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Displaying 41351 - 41375 of 74337

Development of a Quantum Based Microwave Power Measurement

June 17, 2003
Author(s)
Thomas P. Crowley, E. A. Donley, T P. Heavner, John R. Juroshek, Billy F. Riddle
An initial proof-of-concept experiment to measure microwave power based on quantum-mechanical principles is presented. Rabi oscillations between two hyperfine levels of the cesium ground state are measured and used to determine the RF magnetic field

Extraction of Conversion Matrices for P-HEMTs based on Vectorial Large-Signal Measurements

June 17, 2003
Author(s)
Alessandro Cidronali, Kuldip Gupta, Jeffrey Jargon, Kate Remley, Donald C. DeGroot, Gianfranco Manes
This paper introduces a new technique which allows us to measure the admittance conversion matrix of a two-port device, using a large signal vector network analyzer. This method is applied to extract the conversion matrix of a 0.25 um PHEMT, driven by a 4

Multisine Excitation for ACPR Measurements

June 17, 2003
Author(s)
Catherine A. Remley
We use a simlator to compare ACPR measurements of a nonlinear device excited with various multisine signals to ACPR measurements of the same device excited with a QPSK-modulated pseudorandom digital signal. We examine four common types of multisine

Sampling Oscilloscope Models and Calibrations

June 17, 2003
Author(s)
Kate Remley, Dylan Williams
We discuss the basic principles of operation of electrical sampling oscilloscopes and describe circuit models developed to design, characterize, and help explain their operation. We survey common oscilloscope calibration schemes that correct for finite

CFD Modeling of Aerosol Entry in Simplified Smoke Detector Geometries.

June 16, 2003
Author(s)
J A. Ierardi, J R. Barnett
The interaction between a ceiling jet and smoke detector is being investigated with computational fluid dynamics (CFD) modeling in order to better under aerosol entry phenomena. The CFD modeling is performed in two stages. The first stage simulates the

Light Scattering Characteristics and Size Distribution of Smoke and Nuisance Aerosols

June 16, 2003
Author(s)
D W. Weinert, Thomas Cleary, George W. Mulholland, P F. Beever
This paper presents the differential mass scattering cross section [m 2multiply by}g -1multiply by}sr -1] of various non-flaming and flaming fire generated smoke aerosols as well as nuisance aerosols created in the Fire Emulator/Detector Evaluator. These

Measurement of Soot Extinction Coefficients

June 16, 2003
Author(s)
J F. Widmann, Jiann C. Yang, George W. Mulholland, Anthony P. Hamins
An experimental apparatus used to obtain soot extinction coefficients in the infrared portion of the electromagnetic spectrum will be presented. Numerous experimental measurements of soot extinction coefficients have been previously obtained at visible

Numerical Modeling of Pool Fires Using LES and Finite Volume Method for Radiation

June 16, 2003
Author(s)
Simo A. Hostikka, Kevin B. McGrattan, Anthony Hamins
The thermal environment in small and moderate-scale pool flames is studied by Large Eddy Simulation and the Finite Volume Method for radiative transport. The spectral dependence of the local absorption coefficient is represented using a simple wide band

Genomic DNA of Nostoc Commune (Cyanobacteria) Becomes Covalently Modified During Long-Term (Decades) Desiccation But Is Protected From Oxidative Damage and Degradation

June 15, 2003
Author(s)
B Shirkey, N J. McMaster, Sue C. Smith, D J. Wright, H Rodriguez, Pawel Jaruga, M Birincioglu, R F. Helm, M Potts
Genomic DNA of Nostoc commume (Cyanobacteria) became covalently modified during decades of desiccation. Amplification of gene loci from desiccated cells required pretreatment of DNA with N-phenacylthiazolium bromide; a reagent that cleaves DNA- and protein

NIST-IMGC Comparison of Gas Flows Below 1 Liter per Minute

June 13, 2003
Author(s)
Robert F. Berg, G Cignolo
We compared the IMGC and NIST standards for small gas flows at the IMGC. The IMGC standard is a recently developed primary flow meter that extracts a large piston out of a temperature-controlled chamber. Controlling the piston's speed holds the pressure in

Phase Detrending for Measured Multisine Signals

June 13, 2003
Author(s)
Kate Remley, Dylan Williams, Dominique Schreurs, Giovanni Loglio, Cidronali Alessandro
We develop a method to detrend the phases of measured multisine signals. We find a time reference that removes the linear component of the measured phases and aligns them to their expected values to the precision specified by the user. An initial guess is

Assessment Activities at the NIST Research Library

June 11, 2003
Author(s)
Barbara P. Silcox
This presentation describes assessment activities at the Research Library of the National Institute of Standards and Technology. It is to be part of a session on Using Outcome Tracking to Plan Our Futures at the Special Libraries 2003 Annual Conference

Silicon Carbide Power MOSFET Model and Parameter Extraction Sequence

June 11, 2003
Author(s)
Ty R. McNutt, Allen R. Hefner Jr., Alan Mantooth, David W. Berning, Sei-Hyung Ryu
A compact circuit simulator model is used to describe the performance of a 2000-V, 5-A 4-H Silicon Carbide (SiC) power DiMOSFET and to perform a detailed comparison with the performance of a widely used 400-V, 5-A Silicon (Si) power MOSFET. The model's

The Role Control Center: Features and Case Studies

June 4, 2003
Author(s)
David F. Ferraiolo, Gail-Joon Ahn, Ramaswamy Chandramouli, Serban I. Gavrila
Role-based Access Control (RBAC) models have been implemented not only in self-contained resource management products such as DBMSs and Operating Systems but also in a class of products called Enterprise Security Management Systems (ESMS). ESMS products

Detector-Based Sphere Photometry for Industry

June 2, 2003
Author(s)
Yoshihiro Ohno, R S. Bergman
The Absolute Integrating Sphere Method is now used at NIST for the detector-based calibration of total luminous flux of lamps, as well as for the realization of the lumen. This method has many benefits for high-accuracy applications, allowing for

Effects of Bending in Brass Rockwell B Scale Test Blocks

June 2, 2003
Author(s)
Samuel R. Low III, J L. Fink
As part of a project to produce primary hardness reference blocks for the Rockwell B hardness scale at the National Institute of Standards and Technology (NIST), studies were conducted to observe the stability of the hardness value of the blocks over a
Displaying 41351 - 41375 of 74337
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