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An Investigation Of Plume Rise From Titan Iv Rocket Launches, Joseph D. Brands
An Investigation Of Plume Rise From Titan Iv Rocket Launches, Joseph D. Brands
Theses and Dissertations
Space launches at Cape Canaveral Air Station (CCAS) and Vandenberg Air Force Base (vAFB) produce exhaust ground clouds from the solid rocket boosters and liquid hypergolic fuels containing several toxic substances. In order to estimate the health effects that would be imposed upon the public by scheduled launches, range safety officials rely on the Rocket Exhaust Effluent Diffusion Model to predict ground level concentrations of these substances. A drawback to the REEDM is its underprediction of the initial ground clouds stabilization height. This underprediction causes an overprediction of the ground level toxic substance concentrations. This thesis focused on increasing the …
A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood
A System Dynamics Model Of The Bioavailability Of Metals In Constructed Wetland Sediment, Timothy S. Wood
Theses and Dissertations
Constructed wetlands used for storm water treatment accumulate metals primarily in their sediment. This sediment has the potential to produce toxic effects in benthic organisms at some period in time. Bioavailability of metals in sediment is directly linked to pore water metal activity. The mechanisms that influence pore water metal activity are included in physical, chemical, and biological processes. A system dynamics model was developed to represent these processes and the major influences affecting pore water metal activity in a treatment wetland receiving storm water influent. The model structure and behavior was tested and validated using several system dynamics validation …
A Modeling Study For The Implementation Of In Situ Cometabolic Bioremediation Of Trichloroethylene-Contaminated Groundwater, John A. Christ
A Modeling Study For The Implementation Of In Situ Cometabolic Bioremediation Of Trichloroethylene-Contaminated Groundwater, John A. Christ
Theses and Dissertations
The limitations of conventional groundwater remediation technologies have led to the development of innovative technologies which may achieve national hazardous waste site remediation goals. Before an innovative technology can be implemented in the field, remedial project managers, regulators and other stakeholders require adequate modeling tools to help assess the applicability of the technology at a particular site. This modeling study investigates how an innovative technology, in situ cometabolic bioremediation, might be implemented to remediate a TCE-contaminated site, under different site conditions. A steady-state model is developed which couples an analytical expression to simulate the effect of flow between multiple pumping …
Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney
Mobilization Of Trace Elements In Aquifers By Biodegradation Of Hydrocarbon Contaminants, Scott L. Kearney
Theses and Dissertations
This study had two objectives: (1) to determine the extent of metal mobility within petroleum-contaminated aquifers, (2) to determine if biodegradation of petroleum hydrocarbons can explain metal mobility. The approach reviewed analytical results from 2305 groundwater sampling events, taken from 958 wells, located at 136 sites found at 53 Air Force installations. The study showed that high levels of metals are present at petroleum hydrocarbon sites where metals would not generally be expected. Of the metals with drinking water maximum contaminant levels (MCLs), mercury and silver were detected the least frequently. Barium and copper were detected at the sites, but …
The Fate And Transport Of Airborne Jp-4 And Jp-8 Aerosol During Cold Startup, Bradford Eugene Buckman
The Fate And Transport Of Airborne Jp-4 And Jp-8 Aerosol During Cold Startup, Bradford Eugene Buckman
Theses and Dissertations
During cold startup (engine warm-up) procedures at northern tier bases, fuel aerosol (JP-4 and JP-8) is emitted before complete combustion of the fuel occurs. The time necessary for complete combustion to occur may be as long as 10 minutes. Hence, during these first few minutes, aerosol is emitted at relatively high concentrations. This research investigates the principle behavior of the emitted aerosol: advection, dispersion, evaporation, and settling. Using previous work in fuel jettisoning and evaporation as a foundation, this thesis investigates the physical factors affecting the airborne concentration of fuel aerosol at different times, the amount of fuel aerosol reaching …
