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Articles 1 - 30 of 47
Full-Text Articles in Physical Sciences and Mathematics
The Primary Source Of Environmental Concern: New Environmental Paradigm Or Presumed Vested Interest Based On Area Of Residence?, Scott Christopher Ramsey
The Primary Source Of Environmental Concern: New Environmental Paradigm Or Presumed Vested Interest Based On Area Of Residence?, Scott Christopher Ramsey
Dissertations, Theses, and Masters Projects
No abstract provided.
Shellfish Culture Area Designation Protocol Development, Orelia Eleta Merchant
Shellfish Culture Area Designation Protocol Development, Orelia Eleta Merchant
Dissertations, Theses, and Masters Projects
No abstract provided.
Impact Of Artificial Reef Associates On Macrobenthic Community Structure In Florida Bay, Heinz Michael Proft
Impact Of Artificial Reef Associates On Macrobenthic Community Structure In Florida Bay, Heinz Michael Proft
Dissertations, Theses, and Masters Projects
No abstract provided.
Crassostrea Virginica On Constructed Intertidal Oyster Reefs: The Effects Of Tidal Height And Substrate Level On Settlement, Growth, And Mortality, Ian K. Bartol
Dissertations, Theses, and Masters Projects
No abstract provided.
Occurrence, Fate And Effects Of Polychlorinated Terphenyls In An Estuarine Environment, Kathryn Gallagher
Occurrence, Fate And Effects Of Polychlorinated Terphenyls In An Estuarine Environment, Kathryn Gallagher
Dissertations, Theses, and Masters Projects
Aroclor 5432, a mixture of polychlorinated terphenyls (PCT), was detected in sediment and several biological compartments including: saltmarsh cordgrass (Spartina alterniflora), American oysters (Crassostrea virginica), red-jointed fiddler crabs (Uca minax), wharf crabs (Sesarma reticulatum) and mummichogs (Fundulus heteroclitus) collected from Tabbs Creek. This tidal creek is located in the southern Chesapeake Bay region. Species from several phyla were selected in order to examine PCT accumulation in physiologically and ecologically different organisms. In general, PCT concentrations in sediment and biota decreased with distance downstream from the PCT outfall. The organism with the highest mean concentration (18,300 &\mu&g/kg dry weight) was the …
Beam Dynamics In The Cebaf Superconducting Cavities, Zenghai Li
Beam Dynamics In The Cebaf Superconducting Cavities, Zenghai Li
Dissertations, Theses, and Masters Projects
This work is a study of beam dynamics in the CEBAF superconducting cavities under the influence of the fields generated by externally applied RF and beam particles.;A full 3-D modeling of the CEBAF 5-cell superconducting cavity is carried out. Details of the modeling with MAFIA are discussed. Multipole fields due to the asymmetric couplers are studied by means of 3-D Fourier transforms. The cavity steering and focusing of the multipole fields are studied. Experimental measurements of these effects are performed to validate the modeling. Evaluation of the cavity misalignment is discussed. The emittance degradation effects in the CEBAF superconducting linacs …
Acid Dissociation Of Chloroguaiacols And Ph Dependent Sorption To Estuarine Sediments, Jennifer Lisa Gundersen
Acid Dissociation Of Chloroguaiacols And Ph Dependent Sorption To Estuarine Sediments, Jennifer Lisa Gundersen
Dissertations, Theses, and Masters Projects
Chloroguaiacols are common components of bleached kraft pulp mill effluent known to bioaccumulate in aquatic organisms, and sorb onto particulate material and sediments. Ionization properties of the chloroguaiacols must be known in order to explain their sorptive behavior in aquatic systems. to obtain this information, thermodynamic acid dissociation constants (p&K\sb{lcub}\rm a{rcub})& of guaiacol (o-methoxyphenol) and nine chloroguaiacols have been determined by spectrophotometric methods. These experimental p&K\sb{lcub}\rm a{rcub}& values have been compared with literature values, values predicted by the Hammett equation and predictions by quantum chemical calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators. Experimental and predicted acidities were …
A Comparison Of Three Wetland Evaluation Methods In Their Assessment Of Nontidal Wetlands In The Coastal Plain Of Virginia, Melissa Claire Chaun
A Comparison Of Three Wetland Evaluation Methods In Their Assessment Of Nontidal Wetlands In The Coastal Plain Of Virginia, Melissa Claire Chaun
Dissertations, Theses, and Masters Projects
No abstract provided.
