Digital Commons Network^™

A Potentiometric Gaseous Hydrogen Sensor, Anne Guillory

Chemistry & Biochemistry Theses & Dissertations

The development of a potentiometric gaseous hydrogen sensor using a 75% palladium - 25% silver alloy as a selectively hydrogen permeable electrode is described. The sensor showed some promise when used with a molten base electrolyte. Other electrolytes are investigated at ambient and higher temperatures. Various cell designs including a platinum/silver-silver chloride sensor with a gel electrolyte are discussed.

Seasonal And Diel Patterns Of Abundance And Productivity Of Phototrophic Picoplankton In The Lower Chesapeake Bay, Lewis Francis Affronti Jr.

Biological Sciences Theses & Dissertations

This study was performed to evaluate phototrophic pico-plankton (0.2 to 2.0 μm) dynamics within the lower Chesapeake Bay. A 15 month study of phototrophic picoplankton abundance and productivity was made from June 1988 to October 1989. Annual picoplankton abundance using epifluorescence microscopy ranged from 7.26 x 10⁶ cells/1 in the winter to 9.28 x 10⁸ cells/1 during late summer.

In situ incubations of natural picoplankton populations over the 15 month study were used to test the applicability of the frequency of dividing cells technique in estimating phototrophic picoplankton growth rates. The regression equation o fμ = 2.37 x …

Navier-Stokes Simulations Of Flows About Complex Configurations Using Domain Decomposition Techniques, Kamran Fouladi-Semnani

Mechanical & Aerospace Engineering Theses & Dissertations

An algorithm is developed to obtain numerical simulations of flows about complex configurations composed of multiple and nonsimilar components with arbitrary geometries. The algorithm uses a hybridization of the domain decomposition techniques for grid generation and to reduce the computer memory requirement. Three dimensional, Reynolds-averaged, unsteady, compressible, and complete Navier-Stokes equations are solved on each of the subdomains by a fully-vectorized, finite-volume, upwind-biased, approximately-factored, and multigrid method. The effect of Reynolds stresses is incorporated through an algebraic turbulence model with several modifications for interference flows. The present algorithm combines the advantages of an efficient, geometrically conservative, minimally and automatically dissipative …

The Determination Of Clomiphene Citrate And Tamoxifen In Human Blood Plasma And Semen, Janice Irene Kiss

Chemistry & Biochemistry Theses & Dissertations

Triphenylethylene antiestrogen compounds are used to stimulate ovulation in anovulary women and spermatogenesis in oligozoospermatic males. Clomiphene Citrate (CC) is given therapeuticaly as a mixture of the trans (E) and cis (Z) isomers. Each of these isomers has its own characteristic agonist-antagonist profiles. Only the trans form of Tamoxifen (T) is administered therapeutically.

HPLC methodologies were developed for the determination of CC and Tin human blood and seminal plasma. The methodologies involved extraction of the triphenylethylene compounds using hexane, followed by evaporation of the hexane under N₂. The residue was then taken up in a volume of HPLC …

Metal Mobilization From A Near-Shore Lake Sediment Under Simulated Acidic Groundwater Inputs, Raveendra V. Ika

OES Theses and Dissertations

Simulation of acidic groundwater passing through lake sediments was conducted under controlled conditions in a laboratory. Three sediment cores collected intact from the near-shore region of an acidic lake were subjected to simulated groundwater inputs of initially identical chemistry for a seven day period. Following this period water being used in the simulation for two of the sediment cores was acidified by hydrochloric acid (HC1) addition to examine the ability of these sediments to neutralize acidic groundwater with varying H⁺ concentration.

