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Dissertations, Theses, and Masters Projects

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Articles 901 - 930 of 1876

Full-Text Articles in Physical Sciences and Mathematics

Mycobacteriosis In Striped Bass, Morone Saxatilis, From Virginia Waters Of Chesapeake Bay, Jennifer L. Cardinal Jan 2001

Mycobacteriosis In Striped Bass, Morone Saxatilis, From Virginia Waters Of Chesapeake Bay, Jennifer L. Cardinal

Dissertations, Theses, and Masters Projects

No abstract provided.


Life History Attributes Of Mid-Atlantic Menidia Menidia (Pisces: Atherinidae) And A Comparison With Northern (Massachusetts) And Southern (South Carolina) Populations, Richard K. Holmquist Jan 2001

Life History Attributes Of Mid-Atlantic Menidia Menidia (Pisces: Atherinidae) And A Comparison With Northern (Massachusetts) And Southern (South Carolina) Populations, Richard K. Holmquist

Dissertations, Theses, and Masters Projects

No abstract provided.


Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe Jan 2001

Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe

Dissertations, Theses, and Masters Projects

No abstract provided.


Morphological Variation Of Three Populations Of The Veined Rapa Whelk, Rapana Venosa, An Invasive Predatory Gastropod Species, Rebecca A. Green Jan 2001

Morphological Variation Of Three Populations Of The Veined Rapa Whelk, Rapana Venosa, An Invasive Predatory Gastropod Species, Rebecca A. Green

Dissertations, Theses, and Masters Projects

No abstract provided.


Sediment Budgets, Estuarine Sediment Loads, And Wetland Sediment Storage At Watershed Scales, York River Watershed, Virginia, Julie D. Herman Jan 2001

Sediment Budgets, Estuarine Sediment Loads, And Wetland Sediment Storage At Watershed Scales, York River Watershed, Virginia, Julie D. Herman

Dissertations, Theses, and Masters Projects

Three separate but related aspects of sediment allocation in a river/estuarine system were examined. The main purpose was to compare sediment budgets for a series of eleven nested sub-watersheds as a function of watershed size, ranging from 65 to 6900 km2. The approach quantified six budget components: upland erosion; stream bank erosion; colluvial storage; wetland storage; stream channel erosion and storage; and sediment flux at the outlets. Three budgets were developed for each sub-watershed to examine the relative proportions of budget components, budget sensitivity (the influence of individual components on the overall budget), and the uncertainty of budget components. The …


Post-Glacial Sedimentation In A River -Dominated Epicontinental Shelf: The Yellow Sea Example, Jing-Pu Liu Jan 2001

Post-Glacial Sedimentation In A River -Dominated Epicontinental Shelf: The Yellow Sea Example, Jing-Pu Liu

Dissertations, Theses, and Masters Projects

The North Yellow Sea (NYS) and South Yellow Sea (SYS), stretching from the Bohai Sea in the north to the East China Sea (ECS) in the south, represents an end member of modern epicontinental seas. Because of its shallow depths, the Yellow Sea was entirely exposed subaerially during the last glacial maximum. The new post-glacial sea-level curve derived from an extensive local dataset shows a series of rapid flooding events (12--45 mm/y), separated by a series of slow rises (2--6 mm/y). By about 15 ka, sea level had reached -100 m, and seawater entered the SYS. A rapid rise during …


Modeling Of Critically-Stratified Gravity Flows: Application To The Eel River Continental Shelf, Northern California, Malcolm E. Scully Jan 2001

Modeling Of Critically-Stratified Gravity Flows: Application To The Eel River Continental Shelf, Northern California, Malcolm E. Scully

Dissertations, Theses, and Masters Projects

An analytical and numerical model are presented and applied to predict gravitydriven transport and deposition of fluid mud layers that form within the wave boundary layer on the continental shelf off the Eel River in northern California. Observations indicate that following floods of the Eel River down-slope transport of fluid mud trapped within the wave boundary layer is the dominant across-shelf transport mechanism. The models are based upon the assumption that following significant floods, an abundant supply of easily suspended fine sediment is delivered to the coastal ocean, allowing a negative feedback mechanism to maintain the near-bed Richardson number at …


An Examination Of Potential Conflict Between Sav And Hard Clam Aquaculture In The Lower Chesapeake Bay, Helen Woods Jan 2001

