Made available in DSpace on 2014-06-11T19:24:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-08-31Bitstream added on 2014-06-13T19:51:22Z : No. of bitstreams: 1 caceresbenitez_p_me_arafo.pdf: 539913 bytes, checksum: 4b2674880d3cfaa5af955bceb1ed75eb (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo desta pesquisa foi avaliar a influência de várias temperaturas sobre os valores de microdureza de topo e base de uma resina composta fotopolimerizável comercialmente disponível, variando o tipo de fonte de luz (LEDs e lâmpada halógena). As temperaturas testadas foram 25, 35, 45, 55, 65, 80, 90 e 100º C. A resina composta utilizada foi a Z100 (3M). Com o auxílio de uma matriz metálica foram confeccionados 3 corpos-de-prova de 2 mm de espessura e 9,8 mm de diâmetro para cada temperatura. Os corpos-de-prova foram polimerizadas LEDs (60 s) ou lâmpada halógena (40 s) enquanto eram submetidas às diferentes temperaturas, após a polimerização as amostras foram armazenadas a seco, em estufa a 37º C. Após 24 horas as amostras foram submetidas ao teste de microdureza Vickers no topo e na base. Baseados nos resultados conclui-se que com a elevação da temperatura aumentou o valor da dureza Vickers com correlação linear positiva e com ambos aparelhos; o valor da dureza de topo foi sempre superior à dureza de base independentemente da fonte de luz ou temperaturas empregadas; o aparelho de luz halógena só se mostrou superior à fonte de LEDs na região de base dos corpos-de-prova. / The aim of this research was to evaluate the influence of several temperatures on the microhardness values of top and base of a light curing composites resin commercially available, varying the type of light source (LEDs and halogen lamp). The tested temperatures were 25, 35, 45, 55, 65, 80, 90 and 100º C. The composite resin used was Z100 (3M). With the aid of a metallic mould were made three samples of 2 mm of thickness and 9,8 m diameter for each temperature. The samples were light cure while they where submitted to the different temperatures with LEDs (60 s) and halogen lamp (40 s), after the polymerization the samples were dry stored in a stove at 37º C. After 24 hours, the samples were submitted to the Vickers microhardness test in the top and in the base. Based on the results it was concluded that with the elevation of the temperature increased the Vickers hardness value with positive linear correlation on both devices. The hardness value of the top was always superior to the base hardness, independently of the light source or used temperatures. The halogen lamp source was superior to the source of LEDs in the area of base of the samples.

Made available in DSpace on 2014-06-11T19:24:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-01Bitstream added on 2014-06-13T18:20:14Z : No. of bitstreams: 1 kabbach_w_me_arafo.pdf: 487757 bytes, checksum: 39ad2a660914605ee0e6795c22edba78 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do presente estudo foi avaliar in vitro a variação de temperatura e a microdureza Knoop superficial do esmalte durante o processo de clareamento dental com peróxido de hidrogênio a 35% sob irradiação da luz halógena com o comprimento de onda de 400 a 500nm (HL), luz emitida por diodo com comprimento de onda de 460 de 480 (LED) e laser de diodo (DL) de alta intensidade e comprimento de onda de 810nm, em dentes humanos extraídos. Inicialmente investigou-se a variação de temperatura superficial através da termografia de infravermelho e a temperatura do interior da câmara pulpar por meio de termopares em incisivos inferiores humanos, quando submetidos ao clareamento dental com peróxido de hidrogênio a 35% nas cores vermelha (HP) e verde (HPM) irradiados por: HL e LED. Quatro grupos (n=10) foram divididos de acordo com o gel clareador e a fonte de luz. Os resultados foram submetidos à análise de variância e teste de Tukey (p < 0,05). Os valores médios e desvios padrão do aumento de temperatura dentro da câmara pulpar com a HL foram de 4.4 ± 2.1 °C para HP, e 4.5 ± 1.2 °C para HPM; enquanto que nos grupos usando LED, foram 1.4 ± 0.3 °C para HP, e 1.5 ± 0.2 °C para HPM. Para todas as temperaturas superficiais a variação máxima dos grupos irradiados com HL foi 6.5 ± 1.5 °C para HP, e 7.5 ± 1.1 °C usando HPM; enquanto para os grupos usando LED, foram 2.8 ± 0.7 °C usando HP, e 3 ± 0.8 °C para HPM. Não houve diferença estatística entre o aumento da temperatura pulpar e superficial entre os grupos usando os diferentes géis (p < 0,05). As médias de temperatura foram significativamente maiores para os grupos usando HL quando comparados com aqueles irradiados com LED (p < 0,05). Ainda foi investigada a variação de temperatura superficial e assim determinado o tempo de demora para ser atingida a variação crítica de temperatura... / The objective of this in vitro study was to evaluate the variation of temperature and Knoop microhardness on enamel surface during the bleaching process whith 35% hydrogen peroxide under irradiation by halogen light whit the wavelength of 400 to 500nm (HL), LED whit the wavelength of 460 to 480nm and high intensity diode laser LED whit the wavelength of 810nm (LD) on extracted human teeth. Initially were investigated the variation of surface temperature (infrared thermography) and the temperature of the interior of the pulp chamber (thermocouples) in human mandibular incisors when subjected to dental bleaching with 35% hydrogen peroxide in the colors red (HP) and green(HPM) irradiated by: HL and LED. Four groups (n = 10) were divided according to the bleaching gel and light source. The results were submitted to the analysis of variance and Tukey test (p < 0.05). The mean values and standard deviations of the temperature increase inside the chamber pulp with HL were 4.4 ± 2.1 °C using HP and 4.5 ± 1.2 °C using HPM; while in LED groups, were 1.4 ± 0.3 °C to HP, and 1.5 ± 0.2 °C using HPM. For all surface temperatures, the maximum variation of the groups irradiated with HL was 6.5 ± 1.5 °C to HP and 7.5 ± 1.1 °C using HPM; while for the groups using LED, were 2.8° ± 0.7 °C using HP, and 3 ± 0.8 °C for HPM. There were no statistical difference between the increase of pulp and superficial temperature between groups using the various gels (p < 0.05). Mean temperatures were significantly higher for groups using HL compared with those irradiated with LED (p < 0.05). Was investigated the variation of surface temperature and thus given the time-delay to hit the critical variation of temperature (5.5 °C for the pulp chamber and 10 °C for periodontal). Forty-five human inferior incisors were divided into 3 groups and submitted to dental bleaching using...(Complete abstract, click electronic access below)

