Physical Sciences and Mathematics Commons^™

Http Mailbox - Asynchronous Restful Communication, Sawood Alam

Computer Science Theses & Dissertations

Traditionally, general web services used only the GET and POST methods of HTTP while several other HTTP methods like PUT, PATCH, and DELETE were rarely utilized. Additionally, the Web was mainly navigated by humans using web browsers and clicking on hyperlinks or submitting HTML forms. Clicking on a link is always a GET request while HTML forms only allow GET and POST methods. Recently, several web frameworks/libraries have started supporting RESTful web services through APIs. To support HTTP methods other than GET and POST in browsers, these frameworks have used hidden HTML form fields as a workaround to convey the …

Assessing The Release Of Bioactive Trace Elements From Coal Fly Ash Into Natural Fresh Waters, Candace E. Wall

OES Theses and Dissertations

Each year a significant amount of coal fly ash enters the environment, where it can potentially cause adverse effects by releasing a range of bioactive trace elements. In this context, environmental studies have largely focused on the leaching of trace elements from the coal ash in landfills by rainwater and groundwater, while there has been relatively little study of the release of bioactive trace elements from coal fly ash deposited in natural fresh waters such as rivers and lakes. Furthermore, the batch leaching methods that have been used to study the interaction of rainwater and groundwater with coal ash in …

Evaluating The Contribution Of Groundwater To Wetland Water Budgets Central Piedmont Virginia, Kerby Morgan Dobbs

OES Theses and Dissertations

In the Piedmont region of Virginia, development pressures are increasing the demand for mitigation wetlands but appropriate construction sites are relatively scarce due to local topography and geology. Many existing water budget models used for planned mitigation sites exhibit considerable error when estimating groundwater fluxes, particularly for historical years that lack hydraulic head data. This difficulty has led many planners to neglect or underestimate the contribution of groundwater to wetland water budgets, resulting in mitigation sites that fail to create the appropriate hydrology for the desired vegetation community. However, reliable estimations of groundwater input contributing to wetland water budgets can …

A Multi-Configuration Display Methodology Incorporating Reflection For Real-Time Haptic-Interactive Virtual Environments, Mohammad F. Obeid

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a natural need for real-time min-or reflection in many interactive virtual reality applications to achieve visuo-haptic collocation through optical reflection. Its use, however, calls for adjustments to the original model since a mirror reverses image characteristics. This thesis introduces a design and implementation of a generic configuration component for virtual environments that adjusts image characteristics and haptic interfaces to accommodate various display setups while preserving the correct orientation and properties of the original models in the graphical scene. Four different but related approaches were developed for image connection and are compared and contrasted against primary criteria. The haptic …

Characterization Of Microwave Discharge Plasmas For Surface Processing, Milka Nikolic

Physics Theses & Dissertations

We have developed several diagnostic techniques to characterize two types of microwave (MW) discharge plasmas: a supersonic flowing argon MW discharge maintained in a cylindrical quartz cavity at frequency ƒ = 2.45 GHz and a pulse repetitive MW discharge in air at ƒ = 9.5 GHz. Low temperature MW discharges have been proven to posses attractive properties for plasma cleaning and etching of niobium surfaces of superconductive radio frequency (SRF) cavities. Plasma based surface modification technologies offer a promising alternative for etching and cleaning of SRF cavities. These technologies are low cost, environmentally friendly and easily controllable, and present a …

Modelling Locally Changing Variance Structured Time Series Data By Using Breakpoints Bootstrap Filtering, Rajan Lamichhane

Mathematics & Statistics Theses & Dissertations

Stochastic processes have applications in many areas such as oceanography and engineering. Special classes of such processes deal with time series of sparse data. Studies in such cases focus in the analysis, construction and prediction in parametric models. Here, we assume several non-linear time series with additive noise components, and the model fitting is proposed in two stages. The first stage identifies the density using all the clusters information, without specifying any prior knowledge of the underlying distribution function of the time series. The effect of covariates is controlled by fitting the linear regression model with serially correlated errors. In …

Optimal Control Modeling And Simulation, With Application To Cholera Dynamics, Chairat Modnak

