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NIST Authors in Bold

Displaying 36851 - 36875 of 73697

Measurement of Second Order Susceptibilities of GaN and AlGaN

March 1, 2005
Author(s)
Norman Sanford, Albert Davydov, Denis V. Tsvetkov, Vladimir A. Dmitriev, Stacia Keller, Umesh Mishra, Steven P. DenBaars, S S. Park, J H. Han
Rotational Maker fringes, scaled with respect to χ 11 (2) of crystalline quartz, were used to determine the nonlinear optical coefficients χ 31 (2) and χ 33 (2) for samples of thin Al xGa 1-xN films and a bulk free-standing GaN platelet. The Al xGa 1-xN

Measurement of Weak Signals Using a Communications Receiver System

March 1, 2005
Author(s)
Marc Rutschlin, Kate Remley, Robert T. Johnk, Dylan Williams, Galen H. Koepke
We describe the calibration of an inexpensive, reliable system for use in weak-signal detection. The calibration procedure described allows the conversion of signals measured with the communications receiver system-which is based on a standard

Measurement of Workability of Fresh Concrete Using a Mixing Truck

March 1, 2005
Author(s)
S Amziane, Chiara C. Ferraris, E Koehler
The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete mixtures with

Mitochondrial DNA Typing Screens With Control Region and Coding Region SNPs

March 1, 2005
Author(s)
Margaret C. Kline, Peter M. Vallone, Janette W. Redman, David L. Duewer, C D. Calloway, John M. Butler
Mitochondrial DNA (mtDNA) analysis has found an important niche in forensic DNA typing. It is used with highly degraded samples or low-copy number materials such as might be found from shed hair or bones exposed to severe environmental conditions. The

Modeling the IAQ Impact of HHI Interventions in Inner-City Housing

March 1, 2005
Author(s)
Steven J. Emmerich, Cynthia H. Reed
The U.S. Department of Housing and Urban Development (HUD) has identified a need to improve urban housing conditions to protect children s health through its Healthy Homes Initiative (HHI). One critical area within this program is to address a wide range

NIST Optoelectronic Measurements for Fiber Optic Applications

March 1, 2005
Author(s)
Kent B. Rochford, Paul D. Hale, Nathan R. Newbury
We describe current measurement capabilities as well as research focused on two areas: improving temporal and frequency response characterization of detectors and instrumentation using electro-optic sampling, and improving wavelength metrology using

Ontology-based Exchange of Product Data Semantics

March 1, 2005
Author(s)
Lalit Patil, D Dutta, Ram D. Sriram
An increasing trend toward product development in a collaborative environment has resulted in the use of various software tools to enhance the product design. This requires a meaningful representation and exchange of product data semantics across different

Optimized Arbitrary Wireless Device Arrays for Emergency Response Communications

March 1, 2005
Author(s)
William F. Young, Edward Kuester, Christopher L. Holloway
Wireless communications are essential to emergency responders. Unfortunately, a typical emergency response scenario involves communication into and within structures, which severely interfere with or completely block the radio frequency channel. In this

Photoreflectance Study of the Electronic Structure of Si-Doped InyGa 1-y As 1-x N x Films With x 0.012

March 1, 2005
Author(s)
Youn S. Kang, Lawrence H. Robins, Anthony Birdwell, Alexander J. Shapiro, W. R. Thurber, Mark D. Vaudin, M M. Fahmi, D Bryson, S N. Mohammad
The electronic structure of Si-doped InyGa1-yAs1-xNx films on GaAs substrates, grown by nitrogen-plasma-assisted MBE, was examined by photoreflectance (PR) spectroscopy at temperatures between20 K and 300 K. The measured critical-point energies were

Precise Determination of 6 Li Cold Collision Parameters by Radio-Frequency Spectroscopy on Weakly Bound Molecules

March 1, 2005
Author(s)
M Bartenstein, A Altmeyer, S Riedl, R Geursen, S Jochim, C Chin, J Hecker Denschlag, R Grimm, Andrea Simoni, Eite Tiesinga, Carl J. Williams, Paul S. Julienne
Radio-frequency spectroscopy on weakly bound 6Li_2 molecules determines to high precision the molecular binding energies and the energy splitting between molecular states. By fitting the measurement to a multi-channel quantum scattering model, we determine

Propagating Waves of Network Formation Induced by Light

March 1, 2005
Author(s)
J Cabral, Jack F. Douglas
The exposure of a photopolymerizable liquid to ultraviolet (UV) radiation leads to a propagating wavefront of network formation that invades the unpolymerized material from the illuminated surface of the photosensitive material. We theoretically describe

Protocol Modifications for the DNS Security Extensions RFC 4035

March 1, 2005
Author(s)
R Arends, R Austein, M Larson, Daniel Massey, Scott W. Rose
This document is part of a family of documents that describe the DNS Security Extensions (DNSSEC). The DNS Security Extensions are a collection of new resource records and protocol modifications that add data origin authentication and data integrity to the

R-22 Replacement Status (in Portuguese) Part 1 and Part 2

March 1, 2005
Author(s)
J M. Calm, Piotr A. Domanski
Since its initial recognition in 1928 and commercialization in 1936, R-22 has been applied in systems ranging from the smallest window air conditioners to the largest chillers and heat pumps, including those for district cooling and heating. Individual

Rapid Fixation of Methylene Chloride By a Macrocyclic Amine

March 1, 2005
Author(s)
J C. Lee, Keith J. Stanger, Bruce C. Noll, Carlos A. Gonzalez, M Marquez, Bradley D. Smith
A simple macrocyclic amine is alkylated by methylene chloride to give a quaternary ammonium chloride salt. When methylene chloride is the solvent, the reaction exhibits pseudo first order kinetics, and the reaction half-life at 25.0 C is 2.0 minutes. The

Rate Constants for Reactions of Phenoxyl Radicals in Solution

March 1, 2005
Author(s)
Pedatsur Neta, J Grodkowski
Absolute rate constants for reactions of phenoxyl radicals in solution have been compiled and evaluated from the literature. Rate constants are included for phenoxyl radicals bearing various substituents, including semiquinone radicals and radical ions, as

Resource Records for the DNS Security Extensions, RFC 4034

March 1, 2005
Author(s)
R Arends, R Austein, M Larson, Daniel Massey, Scott W. Rose
This document is part of a family of documents that describe the DNS Security Extensions (DNSSEC). The DNS Security Extensions are a collection of resource records and protocol modifications that provide source authentication for the DNS. This document

Second Harmonic Magneto-Resistive Imaging to Authenticate and Recover Data from Magnetic Storage Media

March 1, 2005
Author(s)
David P. Pappas, Alexey Nazarov, D Stevenson, Steven Voran, Mike E. Read, Erin M. Gormley, James Cash, Ken Marr, James Ryan
A scanning magneto-resistive (MR) microscope was developed for high resolution imaging of magnetic tapes and digital media. Second harmonic detection was used to remove thermal anomalies. We were able to image sufficient lengths of tape for authentication
Displaying 36851 - 36875 of 73697
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