No description available.

Thesis (Ph. D.)--University of Sydney, 2002. / Title from title screen (viewed Apr. 24, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Physics, Faculty of Science. Degree awarded 2002; thesis submitted 2001. Includes bibliographical references. Also available in print.

The question of how and when life originated on t his planet has always been an intriguing one, exceeded perhaps in fascination only by that area of speculation which concerns itself with death and the afterlife . The latter problem has generally been approached along theological lines; the former problem , that of the origin of life, has been widely investigated along scientific lines as well . Indeed, the origin of life has always been one of the fundamental problems of science, and the increasingly sophisticated answers to the problem reflect the increasing potence and applicability of the methods of science.

No description available.

The stationary phase on chemically modified supports for liquid chromatography is described as a mixture of the surface-bonded species, the active unmodified surface, and associated mobile phase components. Each of these three factors in stationary phase formation is examined and improved qualitative and quantitative descriptions of the stationary phase are provided. The role of the active unmodified surface was examined by synthesizing a carbon support and chemically modifying it with octyl groups. The modified carbon had a greater affinity for lipophilic probes than an octyl silica. The lipophilicity of the octyl carbon was attenuated relative to the unmodified carbon. The physical state of the bonded species in C(,18) and C(,8) packings was studied using carbon-13 NMR. Peak widths of 2-7 ppm indicated a liquid-like nature but with restricted movement. Only the 7 to 10 carbons in a C(,18) chain farthest from the surface were sufficiently motile to produce a signal. The C(,8) packing showed more rigid chains with only the top 3 or 4 carbons responding. The liquid-like nature of a C(,18) chain increased with the lipophilic character of the solvent, indicating that solvation of the bonded species was directly related to the mobile phase composition. Changes in temperature had little effect on the physical state of the bonded species, but chromatographic enthalpy measurements showed that changes in stationary phase composition could be induced by warming the column and held by subsequent cooling. Quantitative measurements of stationary phase compositions revealed linear distribution isotherms for the organic modifiers methanol, acetonitrile, and tetrahydrofuran. Chromatographic selectivities for homologous n-alkanols correlated linearly with organic modifier concentrations in the stationary phases. The stationary phase volumes, which increased with increasing modifier concentrations, are interpreted as constituting filling of the pores in the support with a gradient of modifier enrichment toward the surface.

Thesis (Ph. D.)--University of California, San Diego, 1983. / Vita. Includes bibliographical references (leaves 133-138).

Graduation date: 1963

Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Environmental Sciences." Includes bibliographical references (p. 143-149).

Thesis (Ph. D.)--University of Florida, 2005. / Title from title page of source document. Document formatted into pages; contains 189 pages. Includes vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Douglass F. Taber, Dept. of Chemistry & Biochemistry. Includes bibliographical references.