953 resultados para Rodríguez Adrados, Francisco


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La modelización tridimensional se ha ido implementando como una de las mejores formas de documentación del patrimonio histórico. En concreto, en lo que se refiere a la documentación de petroglifos resulta especialmente interesante en su estudio y difusión. Actualmente, existen diversos métodos de obtener estos modelos 3D, que implican diferentes tipos de instrumental, como escáneres láser o cámaras fotográficas, material informático y software. En este Trabajo Fin de Máster se pretende obtener una visión general de estos métodos,así como proponer una metodología basada en la fotogrametría de objeto cercano, para las necesidades de un proyecto concreto: el proyecto Tamanart en Marruecos. Para ello se realizan dos pruebas; una de laboratorio y otra en el Museo Arqueológico Nacional, para comprobar la viabilidad de esta metodología y sus futuras aplicaciones. ABSTRACT: 3D modeling has been implemented in the last years as one of the best ways to document historical and cultural heritage. In particular, referring to petroglyph documentation it is specially interesting to its study and dissemination. Nowadays, there are several methods to obtain this 3D models that implies different kinds of instruments, like laser-scanners or photographic cameras and computer hardware and software. In the present Master’s Dissertation it is intended to obtain a general vision of this methods,as well as propose a methodology using closed range photogrammetry, based in the needs of a specific project: Tamanart Project, in Morocco. For this purpose two tests are made, one of them in laboratory and the other in the Museo Arqueológico Nacional, to check the feasibility of this methodology and their future applications.

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Texto fechado en Cádiz, fecha del front. 1735

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Diseño y simulación del comportamiento acústico del recinto bajo estudio con el sistema refuerzo sonoro instalado. El objeto de este proyecto fin de carrera es el de diseñar y simular el comportamiento acústico de un pabellón polideportivo con la instalación de un sistema de refuerzo sonoro adecuado a sus características arquitectónicas (y a los eventos a realizar). En estas simulaciones se utilizarán varias herramientas de diseño para poder comparar resultados y así obtener una mejor sonorización del recinto. Se llevarán a cabo varios diseños de sistemas de refuerzo sonoro para este recinto deportivo con el conocido programa de simulación sonora EASE, que incorpora sistemas de varias vías, filtros, etc. Otro software de simulación sonora a usar será EASE Focus, más intuitivo y principalmente enfocado a fuentes sonoras del tipo "arrays lineales", en dos dimensiones. En cuanto al método y las fases de trabajo, inicialmente, será necesario obtener información del estado actual del mercado del sector de instalaciones de sonorización y las características que los eventos a realizar requieren de estos sistemas de refuerzo sonoro. Se deberá a su vez estudiar los diferentes tipos de sistemas existentes (altavoces, procesadores, amplificadores...) a disposición de los técnicos de sonido. Una vez recogida esta información, se procederá a diseñar y simular los sistemas de refuerzo sonoro elegidos con las mencionadas herramientas de simulación sonora EASE y EASE Focus. ABSTRACT. Design and simulation of the acoustic behavior of the enclosure/complex under study with installed sound reinforcement. The purpose of this final project is to design and simulate the acoustic behavior of a sports arena with the installation of an adequate systems sound radiation to its architectural features (and events to be organisated). In these simulations several design tools to compare results and get a better sound enclosure shall be used. Be carried out several designs of speaker systems for this sports arena known program EASE with sound simulation and tools that incorporates several avenues systems, filters, etc. Another sound simulation software using EASE Focus is very used professionally, more intuitive and mainly focused on sound sources groupings (clusters) of type "linear array", in one or more dimensions. It must in turn studying different types of systems (loudspeakers, processors, amplifiers ...) available to the sound technicians. Once collected this information, proceed to design and simulate the sound reinforcement systems chosen with sound simulation tools mentioned EASE and EASE Focus. As for the method and the phases of work initially be necessary to obtain information on the current state of the sector sound systems and features that make the events of these systems require sound reinforcement market.

