R. D. Trengove

Diffusion coefficients and thermal diffusion factors for five binary systems of nitrogen and a noble gas

Diffusion coefficients, D12, and thermal diffusion factors, αT, are reported for the systems He-N2, Ne-N2, Ar-N2, Kr-N2 and Xe-N2; the D12 values were measured over the temperature range 275–323 K and the αT values at 300 K. The diffusion coefficients were combined with accurate second virial coefficient data to obtain (m, 6, 8) potential parameters and these values, together with existing potential parameters, were used to calculate αT values for comparison with experiment.

Thermal diffusion factors at 300 K for seven binary noble gas systems containing helium or neon

Thermal diffusion factors, αT, have been measured as a function of concentration at 300 K for seven binary noble gas systems containing helium or neon. The results, obtained with a two-bulb cell, are in agreement with those of Saviron et al. who used a thermal diffusion column, and in general greater than those of Taylor et al. who used a 20-tube trennschaukel. The experimental results agree well with values predicted by the Chapmen-Cowling theory and the recent potential functions reported in the literature.

Diffusion and thermal diffusion in some dilute binary gaseous systems between 195 and 400 K: Tests of several asymmetric potentials using the infinite order sudden approximation

Limiting binary diffusion coefficients, D012, for mixtures of He with Ar, O2, N2, CO2 and SF6 and of Ar with N2 and O2, determined by the two-bulb method, are reported for the temperature range 195–400 K. The apparatus, calibrated with absolute data obtained at 300 K with a Loschmidt cell, greatly extends the temperature range covered in this Laboratory, previously limited to 275–325 K. Thermal diffusion factors, αT, have been measured for the systems He-Ar at 350 K with He-O2, He-CO2 and Ar-O2 at 255.3 K. These results together with others previously reported have been used to test several asymmetric potential functions recently published in the literature.

The pressure dependences of the thermal diffusion factors of the systems He-Ar, He-CO6 at 300 K

Thermal diffusion factors, αT, are reported for systems He-Ar, He-CO2 and He-SF6 at 300 K as functions of concentration and pressure. The measured values at finite pressures are compared with those predicted by the theory of Oost et al., and extrapolated zero pressure values with those calculated by the Chapman-Enskog theory to the third Chapman-Cowling approximation.

Diffusion and thermal diffusion in binary mixtures of sulphur hexafluoride with noble gases

Diffusion coefficients and thermal diffusion factors are reported for binary mixtures of sulphur hexafluoride with noble gases. The results are compared with theoretical values calculated by means of the Chapman-Enskog theory, spherical potentials for the like interactions and multi-parameter anisotropic potentials for the unlike interactions.

A study of the concentration and temperature dependence of the thermal diffusion factor of the system Ne + CO2

Abstract Precise thermal diffusion factor, α T , have been measured for the system Ne + CO 2 as a function of concentration and temperature. The results indicate that, as predicted by the Chapman-Enskog theory, α T for this system decreases with decreasing temperature in contrast to results of Weissman, Saxena and Mason.