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Displaying 47476 - 47500 of 73969

An Improved Greenspan Acoustic Viscometer

September 1, 2000
Author(s)
J Wilhelm, Keith A. Gillis, J B. Mehl, Michael R. Moldover
We improved the Greenspan acoustic viscometer (double Helmholtz resonator) to measure the viscosity of gases at temperatures from 250 K to 400 K and at pressures up to 3.4 MPa. In anticipation of handling corrosive gases, all wetted parts of the apparatus

Applying Case-Based Reasoning to Mechanical Bearing Design

September 1, 2000
Author(s)
Xiaoli Qin, William Regli
Case-Based Reasoning (CBR) provides a promising methodology for solving many complex engineering design problems. CBR is based on the idea that past problem-solving experiences can be reused and learned from in solving new problems. This paper presents an

Artificial Neural Network Modeling for Improved On-Wafer OSLT Calibration Standards

September 1, 2000
Author(s)
Jeffrey Jargon, Kuldip Gupta, Donald C. DeGroot
We apply artificial neural networks (ANNs) to improve the modeling of on-wafer open-short-load-thru (OSLT) standards used for calibrating vector network analyzers. The ANNs are trained with measurement data obtained from a benchmark multiline thru-reflect

Assessment of Sensitivity Advances in Near-Field Raman Spectroscopy

September 1, 2000
Author(s)
Chris A. Michaels, C E. Dentinger, Lee J. Richter, D B. Chase, Richard R. Cavanagh, Stephan J. Stranick
Near-field Raman spectroscopy can be used to obtain images with both chemical specificity and the subwavelength spatial resolution of near-field scanning optical microscopy (NSOM). In the absence of signal intensification factors, such as surface

Ballistic Resistance of Personal Body Armor

September 1, 2000
Author(s)
Kathleen M. Higgins, C K. Lord
The purpose of this standard is to establish minimum performance requirements and test methods for the ballistic resistance of personal body armor intended to protect the torso against gunfire. This standard is a general revision of NIJ Standard - 0101.03

Behavior and Performance of Amorphous and Nanocrystalline Metals in Ballistic Impacts

September 1, 2000
Author(s)
L S. Magness, L Kesckes, M Chung, D Kapoor, Frank S. Biancaniello, Stephen D. Ridder
Depleted uranium alloys that exhibit adiabetic shear localization and failure resulting in a self-sharpening mecanism offer superior armor penetration capability when compared to conventional tungsten heavy alloys. Both amorphous and nanocrystalline metals

Calibrating an Active Network Node

September 1, 2000
Author(s)
Y Carlinet, V Galtier, Kevin L. Mills, Stefan D. Leigh, Andrew L. Rukhin
tive Network technology envisions deployment of virtual execution environments within network elements, so that nonhomogeneous processing can be applied to network traffic. For management purposes, each node must have a meaningful understanding of resource

Characterization of Lightpipe Radiation Thermometers for the NIST Test Bed

September 1, 2000
Author(s)
Benjamin K. Tsai, Christopher W. Meyer, Francis J. Lovas
For the past decade, lightpipe radiation theromoeters (LPRTs) have become the sensors of choice in rapid thermal processing (RTP) applications because of their non-intrusiveness and ease of use. In this paper, we discuss the importance of proper LPRT

Collision Properties of Ultracold 133 Cs Atoms

September 1, 2000
Author(s)
P J. Leo, Carl J. Williams, Paul S. Julienne
We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Vladan et al. at fields of up to 25 m T. This analysis provides the most accurate characterization of the collisional properties of ground state Cs atoms

Collisional Decomposition of SF 6

September 1, 2000
Author(s)
R. Champion, I. V. Dyakov, Yicheng Wang
Insulating gas mixtures containing SF 6 have been promoted to serve as replacements for pure SF 6 in order to reduce SF 6 atmospheric emission. It has been argued that some synergism may be achieved by choosing proper buffer gases in mixtures with SF 6

Computer Development at the National Bureau of Standards

September 1, 2000
Author(s)
Russell A. Kirsch
The first fully operational, automatic, electronic computer in the United States was built at the National Bureau of Standards. The Standards Electronic Automatic Computer (SEAC) began productive computation in May 1950. Although originally intended as an

Critical Compressibility Factors for Chain Molecules

September 1, 2000
Author(s)
L L. Lue, Daniel G. Friend, J. R. Elliott
For many equations of state for fluids composed of chain-like molecules, the compressibility factor is related to the chain number concentration only through the total monomer concentration. For these theories, we find that the critical compressibility

Curing of High-Performance Concrete for Strength-What is Sufficient?

September 1, 2000
Author(s)
Nicholas J. Carino, K W. Meeks
This paper reports the results of an exploratory study on the effects of curing duration on the variation of mortar strength with distance from the drying surface. A novel, notched cylindrical test specimen was adopted for measuring tensile strength at

Current Density Limitations of Spin Valves

September 1, 2000
Author(s)
Stephen E. Russek, Terry J. Gaffron, S. L. Burkett
As spin valve technology evolves, understanding the limitations and design constraints is a critical consideration. Choosing the correct materials combination, aspect ratio and size depends upon careful device characterization. Analysis of spin valves in

Dental Resin Composites Containing Ceramic Whiskers and Precured Glass Ionomer Particles

September 1, 2000
Author(s)
H H. Xu, F Eichmiller, Joseph M. Antonucci, Gary E. Schumacher, L K. Ives
Objectives: Glass ionomer, resin-modified glass ionomer, and compomer materials are susceptible to brittle fracture and are inadequate for use in large stress-bearing posterior restorations. The aim of this study was to use ceramic single crystal whiskers
Displaying 47476 - 47500 of 73969
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