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.

An approach to predictions of position and size of hydrate plugs inside gas wells has been proposed. It is based on the mathematical model of steady non-isothermal flow of real gas in tubes and an algorithm of calculation of equilibrium conditions of hydrate formation. The proposed approach includes the following steps. 1) Numerically solve the system of ordinary differential equations to find the distributions of pressure and temperature along a particular well. 2) Represent the results of calculations as connection between pressure and temperature. 3) Find the intersection of this function with the calculated or experimental equilibrium curve for a particular natural gas. 4) Find the depth of well from the results of numerical solution.

The production of cyanobacterial biofilm biomass and phycocyanin from Rotating Algal Biofilm Reactors utilizing undiluted produced water from oil and natural gas extraction as a culture medium was investigated in this study. Produced water is the largest waste stream generated by the oil and natural gas industries and represents a large volume of non-potable water that may be available for algae culture with minimal impact on freshwater resources. Combining the use of produced wastewater as culture medium with the production of high value algal pigments, such as phycocyanin, may increase the economic viability of algae culture and wastewater purification. High value phycocyanin pigment production and methods to increase phycocyanin yields with light limitation were examined in this study. A unique cyanobacteria species was isolated from the Logan City Wastewater Treatment Facility in Logan, Utah and used in conjunction with the Rotating Algal Biofilm Reactor platform for the duration of this study. Between the “high” and “low” light treatments used in this study, the high light treatment showed nearly twice the biomass production as the low light culture (4.8±0.7 vs. 2.7±0.4 g/m2-day). The low light biomass contained 87.6% more of the phycocyanin pigment, with a 230% increase in purity, then the biomass from the high light treatment. The areal footprint productivity of phycocyanin per day was the same for both the light treatments. An evaluation of growth attachment materials was conducted with cotton rope and cotton conveyer cloth materials found to be the most durable and having the highest yields of harvestable biomass. The cotton rope and cotton conveyor cloth materials were evaluated on a floating Rotating Algal Biofilm Reactor operating in a 2000 L outdoor produced water pond. The cotton rope yielded a 140% increase in biomass vs. the cotton cloth although the compositions varied greatly. The cotton cloth biomass was composed of mainly healthy algae with higher phycocyanin yields while the cotton rope showed a higher proportion of non-algae organisms and little phycocyanin. These results show promise for the utilization of produced water to grow cyanobacteria biofilms with modifiable biomass characteristics as a source of high value phycocyanin pigments.

No description available.

