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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

The Analysis of Plasmid Conformers using Dynamic Size-Sieving Capillary Electrophoresis

Nevins, Stacey 01 January 1998 (has links)
No description available.

Novel Derivatizing Agents for the Determination of Methylmercury by Gas Chromatography using Electron Capture Detection

Irwin, Crystal Marie 01 January 2006 (has links)
No description available.

Interpretation of GC-MS data by reverse search and relative retention indices

Hein, Christopher 01 January 1981 (has links)
No description available.

The Development and Application of a Helium Discharge Detector for Gas Chromatography

Ware, Margaret LaVerne 01 January 1988 (has links)
No description available.

Automated Data Acquisition for Analysis of Fly Ash by Graphite Furnace Atomic Absorption Spectrophotometry

Dowds, Eileen 01 January 1989 (has links)
No description available.

Evaluation of Scavenger Gases in a Helium Discharge Detector

Poteat, Sandra Lynn 01 January 1991 (has links)
No description available.

A Helium Discharge Detector for the Determination of Organosulfur and Phosphorus Compounds

Tieman, Tamara L. 01 January 1992 (has links)
No description available.

Pulse-Laser Infrared Photothermal Spectrometry of Condensed-Phase Aerosols Based on Photothermal Deflection Spectroscopy

Dada, Oluwatosin Olubunmi 01 December 2008 (has links)
The research reported in this dissertation is aimed at development of photothermal deflection detector that is consistent with constraints imposed by aerosols sampling and analysis. The main objectives of this project are: 1) the design and evaluation of initial apparatus prototypes and 2) a test of the prototype apparatus with surrogate substances using conventional mid-infrared gas lasers. Experimental evaluation of reduced size photothermal apparatus is first performed with gaseous samples. Analysis of trichlorofluoromethane (CFC-11) and ethanol vapors is performed with both conventional large apparatus and the prototype small apparatus. Comparison studies in terms of photothermal signal from both apparatuses are carried out to examine how apparatus downscaling affects photothermal signal. The main result indicates that the small apparatus performs about the same as the conventional laboratory-size apparatus. For better understanding of heat transport from aerosols collect on a flat substrate and its surrounding media, a numerical methodology based on finite element analysis is used to investigate the heat transfer between aerosol, substrate, and air. The numerical modeling is extended to prediction of photothermal signals from laser excited optical beam deflection due to temperature gradient inside the air above aerosols. The modeling results help to understand how aerosol properties such as size, shape, thermo-optical properties, and particles arrangement affect photothermal signal. The model is also used to investigate the influence of substrate properties on photothermal signal. A photothermal deflection apparatus is then used to examine the potential of mid-infrared photothermal spectroscopy for aerosol analysis. Laboratory-generated ammonium nitrate aerosols are deposited on germanium substrate by using Micro-Orifice Uniform Deposits Impactor (MOUDI). Photothermal spectroscopy, based on optical beam deflection (mirage effect), is used to analyze the collected aerosols. The measurements are carried out in terms of aerosol number concentration and aerosol mass concentration. Based on standard 30 minutes sampling time and 30 L/min flow rate, the limit of detection obtained for our instrument are 18 particles, equivalence of 0.2 μg m-3 mass concentrations for 3 μm particles diameter) for aerosol number concentration measurement and 0.65 μg m-3 for aerosol mass concentration measurement. Out of curiosity on whether standard materials could be used to calibrate a photothermal lens apparatus without having to make up liquid samples, it was thought that colored glass filters would serve as such standards. Photothermal lens measurements and finite element modeling are used to examine the physical changes taking place in optical filter glasses. Colored-glass and neutral density filters are found to have a strong positive temperature-dependent refractive index change.

Analysis of Mercury Coordination Environments of Tridentate and Tetradentate Nitrogen Based Ligands by NMR Spectroscopy and X-Ray Crystallography

Freer, Rachel E. 01 January 1997 (has links)
No description available.

Analysis of Mercury Coordination Environments of Tridentate and Tetradentate Imidazole Based Ligands by X-Ray Crystallography and NMR Spectroscopy

Murphy, Geoffrey 01 January 1999 (has links)
No description available.

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