932 resultados para Heat pump, Solar Energy, Ambient Energy, Evaporator Collector, Collector Efficiency


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La importancia de conocer bien el entorno para un proyecto arquitectnico es que podemos adaptarlo a nuestras necesidades fisiolgicas de Confort Trmico. Podemos decir entonces que el edificio juega un papel fundamental como tcnica de control de nuestro entorno. El edificio nos debera entregar un entorno controlado para que nos sintamos bien trmicamente, considerando adems, que la arquitectura por s misma puede lograr dicho confort la mayor parte de las veces. De no ser as, los usuarios tienden a colocar elementos mecnicos, para generar fro o calor artificialmente. Es fundamental entonces que nuestros edificios, tengan una correcta interaccin con los recursos naturales del lugar para lograr dicho confort trmico. Pero lograr el Confort Trmico en todos los edificios de una ciudad como unidad, no lograr que la ciudad entera sea confortable trmicamente, ya que las complejas interacciones hacen que la problemtica se deba enfrentar como algo sistmico. Esto quiere decir, que para que una ciudad o un conjunto logren la Confortabilidad Trmica deseada por sus habitantes debiera haber sido planificada conforme a variables urbanas que interacten con el medio natural en forma eficiente. Con la observacin de ciertos conjuntos habitacionales antiguos en el interior del Valle del Elqui, Chile y de sus relaciones entre variables urbanas y naturales, queda de manifiesto ciertas caractersticas que conllevan a pensar que existi una planificacin ambiental en stos que llevaron a lograr un conjunto con caractersticas bioclimticas. Las evidencias de la existencia en primer lugar de un patrn urbanstico en dichos conjuntos habitacionales antiguos, hacen pensar que dicho patrn se tratara de un patrn bioclimtico rural planificado, lo que hace que exista un gran inters por el estudio de estos conjuntos. Hasta ahora, en Chile, los pocos estudios de Confort Trmico que existen, estn orientados a edificaciones aisladas, al Confort trmico interior de la edificacin en el mbito urbano, y en nada a Patrones Bioclimticos de Conjuntos Habitacionales en una situacin de ruralidad como a la referida en esta investigacin. Adems, los estudios referidos al clima urbano, difieren a los del clima rural, por lo que se necesitan mayores estudios an para comprender mejor la problemtica. Es por esto, que la mayora de los casos mencionados en este estudio son contextualizados al mbito urbano por carecer de otros estudios rurales. Es en este sentido que esta investigacin cobra real importancia y pretende establecer la relacin existente entre las variables morfolgicas rurales y los recursos naturales del lugar y que generan un confort trmico ideal para sus habitantes, al mismo tiempo, se analiza la existencia de un Patrn Bioclimtico en un poblado denominado Algarrobito ubicado en la cuenca del Valle del Elqui, Chile. Es en este sentido que el propsito principal de este trabajo es determinar la real existencia de un Patrn Bioclimtico que relacione la morfologa rural y edificada de los antiguos poblados pertenecientes a la cuenca del Valle de Elqui Chile con el microclima del lugar. La metodologa empleada se basa en realizar primeramente el estudio del microclima del lugar a travs de las Cartas Bioclimticas. Para ello se obtuvo informacin de datos climatolgicos de las estaciones meteorolgicas ubicadas en la cuenca del Valle de Elqui, principalmente las ms cercanas al lugar de estudio. Mediante una revisin exhaustiva de la informacin arquitectnica, as como de una labor de reconocimiento en terreno realizada en el poblado seleccionado y de la aplicacin del Climograma local, se identificaron las diferentes zonas bioclimticas del poblado antiguo y potenciales reas de estudio en el conjunto. Esta actividad incluy un estudio preliminar de la energa solar local, vientos, humedad, temperaturas y su interaccin con el conjunto, permitiendo una primera aproximacin a la problemtica del espacio exterior y las viviendas. Esto permiti en base a las condicionantes del lugar, la arquitectura verncula y los materiales descubrir un Patrn en el antiguo conjunto que permita entregar confortabilidad trmica a sus habitantes y darse cuenta tambin, que el nuevo conjunto emplazado en el sector no segua ese patrn con las disfuncionalidades que ello llevaba. Con esto qued demostrado en primer lugar la existencia de un Patrn Bioclimtico rural, los beneficios del patrn, la importancia de ste como causante de Confortabilidad Trmica del conjunto, y por ende de mejor eficiencia energtica, as como tambin, que el nuevo conjunto no sigue para nada este Patrn, pero que existe tambin la posibilidad de rectificacin y por supuesto, que los nuevos desarrollos residenciales del Valle del Elqui, puedan planificarse en base al patrn bioclimtico descubierto. ABSTRACT Knowing the environment of an architectonic proyect is really important for adjusting it to our physiological needs of Thermal Comfort. So we can say that the building plays a key role as a technique of control of our environment. The building should give us a controlled environment to make us feel good thermally, and it usually can reach pleasurable temperatures by itself. If it isn't like that, people cooled or heated the ambience with mechanical elements. So a correct interaction between the buildings and natural resources is important to reach a thermal comfort. But achieving Thermal Comfort in all the buildings of a city as a unit will not achieve the whole city is thermally comfortable, because the complex interactions cause the problem needs to be solved as something systemic. This means that for a city or a set reach the Thermal Comfortability desired by its inhabitants, it should have been planned according to the urban variables that interact with the natural environment efficiently. Observing some old housing complexes in Elqui Valley, Chile, and the relationships between their natural and urban variables, some features lead to think that the environmental planning in these led to achieve a set with bioclimatic features. First, the evidences about the existence of an urban pattern in those old housing complexes, make thinking that the pattern would be a planned urban pattern, which generates interest in its study. In Chile, there have been few studies about Thermal Comfort, oriented to isolated buildings and indoor thermal comfort, but Bioclimatic Urban Patterns haven't been studied at all. In this sense, this investigation acquires a real importance and pretends to establish the relationship between urban variables and natural resources of the place that generates a good thermal comfort for its habitants. At the same time, the existence of a Bioclimatic Urban Pattern in Algarrobito, located in Elqui Valley basin, Chile, is analized. It is in this sense that the main purpose of this work is to determine the real existence of a Bioclimatic Urban Pattern, that links the urban and constructive form of the old villages of it with its microclimate. The methodology used is based on performing first the study of the microclimate of the place through the Bioclimatic Cards. To do this, weather stations, located in Elqui valley, near the place that was studied, were used to obtain information of climatological data. The different bioclimatic zones to the old town and potential areas of study in the set were identified, through an exhaustive review of the architectural information, a field reconnaissance work performed on the selected town and the application of the Local Climograph. This activity included a preliminary study of the local solar energy, the winds, the moisture, the temperatures, and their interaction with the set, allowing a first aproximation to troubles of outer space and housing. This allowed, based on the conditions of the place, vernacular architecture and materials, discovering an urban pattern in the old set, which allowed to give thermal comfort to its inhabitants and realize that the new set of the place did not follow this pattern, with the dysfunctions that it carried. These points demonstrated, in first place, the existence of a Bioclimatic Urban Pattern, the benefits of it, the importance of it as a cause of Thermal Comfortability, and therefore a better efficiency of energy, also that the new set doesnt follow this Pattern at all, but that the posibility of rectification exists and, of course, that the new residencial development in Elqui Valley can be planned based on bioclimatic pattern discovered.

