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Measurement Of Exclusive Ω Electroproduction At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti Aug 2000

Measurement Of Exclusive Ω Electroproduction At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

The exclusive electroproduction of ω mesons, ep → e ω p, has been studied in the kinematic range 3 < Q2 < 20 GeV2, 40 < W < 120 GeV and |t| < 0.6 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb-1. The ω mesons were identified via the decay ω → π+ π- π0. The exclusive cross section in the above kinematic region is σ(ep) → e ω p = 0.108 ± 0.014 (stat.) ± 0.026(syst.) nb. The reaction ep → e φ p, φ → π+ π- π0, has also been measured. The cross sections, as well as the ratios σ γ·p → ωp/σ γ · p → p0p and σ γ · p → ωp/σγ·p → φp, are presented as a function of W and Q2. Thus, for the first time, the properties of ω electroproduction can be compared to those of p0,φ and J/ψ electroproduction at high W. (C) 2000 Elsevier Science B.V.

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Measurement Of The Proton Structure Function F2 At Very Low Q2 At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi Aug 2000

Measurement Of The Proton Structure Function F2 At Very Low Q2 At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti, G. Levi

Faculty Publications

A measurement of the proton structure function F2(x, Q2) is presented in the kinematic range 0.045 GeV2 < Q2 < 0.65 GeV2 and 6 · 10-7 < x < 1 · 10-3. The results were obtained using a data sample corresponding to an integrated luminosity of 3.9pb-1 in e+ p reactions recorded with the ZEUS detector at HERA. Information from a silicon-strip tracking detector, installed in front of the small electromagnetic calorimeter used to measure the energy of the final-state positron at small scattering angles, together with an enhanced simulation of the hadronic final state, has permitted the extension of the kinematic range beyond that of previous measurements. The uncertainties in F2 are typically less than 4%. At the low Q2 values of the present measurement, the rise of F2 at low x is slower than observed in HERA data at higher Q2 and can be described by Regge theory with a constant logarithmic slope δlnF2/δln(1/x). The dependence of F2 on Q2 is stronger than at higher Q2 values, approaching, at the lowest Q2 values of this measurement, a region where F2 becomes nearly proportional to Q2. (C) 2000 Elsevier Science B.V.

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Sio2-Passivated Lateral-Geometry Gan Transparent Schottky-Barrier Detectors, V. Adivarahan, Grigory Simin, J. W. Yang, A. Lunev, M. Asif Khan, M. Pala, M. Shur, R. Gaska Aug 2000

Sio2-Passivated Lateral-Geometry Gan Transparent Schottky-Barrier Detectors, V. Adivarahan, Grigory Simin, J. W. Yang, A. Lunev, M. Asif Khan, M. Pala, M. Shur, R. Gaska

Faculty Publications

We report on a transparent Schottky-barrierultraviolet detector on GaN layers over sapphire substrates. Using SiO2 surface passivation, reverse leakage currents were reduced to a value as low as 1 pA at 5 V reverse bias for 200 μm diameter device. The device exhibits a high internal gain, about 50, at low forward biases. The response time (about 15 ns) is RC limited, even in the internal gain regime. A record low level of the noise spectral density, 5×10−23 A2/Hz, was measured at 10 Hz. We attribute this low noise level to the reduced reverse leakage current.

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An Approximation To Miscible Fluid Flows In Porous Media With Point Sources And Sinks By An Eulerian-Lagrangian Localized Adjoint Method And Mixed Finite Element Methods, Hong Wang, Liang Dong, Richard E. Ewing, Stephen L. Lyons, Guan Qin Aug 2000

An Approximation To Miscible Fluid Flows In Porous Media With Point Sources And Sinks By An Eulerian-Lagrangian Localized Adjoint Method And Mixed Finite Element Methods, Hong Wang, Liang Dong, Richard E. Ewing, Stephen L. Lyons, Guan Qin

Faculty Publications

We develop an Eulerian–Lagrangian localized adjoint method (ELLAM)-mixed finite element method (MFEM) solution technique for accurate numerical simulation of coupled systems of partial differential equations (PDEs), which describe complex fluid flow processes in porous media. An ELLAM, which was shown previously to outperform many widely used methods in the context of linear convection-diffusion PDEs, is presented to solve the transport equation for concentration. Since accurate fluid velocities are crucial in numerical simulations, an MFEM is used to solve the pressure equation for the pressure and Darcy velocity. This minimizes the numerical difficulties occurring in standard methods for approximating velocities caused …

