GREENS-FUNCTIONS FOR A SYSTEM WITH A THIN MEMBRANE

A procedure to determine concentration profiles of solute in a system with a thin membrane is presented. We assume that the permeability of the membrane is described by a set of general coefficients without the need to investigate its internal structure. This procedure is based o n the Smoluchowski equation, but the boundary condition on the membran e is given in a new form. The membrane permeability coefficients are g iven separately with respect to the diffusion, convection, and migrati on phenomena. The procedure, relative to existing procedures, consider ably reduces the calculations necessary to determine concentration pro files.