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

Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.

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

A report which covers progress on the testing of the General Engineering and Consulting Laboratory Turbine Pump No. 1 from June 16, 1948, to July 31, 1948.

This report records two samples of Xe-135 that have been isolated with activities sufficient for the measurement of the cross section of Xe by the velocity spectrometer technique.

This technical report provides supplementary information on the Brookhaven nuclear reactor. It details added safety systems, tests, expounds on information included in the original report, describes liquid wastes system, and describes different procedures for operating the nuclear reactor.

This is a reference made to a memorandum about the cooperation between the Hanford Site and the US Geological Survey. The US Geological Survey was at the site to work with Hanford on geological problems the site was having. They worked together to locate the water supply wells of the site which would be coordinated with the drilling program. They also worked together on the possible contamination to the 300 and 3000 area wells. (MB)

None

None

None

None

None

None

None

From Summary: "Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section dropped sharply as the ration D/W was increased from zero to about 0.25. The plain specimens showed quite a pronounced decrease in fatigue strength with increasing width. The holed specimens showed only slight and rather inconclusive evidence of this size effect. The fatigue stress-concentration factor was higher for 75S-T than for 24S-T alloy. Evidence was found that a very small hole would not cause any reduction in fatigue strength."

Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.

Memorandum presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Tail-pipe temperature increased from 761 to 1065 degrees Fahrenheit and the jet thrust decreased from 1234 to 910 pounds during a period of 45 minutes in icing. No general conclusions can be reached from the data because the icing condition was relatively light.

"An investigation has been made in the NACA Cleveland icing research tunnel to determine the de-icing effectiveness of an experimental configuration of an Internal electric propeller-blade heater. Two atmospheric Icing conditions and two propeller operating conditions were Investigated in experiments with unheated blades and with heat applied to the blades both continuously and cyclically. Data are presented to show the effect of propeller speed, ambient air temperature and liquid-water concentration, and the duration of the heat-on and cycle times on the power requirements and de-icing performance of the blade heaters" (p. 1).

Note presenting results of mechanical tests of several laminated plastics, including canvas laminate molded at low pressure, grade-C canvas laminate, rayon laminate, paper laminate, and glass-fabric laminate. The following tests were performed: static tension, compression, and torsion tests; long-time creep tests at different stresses on specimens loaded in tension; fatigue tests of unnotched specimens in bending; fatigue tests of notched specimens in bending; fatigue tests in bending at temperatures of -75, 77, and 160 degrees Fahrenheit; and fatigue tests in torsion.

Note presenting the development of fundamental equations for the plastic buckling of a rectangular plate under edge thrusts on the basis of a new set of stress-strain relations for the behavior of a metal in the plastic range. The relations are derived for buckling from a state of uniform compression.

"A tabulation is presented of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables include values of Mach number from 0 to 10.0 in increments of 0.01 and the functions are based on the assumption that air is a perfect gas having a specific-heat ratio of 1.400" (p. 1).

From Summary: "Tests were made to determine bearing yield and ultimate strengths of bare and Alclad 15S-W(exp 1) and 14S-T(exp 1) sheet and plate in thicknesses of 0.064 inch, 0.250 inch, and 0.750 inch. From the results of these tests it was concluded that the ratios of bearing to tensile properties from the with-grain direction were essentially the same as proposed in NACA TN Nos. 901, 920, 974, and 981 for other high-strength aluminum-alloy sheet and plate."

Report presenting bearing tests made of aluminum-alloy sand casings of 195-T4, 195-T6, and 356-T6 to evaluate the bearing strength and tensile properties of the alloys. Comparisons with individually cast bars and specimens machined from slabs indicate that size and form of casing may have a significant effect on mechanical properties. Results of the tensile, compressive, and shear tests are provided in charts and include specified minimum and typical properties for comparison.

Note presenting experiments to study the characteristics of low-aspect-ratio wings at supercritical Mach numbers. The experiments consisted of tests of wings of aspect ratios ranging from infinity to 2. The results indicate that the detrimental effects of compressibility in the supercritical speed range on the stability and performance of aircraft are alleviated to a great degree by the use of low-aspect-ratio lifting surfaces.