The calculation of shielding the thickness for plutonium is complicated by the many different energies represented in the gamma radiation emitted during decay of the plutonium isotopes. Dose rate predictions are also frequently confused by gamma from varying content of fission product impurities in the plutonium, as well as other gamma radiation induced through alpha and neutron particle absorption within the source material or its environment. After assumptions are made for these many factors the radiation data for shielding determination is still frequently inadequate because of wide variations in dose rates resulting from self-absorption. The degree if self-shielding is in turn dependent on nature of the plutonium compound, degree of compactness, weight, and over-all geometrical distribution of the source material. By preparing a variety of plutonium samples representing combinations of these varying factors, actual dose rates and gamma spectra, as obtained from them, can then be extrapolated for application to specific situations.

This report presents a description of the 7 by 10 foot wind tunnel and associated apparatus of the National Advisory Committee for Aeronautics. Included also are calibration test results and characteristic test data of both static force tests and autorotation tests made in the tunnel.

Maintenance of polarization of polarized protons in a linear accelerator is known to be feasible. Circular accelerators present a different problem, and the investigation of the interaction of orbit dynamics and particle polarization in general is undertaken. The equation of motion of the spin vector of a charged particle in a magnetic field as formulated by Bargmann, Michel, and Telegdi is utilized in the study of depolarization for several accelerators. High values of depolarization are obtained, and means for avoiding such depolarization are suggested. (D.C.W.)

From introduction comments: The present analysis is intended to examine the relations for "adiabatic" injection in general from a different point of view.

The effects of fineness ratio (14.2 and 12.2) and boattailing on aerodynamic characteristics of four bodies of revolution at Mach numbers from 1.50 to 1.99 within a range of angles of attack from 0 degrees 10 degrees at an approximate Reynolds number of 35x10(superscript)6 based on body length were investigated. A comparison of experimental data with available theory is included. At zero angle of attack, fineness ratio has no appreciable effect on model characteristics while boattailing and boattail convergence significantly affect fore drag and base drag.

Report presenting the results of an investigation of flap-type controls on a low-aspect-ratio triangular wing using NACA 0005-63 sections for a constant-chord and a constant-percent-chord control surface. Two flap profiles were investigated: one with a true contour and the other with a blunt trailing edge. Results regarding lift, drag, pitching moment, hinge moment, and rolling moments were obtained for several Mach numbers, a constant Reynolds number, and a range of angles of attack.

"During the flight investigation of the X-1 airplane the hinge moments of the elevator and aileron control surfaces have been measured over a Mach number range extending to above 1.0. The results of these measurements are presented in this paper" (p. 2).

Aerial image shows the result of an airborne radioactive survey over an area of 700 square miles in Sweetwater County, Wyoming with the approximate location of three radioactivity anomalies found. Text describes methods used and discusses the anomalies.

This report is a revision of NACA-TR-357. It was prepared by the Committee on Aircraft Accidents. The purpose of this report is to provide a basis for the classification and comparison of aircraft accidents, both civil and military.

From Introduction: "The effects of variations in altitude, flight Mach number, and exhaust-nozzle-outlet area on the compressor performance characteristics are graphically presented. A complete tabulation of the compressor performance data is also presented."

From Summary: "An investigation was conducted in the NACA Cleveland altitude wind tunnel to determine the operational characteristics of the Westinghouse 19B-2, 19B-8, and 19XB-l jet-propulsion engines. The 19B engine is one of the earliest experimental Westinghouse axial flow engines. The 19XB-1 engine is an experimental prototype of the Westinghouse 15 series, having a rated thrust of 1400 pounds. Improvements in performance and operational characteristics have resulted in the 19XB-2B engine with a rated thrust of 1600 pounds. The operational characteristics were determined over a range of simulated altitudes from 5000 to 30,000 feet for the 19B engines and from 5000 to 35000 feet for the 19XB-l engine at airspeed from 20 to 380 miles per hour."

The following report describes an experiment on the aluminum nitrate process for the conversion of tuballoy tetrafluoride to tuballoy peroxide and the solutions resulting.

