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This thesis is concerned with the synthesis and reactions of functionalised 3- liydroxypyridines, in particular 2-aryl- and 2-heteroary 1-3-liydroxypyridines by non- coupling methodology, from furan precursors. Chapter 1 reviews the synthesis and reactions of 3-hydroxypyridines. Chapter 2 describes the synthesis of 2-acylfurans via differing methods, which include acylation of the furan nucleus, Grignard reactions of furaldehydes and, most notably, reaction of lithiofurans with reagents containing a nitrile component. Chapter 3 concerns reaction of acylfurans with ammonia at high pressure and temperature to produce 3-hydroxypyridines. We have found that this ring expansion is able to withstand many differing substituents including bromine. Further development of the pyridine ring system involves reaction of the ring atoms or substituents, including protection of the hydroxy group. This ring expansion was used in the development of a novel azabenzotriazole starting from a simple furan compound, and this is reported in Chapter 4.The methodology described in this thesis is versatile and has allowed access to a range of novel pyridine derivatives in synthetically useful quantities which should be of interest in many areas of organic chemistry.

Integrated ring resonators have attracted a considerable interest in optical communications because of their small size and wide range of applicability. Here we consider several aspects of these devices, beginning with a tunable hybrid ring resonators consisting of a silicon over insulator (SOI) ring covered with a polymer layer in a variable electric field. Varying the field changes the polymer refractive index and consequently the resonance condition of the cavity. This device offers a large degree of optical confinement together with a high modulation speed. Subsequently, we design and present fabrication results for a Wavelength Division Multiplexing (WDM) multiplexer/demultiplexer formed from a series of ring resonators with two channels separated by 50 GHz each that is predicted to exhibit a free spectral range (FSR) of 100 GHz , signal dispersion less than 30 ps/nm and a signal cross-talk less than -23 dB. Finally, we analyze the application of the coupled ring waveguide circuit to rotation sensors based on the Sagnac phase shift. Here, however our analysis indicates that a single ring, of the same area exhibits a higher degree of sensitivity to rotational motion than a multiple ring circuit.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1976. / Bibliography: leaves 203-208. / Microfiche. / xv, 208 leaves ill

Patterns in the floristic composition, stand structure, species richness and environmental characteristics of plant communities at a number of spatial scales were examined in Ku-ring-gai Chase National Park, New South Wales. Vegetation patterns in eastern Australia have often been related primarily to a single environmental variable, soil phosphorus concentration. This study examines the 'single nutrient' hypothesis regarding the distribution of plant species. If soil phosphorus concentration is the majot factor affecting the distribution of plant species, then this should be highly correlated with spatial patterns in the floristic composition of plant communities within the study area. Floristic composition was determined as the frequencies of all vascular species occuring within duplicate 500 m2 quadrants from fifty sites within the Park. Environmental data consisted of 21 variables, including soil physical and chemical characteristics, from each quadrant. The patterns in floristic composition and environmental factors are described and the relationships between composition and environment were examined. through indirect and direct gradient analyses. The measured environmental factors showed strong correlations with floristic patterns; however, two scales of species distributions were apparent: between and within soil type. Direct gradient analyses of composition and environmental data showed soil phosphorus concentration was inadequate in explaining the observed patterns in floristic composition of plant communities are a response to complex multivariable environmental gradients. The structural characteristics of vegetation stands were examined through the development of a multivariate approach to the classification of stand structure. This multivariate approach is essentially a modification of an existing scheme utilising foliage projective cover of various recognisable strata within the strands. Multivariate classification and ordinations of plant communities based on structural characteristics showed strong correspondence to that obtained by compositional analyses. The complex multivariable gradient hypothesis is supported from results examining stand structure-environment relationships. The relationship between species richness and richness of three growth-form types (tree, shrubs, and herbs) and environmental variables were examined through generalised linear models. The measured environmental variables showed strong relationships with species richness, consistent with the results found multivariately with floristic composition and stand structure. No single measured environmental variable adequately predicted the observed patterns in species richness, rather species richness showed strong relationships with complex multivariable environmental gradients. This study clearly demonstrates the the 'single-nutrient' or 'phosphorus' hypothesis is inadequate in explaining all the patterns in the various components of vegetation within Ku-ring-gai Chase National Park. The complex multivariable environmental gradient hypothesis suggested by the relationships between floristic composition and environmental variables is supported by the relationships exhibited by two other attributes of vegetation communities: stand structure and species richness. Further studies testing the significance of the complex multivariable environmental gradient hypothesis are required.

Typescript (photocopy) / xii, 182 leaves, [60] leaves of plates : ill. ; 30 cm / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Plant Pathology, University of Adelaide, 1981

x, 99 leaves : ill. ; 25 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1974) from the Dept. of Plant Pathology, University of Adelaide

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Mar. 4, 2008). Vita. Includes bibliographical references.

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

Thesis (Ph. D.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references. Online version available on the World Wide Web.