No description available.

The aim of this work was to extend the theory of Everett and Cruickshank, for the determination of activity coefficients at infinite dilution, Y 13 (where 1 refers to the solute and 3 to the solvent), to accommodate solvents of moderate volatility, using the gas liquid chromatography (GLC) method. A novel data treatment procedure is introduced to account for the loss of solvent off the column, during the experiment. The method also allows us to determine the vapour pressure of the solvent. No auxiliary equipment is required, and the method does not employ the use of a presaturator. Further, the effect of a polar involatile solute is examined using various types of solutes. The activity coefficient was found to be independent of column packing and flowrate. Considering the volatile solvent, the systems investigated by the GLC method were straight chain hydrocarbons, (n-pentane, n-hexane and n-heptane), cyclic hydrocarbons (cyclopentane, and cyclohexane) and an aromatic compound, benzene. The systems were investigated at 2 temperatures, 280.15 K and 298.15 K. The results indicate a clear dependence of the activity coefficient on temperature. For the polar nonvolatile solvent, sulfolane (tetrahydrothiophene, 1,1 dioxane) was used. The systems studied were sulfolane + n-pentane, n-hexane, n-heptane, cyclopentane, cyclohexane, benzene, tetrahydrofuran, and tetrahydropyran. The systems were studied at one temperature, 303.15 K, due to the low melting point of sulfolane i.e. 301.60 K. Part of this study into the thermodynamics of solutions'\vas conducted at the Technical University of Warsaw, where the equilibria of sulfolane was studied using· two techniques, a dynamic solid-liquid equilibrium method (SLE), and an ebulliometriGI vapor-liquid method (VLE) . The main purpose of this was to apply solution theories to this data in order to predict the.activity coefficient at infinite dilution for the sulfolane mixtures. The systems measured using solid liquid equilibrium are sulfolane + tetrahydrofuran, or, 1,4-dioxane, or, I-heptyne, or, 1, 1, l,-trichloroethane, or, benzene, and cyclohexane. The results of these measurements were then described using various solution theories, and· new interaction parameters obtained. The vapour liquid equilibrium systems measured were sulfolane + I-heptyne, or, tetrahyrdofuran, or, 1,1, I-trichloroethane, and tetrachloromethane. Here as in SLE the results were described using solution theories. The results of both the VLE and SLE measurements were used in a multiple optimization procedure to produce new parameters for the interaction of sulfolane with various groups, using two group contribution method, DISQUAC and modified UNIFAC. The predicted activity coefficients compare well with the measured values using GLC. / Thesis (Ph.D.)-University of Natal, 1995.

The ability to effectively analyze particulate matter (PM2.5) in air is becoming increasingly pertinent. Allen Goldstein of the University of California in Berkeley is studying the semi-volatile fraction of organic compounds in PM2.5 through the use of the thermal desorption aerosol gas chromatograph (TAG) system. However, as conventional GC does not provide adequate separation power, the development of comprehensive two-dimensional gas chromatography (GC × GC) was required. GC × GC works more effectively by utilizing a modulator that periodically traps and focuses analytes from a primary column onto a secondary column. This allows for the primary and secondary columns to separate the analytes based on two different properties. This report focuses on the continuing study and enhancement of a modulator designed by Ognjen Panić during his Masters project. Improving and testing the robustness of this dual stage modulator was originally the focus of this project. However, this study led to the development of a single stage modulator. In addition to that, the effect of modulator characteristics such as length of the restriction, total length of the modulator and wall thickness on the modulator performance were studied. A robustness test of the single stage modulator was also completed. Experiments conducted tested the characteristics of the new modulator to ensure it performed effectively and would satisfy the requirements of the TAG system. A study comparing the sensitivity of conventional gas chromatography and GC × GC was also preformed. The sensitivity of GC × GC was on average an order of magnitude better than that of 1D GC.

In Australia, the 0.22 calibre ammunition is the most encountered ammunition type found at a crime scene [1]. Previous analysis of gun shot residue (GSR) and unfired propellant has involved studying the inorganic constituents by Scanning Electron Microscopy or similar technique. However, due to the heavy metal build up that comes with some ammunition types, manufacturing companies are now making propellant that is safer to use. Therefore, it has become appropriate to study and analyse unfired propellant by other means. One such technique is unfired propellant analysis by gas chromatography – mass spectrometry (GC-MS). This technique focuses on the organic constituent make up of the propellant paying particular attention to diphenylamine, ethyl centralite and dibutyl phthalate. It was proposed that different batches of ammunition could be discriminated or matched to each other by using this technique. However, since the main constituents of unfired propellant are highly reactive, it was not possible to accomplish batch determination of ammunition. However, by improving extraction techniques and by removing oxygen (a catalyst for the degradation of diphenylamine) a superior method was established to help in the analysis of unfired propellant. Furthermore, it was shown that whilst differentiating batches of the same ammunition was not possible, the improved methods have helped identify different types of the same brand of ammunition. With the aid of future studies to fully explore this avenue, the analysis of unfired propellant could one day become an integral part of forensic science.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 87 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 72-73).

Thesis (M.S.)--University of North Carolina Wilmington, 2007. / Includes bibliographical references (leaves: 67-68)

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Thesis (M. App. Sc.)--Carleton University, 2002. / Includes bibliographical references (p. 157-179). Also available in electronic format on the Internet.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 11, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering, [Department of] Chemical & Materials Engineering, University of Alberta. Includes bibliographical references.

Thesis (Ph.D.)--Ohio University, March, 2010. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until April 1, 2012. Includes bibliographical references.