58 resultados para rendimiento medio
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[ES]Este proyecto tiene como objetivo analizar el rendimiento de diferentes técnicas criptográficas que el protocolo de movilidad HIP puede utilizar para proporcionar los servicios de seguridad que se determinen. Lo primero que se hará será seleccionar los diferentes algoritmos criptográficos que HIP podría utilizar para cubrir los servicios de seguridad considerados más relevantes, estos son autenticación, confidencialidad e integridad de datos. A continuación se identificarán los parámetros más significativos en relación al rendimiento y se definirá un escenario y un plan de pruebas para realizar las mediciones. Posteriormente se realizarán las mediciones con los algoritmos criptográficos previamente seleccionados, y por último se analizarán y valorarán los resultados obtenidos para así determinar la eficiencia de cada algoritmo criptográfico.
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[ES]El objetivo de este proyecto ha sido desarrollar una herramienta software que permita medir el rendimiento de redes con tecnología móvil 4G, también conocida como LTE. Para ello se ha creado un sistema software que está compuesto por una aplicación móvil y un servidor de aplicaciones. El sistema en conjunto realiza la función de recoger indicadores de calidad de la red móvil de diversa índole, que posteriormente son procesados utilizando herramientas software matemáticas, para así obtener gráficas y mapas que permiten analizar la situación y el rendimiento de una red 4G concreta. El desarrollo del software ha llegado a nivel de prototipo y se han realizado pruebas reales con él obteniendo resultados positivos de funcionamiento.
Análisis de rendimiento de aplicaciones ITS con el protocolo de gestión de movilidad de redes NeMHIP
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[ES]Este estudio tiene como objetivo analizar el rendimiento de diferentes aplicaciones ITS sobre el protocolo de movilidad de redes NeMHIP, el cual garantiza un alto nivel de seguridad y de calidad de servicio. En primer lugar, se seleccionarán las diferentes aplicaciones. A continuación, se identificarán los parámetros más significativos para medir el rendimiento y se definirá un plan de pruebas y un escenario. Posteriormente se realizarán las medidas con las aplicaciones previamente seleccionadas, y por último se analizarán los resultados obtenidos para determinar la eficiencia de cada aplicación sobre el protocolo NeMHIP.
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Este Trabajo de Fin de Grado estudia el uso del Producto Interior Bruto (PIB) como medida de bienestar. Al tiempo que se realiza el análisis de la contabilidad nacional y, en mayor profundidad del PIB, se detallan algunas medidas alternativas. Éstas han surgido como consecuencia de la búsqueda de indicadores que incluyan en sus mediciones, no solo el crecimiento económico, sino también otra serie de variables que son relevantes y que el PIB no contempla (como los recursos naturales, la contaminación, la calidad de vida o la igualdad en la distribución de la renta de un país, por ejemplo). Así, surgen nuevos indicadores como el PIB ambientalmente ajustado, el Índice de Mejor Vida, el Índice de Progreso Genuino o la Huella Ecológica, entre otros. Como resultado de este análisis se concluye que la medida que mejor refleja el bienestar depende del objetivo específico que se busque investigar. En otras palabras, hoy en día ninguna medida es capaz de contestar todas las preguntas relacionadas con el bienestar de la población. Sin embargo, el PIB no está configurado –ni fue creado- como una medida de bienestar de un país. Por lo tanto, actualmente es preciso acompañar la información de este indicador con la de otros alternativos de tal manera que podamos tener una imagen más completa sobre el nivel de bienestar de un país.
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[ES]En este proyecto se realizará un análisis del protocolo de nivel de transporte multi-path TCP en una maqueta de pruebas. Para poder llevar a cabo este análisis del protocolo, diseñaremos y construiremos un entorno de pruebas controlado en el que simularemos diferentes problemas y situaciones en la red y analizaremos las respuestas del protocolo ante estos fallos.
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351 p.
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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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58 p.
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170 p.
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250 p. + anexos
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280 p.
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162 p.
