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Articles 31 - 60 of 152
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Growth Dynamics Of A York River Estuary Heterotrophic Dinoflagellate Grazing Katodinium Rotundatum, Angela Denise Smith
Growth Dynamics Of A York River Estuary Heterotrophic Dinoflagellate Grazing Katodinium Rotundatum, Angela Denise Smith
Dissertations, Theses, and Masters Projects
No abstract provided.
Phylogeny Of The Haplosporidia (Eukaryota: Alveolata) Based On Small Subunit Ribosomal Rna Gene Sequence, Brenda Sandy Flores
Phylogeny Of The Haplosporidia (Eukaryota: Alveolata) Based On Small Subunit Ribosomal Rna Gene Sequence, Brenda Sandy Flores
Dissertations, Theses, and Masters Projects
No abstract provided.
Potential For Population Regulation Of The Zebra Mussel, Dreissena Polymorpha, In The Hudson River, Larry C. Boles
Potential For Population Regulation Of The Zebra Mussel, Dreissena Polymorpha, In The Hudson River, Larry C. Boles
Dissertations, Theses, and Masters Projects
No abstract provided.
An Analysis Of The Effects Of Sea Level Rise On The Salt Marshes Of Cape Hatteras National Seashore, North Carolina, Christopher Robert Perle
An Analysis Of The Effects Of Sea Level Rise On The Salt Marshes Of Cape Hatteras National Seashore, North Carolina, Christopher Robert Perle
Dissertations, Theses, and Masters Projects
No abstract provided.
A Bipartite Model Of Distributed Systems: Possibilities And Implications, Anna Karin Brunstrom
A Bipartite Model Of Distributed Systems: Possibilities And Implications, Anna Karin Brunstrom
Dissertations, Theses, and Masters Projects
Networking software is generally designed in layers. User processes exist at the application layer. They rely on the transport layer to provide them with end-to-end communication. In the distributed systems literature communication is traditionally viewed from the application layer. at the application layer we have no knowledge of the whereabouts of a message once a send operation is completed. at the transport layer, on the other hand, information about the delivery of a message to the transport layer in the receiving host is often available. We believe transport layer information can be better utilized in distributed systems design. This dissertation …
Synthesis And Characterization Of Boron-Containing Polymeric Materials For Neutron Shielding Applications, Michael B. Glasgow
Synthesis And Characterization Of Boron-Containing Polymeric Materials For Neutron Shielding Applications, Michael B. Glasgow
Dissertations, Theses, and Masters Projects
The development of boron-containing polymeric materials for neutron shielding applications was undertaken. Three types of materials were characterized for physical and thermal properties: boron powder-filled epoxy composites, carborane polyamides having boron chemically bonded into the polymer, and boron-loaded polyimide thin films. Addition of amorphous submicron boron powder did not affect significantly the thermal performance of the epoxy. The 17% boron loading produced a 26% increase in compressive failure strength and a 68% increase in the compressive modulus. 0.125 inch thick specimens containing 17% boron absorbed 92% of incident neutrons from a 5-Curie Pu/Be source compared with {dollar}<{dollar}1% for the neat epoxy. Dispersion of the boron in the epoxy was improved with the addition of larger size crystalline boron powders. Carborane polyamides containing up to 35% boron were thermally stable up to 400{dollar}\sp\circ{dollar}C in air. The polymers had hydrogen/boron ratios from 2.0 to 3.8 and were soluble in several organic solvents. Polymer solutions were processed into clear, colored thin films. Boron-filled polyamic acid solutions of a PMDA-ODA polyimide containing up to 10% boron were processed into thin films. Neutron absorption of the opaque films measured in a 5-Curie Pu/Be neutron source was linear with boron concentration and film thickness. The fraction of neutrons absorbed varied linearly with boron concentration and film thickness. The applicability of boron-containing materials to the aerospace, nuclear power and accelerator industries was investigated.
