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A General Model Of Resistive Wall Instability In Linear Accelerators, Jean R. Delayen Jan 2007

A General Model Of Resistive Wall Instability In Linear Accelerators, Jean R. Delayen

Physics Faculty Publications

A general model for wakefield-generated instabilities in linear accelerators, originally developed for cumulative beam breakup [1], is applied to the resistive wall instability. The general solution for various bunch charge distributions and application to various accelerator configurations are presented.

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Reactive Oxygen Emission From Microwave Discharge Plasmas, S. Popovic, M. Rašković, S. P. Kuo, L. Vuskovic Jan 2007

Reactive Oxygen Emission From Microwave Discharge Plasmas, S. Popovic, M. Rašković, S. P. Kuo, L. Vuskovic

Physics Faculty Publications

Metastable oxygen atoms and molecules have received increased interest because of their function in surface modification, bio-decontamination and many other industrial applications, in addition to the role in the upper atmospheric layer chemistry. We review work on production and detection of metastable oxygen and we describe our experiments, including the development of techniques for measurement of metastable molecular oxygen. We show that either metastable oxygen molecules or metastable oxygen atoms can be produced in large quantities in electrical discharges, carefully tailored to promote the required kinetics. Although the two species may coexist, colder discharge regimes favor production of molecules, while …

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Quark-Hadron Duality In Spin Structure Functions G(1)(P) And G(1)(D), P. E. Bosted, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, S. E. Kuhn, Y. Prok, G. Adams, M. Amarian, P. Ambrozewicz, M. Anghinolfi, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang Jan 2007

Quark-Hadron Duality In Spin Structure Functions G(1)(P) And G(1)(D), P. E. Bosted, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, S. E. Kuhn, Y. Prok, G. Adams, M. Amarian, P. Ambrozewicz, M. Anghinolfi, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang

Physics Faculty Publications

New measurements of the spin structure functions of the proton and deuteron g(1)(p)(x,Q2) and g(1)(d)(x,Q2) in the nucleon resonance region are compared with extrapolations of target-mass-corrected next-to-leading-order (NLO) QCD fits to higher energy data. Averaged over the entire resonance region (W <2 >GeV), the data and QCD fits are in good agreement in both magnitude and Q2 dependence for Q2 >1.7 GeV2/c2. This "global" duality appears to result from cancellations among the prominent "local" resonance regions: in particular strong σ …

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Form Factors And Wave Functions Of Vector Mesons In Holographic Qcd, Hovhannes R. Grigoryan, Anatoly V. Radyushkin Jan 2007

Form Factors And Wave Functions Of Vector Mesons In Holographic Qcd, Hovhannes R. Grigoryan, Anatoly V. Radyushkin

Physics Faculty Publications

Within the framework of a holographic dual model of QCD, we develop a formalism for calculating form factors of vector mesons. We show that the holographic bound states can be described not only in terms of eigenfunctions of the equation of motion, but also in terms of conjugate wave functions that are close analogues of quantum-mechanical bound state wave functions. We derive a generalized VMD representation for form factors, and find a very specific VMD pattern, in which form factors are essentially given by contributions due to the first two bound states in the Q2 -channel. We calculate electric …

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Plasma Treatment Of Bulk Nb Surface In The Ar/Cl2 Discharge, M. Rašković, L. Vuskovic, S. Popovic, A.-M. Valente-Feliciano, L. Phillips Jan 2007

Plasma Treatment Of Bulk Nb Surface In The Ar/Cl2 Discharge, M. Rašković, L. Vuskovic, S. Popovic, A.-M. Valente-Feliciano, L. Phillips

Physics Faculty Publications

The preparation of the cavity walls has been one of the major challenges in the superconducting radio-frequency (SRF) accelerator technology. Therefore, constant research and development effort is devoted to develop surface preparation processes that will improve roughness and lower the level of impurities, like hydrogen or oxygen, embedded in bulk Nb, having in the same time reasonable etching rates. Plasma based surface modification provides an excellent opportunity to achieve these goals. We present Ar/Cl2 discharge treatment of bulk Nb where we achieved etching rates comparable to the rates obtained with the electropolishing method without introducing impurities in Nb. The …

