There were no cases of unusual blistering of slugs being followed under Production Tests. Two normal production tubes were borescoped following trouble with discharge. In Tube 3188-D a distorted slug became stuck in the region of sharp curvature near the inner end of the rear gun barrel; this is the first time this phenomenon has occurred. Examination of irradiated slugs of rolled metal after normal exposure indicates that rolled material has no particular advantages over extruded material from the standpoint of blistering. However, no extensively blistered pieces were found in either the rolled metal are being held for more extended exposure. Inspection of a large number of Van Stone flanges in the D and F Piles has confirmed that the inlet flanges are in generally good condition but that the rear Van Stone flanges of tubes in the 0.140-inch orifice sone of both piles were badly corroded and generally contained deep pits that extended about half-way through the flange. The Van Stone test units are to be installed unshielded in the risor room at the rear of the D Pile, since the shielding required in the X Sample Room exceeded the allowable floor loading. Recent experimental observations indicate that solid …

This monthly report details Engineering Department technical activities for the month of May 1947.

"In the present paper, under the same lineaeizing assumptions as are made in the derivation in reference 1 but with the explicit consideration and simplification of the form of the wake extending from the rear of the airfoil, the methods of Theodorsen (reference 2) have been extended to obtain the forces on the airfoil not only at a fixed angle of attack but also in arbitrary motion" (p. 1).

"The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance" (p. 397).

"Requirements of an automatic engine control, as affected by engine characteristics, have been analyzed for a direct-coupled turbojet engine. Control parameters for various conditions of engine operation are discussed. A hypothetical engine control is presented to illustrate the use of these parameters. An adjustable speed governor was found to offer a desirable method of over-all engine control. The selection of a minimum value of fuel flow was found to offer a means of preventing unstable burner operation during steady-state operation" (p. 1).

Abstract: The erroneously high values for uranium content of salvage solutions as determined by the ether extraction-ascorbic acid procedure have been demonstrated to be due to the presence of colored organic materials in these solutions. Evaporation of such solutions to fumes of HC104 before extraction has been shown to be completely successful in preventing such interference while pretreatment with activated carbon is sufficiently successful for application in Control laboratories. Complete procedures for application of either protreatment and results of such application to composite salvage solutions received over a six-month period are included.

Report issued by the U.S. Bureau of Mines on the sampling of chrome ore deposits in the western United States. Physical properties of the samples collected are presented. This report includes tables.

Abstract: A TEC regulator amplifier driving an Eaterline-Angus recording meter was used to record magnet current variations. Tests were made to determine magnet current variations. Tests were made to determine magnet current stability for currents from 500 amperes to 4000 amperes. Changes were necessary in both the TEC and GE regulators before currents below 2500 amperes could be regulated. Regulation to 0.025 percent for and hour was obtained for currents of 1000 to 4000 amperes with the TEC and GE regulators, and regulation to 0.05 percent for 500 ampere currents.

A major problem encountered in the Manhattan Project was the protection of workers against damage resulting from acute or chronic exposure to external radiation. The problem of how to detect evidence of damage following exposure to total body radiation led to this study. These studies were conducted between January, 1942 and November, 1945. Three groups of persons were employed in this study. The first group of eight individuals harboring incurable neoplasms which was not extensive enough to influence general health, these patients were treated with 400 KV x-radiation while sitting in a wooden chair, doses were 27, 60, and 120r. Three persons having generalized illnesses chronic in nature were given total body radiation using 200 KV X-rays in multiple exposures totaling 100, 300, and 500r. A third group of normal volunteers from personnel of the Metallurgical Laboratory were treated with 200 KV x-rays in three divided doses totaling 21 r. Changes in peripheral blood in the fourteen individuals is reported. In group 1 the most persistent abnormality noted was a diminution in the number of lymphocytes after completion of the treatment. In group 2 a depression in the lymphocytes was also the most marked single change. In group 3 no …

"A simple approximate method is given for the calculation of isentropic irrotational flows past symmetrical airfoils, including mixed subsonic-supersonic flows. The method is based on the choice of suitable values for the streamline curvature in the flow field and the subsequent integration of the equations of motion. The method yields limiting solutions for potential flow. The effect of circulation is considered" (p. 1).

