Digital Commons Network^™

A Flow Cytometric Approach To Assessing The Environmental And Physiological Status Of Phytoplankton, Serge Demers, Kimberly Davis, Terry L. Cucci

CCPO Publications

No abstract provided.

Gender Differences In The Relation Between Locus Of Control And Physiological Responses, Monique C. Grelot

Psychology Theses & Dissertations

The relationship between locus of control and the physiological responses of heart rate (HR) and electrodermal activity (EDA) was investigated in 30 males and 31 females during an arithmetic task. The Levenson's Internal, Powerful Others and Chance (IPC) scales (Levenson, 1974) were used to assess the various degrees of internality for each subject. Additionally, to determine each subject's physiological Lability or Stability (LS), EDA was measured by recording spontaneous skin conductance responses during a ten minute rest period and to a tone (an Orienting Response (OR) task). A simple difficulty effect was found on the performance scores across the three …

Automatically Generating Functional Tests From Specifications - A Knowledge Based Constraint Logical Programming Approach, Ji Chen

Computer Science Theses & Dissertations

Recent experimental results indicate that functional testing is one of the most effective methods in detecting certain classes of faults. Very little work has been done in automating functional testing. This thesis research develops a method, called hierarchical partition, for automating functional testing. The key to our approach is the utilization of a pre-existing knowledge base about the domain of discourse. Several approaches to knowledge organiza­tion are discussed along with the resulting effects on the quantity and quality of functional tests produced. This research is an application and development of Generic Constraint Logic Programming and the Knowledge Driven …

Community Responses To Variable Predation: Field Studies With Sunfish And Freshwater Macroinvertebrates, Mark J. Butler Iv

Biological Sciences Faculty Publications

The impact of variable predation by bluegill sunfish on macroinvertebrate prey in a North Florida lake is examined. Variable predation may occur in many systems and may contribute substantially to the spatial heterogeneity, temporal inconstancy and species composition of prey communities.

Patchy, temporally variable predation characterized middepth and deep lake habitats, whereas in the shallow zone predation was relatively constant and homogeneous. Predation varied significantly every 2-4 wk in the mid-depth zone, but varied little between consecutive weeks or days. Caging experiments revealed that variable predation altered prey community composition and increased the mean size and size range of some …

A Study To Determine The Reading Ability Of Electronics Technology Students, Franklin Wayne Pond

OTS Master's Level Projects & Papers

The goals of this research study were as follows: 1. What is the average grade level of the students in electronics technology? 2. What is the average reading ability of electronics technology students? 3. What is the readability level of the approved textbooks for the courses?

Hydrographic Variability Of Southeastern United States Shelf And Slope Waters During The Genesis Of Atlantic Lows Experiment: Winter 1986, Larry P. Atkinson, Eiichi Oka, Sunny Y. Wu, Thomas J. Berger, Jackson O. Blanton, Thomas N. Lee

CCPO Publications

Continental shelf waters are particularly responsive to winter storm events mainly because of their shallow depths. Those of the southeastern United States (the South Atlantic Bight (SAB)) are especially responsive because they are broad and shallow. Also, the Gulf Stream serves as a continual source of warm water at the outer boundary. Thus the SAB receives strong meteorological (wind stress and heat loss) and oceanographic (advective) forcing. During the Genesis of Atlantic Lows Experiment (GALE) the response of shelf waters to winter storm events and Gulf Stream forcing was observed. The mean conditions showed a mixed water column with areas …

A Nonlinear Eigenvalue Problem In Astrophysical Magnetohydrodynamics: Some Properties Of The Spectrum, John A. Adam

Mathematics & Statistics Faculty Publications

The equations of ideal magnetohydrodynamics (MHD) with an external gravitational potential—a ‘‘magnetoatmosphere’’—are examined in detail as a singular nonlinear eigenvalue problem. Properties of the spectrum are discussed with specific emphasis on two systems relevant to solar magnetohydrodynamics. In the absence of a gravitational potential, the system reduces to that of importance in MHD and plasma physics, albeit in a different geometry. This further reduces to a form isomorphic to that derived in the study of plasma oscillations in a cold plasma, Alfvén wave propagation in an inhomogeneous medium, and MHD waves in a sheet pinch. In cylindrical geometry, the relevant …

