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Displaying 40976 - 41000 of 73970

Direct Observation of De-Mixing in a Ceramic Metal-Halide Arc Lamp

June 18, 2003
Author(s)
John J. Curry, H G. Adler, S Shastri, W -. Lee
De-mixing of additives in a vertically-operated DyI 3-CsI-Hg ceramic metal halide arc lamp has been observed by examining the ratios of absolute elemental densities as a function of position. As the elemental densities have been obtained directly by x-ray

Durability Gap Analysis for Fiber-Reinforced Polymer Composites in Civil Infrastructure

June 18, 2003
Author(s)
V M. Karbhari, Donald L. Hunston, B Benmokrane, T Juska, Roy S. Morgan, J Lesko, U Sorathia, D R. Reynaud
The lack of a comprehensive, validated, and easily accessible data base for the durability of fiber-reinforced polymer _FRP_composites as related to civil infrastructure applications has been identified as a critical barrier to widespread acceptance of

Morphotropic Phase Boundary Perovskites, High Strain Piezoelectrics, and Dielectric Ceramics

June 18, 2003
Author(s)
R Guo, Winnie Wong-Ng, D Viehland, C M. Wu, K M. Nair, A S. Bhalla, D Suvorov, S I. Hirano
The content of this Ceramic Transactions volume comprises the proceedings of the Symposium on Dielectric Materials andMultilayer Electronic Devices and the Symposium on Morphotropic Phase Boundary Phenomena and Perovskite Materials,held April 28 - May 1

Velocity Fluctuations in a Steadily Sheared Model Foam

June 18, 2003
Author(s)
I K. Ono, S Tewari, Stephen A. Langer, A J. Liu
Numerical simulations are conducted to calculate velocity fluctuations in a simple two-dimensional model of foam under steady shear. The width of the velocity distribution increases sublinearly with the shear rate, indicating that velocity fluctuations are

An Optimal Multiline TRL Calibration Algorithm

June 17, 2003
Author(s)
Dylan Williams, Jack Wang, Uwe Arz
We examine the performance of two on-wafer multiline TRL calibration algorithms, the popular multiline TRL algorithm implemented in the MultiCal software package and a newly implemented iterative algorithm designed to give optimal results in the presence

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
Displaying 40976 - 41000 of 73970
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