82 resultados para progressive mesh


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A novel tubular cell structure for a direct methanol fuel cell (DMFC) is proposed based on a tubular Ti mesh and a Ti mesh anode. A dip coating method has been developed to fabricate the cell. The characterization of the tubular MEA has been analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), half cell and single cell testing. The tubular DMFC single cell comprises: a Ti mesh, a cathode diffusion layer and catalyst layer, a Nafion recast membrane and a PtRuO/Ti anode. Half cell tests show that the optimum catalyst loading, Ru/(Ru + Pt) atomic ratio and the Nafion loading of a PtRuO/Ti mesh anode are: 4 mg cm, 38% and 0.6 mg cm, respectively. Single cell tests show that the Nafion loading of the recast Nafion membrane and the concentration of the methanol in the electrolyte have a major influence on cell performance. © 2006 Elsevier B.V. All rights reserved.

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A novel anode structure based on Ti mesh for the direct methanol fuel cell (DMFC) has been prepared by thermal deposition of ~5 µm PtRuO2 catalyst layer on ~50 µm Ti mesh. The preparation procedures and the main characteristics of the anode were studied by half-cell testing, scanning electron microscopy analysis, energy-dispersive X-ray measurement, and single-cell testing. The optimum calcination temperature is 450°C, calcination time is 90- 120 min, PtRuO2 catalyst loading is 5.0 mg cm-2, Pt precursor concentration range of solution is 0.14- 0.4 M, and solution aging time is 1 day. The performances of the anodes prepared using the solution kept within 20 days showed no significant difference. When it was used in DMFC feed with low-concentration methanol solution at 90°C, this new anode shows better performance than that of the conventional anode, because its thin hydrophilic structure is a benefit to the transport of methanol and carbon dioxide. However, due to its opening structure, when higher concentration methanol was employed, the performance of the cell with new anode became worse. © 2006 The Electrochemical Society. All rights reserved.

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An anode structure based on Ti mesh has been developed for the direct methanol fuel cell (DMFC). This new anode was prepared by electrochemical deposition of a ~ 3 µ m PtRu catalyst layer on ~ 50 µ m Ti mesh. It has a thinner structure compared to that of a porous carbon-based conventional anode. The Ti mesh anode shows a performance comparable to, and exceeding that, of the conventional anode in a DMFC operating with 0.25 or 0.5 M methanol solution and atmosphere oxygen at 90 C. However, it shows a lower performance of the cell when higher concentrations of methanol was employed. This may be attributed to its thin and open structure, which could facilitate the transport of methanol from the flow field to the anode catalyst layer and carbon dioxide in the opposite direction. © 2006 International Association for Hydrogen Energy.

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Integrating analysis and design models is a complex task due to differences between the models and the architectures of the toolsets used to create them. This complexity is increased with the use of many different tools for specific tasks using an analysis process. In this work various design and analysis models are linked throughout the design lifecycle, allowing them to be moved between packages in a way not currently available. Three technologies named Cellular Modeling, Virtual Topology and Equivalencing are combined to demonstrate how different finite element meshes generated on abstract analysis geometries can be linked to their original geometry. Cellular models allow interfaces between adjacent cells to be extracted and exploited to transfer analysis attributes such as mesh associativity or boundary conditions between equivalent model representations. Virtual Topology descriptions used for geometry clean-up operations are explicitly stored so they can be reused by downstream applications. Establishing the equivalence relationships between models enables analysts to utilize multiple packages for specialist tasks without worrying about compatibility issues or substantial rework.

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The stress regime in a cutting (slope) is complex, with different principle stresses acting in different directions along the potential failure plane. For example, stresses may be primarily in extension near the toe and in compression near the crest of a slope. Cuttings in heavily overconsolidated clays are known to be susceptible to progressive failure which usually starts at the toe of the slope. Softening and the development of rupture surfaces have been observed in the field and are well documented for London Clays. However, this failure mechanism is yet to be established for glacial tills. To better understand the progressive failure mechanism, this paper discusses a series of laboratory tests conducted on reconstituted glacial till samples from Northern Ireland. Initial observations indicate that, a soil with insitu stress states between 80-90% of peak strength may undergo significant viscoplastic straining as a result of the combination of pore-pressure cycling and elevated stress level.

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The title of this short (about 4500 words) intervention translates to "To Nail a Jellyfish? Finding a progressive agenda for EU anti-discrimination law". I engage with those criticising EU anti-discrimination law as yet another emanation of the EU's "neo-liberal" nature which fails to establish a viable social policy regime. I criticise this in two directions. First, I take issue with the theory that anti-discrimination law and policy has to be part of social policy. Actually, the field has a mission which differs from social policy, in that it addresses disadvantage resulting from othering, combating stereotypes as well as promoting accomodation of difference. Second, I show how the critique of judicialisation of policy is not unique to anti-discrimination law and policy. The so called turn to rights based employment law has been criticised under this mantra by those who fear that collective labour law mechanisms will become less prevalent. Further, those who have engaged with anti-discrimination law for a much longer time than those criticising it have also devised means to overcome the individualistic tendencies of rights adjudication. They have (partly successfully) argued in favour of establishing equality bodies and creating positive obligations. Thus, the critique neglects the field it takes on, and does not accept the fact that anti-discrimination law and policy must be considered a field in its own right instead of the servant of social law and policy.
Now, this is more a summary than an abstract - since I realise that not everyone reads German.

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Throughout Africa, charismatic Christianity has been caricatured as an inhibitor of democratization. Its adherents are said either to withdraw from the rough and tumble of politics ('pietism') or to preach a prosperity gospel that encourages believers to pour their resources into their churches in the hope that God will 'bless' them. Both courses of action are said to encourage such people to be politically quietist, with no interest in democratization or other forms of political activity. This is said to thwart democratization. This article utilizes an ethnographic case study of a 'progressive' charismatic congregation in Harare, Zimbabwe, in 2007, to provide evidence that 'pietism' and 'prosperity' are not the only options for charismatic Christianity. Drawing on the concept of 'spiritual capital', it argues that some varieties of charismatic Christianity have the resources to contribute to democratization. For example, this congregation's self-styled 'de-institutionalization' process is opening up new avenues for people to learn democratic skills and develop a worldview that is relationship-centred, participatory, and anti-authoritarian. The article concludes that spiritual capital can be a useful tool for analysing the role of religions in democratizations. It notes, however, that analysts should take care to identify and understand what variety of spiritual capital is generated in particular situations, focusing on the worldviews it produces and the consequences of those worldviews for democratization. © 2009 Taylor & Francis.