Mecanismos fisiológicos de respuesta de la cebada al impacto de la sequía y el elevado CO2 : adaptación al cambio climático

251 p. : il., col.

Impuestos extrafiscales

El presente trabajo es un estudio sobre la extrafiscalidad en los impuestos. En él, se define la extrafiscalidad como tal y se analizan sus características más relevantes. Para ello, en primer lugar se especifica el marco jurídico en el que se regulan los tributos y a continuación se desarrolla su definición y sus particularidades, ofreciendo al lector ejemplos reales donde podemos encontrar impuestos con estas características, como; algunos de los impuestos propios de las Comunidades Autónomas, los nuevos impuestos concertados del País Vasco y por último, el caso del Impuesto sobre las Ventas Minoristas de Determinados Hidrocarburos o también conocido como “céntimo sanitario”, que se incluye en el proyecto por la estrecha relación que guarda con la extrafiscalidad. Al final del trabajo, se encuentran las conclusiones derivadas del análisis de los impuestos extrafiscales.

Ab initio study of anharmonicity in high pressure Cmca-4 metallic hydrogen

Hydrogen is the only atom for which the Schr odinger equation is solvable. Consisting only of a proton and an electron, hydrogen is the lightest element and, nevertheless, is far from being simple. Under ambient conditions, it forms diatomic molecules H2 in gas phase, but di erent temperature and pressures lead to a complex phase diagram, which is not completely known yet. Solid hydrogen was rst documented in 1899 [1] and was found to be isolating. At higher pressures, however, hydrogen can be metallized. In 1935 Wigner and Huntington predicted that the metallization pressure would be 25 GPa [2], where molecules would disociate to form a monoatomic metal, as alkali metals that lie below hydrogen in the periodic table. The prediction of the metallization pressure turned out to be wrong: metallic hydrogen has not been found yet, even under a pressure as high as 320 GPa. Nevertheless, extrapolations based on optical measurements suggest that a metallic phase may be attained at 450 GPa [3]. The interest of material scientist in metallic hydrogen can be attributed, at least to a great extent, to Ashcroft, who in 1968 suggested that such a system could be a hightemperature superconductor [4]. The temperature at which this material would exhibit a transition from a superconducting to a non-superconducting state (Tc) was estimated to be around room temperature. The implications of such a statement are very interesting in the eld of astrophysics: in planets that contain a big quantity of hydrogen and whose temperature is below Tc, superconducting hydrogen may be found, specially at the center, where the gravitational pressure is high. This might be the case of Jupiter, whose proportion of hydrogen is about 90%. There are also speculations suggesting that the high magnetic eld of Jupiter is due to persistent currents related to the superconducting phase [5]. Metallization and superconductivity of hydrogen has puzzled scientists for decades, and the community is trying to answer several questions. For instance, what is the structure of hydrogen at very high pressures? Or a more general one: what is the maximum Tc a phonon-mediated superconductor can have [6]? A great experimental e ort has been carried out pursuing metallic hydrogen and trying to answer the questions above; however, the characterization of solid phases of hydrogen is a hard task. Achieving the high pressures needed to get the sought phases requires advanced technologies. Diamond anvil cells (DAC) are commonly used devices. These devices consist of two diamonds with a tip of small area; for this reason, when a force is applied, the pressure exerted is very big. This pressure is uniaxial, but it can be turned into hydrostatic pressure using transmitting media. Nowadays, this method makes it possible to reach pressures higher than 300 GPa, but even at this pressure hydrogen does not show metallic properties. A recently developed technique that is an improvement of DAC can reach pressures as high as 600 GPa [7], so it is a promising step forward in high pressure physics. Another drawback is that the electronic density of the structures is so low that X-ray di raction patterns have low resolution. For these reasons, ab initio studies are an important source of knowledge in this eld, within their limitations. When treating hydrogen, there are many subtleties in the calculations: as the atoms are so light, the ions forming the crystalline lattice have signi cant displacements even when temperatures are very low, and even at T=0 K, due to Heisenberg's uncertainty principle. Thus, the energy corresponding to this zero-point (ZP) motion is signi cant and has to be included in an accurate determination of the most stable phase. This has been done including ZP vibrational energies within the harmonic approximation for a range of pressures and at T=0 K, giving rise to a series of structures that are stable in their respective pressure ranges [8]. Very recently, a treatment of the phases of hydrogen that includes anharmonicity in ZP energies has suggested that relative stability of the phases may change with respect to the calculations within the harmonic approximation [9]. Many of the proposed structures for solid hydrogen have been investigated. Particularly, the Cmca-4 structure, which was found to be the stable one from 385-490 GPa [8], is metallic. Calculations for this structure, within the harmonic approximation for the ionic motion, predict a Tc up to 242 K at 450 GPa [10]. Nonetheless, due to the big ionic displacements, the harmonic approximation may not su ce to describe correctly the system. The aim of this work is to apply a recently developed method to treat anharmonicity, the stochastic self-consistent harmonic approximation (SSCHA) [11], to Cmca-4 metallic hydrogen. This way, we will be able to study the e ects of anharmonicity in the phonon spectrum and to try to understand the changes it may provoque in the value of Tc. The work is structured as follows. First we present the theoretical basis of the calculations: Density Functional Theory (DFT) for the electronic calculations, phonons in the harmonic approximation and the SSCHA. Then we apply these methods to Cmca-4 hydrogen and we discuss the results obtained. In the last chapter we draw some conclusions and propose possible future work.

