Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo deste trabalho foi avaliar o efeito de um diodo emissor de luz (LED) Smart Lite PS (Dentsply) e da lâmpada halógena convencional Curing Light XL 3000 (3M) na efetividade de polimerização do compômero Dyract Ap (Dentsply) e da resina composta TPH Spectrum (Dentsply) por meio de testes de microdureza Knoop, resistência à compressão e resistência flexural e caracterização dos materiais. Foram confeccionadas 100 amostras e divididas em 12 grupos de acordo com o teste aplicado, a luz de polimerização e o material utilizado. A lâmpada halógena convencional selecionada, Curing Light XL 3000 (3M), tinha intensidade de 470mW/cm2 e comprimento de onda entre 400 e 510nm; o LED Smart Lite PS (Dentsply) tinha intensidade de 950mW/cm2 e comprimento de onda entre 450 e 490nm. O tempo de fotopolimerização para cada incremento com 2mm de espessura foi de 40 s. para a lâmpada halógena convencional e 10 s. para o LED. Para os testes de microdureza Knoop foram confeccionadas 20 amostras numa matriz cilíndrica com 8,0mm de diâmetro e 2,0mm de altura. As leituras da microdureza foram realizadas nas superfícies superiores e inferiores das amostras utilizando um microdurômetro Micromet 2003, com uma carga de 50 gf por 15 s. Para o teste de resistência à compressão foram confeccionadas 40 amostras numa matriz cilíndrica com 4,0mm de diâmetro e 8,0mm de altura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 500Kgf e velocidade de carregamento de 0,5 mm/min. Para o teste de resistência flexural foram construídas 40 amostras numa matriz em forma de caixa com 25,0mm de comprimento, 2,0mm de altura e 2,0mm de largura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 50Kgf e velocidade de carregamento de 0,5 mm/min. Cada material foi caracterizado pela termogravimetria, espectrometria no infravermelho, espectrometria de ressonância magnética nuclear, teor de cinzas, fluorescência de raios-X e microscopia eletrônica de varredura. Os resultados foram tratados por ANOVA e teste de SNK (p<0,05). Os resultados de microdureza Knoop, resistência à compressão e resistência flexural providos pela luz halógena foram melhores que os dos LED. A resina composta apresentou melhor performance que o compômero em todos os testes. / The goal of this work was to evaluate the effects of the blue light emitting diodes (LEDs) Smart Lite PS (Dentsply) and the conventional halogen lamp Curing Light XL 3000 (3M) on the polymerization effectiveness of the Dyract Ap compomer (Dentsply) and the TPH Spectrum composite resin (Dentsply) by the Knoop microhardness, compressive strength, flexural strength and material characterization tests. A hundred samples were prepared and divided into 12 groups according to the test applied, the polymerization light and the material. The conventional halogen lamp light had power of 470mW/cm and wavelength between 400 and 510nm; the LED light had power of 950mW/cm and wavelength between 450 and 490nm. The polymerization time for each material 2mm buildup was 40 seconds for the conventional halogen lamp and 10 seconds for LED. For the Knoop microhardness tests the 20 samples were cylinder shaped, 8mm diameter and 2mm height. The hardness was read in the upper and lower side of the samples by a micrometer (Micromet 2003), with 50 gf for 15 seconds. For the compressive strength test the 40 samples were cylinder shaped, 4mm diameter and 8mm height. The strength was measured in an universal testing machine Emic DL 10.000 with 500Kgf and cross-head speed of 0,5 mm/min. For the flexural strength test the 40 samples were box shaped, 25mm length, 2mm width and 2mm height. The strength was measured in an universal testing machine Emic DL 10.000 machine with 50Kgf and cross-head speed of 0,5 mm/min. Each material was characterized by Thermogravimetry, FT-IR analysis, Nuclear Magnetic Resonance, Ash Content Test, X-Ray Fluorescence and Scanning Electron Microscopy. The results were treated by ANOVA and SNK tests (p<0,05). The Knoop microhardness, compressive strength and flexural strength results provided by the halogen light lamp were better than the LED ones. The composite resin performed better than the compomer in all mechanical tests.

