Polímeros conductores de polifurano : síntesis y caracterización electroquímica, estructura y morfología

El trabajo expuesto en esta memoria ha tenido como objetivo establecer las condiciones de síntesis mas adecuadas para la obtención de películas de polifurano dopadas con perclorato sódico estables, electroactivas y con alto contenido aromático. Con este fin se ha seleccionado la vía electroquímica y mas concretamente la electrogeneración potenciostatica, analizando la influencia de los distintos parámetros químicos y electroquímicos sobre la generación y respuesta electroquímica del material, sobre su estructura y su morfología superficial e interna. Asi mismo, se ha analizado su estabilidad térmica a través de la evolución no solo de su estructura, sino además de su morfología. También se ha examinado el efecto que la temperatura y la humedad ejercen en la conductividad de estos materiales.Depto. de Química FísicaFac. de Ciencias QuímicasTRUEpu

Polímeros conductores de polifurano : síntesis y caracterización electroquímica, estructura y morfología

El trabajo expuesto en esta memoria ha tenido como objetivo establecer las condiciones de síntesis mas adecuadas para la obtención de películas de polifurano dopadas con perclorato sódico estables, electroactivas y con alto contenido aromático. Con este fin se ha seleccionado la vía electroquímica y mas concretamente la electrogeneración potenciostatica, analizando la influencia de los distintos parámetros químicos y electroquímicos sobre la generación y respuesta electroquímica del material, sobre su estructura y su morfología superficial e interna. Asi mismo, se ha analizado su estabilidad térmica a través de la evolución no solo de su estructura, sino además de su morfología. También se ha examinado el efecto que la temperatura y la humedad ejercen en la conductividad de estos materiales

Polipirrol, un buen soporte para electrodos de pilas de combustible de metanol directo (DMFC)

(SPA) El polipirrol es uno de los polímeros conductores más utilizados en la preparación de electrodos debido a su alta actividad catalítica para la oxidación y reducción del metanol. En este trabajo se ha depositado electroquímicamente polipirrol a diferentes potenciales de depósito, Ed, sobre tela de carbón no tejida Freudenberg en medio ácido. Se ha analizado la morfología y la respuesta electroquímica en medio HClO4 y en presencia de HClO4+MeOH antes y después de la síntesis del polipirrol sobre ella. Lastructura de las películas obtenidas se ha estudiado por espectroscopia infrarroja de transformada de Fourier, FTIR. Se observa que el polipirrol mejora las propiedades electroquímicas de la tela de carbón, obteniéndose el mejor resultado para su aplicación como soporte del catalizador en pilas de combustible con la película sintetizada a 1,0V. (ENG) Polypyrrole is one of the most used conducting polymers in electrode building due to its high catalytic activity to the methanol oxidation and reduction. By this motive, polypyrrole has been electrochemically synthesized at constant potential, Ed, on Freudenberg carbon cloth in acid medium. Carbon cloth morphology and electrochemical behaviour in HClO4 and in HClO4+MeOH before and after the polypyrrole eposition have been analysed. The structure of the films was studied by Fourier transform infrared spectroscopy, FTIR. The polypyrrole improves the electrochemical properties of the studied carbon cloth. The biggest charge of the electroactive area is the one synthesized at 1.0V, being the best for its application as catalyst support in fuel cells

Electrochemical study of platinum deposited by electron beam evaporation for application as fuel cell electrodes

Platinum is the most used catalyst in electrodes for fuel cells due to its high catalytic activity. Polymer electrolyte and direct methanol fuel cells usually include Pt as catalyst in their electrodes. In order to diminish the cost of such electrodes, different Pt deposition methods that permit lowering the metal load whilst maintaining their electroactivity, are being investigated. In this work, the behaviour of electron beam Pt (e-beam Pt) deposited electrodes for fuel cells is studied. Three different Pt loadings have been investigated. The electrochemical behaviour by cyclic voltammetry in H2SO4, HClO4 and in HClO4+MeOH before and after the Pt deposition on carbon cloth has been analysed. The Pt improves the electrochemical properties of the carbon support used. The electrochemical performance of e-beam Pt deposited electrodes was finally studied in a single direct methanol fuel cell (DMFC) and the obtained results indicate that this is a promising and adequate method to prepare fuel cell electrodes

Electrochemical study of platinum deposited by electron beam evaporation for application as fuel cell electrodes

