Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 342-353).

Thesis (Ph. D.)--University of Chicago, Dept. of the Geophysical Sciences, June 2000. / Includes bibliographical references. Also available on the Internet.

Thesis--Columbia University. / "A critical review on water vapor pressure and solubility of major atmospheric gases in NaCl solution and sea salt solution in comparison with that in pure water": leaves 146-176. Includes bibliographies.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisors: Steven L. Bryant and James W. Jennings Jr. Vita. Includes bibliographical references.

Thesis (M.S.)--Baylor University, 2006. / Includes bibliographical references (p. 185-188).

No description available.

Th. doct.-ing.--Lille 1, 1979. N°: 235. / Rés.

The Lower Carboniferous ('mid'-Courceyan to early Chadian) Black Rock Limestone ramp succession of SW Britain, accumulated along the southern margin of the Welsh-Brabant Massif during the early stage of development of the SW European foreland basin. Two depositional cycles are recognized which culminate in the subaerial exposure of those sequences in a more landward setting. The lower depositional cycle includes the Barry Harbour Limestone Formation, which contains a variety of storm-related sedimentary structures including hummocky cross-stratification. This is conformably overlain by the tidally influenced, cross-stratified Brofiscin Oolite Formation which locally displays evidence of subaerial exposure. Seven sedimentary lithofacies are identified in these two formations, which record a distal to proximal, shallowing-upward trend that passes from beneath mean wave-base to above fairweather wave-base. The upper depositional cycle of the Friars Point Limestone Formation includes the volcanics at Middle Hope, the Waulsortian facies at Castlemartin and Cannington Park, and is capped by the (herein named) Portishead Paleosol Beds (near Bristol). Above the basal transgressive sequence, the Friars Point Limestone consists of two distinct offshore ramp facies belts. The more proximal inner ramp facies belt was more strongly influenced by storm-related currents and exhibits tubular tempestites (storm sediment-filled burrows). The finer-grained, outer ramp facies belt is extensively bioturbated and preserves few features indicative of deposition from storm-related currents. The effects and relative timing of differential subsidence was elucidated by using the well documented biostratigraphy to separate the succession into isochronous units. The onset of pronounced differential subsidence was signified by volcanic activity at Middle Hope (Weston-super-Mare). The volcanic tuffs form a coarsening- and shallowing-upward sequence which records the development of a localised, probably non-emergent, offshore-volcanic high. Recognition of a major eustatic sea level fall at the end of the Courceyan and during the early part of the Chadian, is revealed by studying the decline of the Waulsortian reefs in an offshore ramp setting and evaluating the regional significance of the Portishead Paleosol Beds. Overall, the development of the Black Rock Limestone ramp was the result of the interplay between eustacy and tectonism. A full petrographic and geochemical analysis of the Waulsortian dolomites at Castlemartin, including the use of stable isotopes revealed that dolomitization occurred during burial, most probably as a result of basin dewatering.

D.Phil. (Chemistry) / The formation ofcalcium carbonate scale is a major problem in industry as well as in households. The scale that forms acts as an insulator, decreasing the effectiveness ofheat exchangers, be it a water cooling systems or a water heating system This raises the energy costs ofthat company and the costs of cleaning are expensive. Physical water treatment has been used for at least 50 years in the treatment ofwater with scale forming potential to reduce the formation ofthis scale. In thisthesis, tests were made on a magnetic and constantelectric field antiscaling device on the effect they have, ifany, on CaC03 scale formation. An attempt will be made to give a mechanism for any effect found. It is hoped that a contribution is made by this research in clearing up the misconceptions that abound in this controversial field ofphysical water treatment. Water with a high calcium bicarbonate content was exposed to the antiscaling devices and then calcium carbonate was forced to precipitate out ofsolution. This precipitation was followed by meauring the pH and the crystal structure ofthe precipitated calcium carbonate was studied. The most important results were that by exposing the calcium bicarbonate solution to an antiscalingdevice, the start ofprecipitation ofthe calcium carbonate was significantly delayed and the crystal structure of the calcium carbonate that formed was predominantly aragonite as opposed to calcite that usually formed.

White lime is used in many industries in South Africa but is not produced locally and must be imported. Many technologies have been suggested for the large-scale manufacture of calcium carbonate but these are not necessarily suitable for application in South Africa. This study investigated a chemical preparation of calcium carbonate combined with biological purification Calcium containing materials from the Pretoria Portland Cement, Lime Division factory at Lime Acres in the Northern Cape were studied as the starting materials for the manufacture. Investigation showed that they contained various impurities, including iron and manganese compounds which were largely responsible for the brown-grey colour of the lime products. Complete dissolution of calcium hydroxide, the purest of the potential starting materials, and subsequent hydroxide precipitation was not successful in removing all iron and manganese. Precipitation with sulfide ions was successfill, decreasing levels of metals to below the detection limit of atomic absorption spectrophotometry. Studies of all potential starting materials revealed that the levels of impurities in the starting material did not have a large effect on levels of impurities in the calcium carbonate produced. It was therefore possible to convert the residual calcium oxide or hydroxide in waste lime dusts to white calcium carbonate, a marketable prciduct Recycling of the water and starting material used in the process served to increase, rather than decrease, the purity of the calcium carbonate product. This allows for water conservation as water is not consumed in the process but merely utilised. When waste lime dust was used as the starting material, sulfate was found in the product. While still a white lime, the calcium carbonate was not chemically pure. Sulfate removal was therefore investigated and the use of sulfate-reducing bacteria was studied as a novel application. A mixed sulfate-reducing bacterial population was isolated and found to be hIghly active at sulfate concentrations between 0.2 and 2 ~~~. They were capable of autotrophic growth and could reduce sulfate in solutions with elevated pH and in calcium carbonate suspensions, although they did not grow readily in these media. A process was designed for the production of bulk quantities of calcium carbonate making use of the facilities and materials available at Lime Acres. This was tested using a small scale bench-top reactor series, with favourable results. The process would allow automatic, continuous production of large quantities of white lime using waste lime dust. Provision was also made for manufacture of smaller quantities of pure calcium carbonate using sulfate-reducing bacteria to remove the sulfate impurity.