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Displaying 50626 - 50650 of 74160

Polycapillary X-Ray Optic Spectral Gain and Transmission

April 1, 1999
Author(s)
J E. Gormley, Eric B. Steel, Q Xiao, Terrence J. Jach
Polycapillary x-ray optics are gaining increased attention as their transmission characteristics and manufacturing difficulties are better understood. This paper reports experimental results obtained with an optic that was designed for use with both Mo KΑ

Primary Acoustic Thermometer for Use Up to 800 K

April 1, 1999
Author(s)
Dean C. Ripple, Dana R. Defibaugh, Keith A. Gillis, Michael R. Moldover
Primary acoustic thermometers determine the thermodynamic temperature of a monatomic gas from measurements of the speed of sound in the gas. Here, we describe the design and construction of an acoustic thermometer designed to operate at temperatures up to

Primary Acoustic Thermometry From 217 K to 303 K

April 1, 1999
Author(s)
Michael R. Moldover, S J. Boyes, A R. Goodwin, Christopher W. Meyer
We report new values for the difference (T T 90) between Kelvin thermodynamic temperatures T and ITS-90, the International Temperature Scale of 1990. The new data span the range 217 K {less then or equal to} T 303 K with standard uncertainties of 0.6 mK. A

Programmable 1 V DC Voltage Standard

April 1, 1999
Author(s)
Charles J. Burroughs, Samuel Benz, Clark A. Hamilton, Todd E. Harvey
We have developed a Josephson voltage standard that produces intrinsically stable voltages that are programmable of 32 768 SNS (superconductor-normal-superconductor) Josephson junctions. The output can source or sink up to 2 mA and thus has high noise

Second Process Specification Language (PSL) Roundtable

April 1, 1999
Author(s)
Craig I. Schlenoff
This report describes the Second Process Specification Language (PSL) Roundtable that was held at the University of Maryland, University College on January 13-14, 1999. The Roundtable brought together vendors, endusers, and researchers from different

Size Effect for Specific Energy in Grinding of Silicon Nitride

April 1, 1999
Author(s)
T W. Hwang, Christopher J. Evans, S Malkin
An investigation is reported of the ?size effect? for specific energy in grinding of silicon nitride. Experimental measurements over a wide range of operating parameters using two different grit size diamond wheels show an increase in specific energy as

Specimen Preparation for Scanning Electron Microscopy

April 1, 1999
Author(s)
Paul E. Stutzman, J R. Clifton
Microscopy plays an important role in the examination of cementitious materials. Optical and electron-optical techniques allow examination of microstructural details with sub-micrometer definition. The increased application of scanning electron microscopy

Stabilization and Frequency Measurement of the I 2 -Stabilized Nd: YAG Laser

April 1, 1999
Author(s)
D S. Hall, L -. Ma, M S. Taubman, B Tiemann, F L. Hong, O Pfister, J Ye
We report improved stabilization results for and progress toward a more accurate frequency measurement of the 532 nm iodine-stabilized system based on a frequency-doubled Nd: YAG ring laser. We confirm the CCL-adopted frequency well within its stated

Temperature Imaging Measurements With a Two Wavelength Imaging Pyrometer

April 1, 1999
Author(s)
J E. Craig, D Lee, R A. Parker, Frank S. Biancaniello, Stephen D. Ridder
An innovative two-wavelength, imaging pyrometer with analysis software provides a method to monitor process uniformity, improve quality and reduce cost in advanced materials processing techniques. The design has achieved high imaging quality and the system

The Importance of Importance Sampling

April 1, 1999
Author(s)
Isabel M. Beichl, F Sullivan
This is a tutorial article on Monte Carlo technique of importance sampling that has been under-appreciated. We recently used it with great success and so we share our insights with our readers. Importance sampling is a form of Monte Carlo sampling designed

The Kilogram: Last remaining artifact

April 1, 1999
Author(s)
Zeina J. Kubarych
The unit of mass, the kilogram, is the last remaining basic unit defined by an artifact. Worldwide efforts are underway to replace the artifact-based definition with invariant alternatives. This paper describes briefly the history of the kilogram, the

The Molar Volume of Silicon: Discrepancies and Limitations

April 1, 1999
Author(s)
R Deslattes, Ernest G. Kessler
We offer a new representation of the current silicon molar volume discrepancy by attending to a previously incorrect accounting of the early work at the National Bureau of Standards (NBS). Removal of a poorly documented correction to the NBS density scale

Thermodynamics of Enzyme-Catalyzed Reactions: Part 6. 1999 Update

April 1, 1999
Author(s)
Robert N. Goldberg
This review serves to update previously published evaluations of equilibrium constants and enthalpy changes for enzyme-catalyzed reactions. For each reaction the following information is given: the reference for the data; the reaction studied; the name of
Displaying 50626 - 50650 of 74160
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