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Search Publications

NIST Authors in Bold

Displaying 48276 - 48300 of 74141

Mechanism and Rate Constants for 1,5-Butadiene Decomposition

May 1, 2000
Author(s)
Wing Tsang, V Mokrushin
The data on the decomposition of 1,3-butadiene have been analyzed. The numerous isomerization processes that have recently been proposed as additional channels for decomposition have been considered. Energy transfer effects have been taken into account

Modeling the Microstructure and Elastic Properties of Complex Materials

May 1, 2000
Author(s)
A P. Roberts, Edward Garboczi
This document is derived from three reviewed papers by the same authors: (1)Elastic properties of a tungsten-silver composite by reconstruction and computation; (2)Elastic properties of model porous ceramics; and (3)Elastic properties of model random three

Molecular Measuring Machine Design and Measurements

May 1, 2000
Author(s)
John A. Kramar, Jay S. Jun, William B. Penzes, Fredric Scire, E C. Teague, John S. Villarrubia
We at the National Institute of Standards and Technology are building a metrology instrument called the Molecular Measuring Machine (M3) with the goal of performing nanometer-accuracy, two-dimensional, point-to-point measurements over a 50 mm by 50 mm area

Noise-Source Stability Measurements

May 1, 2000
Author(s)
James P. Randa, L. A. Terrell, Lawrence P. Dunleavy
We report results of stability tests on several noise sources for selected frequencies between 12 and 26.5 GHz. Measurements covered intervals of about 1 week and about 1 year or more. Drifts in noise temperature were typically less than the uncertainty of

Non-Arrhenius Temperature Dependence of Magnetic After Effect

May 1, 2000
Author(s)
L Swartzendruber, P Rugkwamsook, Lawrence H. Bennett, Edward Della Torre
The rate of magnetization change (magnetic aftereffect) which occurs after the magnetic field applied to a magnetic material is switched suddenly to a new value, is generally assumed to increase when the temperature is increased Deviation from this

Nonrandom Quantization Errors in Timebases

May 1, 2000
Author(s)
Gerard N. Stenbakken, D. Liu, J. A. Starzyk, Bryan C. Waltrip
Timebase distortion causes nonlinear distortion of waveforms measured by sampling instruments. When such instruments are used to measure the rms amplitude of the sampled waveforms, such distortions result in errors in the measured rms values. This paper

Polarization Correlations in Pulsed VCSELs

May 1, 2000
Author(s)
D. R. Shelly, T. W. Garrison, M. Beck, David H. Christensen
We have measured the correlations between the two orthogonal linearly polarized outputs of a pulsed vertical-cavity, surface-emitting laser and found them to be dependent on the number of lasing modes.

Presenting Search Results: Design, Visualization, and Evaluation

May 1, 2000
Author(s)
John V. Cugini
A number of projects within the National Institute of Standards and Technology (NIST) have addressed the visual presentation and evaluation of search results. Within the design space for this problem, we distinguish between the logical structure imposed on

Recent Developments in BIPM Voltage Standard Comparisons

May 1, 2000
Author(s)
D. Reymann, Thomas J. Witt, P. Vrabcek, Yi-hua D. Tang, Clark A. Hamilton, A. S. Katkov, Blaise Jeanneret, O. Power
The BIPM carries out a number of comparisons of DC voltage standards with National Metrology Institutes. These take the form of on-site comparisons of Josephson standards or bilateral comparisons using traveling standards based on Zener diodes. This paper

Reconstruction and Preliminary Tests of the NIST Electronic Kilogram Experiment

May 1, 2000
Author(s)
Richard L. Steiner, David B. Newell, J. Schwarz, Edwin R. Williams, Ruimin Liu
The NIST electronic kilogram experiment is being completely rebuilt into a vaccum chamber within a specially designed laboratory room. Major renovations include reference mass positioning equipment, structural alignment flexures, and a redesigned inductive

Report on the CCEM Comparison of 10 pF Capacitance Standards

May 1, 2000
Author(s)
Anne-Marie Jeffery
This paper describes the recent Comite Consultatif d'Electricite et Magnetisme (CCEM) comparison of 10 pF capacitors. The comparison of electrical standards between the regional metrology organization (RMOs) will establish the relationship of the

RF Material Characterization Using a Large-Diameter (76.8 mm) Coaxial Air Line

May 1, 2000
Author(s)
Chriss A. Jones, John H. Grosvenor Jr, Claude Weil
We report the development of a 76.84 mm (3.025 in) diameter coaxial air line system whose purpose is to measure the dielectric and magnetic properties of bulk dielectric and ferrite materials over a frequency range of approximately 0.3 - 1500 MHZ. We

Role of Competitive Interactions in Growth Rate Trends of Subtilsin s88 Crystals

May 1, 2000
Author(s)
D Asthagirl, A Lenhoff, David Travis Gallagher
An orthorhombic crystal form of subtilisin BPN' variant s88 exhibits a systematic variation in growth rates of its three unique faces, resulting in pronounced variations in crystal morphology as a function of the ionic strength. We have sought to explain

Rotating-Wheel Braille Display for Continuous Refreshable Braille

May 1, 2000
Author(s)
John W. Roberts, Oliver T. Slattery, D W. Kardos
The increasingly pervasive influence of information technology on daily life makes accessibility a higher priority than ever before. Millions of blind and visually impaired people in the US (and far higher numbers worldwide) need some form of non-visual
Displaying 48276 - 48300 of 74141
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