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Real-Time Measurements On The Effects Of Ultra-Short High Voltage Pulses On Hl-60 Cells, Michalis C. Artemiou

Electrical & Computer Engineering Theses & Dissertations

The application of high voltage microsecond pulses that are above a critical value, to biological cells, has been shown to cause electroporation (Neumann, 1989). In addition, ultra-short pulses of several tens to hundreds of nanoseconds duration have been recently shown to affect intracellular structures without disturbing the plasma membrane (Schoenbach, 2001). However, such ultra-short intense pulses are expected to cause deformation of cells due to Maxwell stresses. This deformation was studied by means of an imaging technique with 10 ns temporal resolution on HL-60 cells. The imaging system consists of an inverted microscope where a spark light source was used …

Fuzzy Modeling Of Electromagnetic Emissions From Portable Electronic Devices Onboard Commercial Aircraft, Madiha Jamil Jafri

Electrical & Computer Engineering Theses & Dissertations

The use of Portable Electronic Devices (PEDs) is prohibited during take-off and landing of an aircraft because PEDs may emit signals that can interfere with the aircraft's navigation and communication systems. The electromagnetic interference (EMI) on the aircraft's electronics due to PEDs emissions is examined for Boeing 737 and 747 aircraft. This work, funded by the NASA Graduate Researchers Program, uses Interference Path Loss (IPL) data, collected by researchers from NASA Langley Research Center, Eagles Wings Inc. and United Airlines on several out-of-service United B737 and B747 airplanes.

B737 and B747 IPL data has been analyzed using a graphical analysis …

Dynamical Studies Of Model Membrane And Cellular Response To Nanosecond, High-Intensity Pulsed Electric Fields, Qin Hu

Electrical & Computer Engineering Theses & Dissertations

The dynamics of electroporation of biological cells subjected to nanosecond, high intensity pulses are studied based on a coupled scheme involving the current continuity and Smoluchowski equations. The improved pore formation energy model includes a dependence on pore population and density. It also allows for variable surface tension and incorporates the effects of finite conductivity on the electrostatic correction term, which was not considered by the simple energy models in the literature. It is shown that E(r) becomes self-adjusting with variations in its magnitude and profile. The whole scheme is self-consistent and dynamic.

An electromechanical analysis based on thin-shell theory …

Genetic Algorithm-Based Model For Determination Of Efficient Management Strategies For Irrigation Canal Networks, Talaat Taher El Gamel

Civil & Environmental Engineering Theses & Dissertations

An optimization model for the determination of efficient management strategies for an irrigation canal network is developed. The objective is to minimize the total water consumed while satisfying various system constraints. An unsteady flow model is used to simulate the flow in the network. A genetic algorithm- (GA-) based framework is used to solve the model. The suitable GA parameters that should be used within the model, as well as the performance of various constraint-handling techniques, are studied. Uncertainties in crop pattern and water consumption rates are incorporated into the search procedure to identify more reliable solutions. A graphical interface …

Anthropogenic Lead Deposition And Four National Parks In Poland As Determined By Lead Isotope Ratios, Shannon Simcoe

OES Theses and Dissertations

Polluted soils are recognized by having high concentrations of heavy metals, including Pb. Partitioning of metals in geochemical fractions, by sequential chemical extractions, may indicate whether a metal has been recently deposited in the soil. While concentration levels alone cannot distinguish between natural and anthropogenic Pb, studies have demonstrated that anthropogenic pollution is accurately recorded by specific Pb isotope signatures, which differ from natural Pb isotopes. The objective of this project was to use ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁶Pb/²⁰⁴Pb isotope ratios to differentiate between the anthropogenic Pb input and the naturally occurring Pb in four national …

Effects Of Ultrasonic And Hand-Activated Scaling On Tactile Sensitivity In Second Year Dental Hygiene Students In A Clinical Setting, Miranda Beeson

