M K Ratio
Mostrando 1-12 de 692 artigos, teses e dissertações.
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1. A Wideband and Wide Axial Ratio Bandwidth Circularly Polarized Antenna Loaded with Circular Ring Slot
Abstract The presented model for wideband circularly polarized microstrip antenna is an improved version of the previous models which is widely applicable to satellite, microwave relay and radar. The designed circularly polarized antenna having overall volume of 20× 20 × 1.6 mm3 actively works at the impedance bandwidth of 9000 MHz (4.0–12.9 GHz) having
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Pressed roofing tile based on cementitious material and basalt powder: Technological and toxicological characterization
Abstract This study aims to develop a pressed concrete roofing tile from powder technology containing basalt powder in substitution of fine sand (aggregate) for application in building covers. Specimens were submitted to technological and toxicological characterization. Hence, pressed specimens based on cement and basalt powder were analyzed. In the bending
REM - International Engineering Journal. Publicado em: 2022
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3. A Compact Dual-Band Self-Diplexing MIMO Patch Antenna for ISM and X-Band Communications
Abstract A compact, dual-band, and self-diplexing MIMO patch antenna with a shared aperture is presented for Industrial scientific medical (ISM) band and X-band communications. The structure consists of two orthogonal feed lines and a rectangular slot in a square patch. The size of the FR4 substrate is 50 × 50 × 1.6 mm3. The designed structure operates at
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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4. Microbial activity and studies on excavated megalithic micaceous potsherds from Peninsular India
Abstract The abundantly available mica flakes were added in raw materials to manufacture pottery in Central Peninsular India during the early Iron Age (700-300 BCE) for storage and glittering. The micaceous potsherds from the excavated megalithic site of Nagpur were studied for their composition, manufacturing techniques, microstructural features, microbial
Cerâmica. Publicado em: 2021-06
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5. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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6. Passively Q-Switched Pulses Generation from Erbium-Doped Fiber Laser Using Lutetium Oxide as Saturable Absorber
Abstract In this paper, a configuration of a passive Q-switched Erbium-doped fiber laser (EDFL) using a Lutetium Oxide (Lu2O3) thin film as a saturable absorber (SA) is experimentally implemented to generate high pulse energy with a high signal to noise ratio. A stable Q-switched pulse train is initiated at the input pump power of 30.442mW, and a maximum pul
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
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7. Uma proposta experimental para o estudo de oscilações acopladas usando um simulador de propagação de ondas mecânicas em meios sólidos
Resumo Neste artigo, apresentamos inicialmente um aparato, construído com materiais de fácil acesso, que pode ser empregado no estudo da lei de Hooke utilizando-se anéis de garrafa PET. Nesta fase da experimentação, esperamos que o professor reconheça junto aos seus estudantes que um anel mais largo possui constante elástica maior do que outro mais es
Rev. Bras. Ensino Fís.. Publicado em: 10/01/2020
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8. Layered Double Hydroxides with the Composition Mn/Al-SO4-A (A = Li, Na, K; Mn:Al ca. 1:1) as Cation Exchangers
Hydrated Mn/Al-SO4-A (A = Li, Na or K) layered double hydroxides with M2+:M3+ molar ratio close to 1:1 were synthesized by co-precipitation with increasing pH. All phases presented solvated alkali metals and sulfate as intercalated species. In the exchange reactions, when sulfate solutions of alkali metals were used, sodium could be partially replaced by pot
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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9. Chemosensor Development of Cu2+ Recognition Using 1,5-Diphenylthiocarbazone: Optimization, COSMO-RS and DFT Studies
The sensitive and selective chemosensor for copper(II) ions (Cu2+) was successfully optimized using the 1,5-diphenylthiocarbazone (DPT) compound. The result showed that dimethyl sulfoxide (DMSO) in a 9:1 (DMSO:water) ratio at a pH of 3 was the optimum medium for DPT to act as chemosensor of Cu2+ recognition. The DPT chemosensor did not encounter any interfer
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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10. Saline water on the leaf mineral composition of noni under organic fertilization
RESUMO A salinidade é um dos principais problemas agrícolas enfrentados, podendo influenciar negativamente o desenvolvimento vegetal. Porém, estudos têm demonstrado que em ambientes protegidos e sob aplicação de adubos orgânicos, os efeitos deletérios são amenizados. Nesse contexto, objetivou-se avaliar os efeitos da salinidade da água de irrigaç�
Rev. bras. eng. agríc. ambient.. Publicado em: 12/08/2019
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11. COMPARISON BETWEEN EXPERIMENTAL AND SIMULATED RESULTS OF BIODIESEL PRODUCTION BY REACTIVE DISTILLATION AND ENERGETIC ASSESSMENT
ABSTRACT Biodiesel appears to be a likely substitute to conventional diesel. However, the main challenge has been the creation of a competitive advantage for the biodiesel production process in terms of innovation and efficiency. The reactive distillation technique for biodiesel production is possibly a key force to overcome this technological issue because
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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12. Local head loss caused in connections used in micro-irrigation systems
RESUMO Informações sobre perda de carga localizada em conexões utilizadas em sistemas de microirrigação são difíceis de serem encontradas na literatura. O objetivo desta pesquisa foi determinar experimentalmente as perdas de carga localizada em conexões comumente empregadas nesses sistemas e propor modelos matemáticos utilizando o teorema de Bucking
Rev. bras. eng. agríc. ambient.. Publicado em: 10/07/2019