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Displaying 44876 - 44900 of 73929

Standard Reference Material (SRM 1990) for Single Crystal Diffractometer Alignment

November 1, 2001
Author(s)
Winnie K. Wong-Ng, T Siegrist, G DeTitta, L Finger, H Evans, E Gabe, G Enright, J T. Armstrong, M Levenson, Lawrence P. Cook, C R. Hubbard
Through extensive international collaborations, a standard reference material, SRM 1990 (a set of 3500 units of Cr-doped Al2O3, or ruby sphere) for single crystal diffractometer alignment has been certified at NIST after a successful international round

Strength and Ductility of Concrete Beams Reinforced with Carbon FRP and Steel

November 1, 2001
Author(s)
Dat Duthinh, M A. Starnes
Seven concrete beams reinforced internally with steel and externally with carbon fiber-reinforced polymers (FRP) applied after the concrete had cracked were tested under four-point bending. Results show that FRP is very effective for flexural strengthening

Strength of an Interlocking FRP Connection

November 1, 2001
Author(s)
Dat Duthinh, K K. Bajpai
The strength of an interlocking fiber-reinforced polymer (FRP) connection was measured in bending, and in-plane and out-of-plane shear. This connection allows the rapid assembly of FRP panels into houses, and can be used in interlocking mode only, or

Substrate Effects on Indentation Plastic Zone Development in Thin Soft Films

November 1, 2001
Author(s)
D E. Kramer, A A. Volinsky, N R. Moody, W Gerberich
Plastic zone evolution in A1-2 wt% Si metal films on silicon and sapphire substrates was studied using nanoindentation and atomic force microscopy (AFM). AFM was used to measure the extent of plastic pileup which is a measure of the plastic zone radius in

Superfluid-to-Solid Crossover in a Rotating Bose-Einstein Condensate

November 1, 2001
Author(s)
D L. Feder, Charles W. Clark
The properties of a rotating Bose-Einstein condensate confined in a prolate cylindrically symmetric trap are explored both analytically and numerically. As the rotation frequency increases, an ever greater number of vortices are energetically favored

The Influence of a Multilayered Metallic Coating on Fatigue Crack Nucleation

November 1, 2001
Author(s)
Mark R. Stoudt, Richard E. Ricker, R C. Cammarata
A through review of the literature on fatigue crack initiation indicates that for optimum resistance to fatigue crack initiation, a surface coating needs more than just a high hardness and that a combination of properties including toughness, cyclic work

The Role of High-purity Noble Metals in Precision Thermometry

November 1, 2001
Author(s)
Dean C. Ripple, Gregory F. Strouse, Weston L. Tew
A variety of alternate calibration schemes which approximate the ITS-90 are possible when using high-purity noble metals. The high purity of the sensor materials allows the use of correlations that exist between the measured properties at fixed point

Thermal Stability of MOCVD and HVPE GaN Layers in H 2 , HCl, NH 3 and N 2

November 1, 2001
Author(s)
M A. Mastro, O M. Kryliouk, M D. Reed, T J. Anderson, Albert Davydov, Alexander J. Shapiro
This work represents a complete study of GaN annealed in H 2, HCl, NH 3 and N 2. The GaN thermal behavior was evaluated by comparison of MOCVD and HVPE samples. The MOCVD films were observed to undergo dissociative sublimation mechanism with only gaseous

Thermodynamic Assessment of the Gallium - Nitrogen System

November 1, 2001
Author(s)
Albert Davydov, William J. Boettinger, Ursula R. Kattner, T J. Anderson
Thermochemical and phase diagram data for the Ga-N system were assessed by employing the CALPHAD method. A consistent model representation of available thermodynamic properties agrees well with the critically evaluated experimental data. Thermodynamic

Thin-Film Elastic-Property Measurements With Laser-Ultrasonic SAW Spectrometry

November 1, 2001
Author(s)
Donna C. Hurley, Vinod K. Tewary, A J. Richards
We have developed laser-ultrasonic methods to evaluate the elastic properties of thin films. Our method, called SAW spectrometry, used broadband surface acoustic waves (SAWs) generated by a line-focused, pulsed laser, SAWs with frequency components up to

Tool Point Frequency Response Prediction for High-Speed Machining by RCSA

November 1, 2001
Author(s)
Tony L. Schmitz, Michael Kennedy, Matthew A. Davies
The implementation of high-speed machining for the manufacture of discrete parts requires accurate knowledge of the system dynamics. We describe the application of receptance coupling substructure analysis (RCSA) to the analytic prediction of the tool

Transmission-line Parameter Approximation for Digital Simulation

November 1, 2001
Author(s)
Dylan Williams, Christopher L. Holloway
This paper compares closed-form approximations for coplanar waveguide and microstrip transmission-line parameters to accurate measurements and full-wave calculations. We suggest improved approximations and demonstrate the limitations of our proposed and

Trial Shape-Sensitive Linewidth Measurement System

November 1, 2001
Author(s)
John S. Villarrubia, Andras Vladar, Michael T. Postek
This is a report for a project to develop a scanning electron microscope (SEM) based shape-sensitive linewidth measurement system by improving the method by improving the method by which SEM data are analyzed. We report significant developments in

Ultrafast Time-Resolved Soft X-Ray Photoelectron Spectroscopy of Dissociating Br 2

November 1, 2001
Author(s)
L Nugent-Glandorf, M Scheer, D A. Samuels, A M. Mulhisen, E R. Grant, X Yang, V M. Bierbaum, S R. Leone
The dissociation of excited state Br 2 is probed with the novel technique of ultrafast soft x-ray photoelectron spectroscopy. Excited Br 2 molecules are prepared in the dissociative 1II u state with 80 fs 400 nm pulses, and a series of photoelectron

Ultraviolet Chambers Based on Integrating Spheres for Use In Artificial Weathering

November 1, 2001
Author(s)
Joannie W. Chin, E Byrd, N Embree, Jonathan W. Martin, J D. Tate
Laboratory ultraviolet (UV) chambers are widely used to obtain weathering data for a wide range of commercial polymer products including coatings, textiles, elastomers, plastics and polymeric composites. Although numerous improvements have been made in the

Use of Legendre Transforms in Chemical Thermodynamics

November 1, 2001
Author(s)
R Alberty, J M. Barthel, E R. Cohen, Michael B. Ewing, Robert N. Goldberg, E Wilhelm
The fundamental equation of thermodynamics for the internal energy U may include terms for various types of work and involves only differentials of extensive variables. The fundamental equation for U yields intensive variables as partial derivatives of the

User's Guide to NIST Fingerprint Image Software (NFIS)

November 1, 2001
Author(s)
Michael D. Garris, Craig I. Watson, R. McCabe, Charles L. Wilson
This report documents a public domain fingerprint image software distribution developed by the National Institute of Standards and Technology (NIST) for the Federal Bureau of Investigation (FBI). The software technology contained in this distribution is a
Displaying 44876 - 44900 of 73929
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