50 resultados para Collectivité viable
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[ES]Este proyecto pretende plantear una solución viable y que, por tanto, resulte económicamente rentable, para la gestión de los lodos de depuradora generados en una estación de tratamiento de aguas residuales. Así, este documento se centrará, por una parte, en realizar un acercamiento al mundo de la depuración de aguas residuales y en estudiar los distintos procesos y tratamientos que se llevan a cabo en una depuradora, y por otra, planteará la valorización energética de los lodos mediante su combustión en una planta de generación de energía eléctrica como la solución al problema de gestión que suponen, no sin antes haber valorado las distintas alternativas posibles en cuanto a la salida que se les podría dar a estos fangos. De esta forma, la base del proyecto, una vez se haya optado por la alternativa de la valorización energética como la opción a desarrollar, consistirá en plantear los principios y fundamentos necesarios para el diseño de la planta de generación de energía eléctrica mediante lodos de depuradora que se pretenderá instalar. Se realizará, por tanto, una descripción de la planta generadora de electricidad detallándose el proceso que se llevará a cabo en la misma. Asimismo, se realizará el dimensionamiento de los diferentes equipos que tomarán parte en dicho proceso. Para finalizar, se planteará el estudio económico y de rentabilidad del proyecto que constituirá la creación de una planta de generación eléctrica mediante lodos, con el fin de comprobar el grado de viabilidad del mismo, y se analizarán los posibles riesgos a los que puede exponerse un proyecto de este tipo.
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[ES]El Trabajo Fin de Grado “Diseño electrónico de una red de comunicaciones para monitorización de estructuras” consiste en el desarrollo de un sistema de comunicación orientado al despliegue y gestión de una red con un alto número de sensores para monitorización de estructuras a bordo de una aeronave. El objetivo principal es hacer viable la utilización de dicha red, partiendo de la premisa de crear una alternativa con mayor eficiencia energética que los sistemas actualmente disponibles para tal fin.
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[es]En sus habitas naturales, los microorganismos están en un estado constante de adaptación a cambios tanto bióticos como abióticos. Ante situaciones de estré s, como por ejemplo cambios en nutriente s, temperatura o de osmolar idad , la s estrategias de supervivencia o adapta ción se puede n manifestar como cambios fenotípicos y genotípicos . En este estudio se analizaron algunos mecanismos de cambio asociados a la supervivencia y la composición proteica de membrana en Escherichia coli (bact eria mesófila), al ser expuesta a condiciones de ayuno y a temperaturas subó ptimas (4 y 20ºC). Al realizar un análisis comparativ o del subproteoma de membrana entre estas dos temperaturas, se observó que ante la ausencia de nutrientes, E. coli respondía de forma diferen te en la expresió n de proteí nas as ociadas a estructura (lipoproteínas), conservación de la energía y transporte, con un aumento en el nú mero de proteí nas expresadas a 20 o C. Se observó, además, una importante diferencia en la supervivencia a estas dos temperaturas, donde el número de células en el estado viable no cultivable (VNC) representaron un porcentaje importante a 20ºC
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[EU]Goierriko eskualdean egun batean burutzen diren bidai guztien %9a bakarrik burutzen da garraio publiko bidez. Hau gertatzearen bizilagunen “aitzakia” nagusia honakoa da: zerbitzua oso txarra da. Niri ordea, ondorengo zalantza datorkit burura: nahiz eta zerbitzua hobea izan, garraio publikoa gehiago erabiliko litzateke? Hau biraka dabilen gurpil zoroa da. Zerbitzua txarra delako ez dabil jende gehiago, baina ez du merezi zerbitzua hobetzea jende gutxi ibiltzen delako. Guzti hau argitzearren eta Goierriko garraio publikoaren hobekuntza sustatzeko zer egin daitekeen aztertzeko garatu da lan hau. Hobekuntza termino hau autobus gehiago jartzearekin erlazionatzen dugu gehienetan, baina nik beste planteamendu bat eman nahi izan diot. Bidaiari gutxi daudenez, ezin dira maiztasun handiz autobusak ezarri, proiektua ez baita bideragarria. Horregatik dagoen zerbitzua, gutxi bada ere, bizilagunei erabat moldatua egotea mahaigaineratu nahi izan dut, bizilagun hauen sentsibilizazioari arreta berezia eskainiz.
