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Displaying 49751 - 49775 of 74220

Linux-Based Clusters at the National Institute of Standards and Technology

June 1, 1999
Author(s)
Wayne J. Salamon, Alan Mink
The Scalable Parallel Systems and Applications Group at the National Institute of Standards and Technology (NIST) has been experimenting with Linux-based clusters of computers. These clusters are used for both the running of computationally intensive

Long Term Stability of YBCO-Based Josephson Junctions

June 1, 1999
Author(s)
Leila R. Vale, Ronald H. Ono, J. Talvacchio, M. G. Forrester, B. D. Hunt, M. S. DiTorio, Ki Youl Yang, S. Yoshizumi
We report on a study of long term aging in three different types of Yba 2Cu 3O 7-x Josephson junctions. Junction aging will affect the choices made in integrating this technology with actual applications. The junction types used in this study are (a) Co

Lowering the Limit of Detection in High Spatial Resolution Electron Beam Microanalysis With the Microcalorimeter Energy Dispersive X-Ray Spectrometer

June 1, 1999
Author(s)
Dale E. Newbury, David A. Wollman, Kent D. Irwin, Gene C. Hilton, John M. Martinis
Low-beam-energy x-ray microanalysis with the field-emission-gun scanning electron microscope suffers limitations due to physical factors of x-ray generation. Instrumental limitations are imposed by the poor resolution of the conventional semiconductor

Mean-Field-Scaling in Lattice Boltzmann Fluid Mixtures

June 1, 1999
Author(s)
Nicos Martys, Jack F. Douglas
Basic equilibrium properties of Lattice Boltzmann (LB) fluid mixtures (coexistence curve, surface tension, and interfacial profile) are calculated to characterize the critical phenomena occurring in these model liquids and to establish a reduced variable

Measurement Traceability to NIST Standard Rockwell Diamond Indenters

June 1, 1999
Author(s)
Jun-Feng Song
A metrology-based Rockwell hardness scale is established by a standard machine and a standard diamond indenter. Both must be established through force and dimensional metrology with acceptably small measurement uncertainties. In 1994, NIST developed a

Measurement Uncertainity and Noise in Nanometrology

June 1, 1999
Author(s)
James E. Potzick
The measurement of feature sizes on integrated circuit photomasks and wafers is an economically important and technically challenging application of nanometrology. The displacement measuring laser heterodyne interferometer is a popular tool in such

Microleakage of a Consolidted Silver Direct Filling Material

June 1, 1999
Author(s)
F Eichmiller, Anthony A. Giuseppetti, Kathleen M. Hoffman, D R. Brajdic, V Miksch, J A. Delorey-Lytle
Microleakage of an experimental direct filling materisl comprised of a chemically precipitated silver powder that had been surface treated with a dilute acid to promote cold welding upon consolidation was evaluated. Microleakage was compared to both

Molecular Models of Water. I. Derivation and Description

June 1, 1999
Author(s)
A Wallqvist, Raymond D. Mountain
Molecular level computer simulations based on molecular dynamics and Monte Carlo methods have become widely used techniques in the study and modeling of aqueous systems. These simulations of water involve a few hundred to a few thousand water molecules at

Nanoscale Chemical Imaging With Scanning Near-Field Infrared Microscopy

June 1, 1999
Author(s)
Chris A. Michaels, Stephan J. Stranick, Lee J. Richter, Richard R. Cavanagh
The development of a near-field microscope that utilizes infrared absorption as the optical contrast mechanism will be described. This instrument couples the nanoscale spatial resolution of a scanning probe microscope with the chemical specificity of

Neutron Powder Diffraction of Carbon-Coated FeCo Alloy Nanoparticles

June 1, 1999
Author(s)
J H. Scott, K Chowdary, Z Turgut, S. A. Majetich, M E. McHenry
Neutron powder diffraction is used to study the order-disorder transformation in carbon-coated Fe xCo 1-x nanoparticles produced using a radio frequency (RF) plasma torch. The nanoparticles, nominally Fe 50Co 50, are produced from alloy powder and

Non-Uniquenes of the ITS-90 From 13.8033 K to 24.5561 K

June 1, 1999
Author(s)
Christopher W. Meyer, Gregory F. Strouse, Weston L. Tew
The International Temperature Scale of 1990 (ITS-90) is defined in the region 3.0 K to 24.5561 K by an interpolating constant volume gas thermometer (ICVGT) that is calibrated at three specified fixed points. From 13.8033 K to 1234.93 K the ITS-90 is

Observation of Conical Emission From a Single Self-Trapped Beam

June 1, 1999
Author(s)
B D. Paul, Marla L. Dowell, Alan Gallagher, J W. Cooper
We report observations of conical emission from a pulsed laser beam with incident laser power, detuning, and beam diameter matched to a range of single, steady-state filaments. The beam thus propagates with nearly constant diameter through 5 cm of

Opening Up to Standardization

June 1, 1999
Author(s)
Barbara L. Goldstein, J. Cartwright
Today's electronics manufacturers are expected to reduce their time-to-market cycles and lower total costs simultaneously. Product development cycles and volume ramp-up times are rapid, and corresponding end-of-life production is dramatic. This environment

Operating Conditions for a Pulse-Quantized AC and DC Bipolar Voltage Source

June 1, 1999
Author(s)
Samuel Benz, Charles J. Burroughs, Todd E. Harvey, Clark A. Hamilton
We have developed an accurate ac and dc bipolar voltage source based on the quantized pulses of Josephson junctions. A factor-of-6 increase in output voltage over previous unipolar waveforms is achieved by generating bipolar waveforms where arrays of

Operating Margins for a Superconducting Voltage Waveform Synthesizer

June 1, 1999
Author(s)
Samuel Benz, Clark A. Hamilton, Charles J. Burroughs
Operating margins for biolar superconducting voltage waveform synthesizer were measured. Current ranges were determined for 101 equally spaced dc voltage steps between - 18.6 and + 18.6 mV. The measured voltages of these steps deviated from the expected

Optical Linewidth Models: Then and Now

June 1, 1999
Author(s)
Robert D. Larrabee, Richard M. Silver, M P. Davidson
In the late 1970's, Dr. Diana Nyyssonen demonstrated that NIST could optically calibrate photomask linewidth standards that were narrower than the classical resolution limit of a conventional bright-field microscope. She equated the known position of the
Displaying 49751 - 49775 of 74220