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Preservation And Interpretive Plan For The Dill Tract Civil War Earthworks On James Island, South Carolina, Steven D. Smith Aug 2000

Preservation And Interpretive Plan For The Dill Tract Civil War Earthworks On James Island, South Carolina, Steven D. Smith

Faculty Publications

Beginning in the late fall of 1862 the Confederate Army defending Charleston began work on a line of earthworks and batteries across James Island, South Carolina, from Secessionville to the Stono River. The lines were called the "New Lines" to distinguish them from other lines built in 1861. Today, approximately 3,000 feet of these lines still exist in very good condition on a 17.3 acre tract of land that represent a portion of the Dill Tract. The tract and earthworks (archaeological site 38CH 195) are part of a noncontiguous district listed on the National Register of Historic Places and are …

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Mutational Analysis Of The Tra Locus Of The Broad-Host-Range Streptomyces Plasmid Pij101, Gregg S. Pettis, Stanley N. Cohen Aug 2000

Mutational Analysis Of The Tra Locus Of The Broad-Host-Range Streptomyces Plasmid Pij101, Gregg S. Pettis, Stanley N. Cohen

Faculty Publications

The tra gene of Streptomyces lividans plasmid pIJ101 encodes a 621- amino-acid protein that can mediate both plasmid transfer and the interbacterial transfer of chromosomal genes (i.e., chromosome-mobilizing ability [Cma]) during mating. Here we report the results of in-frame insertional mutagenesis studies aimed at defining regions of Tra required for these functions. While hexameric linker insertions throughout the tra gene affected plasmid and chromosomal gene transfer, insertions in a 200-amino- acid region of the Tra protein that contains presumed nucleotide-binding motifs and that is widely conserved among a functionally diverse family of bacterial and plasmid proteins (K. J. Begg, S. …

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Fuel Saving Strategies For Separated Spacecraft Interferometry, Timothy Mclain, Randal W. Beard, Christopher A. Bailey Aug 2000

Fuel Saving Strategies For Separated Spacecraft Interferometry, Timothy Mclain, Randal W. Beard, Christopher A. Bailey

Faculty Publications

Separated spacecraft interferometry missions will require spacecraft to move in a coordinated fashion to ensure minimal and balanced consumption of fuel. This paper develops strategies for determining interferometry mission plans that result in significant fuel savings over standard approaches. Simulation results demonstrate that valuable reductions in fuel consumption can be realized by combining the retargeting and imaging maneuvers required to image multiple stellar sources. Fuel-optimal imaging strategies have been developed for two-spacecraft interferometry missions similar to the proposed Space Technology 3 mission using chained local optimization methods. Based on these strategies, sampling pattern guidelines for space-borne interferometry missions have been …

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The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon Aug 2000

The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon

Faculty Publications

A high resolution, regional, non-linear, barotropic ocean model (2D POM) was used to show that a pressure difference between the Pacific and Indian Ocean does not significantly influence the total transport of the Indonesian throughflow.

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Trajectory Planning For Coordinated Rendezvous Of Unmanned Air Vehicles, Timothy W. Mclain, Randal W. Beard Aug 2000

Trajectory Planning For Coordinated Rendezvous Of Unmanned Air Vehicles, Timothy W. Mclain, Randal W. Beard

Faculty Publications

A trajectory generation strategy that facilitates the coordination of multiple unmanned air vehicles is developed. Of particular interest is the planning of threat-avoiding trajectories that result in the simultaneous arrival of multiple UAVs at their targets. In this approach, paths to the target are modeled using the physical analogy of a chain. A unique strength of the planning approach is the ability to specify or alter the path length by adding or subtracting links from the chain. Desirable paths to the target are obtained by simulating the dynamics of the chain where threats apply repulsive forces to the chain and …

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Electronic Billboards Along The Information Superhighway: Liability Under The Lanham Act For Using Trademarks To Key Internet Banner Ads, Christine Galbraith Davik Jul 2000

Electronic Billboards Along The Information Superhighway: Liability Under The Lanham Act For Using Trademarks To Key Internet Banner Ads, Christine Galbraith Davik