Mathematics & Statistics Theses & Dissertations

The theory of optimal control, a modern extension of the calculus of variations. has found many applications in a wide range of scientific fields, particularly in epidemiology with respect to disease prevention and intervention. In this dissertation. we conduct optimal control modeling, simulation and analysis to cholera dynamics. Cholera is a severe intestinal infectious disease that remains a serious public health threat in developing countries. Transmission of cholera involves complex interactions between the human host, the pathogen, and the environment. The worldwide cholera outbreaks and their increasing severity, frequency and duration in recent years underscore the gap between the complex …

Topics In Electromagnetic, Acoustic, And Potential Scattering Theory, Umaporn Nuntaplook

Mathematics & Statistics Theses & Dissertations

With recent renewed interest in the classical topics of both acoustic and electromagnetic aspects for nano-technology, transformation optics, fiber optics, metamaterials with negative refractive indices, cloaking and invisibility, the topic of time-independent scattering theory in quantum mechanics is becoming a useful field to re-examine in the above contexts. One of the key areas of electromagnetic theory scattering of plane electromagnetic waves — is based on the properties of the refractive indices in the various media. It transpires that the refractive index of a medium and the potential in quantum scattering theory are intimately related. In many cases, understanding such scattering …

Improving The Stability Of High And Low Bandgap Polymers Organic Photovoltaic Devices Using A Solution Based Titanium Sub-Oxide Interfacial Layer, Kurniawan Foe

Electrical & Computer Engineering Theses & Dissertations

The improvement in device efficiency has brought organic photovoltaic (OPV) devices closer to commercial viability, highlighting the importance of studying the lifetime and stability of OPV devices. At present, the lifetime and stability of OPV devices is much shorter and poor mainly caused by oxygen, moisture, and light resulting in the oxidation on low work function electrodes and the degradation of the morphology of the photoactive layer. To improve the lifetime and stability of the OPV devices, we used newly developed low bandgap polymer, PCDTBT, as the electron acceptor material and a solution based titanium sub-oxide (TiOx) interfacial layer inserted …

Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, Av. V. Alakhverdyants, I. Alekseev, S. Bültmann, I. Koraly, Star Collaboration

Physics Faculty Publications

We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v₃, known as triangular flow. The analysis is for charged particles in Au+Au collisions at √sNN=200 GeV, based on data from the STAR experiment at the BNL Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are …

The Connection Between Local Sea Level Rise, Climate Change And Ocean Circulation, Tal Ezer, Larry P. Atkinson

CCPO Publications

In recent years, Norfolk has become a symbol for a city that is already battling the impact of sea level rise (SLR). Street flooding during high tides (Fig. 1, left) is much more common now than in the past, and storm surges (Fig. 1, right) are more severe and last longer. Therefore, as part of Old Dominion University’s Climate Change and Sea Level Rise Initiative (CCSLRI), CCPO scientists focus on studies that enhance our understanding of the causes of local SLR and improve our ability to predict future SLR. This information can help policy makers, insurers, city planners and other …

Fish Species Distribution In Seagrass Habitats Of Chesapeake Bay Are Structured By Abiotic And Biotic Factors, Jason J. Schaffler, Jacques Van Montfrans, Cynthia M. Jones, Robert J. Orth

OES Faculty Publications

Seagrass habitats have long been known to serve as nursery habitats for juvenile fish by providing refuges from predation and areas of high forage abundance. However, comparatively less is known about other factors structuring fish communities that make extensive use of seagrass as nursery habitat. We examined both physical and biological factors that may structure the juvenile seagrass-associated fish communities across a synoptic-scale multiyear study in lower Chesapeake Bay. Across 3years of sampling, we collected 21,153 fish from 31 species. Silver Perch Bairdiella chrysoura made up over 86% of all individuals collected. Nine additional species made up at least 1% …

Optimization Of Solar Cell Arrays Using The Fibonacci Search Algorithm, Felicia Tyyan Farrow

