Gas chromatography (GC) is a technique that includes all chromatographic processes in which a substance to be analyzed is in the gaseous state or is converted into such a state. Miniaturized GCs are in high demand due to their portability, ability to operate in the field, low power requirements and low material cost. The focus of this thesis is on the development, testing and applications of portable analytical instruments, specifically miniature gas chromatographs. In the first chapter, two portable gas chromatograph prototypes are described; including a miniature GC and an auto sampling GC. The second chapter describes student experiment development that incorporates mini GCs into the academic chemistry curriculum and focuses on teaching principles of chromatography or use a gas chromatograph as a tool. The third chapter focuses on development, testing and application of a portable auto sampling prototype GC to aid in the production of biofuels.

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We present the speedup from a novel parallel implementation of the multicanonical method on the example of a lattice gas in two and three dimensions. In this approach, all cores perform independent equilibrium runs with identical weights, collecting their sampled histograms after each iteration in order to estimate consecutive weights. The weights are then redistributed to all cores. These steps are repeated until the weights are converged. This procedure benefits from a minimum of communication while distributing the necessary amount of statistics efficiently. Using this method allows us to study a broad temperature range for a variety of large and complex systems. Here, a gas is modeled as particles on the lattice, which interact only with their nearest neighbors. For a fixed density this model is equivalent to the Ising model with fixed magnetization. We compare our results to an analytic prediction for equilibrium droplet formation, confirming that a single macroscopic droplet forms only above a critical density.

No description available.

The concept which led to the establishment of the research in natural gas hydrate production, was born by Dr. Robert Amin (currently Professor of Petroleum Engineering at Curtin University and Chair of the Woodside Research Foundation) and Alan Jackson of Woodside Energy. The intended research in this field is to establish the viability of utilizing a synthesised natural gas hydrate as a means to allow a cheaper form of transportation of natural gas from the wellhead to the customer in direct competition with liquefied natural gas (LNG). Natural gas exists in ice-like formations called hydrates found on or under sea-beds and under permafrost. Hydrates trap methane molecules inside a cage of frozen water, where the amount of hydrates trapped is dependent on surrounding formation pressure. The amount of natural gas trapped in hydrates is largely unknown, but it is very large. A number of scientists believe that hydrates contain more than twice as much energy as all the world's coal, oil, and natural gas combined, hence making it a viable option of fuel in the 21st century, in a world constantly seeking cleaner sources of energy. The feasibility of production of natural gas hydrates on offshore installations and onshore facilities makes this development a viable option. As such this technology requires detailed research and development in a laboratory environment coupled with a pilot plant construction for commercial operation. Current estimates for onshore based facilities for the production of hydrates show a cost reduction of approximately 25% compared with LNG plants of the same energy capacity. / There are two major issues which require detailed research and development in order to progress this technology. First is the enhancement of the hydrates production by the use of other additives, and second, the continuous production at near atmospheric pressures. Other research related to transport methodology and re-gasification will be essential for the overall success of this technology, however, this work is outside the scope of this research.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Tulsa, 1975. / Bibliography: l. 45-48.

Thesis (Ph.D.). / Title from title page of PDF (viewed 2008/01/30). Written for the Dept. of Mining, Metals and Materials Engineering. Includes bibliographical references.

Thesis (M.Eng (Mechanical and Aeronautical Engineering)) -- University of Pretoria, 2007. / Includes bibliographical references (leaves 120-126)