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Articles 210751 - 210780 of 294135

Full-Text Articles in Physical Sciences and Mathematics

Reproducible Increased Mg Incorporation And Large Hole Concentration In Gan Using Metal Modulated Epitaxy, Shawn D. Burnham, Gon Namkoong, David C. Look, Bruce Clafin, W. Alan Doolittle Jan 2008

Reproducible Increased Mg Incorporation And Large Hole Concentration In Gan Using Metal Modulated Epitaxy, Shawn D. Burnham, Gon Namkoong, David C. Look, Bruce Clafin, W. Alan Doolittle

Electrical & Computer Engineering Faculty Publications

The metal modulated epitaxy (MME) growth technique is reported as a reliable approach to obtain reproducible large hole concentrations in Mg-doped GaN grown by plasma-assisted molecular-beam epitaxy on c-plane sapphire substrates. An extremely Ga-rich flux was used, and modulated with the Mg source according to the MME growth technique. The shutter modulation approach of the MME technique allows optimal Mg surface coverage to build between MME cycles and Mg to incorporate at efficient levels in GaN films. The maximum sustained concentration of Mg obtained in GaN films using the MME technique was above 7 × 1020 cm-3 …


Hypersonic Boundary Layer Receptivity To Acoustic Disturbances Over Cones, Kursat Kara Jan 2008

Hypersonic Boundary Layer Receptivity To Acoustic Disturbances Over Cones, Kursat Kara

Mechanical & Aerospace Engineering Theses & Dissertations

The receptivity mechanisms of hypersonic boundary layers to free stream acoustic disturbances are studied using both linear stability theory (LST) and direct numerical simulations (DNS). A computational code is developed for numerical simulation of steady and unsteady hypersonic flow over cones by combining a fifth-order weighted essentially non-oscillatory (WENO) scheme with third-order total-variation-diminishing (TVD) Runge-Kutta method. Hypersonic boundary layer receptivity to free-stream acoustic disturbances in slow and fast modes over 5-degree, half-angle blunt cones and wedges are numerically investigated. The free-stream Mach number is 6.0, and the unit Reynolds number is 7.8×106/ft. Both the steady and unsteady solutions are obtained …


Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi Jan 2008

Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi

Civil & Environmental Engineering Theses & Dissertations

Acoustic fatigue is one of the major design considerations for skin panels exposed to high levels of random pressure at subsonic/supersonic/hypersonic speeds. The nonlinear large deflection random response of the single-bay panels aerospace structures subjected to random excitations at various sound pressure levels (SPLs) is investigated. The nonlinear responses of plate analyses are limited to determine the root-mean-square displacement under uniformly distributed pressure random loads. Efficient computational technologies like sparse storage schemes and parallel computation are proposed and incorporated to solve large-scale, nonlinear large deflection random vibration problems for both types of loading cases: (1) synchronized in time and (2) …


Rapid Prototyping For Virtual Environments, Emre Baydogan Jan 2008

Rapid Prototyping For Virtual Environments, Emre Baydogan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Environment (VE) applications is challenging where application developers are required to have expertise in the target VE technologies along with the problem domain expertise. New VE technologies impose a significant learning curve to even the most experienced VE developer. The proposed solution relies on synthesis to automate the migration of a VE application to a new unfamiliar VE platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) is developed, that serves as a superset/model representation of the target virtual world. Input modules are developed to populate the framework with the capabilities of the virtual world …


Catalytic Wet Air Oxidation Of Mono Azo Dye Orange Ii: Catalyst Selection, Reaction Kinetics, And Modeling, Pinar Ozdural Jan 2008

Catalytic Wet Air Oxidation Of Mono Azo Dye Orange Ii: Catalyst Selection, Reaction Kinetics, And Modeling, Pinar Ozdural

Civil & Environmental Engineering Theses & Dissertations

Wastewaters generated as byproducts of dyeing processes are not treatable with conventional methods. It has been estimated that among the 900,000 tons of different dyes produced annually in the world, approximately 10–15% are lost in wastewater streams during manufacturing and processing operations. Once in rivers and streams, dyes cause major problems, such as reducing light penetration, or displaying toxic effects on aquatic life. Therefore, it is essential that dyes are removed from wastewaters before being discharged into the environment.

