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Displaying 47801 - 47825 of 73830

Ideal Gases in Time-Dependent Traps

June 1, 2000
Author(s)
G M. Bruun, Charles W. Clark
We investigate theoretically the properties of an ideal trapped gas in a time-dependent harmonic potential. Using a scaling formalism, we are able to present exact analytical results for two important classes of experiments: free expansion of the gas upon

In-Situ Observation of Small-Angle X-Ray Scattering by Dislocations

June 1, 2000
Author(s)
Lyle E. Levine, Gabrielle G. Long, R Thomson
Ultra-small-angle X-ray scattering by dislocations in single-crystal aluminum has been observed in situ as a function of plastic deformation. The scattering is observed to be strongly dependent upon sample orientation, with single dislocations, dislocation

Intelligent Control for Unmanned Vehicles

June 1, 2000
Author(s)
Karl Murphy, Marilyn N. Abrams, Stephen B. Balakirsky, David Coombs, Tsai Hong Hong, Steven Legowik, Tommy Chang, Alberto Lacaze
Mobility, Unmanned Systems, Vision, Robotics & Intelligent Systems

Interacting Atoms Under Strong Quantum Confinement

June 1, 2000
Author(s)
Eite Tiesinga, Carl J. Williams, F H. Mies, Paul S. Julienne
We calculate the energy level shifts of a tightly-confined trapped alkali atom in the presence of a second trapped atom. A complete microscopic description of the interaction energy between the two atoms is used. This allows us to study tightly-confined

Is 'Implementation Implies Specification' Enough?

June 1, 2000
Author(s)
Paul E. Black
An implementation is typically checked against a specification by proving that the implementation implies the specification. This ensures that the implementation only has behaviors allowed by the specification. However, this does not require the

Is a Production Level Scanning Electron Microscope Linewidth Standard Possible?

June 1, 2000
Author(s)
Michael T. Postek, Andras Vladar, John S. Villarrubia
Metrology will remain a pricipal enabler for the development and manufacture of future generations of semiconductor devices. With the potential of 130 nm and 100 nm linewidths and high aspect ratio structures, the scanning electron microscope (SEM) remains

Is a Production-Level Scanning Electron Microscope Linewidth Standard Possible?

June 1, 2000
Author(s)
Michael T. Postek, Andras Vladar, John S. Villarrubia
Metrology will remain a principal enabler for the development and manufacture of future generations of semiconductor devices. With the potential of 130 and l00-nanometer linewidths and high aspect ratio structures, the scanning electron microscope (SEM)

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
Displaying 47801 - 47825 of 73830
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