Report discussing change in absorptivity of some rare earth elements over time.

This report studies ammonium dichromate and the conditions it needs to be under in order to precipitate and be isolated from an aqueous system.

The report is about the geophysical year oceanographic program of the Argentine Republic.

From Introduction: "The purpose of this paper is to present and discuss skin temperature measurements from two flight tests. Temperature measurements were obtained to a Mach number of 5.4 on the first flight and to a Mach number of 10.4 on the second flight."

Report presenting fluid-dynamics studies of a tank of fineness ratio 7.0 which was pylon mounted on a simplified two-dimensional flutter model in order to determine the effects of the fluid on flutter. The flutter speed was determined for three cases: with various amounts of water in the tank, with weights with the same mass and moment of inertia as the fluid considered to be a frozen solid, and with weights with the same mass and moment of inertia as the actual fluid. Results regarding the flutter speed, effects of inertia on flutter, and amplitude of flutter are provided.

Report presenting a comparison of the buffet loads measured on wind-tunnel models with loads measured in flight, which indicate that a simple strain-gage measurement can be used in wind tunnel testing that can be used to predict the wing buffet loads on the airplane. The technique appears to be usable for both unswept and swept configurations.

Report presents a comparison of turbofan and turbojet engines for Mach numbers of up to 3.0 and conventional hydrocarbon fuels. There are four parts of the report: a cycle analysis of turbofan engines and information about their designs, a comparison of several commercial engines proposed for the Air Force, component performance and development problems for turbofan and turbojet engines, and a summary and conclusions based on mission studies.

Report presenting an investigation at a Reynolds number of 6,800,000 to determine the low-speed lateral control characteristics of a 20-percent-chord half-span outboard aileron on a wing with 42 degrees of sweepback at the leading edge. The lateral control, aileron hinge-moment, aileron load, and balance-chamber-pressure characteristics were determined for the wing with and without high-lift and stall-control devices for an angle-of-attack range from -4 degrees through the stall.

An investigation of several ejector configurations to determine the ability to handle the air required for engine cooling. The results are limited to investigations of conical-type mixing-section ejectors at ratios of mixing-section minimum diameter to primary-jet-nozzle diameter using unheated air. Results regarding experimental data, generalization of experimental data, spacing for maximum weight-flow ratio, ejector thrust, ejector configurations for constant weight-flow ratio, and selection of ejector design are provided.

Memorandum presenting an investigation in the high-speed 7- by 10-foot tunnel using the transonic bump method to determine the longitudinal stability and control characteristics of a semispan airplane model at transonic speeds. The results indicated an increase in the maneuvering stability through the transonic range, but regions of instability were indicated by the slope of the curve stabilizer incidence for trim against Mach number at all positions tested.

Report discussing an investigation of the vertical plane of the elevator hinge line of a powered model of a bomber to determine the values of downwash and the dynamic-pressure ratio. The equations for calculating these values and the testing procedures are described.

Section data obtained from wind-tunnel tests at Mach number 4.04 and Reynolds numbers of about 5.0 times 10 to the 6th power and 8.4 times 10 to the 6th power are presented for 6- and 9-percent-thick symmetrical circular-arc airfoils with 30 percent chord trailing-edge flaps. Pressure distributions, Schlieren photographs, and force and moment coefficients are included.

Report presenting an investigation at subsonic speeds of a scoop-type air-induction system designed for use at subsonic and supersonic speeds. Measurements of the ram-recovery ratio and static pressures in a scoop-type intake on the upper surface of the fuselage were taken for a large range of mass-flow ratios, angles of attack, and angles of sideslip.

Memorandum presenting the compatibility of pentaborane with aluminum foil, 24S-T and 17S-T aluminum, and 50-50 tin-lead solder in the range of -30 to -50 degrees F for 7 hours, at 90 degrees F for 6.5 hours, and at 70 degrees F for 28 days. Results were evaluated by determination of the loss in weight after the test period, metallographic inspection, and comparison with blanks carried through test conditions without exposure to the liquid. The evaluation of results was made by visual inspection and physical tests of dimensional stability, tensile strength, elasticity, and gain or loss of weight.

Memorandum presenting a consideration of the problems, research status, and future possibilities for high-temperature lubricants and bearings for aircraft turbine engines. The greater heat loads imposed by high-performance engines and practical limitation on cooling will result in increased operating temperatures for bearings and lubricants.

Report presenting testing of a 14-inch supersonic mixed-flow rotor with a supersonic leading edge and an inlet radius ratio of 0.52, which was designed for impulse operation and uniform work output and tested in Freon-12. Results regarding overall rotor performance, entrance flow, distribution of static pressure on the casing, and exit flow are provided.

Report discussing several configurations of a swept-wing fighter airplane to determine the effects of modified applications of the transonic and supersonic area rules on the transonic drag-rise characteristics. Information about the lift and pitching-moment characteristics is also provided.

Report discussing an investigation to determine the effects of combining auxiliary bleed with ejector pumping on the power requirements and test-section flow of an 8-inch by 8-inch slotted tunnel. Two ejector configurations were used and tests were performed at Mach number range of 0.9 to 1.3. Information about the region of supersonic-flow deceleration, diffuser-inlet Mach numbers, total-power requirements, and which ejector characteristics were preferred is provided .

This report lists pertinent NACA papers presenting research results which have a direct bearing on control system design and performance for both piloted and automatically controlled aircraft. Limited reference is also made to NACA reports on aircraft engine controls and to research techniques and instrumentation pertinent to the study of control systems and aircraft dynamics in flight. Reports published between January 1949 and April 1954 are listed in chronological order and cross referenced.

Laboratory fabrication and testing of an inline densimeter.

The operation of the propeller is analyzed by the use of the distribution of forces along the radius, combined with theoretical equations. The data were obtained in the NACA 20-foot wind tunnel on a 4-foot-diameter, two-blade propeller, operating in front of four body shapes, ranging from a small shaft to support the propeller to conventional NACA cowling. A method of estimating the axial and the rotational energy in the wake as a fractional part of the propeller power is given. A knowledge of the total thrust and torque is necessary for the estimation.

It is shown that under very simple and general assumptions the existence of an antiunitary reflection transformation and the charge gauge group implies the existence of an antiparticle corresponding to a given charged particle. Similar consequences follow on replacing the charge gauge group by the baryon gauge group. No assumptions as to specific wave equations, or indeed the existence of local fields, are made.

A program of bench scale leaching and ion exchange testing for the recovery of uranium from liquors produced by leaching Utex ore (Monticello Stockpile 28) was conducted at Monticello, Utah from July 1953 to April 1954.