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El consumo acelerado de unos recursos energéticos finitos, el impacto ambiental asociado a la producción y uso de las energías tradicionales, la distribución de las reservas de energía , y los precios de las materias primas energéticas , confieren a las fuentes renovables de energía una importancia creciente en la política energética de la mayor í a de los países desarrollados. Además , la valorizació n energética de residuos representa un reto de la sociedad de consumo, por una parte para dar respuest a a los requerimientos de desarrollo sostenible y tamb ié n para fomentar el uso de fuentes de energí a renovables. Entre estos, una de las fuente s más importantes es la biomasa. Es evidente que, un desarrollo de las tecnologías y una planificación adecuada de los aprovechamientos de biomasa, permitiría contrarrestar los efectos perniciosos del excesivo uso de la energía , además de generar empleo, mejoras ambientales y el correspondiente desarrollo rural de zonas degradadas. Las previsiones establec en que antes de 2100 la cuota de participación de la biomasa en la producción mundial de energía debería estar entre el 25 y el 46 %. La producción de hidró geno a partir de biomasa es un proceso interesante y viable, teniendo en cuenta el aumento significa tivo del actual consumo de hidró geno. La producción actual se obtiene mayoritariamente a partir de fuentes fósiles , que emiten grandes cantidades de CO 2 y por lo tanto, surge la necesidad de reducir estas emisiones utilizando materias primas renovables. Por ello, en este sentido, el objetivo principal de este Proyecto Fin de Grado es avanzar en el aprovechamiento de la biomasa vegetal a través de la piró lisis flash y posterior reformado con vapor en línea para la obtención de hidró geno. Para ello, se ha p ropuesto una primera e tapa de piró lisis rápida a 500 º C en un reactor spouted bed cónico y una segunda etapa catal í tica de r eformado con vapor en lí nea en un lecho fluidizado, con el fin de optimizar la temperatura y el tiempo espacial de la segunda etapa
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El proyecto se centra en abastecer la demanda eléctrica del Centro Canino Berquier (Añorbe – Zona Media de Navarra), que cuenta una residencia canina, una consulta veterinaria y una vivienda, mediante un sistema aislado de la red y el uso de energías renovables. El abastecimiento de energía eléctrica mediante energías renovables, contará con un sistema de generación, almacenamiento y distribución, para garantizar un suministro en cantidad y calidad suficiente, del Centro Canino Berquier, Entre las opciones de abastecimiento doméstico renovable, tras un análisis preliminar de los recursos existentes en el emplazamiento del Centro Canino Berquier, se opta por una instalación híbrida eólica fotovoltaica autónoma, respaldada por un grupo electrógeno. Para el correcto dimensionado del mismo, se han seguido los siguientes pasos: - Estimación de los consumos del Centro Canino Berquier. - Caracterización del potencial eólico, evaluación y selección de la turbina eólica. - Radiación solar disponible, dimensionado, inclinación y orientación del generador FV. - Determinación de la capacidad de las baterías y del resto de componentes del sistema. - Cálculo del cableado y elementos de protección. - Esquema de conexiones. Si bien el proyecto, aparentemente, no aporta valor añadido en cuanto a la solución adoptada, (se ha empleado una tecnología técnicamente evaluada y económicamente viable), resulta recomendable como guía a la hora de afrontar proyectos de abastecimiento similares al nuestro.
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Spintronics, or spin electronics, is aimed at efficient control and manipulation of spin degrees of freedom in electron systems. To comply with demands of nowaday spintronics, the studies of electron systems hosting giant spin-orbit-split electron states have become one of the most important problems providing us with a basis for desirable spintronics devices. In construction of such devices, it is also tempting to involve graphene, which has attracted great attention because of its unique and remarkable electronic properties and was recognized as a viable replacement for silicon in electronics. In this case, a challenging goal is to lift spin degeneracy of graphene Dirac states. Here, we propose a novel pathway to achieve this goal by means of coupling of graphene and polar-substrate surface states with giant Rashba-type spin-splitting. We theoretically demonstrate it by constructing the graphene@BiTeCl system, which appears to possess spin-helical graphene Dirac states caused by the strong interaction of Dirac and Rashba electrons. We anticipate that our findings will stimulate rapid growth in theoretical and experimental investigations of graphene Dirac states with real spin-momentum locking, which can revolutionize the graphene spintronics and become a reliable base for prospective spintronics applications.
