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Articles 1 - 9 of 9
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.
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 …
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 Study Of The Histozoic Oyster Parasite, Perkinsus Marinus: I. Disease Processes In American Oysters (Crassostrea Virginica). Ii. Biochemistry Of Perkinsus Marinus, Aswani K. Volety
Dissertations, Theses, and Masters Projects
Numerous studies have investigated the disease processes of Perkinsus marinus in the oyster, Crassostrea virginica. However, the transmission dynamics and factors affecting P. marinus infection are still unclear. The objectives of this study were to investigate: (1) the principal and most effective lifestage of P. marinus, (2) the synergistic effects of temperature, salinity and P. marinus dose on disease prevalence, (3) suppression of host reactive oxygen intermediates by P. marinus, (4) the localization of acid phosphatase in the parasite, (5) the effects of temperature and salinity on acid phosphatase secretion, and (6) the P. marinus lipid and fatty acid composition. …
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.
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.
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.
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 …
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 …