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Articles 1 - 30 of 39
Full-Text Articles in Physical Sciences and Mathematics
A Numerical Simulation And Statistical Modeling Of High Intensity Radiated Fields Experiment Data, Laura Smith
A Numerical Simulation And Statistical Modeling Of High Intensity Radiated Fields Experiment Data, Laura Smith
Dissertations, Theses, and Masters Projects
No abstract provided.
Assessment Of Development Impacts On Coastal Zone: Integrated Approach, Northampton County, Eastern Shore, Virginia, Sarunas Zableckis
Assessment Of Development Impacts On Coastal Zone: Integrated Approach, Northampton County, Eastern Shore, Virginia, Sarunas Zableckis
Dissertations, Theses, and Masters Projects
No abstract provided.
Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer
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 …
Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin
Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin
Dissertations, Theses, and Masters Projects
The interactive effects of humic acids (HAs) and salinity on the bioavailability and toxicity of the pesticides chlorpyrifos and 4,4'-dichlorodiphenyltrichloroethane (DDT) were investigated. The effects of various HAs on the toxicity of chlorpyrifos were initially assessed with the chronic MicrotoxRTM test. Environmentally relevant concentrations of Aldrich, Peat, Leonardite and Suwannee River HAs had no significant effect on the toxicity of either chlorpyrifos or copper (Cu), the test's positive control. as reductions in contaminant toxicity had previously been reported for some contaminants by HAs, it appeared that salinity might be a mitigating factor. Thus salinity effects were further investigated with Aldrich …
Modeling Of Critically-Stratified Gravity Flows: Application To The Eel River Continental Shelf, Northern California, Malcolm E. Scully
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 …
Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio
Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio
Dissertations, Theses, and Masters Projects
Vitellogenin (VTG) is widely used as a biomarker for environmental estrogens and reproductive disruption in fish. Vitellogenesis is the process by which yolk is formed. The endpoint is most sensitive in male fish where vitellogenesis is an abnormal process. Research examining effects of environmental mixtures of chemicals (e.g. creosote) on vitellogenesis is limited. This study examines plasma VTG expression in both male and female mummichog, Fundulus heteroclitus, collected from a creosote-contaminated site and two reference sites in lower Chesapeake Bay, USA, and in wild-caught male reference fish exposed in the laboratory to creosote-contaminated sediment. Further, this study uses tissue somatic …
Cobia (Rachycentron Canadum) Aquaculture: Captive Growth Rates And Product Quality Evaluation, David Patrick Kilduff
Cobia (Rachycentron Canadum) Aquaculture: Captive Growth Rates And Product Quality Evaluation, David Patrick Kilduff
Dissertations, Theses, and Masters Projects
No abstract provided.
Topics In Physics Beyond The Standard Model, Alfredo Aranda
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 …
Phenomenology Of The Su(2)(L) X Su(2)(I) X U(1)(Y) X U(1)(Y') Model, Shuquan Nie
Phenomenology Of The Su(2)(L) X Su(2)(I) X U(1)(Y) X U(1)(Y') Model, Shuquan Nie
Dissertations, Theses, and Masters Projects
We consider the effective low-energy SU(2) L x SU(2)I x U(1)Y x U(1)Y' model, which is based on the E6 grand unification theory. SU(2)I is a subgroup of SU(3) R and commutes with the electric charge operator.;Higgs bosons in the Standard Model and two-Higgs doublet models are reviewed and studied first. The flavor-changing neutral currents and their effects on the anomalous magnetic moment of the muon are discussed. Bounds on masses of Higgs bosons are obtained by requiring that the vacuum is stable and perturbation theory is valid up to a large scale. We introduce Higgs multiplets including two neutral …
Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko
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 …
Measurement Of The Strange Sea Of The Proton, Gary A. Rutledge
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 …
Morphological Variation Of Three Populations Of The Veined Rapa Whelk, Rapana Venosa, An Invasive Predatory Gastropod Species, Rebecca A. Green
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.
Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter
Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter
Dissertations, Theses, and Masters Projects
No abstract provided.
Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe
Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe
Dissertations, Theses, and Masters Projects
No abstract provided.
Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly
Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly
Dissertations, Theses, and Masters Projects
No abstract provided.