Platinum is the most used catalyst in electrodes for fuel cells due to its high catalytic activity. Polymer electrolyte and direct methanol fuel cells usually include Pt as catalyst in their electrodes. In order to diminish the cost of such electrodes, different Pt deposition methods that permit lowering the metal load whilst maintaining their electroactivity, are being investigated. In this work, the behaviour of electron beam Pt (e-beam Pt) deposited electrodes for fuel cells is studied. Three different Pt loadings have been investigated. The electrochemical behaviour by cyclic voltammetry in H2SO4, HClO4 and in HClO4+MeOH before and after the Pt deposition on carbon cloth has been analysed. The Pt improves the electrochemical properties of the carbon support used. The electrochemical performance of e-beam Pt deposited electrodes was finally studied in a single direct methanol fuel cell (DMFC) and the obtained results indicate that this is a promising and adequate method to prepare fuel cell electrodes

Comportamiento electroquímico y en pila de combustible de cátodos fabricados mediante evaporacion electrónica de Pt frente a electrodos comerciales

(SPA) Con el objetivo de disminuir el coste de los electrodos utilizados en las pilas de combustible de membrana polimérica se ha llevado a cabo un estudio de la influencia sobre la respuesta electroquímica y en ensayos en monocelda de pila de combustible de alcohol directo, de la deposición por evaporación electrónica de platino sobre tela de carbón. Se han estudiado en las mismas condiciones dos electrodos comerciales con distinta carga de catalizador y dos electrodos preparados por evaporación electrónica de platino. Se encuentra que la evaporación electrónica de platino sobre tela de carbón ahorra carga de catalizador, aumenta la superficie electroactiva y permite alcanzar rendimientos comparables a los de los electrodos comerciales, mejorando mucho la potencia obtenida por unidad de masa de material catalítico. (ENG) In order to diminish the cost of the electrodes used in polymer membrane fuel cells a study of the influence on the electrochemical response and essays in a single direct methanol fuel cell of the deposition by electronic evaporation of Platinum on carbon cloth has been carried out. Two commercial electrodes with different catalyst loading and two electrodes prepared by electronic evaporation of Platinum have been studied in the same conditions. It can be concluded that electronic evaporation of Platinum on carbon cloth saves catalyst load, increases the electroactive surface area and reaches fuel cell performances comparable with those obtained using commercial electrodes, improving clearly the power obtained per unit mass of catalytic material

Experiencia en la ETS de Ingeniería y Diseño Industrial en la implantación del Doble Grado en Ingeniería en Diseño Industrial y Desarrollo de Producto y en Ingeniería Mecánica por la Universidad Politécnica de Madrid

(SPA) En este trabajo se plantea el desarrollo curricular del Doble Grado en Ingeniería en Diseño Industrial y Desarrollo de Producto y en Ingeniería Mecánica. Se exponen los motivos por los que se decidió implantar, se ofrecen datos de demanda, oferta, notas de corte y se presenta un avance de los resultados académicos del primer curso correspondiente a la primera promoción. (ENG) In this work the study plan of the doble degree in Industrial Desing an Product development and in Mechanical Engineering. The reasons why the double dergree was implanted, the demand, the offer and the students academic results of the first class

New direct alcohol and hydrogen fuel cells for naval and aeronautical applications (PILCONAER)

In the current context of demand for reliable, low cost and low environmental impact energy sources, many countries and companies are mostly focused on fuel cells (FC) in fields as transportation and stationary power generation and portable devices. Lately, FCs have begun to be applied in naval and aeronautical systems due to its high efficiency, low noise and environmental advantages. These applications could range from propulsion systems to auxiliary power units(APU). The main problems associated with the use of FCs in these areas are the current high cost due to the materials used, i.e. Nafion and Pt, the lack of durability testing in these specific conditions, security issues to flammability and high H2 pressures and low availability as a fuel, or the toxicity of methanol used as a fuel, and specific parameters such as weight in aircraft applications and volume in marine applications. Currently it is working on each of these issues, and at this point the ethanol as direct fuel is considered crucial. The use of ethanol as fuel has the advantage of easy transportation, storage and refueling, and is nontoxic. Bioethanol is a promising energy source, produced from raw materials containing sugar or starch. These raw materials exists in all parts of the world and is renewable, which involves the use of local energy sources contributing to the diversification of energy supply, reducing import dependence, increasing security of supply and generating new opportunities for agriculture. The main objective of the project is the development of low power stacks (stacks) fed with methanol (DMFC)and ethanol (DEFC) based on the development of new catalysts and membranes. PILCONAER aims contributing to the development of a sustainable use technology, further commitment to the restoration of the natural environment and biodiversity conservation

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups