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Displaying 28801 - 28825 of 74303

A Mean-Field Model of Extrinsic Line Broadening in Ferromagnetic Resonance

October 16, 2008
Author(s)
Robert D. McMichael
A model of ferromagnetic resonance in inhomogeneous films is described that includes interactions in a mean-field approximation. The mean-field model yields linewidth values that span the range from intrinsic linewidth for strong interactions to fully

A merged-beams energy-loss technique for electron-ion excitation: Absolute total cross sections for o 5+ (2s> 2p)

October 16, 2008
Author(s)
E W. Bell, X Q. Guo, J L. Forand, K Rinn, D R. Swenson, J S. Thompson, G H. Dunn, M E. Bannister, D C. Gregory, Ray A. Phaneuf, A C. Smith, A Muller, C A. Timmer, E K. Wahlin, B D. DePaola, D S. Belic
A merged-beams electron-energy-loss technique is described by which absolute cross sections can be measured for near-threshold electro-impact excitation of multiply charged ions. Results are reported here for absolute total electron-impact excitation cross

A Method to Quantify Uncertainty Due to Bias in Chemical Analyses

October 16, 2008
Author(s)
Raghu N. Kacker
A widely accepted approach to assure that the certified property of a chemical reference material is independent of the method of analysis is to analyze by two or more judiciously chosen methods. The statistical problem then is to determine the consensus

A Modified Wigner's Inequality for Secure Quantum Key Distribution

October 16, 2008
Author(s)
Stefania Castelletto, Ivo P. Degiovanni, M L. Rastello
In this letter we discuss the insecurity with present implementations of the Ekert protocol for quantum-key distribution based on the Wigner Inequality. We propose a modified version of this inequality which guarantees safe quantum-key distribution.

A Multi-Sample Melt Micro-Rheometer

October 16, 2008
Author(s)
Anthony J. Bur, Kalman Migler
A slit micro-rheometer that is used for simultaneous measurement of melt viscosities of four samples has been developed. Sample size is less than 100 mg. The driving force for the rheometer is gas pressure from a nitrogen tank that forces polymer melt into

A New Chemical Reactor for Protein Crystal Growth

October 16, 2008
Author(s)
David Travis Gallagher, C Stover, J Moses, D Charlton, E Steinberg, L Arnowitz
Current rapid advances in the genomic and biochemical sciences provide impetus for finding improved ways of crystallizing proteins for structure determination. A new dialysis-based reactor for protein crystal growth is described. The device utilizes motor

A New International Evaluation of the Neutron Cross Section Standards

October 16, 2008
Author(s)
Allan D. Carlson
The measurements of most neutron cross sections are made relative to neutron cross section standards. The last complete evaluation ofthe standards, which was for ENDF/B-VI, took place almost 15 years ago. The cross section standards produced for the ENDF/B

A Standard Reporting Format for Summative Usability Evalutations

October 16, 2008
Author(s)
Jean C. Scholtz, Emile L. Morse
Poor usability is an uncontrolled source of overhead, caused by the need for users to correct errors and continually re-learn complex user interfaces. Software that is measurably usable reduces errors, reduces training costs, and reduces maintenance costs

A Statistical Connection Between Dislocations and Mechanical Properties

October 16, 2008
Author(s)
Lyle E. Levine, R M. Thomson
The extreme complexity of the dislocation-based processes that underlie plastic deformation are in marked contrast to the relatively simple behavior observed macroscopically. The simplification arises because a deforming metal can be described as a self

A Systematically-Generated, Pressure-Dependent Mechanism for High-Conversion Ethane Pyrolysis. Part II: Radical Disproportionations, Missing Reaction Families, and the Consequences of Pressure-Dependence

October 16, 2008
Author(s)
D M. Matheu, J M. Grenda
Part I of this work systematically developed a pressure-dependent reaction mechanism for the high-conversion pyrolysis of ethane [1], as studied experimentally by Glasier and Pacey [2]. By combining conventional equilibrium, sensitivity, and reaction

Accoustic Studies of Composite-Material Interfaces

October 16, 2008
Author(s)
H M. Ledbetter
We review six recent acoustic studies of composite-material interfaces. Measured physical properties are either elastic constants (sound velocities resonance frequencies) or internal frictions. The materials considered include (1) glass fiber/epoxy, (2)

Accuracy Issues in Chemical and Dimensional Metrology in the SEM and TEM

October 16, 2008
Author(s)
J H. Scott
In this work computer simulations are used to understand systematic errors and accuracy concerns in both dimensional and chemical metrology in the scanning electron microscope (SEM) and transmission electron microscope (TEM).Multislice high-resolution TEM

Accurate Determination of High Energy Gamma-Ray Standards

October 16, 2008
Author(s)
Ernest G. Kessler Jr., Maynard S. Dewey, R Deslattes, Albert Henins, H G. Borner, M Jentschel, H Lehmann
The extension of accurate crystal diffraction spectroscopy to the 2 to 6 MeV region is described. Gamma-ray standards with a relative uncertainty of (2 to 5)x10 -7 are obtained by measuring the small diffraction angles (a few tenths of a degree) through
Displaying 28801 - 28825 of 74303