Prospecção tecnológica de células fotovoltaicas para energia solar

Solar energy presents itself as an excellent alternative for the generation of clean, renewable energy. This work aims to identify technological trends of photovoltaic cells for solar energy. The research is characterized, in relation to nature, to be applied; regarding the approach is qualitative and quantitative; with respect to the objectives, it is exploratory and descriptive; concerning the methodological procedure is considered a bibliographic research with a case study in the case of solar photovoltaic sector. The development of this research began with a literature review on photovoltaic solar energy and technology foresight. Then it led to the technology mapping of photovoltaic solar cells through the analysis of articles and patents. It was later performed the technological prospecting of photovoltaic cells for solar energy through the Delphi method, as well as the construction of the current plan and future technology of photovoltaic cells for the current scenario, 2020 and 2025. The results of this research show that the considered mature technologies (silicon mono and multicrystalline) will continue to be commercially viable within the prospected period (2020-2025). Other technologies that are currently viable (amorphous silicon, cadmium telluride and copper indium selenide / Copper indium gallium diselenide-), may not submit the same condition in 2025. Since the cells of silicon nanowires, dye-sensitized and based on carbon nanostructure, which nowadays are not commercially viable, may be part of the future map of photovoltaic technologies for solar energy.

Construção de células solares de corantes fotoexcitáveis utilizando flavonóides da capsicum frutescens, pimenta malagueta

The conversion of solar energy in electric with photo-voltaic cells has been carried through exclusively with devices of semiconducting junction. To put this situation comes moving for better in them last years, thanks to a new technology of production of known solar cells as Dye Solar Cell. This proposal aims at to develop a DSC having as dye lavonoides of the Capsicum frutescens (malagueta pepper). Front is considered to evaluate the photo-voltaic parameters varies it regions of the visible specter, as well as a good efficiency of conversion

Efeito de um extrato de chrysobalanus icaco na marcação de constituíntes sanguíneos com tecnécio-99m, na morfologia de hemácias, na topologia plasmidial e na ação do cloreto estanoso no dna plasmidial

The use of radionuclides has contributed for advances in Health Sciences, to research or to the diagnosis and/or treatment of diseases. These advances have been possible with the utilization of radiopharmaceuticals labeled with technetium-99m (99mTc). Stannous chloride (SnCl2) has the main reducing agent utilized to obtain radiopharmaceuticals labeled with technetium-99m. It has been reported that several natural or synthetic drugs are capable to alter the labeling of blood constituents with 99mTc, as well as the red blood cells morphology. The aim of this study was to evaluate possible alterations of Chrysobalanus icaco extract on the labeling of blood constituents with 99mTc, on the morphology of RBC of blood of Wistar rats, on the breakage of plasmid DNA and on the effects of stannous chloride on plasmid DNA. The results showed significant (P<0.05) alteration of the labeling of blood constituents with 99mTc, as well as, modification of the morphology and morphometry (perimeter/area ratio) of the RBC in presence of the extract. These data suggest that this abajeru extract could alter the labeling of blood constituents with 99mTc by its chelating/antioxidant action and/or effects on membrane structures. Moreover C. icaco extract altered the electrophoretic profile and decreased significantly (p<0.05) the effect of SnCl2 on plasmid DNA. The results obtained in this work could indicate a dose-dependent protective action against the SnCl2 and a genotoxic effect of C. icaco extract on plasmid DNA

Expressão imuno-histoquimica de colagenase-1 e gelatinases A e B em mixomas odontogênicos e papilas de germes dentários