Studies On Processes Controlling The Input Of Agricultural Chemicals In Groundwater To Surface Waters, Edward Laurence Libelo
Studies On Processes Controlling The Input Of Agricultural Chemicals In Groundwater To Surface Waters, Edward Laurence Libelo
Dissertations, Theses, and Masters Projects
This dissertation describes several studies of groundwater quality, the fate and transport of nutrients and atrazine in groundwater systems and physical processes at the sediment-water interface which impact on groundwater discharge. Groundwater monitoring wells were installed at the Goodwins Island and Catlett Island NERRS sites in Virginia and agricultural, suburban and forest land use sites in the York and James River Basins. Groundwater was analyzed for nutrients, pH, salinity and trace organics. Shoreline land use, associated nutrient loading and an estimate of total groundwater flux suggest that groundwater contributes up to 30% of the total nitrogen input to the Chesapeake …
Effects Of Simulated Sediment Resuspension Events On The Abundance Of Water Column Bacteria Of Tomales Bay, California, Christopher J. Collumb
Effects Of Simulated Sediment Resuspension Events On The Abundance Of Water Column Bacteria Of Tomales Bay, California, Christopher J. Collumb
Dissertations, Theses, and Masters Projects
No abstract provided.
Mechanisms Of Poly(Vinyl Chloride) Fire Retardance And Smoke Suppression Induced By Copper Additives, Jong Paul Jeng
Mechanisms Of Poly(Vinyl Chloride) Fire Retardance And Smoke Suppression Induced By Copper Additives, Jong Paul Jeng
Dissertations, Theses, and Masters Projects
The purpose of this study was to elucidate the mechanisms of PVC fire retardance and smoke suppression induced by copper additives.;The experimental approaches involved: (1) the use of activated copper (Cu{dollar}\sp0{dollar}) to study PVC model-compound reactions and the crosslinking of PVC and (2) the pyrolysis of PVC model compounds in the presence of several copper additives in order to examine all of the possible chemical reactions involved in the formation of heavy products.;The results obtained from experiments with activated copper and allylic chloride model compounds suggest that the reductive coupling mechanism is a viable process in PVC. The Cu{dollar}\sp0{dollar} that …
The Effects Of Hook Type On The Hooking Mortality Of Two Size Classes Of Summer Flounder, Paralichthys Dentatus, Tracy D. Holton
The Effects Of Hook Type On The Hooking Mortality Of Two Size Classes Of Summer Flounder, Paralichthys Dentatus, Tracy D. Holton
Dissertations, Theses, and Masters Projects
No abstract provided.
Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill
Genetic Relationships Among Geographically Isolated Populations Of Bluefish (Pomatamus Saltatrix), Catherine N. O'Neill
Dissertations, Theses, and Masters Projects
No abstract provided.
A Numerical Model Of The Global Carbon Cycle To Predict Atmospheric Carbon Dioxide Concentrations, Alexis Demitrios Kambis
A Numerical Model Of The Global Carbon Cycle To Predict Atmospheric Carbon Dioxide Concentrations, Alexis Demitrios Kambis
Dissertations, Theses, and Masters Projects
A numerical model of the global carbon cycle is presented which includes the effects of anthropogenic &CO\sb2& emissions &(CO\sb2& produced from fossil fuel combustion, biomass burning, and deforestation) on the global carbon cycle. The model is validated against measured atmospheric &CO\sb2& concentrations. Future levels of atmospheric &CO\sb2& are then predicted for the following scenarios: (1) Business as Usual (BaU) for the period 1990-2000; (2) Same as (1), but with no biomass burning; (3) Same as (1), but with no fossil fuel combustion; (4) Same as (1), but with a doubled atmospheric &CO\sb2& concentration and a 2 K warmer surface temperature …
Constrained Least-Squares Digital Image Restoration, Rajeeb Hazra
Constrained Least-Squares Digital Image Restoration, Rajeeb Hazra
Dissertations, Theses, and Masters Projects
The design of a digital image restoration filter must address four concerns: the completeness of the underlying imaging system model, the validity of the restoration metric used to derive the filter, the computational efficiency of the algorithm for computing the filter values and the ability to apply the filter in the spatial domain. Consistent with these four concerns, this dissertation presents a constrained least-squares (CLS) restoration filter for digital image restoration. The CLS restoration filter is based on a comprehensive, continuous-input/discrete- processing/continuous-output (c/d/c) imaging system model that accounts for acquisition blur, spatial sampling, additive noise and imperfect image reconstruction. The …
