  The relationship between effective conductivity and cell structure of
polyethylene/carbon composites as well as between effective conductivity and
spatial distribution of carbon black are discussed. Following Yoshida's model
both structures can, in a way, be said to be intermediate between the well
known Maxwell-Garnett (MG) and Bruggeman (BR) limiting structures. Using TEM
photographs on composites with various carbon blacks we have observed that the
larger is Garncarek's inhomogeneity measure H of two-dimensional (2D)
representative distribution of the carbon black, the smaller is the effective
conductivity of the composite.