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Cascade Production In The Reactions 𝛾p → K⁺ K⁺(X) And 𝛾p → K⁺K⁺ Π⁻⁻(X), M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration Jan 2007

Cascade Production In The Reactions 𝛾p → K⁺ K⁺(X) And 𝛾p → K⁺K⁺ Π⁻⁻(X), M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

Photoproduction of the cascade resonances has been investigated in the reactions γp → K + K +(X) and γp → K + K + π −(X). The mass splitting of the ground state (Ξ−,Ξ0) doublet is measured to be 5.4 ± 1.8 MeV/c2, consistent with existing measurements. The differential (total) cross sections for the Ξ− have been determined for photon beam energies from 2.75 to 3.85 (4.75) GeV and are consistent with a production mechanism of Y∗→K+Ξ− through a t-channel process. The reaction γp→K+K+π−[Ξ0] has also been investigated to …

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Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev, M. Amarian, H. Bagdasaryan, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration Jan 2007

Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev, M. Amarian, H. Bagdasaryan, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

Differential cross sections for the reaction 𝛾p→ K*0Σ+ are presented in the photon energy range of 1.7 to 3.0 GeV. The K*0 was detected by its decay products, K+π−, in the Continuous Electron Beam Accelerator Facility's large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility. These data are the first K*0 photoproduction cross sections ever published over a broad range of angles. Comparison with a theoretical model based on the vector and tensor K∗-quark couplings shows good agreement with the data, except at forward angles, suggesting that …

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Erratum: Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev (Physical Review C. 75, 042201), M. Amarian, H. Bagdasaryan, S. Bültmann, G. E. Dodge, G. Gavalian, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, F. Sabatié, L. B. Weinstein, Et. Al., The Clas Collaboration Jan 2007

Erratum: Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev (Physical Review C. 75, 042201), M. Amarian, H. Bagdasaryan, S. Bültmann, G. E. Dodge, G. Gavalian, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, F. Sabatié, L. B. Weinstein, Et. Al., The Clas Collaboration

Physics Faculty Publications

No abstract provided.

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First Measurement Of Beam-Recoil Observables CX And CZ In Hyperon Photoproduction, M. J. Amaryan, H. Bagdasaryan, H. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration Jan 2007

First Measurement Of Beam-Recoil Observables CX And CZ In Hyperon Photoproduction, M. J. Amaryan, H. Bagdasaryan, H. Bektasoglu, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions →γ + p → K+ + →Λ and →γ+p → K+ + →Σ0. The data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS) detector at the Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos θc.m.K+ < +0.95. For the Λ, the polarization transfer coefficient along the photon momentum axis, Cz, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient Cx is smaller than Cz by a roughly …

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Experimental Study Of Exclusive ²H(E,E'P)N Reaction Mechanisms At High Q², S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, M. R. Niroula, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, J. Zhang, Et. Al., Clas Collaboration Jan 2007

Experimental Study Of Exclusive ²H(E,E'P)N Reaction Mechanisms At High Q², S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, M. R. Niroula, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, J. Zhang, Et. Al., Clas Collaboration

Physics Faculty Publications

The reaction 2H(e,e(')p)n has been studied with full kinematic coverage for photon virtuality 1.75 < Q2< 5.5 GeV2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (pn< 100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100 < pn< 750 MeV/c, proton-neutron rescattering dominates the cross section, while Delta production followed by the NΔ → NN transition is the primary contribution at higher momenta.

