From abstract: "Critical assembly tests have been made on the Pajarito Universal Machine to determine the safety limits of handstacking cubes of 95% U-235 in spherical geometries preparatory to making critical assemblies of U-235 in an "infinite" tuballoy tamper. The U-235 cubes were stacked as pseudospheres in a cavity at the top of a tuballoy block 12" high and 8" on a side, and the assembly tamped by locating it inside a doughnut shaped water tank whose tamping effect is equivalent to the tamping caused by personnel necessary for hand stacking."

Report discussing a plasma containment configuration which appears to have no escape cone. From abstract: "Arguments are given to show how the containment process works, including experimental evidence deduced from published reports on "electromagnetic levitation."

Abstract. Slow neutron transmission measurements as a function of the time of flight of the incident neutron have been made for three different thicknesses of Beryllium. The energy region from 0.004 eV to 50 eV was investigated using the Columbia neutron beam spectrometer system. Particular emphasis was placed on the very low energy region (from 0.004 eV tp 0/2 eV or from 0.6 to 5 [length]) where pronounced crystal interference effects were observed. The effective slow neutron cross section (in the unity of X 10(-24)ce(2)atom) for several different energy values were: 6.1 at 0.2 [length], 3.5 at 1.5 [length], 2.3 at 2.5 [length] and 0.6 at 4.6 [length]. The positions of the discontinuities in the cross section agree fairly well with the values obtained from the X-ray measurements.

Memorandum presenting an investigation of the effect of base bleed on the base force of a supersonic-interceptor model in the 8- by 6-foot supersonic wind tunnel. Two groups of fixed-geometry nozzles and shroud combinations simulating double-iris-type configurations were evaluated over a range of secondary to primary exit-diameter ratios.

Memorandum presenting an investigation of the theoretical performance of a two-stage ballistic rocket missile with a centerbody and two parallel boosters for JP4-oxygen and ammonia-fluorine propellants. The missile using the ammonia-fluorine propellant weighs about one-half as much as a missile using JP4-oxygen. Results regarding the optimum missile and effect of variation of design parameters are provided.

Report presenting an investigation of the low-speed, power-off stability and control characteristics of a model of the McDonnell XF3H-1 airplane. Flight testing occurred in the clean and slat- and flaps-extended conditions over a range of lift coefficients.

Memorandum presenting an investigation of the effect of base bleed on the base force of a supersonic-interceptor model in the 8- by 6-foot supersonic wind tunnel. Generally, base pressures greater than ambient were obtained at the engine operating pressure ratios of the primary nozzle.

Report presenting a wind-tunnel investigation of a semispan model of a wing swept back 63 degrees with an aspect ratio of 3.5 and a taper ratio of 0.25. The tests were conducted to evaluate the effects of Reynolds and Mach number on the aerodynamic characteristics of the wing. Results regarding the characteristics of the wing with the elevon undeflected, effectiveness of the elevon, effects of roughness strips, and effect of model deflection under varying loads are provided.

"At the request of the Bureau of Aeronautics, Navy Department, an investigation of the low-speed, power-off stability and control characteristics of a 1/10-scale model of the McDonnell XF3H-1 airplane has been made in the Langley free-flight tunnel. Flight tests of the model in the clean and in the slats-and-flaps-extended conditions were made over a lift-coefficient range from about 0.5 through the stall. Only low-altitude conditions were simulated and no attempt was made to determine the effect on the stability characteristics of freeing the controls" (p. 1).

It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R. G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of operating conditions is presented. The present analysis shows that the fin analogy may be extended to the form of the side-force expression and that the effective fin area may be taken as the projected side area of the propeller.

"An analytic method for the design of automatic controls is developed that starts from certain arbitrary criterions on the behavior of the controlled system and gives those physically realizable equations that the control system can follow in order to realize this behavior. The criterions used are developed in the form of certain time integrals. General results are shown for systems of second order and of any number of degrees of freedom. Detailed examples for several cases in the control of a turbojet engine are presented" (p. 207).

Memorandum presenting a calculation of theoretical values of rocket performance parameters for JP-4 fuel and various mixtures of liquid fluorine and liquid oxygen, assuming equilibrium and frozen composition during the expansion process. Data were calculated at several equivalence ratios for each assigned fluorine-oxygen mixture. Some of the parameters explored include specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, and ratio of nozzle-exit area to throat area.

