Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Life Sciences (13)
- Oceanography and Atmospheric Sciences and Meteorology (11)
- Oceanography (10)
- Environmental Sciences (8)
- Physics (8)
-
- Computer Sciences (6)
- Marine Biology (5)
- Engineering (4)
- Fresh Water Studies (4)
- Biodiversity (3)
- Condensed Matter Physics (3)
- Earth Sciences (3)
- Natural Resources and Conservation (3)
- Optics (3)
- Animal Sciences (2)
- Aquaculture and Fisheries (2)
- Microbiology (2)
- Acoustics, Dynamics, and Controls (1)
- Aerospace Engineering (1)
- Animal Diseases (1)
- Atomic, Molecular and Optical Physics (1)
- Biochemistry, Biophysics, and Structural Biology (1)
- Biogeochemistry (1)
- Biophysics (1)
- Chemistry (1)
- Civil and Environmental Engineering (1)
- Diseases (1)
- Environmental Engineering (1)
- Environmental Health and Protection (1)
Articles 1 - 30 of 33
Full-Text Articles in Physical Sciences and Mathematics
Biomarker Responses In Fathead Minnows (Pimephales Promelas) During Exposure To Exceptional Quality Biosolids, Constance A. Sullivan
Biomarker Responses In Fathead Minnows (Pimephales Promelas) During Exposure To Exceptional Quality Biosolids, Constance A. Sullivan
Dissertations, Theses, and Masters Projects
No abstract provided.
Parity-Violation In Elastic Electron Scattering: A First Measurement Of The Parity-Violating Asymmetry At Q2 = 0.631 (Gev/C)2 At Backward Angle, Stephanie L. Bailey
Parity-Violation In Elastic Electron Scattering: A First Measurement Of The Parity-Violating Asymmetry At Q2 = 0.631 (Gev/C)2 At Backward Angle, Stephanie L. Bailey
Dissertations, Theses, and Masters Projects
The goal of Experiment E04-115 (the G0 backward angle measurement) at Jefferson Lab is to investigate the contributions of strange quarks to the fundamental properties of the nucleon. The experiment measures parity-violating asymmetries in elastic electron scattering off hydrogen and quasielastic electron scattering off deuterium at backward angles at Q2 = 0.631 (GeV/c)2 and Q 2 = 0.232 (GeV/c)2. The backward angle measurement represents the second phase of the G0 experiment. The first phase, Experiment E00-006 (the G0 forward angle experiment), measured parity-violating asymmetries in elastic electron scattering off hydrogen at forward angles over a Q 2 range of 0.1-1.0 …
Fluorescence Imaging Study Of Free And Impinging Supersonic Jets: Jet Structure And Turbulent Transition, Jennifer Ann Inman
Fluorescence Imaging Study Of Free And Impinging Supersonic Jets: Jet Structure And Turbulent Transition, Jennifer Ann Inman
Dissertations, Theses, and Masters Projects
A series of experiments into the behavior of underexpanded jet flows has been conducted at NASA Langley Research Center. This work was conducted in support of the Return to Flight effort following the loss of the Columbia. The tests involved simulating flow through a hypothetical breach in the leading edge of the Space Shuttle Orbiter along its reentry trajectory, with the goal of generating a data set with which other researchers can test and validate computational modeling tools. Two nozzles supplied with high-pressure gas were used to generate axisymmetric underexpanded jets exhausting into a low-pressure chamber. These nozzles had exit …
Shelf Sediment Dispersal Mechanisms And Deposition On The Waiapu River Shelf, New Zealand, Tara A. Kniskern
Shelf Sediment Dispersal Mechanisms And Deposition On The Waiapu River Shelf, New Zealand, Tara A. Kniskern
Dissertations, Theses, and Masters Projects
The Waiapu River, located on the North Island of New Zealand, drains a small catchment and has one of the highest sediment yields in the world. The river delivers most of its annual sediment load during floods into energetic coastal waters. These conditions are favorable for producing multiple sediment transport mechanisms, including transport in positively and negatively buoyant freshwater plumes, gravitydriven flows, and resuspension. Analyses of Waiapu River shelf seabed data showed that multiple transport mechanisms influence strata formation. Fluvial sediments are initially deposited at water depths shallower than 80 m before being remobilized and deposited at greater water depths. …
The Infection Dynamics Of Pav1 In The Caribbean Spiny Lobster Panulirus Argus, Caiwen Li
The Infection Dynamics Of Pav1 In The Caribbean Spiny Lobster Panulirus Argus, Caiwen Li
Dissertations, Theses, and Masters Projects
