Dielectric Materials
Mostrando 1-12 de 86 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. Cold sintering and electric characterization of ZnO-BaTiO3 composites
Abstract The sintering is an essential step in the processing of ceramics materials. A number of researchers have reported new techniques for sintering. However, in general, the process still demands high temperatures. This paper reports the results of the cold sintering of ZnO-BaTiO3 composites. The microstructural, structural, and electric properties of th
Cerâmica. Publicado em: 2021-03
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3. Characterization of the Dielectric Properties of the Tommy Atkins Mango
Abstract This paper presents the characterization of dielectric properties (dielectric permittivity and dielectric loss factor) of Tommy Atkins mango (Mangifera indica L), a fruit produced in several regions of Brazil, of great economic importance. The fruits were characterized according to their maturation index, by probe method, and identified by the yello
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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4. Design of Three-Layer Antireflection Coating for High Reflection Index Lead Chalcogenide
Antireflection coatings (ARC), not only reduce the reflection of the incident radiation but also protect the surface from environmental degradations. In present study, three- layer design was theoretically calculated and experimentally realized on the surface of lead chalcogenide, which had high refractive characteristics. First the theoretical designs of th
Mat. Res.. Publicado em: 11/11/2019
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5. Materials from renewable resources: new properties and functions
Abstract: Sustainable production requires increasing use of raw materials from renewable sources, processed under mild conditions with minimal effluent production. These requirements are satisfied by using materials derived from biomass, in synergy with food and energy production. The possibilities of biomass are continuously enlarged by new findings, as in
An. Acad. Bras. Ciênc.. Publicado em: 21/10/2019
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6. An Amorphous Silicon Photo TFT with Si3N4/Al2O3 or HfO2 Double Layered Insulator for Digital Imaging Applications
Abstract This paper focuses on amorphous silicon photo thin-film transistors with double layered insulator using Si3N4/Al2O3 or HfO2 as candidates for the succession of Si3N4 as a traditional insulator in the fabrication of hydrogenated amorphous silicon thin-film transistors. Whether for industry or for research, there is a need to investigate the use of th
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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7. 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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8. Production of Nanometric Bi4Ti3O 12 Powders: from Synthesis to Optical and Dielectric Properties
This paper aims to evaluate the synthesis and annealing parameters for production of nanometric Bi4Ti3O12 and its properties. The powders were obtained through the solution combustion route and the impacts of annealing temperature on the materials’ physicochemical features as well as their optical and electrical properties were investigated. Thus, the prep
Mat. Res.. Publicado em: 16/07/2018
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9. Piezoelectricity from Elastic and Dielectric Measurements on Unpoled Ferroelectrics
A method is described to assess the piezoelectric response of ferroelectric materials from the temperature dependence of the elastic moduli and dielectric constant of unpoled samples. The limits and advantages over the traditional methods on poled samples are discussed. A quantitative check is made by comparing the piezoelectric softening measured below the
Mat. Res.. Publicado em: 07/06/2018
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10. Analytical Approach for Making Multilayer and Inhomogeneous Structures Invisible Based on Mantle Cloak
Abstract We investigate an analytical approach based on transmission line model to design mantle cloak for multilayer and/or inhomogeneous dielectric objects. Our proposed model is verified with different numerical results. The results matched well with each other. Also, the required impedance for making an inhomogeneous material invisible is calculated anal
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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11. Synthesis and Characterization of Non-Linear Optical Crystal of Manganese Mercury Thiocyanate Glycol Monomethyl Ether
The design and synthesis of organic nonlinear optical (NLO) crystals are a promising area of current research in materials science. Organic materials are found to possess better non linear optical properties when compared to inorganic materials. Recently, there has been a widespread interest in the metal-organic coordination compounds, which are a combinatio
Mat. Res.. Publicado em: 30/11/2017
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12. 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