It is shown that the known Dubinin-Radushkevich (DR) equation, which i
s widely used in engineering calculations of different technological p
rocesses and, in particular, in the field of chemical protection, foll
ows from an earlier equation representing the interphase equilibrium c
ondition for certain model prerequisites. A physical justification of
the DR equation and its refinement is presented. (C) 1998 Academic Pre
ss.