The following report covers the results of a general program that was conducted at the Oak Ridge National Laboratory to investigate the effects on plastic materials of exposure to radiation in the pile. In the investigation, several plastics were irradiated, and on removal from the pile, their rates of decay were determined by measurement of gamma activity in an ionization chamber.

"Flow-angle and pressure surveys behind five, thin, pointed-tip wings of varying plan form have been made at Mach numbers 1.62 and 2.41. Schlieren studies at a Mach number 1.93 for the same five plan-form wings were made to illustrate the behavior of the vortex sheet. The surveys were conducted at 1.5, 3, and 4 root chords behind three triangular wings of 50 degree, 63 degree, and 72 degree leading-edge sweep angle, and behind the 50 degree triangular wing reversed" (p. 1067).

This is a summarizing and reviewing report in which almost all the experimental data representing Project work done prior to 1949 on the corrosion of pure uranium are brought together and analyzed. New data obtained in this laboratory on corrosion rates in laboratory atmosphere and on the identification of corrosion products by electron diffraction are included. The data for corrosion in each of several different media have been plotted according to logarithm-of-the-rate versus reciprocal-temperature coordinates; and from these plots values for the energies and entropies of activation of the corrosion reactions have been obtained. By theoretical treatment of the role of oxygen as a negative catalyst, it is shown that this element may be expected to "poison" the corrosion rection and then act as a corrosion inhibitor. A practical significance of these data analyses is that they explain why machined uranium parts stored in inert atmospheres (helium or argon) containing only very small amounts of water vapor will corrode relatively rapidly with the formation of loose powdery oxide, whereas similar parts may be kept in dry air almost indefinitely with formation on their surface of only a discoloring, but adhered, oxide coating.

From Introduction: "This report presents the initial study, the tracking performance of typical fighter airplanes with fixed gunsights. The types of airplanes tested afford two comparisons of particular interest: that between typical World War II and currently operational fighters of greatly increased speed and altitude, and that between conventional and irreversabile power-boosted controls with artificial feel, both installed on the same airframe."

From Introduction: "This report investigates some of the problems involved in scheduling the tailpipe temperature to avoid stall during acceleration. The object of this report is to investigate the dynamics of a closed-loop acceleration control that follows a schedule of tailpipe temperature with rotor speed."

Technical paper issued by the Bureau of Standards over studies conducted on the quality of sole leather. As stated in the introduction, "the development of a simple method for quickly determining the durability of sole leather seemed desirable, and this paper discusses a laboratory apparatus designed for this purpose and also presents the results of tests made to date to determine the relative wear of leather from different parts of the hide" (p. 3). This paper includes illustrations, and photographs.

Appendix containing a statistical summary of hyrogeochemical data from ground and surface water samples to accompany a report on U.S. uranium resources in the Ekalaka Quadrangle in Montana, North Dakota, and South Dakota.

From Introduction: "The present paper is restricted to a discussion of wing theory subject to the assumptions of linearized compressible flow. It therefore employs solutions of Laplace's equation and the wave equation for cases where the boundary condition are specified in the plane of the wing."

From Introduction: "Recent developments in the statistical theory of extreme values (references 4 to 10) have indicated a somewhat more rational approach to the problem of predicting the probability of occurrence The present report summarizes some of these findings, indicates the method of application, and evaluates their applicability to certain gust-load problems ."

The method of spherical harmonic tensors developed Mark for solving the Boltzmann transport equation in isotropic media is herein extended to anisotropic media for cylindrical geometry. A formal solution is given for the case of two concentric cylindrical media, A and B, but no numerical work has yet been done. The following treatment differs from a similar one by the H. K. Ferguson Co. in that the external medium B is assumed to be both a neutron absorber and finite in extent rather than a non-absorber and infinite in extent.

Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile nuclear power plant for military field operation.

"The external wave drag of bodies of revolution moving at supersonic speeds can be expressed either in terms of the geometry of the body, or in terms of the body-simulating axial source distribution. For purposes of deriving optimum bodies under various given conditions, it is found that the second of the methods mentioned is the more tractable. By use of a quasi-cylindrical theory, that is, the boundary conditions are applied on the surface of a cylinder rather than on the body itself, the variational problems of the optimum bodies having prescribed volume or caliber are solved" (p. 131).