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A full Hybrid lighting-CPV prototype has been assembled. This new concept mixes a classical CPV module with the production of light for illumination without a double conversion (solar energy to electricity and electricity to light) allowing a higher efficiency to the whole system. The present prototype is based on a commercial CPV module that has been adapted in order to be hybrid, adjusting the receivers to pass the fibers into the module, inserting a holder to adjust x,y and z position of the fibers and changing the original parquet of lenses by a bifocal one composed most of the original lenses and the inclusion of other lenses in the position of the corners. Results show that with a minimal loss in the CPV part, a luminous flux is obtained that can be used to illuminate. Adding an additional electrical lamp and a light sensor that enables this lamp when no light from the sun is received, a 38% saving on lighting electricity is expected in Madrid during a year.

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Phenomena of overirradiance have been pointed all over the World. This note presents the most extreme enhancement event reported in Brazil, which contains an irradiance reading of 1590 W/m2 measured in So Paulo (latitude 2332S) at relatively low altitude (760 m a.s.l.).

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A key step in the conversion of solar energy into chemical energy by photosynthetic reaction centers (RCs) occurs at the level of the two quinones, QA and QB, where electron transfer couples to proton transfer. A great deal of our understanding of the mechanisms of these coupled reactions relies on the seminal work of Okamura et al. [Okamura, M. Y., Isaacson, R. A., & Feher, G. (1975) Proc. Natl. Acad. Sci. USA 88, 34913495], who were able to extract with detergents the firmly bound ubiquinone QA from the RC of Rhodobacter sphaeroides and reconstitute the site with extraneous quinones. Up to now a comparable protocol was lacking for the RC of Rhodopseudomonas viridis despite the fact that its QA site, which contains 2-methyl-3-nonaprenyl-1,4-naphthoquinone (menaquinone-9), has provided the best x-ray structure available. Fourier transform infrared difference spectroscopy, together with the use of isotopically labeled quinones, can probe the interaction of QA with the RC protein. We establish that a simple incubation procedure of isolated RCs of Rp. viridis with an excess of extraneous quinone allows the menaquinone-9 in the QA site to be almost quantitatively replaced either by vitamin K1, a close analogue of menaquinone-9, or by ubiquinone. To our knowledge, this is the first report of quinone exchange in bacterial photosynthesis. The Fourier transform infrared data on the quinone and semiquinone vibrations show a close similarity in the bonding interactions of vitamin K1 with the protein at the QA site of Rp. viridis and Rb. sphaeroides, whereas for ubiquinone these interactions are significantly different. The results are interpreted in terms of slightly inequivalent quinoneprotein interactions by comparison with the crystallographic data available for the QA site of the two RCs.

