960 resultados para Conversión al islam


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The Er3+-Yb3+ codoped Al2O3 has been prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)(3)]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)(3) center dot 5H(2)O] and ytterbium nitrate [Yb(NO3)(3) center dot 5H(2)O]. The phase structure, including only two crystalline types of doped Al2O3 phases, theta and gamma, was obtained for the 1 mol% Er3+ and 5 mol% Yb3+ codoped Al2O3 at the sintering temperature of 1,273 K. By a 978 nm semiconductor laser diodes excitation, the visible up-conversion emissions centered at about 523, 545, and 660 nm were obtained. The temperature dependence of the green up-conversion emissions was studied over a wide temperature range of 300-825 K, and the reasonable agreement between the calculated temperature by the fluorescence intensity ratio (FIR) theory and the measured temperature proved that Er3+-Yb3+ codoped Al2O3 plays an important role in the application of high temperature sensor.

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Desde su creación en 1976 la Sociedad Española de Antropología Física (SEAF) viene celebrando sus congresos bienales de forma ininterrumpida en distintas ciudades españolas. Estos encuentros, destinados a la discusión de los avances y resultados de las investigaciones bioantropológicas, suponen un foro de debate científico en el que participan investigadores de diversas áreas interesados en los estudios de Antropología Física, promoviendo la interacción entre especialistas e investigadores en formación. Asimismo, y dado el interés que esta disciplina despierta en la sociedad en general, la celebración de los Congresos de la SEAF permite mostrar las novedades acontecidas en el ámbito de la ciencia bioantropológica, facilitando la difusión del conocimiento más allá de la esfera académica. En este marco de reuniones científicas, los profesores del área de Antropología Física de la Facultad de Ciencia y Tecnología de la Universidad del País Vasco-Euskal Herriko Unibertsitatea (UPV/EHU) han sido los encargados de organizar el XVIII Congreso de la SEAF, celebrado en Bilbao durante los días 19 a 21 de junio de 2013. Este libro recoge las ponencias y principales comunicaciones presentadas en el XVIII Congreso, seleccionadas para su publicación y agrupadas en diferentes bloques temáticos que recogen algunas de los conocimientos actuales de la investigación bioantropológica: Ecología Humana, Biología Esquelética y Antropología Forense Paleoantropología y Primatología, y Diversidad Genética Humana. Se ha pretendido mostrar algunas de las cuestiones más relevantes actualmente y la proyección futura de la investigación en Antropología biológica, encaminada tanto al cuestionamiento de paradigmas (como la preponderancia de África en la evolución humana o la existencia de una única especie humana a partir del Pleistoceno Superior, entre otros), como a la comprensión de la relación fenotipo-genotipo, entre otras cuestiones de gran importancia para la reconstrucción de la historia evolutiva de nuestra especie. Sirvan las ponencias invitadas como ejemplo del nuevo enfoque de algunas áreas de la investigación en Antropología.

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[ES] El retablo mayor de la localidad guipuzcoana de Lazkao fue realizado por Juan de Ursularre en 1683, siguiendo los parámetros de la retablística barroca. Queriendo engrandecer su aspecto, fue paulatinamente transformado durante el siglo XVIII. Por ello se concibió un nuevo cascarón con pinturas enviadas desde Madrid y más tarde se adecuó a los nuevos gustos neoclásicos mediante una radical reforma realizada en 1791 que consistió en eliminar todo atisbo de decoración barroca.

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662 p.

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El Juego de la Adaptación al Cambio Climático (ADAPTECC) es un juego de Rol diseñado para que los participantes experimenten las dificultades que surgen, tanto a nivel local como a nivel regional, cuando las autoridades correspondientes tienen que adoptar medidas de adaptación. La adaptación requiere anticipar los efectos adversos del Cambio Climático (CC) y tomar medidas para prevenir y minimizar el daño debido a los impactos del CC. Cada jugador se introduce en el rol de un alcalde o concejal de un municipio afectado por el CC, que debe decidir sobre las estrategias y medidas de adaptación de su municipio, o bien en el rol de un miembro del Departamento de Medio Ambiente de la región que debe repartir el presupuesto para adaptación entre los diferentes municipios. Al finalizar el juego, los participantes tendrán una mejor comprensión de los retos que plantea la adaptación al CC.

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El programa propuesto por el Tribunal del TFG para la mención de Urbanismo, Paisaje y Territorio consiste en la realización de unas piscinas naturales de agua de río con sus edificaciones de apoyo (vestuarios, aseos, sala polivalente, taberna y almacenaje) y un albergue de 10 habitaciones dobles y grupales, en la ladera al suroeste de la villa de Navarrenx, en el espacio exterior a la ciudad entre la fortificación y el rio Gave D’Oloron.

