3,726 research outputs found
Baryon semileptonic decays: the Mexican contribution
We give a detailed account of the techniques to compute radiative corrections
in baryon semileptonic decays developed over the years by Mexican
collaborations. We explain how the method works by obtaining an expression for
the Dalitz plot of semileptonic decays of polarized baryons including radiative
corrections to order , where is the
four-momentum transfer and is the mass of the decaying baryon. From here
we compute the totally integrated spin angular asymmetry coefficient of the
emitted baryon and compare its value with other results.Comment: 10 pages. Prepared for the Commemorative Volume of the Divison of
Particles and Fields of the Mexican Physical Societ
Preparation and characterisation of new materials for electrolytes used in Direct Methanol Fuel Cells
Summary
The aim of this PhD thesis is the preparation and study of new materials to be used as electrolytes in Direct Methanol Fuel Cells (DMFC) in order to reduce crossover of methanol. Different materials have been prepared, including polymer dispersed liquid crystals, crosslinked polymers with high protonic conductivity and polymeric liquid crystals. Moreover, a methodology to characterise potential new materials for their application in DMFC has been developed. The absorption properties of water and methanol in the materials have been studied in different conditions and compared with the results obtained for commercial Nafion membranes used in DFMC. The absorption and diffusion properties of water and methanol through the materials have been studied by means of Fourier Transform Infrared Spectroscopy and thermal analysis techniques. The methodology provides important information to analyse the interactions between the different functional groups of the polymers and the solvents commonly used in DMFC. Finally, a device has been designed and set-up to analyse the effect on crossover of methanol of the electro-osmotic drag and the polarisation of the polymeric electrolytes.Martinez Felipe, A. (2009). Preparation and characterisation of new materials for electrolytes used in Direct Methanol Fuel Cells [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8327Palanci
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