Digital Commons Network^™

Computational Investigation Of The Bioactive Selenium Compounds Ebselen And Selenious Acid, Sonia Antony

Chemistry & Biochemistry Theses & Dissertations

Selenium, a toxic element, is required in trace quantities for the proper functioning of biological systems. The experimental mechanistic study of the reactions of ebselen and selenious acid is difficult due to complexity of the reaction mixtures and the presence of short-lived intermediates. Computational modeling of the reactivity of these species can give us an insight into their mechanisms, but the process is complicated by proton exchanges associated with the mechanistic steps. In gas phase modeling, this may be corrected to a certain level using the solvent assisted proton exchange (SAPE) method. SAPE is a modeling technique that mimics solvent …

Characterizations Of Atmospheric Pressure Low Temperature Plasma Jets And Their Applications, Erdinc Karakas

Electrical & Computer Engineering Theses & Dissertations

Atmospheric pressure low temperature plasma jets (APLTPJs) driven by short pulses have recently received great attention because of their potential in biomedical and environmental applications. This potential is due to their user-friendly features, such as low temperature, low risk of arcing, operation at atmospheric pressure, easy handheld operation, and low concentration of ozone generation. Recent experimental observations indicate that an ionization wave exists and propagates along the plasma jet. The plasma jet created by this ionization wave is not a continuous medium but rather consists of a bullet-like-structure known as "Plasma Bullet". More interestingly, these plasma bullets actually have a …

A Structured Project-Risk Management And Life Cycle Framework For Complex Systems: Ship Repair And Maintenance (Sr&M) Projects, Michael Craig Plumb

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation contributes to insights regarding the implications of using Project Risk Management (PRM) and Life Cycle Assessment (LCA) in managing projects for a complex system. The PRM approach apprehends many forms of risk both internal and external within a given project and assists the manager in determining the level of importance of each individual project phase and component to optimize project success. The life cycle approach to project management is used with short-term limitations with respect to a product's life cycle over several years. The literature discusses many tools and techniques that assist project managers in implementing optimal solutions, …

Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli

Electrical & Computer Engineering Theses & Dissertations

Demands for reliable person identification systems have increased significantly due to highly security risks in our daily life. Recently, person identification systems are built upon the biometrics techniques such as face recognition. Although face recognition systems have reached a certain level of maturity, their accomplishments in practical applications are restricted by some challenges, such as illumination variations. Current visual face recognition systems perform relatively well under controlled illumination conditions while thermal face recognition systems are more advantageous for detecting disguised faces or when there is no illumination control. A hybrid system utilizing both visual and thermal images for face recognition …

Dispersion Or Re-Segregation: A Spatial And Temporal Analysis Of Public Policies And Their Impact On Urban African American Mobility, Brandi Lynette Blessett

Theses and Dissertations in Urban Studies

This study seeks to test Hirsch's second ghetto thesis in the city of Baltimore, Maryland. Hirsch suggested that the role of government, public policies, and administrative discretion were responsible for the re-segregation of African Americans into second ghetto communities in Chicago. Many scholars have used Hirsch's framework to explain ghetto formation. This investigation seeks to extend the literature in several ways. First, several national policies were investigated to determine their impact on African American mobility in Baltimore: the Housing Act of 1937 (public housing), the Housing Act of 1949 (urban renewal), and the Interstate Highway Act of 1956 (transportation). Second, …

Population Dynamics Of Sheepshead (Archosargus Probatocephalus; Walbaum 1792) In The Chesapeake Bay Region: A Comparison To Other Areas And An Assessment Of Their Current Status, Joseph Charles Ballenger

OES Theses and Dissertations

Sheepshead recently have seen an increase in fishing pressure in Virginian waters of the Chesapeake Bay. This increase in fishing pressure has led to demands to install effective management measures to protect the fishery. However, no study regarding the population dynamics, and thus potential yield, of sheepshead has been conducted north of Cape Hatteras. We addressed the need for information regarding the population dynamics of Chesapeake Bay sheepshead by investigating their age distribution, growth rate and reproductive biology. We used this information to construct yield-per-recruit models, which local management agencies may use in the formation of scientifically based management measures. …

