Memorandum presenting pulse techniques applied to strain gages for increasing the output level and extending the usable range. Bonded and unbonded strain gages which normally operate with exciting potentials between 3.5 and 14 volts operated satisfactorily with 200-volt pulses of 1-microsecond duration and a repetition rate of 350 per second. Results regarding maximum allowable voltages, effective pulse duration, sensitivity, minimum readable signal, effects of cable capacitance and inductance, sensitivity to external noise, and linearity are provided.

A survey of experimental data at supersonic speed indicated that shock-induced separation of a turbulent boundary layer will result for Mach numbers of approximately 1.33 or greater when a theoretical stream static-pressure-rise ratio of approximately 1.89 occurs across a shock interacting with the boundary layer. The significance of this tentative criterion for turbulent boundary-layer separation is discussed with respect to the design of supersonic diffusers.

Report presenting the ignition delays of propane-oxygen-nitrogen mixtures as a function of temperature and composition in a flow system. Results regarding the effect of apparatus parameters, effect of propane concentration, effect of oxygen concentration, effect of temperature, and interpretation in terms of slow reaction kinetics are provided.

Memorandum presenting an investigation of the effect of the addition of approximately 6 percent nickel, cobalt, or platinum on some properties of molybdenum disilicide. These additions resulted in appreciably lowering the modulus-of-rupture strength from that of unalloyed molybdenum disilicide. Results regarding density and particle-size analysis, chemical analysis of bars, metallographic and x-ray analysis, density and resistivity, modulus-of-rupture strengths, thermal shock tests, and oxidation resistance are provided.

Report presenting an investigation of a silicone-diester blend (SD-17) in various bench studies and in a turbopropeller engine to determine its suitability as a lubricant for aircraft engines. The performance of the fluid was satisfactory during more than 17 hours of operation in a T-38 engine with power levels from 1745 to 2400 horsepower. Results regarding bench studies and turbopropeller engine study are provided.

Abstract: "A titrimetric method for the determination of fluoride in plutonium is reported. Prior to a steam distillation of the fluoride, the bulk of the plutonium is separated by precipitation of the sulfate. The fluoride in the distillate is titrated at a pH of 3.2 with 0.001 M thorium nitrate, using chrome azurol-S indicator. Applied to samples containing 1 to 15 parts per million fluoride, the recovery is 87% and the precision on the 95% confidence level is +/- 0.65 ppm."