Faculty Publications

With almost one billion web pages on the Internet today, a search engine is a necessity at times. But search engines are also for-profit ventures and the financial success of these sites hinges on advertising revenue. One of the ways in which these sites generate income is by selling “keywords” to advertisers. Although there has been only one judicial decision – Playboy Enterprises, Inc. v. Netscape Communications – involving banner ads keyed to trademarks, it will undoubtedly not be the last. This article argues that despite the invisible nature of this unauthorized trademark use, the common practice of keying a …

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Gamma-Ray Bursts Have Millisecond Variability, Katharine C. Walker, Bradley E. Schaefer, E. E. Fenimore Jul 2000

Gamma-Ray Bursts Have Millisecond Variability, Katharine C. Walker, Bradley E. Schaefer, E. E. Fenimore

Faculty Publications

We have performed searches for isolated flares and for steady flickering in the initial ∼ 1 s of gamma-ray burst light curves on the microsecond to millisecond timescales. Two bursts among our sample of 20 revealed four isolated flares with timescales from 256 to 2048 μs. A wavelet analysis for our sample showed low-level flickering for all bursts on timescales from 256 μs to 33 ms, with the majority of bursts containing rise times faster than 4 ms and 30% having rise times faster than 1 ms. These results show that millisecond variability is common in classical bursts and not …

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Azimuth Variation In Microwave Scatterometer And Radiometer Data Over Antarctica, David G. Long, Mark R. Drinkwater Jul 2000

Azimuth Variation In Microwave Scatterometer And Radiometer Data Over Antarctica, David G. Long, Mark R. Drinkwater

Faculty Publications

While designed for ocean observation, scatterometer and radiometer data have proven very useful in a variety of cryosphere studies. Over large regions of Antarctica, ice sheet and bedrock topography and the snow deposition, drift, and erosional environment combine to produce roughness on various scales. Roughness ranges from broad, basin-scale ice-sheet topography at 100 km wavelengths to large, spatially coherent dune fields at 10 km wavelength to erosional features on the meter scale known as sastrugi. These roughness scales influence the microwave backscattering and emission properties of the surface, combining to introduce azimuth-angle dependencies in the satellite observation data. In this …

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Roughening, Deroughening, And Nonuniversal Scaling Of The Interface Width In Electrophoretic Deposition Of Polymer Chains, Frank W. Bentrem, Ras B. Pandey, Fereydoon Family Jul 2000

Roughening, Deroughening, And Nonuniversal Scaling Of The Interface Width In Electrophoretic Deposition Of Polymer Chains, Frank W. Bentrem, Ras B. Pandey, Fereydoon Family

Faculty Publications

Growth and roughness of the interface of deposited polymer chains driven by a field onto an impenetrable adsorbing surface are studied by computer simulations in (2 + 1) dimensions. The evolution of the interface width W shows a crossover from short-time growth described by the exponent beta(1) to a long-time growth with exponent beta(2) (>beta(1)) Tne saturated width increases, i.e., the interface roughens, with the molecular weight L-c, but the roughness exponent alpha (from W-s similar to L-alpha) becomes negative in contrast to models for particle deposition; cr depends on the chain length-a nonuniversal scaling with the substrate length …

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Almost Block Diagonal Linear Systems: Sequential And Parallel Solution Techniques, And Applications, P. Amodio, J.R. Cash, G. Roussos, R.W. Wright, G. Fairweather, I. Gladwell, G.L. Kraut, M. Paprzycki Jul 2000

Almost Block Diagonal Linear Systems: Sequential And Parallel Solution Techniques, And Applications, P. Amodio, J.R. Cash, G. Roussos, R.W. Wright, G. Fairweather, I. Gladwell, G.L. Kraut, M. Paprzycki

Faculty Publications

Almost block diagonal (ABD) linear systems arise in a variety of contexts, specifically in numerical methods for two-point boundary value problems for ordinary differential equations and in related partial differential equation problems. The stable, efficient sequential solution of ABDs has received much attention over the last fifteen years and the parallel solution more recently. We survey the fields of application with emphasis on how ABDs and bordered ABDs (BABDs) arise. We outline most known direct solution techniques, both sequential and parallel, and discuss the comparative efficiency of the parallel methods. Finally, we examine parallel iterative methods for solving BABD systems. …

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An Iterative Approach To Multisensor Sea Ice Classification, David G. Long, Mark R. Drinkwater, Quinn P. Remund Jul 2000

An Iterative Approach To Multisensor Sea Ice Classification, David G. Long, Mark R. Drinkwater, Quinn P. Remund

