X Band
Mostrando 13-24 de 676 artigos, teses e dissertações.
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13. Começa a Temporada de Frio nos Trópicos. A Crioablação da Fibrilação Atrial no Brasil
Resumo Matriz semicondutora de ZnO, dopada com Eu nas concentrações de 0,05 e 0,10 mols, foi sintetizada por reação de combustão utilizando nitrato de zinco, nitrato de európio e ureia como combustível. No intuito de analisar o efeito da concentração de európio e da sinterização na estrutura, band gap, propriedades magnéticas e morfológicas do
Arq. Bras. Cardiol.. Publicado em: 2020-09
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14. Análise das propriedades estruturais, morfológicas e magnéticas do semicondutor magnético diluído ZnO:Eu obtido via reação de combustão
Resumo Matriz semicondutora de ZnO, dopada com Eu nas concentrações de 0,05 e 0,10 mols, foi sintetizada por reação de combustão utilizando nitrato de zinco, nitrato de európio e ureia como combustível. No intuito de analisar o efeito da concentração de európio e da sinterização na estrutura, band gap, propriedades magnéticas e morfológicas do
Cerâmica. Publicado em: 2020-09
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15. Synthesis of ZnO Nanoparticles by the Sol-Gel Protein Route: A Viable and Efficient Method for Photocatalytic Degradation of Methylene Blue and Ibuprofen
The photocatalytic degradation of methylene blue dye and ibuprofen drug was studied in the presence of zinc oxide, synthetized by the protein sol-gel route. The catalyst, calcined at 1000 ºC, presented a tendentious morphology to filaments characteristic of ZnO crystalline, characterized by X-ray diffraction (XRD) and confirmed by the presence of Zn energy
J. Braz. Chem. Soc.. Publicado em: 2020-08
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16. Does Pigment Incorporation into Regular Composite Resins for Posterior Buildups Alter Their Bond Strength?
Resumo Levantes de mordida posterior são dispositivos para o tratamento ortodôntico confeccionados com resinas compostas ou materiais ionoméricos. Cuidado com a remoção destes se faz necessário para proteção da superfície dentária; para tanto, materiais pigmentados são preferidos por proporcionar melhor visualização. Este estudo propõe uma téc
Braz. Dent. J.. Publicado em: 2020-08
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17. Classificando cédulas brasileiras (R$) usando análise de imagem por smartphone
A new method to identify the authenticity of Brazilian banknotes (R$) is proposed using digital image analysis by a smartphone application, Photometrix®, associated with chemometric tools. Authentic banknotes (n = 4) obtained in local bank and falsified (n = 12) by the author himself by means of three printers (laser-Deskjet®, wax-Color Qube® and inkjet-D
Quím. Nova. Publicado em: 2020-04
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18. Mutual Coupling Reduction in Phased Array Antennas Applying High-Impedance Surface at X Band
Abstract This paper presents a microstrip phased array using High Impedance Surface - Electromagnetic Bandgap (HIS-EBG) in order to minimize the effects of mutual coupling among the antenna elements. Each element of the array is fed by a coaxial cable allowing the beam steering by controlling the signal of the input port of each element. This phased array op
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-03
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19. Cation Vacancies in NiFe2O4 During Heat Treatments at High Temperatures: Structural, Morphological and Magnetic Characterization
Nickel ferrite (NiFe2O4) was synthesized by mixing stoichiometric amounts of α-Fe2O3 and NiO using mechanical milling and heat treatments at high temperatures. The physical characterization of the samples was carried out using X-ray diffraction, infrared and Raman spectroscopies, Mössbauer spectrometry, magnetization measurements, scanning electron microsc
Mat. Res.. Publicado em: 20/12/2019
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20. Nanoparticles of Ni1-x Znx Fe2 O4 used as Microwave Absorbers in the X-band
Ferrites nanoparticles of Ni1-xZnxFe2O4 ferrites with x varying between 0 and 1, in steps of 0.2, were obtained by solution combustion synthesis (SCS) and dispersed in oil paint at the concentrations of 10, 20, 30 and 40% by ferrite weight of ferrite, with the aim of producing electromagnetic wave absorbing composites, in the X band (8-12 GHz). The ferrite p
Mat. Res.. Publicado em: 21/10/2019
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21. Frequency Selective Surface Properties of Microwave New Absorbing Porous Carbon Materials Embedded in Epoxy Resin
In this manuscript, the electromagnetic wave absorption properties of sustainable porous carbon composites were evaluated over the X-band frequency range (8.2 - 12.4 GHz). The porous carbon material was made from the byproduct of cellulose production and was used as additive on the development of radar absorbing material (RAM) composites. These porous carbon
Mat. Res.. Publicado em: 21/10/2019
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22. Modification of the Crystalline Structure of ZnO Nanoparticles Embedded Within a SiO2 Matrix due to Thermal Stress Effects
Self-assembled nanocrystals of ZnO were embedded within a SiO2 matrix by a sequential deposit using reactive R.F. sputtering. The ZnO nanoparticles (NP’s) were obtained by depositing a very thin layer (~20 nm) of Zn on the bottom of the valleys of a first SiO2 rough surface and then covered by another SiO2 layer at 500 ºC. The stress produced, due to the
Mat. Res.. Publicado em: 23/09/2019
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23. Estudio de las propiedades, estructurales, morfológicas y ópticas de nanopartículas de Cr2O3 sintetizadas por procesos de combustión de un solo paso y diferentes combustibles
ABSTRACT This research presents a novel one–step solution combustion synthesis to obtain nano-structured Cr2O3 from chrome nitrate solution and one fuel such as aspartic acid (Asp) or Lysine (Lys), or Autor Restrihydroxymethylaminomethane (Tris) or ethylenediaminetetraacetic acid (Edta). Once obtained, the ashes were calcined at 500°C. The powders were ch
Matéria (Rio J.). Publicado em: 16/09/2019
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24. Simulation and Design of a Bandpass Filter Based on Substrate Integrated E-Plane Waveguide
Abstract This paper presents a bandpass filter based on a substrate integrated E-plane waveguide (SIEW) structure for wireless applications, at X-band. The SIEW geometry allows the development of new horizontally polarized filter topologies, unlike filter structures based on substrate integrated waveguide (SIW), which present vertical polarization (perpendic
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 12/09/2019