Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [170]-186).

Thesis (Ph.D.)--Kent State University, 2008. / Title from PDF t.p. (viewed May 28, 2009). Advisor: Mietek Jaroniec. Keywords: mesoporous carbons, inverse replication, hard templating, OMC, CMK-3, CMK-5, mesoporous silicas, OMS, SBA-15, MCM-48, KIT-6, colloids, colloidal crystal, nanomaterials, gas adsorption. Includes bibliographical references (p. 184-194).

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 195-203).

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 147-157).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Philip C. Bennett. Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed July 24, 2007. Includes bibliographical references (p. 154-161).

Convection in magma chambers, driven by compositional density differences, is thought to be a major process in fractionation of liquid from crystals in the differentiation of magmas. Compositional convection has been tested for by undertaking two sets of experiments in silicate melts, and by re-examining the vertically differentiated gabbro-granophyre Glen More ring dyke on the Isle of Mull. Crystal growth quenching experiments have been carried out in a synthetic basalt in which iron is replaced by cobalt. Co-Mg olivine was overgrown on olivine seeds cemented in alumina crucibles and the glasses produced on quenching were analysed by EPMA for compositional variation at and above the overgrowth-glass interface. Boundary layers up to 50?m wide, and depleted in Co and Mg by upto 25 %, have been found at crystal-glass interfaces, and plumes of the same melt have been detected above the apexes of growing olivine crystals. The computed density difference which causes the convection of this boundary layer, melt is in the region of 1 %. This phenomenon, known as compositional convection, has been seen associated with dissolving crystals in silicate melts, and around growing crystals in aqueous salt solutions, but this is the first time it has been reported accompanying crystal growth in silicate melts. Other experiments in which hematite underwent dissolution in a natural basalt melt show that dense, Fe-enriched melt can be lifted above its origin by the buoyant rise of bubbles. In both sets of experiments a zone of buoyant boundary layer melt has been produced by side-wall crystallization of hercynite. This zone of melt has convected up and has ponded beneath the meniscus by a process that can be likened to side-wall crystallization in magma chambers. Petrological, mineralogical, textural, and new geochemical evidence from the re-examination of the Glen More ring dyke strongly suggests that the petrological variation is the result of a magma mixing mechanism. It is proposed that this was produced by the injection of a basic magma which underwent partial consolidation. This was then followed by a second injection of a silicic magma which underwent partial mixing with the dioritic residual magma remaining after crystallization of gabbros from the initial magma.

Vitrification is a well-established waste treatment method that has been used for silicate based wastes to achieve waste volume reduction and improve chemical stability before further use. However, the poor mechanical strength of the vitrified products has led to a low commercial value and thus an unjustifiable use of energy-intensive thermal technology over the cheaper, although environmentally unsatisfactory, land disposal option. To overcome this issue, the emphasis of this work lies in demonstrating the feasibility of fabricating dense glass-ceramics from several types of waste and combination of wastes, which are generally superior to their parent glasses in their mechanical performance, as well as highly porous glassceramics to be used in building industries as an alternative to conventional waste disposal. The first part of the research work demonstrated the ease of production of an array of relatively dense glass-ceramic material from coal ash from thermal power plants using powder sintering technology. These products had robust physical and mechanical properties suitable to compete against commercially available building materials such as granite and marble for the floor and wall covering applications. A fully-dense, fine-grained, high-strength glass-ceramic was also fabricated from Feslag using an economically viable single-stage melt heat-treatment route. The ironslag derived glass-ceramic material had a unique composition, with an associated microstructure containing a high content of titanium-rich compounds, and has the potential for non-critical load-bearing applications. Finally, the thesis provides the results of an experimental study concerning with the production of highly porous glass-ceramic foams from a mixture of coal ash and waste glass with the addition of an inorganic foaming agent. The correlations between physical, thermal, and mechanical properties were carried out based on results from practical experiments, physical model studies and numerical simulations using X-ray microtomography and finite element analysis. It was concluded that, these waste-derived materials have the potential to be used in building applications where there can be a large demand to meet the large volumes of wastes available.

Previous work done at the Brigham Young University by Andelin^1, Roberts^2, and Olsen^3, has established the mechanism by which xanthate collectors are adsorbed on molybdenite ores to produce the hydrophobic surfaces necessary for flotation. This thesis is an attempt to better understand the mechanism by which the silicate minerals, which are found in conjunction with the ores, become hydrophyllic and as a result are not floated when in contact with air bubbles. It has been previously established that silicate minerals do adsorb cations on their surfaces^4. The present study has been undertaken to more fully understand the mechanism by which the cations are adsorbed, since the adsorbed cations are at least partially responsible for the hydrophyllic nature of the aluminum silicates. The present study shall be limited to the clays illite, beidellite, bentonite, and kaolinite, which are a group of the aluminum silicate minerals.

No description available.