Electrical & Computer Engineering Theses & Dissertations

In our energy hungry world, there is a growing demand to develop creative mechanisms to extract, conserve, and use energy from different resources. The use of solar cells to extract and convert solar energy into electrical energy is a growing and popular field of study because solar energy is clean, free, and renewable. One limitation for photovoltaic (PU) or solar technology is its loss in efficiency and availability as a result of shading or partial shading. Shading or partial shading decreases the total capable output power that the PV system can produce because the array is receiving irradiation from the …

Protein Loop Length Estimation From Medium Resolution Cryoem Images, Andrew R. Mcknight

Computer Science Theses & Dissertations

In the post-genomic era, proteomics research presents a new frontier in life science. Proteins play roles in virtually every biological process, and understanding their atomic structures is the key to unraveling how they carry out their work. Compared to the over half million protein sequences in UniProt, only around 25,000 unique sequences have been atomically modeled and deposited to PDB (Protein Databank). Cryoelectron Microscopy (cryoEM) is an important biophysical technique that produces 3D subnanometer resolution images of molecules not amenable to past approaches like x-ray crystallography or nuclear magnetic resonance. De novo modeling is becoming a promising approach to derive …

Field Emission Studies Toward Improving The Performance Of Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad

Mechanical & Aerospace Engineering Theses & Dissertations

Field emission is the main mechanism that prevents DC high voltage photoemission electron guns from operating at the very high bias voltages required to produce low emittance beams. Gas conditioning is shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. The field emission characteristics of 5 stainless steel electrodes varied significantly upon the initial application of voltage but improved to nearly the same level …

Updating Maryland's Sea-Level Rise Projections, Donald F. Boesch, Larry P. Atkinson, William C. Boicourt, John D. Boon, Donald R. Cahoon, Robert A. Dalrymple, Tal Ezer, Benjamin P. Horton, Zoe P. Johnson, Robert E. Kopp, Ming Li, Richard H. Moss, Adam Parris, Christopher K. Sommerfield

CCPO Publications

With its 3,100 miles of tidal shoreline and low-lying rural and urban lands, "The Free State" is one of the most vulnerable to sea-level rise. Historically, Marylanders have long had to contend with rising water levels along its Chesapeake Bay and Atlantic Ocean and coastal bay shores. Shorelines eroded and low-relief lands and islands, some previously inhabited, were inundated. Prior to the 20th century, this was largely due to the slow sinking of the land since Earth’s crust is still adjusting to the melting of large masses of ice following the last glacial period. Over the 20th century, however, the …

System-Size Dependence Of Transverse Momentum Correlations At √ S N N = 62.4 And 200 Gev At The Bnl Relativistic Heavy Ion Collider, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, S. Bültmann, I. Koralt

Physics Faculty Publications

We present a study of the average transverse momentum (P_t) fluctuations and pt correlations for charged particles produced in Cu+Cu collisions at midrapidity for √sNN= 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the P_t correlation results have been studied as functions of the collision centralities, the ranges in P_t, the pseudorapidity η, and the azimuthal angle ϕ. The square root of the measured P_t correlations when scaled …

Atmospheric Pressure He-Air Plasma Jet: Breakdown Process And Propagation Phenomenon, Asma Begum, Mounir Laroussi, Mohammad Rasel Pervez

Electrical & Computer Engineering Faculty Publications

In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet …

Section Abstracts: Environmental Science

Virginia Journal of Science

Abstracts of the Environmental Science Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Einstein A Coefficients For Rovibronic Lines Of The A2Π → X2Σ+ And B'2Σ+ → X 2Σ+ Transitions Of Mgh, Ehsan Gharibnezhad, Alireza Ahayesteh, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Einstein A coefficients have been calculated for rovibronic lines of the A²Π →X²Σ⁺ and B'²Σ⁺ →X²Σ⁺ transitions of 24MgH. Using the experimentally determined analytic potential energy curve for the X²Σ⁺ state, and the Rydberg-Klein-Rees potentials for the A²Π and B'²Σ⁺ states, combined with the most recent ab initio transition dipole moments, rovibronic transition moments were computed. The rovibronic transition frequencies were obtained accurately by subtracting the published term values of the X²Σ⁺, A²Π and B' …

Section Abstracts: Astronomy, Mathematics And Physics

Virginia Journal of Science

Abstracts of the Astronomy, Mathematics and Physics Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Section Abstracts: Chemistry

Virginia Journal of Science

Abstracts of the Chemistry Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Section Abstracts: Statistics

Virginia Journal of Science

Abstracts of the Statistics Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

Section Abstracts: Computer Science

Virginia Journal of Science

Abstracts of the Computer Science Section for the 91st Annual Virginia Journal of Science Meeting, May 2013

91st Annual Meeting Of The Virginia Academy Of Science: Proceedings

Virginia Journal of Science

Proceedings of the 91st Annual Meeting of the Virginia Academy of Science, held at Virginia Polytechnic Institute and State University, May 22-24, 2013.

