The report discusses progress on work pertaining to non-equilibrium phenomena in flowing plasmas. Measurements of vibration-translation and vibration-vibration relaxation rates in rapid expansions of mixtures of N2 and CO2 in argon have been made. The results generally exceed those measured in shock-heating and laser-fluorescence experiments, and indicate a deficiency in available theory. Experiments have been conducted to investigate the influence of channel size on the ionization instability, in order to provide a means of extending information on small scale devices to predictions for full sized power generators. It was found, for example, that the effective Hall parameter decreased with increasing channel size. A mathematical model has been formulated to predict the effect of N2 addition on the non-equilibrium properties of argon and alkali-metal-seed plasmas. Agreement between calculated and experimental values of electrical conductivity was quite satisfactory. (Author).