Dental Hygiene Theses & Dissertations

The purpose of this study was to determine if time spent instrumenting class III, IV, and V calculus clients, either hand-activated or with an ultrasonic scaler, decreased the tactile sensitivity of the clinician, and if change occurs in index finger, middle finger, and thumb tactile sensitivity prior to and following 45-minute scaling episodes. This study also afforded an opportunity to determine if tactile sensitivity changed in the same dental hygiene students over a one-year period of time by comparing data with that of a similar study conducted in the fall of 2002. Random assignment and a sample size of 25 …

Neural Correlates Of Art Therapy As Indicated Through Electroencephalography, Kerry A. Kruk

EVMS School of Health Professions Theses & Dissertations

Quantitative electroencephalograph (QEEG) reports of 14 healthy women participants engaged in art making in response to two general art therapy directives were generated and compared at Eastern Virginia Medical School. A Cadwell Easy-II 32-channel digital EEG and Physiometrx E-net which contains placements according to the International 10-20 system were used to collect brainwave activity. This study explored the effects of clay sculpting and marker drawing conditions on neural activity in the right and left frontal and parietal cortices.

One aim of the study was to illuminate what Lusebrink (1990) suggested - that different types of media and processes elicit different …

Plato Means Business In The Republic: A Human Resource Management Critique Of The Philosopher-King, Anton Karl Kozlovic

Reconstruction: Studies in Contemporary Culture

[First paragraph]

Exploring the interface between 20th century management principles and the classical world is innovative and relatively new, but not unheard of in the recent past. For example, Greg Latemore and Victor Callan (1998) used Homer's The Odyssey to illustrate leadership lessons. Charles Handy (1995) used four Greek gods (i.e., Zeus, Apollo, Athena, Dionysius) as role models to show managers how to run their own businesses more effectively. While conventional histories of management thought routinely examined the ancient world for its insights, contributions and other ideational antecedence that underpinned their discipline (George Jr., 1972). However, the value of this …

Generating Series For Interconnected Nonlinear Systems And The Formal Laplace-Borel Transform, Yaqin Li

Electrical & Computer Engineering Theses & Dissertations

Formal power series methods provide effective tools for nonlinear system analysis. For a broad range of analytic nonlinear systems, their input-output mapping can be described by a Fliess operator associated with a formal power series. In this dissertation, the inter connection of two Fliess operators is characterized by the generating series of the composite system. In addition, the formal Laplace-Borel transform of a Fliess operator is defined and its fundamental properties are presented. The formal Laplace-Borel transform produces an elegant description of system interconnections in a purely algebraic context.

Specifically, four basic interconnections of Fliess operators are addressed: the parallel, …

Bio-Optical Properties Of The Arctic Waters: Empirical And Theoretical Observations, Jian Wang

OES Theses and Dissertations

Bio-optical observations were made during August 2000 in the Beaufort and Chukchi Seas. Chlorophyll a concentration (Chl) ranged from 0.068 to 18.51 mg chl m⁻³. Both total particulate and phytoplankton absorption at 443 nm were closely correlated with chlorophyll concentration. There is no strong correlation between chlorophyll concentration and absorption by soluble materials or nonpigmented particulates. Absorption, scattering, and attenuation all show strong first-order spectral relationships. Two semianalytical remote sensing reflectance models were evaluated and validated using bio-optical data collected in this region. Both models were proficient at retrieving chlorophyll concentration, phytoplankton absorption coefficients, and particulate backscattering coefficients. …

A Framework For Secure Group Key Management, Sahar Mohamed Ghanem

Computer Science Theses & Dissertations

The need for secure group communication is increasingly evident in a wide variety of governmental, commercial, and Internet communities. Secure group key management is concerned with the methods of issuing and distributing group keys, and the management of those keys over a period of time. To provide perfect secrecy, a central group key manager (GKM) has to perform group rekeying for every join or leave request. Fast rekeying is crucial to an application's performance that has large group size, experiences frequent joins and leaves, or where the GKM is hosted by a group member. Examples of such applications are interactive …

Circulation, Vol. 11, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Chris Powell

CCPO Circulation

Spring 2004 issue of CCPO Circulation featuring article "Technical Requirements for a Real-Time Oceanographic Mooring at LEO-15" by Chris Powell