O clareamento dental é um procedimento que está diretamente relacionado à estética dental e cabe ao profissional de odontologia conhecer e dominar os diferentes materiais, métodos de ativação e técnicas de clareamento. Este estudo ¨In Vitro¨ avaliou comparativamente o aumento de temperatura intra-câmara pulpar durante o clareamento em consultório ativado com diferentes fontes de luz com e sem gel clareador. Foi selecionado 1 incisivo central superior humano, seccionado na porção radicular 3 mm abaixo da junção cemento-esmalte. O canal radicular foi alargado para permitir a introdução do sensor do termômetro dentro da câmara pulpar. A câmara pulpar foi preenchida com uma pasta térmica (C.N.P.J. 52.891. 405/0001-60, Implastec Electroquímica, Votorantim, SP), a fim de permitir a transferência de calor das paredes dentárias para o sensor de um termômetro digital com termopar tipo K (MT- 401A) durante o clareamento. A porção radicular do dente foi submersa em água a 37º C elevando a câmara pulpar a mesma temperatura. Um agente clareador fotossensível à base de peróxido de hidrogênio a 35% (Lase Peroxide DMC Equipamentos) foi utilizado. Para a ativação do gel foram empregados quatro aparelhos com diferentes fontes de luz: luz halógena (Spectrum Dentsply); luz híbrida à base de LED e Laser Diodo (Ultra Blue IV DMC Equipamentos); LED (Smart Lite PS Dentsply) e LED verde (D Light Green - Kondortech). As ativações foram feitas de acordo com as especificações do fabricante. com seis aplicações para cada grupo. Os resultados foram submetidos a ANOVA a dois critérios e teste de Tukey (p 0,05). Os grupos estudados e as medias do aumento da temperatura foram: D - Light Green sem gel (37ºC) A, D - Light Green com gel (37,17ºC) A, Smart Lite sem gel (39,17ºC) C, Smart Lite com gel (40ºC) D, Ultra Blue IV sem laser sem gel (38ºC) B, Ultra Blue IV sem laser com gel (39,17ºC) C, Ultra Blue IV com laser sem gel (38, 17ºC) B, Ultra Blue IV com laser com gel (39,33ºC) C, Spectrum sem gel (39,17ºC) C e Spectrum com gel (40,83ºC) E. Todas as lâmpadas apresentaram aumento da temperatura intracâmara pulpar, com exceção do D - Green Light, sem atingir a temperatura crítica de 5,5ºC. A fonte de luz halógena com gel apresentou o maior aumento de temperatura. / The purpose of this In Vitro study was to measure the intrapulpal temperature rise induced by various light sources and a bleaching gel. The root portion of an intact human maxillary central incisor was sectioned with a diamond disk 3 mm below the cement enamel junction. The apical foramen of the root was enlarged and remaining pulp tissue was removed. The empty pulp chamber was filled with a heat sink compound and a thin K-type thermocouple was introduced into the pulp chamber. The root surface of the tooth was partially submerged in a water bath during the testing procedure at 37°C elevating the pulp chamber at the same temperature. A 35% hydrogen peroxide bleaching gel (Lase Peroxide - DMC Equipamentos) containing heat enhanced colorants was applied to the vestibular tooth surface. Light units used were a conventional tungsten quartz halogen (Spectrum Dentsply), a LED/Laser device (Ultra Blue IV DMC Equipamentos), a high intensity LED (Smart Lite PS Dentsply) and a green LED light (D Light Green - Kondortech). A pilot study and a statistical analysis were made to determine the number of application needed. Six applications were made for each system and gel combination. Differences between the starting temperature and final temperature reading were taken and the calculated temperature changes were averaged to determine the mean value in temperature rise. Temperature rise values were compared using two-way analysis of variance (ANOVA) at a preset alfa of 0.05. Temperature rise varied significantly depending on the type of light used and in presence or absent of bleaching gel. The conventional tungsten quartz halogen lamp with bleaching gel induced significantly higher temperature increases than any other curing unit (3,83°C). The green light-emitting diode unit without gel produced no temperature changes. Almost as a rule, the presence of bleaching gel resulted in a significant intrapulpal temperature increase (approximately 1ºC) over that reached using no gel. However, light bleaching systems thus increase intrapulpal temperature, all the procedures used in this study were below the critical level of 5,5ºC.

