69 resultados para Bondi, Clemente.

em Universidad Politécnica de Madrid


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El objeto de este proyecto es definir las obras e instalaciones necesarias para depurar las aguas residuales de la localidad de San Clemente (Cuenca) hasta los límites de la Legislación vigente, y su posterior vertido al cauce del río Rus.

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Próximo a cumplirse el primer aniversario del fallecimiento de Clemente Saénz Ridruejo, el pasado 14 de febrero de 2007 se celebró en la sede de la Real Academia de Bellas Artes un emotivo homenaje a quien había sido maestro de ingenieros a lo largo de una vida en la que la práctica profesional, intensamente ejercida había sido complementada con singular brillantez por otras actividades que hicieron de Clemente un personaje excepcional.

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An intermediate-bandphotovoltaicmaterial, which has an isolated metallic band located between the top of the valence band and bottom of the conduction band of some semiconductors, has been proposed as third generation solar cell to be used in photovoltaic applications. Density functional theory calculations of Zn in CuGaS2:Ti have previously shown that, the intermediate-band position can be modulated in proportion of Zn insertion in such a way that increasing Zn concentration can lead to aband-gap reduction, and an adjustment of the intermediate-band position. This could be interesting in the formation of an intermediate-bandmaterial, that has the maximum efficiency theoretically predicted for the intermediate-band solar cell. In this work, the energetics of several reaction schemes that could lead to the decomposition of the modulated intermediate-bandphotovoltaicmaterial, CuGaS2:Ti:Zn, is studied in order to assess the thermodynamic stability of this material. Calculations of the total free energy and disorder entropy have been taken into account, to get the reaction energy and free energy of the compound decomposition, which is found to be thermodynamically favorable

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El dióxido de carbono (CO2 ) es un gas de efecto invernadero que se encuentra naturalmente en la atmósfera. Las actividades antropogénicas, especialmente las derivadas de la generación eléctrica a partir de combustibles fósiles, están causando que la concentración de este gas aumente significativamente en la atmósfera. Esta situación contribuye al conocido y mundialmente aceptado cambio climático. Dentro de las posibilidades que se barajan para reducir las emisiones a la atmósfera de gases de efecto invernadero destaca el desarrollo de las tecnologías de captura y almacenamiento de CO2 (CAC), las cuales son aplicables principalmente a los grandes focos industriales, como las centrales térmicas, cementeras, refinerías, acerías, industrias cerámicas, etc. Estas tecnologías consisten en la separación del CO2 emitido por dichos focos emisores, para posteriormente comprimirlo y obtener así una corriente concentrada de CO2 , la cual sería susceptible de transportarse e inyectarse en un almacén geológico a una profundidad superior a 800 m para que alcanzara el estado supercrítico. Por lo tanto, el almacenamiento geológico profundo (AGP) de CO2 representa la última etapa de las tecnologías CAC. Aunque se tiene bastante experiencia en el campo de la inyección de CO2 como método para recuperar los yacimientos de petróleo y/o gas, ya agotados o en vías de agotamiento, el concepto de almacenamiento geológico de CO2 , como método de evitar las emisiones de este gas a la atmósfera y mitigar así el efecto invernadero, es relativamente reciente.

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Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store the CO2 in deep saline aquifers at more than 800 m depth, because it achieves its supercritical state. Among the most important aspects concerning the performance assessment of a deep CO2 geological repository is the evaluation of the CO2 leakage rate from the chosen storage geological formation. Therefore, it is absolutely necessary to increase the knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths for CO2 and the physico-mechanical resistance of the sealing formation. Furthermore, the quantification of the CO2 leakage rate is essential to evaluate its effects on the environment. One way to achieve this objective is to study of CO2 leakage on natural analogue systems, because they can provide useful information about the natural performance of the CO2, which can be applied to an artificial CO2 geological storage. This work is focused on the retention capacity of the cap-rock by measuring the diffuse soil CO2 flux in a site selected based on: i) the presence of a natural and deep CO2 accumulation; ii) its structural geological characteristics; and iii) the nature of the cap-rocks. This site is located in the so-called Mazarrón-Gañuelas Tertiary Basin, in the Guadalentin Valley, province of Murcia (Spain) Therefore the main objective of this investigation has been to detect the possible leakages of CO2 from a deep saline aquifer to the surface in order to understand the capability of this area as a natural analogue for Carbon Capture and Sequestration (CCS). The results obtained allow to conclude that the geological sealing formation of the basin seems to be appropriate to avoid CO2 leakages from the storage formation.