Panulirus argus Virus 1 (PaV1) is an emerging disease in Caribbean spiny lobster Panulirus argus. It is considered a threat to the lobster industry in the Florida Keys. In order to understand the infection dynamics of the PaV1 virus in the lobster host, a sensitive and specific fluorescence in situ hybridization (FISH) assay was developed for diagnosis of PaV1 in lobsters. The lower limit of detection using the 110-bp DNA probe in a dot-blot hybridization for PaV1 was 10 pg of cloned DNA template and 10 ng of genomic DNA extracted from hemolymph of diseased spiny lobster. The probe specifically …
Hypoxia And Macoma Balthica: Ecological Effects On A Key Infaunal Benthic Species, William Christopher Long
Hypoxia And Macoma Balthica: Ecological Effects On A Key Infaunal Benthic Species, William Christopher Long
Dissertations, Theses, and Masters Projects
Hypoxia, low dissolved oxygen, is an important environmental stressor in estuarine systems. In this dissertation, I examine the effects of hypoxia on the macrobenthic communities of the York and Rappahannock Rivers, Chesapeake Bay, USA, and in particular its effects on the infaunal clam Macoma balthica. A survey of the macrobenthic community was performed using box-coring before and after hypoxia in 2003 and 2004 in both rivers. Hypoxia was associated with a change in the macrobenthic community towards smaller, shorter-lived, opportunistic species; and a substantial decrease in biomass. M. balthica recruited into all areas of the river but suffered local extinction …
Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss
Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss
Dissertations, Theses, and Masters Projects
The eastern oyster, Crassostrea virginica, once an integral part of the ecology and economy of Chesapeake Bay, has been severely depleted. Factors leading to the decline of the eastern oyster include over-harvesting, environmental degradation and disease pressure caused by the protozoans Haplosporidium nelsoni and Perkinsus marinus, known commonly as MSX and Dermo, respectively. Studies regarding the feasibility of introducing a nonnative oyster to the Bay were initiated, and field-based research on an Asian oyster, Crassostrea ariakensis, suggested that it might be a viable species for introduction. Research surrounding the proposed introduction has focused on recommendations such as those from the …
Biogeochemistry And Phytoplankton Dynamics In The Ross Sea, Antarctica, Amy Rebecca Shields
Biogeochemistry And Phytoplankton Dynamics In The Ross Sea, Antarctica, Amy Rebecca Shields
Dissertations, Theses, and Masters Projects
The Ross Sea, Antarctica seasonal phytoplankton bloom is one of the largest in the Southern Ocean. This project focuses on the biological pump, which removes carbon from the surface ocean to the deep ocean through the settling of particulate organic matter, the advection of dissolved organic carbon, and active flux due to vertical migration of zooplankton. The objective of this study was to focus on three interrelated components of the biological pump including sedimentation, photosynthetic rates and grazing. The study was conducted in coordination with the Interannual Variability in the Antarctic-Ross Sea program, which covered the time period between 2001--2005. …
Boron Carbide Filled Neutron Shielding Textile Polymers, Derrick Anthony Manzlak
Boron Carbide Filled Neutron Shielding Textile Polymers, Derrick Anthony Manzlak
Dissertations, Theses, and Masters Projects
No abstract provided.
First-Principles Calculations Of Electric Field Gradients In Complex Perovskites, Dandan Mao
First-Principles Calculations Of Electric Field Gradients In Complex Perovskites, Dandan Mao
Dissertations, Theses, and Masters Projects
Various experimental and theoretical work indicate that the local structure and chemical ordering play a crucial role in the different physical behaviors of lead-based complex ferroelectrics with the ABO 3 perovskite structure. First-principles linearized augmented plane wave (LAPW) with the local orbital extension method within local density approximation (LDA) are performed on structural models of Pb(Zr1/2Ti1/2 )O3 (PZT), Pb(Sc1/2Ta1/2)O3 (PST), Pb(Sc2/3W1/3)O3 (PSW), and Pb(Mg 1/3Nb2/3)O3 (PMN) to calculate electric field gradients (EFGs). In order to simulate these disordered alloys, various structural models were constructed with different imposed chemical orderings and symmetries. Calculations were carried out as a function of B-site …
Magneto-Optical Imaging Of Superconducting Mgb2 Thin Films, Stephanie Maria Hummert
Magneto-Optical Imaging Of Superconducting Mgb2 Thin Films, Stephanie Maria Hummert
Dissertations, Theses, and Masters Projects
No abstract provided.
Tweakable Blockciphers Secure Against Generic Exponential Attacks, Elizabeth Ann Crump
Tweakable Blockciphers Secure Against Generic Exponential Attacks, Elizabeth Ann Crump
Dissertations, Theses, and Masters Projects
No abstract provided.
