Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references (leaves 166-173). Also available in an electronic version.

Thesis (Ph. D.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (viewed on September 14, 2006). Thesis advisor: Robert D. Hatcher. Vita. Includes bibliographical references.

No description available.

>Magister Scientiae - MSc / The burial history, thermal maturity and petroleum generation history of the F-O Gas Field, Bredasdorp Basin have been studied using 3D basin and petroleum systems modelling approach. The investigated sedimentary basin for this study evolved around mid-late Jurassic to early Cretaceous times when Southern Africa rifted from South America. The F-O field is located 40 km SE of the F-A platform which supplies gas and condensate to the PetroSA ‘Gas to Liquid’ plant located in Mossel Bay. As data integration is an integral part of the applied modelling concept, 2D seismic profile and well data (i.e. logs and reports from four drilled wells) were integrated into a 3D structural model of the basin. Four source rock intervals (three from the Early Cretaceous stages namely; Hauterivian, Barremian, Aptian and one from the Late Cretaceous Turonian stage) were incorporated into the 3D model for evaluating source rock maturation and petroleum generation potential of the F-O Gas Field. Additionally, measured present-day temperature, vitrinite reflectance, source potential data, basin burial and thermal history and timing of source rock maturation, petroleum generation and expulsion were forwardly simulated using a 3D basin modelling technique. At present-day, Turonian source rock is mainly in early oil (0.55-0.7% VRo) window, while the Aptian and Barremian source rocks are in the main oil (0.7-1.0% VRo) window, and the Hauterivian source rock is mainly in the main oil (0.7-1.0% VRo) to late oil (1.0-1.3% VRo) window. In the entire four source rock intervals the northern domain of the modelled area show low transformation, indicated by low maturity values that are attributable to less overburden thickness. Petroleum generation begins in later part of Early Cretaceous, corresponding to high heat flow and rapid subsidence/ sedimentation rates. The Barremian and Aptian source rocks are the main petroleum generators, and both shows very high expulsion efficiencies. The modelling results however indicate that the younger Aptian source rock could be regarded as the best source rock out of the four modelled source rocks in the F-O field due to its quantity (i.e. highest TOC of 3%), quality (Type II with HI values of 400) and highest remaining potential. At present-day, ~1209 Mtons of hydrocarbons were cumulatively generated and peak generation occurred at ~43 Ma with over 581 Mtons generated. Finally, the results of this study can directly be applied for play to prospect risk analysis of the F-O gas field.

Laboratory and field investigations during the past ten years have demonstrated that certain microorganisms can cause deleterious effects in jet fuel tank systems. These investigations have brought about new concepts concerning the mechanisms of utilization of certain constituents in jet fuel tanks by microorganisms. Since the presence of microorganisms is inevitable in fuel systems, research efforts have been directed towards identification and determination of the types of microorganisms which can utilize jet fuel hydrocarbons, fuel additives, polyurethane foam structural materials, and particular hydrocarbons present in the fuel.

In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3+) or (Y3+) salts in nonaqueous solvents forming amorphous networks with gel properties. The chalcogels obtained after supercritical drying have high BET surface areas. These chalcogels showed higher adsorption capacity of toluene vapor over cyclohexane vapor and high selectivity of CO2 over CH4 or H2. The uptake capacity and selectivity of toluene and CO2 adsorption of Co0.5Sb0.33MoS4 were significantly enhanced by the post-synthetic modifications of various metal species like Ni2+, Li+, and Mg2+.

Releases of nonaqueous phase liquids (NAPLs) to groundwater systems are a serious and widespread problem throughout the United States. Research was conducted to determine if numerical groundwater flow and transport models could evaluate the effectiveness of alternative remedial strategies to reduce dissolved hydrocarbon contamination in aquifers, and therefore serve as tools to aid environmental managers in the remedial decision making process. A fuel distribution terminal in the Eastern United States was selected as the test site. A release of diesel and jet fuels from the terminal loading rack area contaminated the unconfined aquifer beneath the terminal and migrated off-site, impacting commercial and residential areas. In the analyses, groundwater flow and transport models were calibrated to site data. The calibrated models were applied to simulate four remedial options: (1) natural attenuation, (2) groundwater extraction, (3) groundwater flushing, and (4) microbial fences. Results of the predictive simulations indicated that the groundwater flushing remedial option provided the greatest reduction of benzene and TEX mass from the NAPL source as well as the lowest concentrations of benzene and TEX in the aquifer. The calibrated numerical models were able to predict the effectiveness of various remedial options and provide a basis for comparison. The modeling in conjunction with other factors, such as cost, were utilized to facilitate the decision making process. / Master of Science

Although environmental monitoring of polycyclic aromatic hydrocarbons (PAH) is an essential step to prevent human exposure to contaminated sites, it provides little information on the actual human uptake and subsequent risks. To this end, urine analysis of short-term biomarkers such as PAH metabolites fill an important niche. The general approach follows the sequence of urine hydrolysis, sample clean-up and pre-concentration, chromatographic separation and determination. Whereas chromatographic methods are based on well established laboratory techniques, the development of easy-to-use, cost-effective and large sample throughput techniques is becoming increasingly relevant to investigate adverse PAH effects on large human populations. This thesis compares the room-temperature, 77K and 4.2K fluorescence properties of 1-naphthol, 2-naphthol, 1-hydroxypyrene, 2-hydroxyfluorene, 3-hydroxybenzopyrene and 9-hydroxyphenanthrene. These metabolites are used as model biomarkers to investigate the analytical potential of a simple method of analysis based on Solid-Phase Extraction and Room-Temperature Fluorimetry. Metabolites are directly determined in the eluting solvent (methanol) without the need of previous separation via multidimensional formats. Metabolite recoveries varied between 87 ± 1.51% (9-hydroxyphenanthrene) and 99 ± 1.05% (3-hydroxybenzopyrene). For 10mL of urine samples, limits of detection varied between 0.01ng.mL-1 (3-hydroxybenzopyrene) and 0.6ng.mL-1 (2-hydroxynaphthalene). These figures of merit demonstrate the potential of this approach for screening purposes