Conductances of filled two-dimensional networks

Numerical calculations of the conductances of specific two-dimensional networks of conductors whose values are described by a variety of distributions have been carried out. The results are found to differ only slightly from a well-known estimate which predicts that the conductance G of such a network to be given by the value gc, such that a fraction pc of the conductors have g<gc, where 1-pc is the fraction that can be removed randomly before the network ceases to conduct. In the event that pc is (1/2), gc is the median conductance of the distribution of conductors. These results imply that electrical transport is dominated by bottlenecks which have conductances the order of gc, a result which is important in the discussion of a number of threshold phenomena.