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In this paper experimental results related to both stability an the dynamic of a asiximmetric liquid bridge between unequal disk are presented. Experiments have been performed by using a drop tower facility and the response of the liquid bridge to a sudden change of the acceleration level acting on it has bee obtained.

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The shape of the interface of a drop of liquid held by surface tension forces between two solid disks,a liquid bridge, depends on the geometry of the supporting disks, the volume of liquid and the external forces acting on the drop. Therefore, once the geometry of the supporting disks and the volume of liquid are fixed, and assuming that the value of the surface tension is known, a way to measure such external forces could be by measuring the deformation of the liquid bridge interface.

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El objetivo principal de este trabajo es profundizar en el conocimiento del fenómeno de la corrosión subpelicular inducida por contaminantes hidrosolubles en la intercara metal/pintura. La contaminación salina del substrato es una situación común en la práctica: la superficie metálica suele estar expuesta a atmósferas contaminadas antes de ser recubierta, limpieza previa del metal con abrasivos contaminados, etc. La eliminación total de estos contaminantes resulta muy difícil de conseguir incluso con las técnicas más sofisticadas de limpieza. Esta investigación se centra en la determinación del efecto de la naturaleza del contaminante y la naturaleza y espesor del recubrimiento en el proceso de corrosión subpelicular del acero. En la investigación se utilizaron dos barnices de naturaleza diferente: poliuretano y vinílico; y se aplicaron a tres espesores diferentes. Los contaminantes empleados en este trabajo fueron: NaCl, NH4C1, CaCl2, Na2S04, (NH4)2S04, NaN03, NH4N03, Ca(N03)2. Los ensayos se realizaron en una cámara de condensación de humedad permanente. Los tiempos de exposición fueron 100, 300 y 600 horas. La velocidad de corrosión se evaluó gravimétricamente, mediante la técnica de pérdida de peso. Se realizaron estudios de permeabilidad al oxígeno y al agua de películas libres de substrato, evaluación de la velocidad de corrosión de probetas sin pintar inmersas en soluciones salinas de los contaminantes seleccionados, conductividad de dichas soluciones salinas, solubilidad del oxígeno en las soluciones salinas, adherencia en seco y en húmedo a diferentes tiempos de exposición. Se aporta evidencia respecto al control ejercido en el proceso corrosivo por el oxígeno que permea a través de la película, mientras que la permeación de agua controla la pérdida de adherencia del recubrimiento. Ambas permeabilidades dependen de la naturaleza del recubrimiento y de su espesor. Se ha investigado la influencia de la naturaleza del contaminante en la intercara metal/pintura. La naturaleza del catión parece quedar enmascarada por el efecto definitivo del anión. La concentración salina ejerce asimismo un efecto importante en la corrosión subpelicular. ABSTRACT The main aim of this work is to study in depth the knowledge of underfilm corrosión induced by hydrosoluble contaminants at the metal/paint Ínterface. The saline contamination of the substrate is a common situation in practice: metallic surfaces use to be exposed to polluted atmospheres, previous cleaning of the metal with contaminated abrasives, etc. Total elimination of these contaminants is hard to obtain even with modern cleaning techniques. This research is focused in determining the effect of contaminant nature, coating nature and its thickness on the steel underfilm corrosión process. In this work we used two varnishes with different nature: polyurethane and vinyl; they were applied in three different thicknesses. The saline contaminants employed were: NaCl, NH4C1, CaCl2, Na2S04, (NH4)2S04, NaN03, NH4N03/ Ca(N03)2. The tests were carried out in a condensation humidity chamber. The period of exposure were 100, 300 and 600 hours. Corrosión rate was assessed by weight loss. Simultaneously, studies on oxygen and water permeability of free films, assessing on corrosión rate of uncoated samples immersed in saline solutions of the selected contaminants, conductivity of these solutions, oxygen solubility in saline solutions, wet and dry adhesión of the polyurethane varnish at different periods of exposure, were carried out. There is clear evidence about control on corrosión process of oxygen that passes through the coating, while the passing of water controls the loss of adhesión of the coating. Both, water and oxygen permeation, depend on the nature and thickness of the coating. It has been researched the inf luence of the nature of contaminant at the metal/paint interface. The nature of the catión seems to be "masked" by the definitive effect of the nature of anión. The saline concentration also exerts an important effect on underfilm corrosión.