Ship Of Wealth: Massachusetts Merchants, Foreign Goods, And The Transformation Of Anglo-America, 1670-1760, Phyllis Whitman Hunter
Ship Of Wealth: Massachusetts Merchants, Foreign Goods, And The Transformation Of Anglo-America, 1670-1760, Phyllis Whitman Hunter
Dissertations, Theses, and Masters Projects
This study examines capitalism and cultural change in early New England. The research focuses on leading merchants in Boston and Salem, Massachusetts from the last third of the seventeenth century to 1760. During this period, merchants, royal officials, and professionals formed a prominent influential elite that refashioned the town landscape and social structure of colonial ports. Merchants adopted a new Anglo-American worldview that gradually supplanted Puritan spiritual and providential understanding of the world and, instead, emphasized visible, material characteristics as the source of value in science, commerce, and consumption. The resultant "world of goods," created a social marketplace where identity, …
Structured Eigenvectors, Interlacing, And Matrix Completions, Brenda K. Kroschel
Structured Eigenvectors, Interlacing, And Matrix Completions, Brenda K. Kroschel
Dissertations, Theses, and Masters Projects
This dissertation presents results from three areas of applicable matrix analysis: structured eigenvectors, interlacing, and matrix completion problems. Although these are distinct topics, the structured eigenvector results provide connections.;It is a straightforward matrix calculation that if {dollar}\lambda{dollar} is an eigenvalue of A, x an associated structured eigenvector and {dollar}\alpha{dollar} the set of positions in which x has nonzero entries, then {dollar}\lambda{dollar} is also an eigenvalue of the submatrix of A that lies in the rows and columns indexed by {dollar}\alpha{dollar}. We present a converse to this statement and apply the results to interlacing and to matrix completion problems. Several corollaries …
Analysis Of (Iso)Surface Reconstructions: Quantitative Metrics And Methods, Tracey Allen Beauchat
Analysis Of (Iso)Surface Reconstructions: Quantitative Metrics And Methods, Tracey Allen Beauchat
Dissertations, Theses, and Masters Projects
Due to sampling processes volumetric data is inherently discrete and most often knowledge of the underlying continuous model is not available. Surface rendering techniques attempt to reconstruct the continuous model, using isosurfaces, from the discrete data. Therefore, it natural to ask how accurate the reconstructed isosurfaces are with respect to the underlying continuous model. A reconstructed isosurface may look impressive when rendered ("photorealism"), but how well does it reflect reality ("physical realism")?;The users of volume visualization packages must be aware of the short-comings of the algorithms used to produce the images so that they may properly interpret, and interact with, …
The Projector Basis Method For Electronic Band Structure Calculations, Christopher Haas
The Projector Basis Method For Electronic Band Structure Calculations, Christopher Haas
Dissertations, Theses, and Masters Projects
Over the last several decades, two methods have emerged as the standard tools for the calculation of electronic band structures. These methods, the Car-Parinello plane wave method and the linear augmented plane wave method (LAPW), each have strengths and weaknesses in different regimes of physical problems. The Car-Parinello algorithm is ideal for calculations with soft pseudopotentials and large numbers of atoms. The LAPW method, on the other hand, easily handles all-electron and hard-core pseudopotential calculations with a small number of atoms. The projector basis method, presented here, is a hybrid mixed basis method which allows the calculation of moderately large …
The Strong Force: Two Calculations Of Strong Interaction Phenomena, Richard L. Kahler
The Strong Force: Two Calculations Of Strong Interaction Phenomena, Richard L. Kahler
Dissertations, Theses, and Masters Projects
Because the theory of strong interactions is mathematically intractable, it is necessary to make approximations which preserve phenomenological features of the theory in order to get answers to practical questions. This thesis explores two such techniques: (1) the chiral bag model is used to investigate the nucleon-nucleon potential and (2) perturbative QCD is used to investigate the pion form factor. An extensive introduction is presented to make the thesis more understandable to a wider audience of people otherwise unfamiliar with particle physics.
