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Displaying 47901 - 47925 of 73929

Lattice-Statics Model for Edge Dislocations in Crystals

June 1, 2000
Author(s)
Vinod K. Tewary
A lattice statics Green's function method is described for modeling an edge dislocation in a crystal lattice. The edge dislocation is created by intoducing a half plane of vacancies as in Volterra's condtruction. The defect space is decomposed into a part

Linewidth Measurement Intercomparison on a BESOI Sample

June 1, 2000
Author(s)
John S. Villarrubia, Andras Vladar, J R. Lowney, Michael T. Postek, Richard A. Allen, Michael W. Cresswell, Rathindra Ghoshtagore
The effect of the instrument on the measurement must be known in order to generate an accurate linewidth measurement. Although instrument models exist for a variety of techniques, how does one assess the accuracy of these models? Intercomparisons between

Modeling of Stable and Unstable Polarization Switching

June 1, 2000
Author(s)
H Kessler, Lin-Sien H. Lum, H Balke
We examine the stability of polarization switching in polyscrystalline ferroelectric/ferroelastic materials subject to continuous electromechanical loading. In case of unstable switching, a finite change of remanent polarization or strain results from an

Multilevel Structure of Reinforcing Silica and Carbon

June 1, 2000
Author(s)
D W. Schaefer, T Rieker, M M. Agamalian, J S. Lin, Daniel A. Fischer, S Sukumaran, C I. Chen, G Beaucage, C Herd, J Ivie
We study the structure of colloidal silica and carbon on length scales from 0.25 -1 7 using x-ray, neutron and light scattering. These materials consist of primary particles of the order of 100 , aggregated into micrometer-sized aggregates that in turn are

Multiport Noise Characterization and Differential Amplifiers

June 1, 2000
Author(s)
James P. Randa
I address the issue of the definition and measurement of noise figure and parameters to characterize multiport devices, particularly differential amplifiers. A parameterization in terms of the noise matrix appears to be the most practical. The noise figure

New Low-Index Liquid Refractive Index Standard: SRM 1922

June 1, 2000
Author(s)
Jennifer R. Verkouteren, Stefan D. Leigh
A new standard for the calibration of refractometers has been developed. Standard Reference Material (SRM) 1922 is a mineral oil with a refractive index n D=1.46945 at 20 C, which is within the range of the Brix scale (% sucrose). The change in index with

On Weakly Analytic and Faithfully Convex Functions in Convex Programming

June 1, 2000
Author(s)
G P. McCormick, Christoph J. Witzgall
Weakly-analytic convex, faithfully convex, and self-concordant functions are considered, and their relationships described. The purpose of the report is to state and provide complete proofs of results that illustrate circumstances under which weak

Optical Fiber Power Meter Calibrations at NIST

June 1, 2000
Author(s)
Igor Vayshenker, Xiaoyu X. Li, David J. Livigni, Thomas Scott, Christopher L. Cromer
NIST has established measurement services for the calibration of optical fiber power meters at the three nominal wavelengths of 850, 1300, and 1550 nm using either collimated beam or optical fiber/connector configurations. This paper describes the

Parallel Genetic Programming

June 1, 2000
Author(s)
John G. Hagedorn, J E. Devaney
This project is developing a generic Genetic Programming system that is inherently parallel. Genetic Programming uses Darwinian selection and reproduction to evolve a solution to a problem, where individuals are represented by computer programs. A user

Phase-Tailoring Molecular Wave Packets to Time-Shift Their Dynamics

June 1, 2000
Author(s)
Z Amitay, J B. Ballard, H U. Stauffer, S R. Leone
Time-shifting (up to a global arbitrary phase) of the dynamics of molecular wave packets, i.e., |dielectric flux}(t)> -> | dielectric flux} (t-t shift)>, is demonstrated using a high degree of state-selective coherent phase control with shaped femtosecond

Realistic Sampling-Circuit Model for a Nose-to-Nose Simulation

June 1, 2000
Author(s)
Catherine A. Remley, Dylan F. Williams, Donald C. DeGroot
We extend previously developed oscilloscope sampler models to include realistic circuit characteristics and use these models to investigate the nose-to-nose calibration technique.

Recent Progress in Nanoscale Indentation of Polymers Using the AFM

June 1, 2000
Author(s)
Mark R. VanLandingham, John S. Villarrubia, G F. Meyers
Regardless of the type of test, reliable indentation measurements require knowledge of the shape of the indenter tip. For indentation measurements involving sub-micrometer scale contacts, accurate knowledge of the tip shape can be difficult to achieve. In
Displaying 47901 - 47925 of 73929
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