U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 49076 - 49100 of 74137

High-Temperature Properties of Liquid-Phase-Sintered A-Sic

November 1, 1999
Author(s)
R P. Jensen, William E. Luecke, N P. Padture, Sheldon M. Wiederhorn
We have characterized the high-temperature subcritical crack growth and oxidation resistance of a liquid-phase-sintered (LPS) SiC with 20% volume fraction yttrium aluminum garnet (YAG) second phase. Constant stress rate testing in air in the temperature

IGBT Model Validation for Soft-Switching Applications

November 1, 1999
Author(s)
David W. Berning, Allen R. Hefner Jr.
Techniques are described for validating the performance of Insulated-Gate Bipolar Transistor (IGBT) circuit simulator models for soft-switching circuit conditions. The circuits used for the validation include a soft-switched boost converter similar to that

Ionizing Radiation Induced Degradation of a Tetrachlorobiphenyl in Transformer Oil

November 1, 1999
Author(s)
M Chaychian, Joseph Silverman, M I. Al-Sheikhly, Dianne L. Poster, Pedatsur Neta
Complete degradation of 2,2',6,6'-tetrachlorobiphenyl (PCB 54) in transformer oil is achieved by ionizing radiation without degradation of the oil. Gamma irradiation of transformer oil containing PCB 54 (0.27 mg/g) with a dose of 200 kGy results in

Linear Dipole Response in a Reverberation Chamber

November 1, 1999
Author(s)
David A. Hill
A new spatial correlation function is derived for the axial electric field and is compared with the previously known spatial correlation function for the total electric field. The new correlation function is used to determine the average power received by

Long Polymerase Chain Reaction (PCR) for Variable Number of Tandem Repeats (VNTR) Analysis

November 1, 1999
Author(s)
Kristy L. Richie, M D. Goldsborough, M M. Darfler, E A. Benzinger, M L. Lovekamp, D J. Reeder, C D. O'Connell
The Polymerase Chain Reaction (PCR) has revolutionized the analysis of DNA from a variety of sources. With its sensitivity and ability to amplify degraded DNAs and small quantities of samples, coupled with fast turn-around-time, PCR is often the analytical

Measuring the Interface Stress: Silver/Nickel Interfaces

November 1, 1999
Author(s)
Daniel Josell, John E. Bonevich, I Shao, R C. Cammarata
Interface stress is a surface thermodynamics quantity associated with the reversible work of elastically straining an internal solid interface. In a multilayered thin film, the combined effect of the interface stress of each interface results in an in

Microstructure and Elastic-Constant Measurements of Two-Phase Materials

November 1, 1999
Author(s)
H M. Ledbetter, Martin Dunn
Considering two-phase materials, we focus on the relationship between microstructure and physical properties, especially elastic constants. Microstructure includes occlusion concentration, orientation, shape, size, and distribution. Isotropic materials

Migdall Responds II: More Correlated Photon Metrology History

November 1, 1999
Author(s)
Alan L. Migdall
I appreciate the comments of Mike Gruntman (Sept., page 80) concerning the history of using correlated pairs of particles(photons) to determine absolute detector quantum efficiencies. Unfortunately there is an overall misunderstanding of the technique

NIST 101. Computational Chemistry Comparison and Benchmark Database

November 1, 1999
Author(s)
Russell D. Johnson III
The CCCBDB is a collection of experimental and theoretical thermochemical properties for 580 neutral gas-phase species. The goal of the database/website is to provide a benchmark set of molecules and reactions for the evaluation of ab initio computational

NIST Programs for Calibrations in the Far Ultraviolet Spectral Region

November 1, 1999
Author(s)
Robert E. Vest, L R. Canfield, Mitchell L. Furst, R M. Graves, A D. Hamilton, L R. Hughey, Thomas B. Lucatorto, R P. Madden
The National Institute of Standards and Technology (NIST) serves the growing ultraviolet user community by providing calibration services throughout the spectral range from 2 nm to 400 nm. In this paper we describe the far ultraviolet transfer standard

NIST Realization of the Gallium Triple Point

November 1, 1999
Author(s)
Gregory F. Strouse
The gallium trip point (302.9166 K) instead of the gallium melting point (302.9146 K) is used at NIST in the realization of the International Temperature Scale of 1990 (ITS-90). Four different sources of gallium with purities of at least 99.999 995% were

Noise Behavior of Pulsed Vertical-Cavity Surface-Emitting Lasers

November 1, 1999
Author(s)
T. W. Garrison, M. Beck, David H. Christensen
We determine the pulse energy fluctuations of vertical-cavity surface-emitting lasers by measuring the number of photoelectrons produced when a laser pulse is incident upon a photodetector.

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
Displaying 49076 - 49100 of 74137