Spawning And Ecology Of Early Life Stages Of Black Drum, Pogonias Cormis, In Lower Chesapeake Bay, Louis Broaddus Daniel Iii
Spawning And Ecology Of Early Life Stages Of Black Drum, Pogonias Cormis, In Lower Chesapeake Bay, Louis Broaddus Daniel Iii
Dissertations, Theses, and Masters Projects
During spring 1990 and 1991, ichthyoplankton surveys were conducted in lower Chesapeake Bay to estimate seasonal egg production, population biomass and the impact of predation by gelatinous zooplankton on early life stages of black drum, Pogonias cromis. Rearing experiments indicated that at least three species of sciaenid (silver perch, Bairdiella chrysoura; weakfish, Cynoscion regalis and P. cromis) were spawning in the survey area during both years. Specific identification of eggs based on previously published ranges of outside egg diameter (OED) were not reliable due to considerable overlap in diameter distributions. Analysis of weekly OED frequency revealed the presence of three …
Nutrition And Feeding In Striped Bass Morone Saxatilis Larvae: Lipid And Fatty Acid Requirements And Microencapsulated Diets, Sureyya Ozkizilcik
Nutrition And Feeding In Striped Bass Morone Saxatilis Larvae: Lipid And Fatty Acid Requirements And Microencapsulated Diets, Sureyya Ozkizilcik
Dissertations, Theses, and Masters Projects
There has been a growing interest in the commercial aquaculture of striped bass, Morone saxatilis. Little is known, however, about the nutritional requirements and feeding physiology of striped bass larvae. The objectives of this study were (a) to evaluate the efficiency of the live food enrichment techniques in studying the nutritional requirements for polyunsaturated fatty acids (PUFA), phospholipids and free amino acids, (b) to determine the ontogenetic changes of lipolytic enzymes, and (c) to develop a microencapsulated diet for striped bass larvae as full or partial replacement of live food. Three enrichment techniques, namely, microencapsulated fish oil, yeast/fish oil emulsion …
Error Analysis In Tidal Wetland Inventory Change Detection: Comparison Of Historical Mapped Wetlands Of The Achilles Quadrangle Between 1976 To 1989, Stacy A. C. Nelson
Error Analysis In Tidal Wetland Inventory Change Detection: Comparison Of Historical Mapped Wetlands Of The Achilles Quadrangle Between 1976 To 1989, Stacy A. C. Nelson
Dissertations, Theses, and Masters Projects
No abstract provided.
The Geomorphology And Shallow Structure Of The Northeastern New Jersey Continental Slope, Nicole D. Scott
The Geomorphology And Shallow Structure Of The Northeastern New Jersey Continental Slope, Nicole D. Scott
Dissertations, Theses, and Masters Projects
No abstract provided.
Filtration Of Oysters In Patches: Effects Of Water Flow And Seston Composition, Deborah Armitage Harsh
Filtration Of Oysters In Patches: Effects Of Water Flow And Seston Composition, Deborah Armitage Harsh
Dissertations, Theses, and Masters Projects
No abstract provided.
High-Resolution Seismic Stratigraphy Of The Ganges-Brahmaputra River System: Subaqueous Deltaic Progradation On The Bengal Shelf, Beth Michele Levy
High-Resolution Seismic Stratigraphy Of The Ganges-Brahmaputra River System: Subaqueous Deltaic Progradation On The Bengal Shelf, Beth Michele Levy
Dissertations, Theses, and Masters Projects
No abstract provided.
An Analysis Of Wetland Total Phosphorus Retention And Watershed Structure, Megan K. Greiner
An Analysis Of Wetland Total Phosphorus Retention And Watershed Structure, Megan K. Greiner
Dissertations, Theses, and Masters Projects
No abstract provided.
Osmotic Tolerance And Volume Regulation In Cultured Cells Of The Oyster Pathogen Perkinsus Marinus, Caroline L. O'Farrell
Osmotic Tolerance And Volume Regulation In Cultured Cells Of The Oyster Pathogen Perkinsus Marinus, Caroline L. O'Farrell
Dissertations, Theses, and Masters Projects
No abstract provided.
Wave Diffraction And Refraction Problem And A Block-Wise Band Matrix Solver, Changqing Li
Wave Diffraction And Refraction Problem And A Block-Wise Band Matrix Solver, Changqing Li
Dissertations, Theses, and Masters Projects
No abstract provided.
