Optical Detectors
Mostrando 1-12 de 28 artigos, teses e dissertações.
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1. An Overview of Research into Low Internal Friction Optical Coatings by the Gravitational Wave Detection Community
The direct detection of gravitational waves by ground-based interferometric gravitational wave detectors in recent years has opened a new window of the universe, allowing the astrophysical observations of previously unexplored phenomena, such as the collisions of black holes and neutron stars. However, small thermodynamic fluctuations of the density of the t
Mat. Res.. Publicado em: 24/05/2018
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2. Sistema para medida simultânea de temperatura e deformação com redes de Bragg em 800 nm / Simultaneous measurement of temperature and strain using fiber Bragg gratings written at 800 nm
In recent years, fiber Bragg gratings (FBGs) have been frequently used as strain and temperature sensors. Several studies have tackled the problem of distinguishing between these two physical parameters using a dual-wavelength sensor. Although these sensors have shown good results, they have a few drawbacks, one of them being the need for two light sources w
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/11/2012
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3. Propriedades ópticas, magnéticas e estruturais de monocristais Cs2NaAlF6 dopados com cromo trivalente / Optical, magnetic and structural properties of Cs2NaAlF6 single crystals doped with trivalent chromium
This work is devoted to study the optical, magnetic and structural properties of the elpasolite crystal Cs2NaAlF6 with 0.1, 1.0, 3.0, 10.0, 30.0 and 50.0% of Cr3+ ions. The interest on this material lies on the fact that such system presents a broad, intense band in the visible and infrared regions at room temperature and therefore can be used as a tunable r
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/08/2011
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4. MODELING OF THE CARDIAC ELECTRODYNAMICS AND OF THE EFFECTS OF SPATIAL AND TIME RESOLUTION ON OPTICAL MAPS / MODELAGEM DA ELETRODINÂMICA CARDÍACA E DOS EFEITOS DA RESOLUÇÃO ESPACIAL E TEMPORAL EM MAPAS ÓPTICOS
Fluorescence studies using potentiometric dyes to optically measure the action potential of cardiac cells constitute an important tool to better understand the electrophysiology of the heart. However, in many experimental setups, the finite sensing area of optical detectors cannot be neglected. As a consequence, the detected fluorescence signal may effective
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/02/2011
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5. Fabricação e caracterização de sensor de pixel ativo com tecnologia NMOS de porta metalica / Fabrication and characterization of active pixel sensors using metal gate NMOS technology
Active Pixel Sensors (APS) based on a simple nMOS technology with high aspect ratio may present good sensitivity to photodetection and offer a low cost option for image sensing circuits. This work presents the layout, fabrication and characterization of photodiodes, transistors and APSs built at the Center for Semiconductor Components (CCS). All the process
Publicado em: 2009
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6. New electronic technique for temperature measurement with 0.5 mº C resolution using optical fiber bragg gratings / Nova tecnica eletronica para medida de temperatura com resolução de 0,5 mºC usando sensores de fibras opticas com grades de Bragg
Por serem eletricamente passivos e imunes à interferência eletromagnética, os sensores a fibra óptica estão se tornando uma excelente escolha para o sensoreamento em várias aplicações, como aeroespacial, distribuição e geração de energia elétrica, transportes ferroviários, e equipamentos de segurança militares. Entre outras vantagens está o f
Publicado em: 2009
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7. New technique for the implementation of digital demodulation of fiber optic gyroscopes / Implementação de uma nova tecnica para demodulação digital de sinal de giroscopio a fibra optica
Gyroscopes are devices used to measure angular orientation, being extensively employed for guidance, navigation and stabilization. Among the many types of gyroscopes, IFOG (Interferometer Fiber Optic Gyroscope), based on Sagnac effect, is the most interesting solution due to its high sensitivity, resolution, reliability, small size and EMI immunity. The pres
Publicado em: 2009
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8. Medidas da temperatura e densidade eletronica utilizando a unicidade do tempo de confinamento de particulas no Tokamak NOVA-UNICAMP / Electronic density and temperature measurements using the particle confinement time iniqueness in the NOVA-Tokamak
In this work, we have made simultaneous measurements of three hydrogen emission lines on our tokamak. From the measurements of absolute brightness of the Ha , H b e Hg lines an using data from Johnson an Hinnov table, was possible to determine electronic ensities an temperatures during the tokamak ischarges. For this,we have used, an refined, a technique dev
Publicado em: 2009
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9. CaracterizaÃÃo de um fÃmur sintÃtico empregando o mÃtodo dos elementos finitos e validaÃÃo por extensometria Ãtica / Characterization of a sintetic femur with the employment of the finite element method and validation by optical extensometry
This work makes use of sensors based on fiber Bragg gratings, for the validation of a numerical model on the finite elements method of a synthetic femur, produced by SawbonesÂ. The numerical model was developed from a numerical model already used at the University of Aveiro. For validation, was developed a system for setting and implementation of load steps
Publicado em: 2009
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10. Gamma-induced modification on optical band gap of CR-39 SSNTD
Effect of gamma irradiation on optical absorption of nuclear track detectors like CR-39 was studied in different absorbed doses using ultraviolet-visible (UV-VIS) spectroscopy. The existence of the peaks, their shifting and broadening as a result of gamma irradiation has been discussed. The width of the tail of localized states in the band gap (Eu) was evalu
Brazilian Journal of Physics. Publicado em: 2008-12
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11. Abordaje de la enseñanza de aspectos importantes de la física moderna a traves del uso de un laser de xenon multi-ionico pulsado
This work intendes to present a pulsed multi-ionic Xe laser to perform demonstrations, lab experiments or begin research works in topics of modern physics, atomic spectroscopy and gaseous lasers. It can be used also in the graduate and post-graduate teaching. In addition, the use of all the instruments that compose the equipment allows to make contact with h
Revista Brasileira de Ensino de Física. Publicado em: 2007
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12. Development of dissolved oxygen sensors using electrochemical and optic methods for real time monitoring of water quality. / Desenvolvimento de sensores de oxigênio dissolvido utilizando métodos eletroquímicos e ópticos para monitoramento em tempo real da qualidade da água.
This work aims the development of a dissolved oxygen (DO) sensor using thick film technology, which has low cost of production and keeps sensors durability and precision acceptable for their use in the monitoring of water sources. This development also includes the complete electronic circuits for autonomous monitoring. Using the principles of oxygen electro
Publicado em: 2007