Report presenting an experimental investigation of the performance capabilities of an asymmetric swept nose inlet of circular projection in the supersonic wind tunnel at a Mach number of 3.85. The aysmmetric inlet was evaluated in terms of its pressure recovery and mass-flow characteristics for angles of attack up to 9 degrees. Results regarding diffuser performance, supercritical flow patterns, oblique shocks, subcritical stability ranges, and Mach number profiles are provided.

Report presenting a preliminary experimental investigation of the performance capabilities of an asymmetric swept nose inlet of circular projection in the supersonic wind tunnel at a Mach number of 3.85. The performance of the inlet was compared with previously reported performance for more conventional, axially symmetric, annular nose inlets.

"A transonic turbine designed for a maximum blade-surface relative Mach number of 1.57 was investigated experimentally. The performance of the turbine is compared with that of three other transonic turbines that were previously investigated" (p. 1).

Report presenting results of a study regarding the critical masses and nuclear properties of plutonium as well as the use and effects of various tampers.

The purpose of this note is to recalculate the semi-empirical curve of neutron yield vs. deuteron energy originally obtained by H. York in order to predict, using it and the best available data, what yields may be expected for deuterons on uranium in the extrapolated energy region.

From introduction: "The measurement of the thermal conductivity of liquid TF6 presented unusual difficulties because of two of its properties which necessitated working with a closed system. The properties were (1) the liquid can exist as such only above 64.05°C. at which temperature its saturated vapor pressure is 1140 mm. of mercury, and (2) the compound reacts rapidly with moist air. Also because of the liquid's extremely corrosive nature, it was necessary to design a cell of special corrosion resistant materials."

Memorandum presenting a turbojet engine with a centrifugal-flow compressor which permitted overspeed, overtemperature operation and was modified for spray cooling. The effectiveness of spray cooling as a method which permits operation at overspeed, overtemperature conditions with this engine was investigated and the overspeed, overtemperature performance was obtained. Results regarding the cooling system performance, turbine performance, and engine performance are provided.

Report presenting an experimental investigation conducted in the supersonic wind tunnel at three Mach numbers on a translating-spike inlet analytically designed to keep the cone shoulder downstream of the cowl-lip station without a net internal contraction. The inlet in this investigation had an internal cowl-lip angle of 17.5 degrees and was constructed to have the same inlet capture area and maximum cross-sectional area as a previously tested inlet with an internal cowl-lip angle of only 7 degrees. Results regarding the total pressure recovery, effect of spike translation, external drag coefficients, and effective thrust parameter are provided.

Report issued by the Bureau of Standards discussing laboratory testing of hosiery to determine production costs and to make comparisons. Different manufacturing methods and possible defects are presented. This report includes tables, illustrations, and photographs.

"An investigation was made in the Cleveland Altitude wind tunnel to determine the performance of an Aeroproducts H20C-162-X11M2 four-blade propeller on a YP-47M airplane at high blade loadings and high engine powers. The propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements are indicative only of trends in propeller efficiency with changes in power coefficient and advance-diameter ratio because unknown interference effects existed during the investigation" (p. 1).

From Summary: "An investigation was conducted in the Langley impact basin of the water loads on a half scale model of the XJL-1 hull whose forebody has a vee bottom with exaggerated chine flare. The impact loads, moments, and pressures were determined for a range of landing conditions. A normal full-scale landing speed of 86 miles per hour was represented with effective flight paths ranging from 0.6deg to 11.6deg. Landings were made with both fixed trim and free-to-trim mounting of the float over a trim range of -15deg to 12deg into smooth water and into waves having equivalent full-scale length of 120 feet and heights ranging from 1 to 4 feet."

"The results of an investigation of a 1/3-scale model of the Chance Vought XF5U-1 airplane in the Langley full-scale tunnel are presented in this report. The maximum lift and stalling characteristics of several model configurations, the longitudinal stability characteristics of the model, and the effectiveness of the control surfaces were determined with the propellers removed. The propulsive characteristics, the effect of propeller operation on the lift, and the static thrust of the model propellers were determined at several propeller-blade angles" (p. 1).