Propagation Of Guided Acoustic Waves In Composite Media, Michael David Seale
Propagation Of Guided Acoustic Waves In Composite Media, Michael David Seale
Dissertations, Theses, and Masters Projects
Composite materials are being more widely used today by aerospace, automotive, and a number of other commercial industries because of their advantages over conventional metals. Composites are finding applications ranging from bicycle frames to the proposed High-Speed Civil Transport (HSCT). Determining the response to a variety of damage mechanisms is necessary for a complete understanding of the total use environment of composite structures. The objective of the research presented here is to provide a method of quantifying the amount of damage in composite materials for a number of different damage scenarios. Components which have non-visible damage, but have degraded performance, …
Surface Reflection Hyperthermal Neutral Stream Source, Christopher A. Nichols
Surface Reflection Hyperthermal Neutral Stream Source, Christopher A. Nichols
Dissertations, Theses, and Masters Projects
A novel source of hyperthermal (1-30 eV) reactive neutrals based on the surface-reflection-neutralization technique is described. This source is potentially capable of minimizing the charge-induced damage associated with plasma based semiconductor processing steps. The goal of this thesis is to investigate the issues involved in scale-up of this technology for processing of 8{dollar}\sp{lcub}\prime\prime{rcub}{dollar} diameter wafers used today in the semiconductor industry. This includes modeling the plasma ion source and trajectory simulations of the reflected neutral flux. A prototype source was constructed for experimental verification of the plasma model.;An inductively coupled plasma (ICP) source is used to provide a source of …
"Preserving Their Form And Features": The Role Of Coffins In The American Understanding Of Death, 1607-1870, Brent Warren Tharp
"Preserving Their Form And Features": The Role Of Coffins In The American Understanding Of Death, 1607-1870, Brent Warren Tharp
Dissertations, Theses, and Masters Projects
This dissertation is a study of the American coffin, its origins, forms, and meanings especially with regard to its role in the integration of death in American society before 1870. Coffins have generally been ignored by material culture studies primarily because of our society's cultural uneasiness with the topic of death. Current American funeral and burial practices seem bizarre and ahistorical and have often been characterized as the result of twentieth-century commercial greed. However, coffins have a long history as important artifacts which American society has used to legitimize death in subtly different ways for generations. This study examines the …
First Measurement Of The Induced Proton Polarization, P(N), In The C-12 (E, E'P) Reaction, Rhett J. Woo
First Measurement Of The Induced Proton Polarization, P(N), In The C-12 (E, E'P) Reaction, Rhett J. Woo
Dissertations, Theses, and Masters Projects
The induced proton polarization, {dollar}P\sb{lcub}n{rcub},{dollar} was measured with the newly commissioned Recoil-Proton Focal Plane Polarimeter (FPP) at the MIT-Bates Linear Accelerator Laboratory. Using the {dollar}\sp{lcub}12{rcub}{lcub}\rm C{rcub}(e,e\sp\prime\vec p){dollar} reaction, the measurement was performed in quasifree kinematics at a {dollar}Q\sp2{dollar} of 0.48 (GeV/c){dollar}\sp2.{dollar} A recoil-momentum range of 0-250 MeV/c was sampled. The induced polarization, which vanishes in the Plane Wave Impulse Approximation, is sensitive to the absorptive part of the central optical-potential as well as explicit spin dependent terms, especially those due to spin-orbit interactions. Theoretical analysis indicates that this observable is primarily sensitive to final state interactions. For the experiment, the …
Facing Philadelphia: The Social Functions Of Silhouettes, Miniatures, And Daguerreotypes, 1760-1860, Anne Ayer Verplanck
Facing Philadelphia: The Social Functions Of Silhouettes, Miniatures, And Daguerreotypes, 1760-1860, Anne Ayer Verplanck
Dissertations, Theses, and Masters Projects
In 1807, Charles Fraser lauded fellow miniature artist Edward Greene Malbone's ability to produce "such striking resemblances, that they will never fail to perpetuate the tenderness of friendship, to divert the cares of absence, and to aid affection in dwelling on those features and that image which death has forever wrested from it." The explanations traditionally given for the commissioning of portraits--the perpetuation of family or institutional memory--correspond with Fraser's comments. Yet these explanations rarely incorporate the social context: the communities in which images were produced and the individual, familial, or group meanings of portraits.;"Facing Philadelphia: The Social Functions of …
