Photonic crystal is the periodic structure with different refractive index media. Its photonic-bandgap characteristics could be used to make the photonic crystal lasers. Because of the difficulty of fabrication, the development of three-dimensional photonic crystal is far behind the two-dimensional and one-dimensional photonic crystals. Blue phase liquid crystals are formed by periodic lattice structure with double-twisted cylinder, therefore it is a three-dimensional self-assembled photonic crystal. The objective in this study is to fabricate the three-dimensional photonic crystal blue phase liquid crystal laser by investigating the materials and the fabricating conditions. In this thesis, we doped the laser dye in the blue phase liquid crystal to make the laser device. Firstly, we studied blue phase temperature range and Bragg reflection wavelength under different material ratio. The blue phase lattice structures under different cool rate and surface treatment could be investigated by observing Kossel diagram . According to the experiment results, three-dimensional blue phase photonic crystal laser under room temperature could be achieved through appropriate material ratio, and its Bragg reflection wavelength is corresponds to the emission spectrum of the doped laser dye. By decreasing the cooling rate and the adapting homogeneous alignment of the substrates, the laser output will become more stable. As the result, we successfully fabricated the three-dimensional liquid crystal blue phase laser device at room temperature, and measured three-dimensional laser output. In addition, We study the relations between the laser emission direction and the alignment direction, and the temperature tuning characteristics of the laser wavelength. These results are very useful for the development of the three dimension tunable laser.

Thesis (M.S.)--Oregon State University, 2002. / Typescript (photocopy). Includes bibliographical references (leaves 70-74). Also available online.

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Thesis (M. Appl. Sc.)--University of Canberra, 1991. / Includes bibliographical references (p. 184-209).

Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Plant Biology." Includes bibliographical references (p. 28-31).

Thesis (Ph. D.)--University of Chicago, Department of Chemistry, June 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (M.Sc.)--York University, 2004. Graduate Programme in Biology. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ99289

The Bahamas are thousands of islands stretching along the coast of Florida and south to the tropic of cancer. An aerialv iew, spectaculaar s it is, shows only a small part of the islands, a larger part is submerged and discernible only by the abundance of blue dots onshorea nd in the shallow water around the islands. The blue holes are entrancesto an underwater world wherein biology seems to have slowed down to offer a fascinating view of species rarely seen elsewhere, and of rock formations that tell a story of the subterranianw orld below the islands. My studies were inspired by curiosity and the desire to make a contribution to the preservationo f this unique and irreplaceablew indow into the pastf or geologistsa nd biologists alike. Important questions as to how the caves formed and when and what the role of cavel ife might havep layed in the excavationp rocessesa re addressedin this thesis. As a result of these studies bacteria must be considered as possibly active participantsi n the formation processesa fter the time when the rising watertablef looded all the Bahamian caves. The layering, often in hypersharp zones of biological material, matches or is perhaps caused by, equally dramatic changes in hydrogen ions and acetate and sulphate concentrations. In both caves, pH profiles were observed that varied sharply over very short distances. In all three study sites it could be shown that, vertically and horizontally, the geochemical perimeters varied dramatically. Organically mediated processes are a dominant control on dissolution within the fresh, mixing, and saline zone. The combined generationof C02 results, known from earlier studies, and 112S and other bacterially measured activity, supports this finding. Retention of suspended organic matter was directly proportional to the salinity gradient. Elevated levels of DOC, POM, and acetate at the two major density interfaces confirm this finding. In the results, generated from CHN&S methods, wall rock material was found to contain residual carbon for potential microbial use, and large bacterial populations were identified through the SEM method in excess of what was measured within the water column. Significant lepidocrocite deposits (dimorphose iron oxihydroxide) were identified as a fraction of the cave sediment, and material known as "mung7, based on amino-acid analysis, was shown to be proteinaceous. This mung appears to be unique to caves in the Bahamas. In a sense the cave system is an underground geo-biosphere wherein the peculiar water flow patterns foster a specific, sometimes rich and unusual, fauna and flora that is a treasure for science and a sight for humans to enjoy.

The present study was conducted on Ezemvelo Nature Reserve in the highveld grasslands of South Africa. The evidence for ecological separation between the black and blue wildebeest was investigated in an area with suboptimal habitat for both types of wildebeest. Habitat selection and separation of the black and blue wildebeest population were investigated at three main scales. A combination of logistic regression analysis, discriminant analysis and hypothesis testing techniques were used to determine whether habitat separation occurred between the black and blue wildebeest at the various scales. Seasonal, social group and weather influences on the habitat selection of both types of wildebeest were also investigated. Black and blue wildebeest showed resource partitioning in terms of habitat at the macro and mesoscales but not at the microscale. The preference for open areas by the black wildebeest and its more specialised territoriality were found to be the main driving factors contributing to the habitat separation of the two types of wildebeest. The population of black wildebeest was found to be decreasing while the blue wildebeest population was found to be increasing in the study area during the study period. Spatial overlap between the black and blue wildebeest was found to be low. Little evidence of interference interspecific competition between the black and blue wildebeest was found. It was, however, concluded that exploitative competition between the two types of wildebeest would be found in areas with low habitat heterogeneity. Ecological separation between the black and blue wildebeest was found to be incomplete. However, the coexistence of the black and blue wildebeest was deemed possible provided habitat heterogeneity in terms of the factors found to be important for habitat separation was high and population sizes were strictly monitored and actively controlled. Finally, a number of additional management recommendations for the black and blue wildebeest at Ezemvelo Nature Reserve and for other reserves confining both types of wildebeest together based on the results of this study were made. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / MSc / unrestricted