Report discussing the results of fill and drain holes for hydrostatic pressure tests on head knuckle radius of forged-steel gas storage cylinders.

The following document analyzes one hundred and seventy-seven bevatron tau mesons for Q value of the tau decay, tau spin and parity, and possible polarization effects.

Abstract. The separation of uranyl nitrate from aqueous solutions of 0.635 M thorium nitrate, 3 M nitric acid and 3 M calcium nitrate by extraction with organic solvents has been investigated. Solvents which gave good separations were 2-tthyl hexyl acetate, ethyl benzoate, n-butyl either and beta-beta- dichloroethyl ether. In general, higher esters, ethers and alcohols are better for separating uranium from thorium that the lower homologues. Several solvents were tested at lower nitric acid concentrations. Dibutyl cellosolve gave a very good separation when the solution was 0.1 M nitric acid. Of the solvent mixtures studied that of equal parts of n-butyl ether and dibutyl cellosolve gave a good separation.

Compilation of the papers presented at a NACA conference on transonic airplane design, including stability and control and configurations with extreme sweep. From Introduction: "The purpose of this conference was to convey to those involved in the study of the aerodynamic problems of transonic aircraft these recent research results and to provide those attending an opportunity for discussion of the results."

From experience gained by NACA test pilots in flying at high subsonic Mach numbers and from interpretation of the data obtained, some general precautionary rules for test flying near sonic Mach numbers have been formulated. The reasons for these rules are discussed and observations are made with respect to the hazards arising from undesirable stability and control characteristics which have been noted in test flights of various airplanes. This paper, although written primarily for the attention of test pilots, contains general information of interest to those who are concerned with various phases of flight testing near sonic Mach numbers.

Report presenting a comparison of the transonic aerodynamic characteristics of unswept and 45 degree sweptback wings in the high-speed tunnel and slotted tunnel. The purpose of the investigation was to explore the possibilities and limitations associated with transonic testing of relatively large wings in a rectangular slotted tunnel. Results regarding lift, pitching moments, drag, bending moments, and Schileren photographs are provided.

From Summary: "Results of flight-path computations are presented for launchings from a straight deck and the curved ramp under conditions of insufficient lift at the instant of take-off."

Report presenting an investigation of flutter of wings mounted on the after portion of a body free to pitch was made in the flutter research tunnel. Uniform wings of 0 and 45 degrees sweep were tested at various positions rearward of the pitch axis. A low-frequency flutter was observed on the unswept wing, but no flutter was obtained for the swept wings.

From Introduction: "The purpose of the present paper is to investigate the effect of two-speed gearing on the take-off efficiency under certain conditions. The present paper gives charts from which the efficiencies can be readily computed for optimum rotational speeds. Also included is a brief discussion of the static thrust of thin propellers, including the effect of camber on the static thrust."

A spark energy of 2.13 joules per spark at 1 spark per second produced ignition to an altitude of 50,000 feet at a flight Mach number of 0.6. The minimum power requirements for ignition were obtained from a combination of low spark repetition rates and high spark energy. The altitude-ignition limit was also increased by increasing spark-gap immersion, fuel temperature, inlet-air temperature, and fuel volatility, and by decreasing flight Mach number. The maximum altitude at which flame propagation was accomplished from combusters with spark plugs to combusters without spark plugs to combustors without spark plugs was increased about 5000 feet by increasing fuel volatility.

"A multiple-range potentiometer circuit is described that provides automatic measurement of temperatures or temperature differences with any one of several thermocouple-material pairs. Techniques of automatic reference junction compensation, span adjustment, and zero suppression are described that permit rapid selection of range and wire material, without the necessity for restandardization, by setting of two external tap switches" (p. 1).

"An experimental investigation of the aerodynamics of a slender cone-cylinder body of revolution was conducted at a Mach number of 3.85 for angles of attack of 0 degree to 10 degrees and a Reynolds number of 3.85x10(exp 6). Boundary-layer measurements at zero angle of attack are compared with the compressible-flow formulations for predicting laminar boundary-layer characteristics. Comparison of experimental pressure and force values with theoretical values showed relatively good agreement for small angles of attack. The measured mean skin-friction coefficients agreed well with theoretical values obtained for laminar flow over cones" (p. 1).

