Recently, there has been increased effort in researching methods for producing hollow nanostructures because of their potential impact in the fields of catalysis, separation processes, drug delivery, and energy storage and conversion devices. The purpose of this thesis is to describe a method for forming hollow inorganic-organic hybrid nanoboxes and nanoframes. This approach relies upon ionic liquid (1-butyl-3-methyl-imidazolium chloride) mediated auto-templating assembly of CaCO3 and chitosan to form nanoframes (two open faces) and nanoboxes (one open face). The average dimension of the nanostructures formed was 339 ± 95 x 299 ± 89 nm. Detailed structure of nanoboxes and nanoframes were obtained by 3-D electron tomography and X-ray diffraction. Chemical bonding was determined by FTIR, and the ratio of organics to inorganics in the nanostructures was determined by thermal gravimetric analysis. The chitosan to CaCO3 weigh ratio, mixing strength, temperature, and dialysis time were varied to further elucidate the method of formation. It was found that increasing the mixing power caused the equilibrium nanostructure dimension to decrease. On the other hand, varying the experimental temperature in the range of 80 to 160˚C did not affect the nanostructure dimension. The dialysis study showed that during dialysis the nanostructure core was increasingly removed. Nanoframes were observed after 72 hours of dialysis. With further dialysis, there was continued erosion of nanoframes. Results indicate that the concentration gradient and the solubility difference between the mixture components were responsible for this transformation.

The Winland R35 method [Log R35 = 0.732 + 0.588 (Log Kair) 0.864 (Log O)] is based on the relationship between porosity, permeability, and pore throat radius at the point of 35% mercury saturation in capillary pressure measurements and is generally reliable in rocks with only intergranular porosity (such as sandstone) where pore and pore throat geometry are related closely to rock texture. Carbonate pores are not always so; consequently, the Winland method is not as reliable for assessing reservoir quality in carbonate reservoirs. To evaluate alternatives to the conventional Winland technique, based on rock facies characteristics, samples from the Jurassic Smackover Formation in Alabama and the Permian Clearfork Formation in Texas were tested for reservoir quality with use of the Winland R35 and Pittman methods to determine if either method is more reliable in carbonate reservoir studies. Pittman's modification of the Winland method was found to be more accurate graphically. A third method for evaluating reservoir rock character is provided by Lucia. This method is based on geological rather than petrophysical characteristics, and it revealed that pore throat sizes at 35% mercury saturation may include a variety of depositional and diagenetic rock fabrics. The Winland and Pittman petrophysical evaluation techniques, as well as the Lucia geological evaluation technique - when based on depositional facies alone - do not provide reliable measures of reservoir quality. An alternative method based on genetic pore type presented by Ahr in 2005 was tested for comparison. Using a porosity-permeability plot based on the pore type, the relationship between porosity, permeability, and pore type was found to be strong and reproducible. When the ratio of permeability to porosity was used in combination with Ahr genetic pore types, the results indicate that barriers, baffles, and flow units can be reliably defined. This study demonstrates that the use of pore types in conjunction with capillary pressure measurements is a more reliable method for evaluating carbonate reservoirs than any alternative method that is based on depositional facies or rock fabrics alone.

Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Bibliography: leaves 155-160.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 99-101). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1931. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed December 14, 2009) Includes bibliographical references (p. 75).

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The Lower Parmeener Supergroup consists of 500 to 900 metres of marine and terrigenous sedimentary rocks, deposited in the high-latitude Tasmania Basin during the late Carboniferous to middle Permian, at the end of the late Paleozoic ice age. Two bioclastic carbonate units, the Darlington and Berriedale limestones, are of particular interest due to their formation in this polar, cold-water environment. Both limestones contain ice-rafted debris scattered throughout, signifying numerous icebergs, and are under- and over-lain by glendonitic siltstone indicating near-freezing seawater. Despite the unusual environment, seawater in the Permian Tasmania Basin was, with the exception of an anomalously high 13C value, isotopically and chemically similar to modern seawater. These limestones consist of a high-abundance, low-diversity heterozoan assemblage, dominated by large, robust brachiopods, bryozoans, and Eurydesma bivalves. Sponge spicules and crinoids are locally important constituents. The carbonates are interpreted to have been deposited in mid-shelf environments during sea-level highstands, where the faunal communities were beyond the depths of grounding icebergs, and sufficiently outboard from terrigenous sediment influx and brackish water. Growth and preservation of biogenic carbonates were promoted by up-welling of nutrient-rich water, which sustained high levels of primary productivity in the water column and phosphate concentrations in the sediment. Lower Parmeener Supergroup carbonates were exposed to a complex series of diagenetic processes, commencing on the seafloor and continuing during rapid burial. Limestone composition was further modified by diagenetic fluids associated with the intrusion of Mesozoic igneous rocks. Alteration in the marine paleoenvironment was both destructive and constructive; although dissolution took place there was also coeval precipitation of fibrous calcite cement, phosphate, and glauconite. These processes are interpreted to have been promoted by mixing of marine waters and enabled by microbial degradation of organic matter. In contrast, meteoric diagenesis was insignificant, being confined to minor dissolution and localized cementation, although mechanical compaction was ubiquitous. Chemical compaction was instigated at burial to depths of approximately 150 m, and promoted extensive precipitation of ferroan calcite. Diagenesis may well have ended here, except for the subsequent intrusion of massive Mesozoic diabases and associated injection of silicifying fluids into the limestones. Finally, fractures associated with Cretaceous uplift were filled with late-stage non-ferroan calcite cement. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2008-04-23 11:12:58.461 / NSERC

Records of stable oxygen isotope variations from a variety of proxies have been used in palaeoclimatic research since the 1950’s. Several studies have applied stable isotope analysis of lake sediments to reconstruct past climate changes in central and northern Sweden, including a study of Lake Blektjärnen in Jämtland, central Sweden, by Andersson (2010). In this study, sediments from that same lake were sampled for stable isotope analysis of bulk carbonates with the aim to improve the resolution of the isotopic record for the last two millennia. The results indicate a shift from relatively drier to wetter conditions between ~2,300–1,300 cal. years BP, generally wet conditions close to the Medieval Warm Period (~1,000–750 cal. years BP) and generally dry conditions during the Little Ice Age (~550–150 cal. years BP). These results are in agreement with previous palaeoclimatic reconstructions in the region. The isotopic record of Lake Blektjärnen was completed for the last ~2,350 years at a resolution of ~15 years per sample, three times higher than that of the previous study, displaying the advantages of bulk carbonate sampling for stable isotope analysis and providing a high-resolution dataset on humidity changes in central Sweden during the late Holocene.