A flight investigation in natural icing conditions was conducted to determine the effect of inlet ice formations on the performance of axial-flow turbojet engines. The results are presented for icing conditions ranging from a liquid-water content of 0.1 to 0.9 gram per cubic meter and water-droplet size from 10 to 27 microns at ambient-air temperature from 13 to 26 degrees F. The data show time histories of jet thrust, air flow, tail-pipe temperature, compressor efficiency, and icing parameters for each icing encounter. The effect of inlet-guide-vane icing was isolated and shown to account for approximately one-half the total reduction in performance caused by inlet icing.

Two new positron active isotopes, B{sup 8} and Na{sup 20}, have been found to decay to excited states of Be{sup 8} and Ne{sup 20}, which in turn decay 'instantaneously' by alpha emission. Their half-lives are 0.65 {+-} 0.1 sec. and 1/4 sec. respectively. N{sup 12} is also found to have a low energy positron group which leads to an {alpha}-unstable excited state in C{sup 12}. The masses of B{sup 8} and Na{sup 20} are 8.027 and 20.015 respectively. B{sup 8} decays by a 13.7 {+-} 0.3 Mev positron, through the same excited state of Be{sup 8} as does Li{sup 8}. Estimates of the energies of the excited state in C{sup 12} and Ne{sup 20} are made.

The following report contains two parts on the analysis of astatine, neptunium and plutonium. Part A discusses a bent crystal focusing X-ray spectrometer that has been designed and built for the observation of the X-and gamma-rays emitted in association with radioactive decay. The instrument uses proportional counter detection and is described, as well as associated electronic circuits. The plutonium L X-rays from Cm-242 and the neptunium L X-rays from Am-241 have been measures. Values of the energies and abundances are reported. Then in Part B, it discusses some isotopes of astatine hitherto unreported that have been observed in bombardments of bismuth on the University of California 184" cyclotron.

The fission reaction has been observed with high energy accelerator projectiles for elements as light as tantalum but has not been reported for medium weight elements. The present note presents evidence for the occurrence of reactions which are probably most properly described by the term 'fission' and which seem to occur with very small yield throughout the region where this type of reaction is only slightly exoergic or even endoergic with respect to mass balance. In the course of detailed investigation of the spallation of copper and the variation of the product yields with energy of the bombarding particle the threshold for formation of radioactive Cl{sup 38} (38-minute half-life) from elemental studied. The energetically most economical way in which Cl{sup 38} might be spallation reactions is by emission from the bombarded copper nucleus of nucleons in groups such as alpha-particles instead of single nucleons 0 The energetic requirements for the reaction Cu{sup 63}(p,pn6a)Cl{sup 38}, in which the maximum number of alpha-particles are emitted, include (1) the mass difference between the reactants and the products and (2) the excitation energy which the alpha-particles must have in order to pass over the coulombic barrier, Since the reaction is endoergic with respect to …

This note is part of a program with the objective of finding practical ways of reducing the external noise level of light airplanes in order to make them less objectionable to people on the ground. The current report covers noise measurements on standard light airplanes and on similar airplanes equipped with engine mufflers, propeller reduction gears, and propellers with various numbers of blades and blade shapes. The results indicate that reductions in noise level were found to result from muffling the engine and from reducing propeller tip speed and blade loading.

"An investigation has been conducted in the Langley 20-foot free-spinning tunnel to determine the spin and recovery characteristics of a 0.057-scale model of the modified Chance Vought XF7U-1 airplane. The primary change in the design from that previously tested was a revision of the twin vertical tails. Tests were also made to determine the effect of installation of external wing tanks" (p. 1).

Report presenting the available sources of data on the mechanical properties of aluminum alloys at low temperatures and a summary of the material to be found in each source. General conclusions regarding commercially available aluminum alloys are also provided.

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Note presenting a low-turbulence wind-tunnel investigation of an NACA 64A010 airfoil with a porous surface to determine the reduction in section total-drag coefficient that might be obtained at large Reynolds numbers by the use of area suction. This report primarily deals with additional tests of the same airfoil model equipped with a porous skin of lower porosity.

Report presenting a low-turbulence wind-tunnel investigation of an NACA 64A010 airfoil with a porous surface to determine the reduction in section total-drag coefficient that can be obtained at large Reynolds numbers by using area suction. While previous testing has been reported on, the focus of this paper is primarily the results of additional tests of the same airfoil model equipped with a porous skin of lower porosity.

Report summarizing physical studies on Redox solutions and metal waste solutions, including refractometric investigations.

Report presenting an investigation to obtain basic performance and control characteristics of an aerodynamic-servocontrolled rotor system. Results regarding the hovering performance, low-speed flight performance, control effectiveness, transient response to collective pitch, and transient response to cyclic pitch are provided.