An Electronic Storage And Access System For Special Education Legislation, Courtney Siler Frantz
An Electronic Storage And Access System For Special Education Legislation, Courtney Siler Frantz
Dissertations, Theses, and Masters Projects
In the field of education, instructional leaders must know the regulations governing the assessment, curriculum, and instruction of all students. An area of special concern is the regulations governing programs for students with disabilities. Although the average population of students with disabilities may represent less than 10% of the total student body, the school administrator is responsible for maintaining access to the most current regulations, for accurately interpreting, and effectively implementing federal and state mandates to ensure that the due process rights of the students with disabilities are upheld. Yet the laws and regulations governing special education programs are continually …
First Principles Linear Response Calculations Of Lattice Dynamics, Cheng-Zhang Wang
First Principles Linear Response Calculations Of Lattice Dynamics, Cheng-Zhang Wang
Dissertations, Theses, and Masters Projects
First principles calculations, using the density-functional theory and particularly the local density approximation (LDA), have achieved remarkable success in studying the properties of solid state systems. Although the basic results of these calculations are the electronic structures (eigenvalues, eigenfunctions, etc.) and the total energy of ground state, many other related physical properties can be deduced from them by investigating their response under external perturbations. Using the linear response method with linearized-augmented-plane-wave (LAPW) basis, we have calculated lattice dynamical properties of important semiconductors CuCl, SiC and ferroelectric KNbO{dollar}\sb3.{dollar} CuCl is known to exhibit large anharmonic effects and possibly a complicated multi-well …
Search For Metastability Of 2s Muonic Neon, Bernard Wilhelm Bach
Search For Metastability Of 2s Muonic Neon, Bernard Wilhelm Bach
Dissertations, Theses, and Masters Projects
An experiment was performed at the Paul Scherrer Institut (PSI) to establish the conditions for the metastability of the 2S-state of muonic neon. The muonic atoms were formed by stopping negative muons in the neon-filled target chamber of the PSI cyclotron trap. A pair of intrinsic germanium detectors were used in coincidence to search for the two photon decay of the 2S-state. Both energy and time information from two photon events were written to disk for off-line analysis. Data were accumulated for neon pressures of 40 and 400 Torr. The data were then searched for evidence of two photon transitions …
The Synthesis, Characterization, And Application Of Ether-Containing Polymides, Catharine Croall Fay
The Synthesis, Characterization, And Application Of Ether-Containing Polymides, Catharine Croall Fay
Dissertations, Theses, and Masters Projects
Polyimides are a family of heterocyclic polymers that have received extensive evaluation as adhesives, fibers, films, moldings, composite matrices, insulators, coatings, membranes, and resists. their outstanding thermal stability, excellent mechanical and electrical properties, and chemical resistance make them attractive for many applications.;This research developed ether-containing polyimides for three applications: liquid crystalline polyimides as processing aids, polyimides for microelectronic applications, and polyimides for harsh environments. The approach consisted of three primary activities: (1) developed novel diether dianhydrides for polyimide fabrication, (2) designed, characterized, and evaluated polyimide architectures based on the material application requirements, and (3) provided extensive structure-property relationships utilizing a …
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Dissertations, Theses, and Masters Projects
The resuspension behavior of natural estuarine sediments was studied using the VIMS Sea Carousel, a benthic annular flume. The bed shear stresses produced by the flume were measured by a hot-film sensor mounted flush on the bottom of a laboratory version of the Carousel under a clear-water and flat-bottom condition. Measurements showed a reasonably uniform bed shear stress across the channel and agreed with the relationship &\tau\sb{lcub}\rm b{rcub}=0.011\Omega\sp{lcub}1.69{rcub},& where &\Omega& = ring speed (rpm) and &\tau\sb{lcub}\rm b{rcub}& = spatially-averaged bed shear stress (N/m&\sp2&), predicted from a previous numerical study. Thus, the &\tau\sb{lcub}\rm b{rcub}& was used as a bed shear stress …
Reproductive And Feeding Biology Of Selected Syngnathids (Pisces: Teleostei) Of The Western Atlantic, Rogerio Luiz Teixeira
Reproductive And Feeding Biology Of Selected Syngnathids (Pisces: Teleostei) Of The Western Atlantic, Rogerio Luiz Teixeira
Dissertations, Theses, and Masters Projects
The reproductive and feeding biology of five syngnathid species of the western Atlantic were studied: the pipefishes Syngnathus fuscus, S. floridae, the lined seahorse Hippocampus erectus of Chesapeake Bay; and the pipefishes S. folletti and Oostethus lineatus, from southern and southeast Brazil, respectively. Male syngnathids incubate eggs received from females in a ventral brood pouch, females do not play any additional role in parental care after mating. This natural sex role reversal is a unique characteristic that all male syngnathids have. In other fishes, parental care is usually a female prerogative. Most pipefishes are polygamous, while seahorses are monogamous. Syngnathus …