Report containing articles, manuscripts, and tabulations of recorded spectra created by the Spectroscopic Laboratory of the University of Chicago.

Report containing articles, manuscripts, and tabulations of recorded spectra created by the Spectroscopic Laboratory of the University of Chicago.

This report analyzes Parian and Teflon that were exposed to solutions of 1AX, 1AS, and 1AF, ANL June 1, 1948 Flowsheet, under conditions described in the following report.

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This document details activities at the Hanford Works during the month of April 1949.

The following is a report of a trip to the Simonds Saw & Steel Company, Lockport, New York, on May 3, 1949. The purpose of the visit was to observe the various operations involved in the rolling of uranium rods at this plant and health problems associated with the rolling operations.

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The quartz-fiber microbalances used in the Mound Laboratory operations are of the conventional Kirk-Craig type, but are housed in vacuum-tight cases which permit foil weighing by remote control.

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Physical and inorganic Chemistry. Studies are reported on: volatile complexes of ZrCl/sub 4/ and HfCl/sub 4/ with POCl/sub 3/; reaction of UCl/sub 4/ with LiAlH/sub 4/; preparation and properties of metal uranates and polyuranates; heats of solution of UO/sub 2/(NO/sub 3/)/sub 2/ hydrates; absorption spectra of Np in HClO/sub 4/, and separation of Np and Pu chlorides by a flow method. Process Chemistry. Extraction of Th from Mailiackrodt U raffinate was studied. Nuclear Chemistry aad Radiochemistry. Invesigations were carried out on: organic tritium; exchange reactions of U ions in solution; exchange reactions of Fe in aqueous solutions: Tc recovery from old Hanford slugs; (a,2n) cross section of Pa/sup 231/; and spontaneous fission counting U/sup 236/ and Pu/sup 238. (T.R.H) l822 Nuclear Chemistry and Radiochemistry. Measurements of the half- lives of Ac/sup 227/ and RaD(Pb/sup 210/) were continued. The effective pile neutron capture cross sections for U/sup 236/ were determined by measuring the activity of the resultant U/sup 237/ with an end window geiger counter. A study of ion chambers for tritium analysis is presented. Procedures were developed for the determination of tritium and C/sup 14/ in onganic compounds. Physical and Inorganic Chemistry. An investigation of the electrochemistry of Np in …

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Note presenting an investigation to determine the fatigue-strength values for 24S-T aluminum alloy when subjected to various ratios of biaxial stresses. The stresses considered were both tensile. The results indicated that uniaxial fatigue-strength values in the longitudinal direction cannot be used to predict the fatigue strength, and that biaxial fatigue strength may be as low as 50 percent of the uniaxial fatigue strength.

"A theoretical solution is presented for the critical axial-compressive stress of a simply supported curved rectangular panel having a central longitudinal stiffener offering no torsional restraint. The results are presented in the form of computed curves and tables. Because a panel of moderate or large curvature buckles in compression at a stress lower than the theoretical value, a method is suggested to aid in determining the critical stress for use in design" (p. 1).

Report presenting an investigation of pitching moments and center-of-pressure locations obtained from a landing investigation in smooth water of a conventional flying boat as compared to values predicted by general hydrodynamic impact theory. Landings were generally moderate and covered as wide a range of trim and velocities as practical. Results regarding the center of pressure and pitching moments are provided.

Note presenting an investigation conducted to determine the oxidation characteristics of molybdenum disulfide and to determine the effect of such oxidation on its role as a solid-film lubricant. A coating of molybdenum disulfide serving as a high-temperature solid-film lubricant maintained low coefficient-of-friction values during its oxidation as long as an effective subfilm of the molybdenum disulfide remained.

Note presenting a theoretical solution for the problem of the compressive buckling of flat rectangular Metalite type sandwich plates with simply supported loaded edges and clamped unloaded edges. The solution is based on the general small-deflection theory for flat sandwich plates developed in a previous report. Results regarding stability orientation and buckling curves, comparison with approximate solution, correction for plasticity, and comparison of theory and experiment are provided.

A lightweight instrument that utilizes resistance-wire electric strain gases to measure propeller-shaft thrust has been developed. A wind-tunnel investigation on a propeller installed, on a single-engine pursuit airplane showed that the instrument gave a reliable indication of propeller-shaft thrust to an accuracy of +/-2 percent within its calibrated range. No attempt was made to determine the relation of indicated shaft thrust to net propeller thrust.

Memorandum presenting an approximate method for the estimation of the properties of the incompressible laminar boundary layer on a flat plate in the slip-flow region using Karman's momentum method. At equivalent stations, the total thickness and the skin friction of a slipping boundary layer are less than that of the normal boundary layer at the same Reynolds number.

An altitude-wind-tunnel investigation of the performance of AN-F-58 and AN-F-32 fuels in an experimental turbojet engine was conducted over a range of simulated altitudes and flight Mach numbers. Combustion efficiencies obtained with AN-F-58 and AN-F-32 fuels were approximately equal. The minimum-speed altitude operational limit was essentially the same with either AN-F-58 or AN-F-32 fuel. Starting characteristics of the two fuels were approximately the same at low wind milling speeds. Visual observation showed no apparent differences in the carbon-deposition rates of AN-F-58 and AN-F-32 fuels.

Report presenting aerodynamic and icing investigations conducted in the icing research tunnel on a model of a turbojet-engine nacelle with a long straight air inlet in order to provide basic design criteria for hot-gas blowback systems. The most uniform temperature distribution was obtained with a bleedback of 4.4 percent at a gas temperature of 1000 degrees Fahrenheit and resulted in an average dry-air-temperature rise of 46 degrees Fahrenheit.

"Pressure-distribution data of the NACA 64(sub 1)-012 and 64(sub 1)A012 airfoils have been analyzed to determine the effects of increasing the trailing-edge angle from 9 to 14 degrees. The primary effect of increasing the trailing-edge angle was to decrease the loading over the rear portion of the airfoil under lifting conditions. The differences in trailing-edge load increased with Mach number and lift coefficient" (p. 1).

Report presenting an investigation to evaluate the effects of split flaps, elevons, sharp leading edges, drooped-nose flaps, and extended-nose flaps on the lift, drag, and pitching-moment characteristics at low speed of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and an aspect ratio of 3.5. Results regarding the plain wing and wing-fuselage combinations, Reynolds number, split flaps, elevons, leading-edge devices, and highest lift coefficient attained before longitudinal instability are provided.

Report presenting an investigation of the damping-in-roll characteristics of a 35 degree sweptback wing, with and without vertical fins, through a range of Mach numbers in the high speed 7- by 10-foot tunnel utilizing a free-to-roll technique. The damping-in-roll coefficient increased in magnitude with Mach number in the manner indicated by theory and generally was found to increase in magnitude with angle of attack over the range tested.

Report presenting an investigation to determine the longitudinal stability characteristics of a complete model equipped with a variable-sweep wing at four different angles of sweepback. The primary objective was to study various wing modifications and an external-flap arrangement designed to minimize the shift in neutral point accompanying the change in sweep angle.