The Book Of Memes, Michael Ray Owens

English Theses & Dissertations

The Book of Memes describes the classic battle between free will and mind control. In a process similar to installing new software on a computer, an investigator modifies the behavior of unruly high school students by implantation of new memes, tiny bits of information that regulate human behavior much the same as genes regulate human biology. In short order the students change from thugs to model students. But in the rush to get the job done, the investigator ignores issues such as freedom to choose, and the students are given no choice whether they want new memes or not.

An Extensible Mathematical Model Of Glucose Metabolism, Caleb L. Adams

Mathematics & Statistics Theses & Dissertations

The American Diabetes Association reports that diabetes is the fifth leading cause of death by disease in the United States. An estimated 23.6 million individuals, or seven percent of the population, have diabetes. Nearly one-third are unaware that they have the disease. The total of the direct and indirect medical costs associated with diabetes in 2007 was projected to be $174 billion, or approximately one out of every ten health care dollars.

One must understand the glucose regulatory system of the healthy body to understand diabetes. Blood glucose concentration returns to a constant level after eating and is maintained during …

Long Term Surface Power Generator Design For Mars: Autonomously Deployable Photovoltaic Solar Arrays Along With Regenerative Fuel Cell Modules, Omer Demirok

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis studies the feasibility of incorporating a large autonomously deployed photovoltaic solar array power system as the primary power source for a large fixed Mars base. A mission duration of 10 Earth years has been assumed and the nominal power demands have been specified as a minimum of 40 kW, during daytime operation and a continuous 10 kW. demand for nighttime operation.

The overall system design developed in this thesis has an estimated total mass of 7,400 kg, when utilizing hydrogenated amorphous silicon thin film solar arrays and an estimated total mass of 5,100 kg when utilizing polycrystalline copper-indium-diselenide …

Direct Current Electrokinetic Particle Transport In Micro/Nano-Fluidics, Ye Ai

Mechanical & Aerospace Engineering Theses & Dissertations

Electrokinetics has been widely used to propel and manipulate particles in micro/nano-fluidics. The first part of this dissertation focuses on numerical and experimental studies of direct current (DC) electrokinetic particle transport in microfluidics, with emphasis on dielectrophoretic (DEP) effect. Especially, the electrokinetic transports of spherical particles in a converging-diverging microchannel and an L-shaped microchannel, and cylindrical algal cells in a straight microchannel have been numerically and experimentally studied. The numerical predictions are in quantitative agreement with our own and other researchers' experimental results. It has been demonstrated that the DC DEP effect, neglected in existing numerical models, plays an important …

Evaluation System Design And Academic Performance Analysis Using Clustering And Simulation, Volkan Cakir

Engineering Management & Systems Engineering Theses & Dissertations

The starting point of this study was to understand the possible causes of evaluation system change in a military academic environment. With that motivation the objectives of this study were defined as examining student profiles in a military academy, establishing the nature of academic performance, comparing student groups that were identified by course scores, analyzing student performance changes over time and developing a manageable evaluation system and curriculum by comparing different scenarios.

An analysis was performed on the literature on academic performance prediction, cluster analysis methodologies and their development, and specifically summarized cluster analytic academic performance studies where these two …

A Conceptual Model For Employer Training To Manage Employee Counter-Productive Behaviors, Naomi Spickard Rock

STEMPS Theses & Dissertations

The purpose of this study was to develop a model for employer training to manage employees who possess counter-productive behaviors. With the increasing encouragement for employers to hire without discriminating, the number of individuals with disabilities in the workforce will rise. There is limited training in universities and businesses to teach how to deal with difficult individuals.