Electroweak Interactions And Exchange Currents In Nuclei, Sergei M. Ananyan
Electroweak Interactions And Exchange Currents In Nuclei, Sergei M. Ananyan
Dissertations, Theses, and Masters Projects
In the first part of the dissertation, a consistent model for the long-range part of the weak meson exchange currents (MEC) preserving basic symmetries of the strong interactions is developed within the framework of an hadronic field theory of nuclear structure (QHD). A model which builds the nucleon-nucleon interaction out of {dollar}\sigma,\ \omega{dollar} and {dollar}\pi{dollar} meson exchange is used to describe strong interactions in a nucleus. The scalar-pseudoscalar part of the problem coincides with the {dollar}\sigma{dollar}-model. In the linear realization of the sigma-model one obtains spatial axial exchange currents of order (1/M) in a non-relativistic decomposition in nucleon mass due …
Selective Inversion In Solid-State Deuteron Nmr, Marco J. Brown
Selective Inversion In Solid-State Deuteron Nmr, Marco J. Brown
Dissertations, Theses, and Masters Projects
Deuteron NMR selective inversion (SI) is developed to study slow molecular motions in solids. Theoretical and practical aspects of selective inversion of spin-1 nuclei in solids are presented. Differences between powdered solids and liquids are considered. Double sideband modulated (DSBM) shaped pulses are shown to improve the performance of SI pulses. DSBM and DANTE selective pulses are compared for off-resonance SI applications. Common spin-{dollar}{lcub}1{rcub}\over{lcub}2{rcub}{dollar} shaped pulses are tested for suitability to solid state deuteron NMR. Simple, short pulses are shown to be most effective due to fast spin-spin relaxation and large underlying homogeneous linewidths in solids.;The power and utility of …
Expression Of The Xenobiotic Transporter P-Glycoprotein In The Mummichog (Fundulus Heteroclitus), Peter S. Cooper
Expression Of The Xenobiotic Transporter P-Glycoprotein In The Mummichog (Fundulus Heteroclitus), Peter S. Cooper
Dissertations, Theses, and Masters Projects
The mammalian mdr1 P-glycoprotein (Pgp) has been implicated in xenobiotic resistance of drug-resistant cell lines and tumors, and may function in excretion or exclusion of toxic xenobiotics at several sites within the body. Pgp gene family members are expressed in excretory epithelia of several aquatic taxa and may contribute to the survival of pollution-tolerant aquatic animals in contaminated environments. For this reason the expression of Pgp family members was investigated in the livers and liver tumors of creosote-resistant mummichog (Fundulus heteroclitus) inhabiting a creosote-contaminated site (Atlantic Wood) in the Elizabeth River, Virginia. Expression of members of the Pgp gene family …
Contributions To The Life History Of Juvenile Blueback Herring (Alosa Aestivalis): Phototactic Behavior And Population Dynamics, Douglas A. Dixon
Contributions To The Life History Of Juvenile Blueback Herring (Alosa Aestivalis): Phototactic Behavior And Population Dynamics, Douglas A. Dixon
Dissertations, Theses, and Masters Projects
This research investigated the relationship between juvenile abundance indexes (JAIs) for anadromous blueback herring (Alosa aestivalis) and abiotic factors (river flow and temperature) during the spawning and nursery period in the tidal freshwater areas of James, Pamunkey, Mattaponi, and Rappahannock Rivers in Virginia. Accomplishing this objective required the evaluation of the JAI methodology, specifically the effect of phototactic behavior on diel changes in the surface availability to the pushnet sampling gear, and obtaining population dynamics information (hatch dates, growth, natural mortality) during early life history from otolith microstructure of samples collected in 1991 and 1992. Mean catch-per-unit effort (CPUE) at …
Temporal Variablity Of The Pycnocline In The Mid-Chesapeake Bay, Linda Jane Frizzell-Makowski
Temporal Variablity Of The Pycnocline In The Mid-Chesapeake Bay, Linda Jane Frizzell-Makowski
Dissertations, Theses, and Masters Projects
Mixing and dispersion in a partially mixed estuary are driven by, among other processes, the gravitational circulation, wind-events and tides. These processes are important in the vertical and horizontal distribution and exchange of salinity, oxygen, nutrients, and organisms. The objective of this research was to examine the temporal variability of the pycnocline in the mid-Chesapeake Bay in response to forcing at subtidal and higher frequencies as observed in the spring of 1993. The largest change in the pycnocline was associated with meteorological forcing. Up-Bay wind stress and subsequent abatement of the wind stress produced a 5 meter displacement of the …
