A membrane demineralizer has been tested in a pressurized loop. The loop water resistivity was maintained in the 1-2 megohm range by ionized solid transfer in the demineralizer. The size and power requirement of the unit tested per gpm flow through the unit, were 2.3 cu ft and 100 watts. In view of the fact that present designed could reduce the size and required maintenance, further studies may be warranted.

The problem of a blast wave propagating through an inhomogeneous atmosphere is set up for computation by the CRC LORA. Previous treatments of this problem have used various simplifying assumptions such as that of purely radial flow. Since, however, pressure gradients in this situation will not in general be in the direction of rays from the blast center, non-radial flow will exist, and there is reason to believe that for large distances this effect will play a prominent role. Therefore, a program was set up for the numerical calculation (on the CRCLORA) of the propagation of a blast wave from a ground burse with altitude effects and possible tangential flow taken into account. With initial conditions known, the program is designed to give the pressure, density, radial and tangential flow velocities after successive time intervals at 16 equally spaced positions on each of 16 straight rays emanating from the point of burst. These positions are shifted with time to keep up with the shock front. Rehmeyer's and Van Neumann's method is used to handle the discontinuous shock front. In this method an artificial viscosity term is introduced in the the equations of motion in order to smooth out the discontinuity, …