Thesis (M.S.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: John Antle. Includes bibliographical references (leaves 115-124).

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 73-74). Also available on the World Wide Web.

Thesis (M.S.) in Ecology and Environmental Science--University of Maine, 2006. / Includes vita. Includes bibliographical references (leaves 73-94).

No description available.

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Robin Gerlach. Includes bibliographical references (leaves 220-225).

A hallmark trait of P. falciparum malaria is sequestration, in which parasite infected erythrocytes (IEs) adhere to the vasculature, causing organ failure and death. Current antimalarials only kill the parasites, necessitating development of anti-adhesion drugs. Using our two-step approach, we can efficiently screen for anti-adhesion small molecules. Screenings of 75libraries using Bio-Plex 200 identified the most active TPI libraries, which were deconvoluted to single compounds. Screenings library TPI 1319 yielded 3 inhibiting non-optimized compounds, each of which inhibits binding between two receptors, CSA and ICAM1, and their binding PfEMP1 domains. Two compounds deconvoluted from TPI 2103 prevent binding between PfEMP1 and ICAM1. Cytoadhesion assays with live IEs support the results seen with Bio-Plex, with best hits showing inhibition below 200 nM. Cytotoxicity testing of active compounds showed minimaltoxicity. Identified hits appear to be amenable to Structure Activity Relationship studies to develop powerful anti-adhesion drugs to treat severe malaria. / Includes bibliography. / Thesis (MS)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

A Thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy in the School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, 2019 / Due to the energy- and carbon-intensive economic structure of South Africa (SA), the country has become one of the biggest contributors to greenhouse gas emissions, emitting more CO2 than any other African country. The ratio of greenhouse gas emissions compared to per capita economic benefit, the so called carbon intensity of the economy, is amongst the highest in the world. Carbon capture and storage (CCS) seems to be the most immediate form of action that can be implemented with the possibility of instantaneous reduction of CO2. The injection of CO2 into deep-unmineable coal seams, although not commercially viable for coal production, is a possible mitigation option under CCS for permanent underground storage of CO2. As a spin-off, useful coal-bed CH4, referred to as enhanced coal bed CH4 (ECBM), could be extracted from the coal seam following CO2 injection. In SA it has been estimated that approximately 1.2 Gt of CO2 could be stored in the coalfields. Although not currently the preferred option for geological storage, coalfields provide the largest onshore CO2 storage possibility. The current research project aimed to study the fundamental differences in CO2 adsorption in a variety of SA coal samples in order to access the CO2 sorption capacities and secondly to evaluate the potential CH4 characteristics of SA coals. The investigation aimed to identify the fundamental differences around the effects of increased pressure under simulated in-seam conditions including super-critical pressures up to ~90 bar for gaseous and supercritical CO2 injection. The effects on CO2 adsorption with regard to the difference in coal moisture contents, simulated in the range from ~0.5 – 4.4% and the influence of increased temperatures in the range of 35 to 55 ˚C were carried out on ten (10) SA coals taking into consideration differences in coal properties, samples with varying rank, ash and maceral compositions were sourced for this research. Then secondly, to evaluate the desorption potential of CH4 for seven (7) selected SA coals. A High Pressure Volumetric adsorption system (HPVAS) was successfully designed and constructed in order to conduct experimental tests to generate the adsorption isotherms for the various parameters tested. Results presented show comparable results with published literature in terms of the degree of variance in coal properties (with respect to rank, maceral and mineral content, ash contents and the effects of moisture, and temperature variance) and the uptake of CO2. Higher rank coals have a greater CO2 absorption propensity, whereas lower rank bituminous coals tend to exhibit lesser CO2 uptake, however, this is dependent on the coals’ petrographic composition. It was clear that samples in the range greater than a vitrinite reflectance of 0.7% (RoVmr) exhibited increased CO2 uptake due to larger macro, increasing meso porosity and micro-pore volumes. Findings related to coal properties; revealed that coals with a higher ash content exhibited a negating effect with regard to enhanced CO2 adsorption. On average, for a 1% increase in ash content in HRC and MRC coals, a decrease of CO2 adsorption capacity of 1.1 mmol/g and 0.018 mmol/g is observed respectively. While for maceral composition these findings suggest that a specific or ideal ratio between only the maceral components, in similar rank coals, is the controlling factor for best CO2 adsorption required. In terms of addressing the adsorption parameters, such as super-critical pressure, temperature and moisture variations inherent in natural coal seams, etc., it was determined that with increased pressure, more adsorption takes place for most coal types. A very positive correlation was found to exist between adsorption of CO2 and desorption of CH4, with increased pressure injections, ranging from sub-critical to super critical pressures, exhibiting increased sorption results, irrespective of coal moisture or temperature effects. From these findings for simulated conditions regarding the effects of coal seam moisture and temperature variations, it has been concluded that results displayed an obvious decrease in CO2 sorption ranging from sub-critical to supercritical pressures overall. The decrease in CO2 sorption was as much as 77% from dry (0%) to the maximum moisture simulated value of ~4.4%. Sorption decreased almost linearly for every 1% of coal moisture increase, until the maximum coal saturation was approached at around 4%. Sorption results relating to increased temperature also displayed an inverse relationship, and hence lower overall CO2 sorption capacities were calculated. The heats of adsorption for these coals were found to be between 21.9 and 39.9 kJ/mol confirming the nature of adsorption to be physical. Results confirm that the calculated heat of adsorption (KJ/mol) and the adsorption capacity (mmol/g) are positively correlative. For investigations pertaining to CH4 desorption for CH4 saturated simulated coals (CH4 added to and then removed from coal samples due to the unavailability of freshly cored coal samples), it was observed that CO2 uptake by pressurized injection for low - high pressures certainly enhances CH4 desorption rate. Results revealed that incremental CO2 injection pressures yielded higher CH4 desorption rates, for both the HRC and MRC coals. Generally there was an observed increase in the rate of CH4 desorbed for all coals tested at 55 oC as compared to 35 oC. This can as well be attributed to the fact that the increase in temperature causes the adsorbed CH4 molecules to vibrate more due to the increased kinetic energy of the molecules. This consequently leads to ease of desorption when CO2 is pumped under pressure into the coal structure, which clearly favours ECBM potentials. Some very good findings have been highlighted in the thesis from a SA coal perspective, and certainly serve as a very good starting point for further investigations pertaining to CO2, CH4, and coal interactions. However, from the vast literature already published globally, it can be seen that much more needs to be done in terms of addressing coal-CO2-CH4 research from a SA perspective, and indeed CCS in SA in general. It is apparent that the results and sum of the key findings presented in this thesis, are of importance for the selectivity and technical modelling for CO2 onshore coalbed storage and ECBM projects to be implemented in SA in the near future so as to meet the demands required to reduce CO2 emissions in SA as part of the global community. / PH2020