Nave-almacén para Riegos del Norte, S. A. en Angucina(La Rioja)

El presente proyecto consiste en el diseño y cálculo de una nave industrial, destinada al desempeño de tareas como centro de almacenaje y distribución de material de riego. El emplazamiento de la mencionada base logística que concierne a este proyecto se ubica en la parcela Nº - 175 del POLÍGONO -7- LA LOMA, situado en el municipio Riojano de Anguciana perteneciente a la comarca de Haro, cercano a las ciudades de Logroño (La Rioja) y Vitoria (País Vasco).

Modelización de procesos hidrológicos y de contaminación por nitratos mediante dos códigos numéricos (SWAT y MOHID). Cuenca agrícola del río Alegría (País Vasco)

245 p.+ anexos

Análisis comparado del impuesto sobre sociedades. Estado español versus País Vasco

Este trabajo analiza las principales diferencias normativas, en materia de impuesto sobre sociedades, entre normativa de Territorio Común y País Vasco.

Un análisis sobre la economía sumergida

Un análisis sobre la economía sumergida. Idioma: español

Ayudas de Estado en el ámbito fiscal

El presente trabajo estudia el régimen de ayudas de Estado desde la perspectiva del área fiscal y en concreto analizando la problématica derivada de dicho régimen y el Concierto Económico y los Derechos Históricos en la CAPV. El trabajo está redactado y será defendido en castellano.

Impuesto sobre el patrimonio: divergencias normativas en la Comunidad Autónoma Vasca

El presente trabajo analiza las principales divergencias que se dan a nivel autonómico en cuanto a la normativa que sanciona el patrimonio neto. Tratando de este modo de esclarecer de un modo técnico cuales son y qué efectos producen dichas diferencias, y si realmente es tanta la diferencia existente, en cuanto a tributación, entre las tres Haciendas Forales. A pesar de que son muchas las diferencias existentes, he considerado que las que mayor diferencia suponen para el contribuyente son las derivadas de la tarifa del impuesto, del mínimo exento, del tratamiento y valoración de las participaciones y del límite conjunto renta patrimonio. De ahí, que una vez realizada una introducción en lo referente a los aspectos más genéricos del impuesto se analizan los aspectos del impuesto que mayor debate generan en el ámbito tributario, y que son los que mayor parte del trabajo soportan. Con los resultados obtenidos del análisis el lector podrá evaluar, de manera objetiva y apoyándose en un trabajo técnico, los diferentes aspectos analizados.

Derecho de la Unión Europea y Concierto Económico: principios vertebradores de la autonomía tributaria foral en el marco de la Unión Europea

2 vols (1130 p.)- Publicación temporalmente embargada