The odontogenic myxoma shares cellular and structural aspects with dental papilla, which has been implicated as probable origin of this neoplasm. The aim of the present study was to perform a comparative immunohistochemical analysis for the expression of collagenase-1 (MMP-1) and gelatinases A (MMP-2) and B (MMP-9) in odontogenic myxomas and dental papilla of teeth germs. Twelve cases of odontogenic myxomas and eight specimens of teeth germs were selected. It was taken into consideration the presence or absence of immunoreactivity, the pattern of immunohistochemical distribution of proteases within extracellular matrix, as well as, the number of cells revealing immunostaining for matrix metalloproteinases (MMPs). It was verified a significant difference (p<0,05) in relation to MMP-2 immunoexpression, which was observed only within extracellular matrix of myxomas. Nevertheless, MMP-1 labeling was revealed by most of the cases of odontogenic myxoma, at levels close to those observed in dental papilla. In relation to the pattern of distribution, a significant difference was obtained between specimens (p<0,05), with neoplasms predominantly exhibiting a focal pattern for MMP-1. The quantitative analysis of neoplastic cells labeled for MMPs denoted a significant difference (p<0,05), demonstrating a higher proportion of MMP-1 in comparison to MMPs-2 and -9. It can be concluded that immunohistochemical expression of MMP-1 at levels comparable to those observed in dental papilla and quantitatively superior in relation to MMPs-2 and -9, suggest an implication of this protease on extracellular matrix degradation of odontogenic myxomas. Moreover, the possibility of interactions with receptors involved in cellular adhesion, particularly with integrins, suggests a plausible function on local invasiveness of such neoplasms. Additionally, the presence of a descent immunoexpression gradient for these MMPs on odontogenic myxomas, associated to substrate specificity inherent in each enzyme, suggest the existence of a coordinated mechanism between interstitial collagenase and gelatinases A and B in order to allow an efficient degradation of extracellular matrix and local invasion by neoplastic cells

Plasticidade de células tronco mesenquimais de medula óssea de ratos na presença de meio condicionado do nervo facial e do fator de crescimento fibroblástico 2

A number of evidences show the influence of the growth of injured nerve fibers in Peripheral Nervous System (PNS) as well as potential implant stem cells (SCs) to make it more suitable for nerve regeneration medium. In this perspective, this study aimed to evaluate the plasticity of mesenchymal stem cells from bone marrow of mice in the presence of culture medium conditioned with facial nerve explants (D-10) and fibroblast growth factor-2 (FGF-2). In this perspective, the cells were cultivated only with DMEM (group 1), only with D-10(group 2), only with FGF-2(group 3) or with D-10 and FGF-2(group 4). The growth and morphology were assessed over 72 hours. Quantitative phenotypic analysis was taken from the immunocytochemistry for GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200 on the fourth day of cultivation. Cells cultured with conditioned medium alone or combined with FGF-2 showed distinct morphological features similar apparent at certain times with neurons and glial cells and a significant proliferative activity in groups 2 and 4 throughout the days. Cells cultived only with conditioned medium acquired a glial phenotype. Cells cultured with FGF-2 and conditioned medium expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200. On average, area and perimeter fo the group of cells positive for GFAP and the área of the cells immunostained for OX-42 were higher than those of the group 4. This study enabled the plasticity of mesenchymal cells (MCs) in neuronal and glial nineage and opened prospects for the search with cell therapy and transdifferentiation

Investigação da estabilidade térmica e das propriedades elétricas do TiO2 em função da dopagem com Ce(SO4)2

The metalic oxides have been studies due to differents applications as materials semiconductor in solar cells, catalysts, full cells and, resistors. Titanium dioxide (TiO2) has a high electric conductivity due to oxygen vacancies. The Ce(SO4)2.2H2O doped samples TiO2 and TiO2 pure was obtained sol-gel process, and characterized by X-ray diffractometry,thermal analysis, and impedance spectroscopy. The X-ray diffraction patterns for TiO2 pure samples shows at 700°C anatase phase is absent, and only the diffraction peaks of rutile phase are observed. However, the cerium doped samples only at 900°C rutile in the phase present with peaks of cerium dioxide (CeO2). The thermal analysis of the TiO2 pure and small concentration cerium doped samples show two steps weight loss corresponding to water of hydration and chemisorbed. To larger concentration cerium doped samples were observed two steps weight loss in the transformation of the doped cerium possible intermediate species and SO3. Finally, two steps weight loss the end products CeO2 and SO3 are formed. Analyse electric properties at different temperatures and concentration cerium doped samples have been investigated by impedance spectroscopy. It was observed that titanium, can be substituted by cerium, changing its electric properties, and increased thermal stability of TiO2 anatase structure