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Coal is the most plentiful and evenly distributed fossil fuel worldwide. Based on current production, it is estimated that the reserves will last approximately 130 years. Its use worldwide has been increasing, mainly due to consumption by emerging countries. CO2 emissions generated by combustion and the repercussions of such on climate change support the view that it could no longer be used. CO2 capture may be the solution to continue using it, which would cater for the growing energy demand worldwide. The aim of this study is to compare different processes concerning CO2 capture that may be economically viable, ultimately showing that coal, a fossil energy source widely distributed around the world, can, as a result of using different CO2 capture processes, be used as a clean source of electricity. Hence, in places where geological hurdles may render the costs of CO2 storage considerably higher, since it might have to travel far, coal may be used for other purposes, thus valorising CO2 within the industrial sector. This research is focused on the technical and economic comparison of the most relevant CO2 capture projects designed in Spain using different existing technologies. The oxyfuel project in Ciuden (Leon, Spain), the IGCC Elcogas, precombustion CO2-capture project (Puertollano, Spain) and the postcombustion project in Carboneras (Almeria, Spain) will be analyzed in order to assess the options available to valorise captured CO2. Valorising captured CO2 may be an adequate solution in areas where, although CO2 capture is still possible, storage is not equally so, thus generating a further benefit. The possible uses of CO2 will be assessed in vegetable growing greenhouses, harnessing CO2 in vegetable life cycles. This will also be used in growing algae for subsequent biodiesel production. Both CO2 capture and valorising will eventually lead to the clean use of coal, which will thus enhance the level of self-supply, aiding the development of electric vehicles, which require large amounts of electricity, as well as improve the level of energy autonomy in countries around the world. Another type of fuel, biodiesel, will also be obtained, without this affecting international food prices.

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The progressive depletion of fossil fuels and their high contribution to the energy supply in this modern society forces that will be soon replaced by renewable fuels. But the dispersion and alternation of renewable energy production also undertake to reduce their costs to use as energy storage and hydrogen carrier. It is necessary to develop technologies for hydrogen production from all renewable energy storage technologies and the development of energy production from hydrogen fuel cells and cogeneration and tri generation systems. In order to propel this technological development discussed where the hydrogen plays a key role as energy storage and renewable energy, the National Centre of Hydrogen and Fuel Cell Technology Experimentation in Spain equipped with installations that enable scientific and technological design, develop, verify, certify, approve, test, measure and, more importantly, the facility ensures continuous operation for 24 hours a day, 365 days year. At the same time, the system is scalable so as to allow continuous adaptation of new technologies are developed and incorporated into the assembly to verify integration at the same time it checks the validity of their development. The transformation sector can be said to be the heart of the system, because without neglecting the other sectors, this should prove the validity of hydrogen as a carrier - energy storage are important efforts that have to do to demonstrate the suitability of fuel cells or internal combustion systems to realize the energy stored in hydrogen at prices competitive with conventional systems. The multiple roles to meet the fuel cells under different conditions of operation require to cover their operating conditions, many different sizes and applications. The fourth area focuses on integration is an essential complement within the installation. We must integrate not only the electricity produced, but also hydrogen is used and the heat generated in the process of using hydrogen energy. The energy management in its three forms: hydrogen chemical, electrical and thermal integration requires complicated and require a logic and artificial intelligence extremes to ensure maximum energy efficiency at the same time optimum utilization is achieved. Verification of the development and approval in the entire production system and, ultimately, as a demonstrator set to facilitate the simultaneous evolution of production technology, storage and distribution of hydrogen fuel cells has been assessed.

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Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store CO2 in deep saline aquifers at more than 800m depth, because it reaches its supercritical state. Study of the CO2 natural accumulations as natural analogues of an artificial CO2 storage is very useful in order to understand the CO2 long term behaviour and thus to predict its possible impact on the surficial environment and life. Therefore the main objective of this work is to detect the affection of the CO2 leakages from a deep saline aquifer on the shallow aquifers, all of them located in the Gañuelas-Mazarrón Tertiary basin (Province of Murcia, Spain). This CO2 storage and leakage natural system can be analogous to an artificial CO2 storage with leakage phenomena. In order to reach these objectives, groundwaters from different aquifers in the site have been sampled and analysed for major elements, free and dissolved gases and stable isotopes, particularly ∂ 13 C and 3 He/ 4 He. The results obtained allow to conclude that this natural system is an interesting example of natural analogue for an artificial CO2 storage affected by leakage processes because the shallow fresh aquifers in the site are polluted by CO2 from the deep saline aquifer as a consequence of an intensive over-exploitation of these freshwater aquifers

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The intermediate band (IB) solar cell (Fig. 1) has been proposed [1] to increase photovoltaic efficiency by a factor above 1.5, based on the absorption of two sub-bandgap photons to promote an electron across the bandgap. To realize this principle, that can be applied also to obtain efficient photocatalysis with sunlight, we proposed in recent years several materials where a metal or heavy element, substituting for an electropositive atom in a known semiconductor that has an appropriate band gap width (around 2 eV), forms inside the gap the partially filled levels needed for this aim

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Relatively high amounts of fats or oils (mayor que 40-50 g/kg diet) are frequently used in animal nutrition. Vegetables oils are richer in polyunsaturated fatty acids than animal fats. Most of the works studying the effect of different dietary fat sources are focused either on the existing differences on fat digestibility depending on their fatty acid composition (Wiseman et al., 1991) or on their effect on the carcass fat fatty acid profile (Sanz et al., 1999a). lnformation regarding the effect of dietary fat saturation on fat utilization and deposition it is more limited. lt is generally assumed that, apart from differences in digestion, fatty acids of different composition are equally used for metabolic purposes.