This study focuses on the catalytic wet air oxidation (CWAO) of Orange II, a mono azo dye used in large amounts …


Massive Spatiotemporal Watershed Hydrological Storm Event Response Model (Mhserm) With Time-Lapsed Nexrad Radar Feed, Changqing Song Jan 2008

Massive Spatiotemporal Watershed Hydrological Storm Event Response Model (Mhserm) With Time-Lapsed Nexrad Radar Feed, Changqing Song

Civil & Environmental Engineering Theses & Dissertations

Correctly and efficiently estimating hydrological responses corresponding to a specific storm event at the streams in a watershed is the main goal of any sound water resource management strategy. Methods for calculating a stream flow hydrograph at the selected streams typically require a great deal of spatial and temporal watershed data such as geomorphological data, soil survey, landcover, precipitation data, and stream network information to name a few. However, extracting and preprocessing such data for estimation and analysis is a hugely time-consuming task, especially for a watershed with hundreds of streams and lakes and complicated landcover and soil characteristics. To …


Center For Coastal Resources Management Annual Report 2007, Center For Coastal Resources Management Jan 2008

Center For Coastal Resources Management Annual Report 2007, Center For Coastal Resources Management

Reports

No abstract provided.


Summary Tables: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay Jan 2008

Summary Tables: New Kent County, Virginia Shoreline Inventory Report, Marcia Berman, Harry Berquist, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).


New Kent County, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay Jan 2008

New Kent County, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Karen Reay

Reports

The data inventory developed for the Shoreline Inventory is based on a three‑tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. Hand-held GPS units are used to log features observed in the field.

Three GIS coverages are developed …


Comparison Of Career Statistics And Season Statistics In Major League Baseball, Mark Joseph Ammons Jan 2008

Comparison Of Career Statistics And Season Statistics In Major League Baseball, Mark Joseph Ammons

Electronic Theses and Dissertations

This is a comparison of statistics for some of the best seasons and careers of players from Major League Baseball; using data collected on batting average, at bat to homerun ratio, and earned run average. Two teams were created, composed of season leaders and career leaders, chosen for their outstanding offensive and pitching abilities, and were pitted against one another to determine superiority. These two teams also compared against a team from each era of major league baseball. The season and career leaders challenged, the 1918 Boston Red Sox, 1927 New York Yankees, 1955 Brooklyn Dodgers, 1961 New York Yankees, …


Plasma Medicine, Mounir Laroussi, Alexander Fridman Jan 2008

Plasma Medicine, Mounir Laroussi, Alexander Fridman

Electrical & Computer Engineering Faculty Publications

Recent demonstrations of plasma technology in the treatment of living cells, tissues, and organs are creating a newfield at the intersection of plasma science and technology with biology and medicine - Plasma Medicine.


Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray Jan 2008

Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

There is a need for better integration of the fault tolerant and the control designs for safety critical systems such as aircraft. The dependability of current designs is assessed primarily with measures of the interconnection of fault tolerant components: the reliability function and the mean time to failure. These measures do not directly take into account the interaction of the fault tolerant components with the dynamics of the aircraft. In this paper, a first step to better integrate these designs is made. It is based on the observation that unstable systems are intrinsically unreliable and that a necessary condition for …


Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs Jan 2008

Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs

OES Faculty Publications

In-depth studies on the interaction of nonthermal plasmas with microorganisms usually focus on bacteria; only little attention has been given to their effects on more complex eukaryotic cells. We report here nonthermal plasma's effects on cell motility, viability staining, and morphology of eukaryotic microalgae, with three marine dinoflagellates and a marine diatom as major targets. The effects on motility and viability staining depended on the time of exposure to plasma and the species of microalgae. We observed a strong pH decrease in aqueous samples (marine and freshwater algal cultures, their culture media, and deionized water) after exposure to plasma, and …


Nonthermal Laser-Induced Formation Of Crystalline Ge Quantum Dots On Si(100), M. S. Hegazy, H. E. Elsayed-Ali Jan 2008

Nonthermal Laser-Induced Formation Of Crystalline Ge Quantum Dots On Si(100), M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The effects of laser-induced electronic excitations on the self-assembly of Ge quantum dots on Si (100) - (2×1) grown by pulsed laser deposition are studied. Electronic excitations due to laser irradiation of the Si substrate and the Ge film during growth are shown to decrease the roughness of films grown at a substrate temperature of ∼120 °C. At this temperature, the grown films are nonepitaxial. Electronic excitation results in the formation of an epitaxial wetting layer and crystalline Ge quantum dots at ∼260 °C, a temperature at which no crystalline quantum dots form without excitation under the same deposition conditions. …


International Trade In Seafood And Related Products: An Assessment Of U.S. Trade Patterns, James E. Kirkley, John M. Ward, Christopher M. Moore, Christopher Hayes, Brian Hooker, John Walden Jan 2008

International Trade In Seafood And Related Products: An Assessment Of U.S. Trade Patterns, James E. Kirkley, John M. Ward, Christopher M. Moore, Christopher Hayes, Brian Hooker, John Walden

Reports

No abstract provided.