Thesis (MA)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Since its arrival onto the U.S. energy scene in the early 2000s, shale gas has had a significant impact on the global energy market. The fact that the shale gas supply of a single country has had such a widespread influence on the global energy market hints at the power that this energy resource holds as a ‘game changer’. With the fifth largest estimated shale gas reserves in the world, South Africa now faces the challenge of developing its own shale gas resources in the Karoo Basin. Having lifted the moratorium on hydraulic fracturing in September 2012, the South African government has indicated its interest in pursuing the commercial extraction of the country’s estimated shale gas reserves. This comes in light of the country’s potential energy crisis, as well as an increased role for natural gas in the country’s energy mix. South Africa has no history of shale gas extraction and currently has no legislation or regulatory practices in place to deal specifically with shale gas and hydraulic fracturing. The South African government thus faces the challenge of drawing policy lessons from other experienced shale gas-producing nations, such as the U.S., to close these regulatory gaps and exploit its national shale gas resources in an environmentally and economically responsible way. Consequently, this thesis focuses on the regulation of the American shale gas industry by asking what policy lessons the South African government can draw from the United States of America on its regulation of shale gas extraction. Richard Rose’s lesson-drawing approach to policy learning was adopted as the theoretical framework for this study and can also be applied as an analytical tool to aid in data collection and data analysis. Furthermore, the framework was operationalised through the research methods used for this case study, which consisted of a review of literature on the U.S. regulation of shale gas extraction. This research produced a number of key findings in the form of policy lessons for South Africa. Four main policy lessons were drawn on the regulation of shale gas extraction: regulation of shale gas extraction must occur at all levels of government—national, provincial and local; policy research must be used to inform policymaking for the development of new legislation specific to shale gas and hydraulic fracturing, so as to avoid regulatory exemptions often linked to ad hoc policymaking on shale gas extraction; each level of government and their related regulatory agencies must have clearly defined regulatory roles relating to shale gas and hydraulic fracturing; and finally, there must be uniformity in terms of the regulatory focus of shale gas regulators at all levels of government. / AFRIKAANSE OPSOMMING: Sedert skaliegas vroeg in die jare sedert 2000 op die Amerikaanse energietoneel verskyn het, het dit ‘n beduidende impak op die globale energiemark gehad. Die feit dat die voorraad skaliegas van een land so ‘n wydverspreide invloed gehad het op die globale energiemark is ‘n aanduiding van die mag van hierdie energiebron as ‘n spel-wisselaar.Suid-Afrika het die vyfde-grootste skaliegasreserwes ter wêreld, en staan nou voor die uitdaging om sy eie skaliegasreserwes in die Karookom te ontwikkel. Nadat die moratorium op hidrobreking in September 2012 opgehef is, het die Suid-Afrikaanse regering aangedui dat hulle belangstel om die land se beraamde skaliegasreserwes kommersieel te ontgin. Dit het ontstaan in die lig van die potensiële energiekrisis wat Suid-Afrika in die gesig staar, asook die begeerte dat aardgas ‘n groter rol moet speel in die land se mengsel van energiebronne. Suid-Afrika het geen geskiedenis van skaliegasontginning nie en tans is daar geen wetgewing of regulerende praktyke in plek wat spesifiek te make het met skaliegas en hidrobreking nie. Die Suid-Afrikaanse regering staan dus voor die uitdaging om te leer uit die beleidsrigtings van ander ervare skaliegaslande soos die V.S.A. ten einde hierdie leemtes in regulering op te hef en sy nasionale skaliegasreserwes op ‘n omgewingsvriendelike en ekonomies-verantwoordelike manier te ontgin. Gevolglik fokus hierdie tesis op die regulering van die Amerikaanse skaliegas-industrie deur te vra watter beleidslesse die Suid-Afrikaanse regering kan leer by die Amerikaanse regering oor die regulering van hulle skaliegasontginning. Richard Rose se 'lesson-drawing'-benadering tot die leer van beleid is aanvaar as die teoretiese raamwerk vir hierdie studie en kan ook aangewend word as 'n analitiese instrument om te help met dataversameling en -analise. Die raamwerk is verder geoperasionaliseer deur die navorsingsmetodes wat gebruik is vir hierdie gevallestudie, wat bestaan het uit 'n oorsig van die literatuur oor die V.S.A. se regulering van skaliegasontginning. Hierdie navorsing het ‘n aantal sleutelbevindinge opgelewer in terme van beleidslesse vir Suid-Afrika. Die vier vernaamste beleidslesse oor die regulering van skaliegasontginning wat na vore gekom het, is die volgende: die regulering van skaliegas moet op alle vlakke van regering geskied – nasionaal, provinsiaal en op plaaslike vlak; navorsing oor beleid moet gebruik word om beleidsvorming in te lig sodat nuwe wetgewing ontwikkel kan word wat spesifiek gerig is op skaliegas en hidrobreking, ten einde uitsonderings op regulering te voorkom wat dikwels verbind word met ad hoc beleidsformulering; elke vlak van regering en sy verwante reguleringsagentskappe moet duidelik gedefinieerde reguleringsrolle hê ten opsigte van skaliegas en hidrobreking; en, ten slotte, daar moet eenvormigheid wees in die reguleringsfokus van skaliegasreguleerders op alle vlakke van regering. / National Research Foundation (DAAD-NRF)

