556 resultados para Foto
Resumo:
Currently we live in an increasingly visual world, where images are used as non-verbal language for different interests. Considering the ease of getting a photograph and the many ways that it can find, understand that this language can be a means of reading the geographic space, appearing as text and not only as illustration for teaching geography. Thus, this work aims to try an approach between artistic photographic language and geographic scientific language, observing how different groups with different ages read the geographic space through photographs. Focusing on the school environment, we have in mind the need to work with the various pictorial means that are increasingly present in textbooks of geography teaching. Here then, as proposed, a trial in which students from elementary and secondary education will shoot what for them is the city. The analysis will be performed observing possible differences and / or common aspects in the photographs according to the age group of students groups, trying to discover how the geographic space is being read by students through images and how this trial can contribute to the basic education of discipline geography
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Plastic solar cells bear the potential for large-scale power generation based on flexible, lightweight, inexpensive materials. Since the discovery of the photo-induced electron transfer from a conjugated polymer (electron-donor) to fullerene or its derivatives molecules (electron-acceptors), followed by the introduction of the bulk heterojunction concept which means donors and acceptors blended together to realize the fotoactive layer, materials and deposition techniques have been extensively studied. In this work, electrochemical-deposition methods of polymeric conductive films were studied in order to realize bulk heterojunction solar cells. Indium Tin Oxide (ITO) glass electrodes modified with a thin layer of poly(3,4-ethylenedioxythiophene) (PEDOT) were electrochemically prepared under potentiodynamic and potentiostatic conditions; then those techniques were applied for the electrochemical co-deposition of donor and acceptor on modified ITO electrode to produce the active layer (blend). For the deposition of the electron-donor polymer the electropolymerization of many functionalized thiophene monomers was investigated while, as regards acceptors, fullerene was used first, then the study was focused on its derivative PCBM ([6,6]-phenyl-C61-butyric acid methyl ester). The polymeric films obtained (PEDOT and blend) were electrochemically and spectrophotometrically characterized and the film thicknesses were evaluated by atomic force microscopy (AFM). Finally, to check the performances and the efficiency of the realized solar cells, tests were carried out under standard conditions. Nowadays bulk heterojunction solar cells are still poorly efficient to be competitively commercialized. A challenge will be to find new materials and better deposition techniques in order to obtain better performances. The research has led to several breakthroughs in efficiency, with a power conversion efficiency approaching 5 %. The efficiency of the solar cells produced in this work is even lower (lower than 1 %). Despite all, solar cells of this type are interesting and may represent a cheaper and easier alternative to traditional silicon-based solar panels.
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Scan von Monochrom-Mikroform
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Scan von Monochrom-Mikroform
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Scan von Monochrom-Mikroform
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Scan von Monochrom-Mikroform