A demanda de largura de banda exigida pelos usuários de redes de acesso vem aumentando rapidamente e a rede óptica passiva baseada em multiplexação por divisão de comprimento de onda (WDM-PON) tem se destacado como a tecnologia capaz de suprir essa demanda. Dessa forma, este trabalho conduz, inicialmente, uma comparação entre uma rede WDM-PON ideal e uma rede TDM-PON, discutindo também aspectos de segurança desta última, bem como estratégias de migração entre estes dois esquemas. Devido ao custo elevado da WDM-PON em seu esquema original, investigou-se em seguida as principais arquiteturas alternativas relatadas na literatura, em busca de maior viabilidade de implementação. Com base nesse estudo, fez-se então uma análise mais profunda sobre topologias recentes derivadas da RITENET, referenciadas na literatura como arquiteturas baseadas em fontes ópticas centralizadas (CLS). Tais configurações são baseadas no travamento de diodos lasers Fabry-Pérot através da injeção do sinal de ASE de um EDFA e foram estudadas por meio de simulações computacionais empregando o software OptiSystem 8.0. / The demand for bandwidth by access networks users has increased rapidly and the Wavelength Division Multiplexing - Passive Optical Network (WDM-PON) has been pointed out as the technology capable of meeting this demand. In this framework, this work initially carries out a comparison between an ideal WDM-PON network and a TDM-PON network, also discussing TDM-PON security issues as well as migration strategies from TDM-PON to WDM-PON configurations. Next, taking into account the high implementation cost of the WDM-PON original scheme, we investigated alternative topologies available in the literature. Based on this study, we performed a more in-depth analysis regarding recently proposed topologies, derived from the RITENET, which are refered at the literature as centralized light sources (CLS) based architectures. Such networks are based on the locking of Fabry-Pérot lasers diodes through the injection of the ASE signal from an EDFA and were studied by using the software OptiSystem 8.0.

Este projeto teve como finalidade construir uma fonte de luz baseada em lâmpadas halógenas que apresentasse características técnicas adequadas para aplicações em fotobiologia e fotomedicina, versátil e comercialmente viável. Foram analisadas as características de diferentes lâmpadas halógenas e realizados os experimentos com duas lâmpadas escolhidas, das quais utilizamos a lâmpada de menor divergência luminosa. Foi analisado também o material do corpo da fonte, com relação a características de aquecimento e peso, sendo escolhido um corpo de alumínio produzido industrialmente. Foram avaliadas as características ópticas das lentes, sendo escolhidas as lentes de vidro utilizadas em retroprojetores. Foram analisados os materiais e a construção de filtros térmicos para diminuir o aquecimento do objeto sob irradiação, sendo que escolhemos construir um filtro térmico próprio, que utiliza a água como absorvedor de calor. Medimos e avaliamos as características: espectrais, térmicas, a potência radiante (irradiância) e sua distribuição espacial de três protótipos, onde cada um recebeu modificações de modo a torná-los mais adequados para aplicações na fotoquimeoterapia. Foram também realizados testes preliminares de fotocitotoxicidade do protótipo final com o composto fotossensibilizador de nome comercial Photogem® aplicado em células tumorais de adenocarcinoma de colo retal humano (HT29), cujo resultado foi a ativação do composto fotossensibilizador e indução da morte celular. / The aim of this work was to produce a light source based in halogen lamps. This source should have appropriated technical characteristic for application in photobiology and photomedicine, it has easy operation and be commercially viable. The characteristics of different halogen lamps were evaluated and the lamp of smaller luminous divergence was chosen. We also have evaluated the material of the source holder, especially heating characteristics and weight; finally we chose an aluminum holder. Then, the lenses optical characteristics were studied, and we decided that the glass lenses used in projectors were the best. The materials and the construction of thermal filters were evaluated in order to reduce the heating of the object under irradiation, and we preferred to construct a thermal filter, that uses water as an heat absorber. The spectral and thermal characteristics, the radiant power (irradiance) and its space distribution of three prototypes were measured and evaluated, each one received modifications to become more appropriated to applications in photochemotherapy. We also made preliminaries tests of photocytotoxicity and the final prototype was used with the photosensitizer (Photogem®) in human colon carcinoma cell lines HT-29, resulting in the photosensitizer activation, that induced cellular death.

The theoretical part is focused on lights, notions and calculations in the area of light technology, basic lightning sources and lamps. This work is also about the principle of lightning measuring. The main aim of the work is design of a new artificial lightning system in a High school agriculture in Prerov. At first, the control measuring of existing lightning was done which is mentioned in this work. From the results of control measuring is clear, that existing lighting system in classroom does not suit requirements, which are mentioned in the valid technical norm. Design of a new lightning system meets the requirements in all of the rooms in the building of school. Design of lightning system was done in two variants. The first variant uses lamps with fluorescent tube light sources. The second variant uses lamps with LED light sources. Also is here evaluated financial difficulty of possible installation and comparation of each variants with respect energetic difficulty.

