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Displaying 49051 - 49075 of 74096

Nonlinear Ultrasonic Parameter in Precipitate-Hardened Steels

November 1, 1999
Author(s)
Donna C. Hurley, Davor Balzar, P T. Purtscher
We have investigated several specimens of ASTM A710 steel containing copper-rich precipates with variations in the final aging treatment. X-ray diffraction line-broadening and small-angle neutron-scattering experiments revealed the existence of the

Off- Diagonal Elastic Constants in Fiber-Reinforced Composites

November 1, 1999
Author(s)
H M. Ledbetter, C M. Fortunko, Paul R. Heyliger
We present an alternative to the usual rod-resonance and pulse-echo measurement methods for determining off-diagonal C ij. The new approach - acoustic resonance spectroscopy (ARS) - avoids the above problems by treating, for example, C 12 the same as C 11

Photoionization Efficiency Spectrum And Ionization Energy of Obro

November 1, 1999
Author(s)
R P. Thorn, L J. Stief, T J. Buckley, Russell D. Johnson III, P S. Monks, R B. Klemm
The photoionization efficiency (PIE) spectrum of OBrO was measured over the wavelength range [Lambda] = 86 - 126 nm by using a discharge flow-photoionization mass spectrometer (DF-PIMS) apparatus coupled to a VUV synchrotron radiation source. Bromine

Polymer Composites for Repairing of Portland Cement Concrete: Compatibility Project

November 1, 1999
Author(s)
L Czarnecki, A Garbacz, P Lukowski, J R. Clifton
The impetus for this project has been the continuing deterioration of, and the necessity to repair, a large stock of concrete structures. A two-component system, portland cement concrete (substrate) in contact with a polymer composite (repair) is produced

Pressure Effect on CH 3 and C 2 H 3 Cross-Radical Reactions

November 1, 1999
Author(s)
Askar Fahr, Allan H. Laufer, D C. Tardy
The effect of pressure on the cross- radical reactions of vinyl and methyl radicals have been investigated. These radicals were produced by excimer laser photolysis of methyl vinyl ketone (CH 3COC 2H 3) at 193 nm. The reaction products were detected and

Rearrangement of Perfluorocyclobutyne

November 1, 1999
Author(s)
K B. Wiberg, M Marquez, Carlos A. Gonzalez
The energies of cyclobutyne, perfluorocyclobutyne and related compounds have been calculated at levels from MP2/6-31G* through QCISD(T)/6-311+G*, and also at B3LYP and B3PW91/6-311+G*. The relative energies found with the larger basis sets are quite

Reference Verification Fluids for Flash Point Determination

November 1, 1999
Author(s)
R G. Montemayor, J E. Rogerson, Jennifer C. Colbert, Susannah B. Schiller
The flash point of a liquid material is used to classify whether the material is flammable or combustible. 1,4-dimethylbenzene (p-xylene) has been used historically to verify the proper operation of different flash point test equipment. Because of the

Report of the 84th National Conference on Weights and Measures

November 1, 1999
Author(s)
G M. Ugiansky, J L. Land
The 84th Annual Meeting of the National Conference on Weights and Measures (NCWM) was held July 25 through July 28, 1999, at the Sheraton Burlington Hotel, Burlington, VT. The theme of the meeting was Setting Standards of Excellence in Pursuit of Equity

Selecting Cost-Effective Green Building Products: BEES Approach

November 1, 1999
Author(s)
Barbara C. Lippiatt
The BEES (Building for Environmental and Economic Sustainability) software implements a rational, systematic technique for balancing the environmental and economic performance of building products. The technique is based on consensus standards and designed

Small Angle Neutron Scattering of Solutions of Arborescent Graft Polymers

November 1, 1999
Author(s)
S M. Choi, R M. Briber, Barry J. Bauer, A Topp, M Gauthier, L Tichagwa
Small angle neutron scattering was used to measure the size and shape of arborescent graft polymers as a function of generation number in solution. The radius of gyration of arborescent graft polymers was found to be almost independent of temperature in

Software Quality Lessons From Medical Device Failure Data

November 1, 1999
Author(s)
D Wallace, David R. Kuhn
Most complex systems today contain software, and systems failures activated by software faults can provide lessons for software development practices and software quality assurance. This report presents an analysis of 342 software-related failures of

SSCP Analysis of Point Mutations by Multi-Color Capillary Electrophoresis

November 1, 1999
Author(s)
K Hayashi, H M. Wenz, M Inazuka, T Tahira, Donald H. Atha
Virtually all methods for the detection of mutations (polymorphism or variant) rely on polymerase chain reaction (PCR). Direct sequence determination of a PCR product is the gold standard for identifying mutaions. However, the vast majority of the signal
Displaying 49051 - 49075 of 74096