Simulated acidic water passing through the sediment cores mobilized significant amounts of metals. The sediment acted as a …

Visual Speech Training Aid For The Deaf, Subhashri Venkat

Electrical & Computer Engineering Theses & Dissertations

A computer-based vowel articulation training aid has been developed. A "continuous" acoustic-phonetic transformation is performed to map speech parameters to a lower dimensionality display space. There are two possible approaches to this transformation problem. The transformation could be either linear or a combination nonlinear/linear. The nonlinear transformation is performed using a multi-layered feedforward neural network with linear output layers. Speech parameters are extracted either from an analog filter bank arrangement (band energies) or by a digital signal processing procedure (Discrete Cosine Transform Coefficients). The speech parameters obtained from both methods correspond to the spectral envelope of the speech signals. The …

Validation Of The Human Factors Satisfaction Questionnaire, James Carlopio

Psychology Theses & Dissertations

In order to predict behavior in organizations, it is important to understand and to consider both the individual employee and his/her interaction with the physical work environment. The main purpose of this research was to gather evidence of the validity of the Human Factors Satisfaction Questionnaire (HFSQ) in order to provide a tool with which employees' preceptions of several elements of their physical work environments can be measured. The physical work environment and its relationship to both organization theory and motivation theory is discussed. Evidence of the construct validity of the HFSQ was sought through the administration of the HFSQ …

Hemispheric Effects Of Verbal Information Processing On Single And Dual Task Performance, Gwendolyn Lorell Pearson

Psychology Theses & Dissertations

Several theories have been proposed to predict performance when operators time share tasks. The Hemispheres as Resources Model suggests tasks will be performed efficiently together if each hemisphere allocates resources to one task. The Task Hemispheric Integrity Principle predicts the best dual task performance will be found when the shortest processing route is maintained. The purpose of the present study was to test the single and dual task performance predictions of these two models. The concurrent performance of two verbal tasks was used to compare the importance of ear of attention, hemisphere of processing, response hand and gender on task …

Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal

Biological Sciences Theses & Dissertations

The effects of aneuploidogens (aneuploidy causing agents) on taxol-purified microtubules from Drosophila and mouse brain in vitro were studied by using a spectrophotometric assay and electron microscopy. Colchicine, acetonitrile, propionitrile, acrylonitrile, dimethyl sulfoxide (DMSO), griseofulvin and cadmium chloride inhibited microtubule polymerization whereas methoxyethyl acetate (MEA) and methyl mercuric chloride (MMC) did not. All aneuploidogens tested (at 50mM) resulted in reduced rate of elongation of mouse brain microtubules. MMC, cadmium chloride and DMSO resulted in increased rates of Drosophila microtubule elongation whereas the rest of the drugs resulted in decreases. The in vitro results from Drosophila correlate well with the previously …

A Numerical Study Of The Interaction Between A Deep Cold Jet And The Bottom Boundary Layer Of The Ocean, Tal Ezer, Georges L. Weatherly

CCPO Publications

Abstract A two-dimensional (x-z) primitive equation model is used to study the interaction between a deep cold jet on a sloping bottom and the bottom boundary layer (BBL) of the deep ocean. Two closure schemes are used: a standard second order turbulence closure (SOTC) scheme (the level 2 1/2 model of Mellor and Yamada), and a new eddy viscosity closure scheme (K-model). The latter is a computationally simple model that produces very similar eddy viscosity and velocity fields as the more complicated SOTC-model while saving about 20% of the computational time. The results of the numerical simulations compare favorably to …

Health Locus Of Control, Sexual Self-Concept, Self-Efficacy And The Contraceptive Behavior Of College Students, Lorraine Kime Perkins

Ellmer School of Nursing Theses & Dissertations

The purpose of the following study was to determine whether contraceptive use could be predicted from health locus of control, contraceptive self-efficacy, and sexual self-concept scores in a selected group of single college students ages 18-24. In order to better understand contraceptive behaviors, it is desirable to determine which personality variables may influence contraceptive behavior in young adults. A sample of 122 single undergraduate college students, both male and female, ages 18-24, completed a self-reported questionnaire including tools to measure health locus of control, contraceptive self-efficacy, and sexual self-concept, as well as demographic data. The participants were divided into two …

Head Nurse Leadership Behavior And Head Nurse And Staff Nurse Job Satisfaction And Burnout In The Intensive Care Setting, Dianne Vick Benton

Ellmer School of Nursing Theses & Dissertations

The purpose of this study was to examine the relationship between head nurse (HN) leadership behavior and head nurse and staff nurse (SN) job satisfaction and burnout in the Intensive Care Unit (ICU). The two target populations for this study were: ICU HNs and ICU SNs. A sample of 10 HNs and 65 SNs completed four questionnaires. This study was conducted in eight community hospitals ranging in bed size between 150 to 700. Four research questions were tested. Utilizing t-tests. a significant difference was found between ICU HNs' and SNs' perceptions of the HN leader behavior of high task - …

A Root Finding Algorithm For Parallel Architecture Machines, Stuti Moitra

Computer Science Theses & Dissertations

In this thesis a parallel algorithm for determining the zeros of any given analytic function is described. Parallelism is achieved by modifying the traditional bisection algorithm for architecture machines.