Assessing Soccer Referee Performance Using Work Sample And Conventional Testing Methods, Robert L. Kuhnle

Psychology Theses & Dissertations

A game simulation consisting of game segments filmed from two camera angles, a behavioral event interview (BEI), a written test, and a physical performance test battery were compared for testing college soccer referees as linesmen. A content-oriented strategy (Alba & Dickinson, 1985) was used to prepare the tests. Sixty-one referees from two testing sites were assigned to one of two conditions of physical demand and one of three experience groups. Strong evidence of criterion-related validity was found for the game simulation from the press box camera angle when game simulation scores were compared with peer ratings and assessment scores. Mixed …

On Vector Sequence Transforms And Acceleration Techniques, Steven L. Hodge

Mathematics & Statistics Theses & Dissertations

This dissertation is devoted to the acceleration of convergence of vector sequences. This means to produce a replacement sequence from the original sequence with higher rate of convergence.

It is assumed that the sequence is generated from a linear matrix iteration x_i+ i = Gx_i + k where G is an n x n square matrix and x_I+1 , x_i,and k are n x 1 vectors. Acceleration of convergence is obtained when we are able to resolve approximations to low dimension invariant subspaces of G which contain large components of the error. When …

Effects Of Nose Bluntness And Shock-Shock Interactions On Blunt Bodies In Viscous Hypersonic Flows, Dal J. Singh

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical study has been conducted to investigate the effects of blunt leading edges on the viscous flow field around a hypersonic vehicle such as the proposed National Aero-Space Plane. Attention is focused on two specific regions of the flow field. Analysis of these flow regions is required to accurately predict the overall flow field as well as to get necessary information on localized zones of high pressure and intense heating.

The forebody is modeled by slender cones and ogives with spherically blunted nose. A combination of Navier-Stokes and parabolized Navier-Stokes equations is used to compute the flow field. The …

Laureate, 1989, Old Dominion University

University Yearbooks

1989 yearbook of Old Dominion University

Optical Recording Aspects Of Rf Magnetron Sputtered Iron-Garnet Films, J.P. Krumme, V. Doormann, P. Hansen, H. Baumgart, J. Petruzzello, M.P.A. Viegers

Electrical & Computer Engineering Faculty Publications

The intrinsic magneto-optical readout performance in reflection is calculated for bismuth and cobalt-substituted iron-garnet films on a multilayer interference mirror at 800-, 633-, 488-, and 420-nm wavelengths and is compared with that of a trilayer medium composed of an antireflection layer, a rare-earth transition-metal film, and a metallic mirror. It is found, when disregarding inhomogeneities, like irregular domain shape, ripple of the magnetic anisotropy, and surface roughness, that iron garnets are superior to rare-earth transition-metal films at blue to near-ultraviolet wavelengths if operated at thicknesses where optical interference occurs in the magnetic layer. Optical transmittance at these thicknesses is sufficiently …

Nanosecond Optical Quenching Of Photoconductivity In A Bulk Gaas Switch, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, S. T. Ko

Electrical & Computer Engineering Faculty Publications

Persistent photoconductivity in copper-compensated, silicon-doped semi-insulating gallium arsenide with a time constant as large as 30 µs has been excited by sub-band-gap laser radiation of photon energy greater than 1 eV. This photoconductivity has been quenched on a nanosecond time scale by laser radiation of photon energy less than 1 eV. The proven ability to turn the switch conductance on and off on command, and to scale the switch to high power could make this semiconductor material the basis of an optically controlled pulsed-power closing and opening switch.