Sequestration has been suggested as a solution for resolving the problem of increasing greenhouse gas emissions. CO2 is the major greenhouse gas which results from using fossil fuels for domestic and industrial purposes. Different geological targets have been suggested as reservoirs for CO2 sequestration with saline aquifers being the focus of this research. Monitoring and verification of injected CO2 into the ground is an essential part of CO2 sequestration because there is a strong requirement to understand and correctly manage the CO2 flow and movement within the reservoir over time. This includes a need to understand mobile CO2 in its all phases (gas, liquid, supercritical and dissolved in formation water). It is now well recognised that monitoring injected liquids in the sub-surface can be done remotely using surface seismic monitoring techniques. Seismic waves are sensitive to the contrast in the physical properties of formation water and CO2. As a gas, the migration path of CO2 has been shown to be easily imaged but such images provide only a qualitative rather than a quantitative solution, which is inadequate to remotely verify storage volumetrics. The complexity of saline aquifer reservoirs containing the different phases of CO2 (a function of reservoir pressure, temperature, and chemical composition and the state of phase of injected CO2) requires a good knowledge base of how the seismic response changes to such changes in CO2 phase and reservoir heterogeneities for verification purposes. / In this research, transmission ultrasonic seismic experiments were performed under controlled pressure, temperature and CO2 dissolution conditions in water. Different forms of simulated rock matrix were used to understand how seismic attributes changed with changing sequestration conditions. Data analysis showed that the commonly used approach of seismic velocity analysis is not particularly sensitive to dissolved CO2 whereas seismic amplitude was very sensitive to dissolved CO2 content and is the seismic attribute of choice for the future quantification of CO2. The density increase in formation water brine as a result of CO2 mixture was found to be directly related to transmission amplitude and provides the potential for prediction and thus, remote quantification. Also, there was confirmation during the transmission experiments that seismic amplitude changes markedly when CO2 changes phase from its dissolved form into a gas, as a result of significant attenuation by CO2 bubbles. Analysis showed that the dominant and centre frequency of the spectra also responded to CO2 phase when it changed from dissolved to its free gas form. However, these attributes appear to be of use in a qualitative manner rather than quantitative. The CO2 pre-bubble phase was studied in an attempt to obtain a basic knowledge of the effect on seismic amplitude variation for quantifying dissolved gas amounts with some success. This knowledge has an application in Gas-to-Oil-Ratio mapping in depleting oil fields and can assist the future management of production from fields which are at the stage of near-bubble point due to pressure depletion. / The results of this research have an application in time-lapse seismic monitoring and operational management of greenhouse gas sequestration operations. In particular, the VSP and cross-well seismic methods are immediate beneficiaries of this research, with further work required for application to 3-D reflectivity methods in time-lapse surface seismic monitoring.

Thesis--Auburn University, 2009. / Abstract. Includes bibliographic references (p.71-87).

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: John Antle. Includes bibliographical references (leaves 70-74).