Made available in DSpace on 2014-10-09T12:35:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:34Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:35:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:34Z (GMT). No. of bitstreams: 0 / Lasers operando nas regiões espectrais do azul e do amarelo-laranja foram recentemente requisitados pelo mercado de aplicações quer para melhorar as tecnologias já conhecidas ou para possibilitar a criação de novas. Isso é devido às propriedades destas regiões espectrais, com o azul trazendo características tais como fótons de alta energia e feixes limitados por difração menores, enquanto a faixa do amarelo-laranja é ainda uma região espectral difícil de se atingir e não foi totalmente acessada ou nem mesmo acessada por fontes de luz laser eficientes. Aplicações dos lasers azuis são encontradas em tecnologias de alta densidade de armazenamento, displays a laser, sistemas LIDAR, pinças ópticas e uma longa série de aplicações que exigem alta precisão. Os lasers amarelo-laranja também têm aplicações importantes, destacando-se aplicações em cirurgia oftalmológica a laser, em displays de cores reais e como estrela guia (excitando linhas de sódio na atmosfera). A investigação de lasers de quase três níveis e laser Raman de Nd:YLF foi realizada neste trabalho. A finalidade é de propor fontes laser de alta potência e eficientes emitindo no azul e no amarelo para suprir as aplicações. Eficiência e potências de saída da ordem de Watt foram demonstradas para um laser de Nd:YLF emitindo em 908 nm assim como no segundo harmônico em 454 nm. Além disso, lasers Raman de Nd:YLF/BaWO4 e Nd:YLF/KGW foram demonstrados atingindo alguns Watts de potência de saída em regime quasi-CW e CW, com boas qualidades de feixe (M2 2) e em oito comprimentos de onda diferentes: 1147 nm, 1163 nm, 1167 nm , 549 nm, 552 nm, 573 nm, 581 nm e nm 583. Por fim, uma luminescência azul originada em alguns cristais Raman, durante a oscilação Stokes, teve sua origem e seus efeitos colaterais para lasers (perdas e calor adicionais) minuciosamente caracterizados. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

When an item is submitted to a crime laboratory, the first step in analysis is to examine the item under white light. The next step in examination often involves the use of alternate light sources (ALS) to search for potential biological evidence. Dark adaptation has been suggested as a method to maximize benefits from fluorescent evidence examinations. Dark adaptation refers to the ways the human eye adapts to low light conditions through pupil dilation and rod cell activation. This study evaluates the Crime-lite Eye®, a device designed to help forensic scientists determine their level of dark adaptation before commencing an ALS examination. When tested, the use of the Crime-lite Eye® device resulted in 14% more visualization of fluorescence and 11% more accuracy in pattern recognition, though results were not statistically significant. Since results were more accurate overall, however, and because allowing for a period of dark adaptation would not significantly delay investigation efforts, laboratories should consider implementing a dark adaptation period into their workflow during fluorescent examinations. Additionally, some ALS manufacturers have begun to include a strobing feature in their devices, such as the GlowTorch FN Forensic Light™. It is known from studies on human attention that flickering stimuli are very effective at capturing attention. Any material fluorescing in response to a strobing ALS would look to the examiner to be suddenly appearing and disappearing as a series of sudden onset stimuli, potentially making weak fluorescence easier to see. Participants in this study were asked to examine four plaid shirts in ambient light conditions and dark conditions, while using either a solid ALS or a strobing ALS. Participants were slightly more accurate while using the strobing ALS device (90% vs 82% in ambient light conditions and 93% vs 92% in dark lighting conditions). However, many of them reported feeling eye strain and annoyance while using the strobing feature. As the change in accuracy was not statistically significant, there is no evidence at present that suggests forensic laboratories need to implement a strobing ALS device into their protocols.

