From Summary: "Wind-tunnel tests of a full-scale two-blade NACA 10-(10)(08)-03 (high camber) propeller have been made for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests have been compared with results from previous tests of the NACA 10-(3) (08)-03 (low camber) and NACA 10-(5)(08)-03 (medium camber) propellers to evaluate the effects of blade-section camber on propeller aerodynamic characteristics."

Report presenting an investigation of the two-dimensional aerodynamic characteristics of several NACA airfoil sections at four Reynolds numbers. Results regarding the minimum drag, maximum lift, lift-curve slope, and angle of zero lift and pitching moment are provided.

Report issued by the Bureau of Mines over the progress made in emergency mine communications. The results of testing done on low-frequency radio communication are presented. This report includes tables, graphs, illustrations, and photographs.

Contains derivations, based on a simplified theory, of approximate relations for low-speed stability derivatives of swept wings. Method accounts for the effects and, in most cases, taper ratio. Charts, based on the derived relations, are presented for the stability derivatives of untapered swept wings. Calculated values of the derivatives are compared with experimental results.

Note presenting an investigation to determine the yield strength, ultimate strength, ductility, and plastic stress-stain relations for 24S-T aluminum alloy when subjected to biaxial stresses. The data were interpreted by a generalized St. Venant theory in an attempt to predict the biaxial stress-strain relations in terms of the uniaxial tensile stress-strain relations. Stress-strain data were also obtained from flat control specimens cut from tubular specimens and compared with tension test data obtained from tubular specimens.

"By consideration of antisymmetrical, as well as symmetrical, buckling configurations, the theoretical shear buckling stresses of clamped rectangular flat plates are evaluated more correctly than in previous work. The results given, which represent the average of upper- and lower-limit solutions obtained b the Lagrangian multiplier method, are within 1 1/4 percen of true buckling stresses" (p. 1).

Report presenting calculations to determine the effect of several operating conditions on the performance of condensers for steam-turbine power plants. The analysis covered a range of turbine-inlet pressures and turbine-outlet pressures for various condenser cooling-air pressure drops, flight speeds, and altitudes. Results regarding steam-cycle performance, effect of turbine-outlet pressure on condenser performance, effect of cooling-air pressure drop on condenser performance, effect of turbine-inlet temperature on condenser performance, and power-plant-weight estimates are provided.

Note presenting a theoretical analysis, based on the linearized equation for supersonic flow, of the characteristics of triangular-tip control surfaces on thin triangular wings. The ratio of lift effectiveness to the hinge moment which resulted from control deflection was equal to the corresponding two-dimensional ratio for the same ratio of flap area to wing area.

This brief report provides recommendations on handling of radioactive materials in the laboratory

The drag coefficients of bombs at high velocities velocity of fall was 97 percent of the speed of sound) (the highest are determined by drop tests and compared with measurements taken in the DVL high-speed closed wind tunnel and the open jet at AVA - Gottingen.

The problems of static and dynamic longitudinal stability both at high speeds and at low speeds are discussed and data are presented which indicate recent progress made in the solution of these problems.

Report presenting an investigation of the problems of static and dynamic longitudinal stability both at high speeds and low speeds as well as information about progress that has been made to solve these problems. The incorporation of large amounts of sweepback on both the wing and horizontal tail can improve the rate of trim changes and stability. Longitudinal stability has been attained for configurations with a sweep angle of 45 degrees with stall-control devices, but experimental proof is needed for these devices.

Determinations of the density and coefficient of thermal expansions of postum (Polonium 210) were attempted on 20 curies of polonium as obtained from production foils.

Report presenting a study of a family of diffusing scrolls designed for use with a mixed-flow impeller and a small-diameter vaneless diffuser. Results regarding a comparison of performance of scrolls and comparison of performance of various compressor configurations are provided.

The following report describes procedures taken to utilize the photelometer to procure the most rapid and reliable determinations, but the goal of the tests presented was to create satisfactory dispersions of particles to analyze.

Abstract: "The uranium content of badly contaminated uranium solutions may be determined quickly using visual comparison methods to an accuracy of [...]. This accuracy may be considerably improved by employing the fluorimeter herein described. Interfering ions and their removal using liquid-liquid extractions are considered."

"The ditching characteristics of the Lockheed XR60-1 airplane were determined by tests of a 1/24-scale dynamic model in calm water at the Langley tank no. 2 monorail. Various landing attitudes, flap settings, speeds, and conditions of damager were investigated. The ditching behavior was evaluated from recordings of decelerations, length of runs, and motions of the model" (p. 1).

"An analytical investigation is made of the effect of shear lag on the bending vibration of wings that are designed essentially as shallow box beams, and a procedure is outlined for incorporating this effect in the determination of bending modes and frequencies. Numerical examples show that shear-lag action in a box beam can have a large influence on its vibration characteristics. The calculations indicate that even though only a small shear-lag action may be observed in a simple static deflection test of the beam, reductions in the second and higher-mode frequencies may be relatively large" (p. 1).

"The effects of outdoor weathering for 2 years and of an accelerated weathering test on the weight, dimensional stability, and flexural properties of selected reinforced plastics were investigated. The results of all tests, both in this report and the previous report (NACA TN No. 1240), indicate that none of the laboratory aging tests correlated with outdoor weathering with respect to all properties and all materials" (p. 1).

The operation of the Fast Reactor is considered in terms of normal equilibrium conditions and normal shut-down. The proposed loading, control rod adjustment and subsequent "floating" operation are discussed. Safety devices and interlocks are described. Temperature and reactivity changes are examined with respect to various system failures, phase changes, and "flashing" of the reactor. Slow changes due to faulty slug cooling are also considered. The calculations were initially based upon 10 kw operation. Performance tests of the mercury system now indicate that 20-kw operation may be feasible.

The operation of the Fast Reactor is considered in terms of normal equilibrium conditions and normal shut-down. The proposed loading, control rod adjustment and subsequent "floating" operation are discussed. Safety devices and interlocks are described. Temperature and reactivity changes are examined with respect to various system failures, phase changes, and "flashing" of the reactor. Slow changes due to faulty slug cooling are also considered. The calculations were initially based upon 10 kw operation. Performance tests of the mercury system now indicate that 20-kw operation may be feasible. (D.E.B.)

Note presenting an investigation in the 15-foot free-spinning tunnel on a research model representative of a present-day trainer or a four-place cabin monoplane, with varied moments of inertia. The tests were made for eight different wing arrangements and four different tail arrangements, including a twin tail. The results of variation of moments of inertia indicated that, within the range of the present tests, uniformly decreasing the moments of inertia led to steeper spins, higher angular and vertical velocities, and faster recoveries.

"A flight investigation in natural icing conditions was conducted by the NACA to determine the effect of ice accretion on airplane performance. The maximum loss in propeller efficiency encountered due to ice formation on the propeller blades was 19 percent. During 87 percent of the propeller icing encounters, losses of 10 percent or less were observed" (p. 1).

Report presenting an investigation to obtain some information concerning the nature and magnitude of the errors involved in computing the landing stresses for large and relatively flexible aircraft when several simplifying assumptions are made. Results regarding the exact solution and approximate solutions are provided. The results suggest that a satisfactory treatment of the landing problem may possibly be obtained from an analysis which assumes that, in landing, the aircraft is an elastic structure subject to the forces or accelerations found in a drop test in which a rigid mass is used.