Environmental Factors And Typha Spp Dominance In Created Wetlands, Azure E. Bevington
Environmental Factors And Typha Spp Dominance In Created Wetlands, Azure E. Bevington
Dissertations, Theses, and Masters Projects
As created wetlands are becoming more common due to compensatory mitigation under section 404 of the Clean Water Act, it has become important to understand how the vegetation community and the soil nutrient availability develop over time. For a created wetland to replace the function of the destroyed natural wetland, the biogeochemical cycling and vegetation community must replicate the natural system. In this study, I sampled the vegetation community as well as the soil and porewater nutrient availability in four created wetlands in southeastern Virginia, constructed and managed by the Virginia Department of Transportation. All the sites used in this …
Trophic Ecology And Growth Dynamics Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, With Reference To Mycobacteriosis, Kathleen Anne Mcnamee
Trophic Ecology And Growth Dynamics Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, With Reference To Mycobacteriosis, Kathleen Anne Mcnamee
Dissertations, Theses, and Masters Projects
No abstract provided.
Feeding Ecology Of Atlantic Menhaden (Brevoortia Tyrannus) In Chesapeake Bay, Patrick D. Lynch
Feeding Ecology Of Atlantic Menhaden (Brevoortia Tyrannus) In Chesapeake Bay, Patrick D. Lynch
Dissertations, Theses, and Masters Projects
No abstract provided.
Acoustic Measurement And Modeling Of Waves In Estuarine And Coastal Environments, Justin P. Vandever
Acoustic Measurement And Modeling Of Waves In Estuarine And Coastal Environments, Justin P. Vandever
Dissertations, Theses, and Masters Projects
No abstract provided.
Measurement Of The Branching Fraction For The Decay Neutral Kaon(Long) Going To Pion-Antipion-Positron-Electron In The High M(Pi-Pi) Invariant Mass Region, Joshua J. Moss
Dissertations, Theses, and Masters Projects
A measurement of the branching fraction for the rare decay K0L → pi+pi-e +e- was performed using data collected from experiment E871 which ran at the AGS of Brookhaven National Laboratory. Analysis of the data revealed 27.7 +/- 7.4 signal events in the signal region, 0.4905 GeV < Mpipiee < 0.505 GeV together with 13.3 +/- 3.7 background events. The branching fractions of ( 8.5+/-2.3stat +/-1.0sys ) x 10-6 using the phenomenological model acceptance and ( 2.3+/-0.6stat +/-0.3sys ) x 10-6 using the chiral perturbation model represent the first measurements for K0L → pi+pi-e +e- in the dipion invariant mass region 0.475 GeV < Mpipi < 0.497 GeV. These results support the prediction of chiral perturbation theory rather than that of the phenomenological model.
Decoupling Method For Parallel Delaunay Two-Dimensional Mesh Generation, Leonidas Linardakis
Decoupling Method For Parallel Delaunay Two-Dimensional Mesh Generation, Leonidas Linardakis
Dissertations, Theses, and Masters Projects
Parallel mesh generation procedures that are based on geometric domain decompositions require the permanent separators to be of good quality (in terms of their angles and length), in order to maintain the mesh quality. The Medial Axis Domain Decomposition, an innovative geometric domain decomposition procedure that addresses this problem, is introduced. The Medial Axis domain decomposition is of high quality in terms of the formed angles, and provides separators of small size, and also good work-load balance. It presents for the first time a decomposition method suitable for parallel meshing procedures that are based on geometric domain decompositions.;The Decoupling Method …
The Effects Of Mercury On The Nesting Success And Return Rate Of Tree Swallows (Tachycineta Bicolor), Rebecka L. Brasso
The Effects Of Mercury On The Nesting Success And Return Rate Of Tree Swallows (Tachycineta Bicolor), Rebecka L. Brasso
Dissertations, Theses, and Masters Projects
No abstract provided.
A New Packet Filter: Fast Packet Filtering By Exploiting Cisc And Simd Isa, Zhenyu Wu
A New Packet Filter: Fast Packet Filtering By Exploiting Cisc And Simd Isa, Zhenyu Wu
Dissertations, Theses, and Masters Projects
No abstract provided.
Inactive Sulfide Mounds Of The Manus Basin: Invertebrate Composition And Potential For A Chemoautotrophic Food Web, Kristin Lynn Erickson
Inactive Sulfide Mounds Of The Manus Basin: Invertebrate Composition And Potential For A Chemoautotrophic Food Web, Kristin Lynn Erickson
Dissertations, Theses, and Masters Projects
No abstract provided.
Effects Of Mercury On Condition And Coloration Of Belted Kingfishers, Ariel Elizabeth White
Effects Of Mercury On Condition And Coloration Of Belted Kingfishers, Ariel Elizabeth White
Dissertations, Theses, and Masters Projects
No abstract provided.
Magnetization Dynamics And Anisotropy In Ferromagnetic/Antiferromagnetic Ni/Nio Bilayers, Andreas Petersen
Magnetization Dynamics And Anisotropy In Ferromagnetic/Antiferromagnetic Ni/Nio Bilayers, Andreas Petersen
Dissertations, Theses, and Masters Projects
No abstract provided.