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[EN] This PhD work started in March 2010 with the support of the University of the Basque Country (UPV/EHU) under the program named “Formación de Personal Investigador” at the Chemical and Environmental Engineering Department in the Faculty of Engineering of Bilbao. The major part of the Thesis work was carried out in the mentioned department, as a member of the Sustainable Process Engineering (SuPrEn) research group. In addition, this PhD Thesis includes the research work developed during a period of 6 months at the Institut für Mikrotechnik Mainz GmbH, IMM, in Germany. During the four years of the Thesis, conventional and microreactor systems were tested for several feedstocks renewable and non-renewable, gases and liquids through several reforming processes in order to produce hydrogen. For this purpose, new catalytic formulations which showed high activity, selectivity and stability were design. As a consequence, the PhD work performed allowed the publication of seven scientific articles in peer-reviewed journals. This PhD Thesis is divided into the following six chapters described below. The opportunity of this work is established on the basis of the transition period needed for moving from a petroleum based energy system to a renewable based new one. Consequently, the present global energy scenario was detailed in Chapter 1, and the role of hydrogen as a real alternative in the future energy system was justified based on several outlooks. Therefore, renewable and non-renewable hydrogen production routes were presented, explaining the corresponding benefits and drawbacks. Then, the raw materials used in this Thesis work were described and the most important issues regarding the processes and the characteristics of the catalytic formulations were explained. The introduction chapter finishes by introducing the concepts of decentralized production and process intensification with the use of microreactors. In addition, a small description of these innovative reaction systems and the benefits that entailed their use were also mentioned. In Chapter 2 the main objectives of this Thesis work are summarized. The development of advanced reaction systems for hydrogen rich mixtures production is the main objective. In addition, the use and comparison between two different reaction systems, (fixed bed reactor (FBR) and microreactor), the processing of renewable raw materials, the development of new, active, selective and stable catalytic formulations, and the optimization of the operating conditions were also established as additional partial objectives. Methane and natural gas (NG) steam reforming experimental results obtained when operated with microreactor and FBR systems are presented in Chapter 3. For these experiments nickel-based (Ni/Al2O3 and Ni/MgO) and noble metal-based (Pd/Al2O3 and Pt/Al2O3) catalysts were prepared by wet impregnation and their catalytic activity was measured at several temperatures, from 973 to 1073 K, different S/C ratios, from 1.0 to 2.0, and atmospheric pressure. The Weight Hourly Space Velocity (WHSV) was maintained constant in order to compare the catalytic activity in both reaction systems. The results obtained showed a better performance of the catalysts operating in microreactors. The Ni/MgO catalyst reached the highest hydrogen production yield at 1073 K and steam-to-carbon ratio (S/C) of 1.5 under Steam methane Reforming (SMR) conditions. In addition, this catalyst also showed good activity and stability under NG reforming at S/C=1.0 and 2.0. The Ni/Al2O3 catalyst also showed high activity and good stability and it was the catalyst reaching the highest methane conversion (72.9 %) and H2out/CH4in ratio (2.4) under SMR conditions at 1073 K and S/C=1.0. However, this catalyst suffered from deactivation when it was tested under NG reforming conditions. Regarding the activity measurements carried out with the noble metal-based catalysts in the microreactor systems, they suffered a very quick deactivation, probably because of the effects attributed to carbon deposition, which was detected by Scanning Electron Microscope (SEM). When the FBR was used no catalytic activity was measured with the catalysts under investigation, probably because they were operated at the same WHSV than the microreactors and these WHSVs were too high for FBR system. In Chapter 4 biogas reforming processes were studied. This chapter starts with an introduction explaining the properties of the biogas and the main production routes. Then, the experimental procedure carried out is detailed giving concrete information about