Virginia Game Fish Tagging Program Annual Report 2007, John A. Lucy, Lewis Gillingham Jan 2008

Virginia Game Fish Tagging Program Annual Report 2007, John A. Lucy, Lewis Gillingham

Reports

Initiated in 1995, the Virginia Game Fish Tagging Program (VGFTP) database is comprised of tagged fish records, and corresponding recaptured fish records. These records are primarily generated through contributed efforts of a dedicated corps of trained marine anglers targeting only a select number of target species. The recaptured fish records are the result of observant individuals noticing the tags in live or freshly-boxed/shipped fish. Recapture reports originate from a mix of sources, including marine anglers, commercial fishers, workers in fish packinghouses, wholesale and retail sellers of fish, and NOAA Fisheries observers on coastal trawl boats.


Understanding The Application Of Supported Palladium Catalysts In The Suzuki-Miyaura Cross-Coupling Reaction, Lubabalo Tseliso Bululu Jan 2008

Understanding The Application Of Supported Palladium Catalysts In The Suzuki-Miyaura Cross-Coupling Reaction, Lubabalo Tseliso Bululu

Seton Hall University Dissertations and Theses (ETDs)

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Rigidity And Stability For Isometry Groups In Hyperbolic 4-Space, Youngju Kim Jan 2008

Rigidity And Stability For Isometry Groups In Hyperbolic 4-Space, Youngju Kim

Dissertations, Theses, and Capstone Projects

It is known that a geometrically finite Kleinian group is quasiconformally stable. We prove that this quasiconformal stability cannot be generalized in 4-dimensional hyperbolic space. This is due to the presence of screw parabolic isometries in dimension 4. These isometries are topologically conjugate to strictly parabolic isometries. However, we show that screw parabolic isometries are not quasiconformally conjugate to strictly parabolic isometries. In addition, we show that two screw parabolic isometries are generically not quasiconformally conjugate to each other. We also give some geometric properties of a hyperbolic 4-manifold related to screw parabolic isometries.

A Fuchsian thrice-punctured sphere group has …


Analysis Of Residual Solvents In Pharmaceuticals By Comprehensive Two-Dimensional Gas Chromatography, Cristina Marie Crimi Jan 2008

Analysis Of Residual Solvents In Pharmaceuticals By Comprehensive Two-Dimensional Gas Chromatography, Cristina Marie Crimi

Seton Hall University Dissertations and Theses (ETDs)

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An Embarrassment Of Riches: The Enzymology Of Rna Modification, Dirk Iwata-Reuyl Jan 2008

An Embarrassment Of Riches: The Enzymology Of Rna Modification, Dirk Iwata-Reuyl

Chemistry Faculty Publications and Presentations

The maturation of transfer RNA (tRNA) involves extensive chemical modification of the constituent nucleosides and results in the introduction of significant chemical diversity to tRNA. Many of the pathways to these modified nucleosides are characterized by chemically complex transformations, some of which are unprecedented in other areas of biology. To illustrate the scope of the field, recent progress in understanding the enzymology leading to the formation of two distinct classes of modified nucleosides, the thiouridines and queuosine, a 7-deazaguanosine, is reviewed. In particular, recent data validating the involvement of several proposed intermediates in the formation of thiouridines are discussed, including …


Assessing Stakeholder Preferences For Chesapeake Bay Restoration Options : A Stated Preference Discrete Choice-Based Assessment, Rob Hicks, James Kirkley, Kenneth Mcconnell, Winifred Ryan, Tara Scott, Ivar Strand Jan 2008

Assessing Stakeholder Preferences For Chesapeake Bay Restoration Options : A Stated Preference Discrete Choice-Based Assessment, Rob Hicks, James Kirkley, Kenneth Mcconnell, Winifred Ryan, Tara Scott, Ivar Strand

Reports

Chesapeake 2000 or C2K is a multi-jurisdictional agreement between the states of Virginia, Maryland, Pennsylvania, the District of Columbia, the Chesapeake Bay Commission and the U.S. Environmental Protection Agency, representing the federal government, to restore the health of the Chesapeake Bay’s ecosystem. This agreement commits the participants to achieve five major restoration goals, 22 sub-objectives or categories, and 102 specific commitments or restoration activities. The five major goals are the following: (1) restore and protect natural living resources; (2) restore and protect vital habitat; (3) restore and protect water quality; (4) promote sound land use; and (5) promote stewardship and …


Metal Modulation Epitaxy Growth For Extremely High Hole Concentrations Above 10(19) Cm(-3) In Gan, Gon Namkoong, Elaissa Trybus, Kyung Keun Lee, Michael Moseley, W. Alan Doolittle, David C. Look Dec 2007

Metal Modulation Epitaxy Growth For Extremely High Hole Concentrations Above 10(19) Cm(-3) In Gan, Gon Namkoong, Elaissa Trybus, Kyung Keun Lee, Michael Moseley, W. Alan Doolittle, David C. Look

Applied Research Center Publications

The free hole carriers in GaN have been limited to concentrations in the low 1018 cm−3 range due to the deep activation energy, lower solubility, and compensation from defects, therefore, limiting doping efficiency to about 1%. Herein, we report an enhanced doping efficiency up to ~10% in GaN by a periodic doping, metal modulation epitaxy growth technique. The hole concentrations grown by periodically modulating Ga atoms and Mg dopants were over ~1.5 x 1019 cm−3.