Modeling The Uptake And Transpiration Of Tce Using Phreatophytic Trees, Douglas P. Wise
Modeling The Uptake And Transpiration Of Tce Using Phreatophytic Trees, Douglas P. Wise
Theses and Dissertations
Phytoremediation is a recent addition to the numerous methods used today to remediate ground water contaminants. It is proving more effective and efficient compared to existing remediation techniques. The use of phreatophytes, or water seeking trees, has great potential for phytoremediation. These trees are fast growing, long lived, grow their roots down to the ground water table, transpire large amounts of water, and are proven to actively remove contaminants from the soil horizon. The purpose of this research is to develop quantitative concepts for understanding the dynamics of TCE uptake and transpiration by phreatophytic trees over a short rotation woody …
Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan
Modeling Uptake And Translocation Of Lead (Pb) In Maize For The Purposes Of Phytoextraction, Mark A. Brennan
Theses and Dissertations
Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. This technology has the potential to decrease the costs of remediating contaminated sites by several orders of magnitude compared to traditional technologies. To effectively implement this technology requires an understanding of the plant processes that control uptake and translocation of metals from the soil. Currently these processes are poorly understood, and especially so for Pb. The purpose of this thesis was to gain insights concerning the plant mechanisms that control uptake and translocation of Pb and how these mechanisms interact to control levels of Pb accumulation …
A Comparison Of Movements And Burrow Usage Between Indigenous And Relocated Gopher Tortoises (Gopherus Polyphemus) In A Fall Line Sandhills Community, Dorinda Morpeth
A Comparison Of Movements And Burrow Usage Between Indigenous And Relocated Gopher Tortoises (Gopherus Polyphemus) In A Fall Line Sandhills Community, Dorinda Morpeth
Theses and Dissertations
The movements and burrow use of twenty (ten relocated and ten indigenous to the relocation site) adult gopher tortoises {Gopherus polyphemus) were followed during the late spring, summer and early autumn in Talbot County, Georgia. The objectives of this study were to determine whether relocated gopher tortoises developed fidelity to a relocation site, and whether indigenous tortoises reacted adversely to relocated tortoises released in their proximity. Ten tortoises in the right-of-way of a highway construction project were captured, fitted with transmitters, and relocated to a 336 hectare tract of land, 3.2 km east of Geneva, Talbot, County, Georgia. Concurrently, ten …
A Descriptive Survey Of Freshwater Unionidae Bivalves In Five Creeks Located In West Central Georgia, Rufus Carson Stringfellow
A Descriptive Survey Of Freshwater Unionidae Bivalves In Five Creeks Located In West Central Georgia, Rufus Carson Stringfellow
Theses and Dissertations
A descriptive survey of the West Georgia, Chattahoochee River drainage unionid bivalve fauna inhabiting Mountain Oak, Mulberry, Standing Boy, and Upatoi Creeks has been completed. The survey is intended to determine whether Unionidae populations remain extant in this portion of the Chattahoochee River drainage, and to estimate the abundance and distribution of species encountered. Accessibility sampling was employed; sites selected to be surveyed were usually located at a road bridge or some landmark easily identifiable for geographical positioning. Collecting methods included the use of a small rake in sandy or silty substrate, visual detection of siphons or trails in the …
Response Surface Methodology: An Analytical Method For Locating Migrated Contaminant Sources, Orlando J. Dona Jr.
Response Surface Methodology: An Analytical Method For Locating Migrated Contaminant Sources, Orlando J. Dona Jr.
Theses and Dissertations
The use and storage of hazardous chemicals at U.S. military facilities often adversely affect the groundwater when contaminants infiltrate the subsurface as a result of leaks and accidental spills. These contaminants, if not located and remediated in a relatively short time, may move and settle unpredictably, essentially creating a source some distance from the original leak or spill. An example of this phenomenon is found with migrating dense nonaqueous phase liquid (DNAPL) contaminants. Although various methods for estimating the present day locations of these migrated contaminants are in use, accurately pinpointing the source of contaminants remains a difficult problem in …