Gaseous Flux And Distribution Of Polycyclic Aromatic Hydrocarbons Across The Air-Water Interface Of Southern Chesapeake Bay, Kurt E. Gustafson
Gaseous Flux And Distribution Of Polycyclic Aromatic Hydrocarbons Across The Air-Water Interface Of Southern Chesapeake Bay, Kurt E. Gustafson
Dissertations, Theses, and Masters Projects
Gaseous fluxes of polycyclic aromatic hydrocarbons (PAHs) across the air-water interface of Southern Chesapeake Bay were calculated for the period January 1994 through May 1995 using a modified two-film model. Additionally, the distributions of PAHs between the vapor and aerosol phase in the atmosphere, and between the freely dissolved and suspended particulate phase in the water column were investigated. Net instantaneous gaseous fluxes of PAHs were determined to vary in direction and magnitude both spatially and temporally across the air-water interface of Southern Chesapeake Bay at four sites ranging from remote to urban and highly industrialized. The magnitude of gas …
Modeling Storm-Induced Sediment Transport On The Inner Shelf: Effects Of Bed Microstratigraphy, Baeck Oon Kim
Modeling Storm-Induced Sediment Transport On The Inner Shelf: Effects Of Bed Microstratigraphy, Baeck Oon Kim
Dissertations, Theses, and Masters Projects
Sediment transport during a storm event on the inner continental shelf was detailed through the development of models based on field experiments conducted at Duck, North Carolina in October 1994. A vertical one-dimensional model (1DV model) was developed by coupling the Grant and Madsen (1986) model with bed stratigraphy to consider real seabeds. Sediment was divided into seven size classes and fractional transport was estimated. Mixing depth and total depth from a simplified sediment conservation equation provided the basis for changing bottom sediment, sediment availability for transport, and armoring processes. These processes involve a feedback between hydrodynamics and bed stratigraphy. …
Demersal Predator Exposure To Toxic Organic Contaminants: Direct Effects Of Macrofauna In Trophic Transfer, Patrick Winfield Lay
Demersal Predator Exposure To Toxic Organic Contaminants: Direct Effects Of Macrofauna In Trophic Transfer, Patrick Winfield Lay
Dissertations, Theses, and Masters Projects
The bioaccumulation and metabolism of organic contaminants (PAH, PCB) by three estuarine polychaetes, Nereis succinea (Frey and Leuckart 1847), Paraprionospio pinnata (Ehlers 1901) and Polydora ligni (Webster 1879), and by the fish predator, spot (Leiostomus xanthurus Lacepede 1802), were examined in laboratory experiments. Variations in trophic transfer of these contaminants resulting from differences in prey and contaminant type were also investigated. Toxicokinetic modeling reveals that metabolism of organic contaminants by invertebrate species result in variations in uptake, metabolism and elimination rate constants. Incorporation of prey metabolism potential in kinetic models increases the latter's predictability of biota-sediment accumulation factors (BSAFs), or …
Issues Of Power And Centrality In United Methodist Ministers' Occupational Activities: Implications For Professional Education, Richard Bruce Osmann
Issues Of Power And Centrality In United Methodist Ministers' Occupational Activities: Implications For Professional Education, Richard Bruce Osmann
Dissertations, Theses, and Masters Projects
The purpose of this interview based qualitative study was to explore the influence that a plurality of social contexts, represented through United Methodist congregations in the Virginia Conference, have on the formation of ministers' occupational activities.;The study used a typology developed by Larry Blazer (1987) to identify the occupational activities practiced by parish ministers. The investigation weighted clergy's professional practice using Judith Hackman's (1985) concepts of power and centrality in her study institutions of higher education's budgeting process. Congregational representatives identified occupational activities that were central and peripheral to their congregation's mission. Clergy identified the occupational activities that received more …
Maintaining Diversity In The Shadows Of Conformity: Can A Systematic Attempt To Maintain A University's Distinctive Mission Override Societal Pressures For Conformity?, Delrina Marie Clarin
