In this research it was shown that the electroless plated palladium deposited as large number of randomly oriented grains, which were separated by grain boundaries (GB). The nano-scale dimensions of these grain boundaries allowed the diffusion of helium through the palladium membrane. This implied that in a dense palladium membrane, the grain boundary network was so convoluted that helium flux could be neglected. The transmission electron microscope (TEM) images of the palladium at room temperature showed grains of about 50 nm in size and nuclei of about 5 nm in size. The TEM images of a pre-annealed Pd sample at 500ºC in hydrogen atmosphere for 48 hours, showed big grains of 100 to 200 nm in size and most of the grain boundary intersections had dihedral angles very close to 120°. However, the pre-annealed Pd sample at 500ºC in helium atmosphere for 48 hours, showed grains of the size of 70 to 100 nm and many of the grain boundary intersections did not show dihedral angles of 120°. This proved that high temperature annealing not only caused significant grain growth and grain boundary (straightening) migration, but also the grain boundary migration was faster in hydrogen than in helium atmosphere. Also, the hydrogen and helium characterization of the palladium membranes showed that the leak formed faster in hydrogen than in helium. Thus, combining the TEM observations with the membrane characterization results, it is possible to conclude that grain boundary migration is one of the most probable reasons for leak formation in palladium composite membranes. The TEM images of the pre-annealed Pd sample also showed that the grain boundaries can achieve an equilibrium configuration within 48 hours of annealing at 500°C in hydrogen. This research helped in better understanding of the role of grain boundary migration on the leak formation in the composite palladium membranes and this information can be useful for the production of leak resistant stable membranes in the future.

Mainline Protestant churches are in crisis. In the Episcopal Church, Sunday attendance has declined nearly 25% in the last decade. Clergy with limited leadership skills are unable to help reverse this trend. But the leadership skills clergy need can be taught. After reviewing literature from studies of church growth and the field of leadership studies, I created a list of vital leadership skills and used it as the basis for a questionnaire sent to the ten Episcopal seminaries. After reviewing these quantitative results and qualitative interviews, I identified organizational management and evangelism as relative weaknesses in Episcopal clergy formation. Interviews showed a variety of curricular and extracurricular strategies to form clergy leaders. Drawing on this research and on studies of professional education and leadership pedagogy, I outline a three-year leadership formation curriculum, which will serve as a model for leadership formation at Berkeley Divinity School.

by Jian-hui Liu. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 112-118). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Opinion dynamics in a society of interacting agents may lead to consensus or to the coexistence of different opinions. The interplay between social network change and opinion formation is complex, because the agents, their social interactions and the changing social structure over time, are themselves complex. DeGroot proposed a prescriptive model for achieving consensus, where agents revise their opinions at each time step by taking a weighted average of the opinions of neighbours. This thesis contains three main contributions. First, we introduce a generalisation of the DeGroot model and examine the long-time behaviour of the model, with and without insistent agents. Second, we consider opinion formation on networks which are themselves dynamic, where the dynamics may be completely random or based on homophily and triadic closure. The weights that agents place on the opinions of neighbours are also dynamic, based on a rule where weights decrease with increased difference in opinions. Third, we examine the effect of a sudden, temporary or permanent shift in the opinions of some agents. Two dynamics are considered for the network change over time; random switching (RS) network dynamics, and homophily and triadic closure (HT) network dynamics. We prove that the RS network dynamics enhances consensus formation and network connectivity, compared to the HT network dynamics where we show by simulation that different opinions can persist. We investigate the in uence of the presence of a minority of insistent agents and prove that for a connected static network, insistent agents with the same opinion in uence the final opinions to converge to their own opinion, thus leading to consensus. In contrast, lack of consensus persists when insistent agents have different opinions. This conclusion also holds for the RS network dynamics model. However, for the HT network dynamics model, coexistence of different opinions can persist even when insistent agents have the same opinion. This finding regarding the HT dynamics is of particular interest as it relates to observations in the real-world. We also investigate the in uence of a sudden shift in the opinions of some agents on the outcome of final opinions. The case of either a temporary shift in opinions or a permanent shift in opinions is examined. Additionally, the in uence of the time of the introduction of a shift, the number and the network positions of initial recipients of the shift in opinions is investigated. The overall effect of an opinion shift is measured by its in uence on the stabilisation time of the final opinions.

No description available.

Feedback -- from stars and supermassive black holes -- is the bottleneck of our understanding on galaxy formation: it is likely to be critical, but neither the working mechanism nor the impact is clear. Supernovae (SNe), the dominant feedback force associated with stars, is the subject of this thesis. We use high-resolution, 3D hydrodynamic simulations to study: (i) how a SN blast wave imparts energy to a multiphase ISM; (ii) how multiple SNe regulate a multiphase ISM; (iii) how SNe drive galactic outflows. We focus on better understanding the physics, quantifying the impacts, and testing the simulations against observations.

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.

The general biosynthetic pathway for tryptophan is known. However, little information has been gathered on how substrates and enzymes interact when phosphoribosylanthranilate isomerase (PRAI) and indole-3-glycerolphosphate synthase (IPGS) convert a substituted phenyl ring, PRA, into an indole moiety, IGP, via 1-(O-carboxyphenylamino)-1-deoxyribulose-5-phosphate (CdRP). There has been no serious synthetic approach to develop methodology to produce a plethora of substrate and product analogues of CdRP. The studies described in this thesis cover methodology focusing on secondary aryl amine formation, using reductive amination, nucleophilic substitution and epoxide ring opening, leading to CdRP analogues. Reductive aminations with D-ribose failed to produce any aryl glycosylamine precursor, possibly due to the low nucleophilicity of aryl amines such as aniline. Removing the aromaticity and using cyclohexylamine produced secondary amines in moderate yield in the presence of benzylpentanal, and NaBH3CN, at a pH of 5.5. This led to a successful reductive amination using anthranilate methyl ester. Secondary aryl amine synthesis via epoxide ring opening proved consistently reproducible. Using LiNTf2 and high equivalents of cyclohexylamine or aniline in neat conditions opened protected epoxides. This has led to the formation of advanced secondary aryl amine synthons and the development of methodology leading to target compounds with functionality at the 1,2 and 5 positions. Nucleophilic substitution using caesium base, high equivalents aniline at room temperature, gave a moderate yield of secondary aryl amines from sulfonyl and bromide good leaving groups. Raising the reaction temperature improved yields using low equivalents of aniline, with the optimal temperature being 50 °C. Ultimately using both the high equivalents of aniline or anthranilate methyl ester and warming the reaction in DMF gave the highest yields of secondary aryl amines. No overalkylated tertiary amine was isolated when a caesium base was used. Boc N-protection of 1-phenylamino-4-pentene and asymmetric dihydroxylation gave the corresponding diol, which was phosphorylated giving the protected target 1,4,5 compound. The methodology leading to the protected target 1,4,5 compound synthesis provides a means to the synthesis additional of CdRP analogues.

Includes bibliographical references. / 12pts in 1. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D.Sc.)--University of Adelaide, (Dept. of Soils, 1949)