The Evaluation Of Child Safety Seat Misuse And Driver Training To Increase Correct Use In A Local Community, Michelle Lynn Rose

Psychology Theses & Dissertations

Many researchers have shown that child safety seats are being misused 80 to 85% of the time. In the present study, child safety seat checks were conducted at two local daycare facilities, in which child safety seats were checked for misuse and drivers (at one site) received hands-on training from certified technicians. Hands-on training, for the purposes of this study, was defined as showing drivers mistakes in their seat installations, then having the drivers re-install the seats correctly with coaching by the technicians. For the first phase of checks, there were 67 drivers who participated (22 from the trained Site …

Computational Sensing And Active Flow Control Of Airfoil At Stall Conditions, Ersin Gercek

Mechanical & Aerospace Engineering Theses & Dissertations

During airfoil stall condition, the flow over airfoil loses its momentum, creating high pressure zones and adverse pressure gradients on the airfoil upper surface. When the adverse pressure forces and viscous forces get greater than the flow momentum, the flow can no longer remain attached on the surface and separates towards a low pressure zone.

In order to eliminate separation, the low momentum flow on the suction side should be predicted and removed from the airfoil surface to maintain high momentum and low pressure flow conditions over the airfoil. This study is conducted to apply active computational sensing and control …

An Empirical Examination Of The Moderators Of The Service Recovery Paradox, Vincent P. Magnini

Theses and Dissertations in Business Administration

Some researchers (Abrams and Paese, 1993; Bitner, Booms, and Tetreault, 1990; Etzel and Silverman. 1981; Feinberg et al., 1990; Folkes and Kotsos, 1986; Gilly and Gelb, 1982; Hart, Heskett, and Sasser, 1990; Hocutt, Chakraborty, and Mowen, 1997; Kelley and Davis, 1994; Kelley, Hoffman and Davis, 1993; McCollough and Bharadwaj, 1992; Michel, 2001; Chrage, 2001; Smith and Bolton, 1998; Spreng, Harrell, and Mackoy, 1995; Tax, Brown, and Chandrashekaran, 1998) support the notion of a ‘recovery paradox’ which states that the occurrence of a failure may, if the recovery is effective, offer an opportunity to acquire higher satisfaction ratings from customers than …

Speaker Normalization For Improved Automatic Speech Recognition For Digital Libraries, Wei Wang

Electrical & Computer Engineering Theses & Dissertations

The context of this thesis work is the improvement of automatic speech recognition (ASR) for use with digital libraries. First, commonly used multimedia file formats and codecs are surveyed with the objective of identifying those formats that preserve speech quality while keeping file sizes compact. The main contribution of the work is a new technique for speaker adaptation based on frequency scale modifications. The frequency scale is modified using a minimum mean square error matching of a spectral template for each speaker to a "typical speaker" spectral template. Each spectral template is computed from the average amplitude-normalized spectra of several …

A Comparative Study Of American-Born Chinese And Non American-Born Chinese Students' Language Learning Motivation, Language Acquisition, And Ethnic Identity Development In Chinese Language Schools, Sarah C. Tsai

Theses and Dissertations in Urban Services - Urban Education

This dissertation is a non-experimental comparative and correlational study. It compares the three variables of language learning motivation, language acquisition, and ethnic identity between American-Born Chinese (ABC) and Adopted Chinese students (Non-ABC) at Association of Chinese language schools on the East Coast of the United States. One hundred and eighty-two ABC and 70 non-ABC students enrolled in Chinese language classes in the fall semester of 2004 participated in this study. Additionally, this study identifies the teaching categories that are most commonly applied in the Chinese language school classroom.

The data were collected through a survey method. The research instruments used …

The Effects Of An Autobiographical Dialogue Journaling Activity On Student Teachers' Levels Of Cultural Sensitivity And Reflective Skills, Wanda G. Lastrapes

Theses and Dissertations in Urban Services - Urban Education

The purpose of this study was to examine the influence of a researcher-designed autobiographical dialogue journaling activity on student teachers' levels of cultural sensitivity and levels of reflection. Written feedback from the university supervisors and cooperating teachers was analyzed to identify differences and similarities in the structure and focus of their responses.