"The problem of turbulence in aerodynamics is at present being attacked both theoretically and experimentally. In view of the fact however that purely theoretical considerations have not thus far led to satisfactory results the experimental treatment of the problem is of great importance. Among the different measuring procedures the hot wire methods are so far recognized as the most suitable for investigating the turbulence structure" (p. 1).

Report presenting a method for the calculation of the buckling stress of a multiweb wing in bending as well as design charts based on this method for the minimum-weight design of 24S-T aluminum alloy sheets, extruded 75S-T aluminum alloy, and extruded 0-1HTA magnesium alloy. An example of the use of the charts is also provided.

The Classified List includes all classes of publications available for distribution to depository libraries. This list includes the selections made by the North Texas State College library beginning in April 1948.

From Summary: "Three methods for calculating span load distribution, those developed by V.M Falkner, Wm. Mutterperl, and J. Weissinger, have been applied to five swept wings. The angles of sweep ranged from -45 degrees to +45 degrees. These methods were examined to establish their relative accuracy and case of application. Experimentally determined loadings were used as a basis for judging accuracy. For the convenience of the readers the computing forms and all information requisite to their application are included in appendixes. From the analysis it was found that the Weissinger method would be best suited to an over-all study of the effects of plan form on the span loading and associated characteristics of wings."

"It is known that compression shocks which lead from supersonic to subsonic velocity cause the flow to separate on impact on a rigid wall. Such shocks appear at bodies with circular symmetry or wing profiles on locally exceeding sonic velocity, and in Laval nozzles with too high a back pressure. The form of the compression shocks observed therein is investigated" (p. 1).

Note presenting a theoretical solution for the buckling stresses of long plates with transverse curvature loaded in shear and longitudinal direct stress. The theoretical critical-stress combinations for plates with either simply supported or clamped edges are given in figures and tables and a comparison is made with previous theoretical solutions. Results regarding the theoretical results, empirical results and design curves, and some interaction formulas are provided.

"A theoretical solution is presented for the determination of the combinations of direct axial stress and torsion which cause thin-walled cylinders with either simply supported or clamped edges to buckle. This theoretical solution is used in conjunction with available test data to develop empirical curves and formulas for use in design. Comparisons are made with theoretical and empirical solutions obtained in other investigations" (p. 1).

"A theoretical solution is presented for the buckling stress of long plates with transverse curvature loaded in shear. The results are given in the form of curves and formulas for plates with simply supported or clamped edges for a wide range of plate dimensions. Comparisons are made with theoretical solutions obtained in previous investigations" (p. 1).

"Empirical design curves are presented for the critical stress of thin-walled cylinders loaded in axial compression. These curves are plotted in terms of nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75" (p. 1).

Note presenting a theoretical solution for the critical stress of thin-walled cylinders loaded in torsion. The results are presented in terms of simple formulas and curves which are applicable to a wide range of cylinder dimensions. The theoretical results are found to be in fairly good agreement with experimental results.

The crystal structures of alloys 61, X-40,X-50, 422-19, 6059, and Vitallium, derived from x-ray diffraction, are discussed. The alloys have been, or are being considered for use in gas turbine applications. The predominant phase was a solid solution of the face centered cubic type of the principal constituent elements.The lattice parameters were found to be between 3.5525 and 3.5662.

Report from the U.S. Bureau of Mines over the studies conducted on the Daisy mine and the Hillside mine in Hardin County, Illinois. Properties of the mines, and the types of mineral deposits found in each are presented. This report includes maps, and illustrations.

The Russian AM 35 and AM 38 aircraft engines have superchargers with a swirl throttle, which appears to be a purely Russian development. This paper gives the results of test runs of the two engines, including the effects of the swirl throttle on engine performance.

Note presenting an investigation to determine the reduction in drag that could be obtained for a conventional-type flying-boat hull by means of aerodynamic refinements. For comparisons, tests were made on a streamline body simulating the fuselage of a modern transport airplane.