Dielectric Constant
Mostrando 1-12 de 168 artigos, teses e dissertações.
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1. Analysis of dielectric and electrical transport properties of NdFeAsO ceramic
Abstract The iron-based ceramic NdFeAsO was synthesized by the solid-state reaction method. The tetragonal crystal structure was confirmed at room temperature through the X-ray diffraction technique. The dielectric characteristics i.e. dielectric constant (εr) and loss tangent (tanδ) of the sample were studied at a wide range of temperature and frequencies
Cerâmica. Publicado em: 2022
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2. 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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3. Ferrimagnetic to paramagnetic transition and dielectric relaxation in Ni1-xZnxFe2O4 ferrites
Abstract The spinel ferrite system Ni1-xZnxFe2O4 (x=0-0.7, Δx=0.1) was prepared by wet chemical co-precipitation method using sulfates of respective metal ions. The electrical resistivity and dielectric properties of the prepared samples have been studied as a function of temperature, frequency, and Zn content (x). The DC resistivity (ϱ) was measured in th
Cerâmica. Publicado em: 2021-06
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4. Understanding Solvent/Bixin Interactions by Raman Spectroscopy
In this work, Raman spectroscopy and density functional theory (DFT) calculations have been used in order to understand the nature of the interaction between the carotenoid bixin and organic solvents with dielectric constant varying from ca. 2 (toluene) to ca. 47 (dimethyl sulfoxide). Raman shifts registered for the main carotenoid marker band, the C=C stret
J. Braz. Chem. Soc.. Publicado em: 2020-07
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5. Dielectric and Magnetic Properties of Epoxy with Dispersed Iron Phosphate Glass Particles by Microwave Measurement
Abstract This paper investigates the dielectric properties and magnetic properties of epoxy composites with different amount of powdered iron phosphate glass (IPG) at 8.2 GHz to 12.4 GHz using microwave technique. IPG composed of 60P2O5-40Fe2O3 (mol%) was produced by conventional melt and quenching method and crushed into powder. The IPG powder was character
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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6. Project and Analysis of Quasi-Periodic PBG for Microstrip Antenna
Abstract In this work the influence of quasi-periodic distributions of air holes with 6, 12 and 6-fold modified symmetries, applied to the substrate of a rectangular microstrip patch antenna are analyzed. To validate the study, parameters such as S11 parameter, bandwidth, total gain, radiation pattern and electric field were investigated through computationa
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-06
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7. Phase and microstructural analysis of NdTi0.8M0.2O3.4 (M = Al, Ga) microwave ceramics
ABSTRACT In this paper, we report the characterization of NdTi0.8M0.2O3.4 (M = Ga, Al) ceramics prepared via mixed oxide solid state sintering route. X-ray diffraction analysis of the samples revealed the formation of single phase for NdTi0.8Ga0.2O3.4 sample while secondary phase was formed in the case of NdTi0.8Al0.2O3.4. Microstructural analysis of the sam
Matéria (Rio J.). Publicado em: 25/11/2019
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8. A origem clássica da força do oscilador
Resumo O conceito de força do oscilador é útil em várias áreas da química e da física, tais como emissão e absorção de radiação, constante dielétrica, índice de refração e colisões inelásticas entre partículas carregadas e átomos e moléculas. Na maioria dos livros didáticos, o conceito de força de oscilador é introduzido de forma ad h
Rev. Bras. Ensino Fís.. Publicado em: 07/10/2019
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9. Silver nanoparticles incorporated PVC films: evaluation of structural, thermal, dielectric and catalytic properties
Abstract In this work, silver nanoparticle – polyvinylchloride (SNC-PVC) composites were synthesized by loading 2.5% to 10.0% silver ions to PVC using simple solution casting technique. Material properties including dielectric, thermal stability were discussed in some detail. Incorporation of silver nanoparticles (SNPs) in the PVC matrix was confirmed by U
Polímeros. Publicado em: 03/10/2019
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10. Quantitative evaluation of soil ion content using an imaginary part model of soil dielectric constant
ABSTRACT: An imaginary part model of soil dielectric constant for predicting the soil salinity status was developed based on a series of relations between dielectric imaginary part and soil bulk conductivity, soil bulk conductivity and soil solution electrical conductivity, and soil solution electrical conductivity and ion contents in soil using pot trials w
Sci. agric. (Piracicaba, Braz.). Publicado em: 2019-07
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11. Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization
Resumo Hexaferritas de estrôncio com adição de Y3+ com composição química SrYxFe12-xO19 (x= 0,0, 0,5, 1,0, 1,5) foram sintetizadas com sucesso pelo método sol-gel com autocombustão. Os estudos estruturais e morfológicos das amostras preparadas foram investigados usando a técnica de difração de raios X, espectroscopia de energia dispersiva, micros
Cerâmica. Publicado em: 06/06/2019
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12. Pseudopotential Study of CdTe Quantum Dots: Electronic and Optical Properties
The present contribution reports on the electronic and optical properties of zinc-blende CdTe quantum dots using a pseudopotential approach. Our findings showed that the predicted nano-structured direct band gap is significantly increased relative to the bulk one. For a nanocrystal diameter in the range 1.2-5 nm, the refractive index and dielectric constant
Mat. Res.. Publicado em: 30/05/2019