Aplicación del análisis de componentes principales a la inmunización financiera: el caso del mercado español de deuda pública

This work is licensed under a Creative Commons Attribution 3.0 License.

Modelo de canal para caracterizar la señal dispersada por un parque eólico en la banda UHF e influencia sobre la calidad de servicio de DVB-T

288 p. : il.

Dispersión urbana en el Suelo No Urbanizable del País Vasco: la distorsión del planeamiento en la Reserva de la Biosfera de Urdaibai

Creative Commons Reconocimiento-NoComercial 3.0 España

Contextualización y análisis de impacto de medidas de política económica

Duración (en horas): Menos de 10 horas. Destinatario: Estudiante y Docente

La dispersión urbana en el País Vasco. Los patrones de la redistribución espacial de la población y nuevas realidades residenciales y urbanísticas, 1991-2010

La investigación parte de la hipótesis de que la dispersión urbana que ha afectado a las sociedades avanzadas durante las últimas décadas, también ha cobrado fuerza y se ha impuesto en el País Vasco, transformando en pocos años el panorama urbanístico. La población vasca se ha desconcentrado espacialmente y al mismo tiempo la actividad inmobiliaria se ha intensificado y propagado por todo el territorio, afectando tanto a las periferias urbanas como a entornos más excéntricos con escaso dinamismo anterior. De este modo, en un contexto caracterizado por la globalización y los avances tecnológicos, se han generalizado realidades urbanas más dispersas, laxas y discontinuas que han ido desdibujando el anterior modelo urbano de mayor centralidad. Estos procesos territoriales se han afianzado durante las dos últimas décadas en el País Vasco, impulsados por el ciclo económico expansivo. Pero también han estado respaldados por los instrumentos de ordenación territorial, que en su propósito de reequilibrar la red de asentamientos han favorecido la reclasificación de abundante suelo en entornos alternativos a los tradicionales. Como consecuencia, ha tenido lugar un importante desarrollo residencial de asentamientos más periféricos, lo que ha propiciado la dispersión urbana. El emplazamiento y las características de los diferentes ámbitos receptores han canalizado la llegada de distintas clases sociales y se ha traducido en entornos residenciales diferentes. Mientras los espacios aledaños a los grandes centros y ejes urbanos se han desarrollado bajo formas más estandarizadas, en los ámbitos excéntricos pero dotados de amenidades ambientales y residenciales, los nuevos residentes presentan un nivel socioeconómico más elevado y la colonización ha sido más selecta.

Calibración para medidas experimentales

Nivel educativo: Grado. Duración (en horas): Más de 50 horas

Estimación de concentraciones de radicales nitrato (NO . 3) e hidroxilo ( . OH) en la atmósfera a partir de medidas de HCNM de alta resolución temporal

[ES]Los radicales nitrato e hidroxilo son especies químicas implicadas en la contaminación atmosférica. En el presente trabajo se ha tratado de estimar sus concentraciones empleando para ello medidas de las concentraciones de varios compuestos orgánicos volátiles registradas en el Parque Natural de Valderejo (Araba). La metodología de cálculo ya había sido empleada anteriormente para el ·OH y es la primera vez que se ha aplicado a concentraciones de NO·3 en una zona rural. Las concentraciones de radical hidroxilo calculadas (6,02·106 - 8,06·106 molec. cm-3) concuerdan con las obtenidas en medidas y estudios anteriores. En el caso del radical nitrato, las concentraciones estimadas (2,13·1011 – 2,02·1012 molec. cm-3) son bastante superiores a las encontradas en la bibliografía, por lo que se ha concluido que esta técnica de medida no es válida para el cálculo de NO·3 en una atmósfera de fondo rural como Valderejo. Esta desviación se debe probablemente a otros procesos no contemplados en la hipótesis de cálculo, por lo que se propone continuar con el estudio en este área.

Medidas de la calidad de las redes 4G

[ES]Este documento describe un proyecto que comprende un análisis sobre la calidad y rendimiento de las redes 4G en la actualidad. El análisis se realiza atendiendo a diferentes tipos de parámetros, como son indicadores del nivel físico, que son facilitados por la propia red o estaciones base, o medidas de la calidad percibida por el usuario. Para llevar a cabo este estudio se define previamente una serie de procederes para realizar medidas de los parámetros a estudiar en diferentes zonas de Bilbao. Una vez obtenidas las medidas comienza el post-procesado en el que se obtiene los resultados y conclusiones del proyecto.

