Reflectivity
Mostrando 1-12 de 65 artigos, teses e dissertações.
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1. Investigate the Effect of Dielectric Properties on Microwave Absorption of Pyramidal Microwave Absorber
Abstract This paper presents an analysis of the impact of various dielectric properties material’s effects on broadband pyramidal microwave absorbers (PMA). The Computer Simulation Technology (CST) studio software simulates and analyzes the PMA over 0.7 GHz to 30 GHz frequency range. To achieve the best reflectivity performance of the PMA, different types
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Transient retinal artery occlusion after phacoemulsification under local anesthetic block
RESUMO Relatamos um caso de um paciente submetido a facectomia por facoemulsificação sob bloqueio anestésico peribulbar, sem intercorrências per-operatória, que apresentou no primeiro dia de pós-operatório baixa visual significativa. À fundoscopia observou-se palidez em aspecto de mácula em cereja. A angiofluoresceinografia não demonstrou sinais de
Rev. bras.oftalmol.. Publicado em: 12/08/2019
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3. Ultrassonografia do nervo óptico no modo A para o diagnóstico do glaucoma
Resumo Objetivos: Determinar se a medida do diâmetro horizontal ou refletividade do nervo óptico retrobulbar no modo A apresenta correlação com a relação da escavação pelo diâmetro do nervo óptico no glaucoma, considerando: a correlação das medidas, a sensibilidade e especificidade entre os métodos e qual a medida tem maior sensibilidade e espe
Rev. bras.oftalmol.. Publicado em: 2019-02
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4. Effect of the Morphology and Structure on the Microwave Absorbing Properties of Multiwalled Carbon Nanotube Filled Epoxy Resin Nanocomposites
The current research shows the effect of structural and morphological differences of multilayer carbon nanotubes (CNT) on radar absorbing materials (RAM) performance. Two CNT samples, from different manufacturers, had their morphological and structural aspects investigated by XRD, SEM and SEM-FEG analyses. CNT/epoxy resin based nanostructured composites were
Mat. Res.. Publicado em: 16/07/2018
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5. Improved Electronic Structure and Optical Performance of Bi2Te3-xSex From First-principle Calculations Within TB-mBJ Exchange Potential
Using the first-principle calculations of density functional theory within the (FP-LAPW) method, we have investigated the structural, electronic and optical properties of Bi2Te3-xSex alloys with compositions x = 0, 1, 2 and 3 of Se. The generalized gradient approximation functional of Wu and Cohen (GGA-PBE) is used to calculate ground state structural parame
Mat. Res.. Publicado em: 17/11/2017
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6. Producing BiI/BiOI Thin Films via Chemical Bath Deposition
In this paper, we tried to describe a different method for producing BiI and BiOI thin films, which is chemical bath deposition on glass substrates. Structural and optical properties of BiI and BiOI thin films were examined using X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-VIS measurements. Film thicknesses of the films were measured
Mat. Res.. Publicado em: 16/02/2016
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7. Development of paints with infrared radiation reflective properties
Abstract Large buildings situated in hot regions of the Globe need to be agreeable to their residents. Air conditioning is extensively used to make these buildings comfortable, with consequent energy consumption. Absorption of solar visible and infrared radiations are responsible for heating objects on the surface of the Earth, including hou
Polímeros. Publicado em: 2015-06
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8. Long-term stability decay of standard and regenerated Bragg gratings tailored for high temperature operation
Thermal stability of both standard and regenerated Bragg gratings written in normal and photosensitive optical fibers was accessed. An apparent spectral wavelength stabilization of common gratings with no thermal hysteresis was reached after thermal treatments. However, after a time interval of 5 months, gratings exhibited a shift in the resonance Bragg wave
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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9. Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials
Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multiwalled carbon nanotubes results in a new functional
Mat. Res.. Publicado em: 03/09/2013
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10. Reflectivity of Hybrid Microwave Absorbers Based on NiZn Ferrite and Carbon Black
Abstract: This study had as main objective to show that the adequate combination of magnetic and dielectric particles can improve the radar absorbing materials performance. For this, formulations of polyurethane resin loaded with carbon black and NiZn ferrite, with general composition MFe2O4, where M = Ni, Zn or both elements, homogenized by conventional mec
J. Aerosp. Technol. Manag.. Publicado em: 2012-09
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11. Assessing biophysical variable parameters of bean crop with hyperspectral measurements
Recently high spectral resolution sensors have been developed, which allow new and more advanced applications in agriculture. Motivated by the increasing importance of hyperspectral remote sensing data, the need for research is important to define optimal wavebands to estimate biophysical parameters of crop. The use of narrow band vegetation indices (VI) der
Scientia Agricola. Publicado em: 2012-04
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12. Trazendo à baila a voz que fomenta pesquisas em linguagem: uma análise crítica do discurso do professor-orientador através do Sistema de Transitividade / Bringing up the voice that fosters research in language: a critical discourse analysis of the adviser through the system of transitivity
The New Law of Directives and Bases of Brazilian Education (LDB 9.394/96) forecasts that higher education promotes critical, reflectivity, correlation of knowledge, but also the incentive to "research work and scientific research aiming the development of science and technology and the creation and dissemination of culture and, thus, to develop the understan
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/12/2011