Given any user supplied function f(X), continuous on the interval A_o ≤ x ≤ B₀, and the tolerance of accuracy an algorithm of determining up to ten roots, with error of approximation less than or equal to tolerance, on parallel systems like Distributed Array Processor (OAP) and N-cube is considered.

A variation of the bisection method has been adapted for this purpose. At each level of iteration a …

Job Satisfaction And Retention: Outcomes Since Implementation Of Three Scheduling Options, Katherine Marie Newnam

Ellmer School of Nursing Theses & Dissertations

The purpose of this descriptive study was to determine if flexible scheduling options influenced retention and job satisfaction of 109 full time registered staff nurses within a selected hospital setting. The Anticipated Turnover Model, developed by Hinshaw and Atwood (1984) provided the theoretical framework for the study. Perceived job satisfaction was measured by the Nursing Job Satisfaction Scale (Hinshaw & Atwood, 1984). The Anticipated Turnover Scale (Hinshaw & Atwood, 1984) measured the possibility of voluntary termination by sample respondents. The respondents were divided into three groups according to three schedule options: Group 1, 12 hour, weekend only (Baylor); Group 2, …

An Explanatory Study Of Maternal Stress And Coping With A Cystic Fibrosis Child, Leslie G. Potter

Ellmer School of Nursing Theses & Dissertations

The purpose of this study was to explore the concept of coping with a cystic fibrosis (CF) child and to define coping strategies from the perspective of the mother. The research design was based upon a phenomenological approach with analysis of transcribed, semi-structured interviews with mothers of CF children. A purposive sample of eight mothers with CF children were interviewed to explore the maternal CF experience. Each interview was tape recorded and followed up with a phone call to allow the mothers to add additional information, if so desired. Data analysis consisted of reviewing each typed, verbatim transcript to categorize …

Effects Of An Urban Alternative High School Dropout Prevention And Rehabilitation Program On The Attendance, Attitude And Academic Achievement Of At-Risk Students, Margaret Shearin Bell

Theses and Dissertations in Urban Services - Urban Education

The purpose of this study was to determine the effects of a dropout prevention program on at-risk high school students who returned to their home schools. The study was conducted in Newport News, Virginia at four high schools and an alternative school site, housing the dropout program. The subjects were divided into two independent treatment groups: Group One (N = 30) who participated in the program in the fall semester of 1988 and returned to their home schools in the spring semester of 1989, and Group Two (N = 21) who participated in the program in the spring semester of …

Stability Of A Viscoelastic Burgers Flow, D. Glenn Lasseigne, W. E. Olmstead

Mathematics & Statistics Faculty Publications

The system of equations proposed by Burgers to model turbulent flow in a channel is extended to include viscoelastic affects. The stability and bifurcation properties are examined in the neighborhood of the critical Reynolds number. For highly elastic fluids, the bifurcated state is periodic with a shift in frequency.

Relationships Between Early Mother-Infant Interaction And Later Patterns Of Attachment, Christine Oakes Work

Psychology Theses & Dissertations

This study investigates the relationships between initiative and responsive attachment behaviors exchanged between mothers and infants in a free play laboratory observation, and later pattern of attachment. Pearson product-moment correlations revealed significant intercorrelations between frequencies of the different attachment behaviors studied. Factor analysis revealed seven factors, three of which were predictive of attachment security through main or interaction effects. High frequencies of infant eye contact in response to maternal initiations significantly predicted later insecure attachment. Attachment security could also be predicted from frequency rates of infant-initiated proximity seeking and vocalization, and maternal responsive non-parallel body contact. When infant gender was …

