On the Existence of Minima and Maxima in the Composition Dependence of the Thermal Diffusion Factor and Thermal Conductivity

The kinetic theory of nonspherical molecules is shown to be unable to account for sharp dips in the composition dependence of the thermal diffusion factor and thermal conductivity of He-H2 mixtures; at most only shallow minima can be accommodated. No maxima or minima in the thermal diffusion factor of Xe-CO2 can be accounted for. In view of these results and the recent careful measurements on He-H2 by Taylor and Weissman, it is concluded that the anomalies reported previously are probably spurious.