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Protein And Endotoxin Interactions And Endotoxin Removal From Protein Solutions, Liping Li
Protein And Endotoxin Interactions And Endotoxin Removal From Protein Solutions, Liping Li
Dissertations
The investigation objectives of this study include: endotoxin disaggregation by proteins; protein concentration effect on protein-endotoxin binding and endotoxin removal; size exclusion high performance liquid chromatography (SE-HPLC) studies on endotoxin dissociation by bovin serum albumin (BSA); use of Ca+2 to re-aggregate endotoxin in hemoglobin solutions and the subsequent removal of endotoxin by ultrafiltration; quantitative determination of Ca+2 effects on endotoxin removal and protein yield in a two-stage ultrafiltration.
It is known that some proteins can disaggregate endotoxins and form complexes with lipopolysaccharides (LPS). It is also known that Ca can act as "bridges" to aggregate LPS in aqueous …
Cadmium, Chromium And Lead In Environmental Samples : Speciation And Determination, Hsing-Hui Yu
Cadmium, Chromium And Lead In Environmental Samples : Speciation And Determination, Hsing-Hui Yu
Dissertations
Heavy metals are important contaminants in many environmental media. This work focuses on the improvement of current methods for water and sediment analysis for three metals, cadmium, chromium and lead. Batch ion exchange was used for water speciation and a microwave assisted sequential extraction scheme was developed for sediment characterization. The developed methods were applied to a group of environmental samples.
The exchangeable species of these metals in water were preconcentrated on ion exchange resins. These include the bioavailable free ions and weakly complexed ions. Metals sorbed on particles and strongly complexed ions, less bioavailable, were eliminated. The method was …
Applications Of A Microtrap For On-Line Monitoring Of Volatile Organics, Chaohua Feng
Applications Of A Microtrap For On-Line Monitoring Of Volatile Organics, Chaohua Feng
Dissertations
Microtrap is made by packing a narrow metal tubing with adsorbents. The advantage of a microtrap is that it can be heated and cooled in the order of seconds. It has been used previously as a concentration cum injection device for on-line gas chromatography and also monitoring non-methane organic carbon in air emissions. In this research breakthrough and desorption characteristics of the microtrap were studied. A two-stage microtrap system was developed to reduce breakthrough while making sharp injection for GC separation. Microtrap was also used as a concentrator cum injector in on-line mass spectrometry. Finally, a microtrap based, continuous non-methane …
Development Of Membrane Extraction Systems For Measuring Trace Level Organic Compounds In Water, Xuemei Guo
Development Of Membrane Extraction Systems For Measuring Trace Level Organic Compounds In Water, Xuemei Guo
Dissertations
The presence of volatile organic compounds (VOCs) in ground and surface water resources poses a threat to public health. The measurement of these trace level contaminants in water is of significant importance. Conventional methods for analysis of trace volatile organic compounds in water include purge and trap, head space analysis, and solid phase microextraction (SPME). While these are excellent laboratory techniques, none of them can be used for continuous, on-line monitoring of water streams. Membrane separation of organic compounds from water provides an exciting possibility for on-line extraction and analysis. In previous investigations, water continuously flowed on the feed side …
Oxidation Of Dimethyl-Ether And Ethylene In The Atmosphere And Combustion Environment And Thermodynamic Studies On Hydrofluorocarbons Using Ab Initio Calculation Methods, Takahiro Yamada
Dissertations
Reaction pathways and kinetics are analyzed on CH3OC·H2 unimolecular decay and on the complete CH3OC·H2 + O2 reaction system using thermodynamic properties (ΔHf°298, S°298, and C(T) 300≤T/K≤1500) derived by two ab initio calculation methods, CBS-q and G2. These are used to determine thermodynamic properties of reactants, intermediate radicals and transition state (TS) compounds. Quantum Rice-Ramsperger-Kassel (QRRK) analysis is used to calculate energy dependent rate constants, k(E), and master equation is used to account for collisional stabilization. Comparison of calculated fall-off with experiment indicates that the CBS-q and …