Thermal properties of heterogeneous solids

A summary of research concerning heat transfer in heterogeneous solids is discussed. The macroscopic description of heat transfer in the heterogeneous medium is of classical interest in many engineering applications. The two phases are presented, with their physical properties being constant. Under these conditions, heat transfer is described macroscopically by a single energy equation. Effective properties and these equations, as obtained from scaling up theories, are briefly reviewed. (author)