Work has continued to focus on resistive, viscous, magnetohydrodynamic (MHD) steady states that model tokamak configurations. Recent emphasis has been on the subject of plasma rotation, and the stabilizing effects it has on the kind of MHD activity that results when current thresholds are exceeded in non-rotating configurations. The author believes that relatively superficial consequences of the effects of rotation (e.g., the {open_quotes}velocity shear layer,{close_quotes} which must result when any fluid of whatever nature is rotated in the presence of a material boundary) have been assigned causative effects that do not belong to them, in the presently-dominant perspective on the subject. Output from the author`s three-dimensional spectral-method numerical code has shown how rotation may be made to suppress helical deformations of the current channel and paired helical vortices in a supercritical magnetofluid column. A velocity {open_quotes}shear layer{close_quotes} results if and when there is wall friction. The role of ion parallel viscosity (rather than shear viscosity) in determining stability boundaries in current-carrying magnetofluids is being investigated. A lattice-Boltzmann equation method of computing three-dimensional magnetohydrodynamic toroidal effects is under consideration.

Gas-oil gravity drainage experiments in a layered system which were carried out in 1993 are analyzed. The analysis reveals that the shape of the gas relative permeability governs the arrival of the gas phases at the interface between the layers. Based on the analysis of the experiments, it is concluded that, unlike gravity drainage in homogeneous media, the gravity drainage performance of layered media for the unstable downward gas fingering case, is sensitive to the gas relative permeability curve.

This report summarizes the laboratory studies investigating the electrolytic treatment of alkaline solutions carried out under the direction of the Savannah River Technology Center from 1985-1992. Electrolytic treatment has been demonstrated at the laboratory scale to be feasible for the destruction of nitrate and nitrite and the removal of radioactive species such as {sup 99}Tc and {sup 106}Ru from Savannah River Site (SRS) decontaminated salt solution and other alkaline wastes. The reaction rate and current efficiency for the removal of these species are dependent on cell configuration, electrode material, nature of electrode surface, waste composition, current density, and temperature. Nitrogen, ammonia, and nitrous oxide have been identified as the nitrogen-containing reaction products from the electrochemical reduction of nitrate and nitrite under alkaline conditions. The reaction mechanism for the reduction is very complex. Voltammetric studies indicated that the electrode reactions involve surface phenomena and are not necessarily mass transfer controlled. In an undivided cell, results suggest an electrocatalytic role for oxygen via the generation of the superoxide anion. In general, more efficient reduction of nitrite and nitrate occurs at cathode materials with higher overpotentials for hydrogen evolution. Nitrate and nitrite destruction has also been demonstrated in engineering-scale flow reactors. In flow …