Knowing God In William Blake: A Study To Find Meaning In His Work Through Plato, Swedenborg, And Mystical Tradition, David B. Gabel

Institute for the Humanities Theses

This project takes a look into the philosophical and theological sources found in the work of William Blake as they culminate in his epic poem Jerusalem. This study includes an examination of the philosophies of Plato and Emanuel Swedenborg, the mystical pathway, the Jewish mystical tradition known as Kabbalah, and finally an examination of the works of Blake himself. We work from a three-fold premise: 1) that mystical experience occurs, 2) that archetypes exist in the collective unconscious, and 3) that these archetypes can be known through intuition and mystical experience. The focus is on those elements which are characteristic …

The Role Of The Voltage Gradient In The Agarose Gel Electrophoresis Of Dna, David Wheeler

Theses and Dissertations in Biomedical Sciences

In Part I of this dissertation, empirical equations for predicting DNA mobility during agarose gel electrophoresis (AGE) from voltage gradient are developed from the data of McDonnel (36) for electrophoresis in a 1.6% agarose gel. These equations represented the data well for DNA between 2 and 10 kilobase pairs (KBp) in length. A computer program, called GELSIM, which incorporates these equations is described in Part II. GELSIM was designed to allow researchers to analyze electrophoresis data by predicting the effect on DNA migration of altering the voltage of electrophoresis. In this way, electrophoretic banding patterns produced using different voltages could …

A Case Study In The Development Of A Cost Reduction Methodology In The Public Sector, Ross Cooper Haines

Engineering Management & Systems Engineering Theses & Dissertations

Intense fiscal pressures have caused the Department of Defense (DoD) to explore new ways of reducing operating expenses. The primary technique used to achieve this objective is the use of competition - recently for maintenance requirements not previously subjected to competition. One such maintenance requirement is the periodic overhaul of one of the Navy's front line fighter aircraft - the F-14A Tomcat. This case study documents the cost reduction methodology developed by the DoD's incumbent overhaul facility in preparation for competition. The methodology discusses task time estimation, cost center structure, labor rate development and analysis, internal cost transfers as well …

Marketing Higher Education To Mexican-Americans: Identification Of Successful Marketing Strategies And Tactics, Cynthia Gale Coiner

Theses and Dissertations in Urban Services - Urban Education

In this study, a comprehensive set of successful marketing strategies and tactics for the recruitment of Mexican-Americans into four-year colleges and universities was identified. A taxonomy of findings ranging from very successful to not successful was developed. The methodology included focus groups conducted in Los Angeles, California and San Antonio, Texas to aid in the creation of survey instrument items. The resulting survey was mailed to admissions directors of four-year colleges and universities located in the six southwestern states of Arizona, California, Colorado, Nevada, New Mexico, and Texas.

The responses were analyzed by computing frequencies and crosstabulations. Subsequently, factor analysis …

Retirement And Re-Entry Decision-Making: A Faculty Perspective, Seth Zimmer

Psychology Theses & Dissertations

Universities are faced with an aging workforce and threatened with deficits in number and quality of replacements for retirees. New policies and programs affecting retirement and workforce re-entry are taking shape. This points to the need for research on the factors used by faculty members in the retirement decision-making process.

Faculty are somewhat unique in that their university roles and responsibilities often allow them to be professionally active simultaneously in other settings. The usual concept of retirement becomes somewhat blurred where faculty members are concerned.

The decision of when to retire and whether or not to re-enter the workforce must …

The Truncated Cauchy Distribution: Estimation Of Parameters And Application To Stock Returns, Paul G. Staneski

Mathematics & Statistics Theses & Dissertations

The problem addressed in this dissertation is the existence and estimation of the parameters of a truncated Cauchy distribution. It is known that when a number of distributions with infinite support are truncated to a finite interval that the maximum likelihood estimator of the scale parameter fails to exist with positive probability. In particular, necessary and sufficient conditions which give rise to instances of non-existence have been found for the exponential (Deemer and Votaw (1955)), gamma (Broeder (1955), Hegde and Dahiya (1989)), Weibull (Mittal and Dahiya (1989)) and normal distribution (Barndorff-Nielsen (1978), Mittal and Dahiya (1987), Hegde and Dahiya (1989)). …

Analysis And Development Of A Switched Capacitor Power Supply, John Richard Hackworth

Electrical & Computer Engineering Theses & Dissertations

The combination of a switched capacitor network and switching power supply techniques can result in a transformer less regulated DC power supply that is small, relatively simple, and efficient. In addition, the output of such a system could be operated over a wide range of common mode voltages. Multiple switched capacitor supplies could be stacked to achieve voltage multiplication.