Qualitative research in the form of focus groups was conducted. The following research objectives were developed: 1) Identify components of counter-productive behaviors that need to be managed in the workplace. 2) Develop behavioral management strategies that need be learned by employers. 3) Integrate …

Spatially-Explicit Agent-Based Modeling Of Ecosystem Change And Epizootiological Impacts On Caribbean Spiny Lobster, Panulirus Argus, Thomas William Dolan Iii

Biological Sciences Theses & Dissertations

Agent-based models explicitly incorporate interactions and variation at the individual level, just as in the real world. As a result, agent-based models are realistic, intuitive, and generally less complex mathematically than their analytical counterparts. Their primary disadvantage is the large amount of detailed data required to construct and parameterize them. Although the use of agent-based simulation is increasing in ecology, they are highly specific, so are rarely used for development of theory. To demonstrate the flexibility and utility of this approach I developed a multi-species, agent-based, spatially-explicit model of the spiny lobster nursery of southern Florida that incorporates changing salinities, …

Bioinformatics, Thermodynamics And Kinetics Analysis Of An All Alpha Helical Protein With A Gree-Key Topology, Hai Li

Chemistry & Biochemistry Theses & Dissertations

Computational and experimental studies focusing on the role of conserved residues for folding and stability is an active and promising area of research. To further expand our understanding we present the results of a bioinformatics analysis of the death domain superfamily. The death domain superfamily fold consists of six α-helices arranged in a Greek-key topology, which is shared by the all β-sheet immunoglobulin and mixed α/β-plait superfamilies. Our sequence and structural studies have identified a group of conserved hydrophobic residues and corresponding long-range interactions, which we propose are important in the formation and stabilization of the hydrophobic core and native …

A Comparison Of Adrenal In Toad-Eating And Nontoad-Eating Snakes, Shabnam Mohammadi

Biological Sciences Theses & Dissertations

Toads are chemically defended by bufadienolides, a class of cardiotonic steroids lethal to most predators, including many snakes. Bufadienolides bind to Na+K +-ATPase, inhibiting their ability to transport ions. In cardiocytes, this inhibition cause arrhythmia and severely increased contraction strength, which, if prolonged, lead to death. However, several snakes are resistant to bufadienolides and consume toads with no ill effects. Adrenal glands produce hormones that are important for the maintenance of Na+K +ATPase, and may therefore play an important role in countering the negative effects of bufadienolides. Indeed, the toad-eating specialist Heterodon platirhinos has been known to possess enlarged, and …

Modeling The Contagion Effect Of Foreclosures Within The Real Estate Market By Use Of Agent-Based Modeling And Simulation, Marshall William Gangel

Computational Modeling & Simulation Engineering Theses & Dissertations

Over the last several years, the US financial and real estate markets have experienced a significant recession. During this downturn, the number of real estate foreclosures rose drastically. Recent studies have empirically demonstrated a reduction in real estate values due to foreclosures. The observed reduction in the average value of real estate properties has been labeled the foreclosure contagion effect. The foreclosure contagion effect impacts healthy neighboring properties that surround the foreclosed property as a function of time and distance.

This study uses an agent-based modeling and simulation (ABMS} approach to explore the contagion effect of foreclosures. For this research, …

Manipulating Particles For Micro- And Nano-Fluidics Via Floating Electrodes And Diffusiophoresis, Sinan Eren Yalcin

Mechanical & Aerospace Engineering Theses & Dissertations

The ability to accurately control micro- and nano-particles in a liquid is fundamentally useful for many applications in biology, medicine, pharmacology, tissue engineering, and microelectronics. Therefore, first particle manipulations are experimentally studied using electrodes attached to the bottom of a straight microchannel under an imposed DC or AC electric field. In contrast to a dielectric microchannel possessing a nearly-uniform surface charge, a floating electrode is polarized under the imposed electric field.