The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen
The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen
Dissertations, Theses, and Masters Projects
Most benthic invertebrates and reef-associated fish undergo a dispersive, planktonic larval stage prior to settlement and metamorphosis into the juvenile and adult stages. In some species, settlement may be decoupled from adult abundance at local spatial scales if hydrodynamic conditions or larval behavior do not promote local retention. Similarly, spatial variability in postsettlement mortality or secondary dispersal by juveniles and adults may decouple spatial patterns of adult abundance from those of settlement. as a consequence, spatial patterns of settlement and adult abundance may be functionally related in a complex fashion. Whether biotic/environmental factors control spatial patterns of abundance may have …
Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez
Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez
Dissertations, Theses, and Masters Projects
The stress protein response has been proposed as a general indicator of exposure to stress as their expression might integrate overall biological impact and interactions among multiple stressors. as a marker of contaminant effects, a major advantage is the premise of higher sensitivity over other indices such as condition index, scope for growth and survival. Laboratory exposure to suspended field contaminated sediments (SFCS) elicited a stress protein response (HSP70) in the eastern oyster, ( Crassostrea virginica). The stress response probably resulted from the combined effect of various contaminants including PAHs, metals and PCBs. Exposure to 1--2g suspended clay particles spiked …
Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer
Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer
Dissertations, Theses, and Masters Projects
A computational framework is built and demonstrated which is capable of testing plant growth strategies. The framework consists of Vgrass, a carbon based simulation model of a single Zostera marina plant, and the genetic algorithm (GA). Vgrass is based on published seagrass models, published photosynthetic data, and general plant physiology information. The model grows individual leaves whose initiation times are based on degree-day intervals. Leaf size is computed and combined with shoot density to compute population self shading. Leaf length is an emergent property since leaf growth is limited by light attenuation caused by self shading. The model is able …
Mycobacteriosis In Striped Bass, Morone Saxatilis, From Virginia Waters Of Chesapeake Bay, Jennifer L. Cardinal
Mycobacteriosis In Striped Bass, Morone Saxatilis, From Virginia Waters Of Chesapeake Bay, Jennifer L. Cardinal
Dissertations, Theses, and Masters Projects
No abstract provided.
Virtual Path Bandwidth Distribution And Capacity Allocation With Bandwidth Sharing, Karen Marie Anewalt
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 …
Algorithms For Operations On Probability Distributions In A Computer Algebra System, Diane Lynn Evans
Algorithms For Operations On Probability Distributions In A Computer Algebra System, Diane Lynn Evans
Dissertations, Theses, and Masters Projects
In mathematics and statistics, the desire to eliminate mathematical tedium and facilitate exploration has lead to computer algebra systems. These computer algebra systems allow students and researchers to perform more of their work at a conceptual level. The design of generic algorithms for tedious computations allows modelers to push current modeling boundaries outward more quickly.;Probability theory, with its many theorems and symbolic manipulations of random variables is a discipline in which automation of certain processes is highly practical, functional, and efficient. There are many existing statistical software packages, such as SPSS, SAS, and S-Plus, that have numeric tools for statistical …
Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern
Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern
Dissertations, Theses, and Masters Projects
No abstract provided.
Sub-Pixel Techniques To Improve Spatial Resolution, Mark Robert Idema
Sub-Pixel Techniques To Improve Spatial Resolution, Mark Robert Idema
Dissertations, Theses, and Masters Projects
Image acquisition using a scene sampling device generally results in a loss of fidelity in the acquired image, particularly if the scene contains high frequency features. Acquired images are also degraded by the blurring effects of acquisition filtering, image reconstruction, and additive noise effects. to compensate for these degradations, a digital restoration filter that attempts to partially eliminate the blurring while avoiding amplification of the noise effects is needed. In addition, to compensate for undersampling, a subpixel technique known as microscanning is required. This dissertation provides research into the spatial resolution enhancement of digital images based on subpixel techniques that …
Single Positive Pion Electroproduction In The First And Second Resonance Regions Using Clas, Hovanes Egiyan
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
Characterization Of Cyclic And Linear Dipeptides, Christine Michelle Howard
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
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 …
Persistent Organic Pollutant Transport And Fate: Assessment By Molecular Tracers, Padma T. Venkatraman
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 …
An Examination Of Potential Conflict Between Sav And Hard Clam Aquaculture In The Lower Chesapeake Bay, Helen Woods
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 …
A Descriptive Study Of The Reproductive Biology Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Erica S. Westcott
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
Reproductive Biology Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay, Elizabeth Shaw Watkins
Dissertations, Theses, and Masters Projects
No abstract provided.