An Examination Of Potential Conflict Between Sav And Hard Clam Aquaculture In The Lower Chesapeake Bay, Helen Woods

Dissertations, Theses, and Masters Projects

Natural resource mangers may find themselves in a conflict of interest over the management of shallow subaqueous bottom when they attempt to promote both hard clam (Mercenaria mercenaria) aquaculture and the growth of submersed aquatic vegetation (SAV) (Zostera marina and Ruppia maritima). This project examines the issue of bottom use conflict along the Lower Eastern Shore of the Chesapeake Bay in a managerial and scientific context in an attempt to develop a solution to this conflict. First, it examines historical trends in clam aquaculture and SAV growth in the study area. Habitat suitability models are then developed to predict optimal …


Cobia (Rachycentron Canadum) Aquaculture: Captive Growth Rates And Product Quality Evaluation, David Patrick Kilduff Jan 2001

Cobia (Rachycentron Canadum) Aquaculture: Captive Growth Rates And Product Quality Evaluation, David Patrick Kilduff

Dissertations, Theses, and Masters Projects

No abstract provided.


A Descriptive Study Of The Reproductive Biology Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Erica S. Westcott Jan 2001

A Descriptive Study Of The Reproductive Biology Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Erica S. Westcott

Dissertations, Theses, and Masters Projects

No abstract provided.


Reproductive Biology Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay, Elizabeth Shaw Watkins Jan 2001

Reproductive Biology Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay, Elizabeth Shaw Watkins

Dissertations, Theses, and Masters Projects

No abstract provided.


Persistent Organic Pollutant Transport And Fate: Assessment By Molecular Tracers, Padma T. Venkatraman Jan 2001

Persistent Organic Pollutant Transport And Fate: Assessment By Molecular Tracers, Padma T. Venkatraman

Dissertations, Theses, and Masters Projects

Persistent organic pollutants (POPs) such as the organochlorine pesticide hexachlorocyclohexane (HCH) may undergo atmospheric transport and accumulate in regions remote from the source. It is important to develop techniques to help apportion source and identify transport or transformation processes to which HCHs and other mobile POPs may be subjected. Molecular tracers such as compound specific stable isotope and enantiomer ratios (ERs) may prove valuable in studying POP fate and transport. The objective of this study was to further develop the use of these two novel geochemical tools to evaluate the sources, transport and environmental fate of POPs, in the context …


Topics In Physics Beyond The Standard Model, Alfredo Aranda Jan 2001

Topics In Physics Beyond The Standard Model, Alfredo Aranda

Dissertations, Theses, and Masters Projects

In this dissertation we address three issues related to physics beyond the Standard model: flavor and the use of discrete gauge symmetries, the dynamical breaking of electroweak symmetry, and the addition of a U(1) gauge symmetry to the Standard model in order to suppress proton decay. We present: (i) A model of flavor based on the double tetrahedral group that leads to acceptable quark and lepton masses as well as mixing angles. Furthermore it gives solutions for the atmospheric and solar neutrino problems. (ii) A model of bosonic topcolor in which the breaking of electroweak symmetry occurs dynamically through the …


Broadcast Distributed Shared Memory, Philip Ragner Auld Jan 2001

Broadcast Distributed Shared Memory, Philip Ragner Auld

Dissertations, Theses, and Masters Projects

Distributed shared memory (DSM) provides the illusion of shared memory processing to programs running on physically distributed systems. Many of these systems are connected by a broadcast medium network such as Ethernet. In this thesis, we develop a weakly coherent model for DSM that takes advantage of hardware-level broadcast. We define the broadcast DSM model (BDSM) to provide fine-grained sharing of user-defined locations. Additionally, since extremely weak DSM models are difficult to program, BDSM provides effective synchronization operations that allow it to function as a stronger memory. We show speedup results for a test suite of parallel programs and compare …


Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer Jan 2001

Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer

Dissertations, Theses, and Masters Projects

Multi Angle Laser Light Scattering (MALLS) and Frequency Dependent Electromagnetic Sensing (FDEMS) provide unique characterizations of polymer systems during cure and use-aging. This research illustrates how MALLS is an extremely accurate technique for absolute characterization of macromolecules, giving molecular weight and size information that other widely used and accepted techniques are incapable of measuring. Application of MALLS to monitoring the changing state of a polyamide-11 system in a water aging environment led to the discovery of an equilibrium molecular weight which is the result of two competing reactions, hydrolysis-degradation and a newly discovered recombination-polymerization reaction. The discovery of this recombination …


