Digital Commons Network^™

Development Of Diagnostic Approaches To Determine Sources Of Anthropogenic Stress Affecting Benthic Community Conditions In The Chesapeake Bay, Daniel M. Dauer, Michael F. Lane, Roberto J. Llansó

Benthic Applications

Benthic macrofauna are an important component of estuarine ecosystems. These organisms are a food source for higher trophic levels including fishes and crabs (Virnstein 1977, 1979; Holland et al. 1980; Dauer et al. 1982) and birds (Botton 1984; Quammen 1984). Benthic macrofauna affect both the physical and chemical properties of the sediment and the overlying water column (e.g., Rhoads and Young 1970; Rhoads 1973; Aller 1978, 1980), influence nutrient cycling (Rowe et al 1975; Zeiteschel 1980; Flint and Kamykowski 1984), and are capable of directly controlling phytoplankton biomass in the water column (Cleorn 1982; Officer et al 1982; Cohen et …

A Formal Object Model For Layered Networks To Support Verification And Simulation, Rasha M. B. E. Morsi

Electrical & Computer Engineering Theses & Dissertations

This work presents an abstract formal model of the interconnection structure of the Open Systems Interconnection Reference Model (OSI-RM) developed using Object-Oriented modeling principles permitting it to serve as a re-usable platform in supporting the development of simulations and formal methods applied to layered network protocols. A simulation of the object model using MODSIM III was developed and Prototype Verification System (PVS) was used to show the applicability of the object model to formal methods by formally specifying and verifying a Global Systems for Mobile communications (GSM) protocol. This application has proved to be successful in two aspects. The first …

A Study Of Professional Development School Program Graduates Through Their First Year As Urban School Teachers, Amy J. Vereen

Theses and Dissertations in Urban Services - Urban Education

This year-long study focused on three first-year teachers-in order to examine how they adjusted to their first year, how they developed professionally, and how they changed as teachers. Each teacher possessed characteristics for success in urban schools, and had completed a Professional Development School internship.

Using a self-efficacy test, interviews, and a teacher survey, the three teachers were measured throughout the academic year with regard to their level of readiness to teach, the impact of their Professional Development School training on their work as teachers, self-efficacy, and willingness to continue teaching in an urban setting.

Regarding their level of readiness …

Vertical Distributions Of Zooplankton At The Mouth Of Chesapeake Bay And Calibration Of Backscatter From An Acoustic Doppler Current Profiler, Arthur Keith Jenkins

Biological Sciences Theses & Dissertations

This study investigated the physical factors influencing the vertical distribution of zooplankton at the mouth of the Chesapeake Bay and attempted to derive biological data from acoustic Doppler current profiler (ADCP) backscatter. A single site was occupied in the North Channel at the mouth of Chesapeake Bay (37° 04' N, 75° 58' W) from 17.0–19.7 November 1999. Temperature, salinity, fluorescence, light transmission, current velocity and backscatter were measured throughout the sampling period. Plankton samples were collected every hour from 3.5, 7.5, and 11.5 m.

We found little association between ADCP backscatter and plankton concentrations, but stronger correlations between backscatter and …

Association Of 3d Visualization With Discrete Event Simulation, Krishna Chaitanya Kunam

Electrical & Computer Engineering Theses & Dissertations

Three-dimensional visualization provides simulation users with imagery that is closely related to their direct human experience. 3D visualization of simulations therefore has several advantages: it assists the developer in verifying and debugging the simulation; it often aids the analyst in gaining a better understanding of system performance; and it is especially important in explaining simulation results to the customer. This work presents a method of associating 3D visualizations to discrete event simulations for process simulations. A software system called 3DGen is developed that automates the process of generating a 3D visualization for a discrete event simulation. The 3DGen system is …

Styrene Monomer Solubility In Artificial And Natural Seawaters Of The Lower Chesapeake Bay, Eric Joseph Miller