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Bacterial photosynthesis relies on the interplay between light harvesting and electron transfer complexes, all of which are located within the intracytoplasmic membrane. These complexes capture and transfer solar energy, which is used to generate a proton gradient. In this study, we identify one of the factors that determines the organization of these complexes. We undertook a comparison of the organization of the light-harvesting complex 1 (LH1)/reaction center (RC) cores in the LH2 mutant of Rhodobacter sphaeroides in the presence or absence of the PufX protein. From polarized absorption spectra on oriented membranes, we conclude that PufX induces a specific orientation of the reaction center in the LH1 ring, as well as the formation of a long-range regular array of LH1-RC cores in the photosynthetic membrane. From our data, we have constructed a precise model of how the RC is positioned within the LH1 ring relative to the long (orientation) axis of the photosynthetic membrane.

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While the last 50 years of agriculture have focused on meeting the food, feed, and fiber needs of humans, the challenges for the next 50 years go far beyond simply addressing the needs of an ever-growing global population. In addition to producing more food, agriculture will have to deal with declining resources like water and arable land, need to enhance nutrient density of crops, and achieve these and other goals in a way that does not degrade the environment. Biotechnology and other emerging life sciences technologies offer valuable tools to help meet these multidimensional challenges. This paper explores the possibilities afforded through biotechnology in providing improved agronomic input traits, differentiated crops that impart more desirable output traits, and using plants as green factories to fortify foods with valuable nutrients naturally rather than externally during food processing. The concept of leveraging agriculture as green factories is expected to have tremendous positive implications for harnessing solar energy to meet fiber and fuel needs as well. Widespread adaptation of biotech-derived products of agriculture should lay the foundation for transformation of our society from a production-driven system to a quality and utility-enhanced system.

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Materials with high electrical conductivity and optical transparency are needed for future flat panel display, solar energy, and other opto-electronic technologies. InxCd1-xO films having a simple cubic microstructure have been grown on amorphous glass substrates by a straightforward chemical vapor deposition process. The x = 0.05 film conductivity of 17,000 S/cm, carrier mobility of 70 cm2/Vs, and visible region optical transparency window considerably exceed the corresponding parameters for commercial indium-tin oxide. Ab initio electronic structure calculations reveal small conduction electron effective masses, a dramatic shift of the CdO band gap with doping, and a conduction band hybridization gap caused by extensive Cd 5s + In 5s mixing.

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The heart of oxygenic photosynthesis is photosystem II (PSII), a multisubunit protein complex that uses solar energy to drive the splitting of water and production of molecular oxygen. The effectiveness of the photochemical reaction center of PSII depends on the efficient transfer of excitation energy from the surrounding antenna chlorophylls. A kinetic model for PSII, based on the x-ray crystal structure coordinates of 37 antenna and reaction center pigment molecules, allows us to map the major energy transfer routes from the antenna chlorophylls to the reaction center chromophores. The model shows that energy transfer to the reaction center is slow compared with the rate of primary electron transport and depends on a few bridging chlorophyll molecules. This unexpected energetic isolation of the reaction center in PSII is similar to that found in the bacterial photosystem, conflicts with the established view of the photophysics of PSII, and may be a functional requirement for primary photochemistry in photosynthesis. In addition, the model predicts a value for the intrinsic photochemical rate constant that is 4 times that found in bacterial reaction centers.

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This report covers SERI research activities on solid-state theory, high-efficiency cells, thin-film cells, silicon purification, silicon crystallization, thick-film technology, surface and interface analysis, and growth of GaAs and related compounds by metal-organic chemical vapor desposition.

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The purpose of this research program is to investigate the photoelectronic properties of zinc phosphide (ZnP in single crystal form, in thin-film form, and in heterojunctions in which ZnP forms one of the elements. This research will be directed toward understanding the role of crystalline defects and impurities in ZnP, the nature of the electronic charge transport in single crystal and thin-film material, and the properties of photovoltaic heterojunctions involving ZnP. The scope of the program extends from basic investigations of materials properties on single crystals to the preparation and characterization of all-thin-film heterojunction divices. One of the principal motivations behind this research program is the realization that ZnP is a relatively uninvestigated yet ideal component for photovoltaic heterojunction use in solar energy conversion. The proposed program will concentrate on the basic materials problems involved with ZnP, providing the kind of information needed for other more developmental programs directed toward actual practical cells.

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"Work Performed Under Contract No. AC02-77CH00178."

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"Work Performed Under Contract No. AC02-77CH00178."