On the heat flux derived by the moment method in Lorentzian plasma between hot and cold walls

Reasons for disagreement are considered for two expressions of heat fluxes. One is the expression obtained by taking special limit of a general expression for the heat flux, which holds for arbitrary values of collisionality parameter L/lambda, lambda being the mean free path, derived by the moment method in the Lorentzian plasma between hot and cold walls (heat baths) separated by the distance L. The special limit is the collisional limit L/lambda approaches infinity and I sub c/t sub h approaches the temperatures of cold and hot walls. The other is the one derived by Landshoff, which is exact for the Lorentzian plasma in the linear theory. The differences comes from the nonlocal nature of the former heat flux, while Landshoff's one is based on the local nature.