© 2008 American Institute of Physics.


Unit Rectangle Visibility Graphs, Alice M. Dean, Joanna A. Ellis-Monaghan, Sarah J. Hamilton, Greta Pangborn Dec 2007

Unit Rectangle Visibility Graphs, Alice M. Dean, Joanna A. Ellis-Monaghan, Sarah J. Hamilton, Greta Pangborn

Mathematics, Statistics and Computer Science Faculty Research and Publications

Over the past twenty years, rectangle visibility graphs have generated consider- able interest, in part due to their applicability to VLSI chip design. Here we study unit rectangle visibility graphs, with fixed dimension restrictions more closely modeling the constrained dimensions of gates and other circuit components in computer chip applications. A graph G is a unit rectangle visibility graph (URVG) if its vertices can be represented by closed unit squares in the plane with sides parallel to the axes and pairwise disjoint interiors, in such a way that two vertices are adjacent if and only if there is a non-degenerate …


Effect Of Low Concentration Salt On Organic Contact Angle In Ionic Surfactant Solutions: Insight From Theory And Experiment, Samuel Morton, D. Keffer, A. Davis, R. Counce Dec 2007

Effect Of Low Concentration Salt On Organic Contact Angle In Ionic Surfactant Solutions: Insight From Theory And Experiment, Samuel Morton, D. Keffer, A. Davis, R. Counce

Samuel A Morton

No abstract provided.


Cracking And Crumbling: Exploring Mechanisms Of Dike Emplacement, Teaching Structural Geology In The 21st Century, Resources For Teaching Structural Geology, Phillip Resor Dec 2007

Cracking And Crumbling: Exploring Mechanisms Of Dike Emplacement, Teaching Structural Geology In The 21st Century, Resources For Teaching Structural Geology, Phillip Resor

Phillip G Resor

No abstract provided.


'Partial Derivatives: Are You Kidding?': Teaching Thermodynamics Using Virtual Substance, Chrystal Bruce, Carribeth Bliem, John Papanikolas Dec 2007

'Partial Derivatives: Are You Kidding?': Teaching Thermodynamics Using Virtual Substance, Chrystal Bruce, Carribeth Bliem, John Papanikolas

Chrystal D. Bruce

No abstract provided.


Effect Of Electrolyte Concentration On Surfactant Adsorption To At Qcm Immersed In Surfactant + Electrolyte Solutions, S. Ray, R. Counce, Samuel Morton Dec 2007

Effect Of Electrolyte Concentration On Surfactant Adsorption To At Qcm Immersed In Surfactant + Electrolyte Solutions, S. Ray, R. Counce, Samuel Morton

Samuel A Morton

No abstract provided.


Mobile Instructional Laboratory Environments And Their Use In Computing Sciences, Stefan Robila, Bert Wachsmuth, Christelle Scharff, Jeffrey Popyack Dec 2007

Mobile Instructional Laboratory Environments And Their Use In Computing Sciences, Stefan Robila, Bert Wachsmuth, Christelle Scharff, Jeffrey Popyack

Bert Wachsmuth

The term 'mobile instructional laboratory' refers to using mobile computing devices such as notebooks for transforming a classroom into a lab setting with the goal of enhancing the practical experience, interaction and understanding. A major goal in all the computing disciplines is to provide students with hands on activities that will enhance their learning of concepts and their professional experience. As such, CS and IT programs require investments in dedicated laboratories that will support applied activities for most of the courses. Unfortunately, space and other resource limitations usually do not allow for permanent creation of such labs. In parallel, current …


Solution-Processed Trilayer Inorganic Dielectric For High Performance Flexible Organic Field Effect Transistors, Hs Tan, Sr Kulkarni, T Cahyadi, Ps Lee, Sg Mhaisalkar, J Kasim, Zx Shen, F.R. Zhu Dec 2007

Solution-Processed Trilayer Inorganic Dielectric For High Performance Flexible Organic Field Effect Transistors, Hs Tan, Sr Kulkarni, T Cahyadi, Ps Lee, Sg Mhaisalkar, J Kasim, Zx Shen, F.R. Zhu

Professor ZHU, Fu Rong

No abstract provided.


An Sla-Based Auction Pricing Method Supporting Web Services Provisioning, Jia Zhang, Ning Zhang, Liang-Jie Zhang Dec 2007

An Sla-Based Auction Pricing Method Supporting Web Services Provisioning, Jia Zhang, Ning Zhang, Liang-Jie Zhang

Jia Zhang

No abstract provided.