65 resultados para AlGaInP LED


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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O objetivo deste estudo in vitro foi comparar os efeitos da fotoativação pelos sistemas luz halógena e LED na adesão de braquetes ortodônticos em diferentes tempos pós-colagem (imediato, 24h e 7d). Braquetes com adesivo pré-aplicado (Gemini series; APC adhesive precoated brackets; 3M Unitek, USA) foram colados na superfície vestibular de dentes bovinos. O esmalte dos dentes foi condicionado utilizando-se o primer auto-condicionante (Transbond SEP, 3M Unitek, USA) em todos os espécimes, conforme recomendações do fabricante. Setenta e dois dentes foram divididos em 2 grupos (n=36), conforme o sistema de fotoativação (luz halógena ou LED) e sub-divididos (n=12) de acordo com o tempo pós-colagem. Para os grupos luz halógena, o tempo de fotoativação foi de 20s e para os grupos LED foi de 10s. O teste de resistência ao cisalhamento foi realizado com auxílio de uma máquina de ensaios universal nos diferentes tempos pós-colagem: imediato, 24h e 7d. O valor médio de adesão para os grupos luz halógena foi de 20,01±5,24MPa e, para os grupos fotoativados pelo sistema LED 17,35±5,07MPa, sendo estes resultados estatisticamente diferentes. Quando comparado o efeito do tempo pós-colagem, os resultados revelaram que os valores de adesão foram significantemente maiores para o tempo de 7d. O resultado do teste ANOVA 2 – fatores revelou não existir diferença estatística entre a interação sistema de fotoativação e tempos pós-colagem. O teste de Tukey mostrou que para as 4 condições experimentais nos tempos imediato e 24h, os resultados não diferiram estatisticamente, independentemente do sistema de fotoativação. Somente com relação ao grupo luz halógena-7d, os resultados mostraram diferenças estatisticamente significantes. O grupo LED-7d desempenhou comportamento intermediário entre os grupos. O índice de adesivo remanescente não revelou diferenças... (Resumo completo, clicar acesso eletrônico abaixo)

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O estágio realizado em parceria entre o Departamento de Física e Biofísica do IBB-UNESP e o Hemocentro de Botucatu da FMB-UNESP teve como objetivo desenvolver um novo equipamento de luz LED capaz de interagir com culturas celulares. Desta forma foi desenvolvido um equipamento com luz azul e luz vermelha. A luz azul é responsável por inibir o crescimento celular, a luz vermelha é responsável por aumentar o crescimento celular. O equipamento consiste de uma fonte, e dois conjuntos com três LEDs cada. A cultura celular escolhida foi a de Miemola Murino (NS1), uma linhagem que possui alta taxa de crescimento e que foi mantida em estufa e meio de cultura, (simulando condições normais de sobrevivência), sendo irradiada três vezes ao dia. As amostras foram coletadas e contadas em câmara de Neubauer. Os resultados obtidos, quando comparados com o controle, não apresentaram significativa diferença de crescimento quando irradiados com luz LED vermelho. Porém quando comparados o grupo controle com o grupo irradiado com LED azul, notou-se uma significativa redução da quantidade de células a partir do sétimo dia de irradiação. Acredita-se que a ineficácia dos LEDs vermelhos ocorreram pois utilizamos células com metabolismo bastante elevado, dificultando um aumento ainda maior da taxa de crescimento. A redução da população de células azuis ocorre pois a radiação interage com a membrana celular, causando a quebra dessa membrana e conseqüente morte da célula. Outra via para a morte é a lesão causada no DNA das células, que ocorre quando a luz azul é absorvida pela molécula

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A monoclonal antibody (mAb) is an important tool in medical biotechnology and the production of biopharmaceuticals, especially for disease diagnosis and treatment of infections, because the antibodies have a significant advantage over chemical agents used in conventional therapies . The last thirty years the technology of production of monoclonal antibodies developed mainly the technique of obtaining in vitro, but also of their production is laborious, the cost is high. A major element of the high cost of production is the fact that the long-term culture consumes a large amount of imported inputs with high added value. A major contribution of this work is to promote cell growth more quickly and efficiently. Currently, a great race to discover new technologies and techniques to synthesize new antibodies and significantly increase the production of murine mAbs. New technologies such as laser and LED are innovations and widespread in modern life, so much so that its use has proliferated worldwide, primarily in the medical field. Recent studies show a series of results from the influence of the LED light in biological tissues such as: increasing the rate of cell proliferation, increased production rate of fibroblasts, increasing the rate of synthesis of RNA and DNA synthesis of ATP, etc. To assess the contribution of the LED in the culture of Myeloma NS1murino compared to the standard procedure. - NS1 cells were provided and followed the criteria of culture medium of the Laboratory of Cellular Engineering Center of Botucatu (POPs). The same amount of cells was grown in bottles of 25 cm2 polystyrene Tissue Culture Treated, specifically marked and kept in special medium RPMI 1640 Gibco BRL  supplemented with fetal bovine serum 10%, essential amino acids and non-essential, glucose, insulin and antibiotics. It was used in LEDs Cromatek wavelength of 630nm, 475nm and 530nm. The groups were... (Complete abstract click electronic access below)

