Partial structure factors and atomic dynamics in conformal solutions

The model of conformal solutions, introduced to study the thermodynamics of liquid mixtures by Longuet-Higgins, is used to calculate the partial structure factors S ij ( q ) of a binary liquid. Explicit expressions are given, in terms of the pair interaction and the radial distribution function for the reference liquid, for the number-concentration structure factors of the mixture. Results are also obtained for transport properties, in particular for interdiffusion and thermal diffusion ratio. Finally some relevant experiments are proposed.

The stability of a layer of binary gas mixture heated below

This paper investigates the Bénard problem in a binary mixture of dilute gases in which an imposed vertical temperature gradient induces a concentration gradient owing to the thermal diffusion effect. The transfer equations are derived by first-order perturbation theory which leads to instability criteria. Numerical results indicate that instability will set in only as stationary convection. This is distinctly different from the cases of liquids and concentrated gases, in which the thermal diffusion (or Soret) effect gives rise to oscillatory instability. It is disclosed in the study that the destabilization of the dilute gas-mixture layer is enhanced by an increase in the thermal diffusion ratio and/or the molecular weight ratio of the species.