Maintaining Diversity In The Shadows Of Conformity: Can A Systematic Attempt To Maintain A University's Distinctive Mission Override Societal Pressures For Conformity?, Delrina Marie Clarin
Dissertations, Theses, and Masters Projects
The purpose of this study was to analyze the components of the University of Scranton's systematic program to develop and maintain a distinctive mission through Tierney's framework of organizational culture, and to analyze the congruence between the mission of the University of Scranton and the faculty's perception of the mission and their institutional activities.;The University of Scranton was chosen for three reasons: (1) Sporadic efforts to maintain its Catholic/Jesuit mission and identity had already been in place since 1977; (2) With the appointment of a Task Force on Identity and Mission in 1994, the administration is attempting to bring previous …
Managing Change For A Distance Learning Initiative: An Evaluation, Jeanie Pollard Kline
Managing Change For A Distance Learning Initiative: An Evaluation, Jeanie Pollard Kline
Dissertations, Theses, and Masters Projects
The purpose of this case study was to examine the degree to which those managing change for a distance learning initiative followed David Nadler's (1989) four action steps designed to reduce resistance in making the transition from the former operational state to a newly-created state.;The four action steps include providing opportunities for participation among employees, allowing employees to identify current operations that will not work in the new organizational state, rewarding behavior that assists in the transition, and allowing sufficient time for the change to take place. The findings in this study revealed that participation was the critical component that …
Performance Of School-Age Children Of Prenatal Cocaine Exposure: Five Case Studies, Susan Larson Wallace
Performance Of School-Age Children Of Prenatal Cocaine Exposure: Five Case Studies, Susan Larson Wallace
Dissertations, Theses, and Masters Projects
The purpose of this study was to examine the social and learning performance of school age children of prenatal cocaine exposure. The Behavioral Assessment System for Children (BASC) was used along with interviews, observations and document analysis for each individual case studied. The data collected through these methods was coded and examined for patterns and relationships in each case, and across cases.;Data analysis revealed that each case varied in the effects exhibited on a continuum from subtle to severe, as indicated in the literature. Social and behavioral patterns appeared to be most severely affected, while the language area was found …
Principals As Managers And Leaders: A Qualitative Study Of The Perspectives Of Selected Elementary School Principals, Dean S. T. Cascadden
Principals As Managers And Leaders: A Qualitative Study Of The Perspectives Of Selected Elementary School Principals, Dean S. T. Cascadden
Dissertations, Theses, and Masters Projects
The primary purpose of this study was to explore how selected elementary school principals described and defined their world in terms of leadership and management. There were three sub-areas of investigation under this primary purpose: (a) exploring the principals' conceptions about the constructs of leadership and management, (b) exploring the principals' beliefs about the role of their personal philosophies, goals, or values in relation to their practice, and (c) using content analysis to explore the language that principals use to describe themselves, their work and their schools. The theoretical perspective adopted for this study was that organizations are constructed human …
School-University Partnerships: An Exploration Of The Relationship, Daisy Bertha Wood
School-University Partnerships: An Exploration Of The Relationship, Daisy Bertha Wood
Dissertations, Theses, and Masters Projects
The purpose of this study was to investigate the accuracy of a particular model for collaboration when applied to a successful school-university partnership. A specific framework for establishing and maintaining successful school-university partnerships, proposed by Frank Wilbur of Syracuse University, was identified in the literature. Wilbur's model was selected as the conceptual framework for this study since it contains critical elements supported by at least four other researchers studying and writing on collaborative endeavors and was, in fact, the most comprehensive of any of the suggested conceptual frameworks. The answer to one overall research question was sought: to what extent …