I Sverige finns uppskattningsvis mellan 4000 och 8000 stycken deponier. De flesta av deponierna är nedlagda och år 2001 fanns det 142 stycken aktiva deponier för hushållsavfall. År 2010 hade antalet minskat till 76 stycken.  Vid nedbrytning av organiskt material i deponier bildas metanhaltig deponigas som bidrar till växthuseffekten. Utsläppens omfattning prognostiseras med hjälp av beräkningsmodeller, exempelvis IPCCs. Dessa modeller fordrar att antaganden görs av exempelvis andelen gas som utvinns via gasuppsamlingsutrustningen, det organiska materialets halveringstid och avfallets sammansättning och mängd. I Sverige görs antagandet att 60 procent av deponigasen samlas upp på deponier med gasuppsamlingsutrustning. Rapportens övergripande syfte var att undersöka hur osäkerheterna i de antaganden som görs kan inverka på de prognostiserade deponigasemissionerna. Syftet var också att bedöma om metangasutsläpp från deponier utgör ett stort eller försumbart tillskott av växthusgasutsläpp i jämförelse med andra källor. Detta gjordes genom en känslighetsanalys som baserades på en litteraturstudie, IPCC- prognostiserade metanmängder samt genom intervjuer med deponiägare.   Prognostiserad metangasproduktion från landets deponier jämfördes med uppskattad metangasproduktion, där det senare baserades på utvunna mängder i landet och en uppskattad utvinningsgrad på 60 procent. Prognostiserad metangasmängd jämfördes med en uppskattad mängd metan, där den senare baserades på utvunna gasmängder i landet och uppskattad utvinningsgrad. Omfattningen av emissionerna gjordes genom känslighetsanalys där utvinningsgrad hos gasuppsamlingssystemets varierades mellan 30 och 80 procent. De utvunna gasmängderna har varit relativt konstanta de senaste tio åren trots att antalet deponier med gasuppsamlingsutrustning minskat från 75 till 47 stycken och att deponeringsförbud har instiftats. Den antagna halveringstiden på 7,5 år torde därför vara för lågt ansatt vilket också styrks av den dåliga nedbrytningen i flera äldre deponier, minskade mängder deponerat avfall samt att inget organiskt material deponeras sedan 2005. Sveriges huvudsakliga metankällor är jordbrukssektorn och deponier från avfallssektorn. År 1990 var de prognostiserade utsläppen från de två sektorerna ungefär lika stora. Fram till år 2010 har de prognostiserade utsläppen från deponier halverats medan utsläpp från jordbruket ligger på ungefär samma nivå som tidigare.   Ur den enskilda deponins perspektiv kan det konstateras att utvinningsgraden hos gasuppsamlingssystemet varierar i både ett kortsiktigt och i ett långsiktigt perspektiv. Beroende på när en mätning utförs kommer en viss variation uppvisas i gasutvinningssystemets utvinningsgrad dvs både emitterade och uppsamlade gasmängder varierar mellan mättillfällena.  Det kan konstateras att en stor osäkerhet byggs in i den beräknade årsproduktionen av metangas när metanmängderna beräknas med hjälp av medelvärden från ett fåtal mätningar utförda under korta mätperioder. Statistiska Centralbyrån har gjort beräkningar av den årliga utvinningsgraden. Dessa beräkningar har grundats på faktiska utvunna mängder som jämförts med beräknade totala mängder. För en enskild deponi kan skillnaderna mellan de beräknade och faktiska mängderna vara stora vilket medför att utvinningsgraden eller produktionen är svårbedömd både för den enskilda deponin och på nationell nivå.   Potentialen för gasutvinning i deponier bedöms i det här examensarbetet vara större än vad som har prognostiserats. Perioden för gasuttag sträcker sig längre än vad man trott med anledning av att mycket av det organiska materialet i gamla deponier fortfarande inte har brutits ner, samt att gasproduktion fortfarande sker. Med anledning av de låga driftskostnaderna bör deponigasutvinning fortskrida så länge som det är tekniskt möjligt och ekonomiskt hållbart. Genom provtagningar av avfallet i kombination med mätningar som sträcker sig över längre perioder, skulle bättre kännedom om metangasproduktionen i deponier kunna fås. / There are a large number of landfill sites in Sweden. The total number is estimated to be somewhere between 4000 to 8000 landfills. In 2007 there were 142 landfill sites still operating, three years later the number of operating landfills decreased to 76. The municipalities are at present carrying out an inventory of old landfill sites in Sweden. The focus is on the location and risk classification of the landfill sites. There is a substantial uncertainty of the content and the progress of the degradation process unless the landfill is dug out. Methane containing landfill gas is produced when the organic matter in the waste is degraded. Since methane is a potent green house gas the emissions of landfill gas will contribute to the green house effect.   The extent of the emissions is usually quantified using the IPCC model or similar. The models require certain estimations to be made such as the amount of gas that is extracted, the half-life of the organic matter and the composition of the waste. The aim of the report was therefore to look into these estimations and how these can effect the landfill gas production. The aim was also to evaluate whether the methane emissions from landfills is a major contributor to the green house gas emissions in comparison to other sources. The master thesis has been carried out through a literature study and interviews with landfill owners that resulted in a sensitivity analysis.     The plausibility of the IPCC model was studied by carrying out a sensitivity analysis of the efficiency of the gas extraction system and how this will influence the total emissions of landfill gas.  An overview of the connection between the land fill gas production and the decomposition of the organic matter could be realized by analyzing the material in the landfill through tests on different depths in the landfill when drilling new gas wells. The extracted amounts of landfill gas are also contradictive to the estimation of the half-life of 7,5 years that is assumption regularly made within the IPCC- model. This theory is supported by the inadequate decomposition of organic material in old landfill sites. The reduced amounts of waste that is landfilled and the prohibition of landfilling of organic and combustible waste in 2005 are also supporting this theory. The main methane sources in Sweden are ruminants from the agricultural sector and landfills. In 1990 the forecast of the methane emissions of the two sectors were equal. The forecast of today shows that the agricultural emissions are more or less the same but the emissions from landfill are halved.   Another conclusion was that the efficiency of the gas extraction is varying in a short- term and in a long-term perspective. Depending on when a measurement is carried out there will be a variation of the efficiency of the gas extraction system. Anyhow annual values of the extracted amounts are calculated based on a few occasional measurements over very short time periods.  Moreover, the yearly efficiency is determined based on real extracted values of methane and calculated total values of methane production that are non-comparable.   The potential of gas extraction is probably larger than what has been predicted and the period of gas extraction is probably longer than expected. Supported by the low operation costs for the gas extraction the extraction should be carried out as long as it is technically possible and economically reasonable.  Analyzing the material in the landfill site will increase the understanding of the gas production and the degradation of the waste in the landfill.