Faculty Publications

Characterizing the variability in sea ice in the polar regions is fundamental to an understanding of global climate and the geophysical processes governing climate changes. Sea ice can be grouped into a number of general classes with different characteristics. Multisensor data from NSCAT, ERS-2, and SSM/I are reconstructed into enhanced resolution imagery for use in ice-type classification. The resulting twelve-dimensional data set is linearly transformed through principal component analysis to reduce data dimensionality and noise levels. An iterative statistical data segmentation algorithm is developed using maximum likelihood (ML) and maximum a posteriori (MAP) techniques. For a given ice type, the …

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Diversity Performance Of Dual-Antenna Handsets Near Operator Tissue, Michael A. Jensen, Bruce M. Green Jul 2000

Diversity Performance Of Dual-Antenna Handsets Near Operator Tissue, Michael A. Jensen, Bruce M. Green

Faculty Publications

This paper presents a computational and experimental study of the diversity performance of two dual-antenna handsets operating indoors in the 902-928 MHz industrial, scientific, and medical (ISM) band. Of particular interest is the effect of the operator tissue on the diversity operation. Key indicators of diversity gain such as branch mean effective gain (MEG) and envelope correlation coefficient are obtained from finite-difference time-domain (FDTD) method simulations as well as from experimental measurements in three different indoor environments. Diversity gain for the handsets is also measured directly. Reasonable agreement is observed between the experimental and simulated results, with both approaches indicating …

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Neural Networks Versus Nonparametric Neighbor-Based Classifiers For Semisupervised Classification Of Landsat Thematic Mapper Imagery, Perry J. Hardin Jul 2000

Neural Networks Versus Nonparametric Neighbor-Based Classifiers For Semisupervised Classification Of Landsat Thematic Mapper Imagery, Perry J. Hardin

Faculty Publications

Semisupervised classification is one approach to converting multiband optical and infrared imagery into landcover maps. First, a sample of image pixels is extracted and clustered into several classes. The analyst next combines the clusters by hand to create a smaller set of groups that correspond to a useful landcover classification. The remaining image pixels are then assigned to one of the aggregated cluster groups by use of a per-pixel classifier. Since the cluster aggregation process frequently creates groups with multivariate shapes ill suited for parametric classifiers, there has been renewed interest in nonparametric methods for the task. This research reports …

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Labor Markets, Rationality, And Workers With Disabilities, Michael Ashley Stein Jul 2000

Labor Markets, Rationality, And Workers With Disabilities, Michael Ashley Stein

Faculty Publications

No abstract provided.

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Farewell To The Quick Look: Redefining The Scope And Content Of The Rule Of Reason, Alan J. Meese Jul 2000

Farewell To The Quick Look: Redefining The Scope And Content Of The Rule Of Reason, Alan J. Meese

Faculty Publications

No abstract provided.

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On Casebooks And Canons Or Why Bob Jones University Will Never Be Part Of The Constitutional Law Canon, Neal Devins Jul 2000

On Casebooks And Canons Or Why Bob Jones University Will Never Be Part Of The Constitutional Law Canon, Neal Devins

Faculty Publications

No abstract provided.

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Gan-Algan Heterostructure Field-Effect Transistors Over Bulk Gan Substrates, M. Asif Khan, J. W. Yang, W. Knap, E. Frayssinet, X. Hu, Grigory Simin, P. Prystawko, M. Leszczynski, I. Grzegory, S. Porowski, R. Gaska, M. S. Shur, B. Beaumont, M. Teisseire, G. Neu Jun 2000

Gan-Algan Heterostructure Field-Effect Transistors Over Bulk Gan Substrates, M. Asif Khan, J. W. Yang, W. Knap, E. Frayssinet, X. Hu, Grigory Simin, P. Prystawko, M. Leszczynski, I. Grzegory, S. Porowski, R. Gaska, M. S. Shur, B. Beaumont, M. Teisseire, G. Neu

Faculty Publications

We report on AlGaN/GaN heterostructures and heterostructurefield-effect transistors(HFETs) fabricated on high-pressure-grown bulk GaN substrates. The 2delectron gas channel exhibits excellent electronic properties with room-temperature electron Hall mobility as high as μ=1650 cm2/V s combined with a very large electron sheet density ns≈1.4×1013 cm−2.The HFET devices demonstrated better linearity of transconductance and low gate leakage, especially at elevated temperatures. We also present the comparative study of high-current AlGaN/GaN HFETs(nsμ>2×1016 V−1 s−1) grown on bulk GaN, sapphire, and SiC substrates under the same conditions. We demonstrate that in …