Chemistry & Biochemistry Theses & Dissertations

Used for making a variety of plastic products, styrene monomer is an aromatic hydrocarbon frequently shipped in bulk quantities through the Port of Hampton Roads, Virginia. Despite its common use around the world and its high aquatic toxicity, little research has been conducted on the chemical's aqueous solubility and reactions during a major spill. In this study, the solubility of styrene monomer was measured in artificial seawater and natural waters collected from four sites on the lower Chesapeake Bay and Elizabeth River. The samples represented a range of different water chemistries in terms of salinity (13.8 — 29.0%) and the …

Production Of A Monoclonal Antibody Against Benzo[Α]Pyrene Diol Epoxide Dna Adducts, Brian Peden Austin

Chemistry & Biochemistry Theses & Dissertations

Benzo[α]pyrene is a ubiquitous pollutant produced from the incomplete combustion of organic material such as fossil fuels. It is found in the workplace, urban air, drinking water, and the food supply. Recently, it has been proposed that benzo[α]pyrene may be the causative agent in the formation of lung adenocarcinomas among some Taiwanese women exposed to cooking oil fumes without adequate ventilation. In this study, calf thymus DNA was modified in vitro with benzo[α]pyrene-diol epoxide (BPDE) to a level consistent with that found in biological samples. This DNA of low modification was used as an immunogen in the production of a …

Generic Cost Estimation Framework For Design And Manufacturing Evaluation, Uday A. Kilkami

Mechanical & Aerospace Engineering Theses & Dissertations

A major drawback of current cost estimation models is their incapability of embracing effectively complete product development stage. Parametric estimation works well in early stages of design, but in detail design stage, a more complete estimation is provided by process model based and detail estimation techniques. A major paradigm shift is proposed in this work whereby ‘Cost’ is to be considered as a design parameter from scientific perspective, and it is to be treated as a design consequence rather than as an operational outcome. A comprehensive framework using System Analysis fundamentals is designed to study ‘Process Cost’ aspects of part …

The Effects Of Technology On Urban High School Students' Sense Of Classroom Community, Mervyn J. Wighting

Theses and Dissertations in Urban Services - Urban Education

This study measured the sense of classroom community among students from two different grades in an independent urban high school (N = 181). A standardized instrument was used to compare sense of community in classes whose teachers used computers frequently and consistently in their instruction with others in which the teachers seldom or never included computer use in the classroom. Quantitative analysis revealed that there was a significant difference between the classes in terms of one of the sub-scales of the instrument; students whose teachers used computers frequently and consistently scored higher on the learning sub-scale of the sense …

Spin Structure Functions Of The Deuteron, Junho Yun

Physics Theses & Dissertations

Inclusive double spin asymmetries have been measured in [special characters omitted] using the CLAS detector and a polarized [special characters omitted] target at. Jefferson Lab in 1998. The goal of these measurements is to study the spin structure of the deuteron and the neutron in the low Q² transition region between the real photon point, where the Gerasimov-Drell-Hearn (GDH) sum rule is expected to be satisfied, and the deep inelastic scattering limit. The analysis and the results for virtual photon asymmetries, the spin structure function [special characters omitted] and its first moment within a Q² range of 0.2 …

External Aerodynamics Of Heavy Ground Vehicles: Computations And Wind Tunnel Testing, Ilhan Bayraktar

Mechanical & Aerospace Engineering Theses & Dissertations

Aerodynamic characteristics of a ground vehicle affect vehicle operation in many ways. Aerodynamic drag, lift and side forces have influence on fuel efficiency, vehicle top speed and acceleration performance. In addition, engine cooling, air conditioning, wind noise, visibility, stability and crosswind sensitivity are some other tasks for vehicle aerodynamics. All of these areas benefit from drag reduction and changing the lift force in favor of the operating conditions. This can be achieved by optimization of external body geometry and flow modification devices. Considering the latter, a thorough understanding of the airflow is a prerequisite.