Virtual Path Bandwidth Distribution And Capacity Allocation With Bandwidth Sharing, Karen Marie Anewalt Jan 2001

Virtual Path Bandwidth Distribution And Capacity Allocation With Bandwidth Sharing, Karen Marie Anewalt

Dissertations, Theses, and Masters Projects

Broadband high-speed networks, such as B-ISDN, are expected to play a dominant role in the future of networking due to their capability to service a variety of traffic types with very different bandwidth requirements such as video, voice and data. to increase network efficiency in B-ISDN and other such connection oriented networks, the concept of a virtual path (VP) has been proposed and studied in the literature. A VP is a permanent or semi-permanent reservation of capacity between two nodes. Using VPs can potentially reduce call setup delays, simplify hardware, provide quality of service performance guarantees, and reduce disruption in …


Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko Jan 2001

Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko

Dissertations, Theses, and Masters Projects

The characterization of narrow distributions of structural and motional parameters, and their evolution during the broad glass transition, is performed for deuterated PAMAM dendrimer salts using solid state NMR. The broadening of deuteron quadrupole echo (QE) lineshapes is consistent with the presence of narrow hydrogen bond length distribution (sigmar < 0.25 A) at the spacer amide and branching tertiary amine sites. The temperature dependent averaging of the experimental lineshapes is explained on the basis of fast planar librations in the dendrimer interior, and fast rotation and intermediate regime libration (in an asymmetric cone) of the dendrimer termini. The amplitudes of libration are temperature dependent and higher for low generation dendrimers, while librational rates show Arrhenius behavior only within the glass transition region. In this region, the width of log-normal distribution of rates increases with temperature at sites associated with chlorine counterions. The largest distributions are still less than one order of magnitude wide, unlike the dendrimer in solution or the linear polymers. Interpenetrated low generations (G < 3), uniform intermediate generations (G = 3--5) with surface network, and backfolded high generations (G > 5), are distinguished by interior and termini dynamics.;In the regime of fast motion QE lineshapes are highly sensitive to the presence of narrow structural and motional parameter distributions, and provide constraints on motional geometry independent of rates. The precise characterization of narrow log-normal rate distributions in the intermediate regime can be …


Single Positive Pion Electroproduction In The First And Second Resonance Regions Using Clas, Hovanes Egiyan Jan 2001

Single Positive Pion Electroproduction In The First And Second Resonance Regions Using Clas, Hovanes Egiyan

Dissertations, Theses, and Masters Projects

The study of single pion electroproduction can provide valuable information on the structure of the nucleon and its excited states. Although these reactions have been studied for decades, never has the npi + channel been measured over the complete phase space of the reaction. The CEBAF Large Acceptance Spectrometer (CLAS) located in Hall B of Jefferson Lab is well-suited for conducting these measurements. The CLAS data were taken using a 1.515 GeV electron beam incident on a liquid H 2 target. The cross sections have been extracted, and their &phis;-dependence has been fit to obtain the sigmaTT, sigma TL and …


Characterization Of Cyclic And Linear Dipeptides, Christine Michelle Howard Jan 2001

Characterization Of Cyclic And Linear Dipeptides, Christine Michelle Howard

Dissertations, Theses, and Masters Projects

No abstract provided.


The Synthesis And Characterization Of Cu(I) Networks With Heterocyclic Bridging Ligands, Jonathan Timothy Maeyer Jan 2001

The Synthesis And Characterization Of Cu(I) Networks With Heterocyclic Bridging Ligands, Jonathan Timothy Maeyer

Dissertations, Theses, and Masters Projects

No abstract provided.