Report presenting an investigation of a model of the Douglas X-3 to determine some methods to improve the low-speed longitudinal stability and control characteristics. Some of the components tested included plain and slotted leading-edge flaps and plain, split, and slotted trailing-edge flaps. Results regarding the effect of various factors on longitudinal stability and flap characteristics are presented.

The statistical approach to the gust-load problem, which consists in considering flight through turbulent air to be a stationary random process, is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, normal, and lateral gusts on the wind stresses is also considered.

"An analysis is made of the effects of compressibility on the pressure coefficients about several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of the linearized equations of compressible flow. The results show that the theoretical methods predict the subsonic pressure-coefficient changes over the central part of the body but do not predict the pressure-coefficient changes near the nose. Extrapolation of the linearized subsonic theory into the mixed subsonic-supersonic flow region fails to predict a rearward movement of the negative pressure-coefficient peak which occurs after the critical stream Mach number has been attained" (p. 1125).

Abstract: "A uranium-titanium constitution diagram is presented. There is complete solid solubility between titanium and gamma uranium above about 2100 F. Only one compound exists in the system. It has a hexagonal structure based on U2Ti. It has a fairly wide range of stability, particularly on the titanium side. Beta-titanium solid solution decomposes eutectoidally into alpha titanium and compound at 1150 F. Eutectoid composition is about 72 atomic per cent titanium. Gamma-uranium solid solution decomposes eutectoidally at 1325 F into beta uranium and compound. Eutectoid composition is about 6 atomic per cent titanium. Beta uranium and compound react peritectoidally at 1233 F to give alpha uranium. Solubility of titanium in alpha and beta uranium is low as is the solubility or uranium in alpha titanium."

From abstract: "Using the method of induced radioactivity, the capture cross section of Pb[^]208 for C neutrons is found to be .00045 ± .00015 x 10[^]-24 cm[^]2. This is definitely lower than the value of .001 x 10[^]-24 reported by Maurer and Ramm."

Principles of fire-resistance classifications of building types and materials, general methods for controlling the spread of fire, and general fire-prevention measures.

"An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with the geometry of the combination" (p. 689).

The gust and draft velocities evaluated from acceleration and airspeed-altitude records taken by NACA instruments installed in P-61c airplanes participating in thunderstorm flights 9, 10, and 11 of July 12, 1946, July 17, 1946, and July 18, 1946, respectively, are presented in references 1 and 2 for previous flights. In accordance with a recent discussion with a member of the U.S. Weather Bureau staff, motion-picture records of the pilots' instrument panels for the present flights were inspected to note variations in the readings of a milliammeter used in conjunction with other equipment to indicate ambient air temperature. The inspection indicated that the instrument read zero throughout all traverses.

"In order to determine the aerodynamic effects of an auxiliary belly fuel tank on the Grumman F8F-1 airplane, a wind-tunnel investigation was made on a 1/5 - scale model of the Grumman XF8F-1 airplane. Pitch and yaw tests were made with the model in the cruising and landing configurations for windmilling and take-off power conditions. Tuft studies and static-pressure measurements were also made to determine the flow characteristics in the region of the fuel tank" (p. 1).

This report describes tests of 10 full-scale metal propellers of several thickness ratios at various tip speeds up to 1,350 feet per second. The results indicate no loss of efficiency up to tip speeds of approximately 1,000 feet per second. Above this tip speed the loss is at a rate of about 10 per cent per 100 feet per second increase relative to the efficiency at the lower speeds for propellers of pitch diameter ratios 0.3 to 0.4. Propellers having sections of small thickness ratio can be run at slightly higher speeds than thick ones before beginning to lose efficiency.

There is a continuing high interest in the development of organic coolant technology for application to future Hanford reactors. In addition to the HAPO organic program, two other programs are being sponsored by the Atomic Energy Commission. These include the Naval Reactor program, aimed at a reactor for ship propulsion, and the Civilian Power Reactor program. Because of the similarity of the technical efforts in the three programs, an attempt is being made to establish effective liaison among the programs. To this end, a visit was made to several sites actively engaged in organic development work. These sites and their primary functions are detailed in this report.