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ABSOLUTE THERMAL NEUTRON DETERMINATION. PART II. ABSOLUTE BETA COUNTING OF INDIUM FOILS

Description: Correction factors for the effect of thickness on the selfscattering, self-absorption, and backscattering of beta particles from indium foils were determined for irradiated foils of 0.03 to 100 mg/cm/sup 2/. The data were corrected for the activity produced by epithermal neutrons, self-shielding of thermal neutrons by the foil during irradiation, the backscatter from the foil support, and the contributions of gamma and x rays to the counting rate. The multiple beta spectra of indium produced a minimum in the self-absorption and self-scattering correction curve in the GM detector at approximately 1 mg/cm/ sup 2/ and a maximum at approximately 12 mg/cm/sup 2/. The selfabsorption curve for indium in the 2 pi counter has the expected shape for a beta emitter with multiple spectra. The self-scattering and self-absorption correction factors for a 100 mg/cm/sup 2/ indium foil are approximately 1.5 for a GM detector at 7% geometry and approximately 3 for a 2 pi counter. (D.L.C.)
Date: October 1, 1955
Creator: Koontz, R.L.; Greenfield, M.A. & Jarrett, A.A.
Item Type: Report

S-Acyl Thioctic Acid Derivatives in Aerobacter Aerogenes andScenedesmus

Description: 1. Acetyl thioctic acid has been prepared chemically and i t s chromatographic and acetylating behavior i s described. 2. A C{sup 14} -containing substance has been found in Scenedesmus, photosynthesizing in the presence of a-C{sup 14}-pyruvate, which has properties suggesting that it i s acetyl thioctic acid. 3 . A C{sup 14}-containing substance has been found in Aerobacter aerogenes, metabolizing a-C{sup 14}-pyruvate, which shows the properties of a labile conjugate of thioctic acid with some relatively polar groups. 4. Acetyl thioctic acid i s formed in vitro when light acts on a solution of thioctic acid and pyruvate.
Date: March 30, 1955
Creator: Milhaud, Gerard; Benson, Andrew A.; Fuller, R. Clinton; Milhaud,Vera & Calvin, M.
Item Type: Report

Adaptation of Combustion Principles to Aircraft Propulsion, Volume I, Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

Description: The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.
Date: April 1, 1955
Creator: Barnett, Henry C. & Hibbard, Robert R.
Item Type: Report

An advisory committee report on local government

Description: The ACIR Library is composed of publications that study the interactions between different levels of government. This document addresses local government.
Date: June 1955
Creator: United States. Commission on Intergovernmental Relations. Advisory Committee on Local Government.
Item Type: Book

Aerodynamic characteristics of a 0.04956-scale model of the Convair F-102A airplane at Mach numbers of 1.41, 1.61, and 2.01

Description: Tests have been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.41, 1.61, and 2.01 of various arrangements of a 0.04956-scale model of the Convair F-102A airplane with faired inlets. Tests made of the model equipped with a plain wing, a wing with 6.4 percent conical camber, and a wing with 15 percent conical camber. Body modifications including an extended nose, a modified canopy, and extended afterbody fillets were evaluated. In addition, the effects of a revised vertical tail and two different ventral fins were determined. The results indicated that the use of cambered wings resulted in lower drag in the lift-coefficient range above 0.2. This range, however, is above that which would generally be required for level flight; hence, the usefulness of camber might be confined to increased maneuverability at the higher lifts while its use may be detrimental to the high-speed (low-lift) capabilities.
Date: September 30, 1955
Creator: Spearman, M. Leroy & Driver, Cornelius
Item Type: Report

Aerodynamic Characteristics of a 0.04956-Scale Model of the Convair F-102A Airplane at Transonic Speeds

Description: Tests have been conducted in the Langley 8-foot transonic tunnel on a 0.04956-scale model of the Convair F-102A airplane which employed an indented and extended fuselage, cambered wing leading edges, and deflected wing tips. Force and moment characteristics were obtained for Mach numbers from 0.60 to 1.135 at angles of attack up to 20 . In addition, tests were made over a limited angle-of-attack range to determine the effects of the cambered leading edges, deflected tips, and a nose section with a smooth area distribution. Fuselage modifications employed on the F-102A were responsible for a 25.percent reduction in the minimum drag-coefficient rise between the Mach numbers of 0.85 and 1.075 when compared with that for the earlier versions of the F-102. Although the wing modifications increased the F-102A subsonic minimum drag-coefficient level approximately 0.0020, they produced large decreases in drag at lifting conditions over that for the original (plane-wing) F-102. The F-102A had 15 to 25 percent higher maximum lift-drag ratios than did the original F-102. The F-102A had about 15 percent lower maximum lift-drag ratios at Mach numbers below 0.95 and slightly higher maximum lift-drag ratios at supersonic speeds when compared with those ratios for sn earlier modified-wing version of the F-102. Chordwise wing fences which provided suitable longitudinal stability for the original F-102 were not adequate for the cambered-wing F-102A The pitching-moment curves indicated a region of near neutral stability with possible pitch-up tendencies for the F-102A at high subsonic Mach numbers for lift coefficients between about 0.4 and 0.5.
Date: March 28, 1955
Creator: Tempelmeyer, Kenneth E. & Osborne, Robert S.
Item Type: Report