Started as an EOR technique to produce oil, injection of carbon dioxide which is essentially a greenhouse gas is becoming more and more important. Although there are a number of mathematical modeling studies, experimental studies are limited and most studies focus on injection into sandstone reservoirs as opposed to carbonate ones. This study presents the results of computerized tomography (CT) monitored laboratory experiments to characterize relevant chemical reactions associated with injection and storage of CO2 in carbonate formations. Porosity changes along the core plugs and the corresponding permeability changes are reported for varying CO2 injection rates, temperature and salt concentrations. CT monitored experiments are designed to model fast near well bore flow and slow reservoir flows. It was observed that either a permeability improvement or a permeability reduction can be obtained. The trend of change in rock properties is very case dependent because it is related to distribution of pores, brine composition and as well the thermodynamic conditions. As the salt concentration decreased the porosity and thus the permeability decrease was less pronounced. Calcite scaling is mainly influenced by orientation and horizontal flow resulted in larger calcite deposition compared to vertical flow. The duration of CO2 &ndash / rock contact and the amount of area contacted by CO2 seems to have a more pronounced effect compared to rate effect. The experiments were modeled using a multi-phase, non-isothermal commercial simulator where solution and deposition of calcite were considered by the means of chemical reactions. The calibrated model was then used to analyze field scale injections and to model the potential CO2 sequestration capacity of a hypothetical carbonate aquifer formation. It was observed that solubility and hydrodynamic storage of CO2 is larger compared to mineral trapping.

Progress in the microelectronics industry is driven by smaller and faster transistors. As feature sizes in integrated circuits become smaller and liquid chemical waste becomes an even greater environmental concern, gas expanded liquids (GXLs) may provide a possible solution to future device fabrication limitations relative to the use of liquids. The properties of GXLs such as surface tension can be tuned by the inclusion of high pressure gases; thereby, the reduced surface tension will allow penetration of cleaning solutions into small features on the nanometer scale. In addition, the inclusion of the gas decreases the amount of liquid necessary for the photoresist and etch residue removal processes. This thesis explores the role of CO2-based GXLs for photoresist and etch residue removal. The gas used for expansion is CO2 while the liquid used is methanol. The cosolvent serving as the removal agent is tetramethyl ammonium hydroxide (TMAH) which upon reacting with CO2 becomes predominantly tetramethyl ammonium bicarbonate (TMAB).

Australia is recognising that carbon capture and storage (CCS) may be a feasible pathway for addressing increasing levels of CO2 emissions. This thesis presents a preliminary economic assessment and comparison of the capture costs for different Australian CO2 emission sources. The capture technologies evaluated include solvent absorption, pressure swing adsorption (PSA), gas separation membranes and low temperature separation. The capture cost estimated for hydrogen production, IGCC power plants and natural gas processing is less than A$30/tonne CO2 avoided. CO2 capture cost for iron production ranges from A$30 to A$40 per tonne CO2 avoided. Higher costs of A$40 to over A$80 per tonne CO2 avoided were estimated for flue gas streams from pulverised coal and NGCC power plants, oil refineries and cement facilities, and IDGCC synthesis gas. Based on 2004 and 2005 EU ETS carbon prices (A$30 to A$45 per tonne CO2 avoided), the cost of capture using current commercially available absorption technology may deter wide-scale implementation of CCS, in particular for combustion processes. A sensitivity analysis was undertaken to explore the opportunities for reducing costs. The high cost for capture using solvent absorption is dependent on the energy needed for solvent regeneration and the high capital costs. Cost reductions can be achieved by using new low regeneration energy solvents coupled with recycling the waste heat from the absorption process back to the steam cycle, and using low cost ???fit-for-purpose??? equipment. For membrane and PSA technologies, the capture costs are dominated by the flue gas and post-capture compressors. Operating the permeate or desorption stream under vacuum conditions provides significant cost reductions. Improvements in membrane and adsorbent characteristics such as the adsorbent loading or membrane permeability, CO2 selectivity, and lower prices for the membrane or adsorbent material provide further cost benefits. For low partial pressure CO2 streams, capture using low temperature ???anti-sublimation??? separation can be an alternative option. Low costs could be achieved by operating under low pressures and integrating with external sources of waste heat. Applying the cost reductions achievable with technology and process improvements reduces the capture and CCS costs to a level less than current carbon prices, making CCS an attractive mitigation option.

Maintenance of normal health requires an intact stress system capable of mounting the metabolic, autonomic, behavioural and motor responses required for coping with or avoiding physiological and pathological challenges. The neuroendocrine component of this response principally involves the hypothalamic-pituitary-adrenal (HPA) and sympatho-adrenomedullary (SAM) axes. Impaired regulation of these axes has been implicated in the pathogenesis and expression of numerous disease states, however, it has proved very difficult to reproducibly activate the HPA and SAM axes and no single test exists that can reliably and safely be used to study these systems in man. Carbon dioxide (CO2) is the principal regulator of respiration, acid-base balance and behavioural-state arousal in humans. Paradigms of CO2 inhalation have been used in psychiatric research to investigate panic and anxiety disorders, but evaluation of other components of the stress response to CO2 has not previously been performed. I hypothesised that a single breath of 35% CO2 would be a simple and reliable tool for the evaluation of the stress response in humans. A single breath of four doses of CO2 (5%, 25%, 35% and 50%) was administered to 9 healthy volunteers in a randomised, single blind fashion. Subjective symptoms of anxiety increased in a dose-dependent manner. Inhalation of a single breath of 35% CO2 stimulated significant ACTH (p = 0.006), noradrenaline (p < 0.0001), cortisol (p = 0.02) and prolactin (p = 0.002) release. It also provoked an acute pressor response and an associated bradycardia (p < 0.0001 for both). No significant habituation of psychological, HPA or cardiovascular responses was seen when this dose was repeated after one week (n = 10) or 6 months (n = 5). It was apparent that a single breath of 35% CO2 reliably and safely produced SAM and HPA axis activation and further studies were then undertaken to assess the mechanism by which the observed responses occurred and its potential clinical implications. Administration of naltrexone (an opiate antagonist) to 10 normal volunteers disinhibited the HPA axis (p < 0.0004), whilst administration of metyrapone (a cortisol synthesis inhibitor) significantly reduced baseline cortisol (p < 0.03) levels. However, this alteration in HPA axis activity had no effect on either cardiovascular or psychological responses. Further, in a study of 8 breastfeeding mothers (a state associated with physiological suppression of the HPA axis) suckling significantly reduced plasma cortisol levels compared with control (p = 0.002) and bottle-feeders (p = 0.003). Despite this cortisol, systolic blood pressure (SBP), heart rate and psychological responses to 35% CO2 were not affected