Optogenetics, a revolutionary technique that utilizes light-sensitive proteins called opsins to control neuronal activity, has transformed the field of neuroscience by providing unprecedented precision in the study of neural circuits and behavior. This thesis focuses on the application of optogenetics in Drosophila melanogaster research, aiming to advance our understanding of neural circuits and behavior through the development of adaptive light sources, and a set of homemade tools to simplify the design of optogenetic experiments, combining biology, engineering and computer science approaches. The first goal of this research was to find new, low-cost, and versatile ways to perform optogenetic experiments. This led us to the exploration and characterization of smartphone displays as light sources for optogenetic stimulation. By utilizing smartphone displays, the activation and inhibition of various cell types, including motoneurons, muscles, sensory neurons, and multidendritic neurons, were achieved in Drosophila larvae and flies. This approach expands the possibilities of optogenetic research, making it accessible for students and researchers to easily perform experiments with small animals, at high temporal and spatial resolution, or even the light and spectral requirements of novel light-sensitive proteins. To facilitate optogenetic experiments, software tools were developed to accurately quantify light spatial distribution and analyze larval behavior. Spatial light distribution simulations provided insights into the emitted light from displays aiding us in the planning and understanding of the experimental results, tailored for light emitted by displays, and based on physical measurements rather than on simple assumptions on light spreading. Furthermore, an automatic feature extraction tool enhanced the understanding of larval responses to light stimuli, capturing key behavioral events such as stops, sweeps, turns, and runs. This aids us in extracting a high number of behavioral characteristics, automatically, accurately and in less time compared to manual behavioral feature definition. The manipulation of complex light patterns using smartphone displays allowed us to design experiments for guiding larval movement. By integrating smartphone optogenetics, spatial light distribution simulations, and behavior feature extraction techniques, responses of larvae to different light profiles were elucidated, contributing to the understanding of larval behavior and its underlying mechanisms, particularly investigating the nociceptive adaptation of larvae in different gradients of light, showing similar adaptability in Drosophila larvae as in humans. Additionally, investigations into the control of larval feeding behavior using optogenetics shed light on the influence of non-neuronal cells, specifically the salivary glands, on feeding regulation. Manipulating these glands through optogenetic techniques resulted in significant changes in larval feeding behavior, emphasizing the need to consider the contribution of other organs alongside neural control when studying animal behavior, and demonstrating for the first time optogenetically driven cannibalism in larvae. Moreover, the integration of bicolored Organic LEDs (OLEDs) with bidirectional optogenetics opens new avenues for studying neural circuits and developing therapeutic interventions for neurological disorders. The precise control of larval motoneurons and locomotor systems using these AC/DC OLEDs holds promise for investigating the role of single neurons in complex behaviors and potentially restoring locomotion in patients with spinal cord injuries. This thesis contributes to the field of optogenetics by advancing the understanding of larval behavior and its modulation through light stimulation. The novel adaptive light sources, tools for analysis, and insights gained from the experiments provide a framework for further exploration of neural circuits and behavior in Drosophila melanogaster and other small animal models.

