty easy mistake to make. The book Whittington's Dictionary of Plastics, Third Edition By James F. Carley (https://books.google.ie/books?id=791DhiI-D88C&pg=PA353&lpg=PA353&dq=darcy+mol+m+s+pa&source=bl&ots=tybSucKvuF&sig=I_P1p4OT03qtsCXSqbpAMckw7hI&hl=en&sa=X&ved=0ahUKEwizs4TTwrPJAhVDJQ8KHQ7bBLIQ6AEIIDAA#v=onepage&q&f=false) defines the difference between the two. Mike F — Preceding unsigned comment added by 109.76.45.4 (talk) 18:35, 28 November 2015 (UTC)