"For two- and three-dimensional flow in a compressible medium, a simple relation is given by which, to a first approximation, the quantitative influence of compressibility upon the velocities and pressures can be understood in a clear manner. In the application of this relation the distinct behaviors of two-dimensional and axially symmetric three-dimensional flow with increasing Mach number are brought out. For slender elliptic cylinders and ellipsoids of revolution, calculations are made of the critical Mach number; that is, the Mach number at which local sonic velocity is achieved on the body" (p. 1).

"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).

"During the first flight tests of the Republic XP-84 airplane it was discovered that there was a complete lack of stall warning. A short series of development tests of a suitable stall-warning device for the airplane was therefore made on a 1/5-scale model in the Langley 300 MPH 7- by 10-foot tunnel. Two similar stall-warning devices, each designed to produce early root stall which would provide a buffet warning, were tested" (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).

"On the basis of photographic pictures the laminar flow at a pipe inlet was measured and compared with other measurements and computational results. The test setup is described in detail, and a series of the pictures obtained for turbulent flow is given" (p. 1).

"For the investigation of measuring instruments at higher speeds up to a Mach number 0.7 a tunnel with closed test section was built in 1942 which was as simple and cheap as possible. The blower was a radial blower with straight sheet vanes of 800-millimeter diameter the tips of which were bent backward a little. The blower sucks the air through a honeycomb of diameter 1.2 meter with wide meshes" (p. 1).

"With water as driving medium and delivered medium in a device similar to a simple jet apparatus, the pressure and velocity fields of the mixing zone were explored with a pitot bar; the ratio of delivered to driving volume ranged between the values 0, 1, 2, and 4. An attempt was also made to analyze the mixing flow mathematically by integration of the equation of motion, with the aid of conventional formulas for the turbulent shearing stress, but this succeeded only approximately for the very simplified case that a driving jet is introduced in an unlimited parallel flow, while the pressure over the whole mixing field is assumed to be constant. In spite of these dissimilar assumptions for the theory and the experiment, the form of the measured and the computed velocity profiles indicates a very high degree of approximation" (p. 1).

"An investigation was conducted in the Cleveland altitude wind tunnel to determine the aerodynamic characteristics and the oil delivery critical altitude of the oil-cooler installation of an XTB2D-1 airplane. The investigation was made with the propeller removed end with the engine operating at 1800 brake horsepower, an altitude of 15,000 feet (except for tests of oil-delivery critical altitude), oil-cooler flap deflections from -20 degrees to 20 degrees and inclinations of the thrust axis of 0 degrees, 1.5 degrees, and 6 degrees. At an inclination of the thrust axis of 0 degrees and with the propeller operating, the total-pressure recovery coefficient at the face of the oil cooler varied from 0.84 to 1.10 depending on the flap deflection" (p. 1).

"Because the results of preliminary flight tests had indicated the P-63A-1 airplane possessed insufficient directional stability, the NACA and the manufacturer (Bell Aircraft Corporation) suggested three vertical-tail modifications to remedy the deficiencies in the directional characteristics. These modifications included an enlarged vertical tail formed by adding a tip extension to the original vertical tail, a large sharp-edge ventral fin, and a small dorsal fin. The enlarged vertical tail involved only a slight increase in total vertical-tail area from 23.73 to 26.58 square feet but a relatively much larger increase in geometric aspect ratio from 1.24 to 1.73 based on height and area above the horizontal tail" (p. 1).

Abstract. Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C14, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C14. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C14. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C14 atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this …

Abstract: X-ray energy level diagrams as given in the literature are tabulated for radium, thorium and uranium. A level scheme for protoactinium is derived from the published data. After a brief review of the use of X-ray data in studying outer electronic structure, it is pointed out that differences in the X-ray spectra should exist depending on whether the outer electrons are in f or d orbitals. The observed separation of the OI and OII levels in thorium and uranium indicated that the f levels lie lower than the d. This hypothesis also provides a reasonable explanation for the observed differences between the MIV and MV absorption edges and MIV and MV levels calculated from the emission spectra and the LIII edge.

Monthly report documenting orders, opinions, and other legal statements issued by the Office of the Attorney General in Texas.

The Pine unit was down four times during the month. These were all regularly scheduled shutdowns. Times down vary from 16.9 hours to 19.2 hours. A total of 33.4 tons of metal was discharged. The galvano-meter chamber in experimental hole {open_quotes}A{close_quotes} was replaced. One Special Request was discharged and three tubes have been loaded with Special Request samples. A new bismuth column has been established. Some difficulty has been experienced with high temperatures of both tube exit water and graphite following startup. On one occasion the normal operating level was exceeded for a short period of time.