Phytoplankton Composition In A Borrow Pit Lake In Virginia, Seba B. Sheavly, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton assemblages in Lake Trashmore, Virginia, a borrow pit, were dominated by centric diatoms and cyanobacteria, with seasonal pulses of cryptomonads, euglenoids, and chlorophyceans. Ninety species were identified and their abundance levels noted for a 12-month period.

Are Artificial "Witham" Surface Collectors Adequate Indicators Of Caribbean Spiny Lobster, Panulirus Argus, Recruitment?, Mark J. Butler Iv, William F. Herrnkind

Biological Sciences Faculty Publications

Understanding the local dynamics of Caribbean spiny lobster (Panulirus argus) postlarval influx, settlement, and recruitment may be essential for the responsible management of this important and heavily exploited resource. Most lobster recruitment research programs in the Caribbean employ derivations of the "Witham"-type surface collector to monitor postlarval (puerulus) lobster influx. However, the relevance of data obtained from surface collectors with respect to the estimation of actual puerulus influx, settlement, or recruitment to subsequent benthic juvenile stages remains untested. We investigated that relevance on regional (i.e., tens of kilometers) and local (i.e., tens of meters) scales by examining the …

The Effect On Earth's Surface-Temperature From Variations In Rotations Rate, Continent Formation, Solar Luminosity, And Carbon Dioxide, William R. Kuhn, J. C.G. Walker, Harold G. Marshall

Biological Sciences Faculty Publications

Proposed evolutionary histories of solar luminosity, atmospheric carbon dioxide amounts, Earth rotation rate, and continent formation have been used to generate a time evolution of Earth's surface temperature. While speculative because of uncertainties in the input parameters, such a study does help to prioritize the areas of most concern to paleoclimatic research while illustrating the relationships and mutual dependencies. The mean temperature averages about 5 K higher than today over most of geologic time; the overall variation is less than 15 K. The evolution of Earth's rotation rate makes a significant contribution to the surface temperature distribution as late as …

Gaas Photoconductive Closing Switches With High Dark Resistance And Microsecond Conductivity Decay, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, R. Germer, G. M. Loubriel, F. J. Zutavern

Electrical & Computer Engineering Faculty Publications

Silicon-doped n-type gallium arsenide crystals, compensated with diffused copper, were studied with respect to their application as photoconductive, high-power closing switches. The attractive features of GaAs:Cu switches are their high dark resistivity, their efficient activation with Nd:YAG laser radiation, and their microsecond conductivity decay time constant. In the authors' experiment, electric fields are high as 19 kV/cm were switched, and current densities of up to 10 kA/cm² were conducted through a closely compensated crystal. At field strengths greater than approximately 10 kV/cm, a voltage `lock-on' effect was observed.

Patients' Perceived Benefits Of Home Health Services, Rita M. Holley

Community & Environmental Health Theses & Dissertations

Home care can be described as the provision of health and related social support services to physically and mentally impaired persons in the places of residence considered to be their homes. The purpose of the study was to examine the patients' self perceived benefits of home health care services delivered in Chesapeake, Virginia. This investigation sought to study client satisfaction as it applies to area specific delivery of services, professional competence, and personal qualities. The target population were residents of Chesapeake, Virginia, who were currently or had recently received home care services from ComfortCare Home Health Services.

Sulfide In Surface Waters Of The Western Atlantic Ocean, Gregory A. Cutter, Christian F. Krahforst

OES Faculty Publications

Using newly developed techniques, some preliminary data on hydrogen sulfide in surface waters of the western Atlantic have been obtained. Concentrations of total sulfide range from <0.1 to 1.1 nmol/L, and vary on a diel basis. At these concentrations, sulfide may affect the cycling of several trace metals via the formation of stable complexes. Production of sulfide in oxygenated seawater may occur through the hydrolysis of carbonyl sulfide or by sulfate reduction within macroscopic particles in the water column. Removal mechanisms can include oxidation, complexation with particulate trace metals, and metal sulfide precipitation. However, the temporal and spatial distributions suggest a complex set of processes governing the behavior of sulfide in the surface ocean.