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Effectiveness Of A Multimedia General Education Course, Patricia Backer Jun 2000

Effectiveness Of A Multimedia General Education Course, Patricia Backer

Faculty Publications

The current paper describes the design, development, and evaluation of self-paced multimedia modules that are used in an advanced General Education course at San Jose State University. The design and development cycle of these modules began in 1994 and continues to this date. The General Education course, Technology and Civilization (TECH 198), is designed to introduce students to the realm of history and usage of technology in society and to increase their awareness of both the uncertainties as well as the promises of the utilization of technology as a creative human enterprise. During the summer session 1999, the completed modules …

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Electronic Structure Of Bas And Boride Iii-V Alloys, Gus L. W. Hart, Alex Zunger Jun 2000

Electronic Structure Of Bas And Boride Iii-V Alloys, Gus L. W. Hart, Alex Zunger

Faculty Publications

Boron arsenide, the typically ignored member of the Group-III–V arsenide series BAs-AlAs-GaAs-InAs is found to resemble silicon electronically: its Γ conduction-band minimum is p-like (Γ15), not s-like (Γ1c), it has an X1c-like indirect band gap, and its bond charge is distributed almost equally on the two atoms in the unit cell, exhibiting nearly perfect covalency. The reasons for these are tracked down to the anomalously low atomic p orbital energy in the boron and to the unusually strong s–s repulsion in BAs relative to most other Group-III–V compounds. We find unexpected valence-band offsets of BAs with respect to GaAs and …

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Fast Algorithm For Generating Sorted Contour Strings, Norman L. Jones, Michael J. Kennard, Alan K. Zundel Jun 2000

Fast Algorithm For Generating Sorted Contour Strings, Norman L. Jones, Michael J. Kennard, Alan K. Zundel

Faculty Publications

Automatic generation of contours for graphical display and map plotting has been studied extensively since the early days of computing. The individual segments making up a contour line are often determined by subdividing the object of interest into small triangles and computing the contours assuming a linear variation on each triangle. However, efficient storage of contour data and the need to place labels (automatically) or to smooth the contours require that the contours be generated in continuous strings of segments. A simple approach to generate such strings is to sort the randomly generated contour segments. Since sorting can be time-consuming, …

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Comparison Of Charged Sheets And Corrected 3-D Ewald Calculations Of Long-Range Forces In Slab Geometry Electrolyte Systems With Solvent Molecules, Richard L. Rowley, Paul S. Crozier, Eckhard Spoht, Douglas Henderson Jun 2000

Comparison Of Charged Sheets And Corrected 3-D Ewald Calculations Of Long-Range Forces In Slab Geometry Electrolyte Systems With Solvent Molecules, Richard L. Rowley, Paul S. Crozier, Eckhard Spoht, Douglas Henderson

Faculty Publications

Two methods of calculating long-range intermolecular potentials are compared for an approximately 3 M aqueous electrolyte solution confined between two charged surfaces. We investigate the ionic density profiles using the charged-sheets method and the corrected three-dimensional (3D) Ewald method at two different system sizes and also compare the Coulomb forces directly. The corrected 3D Ewald method is recommended for the calculation of long-range potentials in systems of this nature because it is less system size dependent than the charged sheets method and the resultant forces are more consistent with periodic boundaries. However, the charged-sheets method for estimating long-range potentials in …

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Statistical Continuum Theory For Large Plastic Deformation Of Polycrystalline Materials, Brent L. Adams, S. Ahzi, H. Garmestani, S. Lin Jun 2000

Statistical Continuum Theory For Large Plastic Deformation Of Polycrystalline Materials, Brent L. Adams, S. Ahzi, H. Garmestani, S. Lin

Faculty Publications

This paper focuses on the application of statistical continuum mechanics to the prediction of mechanical response of polycrystalline materials and microstructure evolution under large plastic deformations. A statistical continuum mechanics formulation is developed by applying a Green's function solution to the equations of stress equilibrium in an infinite domain. The distribution and morphology of grains (crystals) in polycrystalline materials is represented by a set of correlation functions that are described by the corresponding probability functions. The elastic deformation is neglected and a viscoplastic power law is employed for crystallographic slip in single crystals. In this formulation, two- and three-point probability …