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Esta dissertação apresenta um estudo ergonômico sobre o trabalho de operadores de processo de plataformas marítimas de produção de petróleo. As primeiras investigações sobre as atuais práticas e produtos finais de projetos de sistemas produtivos de grande porte resultaram em indícios de um ambiente de produção com aspectos operacionais não equilibrados e desintegrados. A partir destes indícios, foi realizada uma revisão bibliográfica que destacou as considerações e limitações de aspectos relacionados à Ergonomia em assuntos como gestão de projetos, projetos de engenharia, de sistemas produtivos e de arranjo físico. A revisão relativa à Ergonomia destacou seus conceitos básicos, a Ergonomia de Concepção e estudos relacionados ao trabalho de operadores de produção contínua, tendo o objetivo de indicar possibilidades de atuações desta ciência em projetos de plantas produtivas. Desta forma, a pesquisa de campo desenvolvida procurou destacar aspectos operacionais como dificuldades e constrangimentos enfrentados pelos operadores. Tais aspectos foram investigados com o objetivo de ressaltar os desequilíbrios presentes nesta situação de trabalho e as estratégias desenvolvidas por estes operadores para manterem o funcionamento satisfatório da unidade produtiva, atendendo aos objetivos da organização empresarial em que se inserem. / This work presents the ergonomics study based on offshore oil production platforms, in operation works for the process plant. The first investigations resulted on indications of disintegrated and unbalanced operational aspects into the production environment. From those evidences, the bibliographical revision indicated the considerations and limits of aspects related to Ergonomics in subjects as design management, engineering design, productive systems and layout design. The revision of Ergonomics included basic concepts, Ergonomics of Conception, and studies related to the operator works of continuous production process, having the aim of indicating participation possibilities of this science in production plants design. In such a way, the developed research tried to raise operational aspects as difficulties and constraints daily faced by operators. Such aspects were investigated intending to stand out the disequilibriums in this situation of work and strategies developed by these operators to keep satisfactory performance of a productive unit, taking care of company goals where they are inserted.

This thesis provides a comparative analysis of the environmental values present in Ghana’s and Senegal’s coastal regions, and the implications that those have for the surrounding environment. The countries approaches to urban farming, mining and oil and gas extraction, fishing, marine debris and municipal waste management are assessed in order to reach a greater understanding of these environmental issues. In undertaking this thesis, I attempted to draw a correlation between the handling of these issues and how people perceive their environment. Through the comparison of environmental degradation and the level of effort to achieve a more sustainable developmental framework in both countries, I draw examples from successes in Senegal’s coastal management framework to recommend appropriate environmental policy for the Greater Accra Region.