The Synthesis And Evaluation Of 5-Phenyloxazolidines As Potential Cardiovascular Drugs, Tammy C. Wang

Chemistry & Biochemistry Theses & Dissertations

Drugs such as adrenoceptor antagonists and certain centrally acting agents are known to lower blood pressure and thus serve as clinically useful antihypertensive agents. Norepinephrine 4, a natural ∝-adrenoceptor agonist, is the major agent associated with increased blood pressure in the periphery. Based on a careful structure-activity comparison, a series of substituted oxazolidines, 20, 21, 22 and 23, have been designed as possible antihypertensive candidates. Specifically, 22 and 23 have been synthesized to serve as potential norepinephrine antagonists.

Preliminary evaluation of these compounds indicated that they were not antihypertensive in nature. The more active compound, 23, …

Structural Geology Of Page Valley, Page County, Virginia, Tamera J. Warden

OES Theses and Dissertations

Page Valley contains folded and faulted Cambro-Ordovician rocks that were deformed during the Pennsylvanian-Permian Alleghanian Orogeny. Previous authors (Allen, 1967; Thornton, 1953; and King, 1950) have mapped "high-angle" faults and a klippe along the South Fork of the Shenandoah River west of Luray, Virginia. The southernmost fault offsets the New Market/Lincolnshire and Edinburg formations with the upthrown block to the west. Thornton suggested gravity sliding and strike-slip movement to explain normal displacements along the northernmost fault where the Edinburg Formation is in contact with overturned beds of the Beekmantown Formation. A klippe, as mapped by Allen and Thornton, lies on …

Optimization Of The Tungstic Acid Denuder Technique For The Measurement Of Atmospheric Ammonia, Patricia Diane Roberts

Chemistry & Biochemistry Theses & Dissertations

Measurement of - atmospheric ammonia with the tungstic acid denuder technique is discussed. Characterization of denuder tubes for manual sampling in terms of, repeatability, reliability and the development of ammonia blank signals was determined. Field testing of the manual sampling apparatus was performed at ground test sites and in a biomass burn smoke plume. Ammonia emissions from biomass burning are discussed.

Vertical Distribution Of Phytoplankton Populations Along The Northeastern Continental Shelf Margin Of The United States, Bruce Burwell Wagoner

Biological Sciences Theses & Dissertations

A study of phytoplankton vertical distribution at six stations along the northeast continental shelf of the United States was conducted in April 1984.

A total of 168 taxa were identified from nine phylogenetic groups collected at depths up to 150 m. Highest cell concentrations and cell volumes were in the upper 30 m. Greatest cell concentrations were produced by diatoms and a pico-nanoplankton component, with cell volumes mainly the product of diatoms and dinoflagellates. A high degree of variability was observed between phylogenetic groups within each station, but less variability was noted for phylogenetic categories at different stations.

Little difference …

Nutrient Cycling In Bordenstake Bay Sediments: A Backbarrier Lagoon, Mark J. Herrenkohl

OES Theses and Dissertations

Six sets of sediment cores were collected over a one year period (June 1986 to July 1987) to examine nutrient cycling in Bordenstake Bay, a back barrier lagoon on Virginia's Eastern Shore Peninsula. The sampling times were chosen to examine any seasonal effects (e.g., temperature changes) which may affect the rates of metabolism in these sediments.

The sedimentation rate in Bordenstake Bay is 0.76 ± 0.21 cm/yr, leading to the annual deposition of 7. 05 moles of carbon, 0.46 moles of nitrogen, and 0.15 moles of phosphorus, per square meter of the sediment surface. The remineralization of organic matter in …

Reopening The Fair Gate, Toshihiro Tanioka

History Theses & Dissertations

On July 27, 1952, the Congress of the United States of America passed, over President Harry s. Truman's veto, the Immigration and Nationality Act of 1952, more commonly known as the McCarran-Walter Act. The act codified almost all existing laws relative to immigration and naturalization and newly incorporated more strict exclusion provisions.