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Measurement Of Coherent ɸ-Meson Photoproduction From The Deuteron At Low Energies, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et. Al., Clas Collaboration Jan 2007

Measurement Of Coherent ɸ-Meson Photoproduction From The Deuteron At Low Energies, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et. Al., Clas Collaboration

Physics Faculty Publications

The cross section and decay angular distributions for the coherent ɸ-meson photoproduction on the deuteron have been measured for the first time up to a squared four-momentum transfer t = (pᵧ - pɸ)2 =-2 GeV2/c2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are compared with predictions from a rescattering model. In a framework of vector meson dominance, the data are consistent with the total ɸ-N cross section σɸN at about 10 mb. If vector meson dominance is violated, a larger σɸN is possible by introducing a …

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Crate: A Simple Model For Self-Describing Web Resources, Joan A. Smith, Michael L. Nelson Jan 2007

Crate: A Simple Model For Self-Describing Web Resources, Joan A. Smith, Michael L. Nelson

Computer Science Faculty Publications

If not for the Internet Archive’s efforts to store periodic snapshots of the web, many sites would not have any preservation prospects at all. The barrier to entry is too high for everyday web sites, which may have skilled webmasters managing them, but which lack skilled archivists to preserve them. Digital preservation is not easy. One problem is the complexity of preservation models, which have specific meta-data and structural requirements. Another problem is the time and effort it takes to properly prepare digital resources for preservation in the chosen model. In this paper, we propose a simple preservation model called …

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How Much Preservation Do I Get If I Do Absolutely Nothing? Using The Web Infrastructure For Digital Preservation, Martin Klein, Frank Mccown, Joan A. Smith, Michael Nelson Jan 2007

How Much Preservation Do I Get If I Do Absolutely Nothing? Using The Web Infrastructure For Digital Preservation, Martin Klein, Frank Mccown, Joan A. Smith, Michael Nelson

Computer Science Faculty Publications

To date, most of the focus regarding digital preservation has been on removing copies of the resources to be preserved from the “living web” and placing them in an archive for controlled curation. Once inside an archive, the resources are subject to careful processes of refreshing (making additional copies to new media) and migrating (conversion to new formats and applications). For small numbers of resources of known value, this is a practical and worthwhile approach to digital preservation. However, due to the infrastructure costs (storage, networks, machines) and more importantly the human management costs, this approach is unsuitable for web …

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Brass: A Queueing Manager For Warrick, Frank Mccown, Amine Benjelloun, Michael L. Nelson Jan 2007

Brass: A Queueing Manager For Warrick, Frank Mccown, Amine Benjelloun, Michael L. Nelson

Computer Science Faculty Publications

When an individual loses their website and a backup can-not be found, they can download and run Warrick, a web-repository crawler which will recover their lost website by crawling the holdings of the Internet Archive and several search engine caches. Running Warrick locally requires some technical know-how, so we have created an on-line queueing system called Brass which simplifies the task of recovering lost websites. We discuss the technical aspects of recon-structing websites and the implementation of Brass. Our newly developed system allows anyone to recover a lost web-site with a few mouse clicks and allows us to track which …

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Optimal Layout Of Multicast Groups Using Network Embedded Multicast Security In Ad Hoc Sensor Networks, Richard R. Brooks, Brijesh Pillai, Michele C. Weigle, Matthew Pirretti Jan 2007

Optimal Layout Of Multicast Groups Using Network Embedded Multicast Security In Ad Hoc Sensor Networks, Richard R. Brooks, Brijesh Pillai, Michele C. Weigle, Matthew Pirretti

Computer Science Faculty Publications

This paper considers the security of sensor network applications. Our approach creates multicast regions that use symmetric key cryptography for communications. Each multicast region contains a single keyserver that is used to perform key management and maintain the integrity of a multicast region. Communications between two multicast regions is performed by nodes that belong to both regions. To ease the network management burden, it is desirable for the networks to self-organize into regions and dynamically select their keyservers. This paper shows how to determine the number of keyservers (k) to use and the size in the number of hops (h) …

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Hybrid Training With Binary Search Protocol For Wireless Sensor Networks, Ruzana Ishak, Qingwen Xu, Stephan Olariu, Shaharuddin Salleh Jan 2007