Factores explicativos del fraude empresarial y medidas adoptadas : caso español

El objetivo de este trabajo es analizar la situación del fraude empresarial y su evolución en España, explicando a su vez las diferentes formas de defraudar más habituales en las entidades. Veremos si el fraude se ha visto condicionado por la crisis financiera actual y qué consecuencias acarrea para las entidades afectadas. Por otro lado, existe la creencia generalizada de que en España se defrauda más que en los países del norte de Europa, por razones sociológicas, culturales y educativas. Pero, ¿es este tópico cierto? ¿cuáles son las variables que determinan la ocurrencia de delitos económicos en las organizaciones? Para lograr soluciones eficaces en la lucha contra el fraude es necesario comprender previamente cuáles son las razones que lo motivan. Por ello, se prestará especial atención a los factores socioculturales que influyen en el comportamiento del defraudador, intentando calibrar la importancia de estas variables. Esto nos permitirá conocer si existe un perfil de defraudador más frecuente, y en caso afirmativo saber cuál es. Una vez analizadas las razones por las que se defrauda, se procederá a estudiar la legislación existente referida a la lucha contra el fraude a nivel nacional, y la normativa europea adoptada en España. Asimismo, se comentarán algunas de las herramientas que las sociedades españolas emplean de forma más habitual para detectar irregularidades y las medidas internas que se toman al respecto. Finalmente, se extraen una serie de conclusiones que nos permitirán avanzar en el conocimiento de la situación del fraude corporativo en España y en su prevención.

Cómo puede influir la política económica en el nivel y el crecimiento del nivel de vida? Algunas medidas para fomentar el crecimiento económico

En este trabajo se ha utilizado el modelo de Solow con el objetivo de estudiar el crecimiento económico. Se define la tasa de ahorro de la regla de oro (aquella que permite un mayor consumo para los individuos) y se calcula el capital, el consumo y la producción en el estado estacionario. Basándonos en el modelo de Solow y mediante un ejercicio, mostramos que cuando la tasa de crecimiento del progreso tecnológico, gA, es positiva y crece de una forma continuada, obtiene aumentos de todas las variables (consumo, producción y capital) también de una forma continuada. Por el contrario, si el estado de la tecnología, A, aumentase solo en un periodo, obtendríamos un valor mayor para cada variable pero este aumento no se mantendría de forma continuada, ya que las tasas de crecimiento volverían a su nivel inicial. Finalmente proponemos diferentes medidas para fomentar el crecimiento económico, entre las que destacan el fomento del progreso tecnológico, gA, y la inversión en capital público y capital humano.

Valoración del estado ecológico de la costa rocosa de Urdaibai (Bizkaia), mediante el estudio de fitobentos intermareal

Dentro de las medidas protectoras sobre la Reserva de la Biosfera de Urdaibai se encuentra el EDAR (Estación Depuradora de Aguas Residuales) de Lamiaran (Bermeo), que entrará en funcionamiento próximamente (otoño 2014). Para evaluar su impacto sobre el medio costero, el presente estudio realiza una primera valoración del estado ecológico de la costa abierta de la reserva mediante diversos parámetros del fitobentos intermareal. Se estableció una red de muestreo compuesta por dos localidades impactadas y cuatro control. En cada localidad se eligieron aleatoriamente dos estaciones y se muestrearon dos niveles en la zona intermareal inferior. Las localidades impactadas por aguas residuales reflejaban valores bajos de riqueza específica, cobertura, diversidad y cobertura de perennes junto a una mayor abundancia de especies estacionales de morfología simple. Sin embargo los análisis estadísticos no detectaron diferencias significativas entre ambos grupos de localidades (impactadas vs control) detectando únicamente diferencias significativas a nivel de estación, debido en gran medida al efecto de la dispersión de las unidades muestrales para los parámetros estudiados.

Advanced Reaction Systems for Hydrogen Production

[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.

Charge and spin transport in graphene devices

170 p.

Measurement of polycyclic aromatic hydrocarbons in ambient air by fluorescence spectroscopic techniques

250 p. + anexos

Medidas radioeléctricas en el interior de edificios.

[ES]En este Trabajo de Fin de Grado se ha realizado una campaña de medidas basada en el cálculo de las pérdidas de propagación en interiores, para la frecuencia de 2 GHz, usada en sistemas móviles. Se han estudiado enlaces de 1 a 80 metros, realizando medidas a lo largo de la planta 4 del edificio B de la Escuela desde diferentes puntos. También se realiza un modelo de propagación completando el trabajo con la medida de las pérdidas de inserción introducidas por materiales y elementos usados en el interior de la Universidad. Para observar adecuadamente el trabajo se realiza una representación gráfica de los resultados obtenidos. Por último utilizando un software se modela el entorno físico de la planta y se comparan los resultados teóricos obtenidos con el caso práctico realizado.