Data was collected from 30 student teachers assigned to urban elementary field placements following a six-week structured journaling activity. Student teachers were randomly assigned to one of three journaling conditions: autobiographical dialogue journaling with their cooperating teacher, autobiographical dialogue journaling with their university supervisor, or the traditional student …

Microdischarge Arrays, Wenhui Shi

Electrical & Computer Engineering Theses & Dissertations

Microhollow cathode discharges (MHCDs) are DC or pulsed gas discharges between two electrodes, separated by a dielectric, and containing a concentric hole. The diameter of the hole, in this hollow cathode configuration, is in the hundred-micrometer range. MHCDs satisfy the two conditions necessary for an efficient excimer radiation sources: (1) high energy electrons which are required to provide a high concentration of excited or ionized rare gas atoms; (2) high pressure operation which favors excimer formation (a three-body process). Flat panel excimer sources require parallel operation of MHCDs. Based on the current-voltage characteristics of MHCD discharges, which have positive slopes …

Relating Water And Otolith Chemistry In Chesapeake Bay, And Their Potential To Identify Essential Seagrass Habitats For Juveniles Of An Estuarine-Dependent Fish, Spotted Seatrout (Cynoscion Nebulosus), Emmanis Dorval

Biological Sciences Theses & Dissertations

A quantitative understanding of habitat use of estuarine-dependent fishes is critical to the conservation of their most essential habitats. Because recruitment and fitness may be influenced by the quality of juvenile habitats, developing methods to quantify habitat-specific survivorship is pivotal to such understanding. An initial step to quantify survivorship is to validate the habitat-specific natural tags contained in otoliths. To this aim I investigated the variability in the chemistry of surface waters and otoliths of juvenile spotted seatrout, Cynoscion nebulosus, in five seagrass habitats of Chesapeake Bay, namely: Potomac, Rappahannock, York, Island, and Eastern Shore. I measured Mg, Ca, …

Role Of Nanophase Oxides In Short-Term Atmospheric Corrosion Of Structural Steels, Rama Balasubramanian

Physics Theses & Dissertations

Systematic studies on the development of nanophase iron oxides in the corrosion products of carbon and weathering steel were performed to understand the role of nanophase oxides in short-term atmospheric corrosion. Similarities and/or differences between short-term and long-term atmospheric corrosion were established by studying carbon steel and weathering steel coupons exposed in mild marine environments for short-term and comparing it with previously established long-term data. Influence of substitutional elements, in particular chromium, in forming nanophase goethite was investigated. Crystallographic, magnetic and morphological properties of nanophase chromium substituted goethite have been characterized in order to understand the protective nature of chromium-substituted …

Spin Structure Functions Of The Deuteron Measured With Clas In And Above The Resonance Region, Kahanawita G. Vipuli G. Dharmawardane

Physics Theses & Dissertations

Spin structure functions of the nucleon in the region of large x and small to moderate Q² continue to be of high current interest. The first moment of the spin structure function g₁, Γ₁, goes through a rapid transition from the photon point (Q² = 0), where it is constrained by the Gerasimov-Drell-Hearn sum rule, to the deep inelastic limit where it is sensitive to the nucleon spin fraction carried by quarks. The interesting behavior in the transition region is dominated by baryon resonance excitations. We concluded an experiment to measure these observables …

Some Aspects Of Deeply Virtual Compton Scattering, Elena Kuchina

Physics Theses & Dissertations

We consider different aspects of the virtual Compton amplitude in QCD on two examples: small-x physics accessible in the Regge regime and twist-3 approximation in the description of DVCS through the general parton distributions. Using this model, we give an estimate for the cross section of deeply virtual Compton scattering for the kinematics of CEBAF at Jefferson Lab.