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This Graduate Work aims to exhibit the analyze of the applicability of LED technology in a real outdoor lighting situation, and this project’s illumination solution is compared with the initial proposal, the sodium vapor lamps. What is studied is an outdoor area, like the roads and parking lots of a plant. A light planning software is used for this comparison, and the results are displayed instantly, allowing rapid analysis of the project through a simulation. The medium illuminance is the same in both solutions for this case study and minimum rates set as standard were observed then the analysis are appropriate in this project. Various aspects are considered in order to obtain a comprehensive analysis of this project, such as economic, environmental and quality of lighting. LED technology in outdoor lighting is presented in its infancy, but promising. Solid state lamps show great advantages when compared with other technologies, such as discharge lamps, however there are some disadvantages tied to new products that are expected to be overcome with technological development and increased production

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This work presents the development of the External Lighting Plan UNESP in the Itapeva Campus based LED and Solar Energy. Firstly it was made a collection of data from measurements of the local transit through the Google Earth 6 software and divide the local in sectors, and then perform an analysis of characteristics and age of the site. With these data it was possible to determine the average luminance the place, in30 lux. After these procedures was possible to determine the type of sets that would perform the role of bridge lighting the kit chosen was the 20/20 Sun LED manufacturer, since it contains the luminaire with the solar panel to the pole. Therefore we determined the number of poles for each sector, whichwas72in total and. After the determination of the location of each point lighting

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Solar energy can be considered the largest source of energy available on earth and has attracted in recent decades, attention and interest for its rational use. The use of energy sources in a sustainable way is essential to the survival of future generations, due to the scarcity of natural resources and their exploitation in a disorderly way. This academic work aims to bring a possible alternative to reduce the consumption of eletrical energy, at the University of Engineering – Campus of Guaratinguetá, through the use of a photovoltaic system interconnected to the LED bulbs. For this, the necessary data for the design of the photovoltaic system componentes and their acquisition costs were obtained and three differents configurations were developed to choose the one that bests fits the studied case, considering the return time of the initial investment (payback)

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Stem cells are defined as cells capable of self-renewal and differentiation into specialized cells when submited to external signalings in the enviroment. Among adult stem cells, mesenchymal cells occupy an important position because they can differentiate into mesodermal cells such as osteoblasts, adipocytes and chondrocytes. Cell therapy consists in the use of mesenchymal stem cells (MSC) in the treatment of degenerative diseases and harmed tissue reconstruction. Due to the longstanding and costly procedure for cultivation of MSC, it was proposed the use of low power light sources, such as light emitting diodes (LED), to optimize these factors. Recent works have shown a series of results from the influence of LED light on biological tissues such as increased rate of cell proliferation, increased RNA, DNA and ATP synthesis rate. The purpose of this study is to compare the biomodulator effect of LED light set at wavelengths 630nm ± 10nm and 805nm ± 10nm on the mesenchymal stem cells proliferation. For this, the mesenchymal stem cells culture adopted the procedure used in the Departament of Animal Reproduction and Veterinary Radiology of the Faculty of Veterinary Medicine and Animal Sciences of Botucatu. MSC were obtained from an adult horse bone marrow, and isolated by density gradient separation, with the FICOLL reagent and by centrifugation. The pellet containing the stem cells was removed and these were placed in low glucose DMEM culture medium, containing 10% fetal calf serum and antibiotics. The material was observed daily by inverted microscopy for monitoring the progression of the cells and subsequently the amount of cells were counted in a Neubauer counting chamber. The amount of MSC was obtained by cell culture seeded in 24 wells culture plate and segregated into three distinct groups: Group 1 was irradiated with wavelength set at 630nm ± 10 nm, Group... (Complete abstract click electronic access below)

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Energy efficiency is an increasingly important issue due to the current scenario where increasing demand is growing faster than the energy supplied. It is important, therefore, analyze and minimize electrical system losses. This study conducts a comparison of a system formed by a photovoltaic generator feeding an LED lamp directly without steps DC-AC -DC conversion, and a system using these conversion steps for the same lamp power. Losses in conversion steps are quantified and the degradation of power quality occurred due to conversion is evaluated

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This study evaluated in vitro the shear bond strength of brackets bonded with xenon plasma arc light, light-emitting diode (LED) and conventional halogen light using different curing times. Brackets were bonded to the buccal surface of 60 human maxillary premolars allocated to five groups. In groups 1 and 2, the resin was cured with the plasma arc for three and six seconds (s), respectively; in groups 3 and 4, the LED was used for five and ten s, respectively; and in group 5, the halogen light was used for 40 s. The specimens were stored in water for 24 hours and subjected to a shear force until bracket failure. The debonding pattern was classified according to the adhesive remnant index (ARI). The results were assessed by Anova and the SNK post-hoc test. No differences were detected among groups 2, 4 and 5, which showed higher averages than groups 1 and 3, which were not different between themselves. The ARI scores showed no differences among the three types of light sources in all times tested. Plasma arc and LED lights can be used with shorter curing times, within certain limits, than conventional halogen light for bonding orthodontic brackets, without decreasing bond strength.

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The aim of this study was to compare the bleaching efficacy of 35% hydrogen peroxide and 15% hydrogen peroxide with nitrogen-doped titanium dioxide catalysed by an LED-laser hybrid light. We studied 70 patients randomized to two groups. Tooth shade and pulpal sensitivity were registered. Group 1: 15% hydrogen peroxide with nitrogen-doped titanium dioxide. Group 2: 35% hydrogen peroxide. Both groups were activated by an LED-laser light. No significant differences were seen in shade change immediately, one week or one month after treatment (p > 0.05). Differences were seen in pulpal sensitivity (p < 0.05). The use of an LED-laser hybrid light to activate 15% hydrogen peroxide gel with N_TiO2 permits decreasing the peroxide concentration with similar aesthetic results and less pulpal sensitivity than using 35% hydrogen peroxide for bleaching teeth.