This thesis is focused on comparison of parameters of light sources (halogen, xenon, LED) installed in Skoda Octavia 3rd generation. The opening part solves analysis of the current state of lighting technology and its impact on traffic safety. The next part is focused on general parameters of light, construction of light sources, optical systems and adaptation of the human eye to various light conditions, especially contrast. The practical part is focused on comparing the contrast values of individual light sources in relation to the dark and lightly dressed pedestrian in the area without artificial lighting.

This thesis describes and documents the design and construction of a light source which is tunable and has the ability to mimic the spectral output of the sun in the photosynthetic active radiation range (400 - 700 nm). To adjust the spectral output at different wavelengths different types of LEDs were chosen and combined. This thesis describes the design, construction, testing, and suggestions for further improvements to this light source. The light source is comprised of 900 LEDs with 26 different peak wavelengths within the photosynthetically active radiation range. The light source is made tunable through the use of a control system utilizing pulse width modulation. This unique light source will allow studies to be performed to understand spectral influences on microalgae and lipid production as well as other photosynthetic organisms.

No description available.

Extreme ultraviolet lithography(EUVL) is being developed worldwide as the next generation technology to be inserted in ~ 2009 for the mass production of IC chips with feature sizes <35 nm. One major challenge to its implementation is the development of a 13.5 nm EUV source of radiation that meets the requirements of current roadmap designs of the source of illumination in commercial EUVL scanners. The light source must be debris-free, in a free-space environment with the imaging EUV optics that must provide sufficient, narrow spectral band EUV power to print 100 wafers/hr. To meet this need, extensive studies on emission from a laser plasma source utilizing tin-doped droplet target was conducted. Presented in this work, are the many optical techniques such as spectroscopy, radiometry, and imaging, that were employed to characterize and optimize emission from the laser plasma source State of the art EUV spectrographs were employed to observe the source's spectrum under various laser irradiation conditions. Comparing the experimental spectra to those from theory, has allowed the determination of the Sn ion stages responsible for emitting into the useful EUV bandwidth. Experimental results were compared to spectral simulations obtained using Collisional-Radiative Equilibrium (CRE) model, as well. Moreover, extensive measurements surveying source emission from 2 nm to 30 nm, which is the region of the electromagnetic spectrum defined as EUV, was accomplished. Absolutely calibrated metrology was employed with the Flying Circus instrument from which the source's conversion efficiency (CE)--from laser to the useful EUV energy--was characterized under various laser irradiation conditions. Hydrodynamic simulations of the plasma expansion together with the CRE model predicted the condition at which optimum conversion could be attained. The condition was demonstrated experimentally, with the highest CE to be slightly above 2%, which is the highest value among all EUV source contenders. In addition to laser intensity, the CE was found to depend on the laser wavelength. For better understanding, this observation is compared to results from simulations. Through a novel approach in imaging, the size of the plasma was characterized by recording images of the plasma within a narrow band, around 13.5 nm. The size, approximately 100 ìm, is safely within the etendue limit set by the optical elements in the EUV scanner. Finally, the notion of irradiating the target with multiple laser beams was explored for the possibility of improving the source's conversion efficiency.

Aims. We consider the polarization arising from scattering in an envelope illuminated by a central anisotropic source. This work extends the theory introduced in a previous paper (Al-Malki et al. 1999) in which scattering polarization from a spherically symmetric envelope illuminated by an anisotropic point source was considered. Here we generalize to account for the more realistic expectation of a non-spherical envelope shape. Methods. Spherical harmonics are used to describe both the light source anisotropy and the envelope density distribution functions of the scattering particles. This framework demonstrates how the net resultant polarization arises from a superposition of three basic “shape” functions: the distribution of source illumination, the distribution of envelope scatterers, and the phase function for dipole scattering. Results. Specific expressions for the Stokes parameters and scattered flux are derived for the case of an ellipsoidal light source inside an ellipsoidal envelope, with principal axes that are generally not aligned. Two illustrative examples are considered: (a) axisymmetric mass loss from a rapidly rotating star, such as may apply to some Luminous Blue Variables, and (b) a Roche-lobe filling star in a binary system with a circumstellar envelope. Conclusions. As a general conclusion, the combination of source anisotropy with distorted scattering envelopes leads to more complex polarimetric behavior such that the source characteristics should be carefully considered when interpreting polarimetric data