Although the output of a system of this type is a continuous function, the internal operation must be analyzed in finite time elements. This numerical analysis will be shown in both a mathematical approach and a computer model.

Hydrogenation Effects On Trap Related Conduction In Diamond, Linwood Cleveland Watkins Iii

Electrical & Computer Engineering Theses & Dissertations

In this research work, the results of an experimental investigation on the electrical conduction mechanism in type Ιa and Ilb diamonds are presented. These results are compared with those of previous theoretical studies. The basic physical properties of diamond are discussed. Details of ohmic contact formation on diamond are presented.

The current-voltage characteristics revealed the presence of traps located below the Fermi level. The unfilled trap density was determined. The deep traps were further studied using spectroscopic photoconductivity measurements and the trap energy levels were determined.

The effects of hydrogenation on trap related conduction were studied subsequently. Hydrogenation was carried …

From Roman Britain To Norman England Continuity And Change - C. A. D. 284 - 1066, Gary Philip Priolo

History Theses & Dissertations

Prior to the Norman Conquest English Society was different in many ways. To understand these differences one must look at the various influences that over eight centuries combined to create Saxon England. This study examines how Saxon English society was created from the contributions of the Romans, Anglo-Saxons, church, and Vikings.

Contemporary authors such as Bede and Gildas, and supporting archeological evidence indicate that the invaders and Christian missionaries had a significant impact on the native population of medieval Britain. Evidence suggests that the Romano-Britons were either killed or put to flight by the Anglo-Saxon settlers, the church first converted …

The Relationship Between Occupational Choice And Perceptions Of Professional Nursing Functions And Characteristics, Ellis Quinn Youngkin

Theses and Dissertations in Urban Services - Urban Management

This study identifies the occupational interests and predominant vocational personality types of freshmen students (undeclared majors, nursing majors, and non-nursing majors), explores perceptions about selected professional nursing functions and characteristics among the students, and examines perceptual differences between groups (majors).

A non-experimental ex post facto design is used to analyze data from 312 students in a large urban university. Descriptive and inferential statistics are applied in data analysis. The following findings support the hypotheses: (1) Nursing continues to attract the traditional student who has Holland's Social vocational personality type as measured by the Self-Directed Search, although many Social types are …

Diagnostics Software For Concurrent Processing Computer Systems, Robert L. Jones Iii

Electrical & Computer Engineering Theses & Dissertations

Diagnostics software for analyzing ATAMM based concurrent processing systems is presented in this thesis. ATAMM (Algorithm to Architecture Mapping Model) is a new model developed by researchers at Old Dominion University and the NASA-Langley Research Center. ATAMM is capable of modeling the execution of large grain algorithms on distributed data flow architectures. Investigating a real or simulated ATAMM based system requires the aid of software tools. The software tool presented in this thesis can evaluate the behavior and performance of an ATAMM based system. The tool graphically portrays algorithm activities and processor activities. The tool's measurement capabilities indicate computing speed, …

Radiative Interactions In Laminar Duct Flows, Prakash A. Trivedi

Mechanical & Aerospace Engineering Theses & Dissertations

Analyses and numerical procedures are presented for infrared radiative energy transfer in gases when other modes of energy transfer occur simultaneously. Two types of geometries are considered, a Parallel Plate Duct and a Circular Duct. Fully developed laminar incompressible flows of absorbing-emitting species in black surfaced ducts are considered under the conditions of uniform wall heat flux. The participating species considered are OH, CO, CO₂, and H₂O. Nongray as well as gray formulations are developed for both geometries. Appropriate limiting solutions of the governing equations are obtained and conduction-radiation interaction parameters are evaluated. Tien and Lowder's …