Hybrid Training With Binary Search Protocol For Wireless Sensor Networks, Ruzana Ishak, Qingwen Xu, Stephan Olariu, Shaharuddin Salleh

Computer Science Faculty Publications

Locationing problem in Wireless Sensor Networks(WSN) can be viewed as a general distributed sensor problem. It is with sensors that can discover other nodes or estimate ranges between nodes. that serve as position references. In this paper. we show that sensors acquire coarse-grain location awareness by the training protocol. The training protocol which hybrids the synchronization and training procedure. In this protocol, synchronization and training are combined into one scheme. The sink node sends two beacons in each slot instead of one. In the training, sensor searching for its location using a binary search scheme. Our simulation results shown less …

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All Minimal Prime Extensions Of Hereditary Classes Of Graphs, Vassilis Giakoumakis, Stephan Olariu Jan 2007

All Minimal Prime Extensions Of Hereditary Classes Of Graphs, Vassilis Giakoumakis, Stephan Olariu

Computer Science Faculty Publications

The substitution composition of two disjoint graphs G1 and G2 is obtained by first removing a vertex x from G2 and then making every vertex in G1 adjacent to all neighbours of x in G2. Let F be a family of graphs defined by a set Z* of forbidden configurations. Giakoumakis [V. Giakoumakis, On the closure of graphs under substitution, Discrete Mathematics 177 (1997) 83–97] proved that F∗, the closure under substitution of F, can be characterized by a set Z∗ of forbidden configurations — the minimal prime extensions of Z. He also …

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The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher Jan 2007

The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular-level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low-resolution (> 3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (> 200000) techniques such as electrospray ionization (ESI) coupled …

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Simulation Of The Recent Multidecadal Increase Of Atlantic Hurricane Activity Using An 18-Km-Grid Regional Model, Thomas R. Knutson, Joseph J. Sirutis, Stephen T. Garner, Isaac M. Held, Robert E. Tuleya Jan 2007

Simulation Of The Recent Multidecadal Increase Of Atlantic Hurricane Activity Using An 18-Km-Grid Regional Model, Thomas R. Knutson, Joseph J. Sirutis, Stephen T. Garner, Isaac M. Held, Robert E. Tuleya

CCPO Publications

In this study, a new modeling framework for simulating Atlantic hurricane activity is introduced. The model is an 18-km-grid nonhydrostatic regional model, run over observed specified SSTs and nudged toward observed time-varying large-scale atmospheric conditions (Atlantic domain wavenumbers 0-2) derived from the National Centers for Environmental Prediction (NCEP) reanalyses. Using this "perfect large-scale model" approach for 27 recent August-October seasons (1980-2006), it is found that the model successfully reproduces the observed multidecadal increase in numbers of Atlantic hurricanes and several other tropical cyclone (TC) indices over this period. The correlation of simulated versus observed hurricane activity by year varies from …

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Using Concentration Index To Study Changes In Socio-Economic Inequality Of Overweight Among Us Adolescents Between 1971 And 2002, Qi Zhang, Youfa Wang Jan 2007

Using Concentration Index To Study Changes In Socio-Economic Inequality Of Overweight Among Us Adolescents Between 1971 And 2002, Qi Zhang, Youfa Wang

Community & Environmental Health Faculty Publications

Background: The prevalence of overweight among adolescents continues to increase in the United States. This study examines the changes in socio-economic status (SES) inequality of overweight among US adolescents in the past three decades.

Methods: Concentration Index (CI) was utilized to measure changes in the SES inequality in prevalence of overweight among US adolescents. Data collected from 15286 adolescents in four waves of the National Health and Nutrition Examination Surveys (NHANES) between 1971 and 2002 and Hispanic Health and Nutrition Examination Survey (HHANES) (1982-84) were used.