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Estos apuntes de Procesado Cuántico de la Información, escritos por Francisco José Rodríguez Fortuño, están basados en las clases y el material aportado por el Prof. Miguel Angel Muriel Fernández.

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A novel database, under the acronym RISSC (Ribosomal Intergenic Spacer Sequence Collection), has been created. It compiles more than 1600 entries of edited DNA sequence data from the 16S–23S ribosomal spacers present in most prokaryotes and organelles (e.g. mitochondria and chloroplasts) and is accessible through the Internet (http://ulises.umh.es/RISSC), where systematic searches for specific words can be conducted, as well as BLAST-type sequence searches. Additionally, a characteristic feature of this region, the presence/absence and nature of tRNA genes within the spacer, is included in all the entries, even when not previously indicated in the original database. All these combined features could provide a useful documen­tation tool for studies on evolution, identification, typing and strain characterization, among others.

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Activated carbons with a highly developed mesoscale cavitation-linked structure have been prepared from natural products (e.g. peach stones) by combining chemical and physical activation processes. Characterization results show that these materials exhibit a large “apparent” surface area (∼1500 m2/g) together with a well-defined mesoporous structure, i.e. large cavities connected to the external surface through narrower mesoporous necks (cavitation effects).

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The effect of surface chemistry (nature and amount of oxygen groups) in the removal of ammonia was studied using a modified resin-based activated carbon. NH3 breakthrough column experiments show that the modification of the original activated carbon with nitric acid, that is, the incorporation of oxygen surface groups, highly improves the adsorption behavior at room temperature. Apparently, there is a linear relationship between the total adsorption capacity and the amount of the more acidic and less stable oxygen surface groups. Similar experiments using moist air clearly show that the effect of humidity highly depends on the surface chemistry of the carbon used. Moisture highly improves the adsorption behavior for samples with a low concentration of oxygen functionalities, probably due to the preferential adsorption of ammonia via dissolution into water. On the contrary, moisture exhibits a small effect on samples with a rich surface chemistry due to the preferential adsorption pathway via Brønsted and Lewis acid centers from the carbon surface. FTIR analyses of the exhausted oxidized samples confirm both the formation of NH4+ species interacting with the Brønsted acid sites, together with the presence of NH3 species coordinated, through the lone pair electron, to Lewis acid sites on the graphene layers.

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In this work, batch and dynamic adsorption tests are coupled for an accurate evaluation of CO2 adsorption performance for three different activated carbons obtained from olives stones by chemical activation followed by physical activation with CO2 at varying times, i.e. 20, 40 and 60 h. Kinetic and thermodynamic CO2 adsorption tests from simulated flue-gas at different temperature and CO2 pressure are carried out both in batch (a manometric equipment operating with pure CO2) and dynamic (a lab-scale fixed-bed column operating with CO2/N2 mixture) conditions. The textural characterization of the activated carbon samples shows a direct dependence of both micropore and ultramicropore volume on the activation time, hence AC60 has the higher contribution. The adsorption tests conducted at 273 and 293 K showed that, when CO2 pressure is lower than 0.3 bar, the lower the activation time the higher CO2 adsorption capacity and a ranking ωeq(AC20)>ωeq(AC40)>ωeq(AC60) can be exactly defined when T= 293 K. This result can be likely ascribed to a narrower pore size distribution of the AC20 sample, whose smaller pores are more effective for CO2 capture at higher temperature and lower CO2 pressure, the latter representing operating conditions of major interest for decarbonation of a flue-gas effluent. Moreover, the experimental results obtained from dynamic tests confirm the results derived from the batch tests in terms of CO2 adsorption capacity. It is important to highlight that the adsorption of N2 on the synthesized AC samples can be considered negligible. Finally, the importance of a proper analysis of characterization data and adsorption experimental results is highlighted for a correct assessment of CO2 removal performances of activated carbons at different CO2 pressure and operating temperature.