The purpose is to create a non-uniform distribution of the induced surface charge, with a zero-net-surface charge along the floating electrode's surface. Such a field, in turn, generates an …

Social Networking And Individual Performance: Examining Predictors Of Participation, Michael Anthony Brown Sr.

School of Public Service Theses & Dissertations

This dissertation addresses relationships between social networking and individual performance. The "act" of social networking is a process and practice by which people and organizations are drawn together by family, work or hobby to interact via websites. The explosion of these new network connections in the workplace suggests the need for an exploration of the various ways organizations can affect and improve performance and productivity.

This dissertation suggests a social networking participation model that may help organizations predict and understand the value proposition that affects acceptance or rejection of participation. Innovation adoption, governing by network and social capital are important …

Ionic Current Rectification Phenomena In Asymmetrical Polymer Nanopores Under Salt Gradients, Murat Bakirci

Mechanical & Aerospace Engineering Theses & Dissertations

The magnitude of current through a conical nanopore filled with an electrolyte solution depends on the polarity of the applied bias, indicating an asymmetric diode-like current-voltage (I-V) curve. This kind of phenomenon refers to ionic current rectification (ICR), which is of interest because many ion-channel proteins in cellular membranes are rectifying. In addition, ICR in nanopores can be used to control ion concentrations in nano- and microfluidic systems. In this study, the ICR phenomenon through a conical nanopore simultaneously subjected to an electric field and salt concentration gradient is experimentally and numerically investigated.

The experiments were conducted in an Izon's …

Analysis Of Attitude And Achievement Using The 5e Instructional Model In An Interactive Television Environment, Gamaliel R. Cherry

STEMPS Theses & Dissertations

The purpose of this quasi-experimental study was to examine attitude and achievement among fifth grade students participating in inquiry and lecture-based forms of instruction through interactive television. Participants (N = 260) were drawn from registered users of NASA's Digital Learning Network™. The first three levels of Bloom's Revised Taxonomy were used to measure levels of achievement while the Science Attitude Inventory II was used to measure science attitudes.

Results indicated a significant interaction between inquiry and topic area, as well as achievement for remember, understand, and apply levels of Bloom's Revised Taxonomy. Differences between mean scores were in favor of …

Interface Thermal Resistance Between Liquid Argon And Various Solids, Ziyuan Shi

Mechanical & Aerospace Engineering Theses & Dissertations

Heat conduction between two parallel solid walls separated by liquid argon is investigated using three-dimensional molecular dynamics (MD) simulations. Liquid argon molecules confined in silver and graphite nano-channels are examined separately. Heat flux and temperature distribution within the nano-channels are calculated by maintaining a fixed temperature difference between the two solid surfaces. Temperature profiles are linear sufficiently away from the walls, and heat transfer in liquid argon obeys the Fourier law. The temperature jump due to the interface thermal resistance (i.e., Kapitza length) is calculated by extrapolating the temperature profile in the bulk region on to the wall and is …

The Disappearing Disease, Heather M. Weddington

English Theses & Dissertations

This series of connected essays explores the aesthetic of fragmentation, not as a means to disrupt narrative, but as a means to stretch that narrative. It includes both lyric and traditional forms, along with a series of flash essays that puncture the present action with moments from the past. The essays vary tonally, from the serious to the comic, and though they are connected through first person narration, they are more connected thematically, through an exploration of sexuality, faith, idealism and its loss, and the ways in which gender is performed.

Analysis Of Interband, Intraband, And Plasmon Polariton Transitions In Silver Nanoparticle Films Via In Situ Real-Time Spectroscopic Ellipsometry, S. A. Little, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

The dielectric function of Ag nanoparticle films, deduced from an analysis of in situ real-time spectroscopic ellipsometry (RTSE) measurements, is found to evolve with time during deposition in close consistency with the film structure, deduced in the same RTSE analysis. In the nucleation regime, the intraband dielectric function component is absent and plasmon polariton behavior dominates. Only at nuclei contact, does the intraband amplitude appear, increasing above zero. Both intraband and plasmon amplitudes coexist during surface smoothening associated with coalescence. The intraband relaxation time increases rapidly after surface smoothening is complete, also in consistency with the thin film structural evolution.

