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Full-Text Articles in Physical Sciences and Mathematics
Synthesis And Characterization Of Silicon Dioxide Thin Films By Plasma Enhances Chemical Vapor Deposition From Diethylsilane And Nitrous Oxide, Lan Chen
Theses
This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by plasma enhanced chemical vapor deposition(PECVD), using diethylsilane (DES) as a precursor and nitrous oxide (N2O) as the oxidant. The process parameters, such as temperature, pressure and reactant gas composition have been systematically varied and their effects on the film growth rate and properties were investigated. The growth rate was found to be inversely proportional to the temperature in the examined range of 100-300°C. It increased with increasing N2O/DES flow rate ratio as the total flow rate increased …
Factors Effecting Calcification Of Bioprosthetic Heart Valves, Sumei Yu
Factors Effecting Calcification Of Bioprosthetic Heart Valves, Sumei Yu
Theses
Calcification is the most frequent cause of clinical dysfunction of glutaraldehyde treated bioprosthetic heart valves. In this study, we compared calcification of bioprostheses of the No-ReactTM and the conventional glutaraldehyde treated pericardium by both in-vivo and in-vitro methods, and to further delineate the role of the host's inflammatory response in implant degeneration.
In the in-vitro study, the two types of pericardial samples were placed in individual polystyrene tubes containing physiological concentrations of calcium and phosphate and incubated for 21 days at 37°C. In the in-vivo study, the two types of pericardial samples were implanted subcutaneously in rats and subsequently retrieved …
Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami
Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami
Theses
Removal of trichloroethylene, monochlorobenzene and 1,3 dichlorobenzene from water by air stripping and solvent sublation into an organic phase was investigated. The sublation solvents used were paraffin oil and decyl alcohol. The rate of removal from water by solvent sublation and air stripping was highest for trichloroethylene, followed by chlorobenzene and finally 1,3 dichlorobenzene. For the three compounds, solvent sublation had the greatest advantage over air stripping in the reduction of emission of the compounds to the atmosphere. For the three compounds, the removal was enhanced at higher flowrate in both air stripping and solvent sublation. For the removal of …
The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly
The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly
Theses
This research was initiated to examine the Diarrhetic Shellfish Poisoning (DSP) toxin profiles in mussels (Mytilus edulis) in south-west Ireland. Extensive sampling and testing of shellfish was conducted during the toxic periods of 1991 to 1994. This was the most comprehensive study ever undertaken of toxin profiles in shellfish from a single cultivation area.
A new toxin named dinophysistoxin-2 (DTX-2), which is an isomer of okadaic acid (OA), was the major toxin during prolonged DSP episodes. This toxicity in shellfish occuired soon after high cell counts of Dinophysis acuta were observed. As well as seasonal variability in toxin levels, substantial …
Volatilization Of Contaminants From Wastewater, Shaoyan Wu
Volatilization Of Contaminants From Wastewater, Shaoyan Wu
Theses
Emission of volatile organic compounds (VOCs) from many industrial wastewater treatment facilities are a major source of air pollution, and getting much attention from EPA. In order to determine "Best Available Control Technology" and "Lowest Achievable Emission Rate" for controlling emissions of VOCs from industrial wastewater, the accurate estimation of VOCs emission rate and realistic modeling of contaminant volatilization are required.
In this research, the volatilization of three compounds (Toluene, Xylene, and Aniline) were studied under varying aeration, stirring, and quiescent scenarios. The concentrations of contaminant were analyzed by HPLC. Experimental rate constants were obtained by using the first order …