No subject

the permeable membrane, that the pressure difference across a
practical membrane determines not only the rate of flow of the
desired material, but also the leakage of the undesired.

I suspect that this is due to some molecules such as H2O would only
get "stuck" in the membrane if it's able to discriminate between the
"diameter" of O and N in their respective gases. When sufficient
pressure is applied, the weak repulsive forces between molecules of
the gas and membrane can be overcome to some degree and the
effective diameter reduces.

-- 
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ /  ASCII ribbon campaign | "If we let things terrify us,
 X   against HTML mail     |  life will not be worth living."
/ \  and postings          | Lucius Annaeus Seneca, c. 4BC - 65AD.