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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

MODIFICATION OF A CURRENT COALBED METHANE PERMEABILITY MODEL FOR HORIZONTAL STRAIN ONLY

Schrader, Sawyer David 01 August 2018 (has links)
Cleat permeability of coal is the most critical parameter affecting the amount of production from a coalbed methane (CBM) reservoir. As a result, there have been many studies about how cleat permeability changes over the life of a reservoir, leading to the development over time of several different permeability models. Most permeability models used today consider volumetric strain as an input parameter; however, permeability is impacted primarily by the increase in cleat aperture, resulting from matrix shrinkage in the horizontal direction. Recent work has shown that coal exhibits transverse isotropy, with total strain in the vertical direction being significantly higher than either horizontal direction. Hence, the inclusion of vertical strain through use of the volumetric strain parameter could be predicting inaccurate permeability variation results. The objective of this study was to determine the difference in permeability modeling with volumetric strain compared to permeability modeling with only horizontal strain, and assess the degree to which different parameters affect results from modeling using only horizontal strain. Experimental results showed that matrix strain remained consistent with transversely isotropic results of previous works. When included into the Palmer and Mansoori (P&M) permeability model, modeling results showed that permeability with horizontal strain is significantly lower than that with volumetric strain. The three unmeasured parameters in the Palmer and Mansoori permeability model have a major effect on the final results and need to be history matched in order to improve the level of accuracy in their estimation.
2

Re-scaling Governance: First Nations and the Challenge of Shale Gas Development in British Columbia

Murray, Mathew 03 September 2015 (has links)
The government of British Columbia faces a host of challenges as it attempts to establish a liquefied natural gas export industry and reignite unconventional shale gas production in northeast BC. Not only must it contend with a competitive and saturated global marketplace, but it must also address conflict with Treaty 8 First Nations whose treaty rights and traditional territories were impacted by early development. Shale gas impacts are intensely local, but First Nations have struggled to gain meaningful influence in colonial decision-making processes to ensure development decisions respect community values and authority. This research, conducted in partnership with Fort Nelson First Nation, explores the challenges and opportunities faced by the Nation in their efforts to reshape governance of the shale gas industry in their territory to address its environmental impacts. The research is situated within a review of multiple literatures including political economy, Indigenous governance, and critical studies of natural resource governance, social conflict and co-management in Indigenous-settler contexts. Through interviews and participant observation with the Fort Nelson First Nation, the thesis documents how those involved in shale gas governance at the local level perceive existing processes, and investigates under what conditions a more localized governance might resolve shale gas conflict in northeast BC. It develops an argument that shale gas governance must be rescaled to address landscape scale impacts and enhance the authority of local First Nations interests and knowledge. While collaborative governance reforms like co-management may not wholly eliminate deeply seated colonial authority, they can be effective and empower local First Nations communities under certain conditions. However, this case poses a unique set of context-specific challenges to governance reform, which the Fort Nelson First Nation are confronting as they work towards their governance and land use goals for their traditional territory. As the Nation continues to move forward, it is uncertain how they will negotiate the non-renewable industry’s political economy, and the current pro-development shale gas politics in BC. As such, this case offers a rare lens into local community experience with this relatively new and contentious global energy industry. / Graduate
3

Model mikro sítě s akumulací / Model of microgrid with energy storage

Halás, Andrej January 2015 (has links)
This thesis describes the operation , characteristics and operating conditions of microgrid with energy storage , provides insight into the benefits of using listed concepts . The first part deals with the description of microgrid systems, distribution and shows examples of its use. The second part describes individual elements of the storage systems, energy production and energy transformation used in microgrids . The third part describes the work with PSCAD software. The main goal is to design a micro grid model in PSCAD and validate its function.
4

Stirlingův termodynamický cyklus / The Stirling Thermodynamic Cycle

Macháček, Jan January 2009 (has links)
My doctoral thesis deals with study and analyse of Stirling thermodynamical cycle. Cycle that is composed of two isochoras and two isotherms. I describe functional principle of Stirling engine and all its parts, constructional variations of pistons system and possible engine working modes. Next chapter contains analyse of engine constructional parameters. Measuring of torque and load characteristics, p - V schemes and output work for various engine inputs is part of this analyse. There is composed mathematical engine characterization by means of Schmidt theory in chapter five. Mathematical characterization is consequently applied to engine model. Theoretical analysis and practical measurement were base for concepts, realization and verification of constructional correction. One part of my thesis is attended to design of new lamella for regenerative exchanger. For optimal lamella constructional proportions were used computational algorithm and simulations. There is concept of cogeneration unit with Stirling engine and its benefits check in last chapter. General theoretical and practical analyse of workable Stirling engine is result of my thesis. Analyse in this extent was not nowhere publishing yet. Design of regenerative exchanger lamella is then practical input of my thesis.
5

Frontiers of Fracking : Underground Political Ecology and Unconventional Energy in the Contested Landscapes of North West England

Clifford, Joseph January 2015 (has links)
Gas obtained from previously unexploited shale rock strata has emerged as an economically viable way of sourcing additional fossil fuel energy resources after the so-called ‘shale gas revolution’ in the United States. In the United Kingdom, the incumbent government has committed to the development of its own shale gas resources. A highly polarised public debate has erupted on the risks and rewards of extracting the shale gas deposits that presently lie underneath large swathes of the country using the controversial method of hydraulic fracturing, or ‘fracking’. This thesis examines how different groups in North West England – the major frontier of fracking in the UK – are contesting, resisting and negotiating the current government’s decision to sanction and push ahead towards the development a domestic shale gas industry. Employing a theoretical framework drawn from political ecology as its core mode of examination, this thesis utilises qualitative methods including in-depth interviews and participant observation techniques. It documents a range of social groupings that are contesting shale gas in the UK in a number of ways, and argues that landscapes and risk are fundamental hinges in this ongoing environmental conflict.

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