Optics
Mostrando 1-12 de 455 artigos, teses e dissertações.
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1. Radially Periodic Metasurface Lenses for Magnetic Field Collimation in Resonant Wireless Power Transfer Applications
Abstract In this paper, a new procedure and topology of magnetic metasurface lens are proposed for improving the performance of Resonant Wireless Power Transfer systems. Firstly, three subwave-length unit cells are optimized in order to get negative magnetic permeability in the same frequency, each one with a different refractive index, and they are experime
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Assessment of Total Attenuation and Adaptive Scheme for Quality of Service Enhancement in Tropical Weather for Satellite Networks and 5G Applications in Nigeria
Abstract The dynamic weather condition is a major concern for optimum channel utilization in recent times, especially at higher frequencies with larger bandwidth for 5G applications. Over the years, rain-induced attenuation among the hydrometeors has been linked as the major cause of signal impairment especially at the frequency, f ≥ 10 GHz. However, when
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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3. HERMANN VON HELMHOLTZ, EWALD HERING AND COLOR VISION: A CONTROVERSY OVER STYLES OF REASONING?
Abstract During the second half of the 19th century, in the field of physiological optics, there was a strong controversy between Hermann von Helmholtz and Ewald Hering. This controversy has been usually characterized as “empiricism” vs. “nativism”. In the field of physiology of visual perception, several subjects demanded attention, among them, colo
Manuscrito. Publicado em: 2021-03
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4. Imaging evaluation of hallux valgus
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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5. GO Synthesis of Offset Dual Reflector Antennas Using Local Axis-Displaced Confocal Quadrics
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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6. Comportamento da função renal na crioablação percutânea de massa renal
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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7. Hidrodissecção modificada para biópsia guiada por tomografia computadorizada de lesões mediastinais: técnica “marshmallow”
Abstract This work investigates an alternative numerical scheme for the solution of an exact formulation based on Geometrical Optics (GO) principles to synthesize offset dual reflector antennas. The technique is suited to solve a second-order nonlinear partial differential equation of the Monge-Ampère type as a boundary value problem. An iterative algorithm
Radiol Bras. Publicado em: 2020-06
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8. Simulación de trazos de rayos de un triplete de Cooke
Abstract In this paper, we developed the theoretical model Cooke triplet in an environment that runs programs quickly; which means you can build surfaces; increasing them and solving more complex and elaborated designs. This result is compared with the optical device developed with OSLO EDU [1] software. We show how a simple code is presented as a computatio
Rev. Bras. Ensino Fís.. Publicado em: 13/01/2020
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9. Rubeosis faciei diabeticorum is not associated with oxidative stress and skin autofluorescence
Abstract Background Rubeosis faciei diabeticorum is a persistent facial erythema in patients with diabetes mellitus. The actual pathogenesis has not been studied. However, it is speculated to be a cutaneous diabetic microangiopathy. Objective Examine the correlation between the severity of facial erythema and the possible causes of microvascular diabetic c
An. Bras. Dermatol.. Publicado em: 09/12/2019
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10. Lentes de gelatina
Resumo Neste trabalho apresentamos um aparato de baixo custo, lúdico e de fácil acesso para experimentação na área de óptica geométrica. A simplicidade da montagem e a facilidade do manuseio favorecem a aplicação deste projeto, que se propõe a construir lentes esféricas com gelatina comestível. Com o auxilio de gabaritos de papel, feitos no forma
Rev. Bras. Ensino Fís.. Publicado em: 11/11/2019
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11. Uma abordagem histórica da reflexão e da refração da luz
Abstract Este trabalho apresenta uma proposta de ensino dos fenômenos da reflexão e da refração da luz a partir de uma abordagem histórica da ciência. Essa abordagem histórica é fundamentada em cinco pilares: estudos em história da óptica, a experimentação investigativa, os três momentos pedagógicos, a leitura contextualizada de fontes primári
Rev. Bras. Ensino Fís.. Publicado em: 09/09/2019
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12. Estudo das propriedades do Diodo Emissor de Luz (LED) para a determinação da constante de Planck numa maquete automatizada com o auxílio da plataforma Arduíno
Resumo No presente artigo, apresenta-se o método experimental de determinação da constante de Planck, uma das constantes físicas fundamentais, através do estudo das propriedades quânticas e ondulatórias do diodo emissor de luz (LED) numa maquete experimental automatizada, que contém um circuito eletrônico ligado a um computador utilizando o protocol
Rev. Bras. Ensino Fís.. Publicado em: 09/09/2019