Measurement Of The Strange Sea Of The Proton, Gary A. Rutledge Jan 2001

Measurement Of The Strange Sea Of The Proton, Gary A. Rutledge

Dissertations, Theses, and Masters Projects

The differential cross section for elastic scattering of longitudinally-polarized electrons from protons exhibits a parity-violating asymmetry, due to the interference between weak and electromagnetic amplitudes. The asymmetry is extracted from the detector counting rates as APV = ( Dr - Dl)/(Dr + D l) where Drl are related to the right (left) differential cross sections sigmar, sigmal respectively. Thus APV = (sigmar - sigma l)/(sigmar + sigmal) for right-handed and left-handed electrons. This asymmetry is sensitive to the presence of strange sea quarks in the proton, in particular to the strange vector matrix elements GsE and GsM .;In an experiment …


A Study Of The Aging Of Polyamide-11 Based On Molecular Weight Measurements, Yao Lin Jan 2000

A Study Of The Aging Of Polyamide-11 Based On Molecular Weight Measurements, Yao Lin

Dissertations, Theses, and Masters Projects

No abstract provided.


Sand- And Clay-Size Mineralogy Of The Ganges And Brahmaputra Rivers: Records Of River Switching And Late-Quaternary Climate Change, David Carlson Heroy Jan 2000

Sand- And Clay-Size Mineralogy Of The Ganges And Brahmaputra Rivers: Records Of River Switching And Late-Quaternary Climate Change, David Carlson Heroy

Dissertations, Theses, and Masters Projects

No abstract provided.


Osteology, Phylogeny, And Biogeography Of The Marine Fish Family Ephippidae (Perciformes, Acanthuroidei), With Comments On Sister Group Relationships, Martin Ray Cavalluzzi Jan 2000

Osteology, Phylogeny, And Biogeography Of The Marine Fish Family Ephippidae (Perciformes, Acanthuroidei), With Comments On Sister Group Relationships, Martin Ray Cavalluzzi

Dissertations, Theses, and Masters Projects

The marine fish family Ephippidae comprises eight genera and 15 species of extant fishes. Spadefishes or batfishes inhabit nearshore tropical to temperate waters. They are almost circumglobal in distribution, with the highest diversity in the Indo-west Pacific and the lowest diversity in the east Pacific and west Atlantic. Fifty-nine potentially informative morphological characters, 10 outgroup taxa, and eight ingroup taxa (i.e., genera) were used to explore sister group hypotheses to the Ephippidae, as well as generate a phylogeny of the Ephippidae. Seven constraint tree analyses were utilized to examine various sister group hypotheses based on previous morphological and molecular analyses …


Maturation And Repeat Spawning By American Shad In The York River, Virginia, Kristin L. Maki Jan 2000

Maturation And Repeat Spawning By American Shad In The York River, Virginia, Kristin L. Maki

Dissertations, Theses, and Masters Projects

No abstract provided.


The Habitat Utilization Of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) At Buck Island Reef National Monument, St Croix, U.S Virgin Islands, Roy A. Pemberton Jan 2000

The Habitat Utilization Of Juvenile Hawksbill Sea Turtles (Eretmochelys Imbricata) At Buck Island Reef National Monument, St Croix, U.S Virgin Islands, Roy A. Pemberton

Dissertations, Theses, and Masters Projects

No abstract provided.


A Framework For Construction And Analysis Of Juvenile Abundance Indices For American Shad (Alosa Sapidissima) In The York River, Virginia, Mary Lynn Aiken Jan 2000

A Framework For Construction And Analysis Of Juvenile Abundance Indices For American Shad (Alosa Sapidissima) In The York River, Virginia, Mary Lynn Aiken

Dissertations, Theses, and Masters Projects

No abstract provided.


Seasonal Residence, Movement, And Activity Patterns Of Adult Tautog, Tautoga Onitis, In Lower Chesapeake Bay, Michael D. Arendt Jan 2000

Seasonal Residence, Movement, And Activity Patterns Of Adult Tautog, Tautoga Onitis, In Lower Chesapeake Bay, Michael D. Arendt

Dissertations, Theses, and Masters Projects

No abstract provided.


Biology Of The Spotted Seatrout, Cynoscion Nebulosus, In The Chesapeake Bay Region, Thomas F. Ihde Jan 2000

Biology Of The Spotted Seatrout, Cynoscion Nebulosus, In The Chesapeake Bay Region, Thomas F. Ihde

Dissertations, Theses, and Masters Projects

No abstract provided.


The Attempted Synthesis Of A Phenolphthalein-Capped Beta-Cyclodextrin, Susan Elizabeth Miller Jan 2000

The Attempted Synthesis Of A Phenolphthalein-Capped Beta-Cyclodextrin, Susan Elizabeth Miller

Dissertations, Theses, and Masters Projects

No abstract provided.