Results: Changes in the SES inequality of overweight among US adolescents and considerable gender …

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The Shape Of Pulverized Bituminous Vitrinite Coal Particles, Jonathan P. Mathews, Patrick G. Hatcher, Alan W. Scaroni Jan 2007

The Shape Of Pulverized Bituminous Vitrinite Coal Particles, Jonathan P. Mathews, Patrick G. Hatcher, Alan W. Scaroni

Chemistry & Biochemistry Faculty Publications

The shape of pulverized bituminous coal particles (vitrinites) was determined by optical and laser light scattering. Vitrain samples were collected from obvious tree remains located in the ceilings of two Appalachian coal mines. Wet sieving produced narrow size cuts. The particles were determined to be oblong or blocky in shape, with average length-to-width ratio of 1.7 and sphericity of 0.78. They were analogous in shape to a square ended, rectangular "house brick". The two bituminous coals and different size cuts of each coal had essentially the same shape parameters. Characteristic heating times and terminal velocities were higher by 22 and …

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Comparison Of Perceptions Of Inclusion Between University Instructors And Students With Disabilities In Ukraine, Sharon A. Raver, Kateryna Kolchenko Jan 2007

Comparison Of Perceptions Of Inclusion Between University Instructors And Students With Disabilities In Ukraine, Sharon A. Raver, Kateryna Kolchenko

Communication Disorders & Special Education Faculty Publications

Ukraine is currently involved in a heated debate about inclusion at all levels of education. This debate has become part of the country's efforts to improve human rights. Prior to independence in 1991, students with disabilities in Ukraine who desired higher education were not permitted to attend universities. How instructors and students with disabilities perceive the process of integration is important for Ukraine's continued movement toward becoming an egalitarian society. This study examined the differences in attitude regarding inclusion and university life between university instructors and students with special needs attending Open International University of Human Development “UKRAINE,” the only …

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Bioelectric Effects Of Intense Nanosecond Pulses, Karl H. Schoenbach, Barbara Y. Hargrave, Ravindra P. Joshi, Juergen F. Kolb, Richard Nuccitelli, Christopher J. Osgood, Andrei G. Pakhomov, Michael W. Stacey, James R. Swanson, Jody A. White, Shu Xiao, Jue Zhang, Stephen J. Beebe, Peter F. Blackmore, E. Stephen Buescher Jan 2007

Bioelectric Effects Of Intense Nanosecond Pulses, Karl H. Schoenbach, Barbara Y. Hargrave, Ravindra P. Joshi, Juergen F. Kolb, Richard Nuccitelli, Christopher J. Osgood, Andrei G. Pakhomov, Michael W. Stacey, James R. Swanson, Jody A. White, Shu Xiao, Jue Zhang, Stephen J. Beebe, Peter F. Blackmore, E. Stephen Buescher

Bioelectrics Publications

Electrical models for biological cells predict that reducing the duration of applied electrical pulses to values below the charging time of the outer cell membrane (which is on the order of 100 ns for mammalian cells) causes a strong increase in the probability of electric field interactions with intracellular structures due to displacement currents. For electric field amplitudes exceeding MV/m, such pulses are also expected to allow access to the cell interior through conduction currents flowing through the permeabilized plasma membrane. In both cases, limiting the duration of the electrical pulses to nanoseconds ensures only nonthermal interactions of the electric …

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Lipschitz Continuity And Gateaux Differentiability Of The Best Approximation Operator In Vector-Valued Chebyshev Approximation, Martin Bartelt, John Swetits Jan 2007

Lipschitz Continuity And Gateaux Differentiability Of The Best Approximation Operator In Vector-Valued Chebyshev Approximation, Martin Bartelt, John Swetits

Mathematics & Statistics Faculty Publications

When G is a finite-dimensional Haar subspace of C ( X, Rk), the vector-valued functions (including complex-valued functions when k is 2) frorn a finite set X to Euclidean k-dimensional space, it is well-known that at any function f in C ( X, Rk) the best approximation operator satisfies the Strong Unicity condition of order 2 and a Lipschitz (Holder) condition of order 1/2. This note shows that in fact the best approximation operator satisfies the usual Lipschitz condition of order 1 and has a Gateaux derivative on a dense set of functions in C …