The present study aims to simulate …

Antecedents And Consequences Of Consumer Ethnocentrism Across Russia's Three Sub-Cultures, Shawn Thelen

Theses and Dissertations in Business Administration

Shimp and Sharma (1987) extended the concept of ethnocentrism to commercial products with the development of a 17-item Consumer Ethnocentrism Scale [CETSCALE]. Consumer ethnocentrism is the belief that purchasing imported products harms the local economy, increases unemployment, and is morally wrong (Skimp and Sharma 1987). Shimp and Sharma (1987) called for studies to determine antecedents to consumer ethnocentrism and to apply the CETSCALE across geographic and regional segments. This dissertation addresses a void in the literature by examining antecedents; Inglehart's Materialism/Post Materialism (1977) and Holbrook's Nostalgia (1993), and outcome variables; product purchase preference, of consumer ethnocentrism across sub-cultures postulated to …

The Development Of An Enterprise Supply Chain Model For Naval Warship Construction, Rex A. Wallen

Computational Modeling & Simulation Engineering Theses & Dissertations

The utilization of computer simulation in the shipbuilding industry is not a new concept and many shipyards in the US and around the world are using simulation tools in a variety of ways with various levels of success. In other industries, computer simulation has proven itself as a powerful tool for reducing non-value added activities and promises to become more prominent in its use as a resource management tool. Its use in the manufacturing of outfitting components in the construction of Naval warships has had limited success due mainly to the inherent nature of ship construction, especially shipyards engaged in …

Modeling Aspects Of Magnetic Actuators And Magnetic Suspension Systems, V. Dale Bloodgood Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation is a study of new modeling techniques developed for magnetic suspension systems. The techniques discussed are modifications of magnetic circuit theory and fundamental eddy current models. The techniques are compared against experimental test results and finite element data. The information gained from the experimental testing is used to provide insight into magnetic bearing design.

A small-gap modeling technique called extended circuit theory is developed that incorporates information about the system gained from finite element data, or experimental data, to be included in the analytic model. The variations between the classical magnetic circuit model and the finite element model …

Chipping Away At The Gendered Wall Implications For Being A Woman Sociologist, Rebecca Fogerty Grove

Sociology & Criminal Justice Theses & Dissertations

The purpose of this study was to investigate what factors may determine productivity among sociology professors and factors that-affect promotions and hiring. In today's academic institutions, the gender barrier is considered nonexistent; however, the actual existence of the gender barrier is often apparent in departmental hiring decisions and university tenure policies. With knowledge of current, often subtle, biased standards, the gender barrier can begin to be dismantled to offer true equality for all potential and current professors. The data was collected in 2001, during the fall academic semester from departments of sociology (n=2 l 8). This thesis looks at the …

Improvements In Wavelength Modulation Spectroscopy Using Ratios Of Higher Harmonics, James Michael Barrington

Electrical & Computer Engineering Theses & Dissertations

Experiments in Wavelength Modulation Spectroscopy have been conducted at Old Dominion University since 1996. The method provides a highly sensitive, nonintrusive method of probing gases. Research has concentrated on effectively modeling the higher harmonic shapes that are measured experimentally. Accurately modeling these signals will result in the ability to reliably extract the information contained in transition line shapes.

In order to accurately depict the signals, the theory must be thoroughly understood. This thesis develops the theory of Wavelength Modulation Spectroscopy from two aspects: a direct Fourier series expansion of a time varying intensity profile and through communication theory. In addition, …

Embedded Software Programming To Develop A Command Line User Interface For Monitoring And Debugging A Manually Driven Gas Regulator Control System, Syed N. Hyder