Forward Secure Fuzzy Extractors, David Goldenberg
Forward Secure Fuzzy Extractors, David Goldenberg
Dissertations, Theses, and Masters Projects
No abstract provided.
Parallel Three-Dimensional Acoustic And Elastic Wave Simulation Methods With Applications In Nondestructive Evaluation, Kevin Edward Rudd
Parallel Three-Dimensional Acoustic And Elastic Wave Simulation Methods With Applications In Nondestructive Evaluation, Kevin Edward Rudd
Dissertations, Theses, and Masters Projects
In this dissertation, we present two parallelized 3D simulation techniques for three-dimensional acoustic and elastic wave propagation based on the finite integration technique. We demonstrate their usefulness in solving real-world problems with examples in the three very different areas of nondestructive evaluation, medical imaging, and security screening. More precisely, these include concealed weapons detection, periodontal ultrasography, and guided wave inspection of complex piping systems. We have employed these simulation methods to study complex wave phenomena and to develop and test a variety of signal processing and hardware configurations. Simulation results are compared to experimental measurements to confirm the accuracy of …
Parallel Generalized Delaunay Mesh Refinement, Andrey Nikolayevich Chernikov
Parallel Generalized Delaunay Mesh Refinement, Andrey Nikolayevich Chernikov
Dissertations, Theses, and Masters Projects
The modeling of physical phenomena in computational fracture mechanics, computational fluid dynamics and other fields is based on solving systems of partial differential equations (PDEs). When PDEs are defined over geometrically complex domains, they often do not admit closed form solutions. In such cases, they are solved approximately using discretizations of domains into simple elements like triangles and quadrilaterals in two dimensions (2D), and tetrahedra and hexahedra in three dimensions (3D). These discretizations are called finite element meshes. Many applications, for example, real-time computer assisted surgery, or crack propagation from fracture mechanics, impose time and/or mesh size constraints that cannot …
Mercury Exposure In Terrestrial Insectivorous Birds, Scott Lawrence Friedman
Mercury Exposure In Terrestrial Insectivorous Birds, Scott Lawrence Friedman
Dissertations, Theses, and Masters Projects
No abstract provided.
Spatial Beam Shaping Of High-Power Ultrashort Laser Pulses, Shuyan Zhang
Spatial Beam Shaping Of High-Power Ultrashort Laser Pulses, Shuyan Zhang
Dissertations, Theses, and Masters Projects
This thesis presents both theoretical and experimental studies of a diffractive beam shaping system for ultrashort high-power laser pulses.;A theoretical model is developed to simulate the reshaped intensity profiles for a 100-fs pulse with various energy levels. Both temporal evolution and spatial intensity distribution of the pulse at the target plane of the beam shaping system are calculated. Numerical simulation shows that after passing through the beam shaping system, the pulse front is significantly curved due to the propagation time delay, and the pulse duration time through the target plane is broadened because of the group velocity dispersion. However, for …
Effects Of Molecular Motion On Deuteron Magic Angle Spinning Nmr Spectra, Yuanyuan Huang
Effects Of Molecular Motion On Deuteron Magic Angle Spinning Nmr Spectra, Yuanyuan Huang
Dissertations, Theses, and Masters Projects
Solid state deuteron NMR experiments, especially magic angle spinning (MAS) and off-magic angle spinning (OMAS), are developed to explore dynamical systems. A theoretical discussion of interactions relevant for spin-1 nuclei is presented. Practical aspects of MAS/OMAS experiments are described an detail. The dominant quadrupolar coupling interaction in deuteron NMR has been simulated and the effects of multiple-frame molecular motions on MAS/OMAS spectra are taken into account in this calculation. Effects of chemical shift anisotropy are also simulated, and shown to be small under conditions of rapid sample spinning.;Two numerical methods, direct integration and an efficient simulation routine based on Floquet …
Assessing The Impacts Of Land Use Change On Hard Clam Aquaculture In Old Plantation Creek, Northampton County, Virginia, Matthew J. Strickler
Assessing The Impacts Of Land Use Change On Hard Clam Aquaculture In Old Plantation Creek, Northampton County, Virginia, Matthew J. Strickler
Dissertations, Theses, and Masters Projects
One of the main threats to water quality in the Chesapeake Bay is contamination by bacterial loading from point and non-point sources. While only very high levels of fecal bacteria (greater than 200 MPN/100ml) indicate the potential of a health threat to humans from contact with water, lower concentrations (14 MPN/100 ml) make the shellfish from contaminated waters unfit for human consumption. Many nearshore areas that are vulnerable to bacterial contamination also are suitable for the propagation of shellfish, including the hard clam (Mercenaria mercenaria). This is especially true on Virginia’s Eastern Shore, where shallow, sheltered waters with optimal salinity …