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El Parque Regional del Sureste (declarado mediante la Ley 6/1994, el 28 de junio) representa uno de los espacios de mayor interés y singularidad ambiental de la Comunidad de Madrid y, a la vez, una zona sujeta a grandes presiones derivadas del aprovechamiento minero de sus recursos, intensificado desde los años 70. La reciente aprobación del Plan Rector de Uso y Gestión del Parque (P.R.U.G., Decreto 9/2009, de 5 de febrero) recoge y consolida legalmente la gestión encaminada a salvaguardar y mejorar sus valores ambientales. Respecto a la actividad minera, el aspecto fundamental del P.R.U.G. es que ordena y hace compatible el aprovechamiento de recursos mineros mediante una zonificación y limitación superficial de explotación, para lo que contempla de forma específica el caso de las explotaciones no activas. El estudio llevado a cabo analizó la situación administrativa y progreso de la restauración de las explotaciones inactivas del Parque, interpretadas a la luz de las acciones impuestas por el P.R.U.G. El establecimiento de unas prioridades de actuación que subsanasen situaciones incompatibles con lo establecido supuso la base para formular unas recomendaciones de restauración y uso, a partir del examen del contexto territorial y potencialidades ecológicas de las explotaciones, que respondieran al objetivo de ordenación y mejora de recursos ambientales y sociales del Parque.

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Nowadays, efficiency improvement of solar cells is one of the most important issues in photovoltaic systems and CdTe is one of the most promising thin film photovoltaic materials we can found. CdTe reported efficiencies in solar energy conversion have been as good as that found in polycrystalline Si thin film cell [1], besides CdTe can be easily produced at industrial scale.

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The aim of this work is the theoretical study of the band alignment between the two components of a hybrid organic-inorganic solar-cell. The working organic molecules are metal tetra-sulphonated phthalocyanines (M-Pc) and the inorganic material is nano-porous ZnO growth in the 001 direction. The theoretical calculations are being made using the density functional theory (DFT) using a GGA functional with the SIESTA code, which projects electron wave functions and density onto a real space grid and uses as basis set a linear combination of numerical, finite-range localized atomic orbitals. We also used the DFT+U method included in the code that allows a semi-empirical inclusion of electronic correlations in the description of electronic spectra for systems such as zinc oxide.

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In the present uncertain global context of reaching an equal social stability and steady thriving economy, power demand expected to grow and global electricity generation could nearly double from 2005 to 2030. Fossil fuels will remain a significant contribution on this energy mix up to 2050, with an expected part of around 70% of global and ca. 60% of European electricity generation. Coal will remain a key player. Hence, a direct effect on the considered CO2 emissions business-as-usual scenario is expected, forecasting three times the present CO2 concentration values up to 1,200ppm by the end of this century. Kyoto protocol was the first approach to take global responsibility onto CO2 emissions monitoring and cap targets by 2012 with reference to 1990. Some of principal CO2emitters did not ratify the reduction targets. Although USA and China spur are taking its own actions and parallel reduction measures. More efficient combustion processes comprising less fuel consuming, a significant contribution from the electricity generation sector to a CO2 dwindling concentration levels, might not be sufficient. Carbon Capture and Storage (CCS) technologies have started to gain more importance from the beginning of the decade, with research and funds coming out to drive its come in useful. After first researching projects and initial scale testing, three principal capture processes came out available today with first figures showing up to 90% CO2 removal by its standard applications in coal fired power stations. Regarding last part of CO2 reduction chain, two options could be considered worthy, reusing (EOR & EGR) and storage. The study evaluates the state of the CO2 capture technology development, availability and investment cost of the different technologies, with few operation cost analysis possible at the time. Main findings and the abatement potential for coal applications are presented. DOE, NETL, MIT, European universities and research institutions, key technology enterprises and utilities, and key technology suppliers are the main sources of this study. A vision of the technology deployment is presented.

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En el presente trabajo se ha analizado la diversidad existente en el ADN cloroplástico (ADNcp) de 16 poblaciones distribuidas a lo largo del Sistema Central. Para ello, se ha empleado la técnica de PCR-RFLP (amplificación de fragmentos específicos y posterior digestión con enzimas de restricción) sobre 38 regiones del ADNcp (Grivet et al., 2001).