Optical Systems
Mostrando 1-12 de 392 artigos, teses e dissertações.
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1. MGF Methods for Fixed and Gain Saturated Optically Preamplified FSO Links Impaired by Misalignments and Atmospheric Turbulence
Abstract The Gaussian approximation is commonly used to evaluate the performance of free space optical communication systems. However, other performance evaluation methods such as the saddle point approximation, Chernoff bound and the modified Chernoff bound have also been used. This paper investigates the performance of fixed and gain saturated optically pr
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. 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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3. Low-Overhead Low-Complexity Carrier Phase Recovery Technique for Coherent Multi-Band OFDM-Based Superchannel Systems Enabled by Optical Frequency Combs
Abstract In this paper, we have designed a low-overhead low-complexity carrier phase tracking scheme for OFDM-based superchannel transmission system enabled by optical frequency combs. In this scheme, taking advantage of the broadband phase coherence provided by optical frequency combs among the OFDM-bands, the carrier phase retrieved from pilot-subcarriers
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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4. Reactivity of sera from dogs living in a leishmaniasis-endemic area to the COOH-terminal region of cysteine proteinase B
ABSTRACT Cysteine proteinases are well-known virulence factors of Leishmania spp. with demonstrated actions in both experimental mouse infection and human infection. However, studies on these enzymes in canine leishmaniasis are scarce. Here, we show, for the first time, the reactivity of sera from dogs living in an endemic area to a recombinant protein from
Braz J Infect Dis. Publicado em: 2020-06
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5. ONE-POT DIASTEREOSELECTIVE SYNTHESIS OF CHIRAL TRICYCLIC L-CYSTEINE AND D-PENICILLAMINE DERIVATIVES: A LABORATORY EXPERIMENT
A one-pot diastereoselective synthesis of thiazolidine-ring fused systems derived from enantiomerically pure amino acids, L-cysteine or D-penicillamine, and achiral succindialdehyde is described as an experiment to be carried out by upper-division undergraduate students in a laboratory classroom. Reactions were performed under mild conditions, the products w
Quím. Nova. Publicado em: 2020-01
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6. Size and shape-controlled nanomaterials based on modified polyol and thermal decomposition approaches. A brief review.
Abstract: Since its inception in 2007, the Colloidal Materials Group, one of the research groups in nanotechnology of the Institute of Chemistry of São Carlos (IQSC) at University of São Paulo (USP) carries out studies related to the development of syntheses methods of nanoparticles and multifunctional nanostructured systems. Our works search new synthesis
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
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7. Uso de retinógrafo portátil como ferramenta no rastreamento de retinopatia diabética
Resumo Objetivo: Determinar a concordância do retinógrafo portátil Pictor Plus, na ausência de midríase, com a retinografia digital e avaliar a sua acurácia como método de rastreio da retinopatia diabética (RD). Métodos: Estudo transversal, mascarado para o observador, avaliando 100 olhos de 51 pacientes diabéticos. Foram realizadas retinografia
Rev. bras.oftalmol.. Publicado em: 04/11/2019
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8. Doxycycline release and antibacterial activity from PMMA/PEO electrospun fiber mats
Abstract Objective: To investigate the use of polymethyl methacrylate (PMMA) electrospun fiber mats containing different amounts of polyethylene oxide (PEO) as a doxycycline delivery system and to test antibacterial activity against an oral pathogen. Methodology: PMMA powders or PEO (mol wt 200 Kd) (10,20,30% w/w/) were dissolved in N, N-dimethylformamide
J. Appl. Oral Sci.. Publicado em: 07/10/2019
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9. Desenvolvimento e caracterização de membranas de quitosana / Cissus Verticillata (L.) Nicolson & C.E. Jarvis
RESUMO Os polímeros, devido às suas diversas aplicações e funcionalidades, estão entre os excipientes mais utilizados para a obtenção de formas farmacêuticas, ganhando destaque a quitosana. O objetivo deste trabalho foi desenvolver e avaliar comparativamente membranas de quitosana com diferentes concentrações da espécie vegetal Cissus verticillata
Matéria (Rio J.). Publicado em: 16/09/2019
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10. Study and Optimization of Raman Amplifiers in Tellurite-Based Optical Fibers for Wide-Band Telecommunication Systems
Abstract Here we present a numerical analysis and the optimization of a multi-pump discrete Raman amplification system based on the use of a Tellurite optical fiber as the gain media. By using previously reported optimization techniques we were able to exploit the high Raman gain of Tellurite optical fibers and its multipeak spectrum to achieve amplification
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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11. Mejora de la resistencia al desgaste abrasivo de un revestimiento Fe-Cr-Mn-C mediante la adición de V
ABSTRACT The aim of this work is to increase the abrasive wear resistance of a coating, applied on plates of AISI 1020 carbon steel, using tubular coated electrodes with the Fe-Cr-Mn-C alloy system. In order to achieve this increase, V was added to the alloy system. The resulting coating were studied using optical microscopy (MO), X-ray diffraction and micro
Matéria (Rio J.). Publicado em: 20/05/2019
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12. Determinação de metais em peixes e camarão-rosa (Farfantepenaeus paulensis) do estuário da Lagoa dos Patos (Pelotas-RS, Brasil) por MIP OES
Resumo No presente trabalho, a técnica de espectrometria de emissão óptica com plasma induzido por micro-ondas foi empregada para determinar as concentrações de Al, Cd, Cu, Hg, Mg, Sb e Zn em amostras de peixes (bagre, tainha, traíra, pintado e corvina) e de Al, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sb, Ti e Zn em amostras de camarão-rosa (Farfante
Braz. J. Food Technol.. Publicado em: 25/02/2019