Global ETD Search

11	Bringing fuel cells to reality and reality to fuel cells : A systems perspective on the use of fuel cells Saxe, Maria January 2008 (has links) With growing awareness of global warming and fear of political instability caused by oil depletion, the need for a society with a sustainable energy system has been brought to the fore. A promising technology often mentioned as a key component in such a system is the fuel cell technology, i.e. the energy conversion technology in focus in this thesis. The hopes and expectations on fuel cells are high and sometimes unrealistically positive. However, as an emerging technology, much remains to be proven and the proper use of the technology in terms of suitable applications, integration with society and extent of use is still under debate. This thesis is a contribution to the debate, presenting results from two fuel cell demonstration projects, looking into the introduction of fuel cells on the market, discussing the prospects and concerns for the near-term future and commenting on the potential use in a future sustainable energy system. Bringing fuel cells to reality implies finding near-term niche applications and markets where fuel cell systems may be competitive. In a sense fuel cells are already a reality as they have been demonstrated in various applications world-wide. However, in many of the envisioned applications fuel cells are far from being competitive and sometimes also the environmental benefit of using fuel cells in a given application may be questioned. Bringing reality to fuel cells implies emphasising the need for realistic expectations and pointing out that the first markets have to be based on the currently available technology and not the visions of what fuel cells could be in the future. The results from the demonstration projects show that further development and research on especially the durability for fuel cell systems is crucial and a general recommendation is to design the systems for high reliability and durability rather than striving towards higher energy efficiencies. When reliability and durability are achieved fuel cell systems may be introduced in niche markets where the added values presented by the technology compensate for the initial high cost. / QC 20100909 / Energy Systems Programme / Clean Urban Transport for Europe / GlashusEtt Assessment CUTE Demonstration projects Emerging technology Evaluation Fuel cell buses Fuel cell systems Fuel cells Hype Interdisciplinary Niche markets PEM Radical technologies SOFC Strategic niche markets Sustainability Chemical energy engineering Kemisk energiteknik
12	Towards sustainable urban transportation : Test, demonstration and development of fuel cell and hybrid-electric buses Folkesson, Anders January 2008 (has links) Several aspects make today’s transport system non-sustainable: • Production, transport and combustion of fossil fuels lead to global and local environmental problems. • Oil dependency in the transport sector may lead to economical and political instability. • Air pollution, noise, congestion and land-use may jeopardise public health and quality of life, especially in urban areas. In a sustainable urban transport system most trips are made with public transport because high convenience and comfort makes travelling with public transport attractive. In terms of emissions, including noise, the vehicles are environmentally sustainable, locally as well as globally. Vehicles are energy-efficient and the primary energy stems from renewable sources. Costs are reasonable for all involved, from passengers, bus operators and transport authorities to vehicle manufacturers. The system is thus commercially viable on its own merits. This thesis presents the results from three projects involving different concept buses, all with different powertrains. The first two projects included technical evaluations, including tests, of two different fuel cell buses. The third project focussed on development of a series hybrid-bus with internal combustion engine intended for production around 2010. The research on the fuel cell buses included evaluations of the energy efficiency improvement potential using energy mapping and vehicle simulations. Attitudes to hydrogen fuel cell buses among passengers, bus drivers and bus operators were investigated. Safety aspects of hydrogen as a vehicle fuel were analysed and the use of hydrogen compared to electrical energy storage were also investigated. One main conclusion is that a city bus should be considered as one energy system, because auxiliaries contribute largely to the energy use. Focussing only on the powertrain is not sufficient. The importance of mitigating losses far down an energy conversion chain is emphasised. The Scania hybrid fuel cell bus showed the long-term potential of fuel cells, advanced auxiliaries and hybrid-electric powertrains, but technologies applied in that bus are not yet viable in terms of cost or robustness over the service life of a bus. Results from the EU-project CUTE show that hydrogen fuelled fuel cell buses are viable for real-life operation. Successful operation and public acceptance show that focus on robustness and cost in vehicle design were key success factors, despite the resulting poor fuel economy. Hybrid-electric powertrains are feasible in stop-and-go city operation. Fuel consumption can be reduced, comfort improved, noise lowered and the main power source downsized and operated less dynamically. The potential for design improvements due to flexible component packaging is implemented in the Scania hybrid concept bus. This bus and the framework for its hybrid management system are discussed in this thesis. The development of buses for a more sustainable urban transport should be made in small steps to secure technical and economical realism, which both are needed to guarantee commercialisation and volume of production. This is needed for alternative products to have a significant influence. Hybrid buses with internal combustion engines running on renewable fuel is tomorrow’s technology, which paves the way for plug-in hybrid, battery electric and fuel cell hybrid vehicles the day after tomorrow. / QC 20100722 acceptance analysis auxiliary system bus Clean Urban Transport for Europe concept CUTE demonstration driver drive cycle duty cycle energy flow evaluation fuel cell heavy duty vehicle hybrid management hybrid vehicle hydrogen passenger PEM safety Sankey diagram series hybrid sustainable test urban transport vehicle simulation acceptans analys hjälpaggregat buss Clean Urban Transport for Europe koncept CUTE demonstration körcykel förare energiflöde utvärdering bränslecell tunga fordon hybridsystemkontroll hybridfordon vätgas passagerare PEM säkerhet Sankey-diagram seriehybrid uthållig hållbar test stadstransport fordonssimulering Vehicle engineering Farkostteknik Chemical engineering Kemiteknik
13	Perceptions Of Cuteness And Beauty Jones, Danielle 01 January 2009 (has links) Upbringing and psychological make-up inspire individual norms for beauty and cuteness. The mannerist approach in my work is a product of the figural liberties found in cartooning, illustration and art history. By altering facial and bodily features, I relate the proportions of an infant to cuteness and innocence. However, I tailor the photographs to empower the subjects all the while mirroring trends in contemporary pop culture. I'm interested in themes of everyday life, vitality and emotion placed in obscure, imaginary or exaggerated venues. I fictionalize subjects of my reality to compel viewers to identify with and fancy emotions, circumstances, moods and relationships. The intent is to amplify, yet be truer to their existence and idiosyncrasies through figural adaptations. art artist digital painting digital painting photography manipulated photography cute cuteness beauty caricature quaint quaintness vintage mfa fine art fine arts illustration mannerist mannerism symmetry golden ration kawaii krutt pedagogy jocose transmogrification color quintessential character characteristics physiognomy proportions proportion infant idiosyncrasy idiosyncrasies idiosyncratic relationships norms facial face features innocence vulnerability empowering empower cartoon cartooning anime manga Art and Design

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