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[EN]Due to the limitations associated with fossil fuels it is necessary to promote energy sources that are renewable as well as eco-friendly, such as biogas generated in anaerobic digesters. The biogas, composed principally of methane and CO2, is the result of the biodegradation of organic matter under anaerobic conditions. Its use as fuel is limited by the presence of minority compounds such as hydrogen sulphide (H2S); therefore, its pre-treatment is necessary. Currently there are various technologies for the removal of H2S from a gas stream, but most of them are based on physic-chemical treatments which have a number of drawbacks as reactive consumption, generation of secondary flows, etc. Biofiltration has been used as an efficient and low cost alternative to conventional purification processes, and excellent results for the degradation of H2S have been obtained. However process can be limited due to the progressive ageing of the support material, along with the loss of nutrients and other specific characteristics necessary for the good development of biomass. The purpose of this project is to develop a mixed support consisting of a mixture of an organic material and an inorganic support for its application in the removal of the H2S from biogas. This support material helps to optimize the characteristics of the bed and extend its lifespan. The development of such material will contribute to the implementation of biofiltration for treating biogas from anaerobic digesters for its use as biofuel. The inorganic material used is electric arc furnace (EAF) black slag, a by-product generated in large quantities in the production of steel in the Basque Country. Although traditionally the slag has been used in civil engineering, its physicochemical characteristics make it suitable for reuse as a filter medium in biofiltration. The main conclusion drawn from the experimental results is that EAF black slag is a suitable co-packing material in organic biofilters treating H2S-polluted gaseous streams. High pollutant removal rates have been achieved during the whole experimental period. The removal capacity recorded in biofilters with less inorganic material was higher than in those with higher slag portion. Nevertheless, all the biofilters have shown a satisfactory response even at high inlet loads (48 g·m-3·h-1), where the RE has not decreased over 82%.
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[ES] Durante pruebas cíclicas de larga duración ha sido probada que las estrategias para gestionar la fatiga pueden ser un factor determinante. A pesar de ello, este mismo fenómeno no está del todo probado que pueda darse en esfuerzos máximos de corta duración. Es por eso, que el objetivo de este trabajo ha sido analizar si variando el grado de conocimiento de los atletas durante este tipo de pruebas puede darse alguna alteración en su rendimiento. METODO: Siete deportistas varones completaron durante tres diferentes días un mismo protocolo (8 repeticiones máximas de 30 metros con un minuto de recuperación) en el que se varió la información que se les deba. Así, el primer día se les señaló que realizarían 4 repeticiones, pero cuando finalizaron se les indicó que realizarían 4 más (Prueba decepción). El segundo día, no se les informó del número de repeticiones a realizar (Prueba Suspense) y se les mandó parar al realizar la octava. Y por último, el tercer día se les señaló que realizarían 8 repeticiones (Prueba Control). RESULTADOS: Diferencias significativas (p>0.05) se encontraron en los tiempos de las cuatro primeras repeticiones entre la Prueba Suspense y Prueba Decepción. CONCLUSIÓN: Los resultados muestran como en pruebas máximas de corta duración las estrategias de gestión de la fatiga se pueden dar de manera anticipatoria al número de repeticiones a realizar.
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[ES] El presente trabajo ha estudiado la eficacia de la asignatura de Educación Física dentro del Sistema Educativo Español como método de inclusión para el alumnado con Parálisis Cerebral. Hemos realizado la Fundamentación Teórica sobre la Educación Física y la Parálisis Cerebral y hemos explicado la metodología utilizada hasta ahora en las clases (LOCE 2002 y LOMCE 2014) con el objetivo de lograr la integración de estas personas en las clases de E. Física y en la sociedad. Además, hemos llevado a cabo un caso práctico en el que se asistió a una clase de Educación Física con un paralítico cerebral en el Instituto Valle del Ebro (Tudela, Navarra), con el fin de analizar, tanto la clase impartida por el profesor, como la situación que vivía el alumno dentro de la misma. Los resultados de algunas investigaciones avalan que aún queda mucho camino por recorrer en esta área de intervención, Orta Tierra, J.; Badia Corbella, M.; Mayán, Núñez Mª Teresa entre otros. Por último, hemos propuesto el modelo de intervención metodológica por proyectos (procesos) en la EF de la próxima década, con vistas a su posible utilización con alumnos que presenten este trastorno.