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 52051 - 52075 of 73893

A Primer on Electrical Units in the Systems International

June 1, 1998
Author(s)
Neil M. Zimmerman
I examine the dissemination of the electrical units, from basic physical laws to commercial calibrations. I discuss the important distinction between realization and representation of units, which refers back to the distinction between SI (Le Systeme

A Study of a Water-to-Water Heat Pump Using Flammable Refrigerants

June 1, 1998
Author(s)
William V. Payne, Piotr A. Domanski, J Muller
This investigation compared the performance of R22 to the performance of R290 and that of flammable zeotropic mixtures, R32/290 and R32/152a. The tests were conducted in a test apparatus specially designed to simulate a residential water-to-water heat pump

A Variational Approach to Exchange Energy Calculations in Micromagnetics

June 1, 1998
Author(s)
Michael J. Donahue
This paper presents a magnetization interpolation method for micromagnetic exchange energy calculations using a variational procedure to relax spins on a supplemental (refined) lattice. The approximations implicit in standard micromagnetic discretization

Accuracy and Traceability in Dimensional Measurements

June 1, 1998
Author(s)
James E. Potzick
Dimensional measurements of importance to microlithography include feature sizes and feature placement on photomasks and wafers, overlay eccentricities, defect and particle sizes on masks and wafers, and many others. A common element is that the object

Accurate Characteristic Impedance Measurement on Silicon

June 1, 1998
Author(s)
Dylan F. Williams, Uwe Arz, Hartmut Grabinski
This paper presents a new method that accurately determines the characteristic impedance of planar transmission lines printed on lossy dielectrics even when contact-pad capacitance and conductance are large. We demonstrate the method on a coplanar

Acoustic Methods for Transport Properties Measurements in Gases

June 1, 1998
Author(s)
Keith A. Gillis, J B. Mehl, Michael R. Moldover
Two novel acoustic resonators have been developed, one for measuring the viscosity and a second for measuring the Prandtl number of gases. For viscosity measurements, we use a double Helmholtz resonator called the Greenspan viscometer. The Greenspan

An Automated Apparatus for Measuring Sound Speeds in Hazardous Gases

June 1, 1998
Author(s)
John J. Hurly
Our laboratory has developed an automated apparatus for measuring the sound speed in hazardous gases such as those used in processing semiconductors. The sound speed (P,T) is deduced from measurements of the acoustic resonance frequencies of a gas-filled

An Equilibrium and Calorimetric Study of Some Transamination Reactions

June 1, 1998
Author(s)
Yadu D. Tewari, N Kishore, Robert N. Goldberg, T N. Luong
Apparent equilibrium constants and calorimetric enthalpies of reaction have been measured for the following enzyme-catalyzed biochemical reactions at the temperature 298.15 k:l-alanine(aq) + 2-oxoglutarate(aq) = pyruvate(aq) + L-glutamate(aq); L-tyrosine

Characterization of On-Wafer Diode Noise Sources

June 1, 1998
Author(s)
James P. Randa, Dave K. Walker, Lawrence P. Dunleavy, Robert L. Billinger, John Rice
A set of wafer probeable diode noise source transfer standards are characterized using on-wafer noise temperature methods developed recently at the National Institute of Standards and Technology (NIST). This paper reviews the methods for accurate on-wafer

Comparison of SOLR and TRL Calibrations

June 1, 1998
Author(s)
Dave K. Walker, Dylan F. Williams
We examine a short-open-load-reciprocal scattering parameter calibration in both in-line and orthogonal probe configurations. We explore its standard definitions and verify its accuracy by comparing it to a multiline thru-reflect-line calibration.

Cyclopolymerizable Monomers for Use as Acrylic Biomaterials

June 1, 1998
Author(s)
John A. Tesk, J W. Stansbury, Alan S. Litsky
Despite their many advantageous characteristics and extensive use, mixtures of methyl methacrylate monomers (MMA) and poly methyl methacrylate powders have some certain shortcomings for their use as synthetic biomaterials eg. In denture base resins

Developing a Method to Determine Linewidth Based on Counting the Atom-Spacings Across a Line

June 1, 1998
Author(s)
Richard M. Silver, Carsten P. Jensen, V W. Tsai, Joseph Fu, John S. Villarrubia, E C. Teague
We are developing the instrumentation and prototype samples at NIST to enable the counting of atom-spacings across linewidth features etched in silicon. This is an effort to allow the accurate counting of atom-spacings across a feature in a controlled

Developing Usability Tools and Techniques for Designing and Testing Web Sites

June 1, 1998
Author(s)
Jean C. Scholtz, Sharon J. Laskowski, L L. Downey
Web sites are developed by a wide variety of companies from small one or two person operations to large corportions with entire teams and departments devoted to web development work. Many of the smaller companies have no usability professionals to help
Displaying 52051 - 52075 of 73893
Was this page helpful?