M. Tech. (Power Engineering, Faculty of Engineering and Technology), Vaal University of Technology / In view of the energy consumption problems, an impact study, extensive laboratory tests and an investigation towards comparable energy saving light sources was carried out on the light sources identified in the survey conducted at the Vaal University of Technology (VUT), Vanderbijlpark campus. Three types of identified incandescent light sources were purchased and extensively tested in order to obtain viable statistical data on the life span, luminance delivered per unit, power consumption and economic effect, as well as identifying relevant energy efficient light sources for replacement purposes. A suitable computerised maintenance program has been developed to be introduced to the VUT that currently does not have a lighting system maintenance program. The case study was located within the empirical-analytical paradigm, using quantitative data. The identified aims and goals place the empirical part of the study in the category of implementation evaluation research that provides an overview of a maintenance plan.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-06-22T14:48:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_manoel_urbano_ferreira_junior.pdf: 1258852 bytes, checksum: 5c71b7b318b75585b07278fdbe9a7971 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-06-22T20:37:33Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_manoel_urbano_ferreira_junior.pdf: 1258852 bytes, checksum: 5c71b7b318b75585b07278fdbe9a7971 (MD5) / Made available in DSpace on 2017-06-22T20:37:33Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_manoel_urbano_ferreira_junior.pdf: 1258852 bytes, checksum: 5c71b7b318b75585b07278fdbe9a7971 (MD5) Previous issue date: 2015-04-08 / Sem bolsa / A utilização da técnica de micropropagação de plantas tornou-se uma ferramenta comum entre os produtores de plantas certificadas. Porém ainda se utiliza o sistema de micropropagação convencional de forma ampla sem se dar a devida importância ao sistema de imersão temporária (SIT). O objetivo do presente trabalho é apresentar uma alternativa de diminuição dos custos de produção e simplificação dos trabalhos de plantas in vitro, através da montagem e utilização de biorreatores de imersão temporária e utilização de um novo modelo de válvula duplo solenoide de cinco vias de centro aberto negativo. No presente trabalho, apresenta-se um modelo de SIT, construído de forma artesanal, que quando comparado a equipamentos similares manufaturados apresenta resultados de produtividade equivalente provando ser um equipamento de grande utilidade na automação para produção de plantas in vitro. Ao mesmo tempo, desenvolveu-se um microbiorreator, utilizando recipientes de vidro com pequena capacidade, com a finalidade de se trabalhar materiais vegetais com pouca disponibilidade de explantes, o qual poderá ser utilizado em pesquisa científica, com sucesso, conforme corroborado em trabalhos preliminares com as culturas de amora-preta, framboesa e macieira. A principal espécie vegetal utilizada nos experimentos com os biorreatores, batata-doce, apresenta um grande apelo popular devido a sua contribuição alimentar como fornecedora de carboidratos, aminoácidos e vitaminas e não tinha ainda sido testada neste sistema de micropropagação. Os resultados obtidos com os biorreatores foram similares às taxas de multiplicação em sistema convencional, demonstrando que os protocolos para utilização do SIT precisam ser otimizados, principalmente quanto ao tempo e número de imersões, composição dos meios de cultura e densidade de fluxo de fótons. No sistema convencional, não foi observado influência diferencial entre as lâmpadas fluorescentes branca-fria e LED e 7,5g L-1 de sacarose apresentou resultado similar a 15 e 30g L-1 nas variáveis estudadas, indicando que esta espécie é pouco exigente quanto a adição externa de açúcares no meio de cultura, sendo talvez um material vegetal indicado para estudos de micropropagação fotoautotrófica. Finalmente, o equipamento agora disponível no Laboratório de Cultura de Tecidos de Plantas da UFPel poderá ser utilizado no desenvolvimento de novas pesquisas cientificas relacionadas à fisiologia, anatomia e produção de metabólitos secundários. / The use of plant micropropagation technique has become a common tool between producers of certified plants. But the conventional micropropagation system is still broadly used without giving due importance to the temporary immersion system (TIS). The objective of this study is to present a cheaper alternative production costs and simplification of in vitro plants of work, through the assembly and use of temporary immersion bioreactors and use of a new double solenoid valve model five open center routes negative. In this study, we present a model of TIS, built by hand, that when compared to similar manufactured equipment showed results with equivalent productivity, proving to be a very useful equipment in automation for production of in vitro plants. At the same time, we developed a microbiorreactor using glass containers of small capacity, in order to work with low availability of vegetal material explants , which can be used for scientific research successfully, as confirmed in preliminary studies with cultures of blackberry, raspberry and apple. The main plant specie used in this experiments with the bioreactor, sweet potato, has great popular appeal due to its contribution as a supplier of food carbohydrates, amino acids and vitamins and had not yet been tested in this micropropagation system. The results obtained with multiplication in bioreactors were similar to rates in conventional system, showing that the use of TIS protocols must be optimized, especially with regard to the time and number of immersion, composition of culture media and photon flux density. With the conventional system, there wasn't observed influence differential between white-cold fluorescent lamps and LED and 7.5 g L-1 sucrose showed a similar result to 15 and 30 g L-1 in the variables studied, indicating that this species is not very exigent about external addition of sugars in the culture medium, and perhaps it could be a plant material suitable for studies of photoautotrophic micropropagation. Finally, the equipment now available in Plant Culture Laboratory may be used in the development of new scientific research related to physiology, anatomy and production of secondary metabolites.

Thesis (Ph.D.); Submitted to Iowa State Univ., Ames, IA (US); 12 Dec 2003. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2100" Gang Li. 12/12/2003. Report is also available in paper and microfiche from NTIS.

Made available in DSpace on 2014-10-09T12:28:33Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:00Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:08/00723-4