This paper analyzes the legislative process from the passage of the act in 1952 to its major revision in 1965. The paper analyzes that the act was a mere reaffirmation of the pre-war immigration policy and thus not reappraisal or reformation in the drastically changed world milieu. The …

An Arrayed Hot-Film Sensor For Detection Of Laminar Boundary-Layer Flow Disturbance Spatial Characteristics, Michael S. Wusk

Mechanical & Aerospace Engineering Theses & Dissertations

An arrayed hot-film sensor has been developed for use in laminar boundary-layer research for the detection of crossflow or Gortler vortices. This sensor has been developed to detect spatial variations in heat transfer and velocity perturbations which are characteristic of crossflow or Gortler vortices. The sensor is ultimately intended for flight research applications. This thesis describes the sensor, its principles of operation, signal analysis techniques, and experimental results illustrating the spatial detection capabilities of this specialized hot-film device. Discretely placed spheres placed in the boundary layer created alternating regions of undisturbed and disturbed laminar flow over a prototype sensor. Flow …

Recent Benthic Foraminifera Of Breton And Stake Islands Northern Gulf Of Mexico, Eric S. Collins

OES Theses and Dissertations

Fifty-three species of recent benthic foraminifera and thecamoebians have been documented and described from the Breton and Stake Island area, northern Gulf of Mexico, and from a core from Barataria Basin, Mississippi delta.

Cluster analysis of benthic assemblages using presence/absence and transformed abundance data reveals the presence of a marsh and shallow water marine biofacies. Based on the results of a presence/absence cluster analysis, the shallow water marine biofacies can be subdivided into a miliolid biofacies am an Ammonia beccarii/Elphidium species biofacies. Cluster analysis of transformed abundance data, however, shows that the shallow marine biofacies can be subdivided into four …

Interactions Between Aquatic Chromogenic Bacteria And Pathogenic Vibrio Spp., John Louis Harris

Biological Sciences Theses & Dissertations

Interactions between populations inhabiting an ecosys­tem are responsible, in large part, for determining which species coexist in that ecosystem. In this study, interac­tions between selected Vibrio species, V. alginolyticus and V. anguillarum, and marine heterotrophic, chromogenic bac­teria in aquatic microcosms were investigated. The ultimate goal of this project was to evaluate the feasibility of ex­ ploiting competitive interactions as a means to biologically control growth of the pathogenic marine bacteria, V. alginolyticus and V. anguillarum. In the majority of ex­periments (14/16), if chromogenic species were allowed to develop stable populations before a Vibrio spp. was intro­duced into a …

Distribution Of Suspended Particulate Matter, Patuxent River Estuary, Maryland, Christopher W. Frye

OES Theses and Dissertations

Physical processes which may affect estuarine circulation in a coastal plain estuary were monitored to determine their relative importance on temporal and spatial variability of the concentration, composition, and particle-size of suspended particulate matter (SPM) in Patuxent River estuary, MD, during 1985-86. Discharge rates from Patuxent River determined the character of fresh and estuarine water mixing, and magnitude of SPM concentration in the upper estuary. The mixing zone between fresh and estuarine water, defined as 0 - 1.5 °‰, and turbidity maximum were geographically separated during most of the study period. This suggests that two-layer circulation may be less important …

Trace Elements In Northern Virginia Middle Ordovician Carbonates: Implications For Diagenesis, Ruth Ann Strauss

OES Theses and Dissertations

Ninety-three carbonate rock samples collected from four of the major lithofacies types present in the Middle Ordovician limestone sequence of northwestern Virginia were analyzed to investigate whether the lithofacies bear the geochemical signature of the depositional and/or the diagenetic environment. Significant variations in Cr, Fe, Mg, Mn and Sr concentrations exist among the major lithofacies types. Low levels of Sr in both New Market lithofacies are indicative of an open system during diagenesis. Dissimilar Fe and Mn concentrations between these, however, reflect water chemistry differences in the depositional environment. Increasingly greater Cr, Fe, Mn, and Sr concentrations in the Lincolnshire …