Limited Transplantation Of Antigen-Expressing Hematopoietic Stem Cells Induces Long-Lasting Cytotoxic T Cell Responses, Warren L. Denning, Jun Xu, Siqi Guo, Christopher A. Klug, Zdenek Hel

Bioelectrics Publications

Harnessing the ability of cytotoxic T lymphocytes (CTLs) to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs) following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and …

Electroporation-Induced Electrosensitization, Olga N. Pakhomova, Betsy W. Gregory, Vera A. Khorokhorina, Anglela M. Bowman, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

BACKGROUND: Electroporation is a method of disrupting the integrity of cell membrane by electric pulses (EPs). Electrical modeling is widely employed to explain and study electroporation, but even most advanced models show limited predictive power. No studies have accounted for the biological consequences of electroporation as a factor that alters the cell's susceptibility to forthcoming EPs.

METHODOLOGY/PRINCIPAL FINDINGS: We focused first on the role of EP rate for membrane permeabilization and lethal effects in mammalian cells. The rate was varied from 0.001 to 2,000 Hz while keeping other parameters constant (2 to 3,750 pulses of 60-ns to 9-micros duration, 1.8 …

Follicle-Stimulating Hormone Promotes Rank Expression On Human Monocytes, Joseph G. Cannon, Barbara Kraj, Gloria Sloan

School of Medical Diagnostics & Translational Sciences Publications

Elevated serum concentrations of follicle-stimulating hormone (FSH) are associated with diminished bone density in women, beginning years before menopause and the decline in estradiol. We hypothesized that FSH promotes development of myeloid cells toward the bone-resorbing osteoclast phenotype. This was tested by isolating peripheral blood mononuclear cells from nine healthy adults, incubating them in the presence of FSH at three different concentrations spanning the physiological range, and then measuring the expression of receptor activator for NF-κB (RANK, a surface marker for osteoclasts) on CD14+ cells by flow cytometry. In the absence of FSH, 3.3±0.5% of the cells expressed high levels …

Annual Research Report, 2010-2011, Office Of Research

Annual Research Reports

Annual report of collaborative research projects of Old Dominion University faculty and students in partnership with business, industry and government.

Enhancing Simulation Composability And Interoperability Using Conceptual/Semantic/Ontological Models, Andreas Tolk, John A. Miller

Computational Modeling & Simulation Engineering Faculty Publications

(First paragraph) Two emerging trends in Modeling and Simulation (M&S) are beginning to dovetail in a potentially highly productive manner, namely conceptual modeling and semantic modeling. Conceptual modeling has existed for several decades, but its importance has risen to the forefront in the last decade (Taylor and Robinson, 2006; Robinson, 2007). Also, during the last decade, progress on the Semantic Web has begun to influence M&S, with the development of general modeling ontologies (Miller et al, 2004), as well as ontologies for modeling particular domains (Durak, 2006). An ontology, which is a formal specification of a conceptualization (Gruber et al, …

Editor And Journal Information

Virginia Journal of Science

Editorial and submission information for Virginia Journal of Science, vol. 62, no. 4, Winter 2011.

Decomposing The Intergenerational Disparity In Income And Obesity, Qi Zhang, Buhong Zheng, Ning Zhang, Youfa Wang

Community & Environmental Health Faculty Publications

Intergenerational disparity in income and health violates the norm of equal opportunity and deserves the attention of researchers and policy makers. To understand changes in intergenerational disparity, we created the intergenerational mobility index (IMI), which can simultaneously measure changes in income rankings and in health outcomes across two generations. We selected obesity as one health outcome to illustrate the application of IMI due to its severe health and financial consequences for society and the significant changes in the distribution of obesity across income groups. Although obesity has increased in all income groups in the last four decades, higher income groups …