  Reaction-diffusion processes in two-dimensional percolating structures are
investigated. Two different problems are addressed: reaction spreading on a
percolating cluster and front propagation through a percolating channel. For
reaction spreading, numerical data and analytical estimates show a power-law
behavior of the reaction product as M(t) \sim t^dl, where dl is the
connectivity dimension. In a percolating channel, a statistically stationary
traveling wave develops. The speed and the width of the traveling wave are
numerically computed. While the front speed is a low-fluctuating quantity and
its behavior can be understood using a simple theoretical argument, the front
width is a high-fluctuating quantity showing a power-law behavior as a function
of the size of the channel
