No description available.

Natural-synthetic hydrid biomaterials have been isolated from the growth of Alcaligenes latus and Pseudomonas oleovorans in the presence of diethylene glycol (DEG). A. latus could cometabolise DEG with 10 g/L glucose, while DEG was consumed by P. oleovorans with 20 mM sodium octanoate or octanoic acid. The presence of DEG in bioprocessing systems for the production of short chain length (scl-) and medium chain length (mcl-) PHAs consequently lowered cell viability and PHA yield. Cell morphology was slightly changed, but the PHA inclusion bodies apparently were not. DEG affected the composition of the mclPHA which was confirmed to be polyhydroxyoctanoate (PHO) with a significant increase in the C8 component. Gas chromatography-mass spectrometry (GC-MS) was used to quantitatively monitor DEG in the system and revealed its cellular adsorption. Intracellularly, the DEG significantly decreased the molar weight of the mclPHA and sclPHA. P1PH NMR, 2-D COSY and HSQC spectra confirmed that the polymer samples consisted of PHA chains terminated by DEG. Similar to the cultivation of P. oleovorans with DEG, the presence of PEG200 and PEG400 also had an effect on cell growth, PHO yield and cell viability. Furthermore, a hybrid copolymer of PHO-PEG200 was synthesised. The synthesis of these natural-synthetic hybrid copolymers could lead the way for a wide variety of PHA-PEG copolymers with a range of bioactive properties. All thermal properties of PHB were higher than those of PHB-DEG. This may be due to a combination of lower PHB molecular weight and termination of the chains by DEG, i.e. ???DEGylation???. However, PHB-DEG was more elastomeric when compared to PHB, showing properties similar to its copolymer with 20 mol% 3-hydroxyvalerate. Contact angles revealed that the PHB-DEG film was slightly more hydrophilic than PHB. Despite the large difference in their respective proportions, the comparatively small DEG component exerted an influence on chain confirmation, such that solvent casting under humid conditions apparently induced self-assembly and formed a disordered microporous film. DEGylation of PHO also had noticeable effects on the physiochemical properties of the biopolymer. A major decrease in molecular weight, together with the termination of hydrophobic PHO chains with hydrophilic end-groups resulted in changes to its thermal properties when compared to PHO. In comparison to PHO, solvent cast films of PHO-DEG were apparently less flexible, but more hydrophilic.

The Compact Linear Fresnel Reflector is a solar thermal energy system currently at prototype stage in Australia. The system uses parallel rows of mirrors lined up underneath a long, elevated thermal absorber. The mirrors move so as to focus solar radiation onto the absorber; the absorber contains a bank of high-pressure water pipes through which water is pumped and gradually boils. The process of ??direct steam generation?? in very long pipes, up to 300 m in a straight run, has not previously been performed at this scale; other systems use shorter pipe runs, or use other fluids such as non-boiling oil. This thesis addresses a broad range of design issues relating to the CLFR prototype and its components. Beam solar radiation at the prototype site is estimated from available data including satellite-derived and ground-based measurements. Existing correlations for the beam component of global radiation do not apply well to Australian conditions so a new correlation is proposed. Computational fluid dynamics simulations establish radiative heat-loss as the dominant mode for the thermal absorber. Results are gathered for a range of sizes and shapes, and heat-loss correlations are derived for use in subsequent simulation. Two-phase flow in the absorber direct-steam-generation process is examined, and a detailed model including, pipe-friction pressure drops, flow-boiling heat transfer and cavity heat loss is presented, with validation against the experimental results of other workers. A series of ??performance maps?? give the predicted outlet flow regime for varied inlet conditions, allowing selection of desired operating points. A full system model is given that integrates this absorber model with ancillary components including the pump and connecting pipework; the model is used to evaluate pumping requirements and to establish expected operating conditions. The inherent pressure instability arising from the two phase flow is examined and orifice plates are sizes to stabilise this effect. A dynamic model for the absorber pipe flow using fully implicit finite difference techniques and accurate IAPWS-IF97 steam properties gives the predicted behaviour during solar transients at both long and short time-scales.

The use of lean, premixed combustion in gas turbines is now widespread due to their low NOx emissions. Such systems are, however, susceptible to a phenomenon called thermoacoustic instability, which occurs as a result of unstable coupling between the combustion chamber acoustics and the flame. It can lead to large amplitude pressure oscillations within a combustor at frequencies in the hundreds of hertz. These pressure oscillations can result in unacceptably large noise levels, flame blow-out, reduced performance and fatigue failure of the combustor walls. This thesis investigates two problems of particular relevance to thermoacoustic instability. (For complete abstract open document)

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 74-80)

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Tulsa. / Bibliography: leaves 373-384.

Thesis (Ph. D.)--University of Toledo, 2008. / Typescript. "Submitted as partial fulfillment of the requirements for the Doctor of Philosophy in Chemistry." Includes bibliographical references (leaves 168-172).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1930. / Typescript. Title from PDF title page (viewed Nov. 6, 2008). Includes bibliographical references (p. [37]). Online version of the print original.