the experimental set-up, defining the parameters measured, specifying the characteristics of the reactors used and describing the characterization techniques utilized. Each following section describes the results obtained from activity testing with the different catalysts prepared, which is subsequently summarized: Section 4.3: Biogas reforming processes using γ-Al2O3 based catalysts The activity results obtained by several Ni-based catalysts and a bimetallic Rh-Ni catalyst supported on magnesia or alumina modified with oxides like CeO2 and ZrO2 are presented in this section. In addition, an alumina-based commercial catalyst was tested in order to compare the activity results measured. Four different biogas reforming processes were studied using a FBR: dry reforming (DR), biogas steam reforming (BSR), biogas oxidative reforming (BOR) and tri-reforming (TR). For the BSR process different steam to carbon ratios (S/C) from 1.0 to 3.0, were tested. In the case of BOR process the oxygen-to-methane (O2/CH4) ratio was varied from 0.125 to 0.50. Finally, for TR processes different S/C ratios from 1.0 to 3.0, and O2/CH4 ratios of 0.25 and 0.50 were studied. Then, the catalysts which achieved high activity and stability were impregnated in a microreactor to explore the viability of process intensification. The operation with microreactors was carried out under the best experimental conditions measured in the FBR. In addition, the physicochemical characterization of the fresh and spent catalysts was carried out by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), N2 physisorption, H2 chemisorption, Temperature Programmed Reduction (TPR), SEM, X-ray Photoelectron Spectroscopy (XPS) and X-ray powder Diffraction (XRD). Operating with the FBR, conversions close to the ones predicted by thermodynamic calculations were obtained by most of the catalysts tested. The Rh-Ni/Ce-Al2O3 catalyst obtained the highest hydrogen production yield in DR. In BSR process, the Ni/Ce-Al2O3 catalyst achieved the best activity results operating at S/C=1.0. In the case of BOR process, the Ni/Ce-Zr-Al2O3 catalyst showed the highest reactants conversion values operating at O2/CH4=0.25. Finally, in the TR process the Rh-Ni/Ce-Al2O3 catalyst obtained the best results operating at S/C=1.0 and O2/CH4=0.25. Therefore, these three catalysts were selected to be coated onto microchannels in order to test its performance under BOR and TR processes conditions. Although the operation using microreactors was carried out under considerably higher WHSV, similar conversions and yields as the ones measured in FBR were measured. Furthermore, attending to other measurements like Turnover Frequency (TOF) and Hydrogen Productivity (PROD), the values calculated for the catalysts tested in microreactors were one order of magnitude higher. Thus, due to the low dispersion degree measured by H2-chemisorption, the Ni/Ce-Al2O3 catalyst reached the highest TOF and PROD values. Section 4.4: Biogas reforming processes using Zeolites L based catalysts In this section three type of L zeolites, with different morphology and size, were synthesized and used as catalyst support. Then, for each type of L zeolite three nickel monometallic and their homologous Rh-Ni bimetallic catalysts were prepared by the wetness impregnation method. These catalysts were tested using the FBR under DR process and different conditions of BSR (S/C ratio of 1.0 and 2.0), BOR (O2/CH4 ratio of 0.25 and 0.50) and TR processes (at S/C=1.0 and O2/CH4=0.25). The characterization of these catalysts was also carried out by using the same techniques mentioned in the previous section. Very high methane and carbon dioxide conversion values were measured for almost all the catalysts under investigation. The experimental results evidenced the better catalytic behavior of the bimetallic catalysts as compared to the monometallic ones. Comparing the catalysts behavior with regards to their morphology, for the BSR process the Disc catalysts were the most active ones at the lowest S/C ratio tested. On the contrary, the Cylindrical (30–60 nm) catalysts were more active under BOR conditions at O2/CH4=0.25 and TR processes. By the contrary, the Cylindrical (1–3 µm) catalysts showed the worst activity results for both processes. Section 4.5: Biogas reforming processes using Na+ and Cs+ doped Zeolites LTL based catalysts A method for the synthesis of Linde Type L (LTL) zeolite under microwave-assisted hydrothermal conditions and its behavior as a support for heterogeneously catalyzed hydrogen production is described in this section. Then, rhodium and nickel-based bimetallic catalysts