This report gives weekly progress in pile technology. An exposure of over 96 hours was made with the slug radiographing apparatus from May 22 to May 26. The three pieces subjected to the exposure included one of the special pieces designed for installation of a thermocouple. The thermocouple well in the special pieces showed up satisfactorily and for the first time it was possible to detect spots which could be due to small voids. Crushing and breaking strength measurements made on graphite pieces after an exposure of 1,465 MD/AT in a test hole show no significant changes in these properties as compared with pieces having an exposure of 1,215 MD/AT. Thermal and electrical conductivity measurements have been made on unexposed samples of coke base and lampblack base graphite recently supplied by National Carbon Co. A calculation has been made of the contribution of Sm{sup 149} to the graphite temperature coefficient of reactivity. Corrosion tube 2480-P was discharged. The tube contained 2 unblistered, 24 slightly blistered, 9 moderately blistered, and no extensively blistered pieces. The rear Van Stone flanges of twenty-nine tubes distributed in the B Pile were inspected. Qualitative results showed conclusively that the worst attack occurs in the fringe …

Progress is reported in the physics and engineering aspects of pile technology.

Report presenting an investigation involving a prismatic-float forebody of 30 degrees angle of dead rise subjected to impacts in smooth water as part of a series of impact tests to investigate the effects of angle of dead rise on hydrodynamic loads of floats and hulls. Results indicated that the loads encountered during impacts can be predicted within the limits of experimental accuracy by curves and equations.

Report presenting an investigation in the 18- by 18-inch supersonic tunnel to determine design conditions for optimum performance of shock diffusers at Mach number 1.85 with a series of projecting single-shock cones with varying angles. Each cone was tested with a curved and a straight diffuser-inlet section. The effect of angle of attack was investigated for several configurations.

Report presenting an investigation in the 18- by 18-inch supersonic tunnel to determine the total-pressure recovery obtainable at Mach number 1.85 with a shock diffuser with projective cones designed to produce two oblique shocks ahead of the diffuser inlet. The variation of total-pressure recovery with tip projection was investigated for four cones with different included angles. A maximum total-pressure recovery of 94.5 percent was attained with the best configuration at an angle of 0 degrees.

Note presenting tests of three types of boundary-layer-control suction slots in a two-dimensional diffuser to investigate design criterions and to evaluate the practical minimum total-pressure losses. Testing occurred at a velocity of about 100 feet per second with a boundary layer with a displacement thickness of 0.85 inch and a shape parameter of about 1.8.

Report presenting a method of predicting the dynamic response of airplane wings to gusts by considering only the fundamental mode of bending along with the results of model tests to evaluate the method. Results regarding experimental results and associated calculations, limitations of calculations, and results calculated for effect of change of certain parameters are provided.

Report presenting a lateral-control investigation of 3- and 6-percent chord spoilers projecting on the upper surface of a wing of high-aspect ratio. The spoilers were found to give large rolling moments at Mach numbers below the Mach number corresponding to the break in the rolling-moment-coefficient curves. Results regarding section pressure distributions, rolling-moment characteristics, normal-force characteristics, pitching-moment characteristics, wing-torsional considerations, and hinge-moment characteristics are provided.

Report presenting an investigation of two sharp-edge annular inlets with conical central bodies at low airspeeds in the propeller research tunnel to obtain information concerning the surface-pressure, drag, and pressure-recovery characteristics of the inlets at subsonic flight. Results regarding the nose and inner surface of the diffuser, inlet lips, minimum surface pressures and critical Mach numbers, pressure surveys in inlets, and pressure surveys in diffusers are provided.

"An investigation has been made at large scale of the characteristics of highly swept wings. Data were obtained at several angles of sideslip on wings having angles of sweep of plus or minus 45 degrees, plus or minus 30 degrees, and 0 degrees. The airfoil sections of the wings varied from approximately NACA 0015 at the root to NACA 23009 at the tip. Each wing was investigated with flaps under flection, partial-span split flaps deflected 60 degrees, full-span split flaps defected 60 degrees and split-flap-type ailerons deflected plus or minus 15 degrees" (p. 1).

Report issued by the Bureau of Mines over the manganese deposits in Sierra County, New Mexico. Descriptions of the physicality, and characteristics of the manganese ore are presented. This report includes tables, maps, and illustrations.

"The NACA 23012-4 airfoil was investigated for the purpose of increasing lift by means of blowing out air from the wing, in conjunction with the effect of plain flap of variable contour and slotted flap of 25 percent chord length. The wing also was provided with a hinged nose, to be deflected at will. Air was blown out from the wing immediately in front of the flap; also at the opening between wing and hinged nose,tangentially to the surface of the wing" (p. 1).

Report presenting a method for calculating the local buckling strength of lipped Z-columns with a small lip width. Some experimental data are presented to show agreement between theoretical and experimental results.

Report presenting testing conducted on two airfoils from a series of rectangular-plan-form airfoils of aspect ratios 7.6 and 5.1 and with NACA 65-006, 65-009, and 65-012 sections using the free-fall method. Results regarding the time histories, ground-velocity data, airfoil drag measurements, and drag coefficients are provided.

"The results obtained from a series of flight measurements of atmospheric turbulence within convective-type clouds and from meteorological soundings are presented together with descriptions of the flights and concurrent weather conditions. These results are presented to provide a background of experience for the forecaster and pilot by illustrating the turbulence conditions as indicated by effective gust velocities in convective-type clouds under spring and summer weather conditions along the eastern coast of the United States" (p. 1).

"There are investigated the problems of the flow of a supersonic jet out of a vessel with plane side walls and the problem of the supersonic flow about a wedge when there is a zone of local subsonic velocities ahead of the wedge" (p. 1).

"Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables" (p. 1).

Report presenting the results of an investigation conducted in the altitude wind tunnel to determine the performance of a 20-inch ramjet. The investigation was conducted at a range of altitudes and ram-pressure ratios using preheated 62-octane fuel. A net thrust of 8135 pounds educed to standard sea-level conditions, a net-thrust coefficient of 0.74, and an overall efficiency of 12.6 percent were attained at Mach number 1.845 at which the engine with a 5-foot combustion chamber was operated.

Abstract: In order to calculate the difference between the number of neutrons which cross the x = o plane before and after the channel has been introduced we consider the number of neutrons which cross an element of cylinder wall at a height x1 and in a direction between (see Figure 5).

This report contains the calculation of the number and spacing of poison columns required to hold a 105 pile in the following cases: (1) complete failure of horizontal rods, (2) complete failure of all rods. Using 10% Cd 90% Pb poison columns of 1.44 inch diameter, it is found that 17 poison columns are required to hold the pile in case of complete failure of horizontal rods, and 65 poison columns are required to hold the pile in case of complete failure of all rods.

"A preliminary investigation was made to determine the effects of gamma radiation on the age-hardening rate of an aluminum-copper alloy at temperatures of 32 and 70 degrees Fahrenheit. The gamma radiation from a 100-milligram radium source appeared to have no significant effect on the age-hardening rate of the alloy. A metallographic examination of the test specimens showed no microstructural changes that could be attributed to gamma radiation" (p. 1).

Report presenting testing of a full-scale, semispan, horizontal tail surface for a jet-propelled fighter airplane in the 16-foot high-speed tunnel to determine the variation of the chordwise and spanwise pressure distributions with Mach number. Surface irregularities were found to cause appreciable distortion of the pressure distribution. Results regarding chordwise distributions, spanwise distribution, effect of Mach number on root bending moment, and estimated critical Mach numbers are provided.

"The problem of the intake of air is treated for a missile flying at supersonic speeds and of changing the kinetic energy of the air into pressure with the least possible losses. Calculations are carried out concerning the results which can be attained. After a discussion of several preliminary experiments, the practical solution of the problem at hand is indicated by model experiments. The results proved very satisfactory in view of the results which had been attained previously and the values which were anticipated theoretically" (p. 1).

This report for June, 1947 describes progress regarding ore dressing and pyrometallurgical studies, chemical work, analytical work, and beta counting.