  A model for the study of the effective quasistatic conductivity and
permittivity of dispersed systems with particle-host interphase, within which
many-particle polarization and correlation contributions are effectively
incorporated, is presented. The structure of the system's components, including
the interphase, is taken into account through modelling their low-frequency
complex permittivity profiles. The model describes, among other things, a
percolation-type behavior of the effective conductivity, accompanied by a
considerable increase in the real part of the effective complex permittivity.
The percolation threshold location is determined mainly by the thickness of the
interphase. The "double" percolation effect is predicted. The results are
contrasted with experiment.