The lifetime for the decay of a {pi} meson into {mu} meson and neutral particle was first measured by Richardson and later by Martinelli and Panofsky. The method was the same in both cases: The fraction of {pi} mesons surviving various times of flight is measured by placing photographic detectors at various path lengths from the target. In the experiment reported here we observe the time lag between the two bursts of fluorescence due to mesons decaying in a scintillation crystal. The first burst is due to the stopping of the entering {pi} meson, the second to the {mu}-meson. As is shown in Fig. 1, a particle penetrating the first and into the second crystal starts the sweep (10{sup -8} sec/mm) of an oscilloscope. The pulses in the second crystal are delayed 0.5 x 10{sup -6} sec to allow the sweep to start and brighten and are then photographed. If the responsible particle is a {pi}{sup +} meson which stops in the crystal, it undergoes {pi}-{mu} decay and two pulses appear on the trace. The {mu}{sup +} meson has a range of only 2 mm in the crystal. If its decay electron is detected some time (.5-2.5 x 10{sup -6} …

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Objective: "The laboratory equilibrium study RC-E-1 described in this report was carried out to obtain uranium equilibrium curves at various concentrations of nitric acid and of TBP."

Tests of a 1/5 scale model of a proposed 153-foot high-speed submarine have been conducted in the Langley full-scale tunnel at the request of the Bureau of Ships, Department of the Navy. The test program included: (1) force tests to determine the drag, control effectiveness, and static stability characteristics for a number of model configurations, both in pitch and in yaw, (2) pressure measurements to determine the boundary-layer conditions and flow characteristics in the region of the propeller, and (3) an investigation of the effects of propeller operation on the model aerodynamic characteristics. In response to oral requests from the Bureau of Ships representatives t hat the basic data obtained in these tests be made available to them as rapidly as possible, this data report has been prepared to present some of the more pertinent results. All test results given in the present paper are for the propeller-removed condition and were obtained at a Reynolds number of approximately 22,300,000 based on model length.

Report discussing a performance evaluation of the Thermal Test Unit, a piece of test equipment fabricated to "aid the Hanford Works in experimentally determining heat transfer characteristics for a particular application."

Note presenting formulas and design charts for the lift in cases for wings with rectilinear plan forms swept so that both leading and trailing edges lie within their respective Mach cones. The charts cover a practical range of aspect ratios and plan forms of moderate taper, with tips parallel to the stream. Numerical results and an application of the charts are included.

"An investigation has been made of a partial-span model of the tail surface designed for use on the Hughes Falcon (MX-904) missile to determine the aerodynamic characteristics of the tail and elevator including elevator hinge moment. Data obtained at Mach numbers of 1.62 and 1.96 in the Langley 9- by 12-inch supersonic blowdown tunnel are presented for the condition where the tail was attached to a segment of the foreshortened body" (p. 1).

Memorandum presenting a pressure-distribution investigation of a wing of a complete supersonic aircraft configuration as conducted in the 4- by 4-foot supersonic tunnel at Mach number 1.59 based on the mean aerodynamic chord. The experimental life and drag coefficients were less than those predicted by linear theory. Results regarding section pressure characteristics, section characteristics, spanwise characteristics, and overall wing characteristics are provided.

From Summary: "An investigation is being conducted to determine the performance of the 12-stage axial-flow compressor of the XT-46 turbine-propeller engine. This compressor was designed to produce a pressure ratio of 9 at an adiabatic efficiency of 0.86. The design pressure ratios per stage were considerably greater than any employed in current aircraft gas-turbine engines using this type of compressor. The compressor performance was evaluated at two stations."

"An analysis was made at flight Mach number of 0.9 to estimate performance of nuclear-energy-powered turbojet engine and optimum engine operating conditions and to determine gross weight and load-carrying capacity of airplane powered by such an engine. The size of airplane required to carry disposable load of 20,000 pounds was found to vary from approximately 300,000 to 900,000 pounds depending on assumptions. For a reactor tube-wall mean temperature of 2500 degrees R, turbine-inlet temperature of 2000 degrees R, reactor-free-flow-area ratio of 0.33, reactor-shielding-material specific gravity of 6.0, shielding thickness of 3.0 feet, and altitude of 30,000 feet, the airplane gross weight required to carry a 20,000 payload is 545,000 pounds" (p. 1).

Note presenting testing of bonding processes evaluated by tension tests on sandwich specimens of 1-inch aluminum cubes bonded to a resin-impregnated paper honeycomb core. 6 of the 14 processes gave good-quality bonds which had average strengths of more than 350 psi or more than 75-percent failure in the core when tested at two different temperatures.

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