were prepared in order to be tested by DR process and BOR process at O2/CH4=0.25. Moreover, the characterization of the catalysts under investigation was also carried out. Higher activities were achieved by the catalysts prepared from the non-doped zeolites, Rh-Ni/D and Rh-Ni/N, as compared to the ones supported on Na+ and Cs+ exchanged supports. However, the differences between them were not very significant. In addition, the Na+ and Cs+ incorporation affected mainly to the Disc catalysts. Comparing the results obtained by these catalysts with the ones studied in the section 4.4, in general worst results were achieved under DR conditions and almost the same results when operated under BOR conditions. In Chapter 5 the ethylene glycol (EG) as feed for syngas production by steam reforming (SR) and oxidative steam reforming (OSR) was studied by using microchannel reactors. The product composition was determined at a S/C of 4.0, reaction temperatures between 625°C and 725°C, atmospheric pressure and Volume Hourly Space Velocities (VHSV) between 100 and 300 NL/(gcath). This work was divided in two sections. The first one corresponds to the introduction of the main and most promising EG production routes. Then, the new experimental procedure is detailed and the information about the experimental set-up and the measured parameters is described. The characterization was carried out using the same techniques as for the previous chapter. Then, the next sections correspond to the catalytic activity and catalysts characterization results. Section 5.3: xRh-cm and xRh-np catalysts for ethylene glycol reforming Initially, catalysts with different rhodium loading, from 1.0 to 5.0 wt. %, and supported on α-Al2O3 were prepared by two different preparation methods (conventional impregnation and separate nanoparticle synthesis). Then, the catalysts were compared regarding their measured activity and selectivity, as well as the characterization results obtained before and after the activity tests carried out. The samples prepared by a conventional impregnation method showed generally higher activity compared to catalysts prepared from Rh nanoparticles. By-product formation of species such as acetaldehyde, ethane and ethylene was detected, regardless if oxygen was added to the feed or not. Among the catalysts tested, the 2.5Rh-cm catalyst was considered the best one. Section 5.4: 2.5Rh-cm catalyst support modification with CeO2 and La2O3 In this part of the Chapter 5, the catalyst showing the best performance in the previous section, the 2.5Rh-Al2O3 catalyst, was selected in order to be improved. Therefore, new Rh based catalysts were designed using α-Al2O3 and being modified this support with different contents of CeO2 or La2O3 oxides. All the catalysts containing additives showed complete conversion and selectivities close to the equilibrium in both SR and OSR processes. In addition, for these catalysts the concentrations measured for the C2H4, CH4, CH3CHO and C2H6 by-products were very low. Finally, the 2.5Rh-20Ce catalyst was selected according to its catalytic activity and characterization results in order to run a stability test, which lasted more than 115 hours under stable operation. The last chapter, Chapter 6, summarizes the main conclusions achieved throughout this Thesis work. Although very high reactant conversions and rich hydrogen mixtures were obtained using a fixed bed reaction system, the use of microreactors improves the key issues, heat and mass transfer limitations, through which the reforming reactions are intensified. Therefore, they seem to be a very interesting and promising alternative for process intensification and decentralized production for remote application.
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En este Proyecto de Fin de Grado se ha realizado el diseño y la implementación de la aplicación Baldugenda. El objetivo que tiene Baldugenda es juntar la agenda universitaria física con los teléfonos móviles y los servicios de Google, para que los alumnos puedan llevar al día los exámenes y sus notas mediante la aplicación. El desarrollo se ha realizado en un marco de integración y colaboración directa de los usuarios en el proyecto, partiendo de un producto mínimo viable inicial e integrando el feedback en la progresiva ampliación de las características del servicio.El sistema se basa en una aplicación nativa para Android conectada con los servicios web de Google Calendar y Google Drive. En implementación se han utilizado tecnologías emergentes, todas de código abierto: Sqlite para el almacenamiento de datos, y como cliente una aplicación Android nativa.