Electron Scattering From A High Momentum Neutron In Deuterium, Alexei V. Klimenko

Physics Theses & Dissertations

The deuterium nucleus is a system of two nucleons (proton and neutron) bound together. The configuration of the system is described by a quantum-mechanical wave function and the state of the nucleons at a given time is not known a priori. However, by detecting a backward going proton of moderate momentum in coincidence with a reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred if we assume that the proton was a spectator to the reaction. This method, known as spectator tagging, was used to study the electron scattering from high-momentum neutrons …

Neutron Star Electromagnetic Field Structure, Hugh O. Thurman Iii

Physics Theses & Dissertations

This dissertation investigates the neutron star magnetic field from generation to radiation production. We have investigated the spontaneous magnetization process to explain the magnetic field generation. This magnetization is then applied to determine the electromagnetic field structure of the neutron star. As an application of these two calculations, we briefly investigate several radiation mechanisms that are closely related to stellar magnetic fields.

Neutron star magnetic field generation is studied through the spontaneous magnetization process. This process was studied in the non-relativistic, ultra-relativistic, and rigorous relativistic dispersion regimes for the neutrons. Both analytical and numerical approaches show that a phase transition …

Models, Composability, And Validity, Eric Werner Weisel

Computational Modeling & Simulation Engineering Theses & Dissertations

Composability is the capability to select and assemble simulation components in various combinations into simulation systems to satisfy specific user requirements. The defining characteristic of composability is the ability to combine and recombine components into different simulation systems for different purposes. The ability to compose simulation systems from repositories of reusable components has been a highly sought after goal among modeling and simulation developers. The expected benefits of robust, general composability include reduced simulation development cost and time, increased validity and reliability of simulation results, and increased involvement of simulation users in the process. Consequently, composability is an active research …

Prediction Of Rigid Body Aircraft Acceleration Response Due To Atmospheric Disturbances, Billy Keith Buck

Mechanical & Aerospace Engineering Theses & Dissertations

Methodology to predict aircraft transient motion resulting from flight within an unsteady atmospheric environment, coupled with validation using flight test data is proposed. A family of five linear dynamic models is developed for describing the normal acceleration throughout an aircraft cabin due to vertical gust excitation. The five models successively build upon each other by incorporating higher fidelity gust penetration effects while simultaneously maintaining a unified modeling framework. Six wind fields reconstructed from flight test data are used to excite the vehicle models. Simulation responses are compared with forward, center, and aft accelerometer response data recorded during the test. Each …

The Relationship Of Project Team Attributes To Project Interim Performance, Vickie S. Parsons

Engineering Management & Systems Engineering Theses & Dissertations

The factors associated with project success, or failure, have not been conclusively resolved in the project management literature. The purpose of this research was to investigate the relationship of project team attributes and interim project performance using a statistical research design. An abundance of research has focused solely on the importance of technical project components as they relate to cost, schedule, or technical performance. However, research into internal team attributes has been sporadic and, generally, associated with subjective measures of project performance or less than optimal statistical techniques. Prior assessment of project performance has also been concentrated at project completion. …

Scaling And Characterization Of Direct Current Glow Discharge Plasma In Atmospheric Air, Abdel-Aleam Hefney Mohamed

Electrical & Computer Engineering Theses & Dissertations

A microhollow cathode discharge was used as a plasma cathode to sustain a stable direct current glow discharge in atmospheric pressure air. The volumetric scale of glow discharge increased from the millimeter to the centimeter range by extending the plasma in lateral and axial directions. In the axial direction, the length of the glow discharge column was varied from 1 mm to 2 cm, with the sustaining voltage increasing linearly with the glow discharge column length. Extension in the lateral direction was obtained by operating discharges in parallel. The glow discharge plasma of the parallel discharge columns was found to …

Culture Of Growth: Teacher Collaboration For The Empowerment Of All Students, Kamilla Bahbahani

Theses and Dissertations in Urban Studies

This dissertation documents an in-depth year long qualitative case study of three elementary school teachers to address the following research question: what characterizes, and what are the major influences on, an integrated, constructivist-oriented approach to elementary math instruction? The researcher, working collaboratively with the teachers, used a combination of interviews, observations, journaling, and informal discourse to learn about what they want to do in their classes, the various pressures they feel for performance and student learning, the forces they balance in making their instructional choices, and the ways in which they make instructional choices and change their approaches over time. …