Thesis (Ph. D.)--University of Sydney, 2000. / Title from title screen (viewed February 12, 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Biological Sciences, Faculty of Science. Degree awarded 2000; thesis submitted 1999. The 2 in the title is in subscript. Includes bibliographical references. Also available in print form.

Thesis (doctoral)--Universiteit Utrecht, 2008. / Includes bibliographical references (p. 127-140).

Thesis(M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (p.103-108).

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (p. [228]-243).

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 185-195).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main greenhouse gases (GHG) are the nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2), whose atmosphere concentrations increased in an unprecedented rate since the Industrial Revolution. This work aim evaluates the GEE emissions of spring/summer season in different soil management systems located in the Planalto region of Rio Grande do Sul State. This work was carried out in a long term experiment (22 years), located at FUNDACEP research center under a Rhodic Hapludox soil. This research was split in two studies: the first had the objective of evaluated the CO2 short-term emissions (21 days) during the tillage systems activities and cropping establishment under conventional tillage (CT) and no-tillage (NT) using a dynamic camera (Flux Chamber 6400-09, Licor). The second study aim evaluate the three main GEE, during the period from October/2007 to January/2008 period, totalizing 101 days, including the activities of soil tillage, establishment and part of the corn and soybean growing stage, under CT, NT and NT with wheat residues (NT-w). In this study in the static camera method, 11 air samples were collected using syringe at 0, 15, 30 and 45 minutes after the closing of the camera. The concentration of GEE were analyzed by gaseous chromatography. In the first study, CT presented accumulated CO2 emission 42% higher than NT, and the main source of CO2 in CT was associated to the residue decomposition and the release of soil CO2, while the gas efflux in NT was associated to the decomposition of soil organic matter. In the second study, all of the tillage systems were N2O source, being higher in NT. For CH4, all of the tillage systems, in the average of the period were a sink of this gas, being higher in NT-w. In relation to CO2, all of the systems were a source of this gas, being higher in CT and it was verified a seasonal effect in CO2 emissions, being higher in spring/summer seasons. The mitigation of the GEE emissions would be achieved by applying conservation tillage systems, with low soil disturbance, and rationalization in the mineral N fertilization. / Os principais gases de efeito estufa (GEE) são o óxido nitroso (N2O), metano (CH4) e dióxido de carbono (CO2), cujas concentrações na atmosfera aumentaram de forma sem precedentes desde a Revolução Industrial. Este trabalho teve como objetivo avaliar as emissões de primavera/verão de GEE em diferentes sistemas de manejo do solo no Planalto do Rio Grande do Sul. O trabalho, realizado em experimento de longa duração (22 anos), localizado na Fundação Centro de Experimentação e Pesquisa Fecotrigo (FUNDACEP), em Latossolo Vermelho, foi dividido em dois estudos: o primeiro avaliou as emissões de curto prazo (21 dias) de CO2 durante as atividades de preparo e implantação das culturas, em preparo convencional (PC) e plantio direto (PD), através de câmara dinâmica (Flux Chamber 6400-09, Licor); já o segundo foi uma avaliação conjunta dos três principais GEE, no período de outubro/2007 a janeiro/2008, totalizando 101 dias, abrangendo as atividades de preparo do solo, implantação e parte do desenvolvimento da cultura do milho e soja, em PC, PD e PD sobre resíduos de trigo (PD-t), através da realização de 11 coletas de amostras de ar pelo método da câmara estática, coletadas com seringa aos 0, 15, 30 e 45 minutos após o fechamento da câmara e a concentração dos GEE analisados por cromatografia gasosa. No primeiro estudo, o PC apresentou emissão acumulada dos 21 dias 42% superior ao PD, sendo que a principal fonte de CO2 no PC foi associada à decomposição dos resíduos e a liberação do CO2 retido no interior do solo, enquanto que no PD foi associada à mineralização da matéria orgânica do solo. No segundo estudo, todos os sistemas emitiram N2O, sendo maiores no PD. Quanto ao CH4, todos os sistemas, na média do período, oxidaram o gás, sendo maiores no PD-t. Em relação ao CO2, todos os sistemas emitiram o gás, sendo maior no PC e verificou-se haver uma sazonalidade em suas emissões, sendo mais elevada na primavera/verão. A mitigação das emissões de GEE passa pelo desenvolvimento de sistemas conservacionistas de manejo, com mínima perturbação do solo, e racionalização da adubação nitrogenada mineral.