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X-Ray Rocking Curve Analysis Of Tetragonally Distorted Ternary Semiconductors On Mismatched (001) Substrates, X. Zhang, David W. Parent, P. Li, A. Rodriguez, G. Zhao, J. Ayers, F. Jain Jun 2000

X-Ray Rocking Curve Analysis Of Tetragonally Distorted Ternary Semiconductors On Mismatched (001) Substrates, X. Zhang, David W. Parent, P. Li, A. Rodriguez, G. Zhao, J. Ayers, F. Jain

Faculty Publications

For ternary heteroepitaxial layers, the independent determination of the composition and state of strain requires x-ray rocking curve measurements for at least two different hkl reflections because the relaxed lattice constant is a function of the composition. The usual approach involves the use of one symmetric reflection and one asymmetric reflection. Two rocking curves are measured at opposing azimuths for each hkl reflection. Thus, it is possible to account for tilting of the hkl planes in the epitaxial layer with respect to the hkl planes in the substrate, by averaging the peak separations obtained at the opposing azimuths. This procedure …

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Digital Image Managers: A Unique Partnership, Samantha K. Hastings Jun 2000

Digital Image Managers: A Unique Partnership, Samantha K. Hastings

Faculty Publications

The University of North Texas and the African American Museum in Dallas are partners in a program designed to produce expert managers of digital images and information. The School of Library and Information Sciences in cooperation with the School of Visual Arts received a 1998 National Leadership Grant from the U.S. Institute of Museum and Library Services to build a collaborative program that includes a digital imaging laboratory and fellowships for students in a Certificate of Advanced Study Program. The work of the digital image manager includes the production of visual images, the creation and management of databases, and the …

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Global System Of Rivers: Its Role In Organizing Continental Land Mass And Defining Land‐To‐Ocean Linkages, Charles J. Vorosmarty, Balazs M. Fekete, M. Meybeck, Richard B. Lammers Jun 2000

Global System Of Rivers: Its Role In Organizing Continental Land Mass And Defining Land‐To‐Ocean Linkages, Charles J. Vorosmarty, Balazs M. Fekete, M. Meybeck, Richard B. Lammers

Faculty Publications

The spatial organization of the Earth's land mass is analyzed using a simulated topological network (STN‐30p) representing potential flow pathways across the entire nonglacierized surface of the globe at 30‐min (longitude × latitude) spatial resolution. We discuss a semiautomated procedure to develop this topology combining digital elevation models and manual network editing. STN‐30p was verified against several independent sources including map products and drainage basin statistics, although we found substantial inconsistency within the extant literature itself. A broad suite of diagnostics is offered that quantitatively describes individual grid cells, river segments, and complete drainage systems spanning orders 1 through 6 …

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Measurement Of Inclusive(D(S)(±)) Photoproduction At Hera Zeus Collaboration, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti May 2000

Measurement Of Inclusive(D(S)(±)) Photoproduction At Hera Zeus Collaboration, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

The first measurement of inclusive D(s)(±) photoproduction at HERA has been performed with the ZEUS detector for photon-proton centre-of-mass energies 130 < W < 280GeV. The measured cross section for 3 < p (is perpendicular to)/(D(s)) < 12GeV and |η(D(s))| < 1.5 is σ(ep → D(s)X) = 3.79 ± 0.59(stat.) -0.46/+0.26 (syst.) ± 0.94(br.)nb, where the last error arises from the uncertainty in the D(s)(±) decay branching ratio. The measurements are compared with inclusive D*(±) photoproduction cross sections in the same kinematic region and with QCD calculations. The D(s)(±) cross sections lie above a fixed-order next-to-leading order calculation and agree better with a tree-level O(αα(s)/3) calculation that was tuned to describe the ZEUS D*(±) cross sections. The ratio of D(s)(±) to D*(±) cross sections is 0.41 ± 0.07 (stat.) -0.05/+0.03 (syst.) ± 0.10(br.). From this ratio, the strangeness-suppression factor in charm photoproduction, within the LUND string fragmentation model, has been calculated to be γ(s) = 0.27 ± 0.05 ± 0.07(br.). The cross-section ratio and γ(s) are in good agreement with those obtained in charm production in e+e- annihilation. (C) 2000 Elsevier Science B.V.

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