Electrical & Computer Engineering Theses & Dissertations

This thesis presents a complete embedded programming model and software codes for a command-line user interface for CONCOA's gas regulator control system. Control Corporation of America (CONCOA) manufactures high-pressure gas regulators, which mechanically control the pressure at their outlets. Since the control system is based on mechanical regulators, adding or stopping gas flow from the system can cause manifold fluctuation that could further cause the pressure to rise or fall with time. The main motivation for developing a command line user interface is to provide a centralized computer control to monitor and debug the gas regulator control system electronically by …

Traffic Simulation Using Arena, Shanti Yelamanchi

Electrical & Computer Engineering Theses & Dissertations

Many traffic simulation tools exist for developing traffic simulations; these tools can be divided broadly into two categories — macro simulation tools and micro simulation tools. These two categories of simulation tools are directed at modeling the extremes of traffic systems: very large systems and very small systems. There is a class of intermediate-sized transportation networks for which neither category of simulation tools might perform adequately. Additionally these specialized traffic simulation tools have a high learning curve. For developing medium sized traffic simulations in a short period of time, one might choose to use a familiar general-purpose discrete event simulation …

Robust Face Representation And Recognition Under Low Resolution And Difficult Lighting Conditions, Mohammad Moinul Islam

Electrical & Computer Engineering Theses & Dissertations

This dissertation focuses on different aspects of face image analysis for accurate face recognition under low resolution and poor lighting conditions. A novel resolution enhancement technique is proposed for enhancing a low resolution face image into a high resolution image for better visualization and improved feature extraction, especially in a video surveillance environment. This method performs kernel regression and component feature learning in local neighborhood of the face images. It uses directional Fourier phase feature component to adaptively lean the regression kernel based on local covariance to estimate the high resolution image. For each patch in the neighborhood, four directional …

Decomposition Of Carbon Dioxide In A Capacitively Coupled Radio Frequency Discharge, Thao Hoang Dinh

Physics Theses & Dissertations

Decomposition of CO₂ was studied in a capacitively coupled radio frequency discharge using Martian Simulant Gas mixture that contains 95% CO₂. The discharge was operated at a gas pressure of 3 to 6 Torr and a discharge power density of less than 2.0 W/cm³. The main mechanism of the CO₂ decomposition process is the electron impact dissociation and the rate of the process depends on the electron density, Ne, the concentration of CO₂, and the reduced electric field, E/N. A self-consistent model was established to describe the CO …

The Effect Of Model Formulation On The Comparative Performance Of Artificial Neural Networks And Regression, Michael F. Cochrane

Engineering Management & Systems Engineering Theses & Dissertations

Multiple linear regression techniques have been traditionally used to construct predictive statistical models, relating one or more independent variables (inputs) to a dependent variable (output). Artificial neural networks can also be constructed and trained to learn these complex relationships, and have been shown to perform at least as well as linear regression on the same data sets. Research on the use of neural network models as alternatives to multivariate linear regression has focused predominantly on the effects of sample size, noise, and input vector size on the comparative performance of these two modeling techniques. However, research has also shown that …

A Rf Discharge Cell For Saturated Absorption Spectroscopy Of Metastable Argon, C. I. Sukenik, H. C. Busch

Physics Faculty Publications

We have produced a rf discharge in 40Ar and used saturated absorption spectroscopy to offset lock a Ti:Sapphire laser to the absorption peak of the 43P243D3 cooling transition at 811 nm. We describe the procedure for fabrication of the cell and production of the discharge.

A Task Process Pre-Experimental Model, Holly A. H. Handley, Alexander H. Lewis

Engineering Management & Systems Engineering Faculty Publications

The Adaptive Architectures for Command and Control (A2C2) program is a multidisciplinary program that employs a scientific basis for designing and analyzing adaptive and reconfigurable organizational structures at the Joint Task Force level. As part of its unique model-driven experimentation method, a pre-experimental model is created to support the formulation of hypotheses, the determination of key variables and parameter values, and the prediction of organizational performance. The pre-experimental model is used to explore the parameters of the experimental design in order to determine the appropriate region to conduct officer-in-the-loop experiments at the Naval Postgraduate School. A pre-experimental model based on …

Old Dominion University Library: History, Jean A. Major

University History Bookshelf

A history of the library at Old Dominion University, written by Jean A. Major, University Librarian 1992-2002.