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Activated carbons prepared from petroleum pitch and using KOH as activating agent exhibit an excellent behavior in CO2 capture both at atmospheric (∼168 mg CO2/g at 298 K) and high pressure (∼1500 mg CO2/g at 298 K and 4.5 MPa). However, an exhaustive evaluation of the adsorption process shows that the optimum carbon structure, in terms of adsorption capacity, depends on the final application. Whereas narrow micropores (pores below 0.6 nm) govern the sorption behavior at 0.1 MPa, large micropores/small mesopores (pores below 2.0–3.0 nm) govern the sorption behavior at high pressure (4.5 MPa). Consequently, an optimum sorbent exhibiting a high working capacity for high pressure applications, e.g., pressure-swing adsorption units, will require a poorly-developed narrow microporous structure together with a highly-developed wide microporous and small mesoporous network. The appropriate design of the preparation conditions gives rise to carbon materials with an extremely high delivery capacity ∼1388 mg CO2/g between 4.5 MPa and 0.1 MPa. Consequently, this study provides guidelines for the design of carbon materials with an improved ability to remove carbon dioxide from the environment at atmospheric and high pressure.

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A new non-porous carbon material from granular olive stones has been prepared to be used as a reference material for the characterization of the pore structure of activated carbons. The high precision adsorption isotherms of nitrogen at 77.4 K and argon at 87.3 K on the newly developed sample have been measured, providing the standard data for a more accurate comparative analysis to characterize disordered porous carbons using comparative methods such as t- and αS-methods.

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CO2 adsorption has been measured in different types of graphitic nanostructures (MWCNTs, acid treated MWCNTs, graphene nanoribbons and pure graphene) in order to evaluate the effect of the different defective regions/conformations in the adsorption process, i.e., sp3 hybridized carbon, curved regions, edge defects, etc. This analysis has been performed both in pure carbon and nitrogen-doped nanostructures in order to monitor the effect of surface functional groups on surface created after using different treatments (i.e., acid treatment and thermal expansion of the MWCNTs), and study their adsorption properties. Interestingly, the presence of exposed defective regions in the acid treated nanostructures (e.g., uncapped nanotubes) gives rise to an improvement in the amount of CO2 adsorbed; the adsorption process being completely reversible. For N-doped nanostructures, the adsorption capacity is further enhanced when compared to the pure carbon nanotubes after the tubes were unzipped. The larger proportion of defect sites and curved regions together with the presence of stronger adsorbent–adsorbate interactions, through the nitrogen surface groups, explains their larger adsorption capacity.

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A series of carbide-derived carbons (CDC) have been prepared starting from TiC and using different chlorine treatment temperatures (500–1200 °C). Contrary to N2 adsorption measurements at −196 °C, CO2 adsorption measurements at room temperature and high pressure (up to 1 MPa) together with immersion calorimetry measurements into dichloromethane suggest that the synthesized CDC exhibit a similar porous structure, in terms of narrow pore volume, independently of the temperature of the reactive extraction treatment used (samples synthesized below 1000 °C). Apparently, these carbide-derived carbons exhibit narrow constrictions were CO2 adsorption under standard conditions (0 °C and atmospheric pressure) is kinetically restricted. The same accounts for a slightly larger molecule as N2 at a lower adsorption temperature (−196 °C), i.e. textural parameters obtained from N2 adsorption measurements on CDC must be underestimated. Furthermore, here we show experimentally that nitrogen exhibits an unusual behavior, poor affinity, on these carbide-derived carbons. CH4 with a slightly larger diameter (0.39 nm) is able to partially access the inner porous structure whereas N2, with a slightly smaller diameter (0.36 nm), does not. Consequently, these CDC can be envisaged as excellent sorbent for selective CO2 capture in flue-gas streams.