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Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig Jan 2007

Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) can result in verapamil-reversible CQ resistance and altered susceptibility to other antimalarials. PfCRT contains 10 membrane-spanning domains and is found in the digestive vacuole (DV) membrane of intraerythrocytic parasites. The mechanism by which PfCRT mediates CQ resistance is unclear although it is associated with decreased accumulation of drug within the DV. On the permissive background of the P. falciparum 106/1(K76) parasite line, we used single-step drug selection to generate isogenic clones containing unique pfcrt point mutations that resulted in amino acid changes in PfCRT transmembrane domains 1 (C72R, K76N, K76I …

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In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu Jan 2007

In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Real-time study of the transport and biocompatibility of nanomaterials in early embryonic development at single-nanoparticle resolution can offer new knowledge about the delivery and effects of nanomaterials in vivo, and provide new insights into molecular transport mechanisms in developing embryos. In this study, we directly characterized the transport of single silver nanoparticles into an in vivo model system (zebrafish embryos) and investigated their effects on early embryonic development at single-nanoparticle resolution in real time. We designed highly purified and stable (not aggregated and no photodecomposition) nanoparticles and developed single-nanoparticle optics and in vivo assays to enable the study. We …

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Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 2. Effects Of Physical And Biogeochemical Processes, Baris Salihoglu, Eileen E. Hofmann Jan 2007

Simulations Of Phytoplankton Species And Carbon Production In The Equatorial Pacific Ocean 2. Effects Of Physical And Biogeochemical Processes, Baris Salihoglu, Eileen E. Hofmann

CCPO Publications

A one-dimensional multi-component lower trophic level ecosystem model that includes detailed algal physiology is used to investigate the response of phytoplankton community and carbon production and export to variations in physical and biochemical processes in the Cold Tongue region of the equatorial Pacific Ocean at ON, 140W. Results show that high-frequency variability in vertical advection and temperature is an important mechanism driving the carbon export. Filtering out low frequency physical forcing results in a 30% increase in primary production and dominance of high-light adapted Prochlorococcus and autotrophic eukaryotes. Sensitivity studies show that iron availability is the primary control on carbon …

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Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2005, Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman Jan 2007

Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2005, Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

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Prediction Of Interference Pathloss Inside Commercial Aircraft Using Modulated Fuzzy Logic And Neural Networks, Madiha Jamil Jafri Jan 2007

Prediction Of Interference Pathloss Inside Commercial Aircraft Using Modulated Fuzzy Logic And Neural Networks, Madiha Jamil Jafri

Electrical & Computer Engineering Theses & Dissertations

Although several modeling techniques have been used to model indoor radio wave propagation and coupling patterns, to date no efficient model exists that calculates indoor-outdoor radio wave propagations on commercial aircraft. Due to the complexity of an aircraft structure, with the additive introduction of creeping wave phenomenon and unknown back-door propagation values from the exterior aircraft antenna to the avionics bay, numerical modeling approaches using Method of Moments (MoM) or Finite Difference Time Domain (FDTD) prove too complex with limitations. This dissertation presents an expert neuro-fuzzy (NF) model for Interference pathloss (IPL) predictions inside an Airbus 320 (A320) airplane, for …

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Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan Jan 2007

Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan

Biological Sciences Theses & Dissertations

The habitats at the VCR LTER that were the focus of the current study are the Hog Island and Parramore Island 'pimples', small, rounded dunes forming along main dune ridges of the barrier islands. There are distinct plant assemblage zones found on pimples, although most of these dunes are 10–20 m in diameter. Hypotheses of the study were that fresh water availability was a main determinant of differences between assemblages and that pimple size and location would influence diversity and assemblage structure. Research goals were (1) to describe the plant assemblages on pimples, (2) to relate edaphic and geomorphological factors …

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