Marine Phytoplankton Temperature Versus Growth Responses From Polar To Tropical Waters- Outcome Of A Scientific Community-Wide Study, Philip W. Boyd, Tatiana A. Rynearson, Evelyn A. Armstrong, Feixue Fu, Kendra Hayashi, Zhangxi Hu, David A. Hutchins, Elena Litchman, Margaret R. Mulholland, Uta Passow, Robert F. Stzepek, Kerry A. Whittaker, Elizabeth Yu, Mridul K. Thomas

OES Faculty Publications

“It takes a village to finish (marine) science these days”

Paraphrased from Curtis Huttenhower (the Human Microbiome project)

The rapidity and complexity of climate change and its potential effects on ocean biota are challenging how ocean scientists conduct research. One way in which we can begin to better tackle these challenges is to conduct community-wide scientific studies. This study provides physiological datasets fundamental to understanding functional responses of phytoplankton growth rates to temperature. While physiological experiments are not new, our experiments were conducted in many laboratories using agreed upon protocols and 25 strains of eukaryotic and prokaryotic phytoplankton …

Springtime Contribution Of Dinitrogen Fixation To Primary Production Across The Mediterranean Sea, E. Rahav, B. Herut, A. Levi, Margaret Mulholland, I. Berman-Frank

OES Faculty Publications

Dinitrogen (N-2) fixation rates were measured during early spring across the different provinces of Mediterranean Sea surface waters. N-2 fixation rates, measured using N-15(2) enriched seawater, were lowest in the eastern basin and increased westward with a maximum at the Strait of Gibraltar (0.10 to 2.35 nmol NL-1 d(-1), respectively). These rates were 3-7 fold higher than N-2 fixation rates measured previously in the Mediterranean Sea during summertime and we estimated that methodological differences alone did not account for the seasonal changes we observed. Higher contribution of N-2 fixation to primary production (4-8 %) was measured in the western basin …

Circulation, Vol. 18, No. 2, Center For Coastal Physical Oceanography, Old Dominion University, Malcolm Scully

CCPO Circulation

Spring 2013 issue of CCPO Circulation featuring article "Physical Modulation of Dissolved Oxygen in Chesapeake Bay" by Dr. Malcolm Scully

The Use Of Visual-Based Simulated Environments In Teacher Preparation, Sharon Judge, Jonna Bobzien, Ann Maydosz, Sabra Gear, Petros Katsioloudis

Communication Disorders & Special Education Faculty Publications

While virtual technology for training in the simulation field has a long history in medicine, aviation, and the military, the application of similar emerging and innovative technologies in teacher preparation and education has been limited. TLE TeachLive™ (Teaching Learning Environment, Teaching in a Virtual Environment) [TLE] is an inventive mixed-reality environment (the blending of real and synthetic content) where prospective teachers can interact with a group of virtual students. The purpose of the virtual teaching environment of TLE is to strengthen teacher recruitment, preparation, and retention in education by allowing teachers to improve their skills with virtual students, providing a …

Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag

Computer Science Theses & Dissertations

Vehicular Ad Hoc Networks (VANETs) are a form of Mobile Ad Hoc Networks (MANETs) in which vehicles on the road form the nodes of the network. VANETs provide several services to enhance the safety and comfort of drivers and passengers. These services can be obtained by the wireless exchange of information among the vehicles driving on the road. In particular, the transmission of two different types of messages, safety/update and non-safety messages.

The transmission of safety/update message aims to inform the nearby vehicles about the sender's current status and/or a detected dangerous situation. This type of transmission is designed to …