Four Anharmonic Oscillators On A Circle, J. N. Boyd, R. G. Hudepohl, P. N. Raychowdhury

Virginia Journal of Science

Four identical, uniformly separated particles interconnected by ideal anharmonic springs are constrained to move on a fixed, frictionless circular track. The Lagrangian for the system is written and then transformed by matrix operations suggested by the symmetry of the arrangement of springs and particles. The equations of motion derived from the transformed Lagrangian yield four natural frequencies of motion.

Environmental Factors Contributing To The Disaggregation Of A Colonial Cyanoprokaryote And Its Influence On Picoplankton Abundance Within Lake Joyce, Virginia, Lewis F. Affronti Jr., B. Thomas Duquette

Virginia Journal of Science

A colonial cyanoprokaryote, Aphanocapsa holsatica and autotrophic picoplankton abundance were monitored weekly over a two year period in Lake Joyce, Virginia. Significant differences were observed in both the cyanoprokaryote and picoplankton abundance over the study period and an inverse relationship was observed between these two plankton groups. Disaggregation of colonies was shown to contribute to picoplankton populations where water temperature and precipitation input apparently trigger colony dispersion. This relationship is suggested to occur in other aquatic habitats. Results of this work and its implications for ecosystem dynamics are discussed.

Improved Energy Model For Membrane Electroporation In Biological Cells Subjected To Electrical Pulses, R. P. Joshi, Q. Hu, K. H. Schoenbach, H. P. Hjalmarson

Bioelectrics Publications

A self-consistent model analysis of electroporation in biological cells has been carried out based on an improved energy model. The simple energy model used in the literature is somewhat incorrect and unphysical for a variety of reasons. Our model for the pore formation energy E(r) includes a dependence on pore population and density. It also allows for variable surface tension, incorporates the effects of finite conductivity on the electrostatic correction term, and is dynamic in nature. Self-consistent calculations, based on a coupled scheme involving the Smoluchowski equation and the improved energy model, are presented. It is shown that E(r) becomes …

Collisional And Radiative Processes In High-Pressure Discharge Plasmas, Kurt H. Becker, Peter F. Kurunczi, Karl H. Schoenbach

Bioelectrics Publications

Discharge plasmas at high pressures (up to and exceeding atmospheric pressure), where single collision conditions no longer prevail, provide a fertile environment for the experimental study of collisions and radiative processes dominated by (i) step-wise processes, i.e., the excitation of an already excited atomic/molecular state and by (ii) three-body collisions leading, for instance, to the formation of excimers. The dominance of collisional and radiative processes beyond binary collisions involving ground-state atoms and molecules in such environments allows for many interesting applications of high-pressure plasmas such as high power lasers, opening switches, novel plasma processing applications and sputtering, absorbers and reflectors …

Electrical Network-Based Time-Dependent Model Of Electrical Breakdown In Water, R. P. Joshi, J. Qian, K. H. Schoenbach

Bioelectrics Publications

A time-dependent, two-dimensional, percolative approach to model dielectric breakdown based on a network of parallel resistor–capacitor elements having random values, has been developed. The breakdown criteria rely on a threshold electric field and on energy dissipation exceeding the heat of vaporization. By carrying out this time-dependent analysis, the development and propagation of streamers and prebreakdown dynamical evolution have been obtained directly. These model simulations also provide the streamer shape, characteristics such as streamer velocity, the prebreakdown delay time, time-dependent current, and relationship between breakdown times, and applied electric fields for a given geometry. The results agree well with experimental data …

Research In Technology Education: Back To The Future, Philip A. Reed

STEMPS Faculty Publications

No abstract provided.