Characteristic pore sizes and transport in porous media

Analytic calculations of {Λ}, a pore-size parameter which characterizes surface effects on transport in porous media, are carried out using two distinct approximations: (1) effective-medium theory and (2) percolation ideas recently applied by Katz and Thompson to the permeability of sedimentary rocks. Our calculations suggest that {Λ} may be determined by mercury injection experiments. We also study the phenomenon of electrical surface conduction using both approximations.