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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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The individuals studied came from commercial catches on the coastal area off Mar del Plata. The monthly distribution of sizes shows that the juvenile stay in coastal waters, while the adult individuals leave those waters during winter season to return there in the spring during the season of sexual maturation and spawning, when the water reaches temperature of 10-11°C. The jack mackerel is a relatively small fish, compared with other species of its genus, and has a total length of scarcely 25 cm. The comparison of indexes and mesurements does not reveal any marked difference between sexes, except for the total length, which is greater in the females. Sexually nature individuals at a lenth of 13 cm have been found. Spawning takes place in coastal waters. A great part of the population spawns from December to January. There are oscillations ranging from November to March. On this latter month mature individuals of smaller size have veen found. The jack mackerel feeds usually on copepods and other planktonic organims, but it can feed also on juveniles of other fishes. This fish is caught throghout the whole year. The catches show their greater peak during winter; one other non-constant peak occurs during the spring (October-November) and declines shoraply during the summer months. It follows from this that the time of greates catch does not coincide with spawning season, or with the appearence of the greatest mean sizes. This happens because the interests of the fishermen are attracted during those months by others species of greater commercial value.

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Under the name of Campañas Oceanográficas Mar del Plata I-V, five oceanographic surveys were done together with the Servicio de Hidrografía Naval, in the area between Faro Querandí and Mar del Sur. (Argentina, Province of Buenos Aires). A total of 82 oceanographic stations were covered and physical-chemical (temperature, oxygen, salinity determinations), sedimental and biological samplings (plankton and bottom organisms) were obtained. Bottom organisms collections were made with a conventional type of dredge 1 meter wide and 46 cm high grame with a net of thin mesh 2,60 m. Macrofauna components were only considered. This data allowed us to attempt a bionomic and litological chart of the studied area.As the sediments seem to have great heterogeneity over the hole studied area, in many cases the bottom fauna collections belonged to defferent associations which made difficult the limitations of areas covered by each one. Anyway we can draw that we are very near the minimun limits.

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En este Trabajo de Fin de Grado desarrollado en la empresa On4U, se ha implementado un módulo para Magento, cuya función principal es la generación dinámica de parrillas de productos en base al análisis del tiempo meteorológico, teniendo en cuenta la localización del cliente. Además, el módulo guarda automáticamente las compras efectuadas, junto con la información externa, para un posible análisis posterior que relacione los hábitos de compra con el tiempo meteorológico. Aunque se haya centrado en este caso de uso, se ha desarrollado con un enfoque modular, de tal manera que fuese fácil de integrar en el módulo el uso de otra fuente abierta de información. Para poder realizar el proyecto, se ha tenido que profundizar en varios conceptos relacionados con la plataforma de eCommerce Magento, entre ellos, el patrón Modelo-Vista-Controlador y el ciclo de vida de una petición.

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Gordon E. Moore, co-fundador de Intel, predijo en una publicación del año 1965 que aproximadamente cada dos años se duplicaría el número de transistores presentes en un circuito integrado, debido a las cada vez mejores tecnologías presentes en el proceso de elaboración. A esta ley se la conoce como Ley de Moore y su cumplimiento se ha podido constatar hasta hoy en día. Gracias a ello, con el paso del tiempo cada vez se presentan en el mercado circuitos integrados más potentes, con mayores prestaciones para realizar tareas cada vez más complejas. Un tipo de circuitos integrados que han podido evolucionar de forma importante por dicho motivo, son los dispositivos de lógica programable, circuitos integrados que permiten implementar sobre ellos las funciones lógicas que desee implementar el usuario. Hasta hace no muchos años, dichos dispositivos eran capaces de implementar circuitos compuestos por unas pocas funciones lógicas, pero gracias al proceso de miniaturización predicho por la Ley de Moore, hoy en día son capaces de implementar circuitos tan complejos como puede ser un microprocesador; dichos dispositivos reciben el nombre de FPGA, siglas de Field Programmable Gate Array. Debido a la mayor capacidad y por lo tanto a diseños más complejos implementados sobre las FPGA, en los últimos años han aparecido herramientas cuyo objetivo es hacer más fácil el proceso de ingeniería dentro de un desarrollo en este tipo de dispositivos, como es la herramienta HDL Coder de la compañía MathWorks, creadores también Matlab y Simulink, unas potentes herramientas usadas ampliamente en diferentes ramas de la ingeniería. El presente proyecto tiene como objetivo evaluar el uso de dicha herramienta para el procesado digital de señales, usando para ello una FPGA Cyclone II de la casa Altera. Para ello, se empezará analizando la herramienta escogida comparándola con herramientas de la misma índole, para a continuación seleccionar una aplicación de procesado digital de señal a implementar. Tras diseñar e implementar la aplicación escogida, se deberá simular en PC para finalmente integrarla en la placa de evaluación seleccionada y comprobar su correcto funcionamiento. Tras analizar los resultados de la aplicación de implementada, concretamente un analizador de la frecuencia fundamental de una señal de audio, se ha comprobado que la herramienta HDL Coder, es adecuada para este tipo de desarrollos, facilitando enormemente los procesos tanto de implementación como de validación gracias al mayor nivel de abstracción que aporta.