Excitation Systems
Mostrando 1-12 de 132 artigos, teses e dissertações.
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1. Single Port Multimode Reconfigurable UWB-NB Antenna for Cognitive Radio Applications
Abstract In this paper, a compact, single port, multimode reconfigurable UWB-NB antenna with a novel feeding network is presented. The proposed antenna consists of a pentagonal-shaped monopole radiator, a beveled-shaped partial defected ground plane with a rectangular slot, and a reconfigurable bypass feeding network. The antenna realizes a wideband frequenc
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. An Overview of the Photocatalytic H2 Evolution by Semiconductor-Based Materials for Nonspecialists
The solar-to-chemical energy conversion is promising to tackle sustainability challenges toward a global future. The production of H2 from sunlight represents an attractive alternative to the use of carboniferous fossil fuels to meet our energy demands. In this context, the water splitting reaction photocatalyzed by semiconductors that can be excited under v
J. Braz. Chem. Soc.. Publicado em: 2020-02
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3. 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
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4. On the Nonlinear Transient Analysis of Planar Steel Frames with Semi-Rigid Connections: From Fundamentals to Algorithms and Numerical Studies
Abstract This paper presents the fundamentals for prediction of a more realistic behavior of planar steel frames with semi-rigid connections under dynamic loading. The majority of the research in this area concentrates on the nonlinear static analysis of frames with semi-rigid connections. Indeed, few studies have contributed to the nonlinear dynamic and vi
Lat. Am. j. solids struct.. Publicado em: 03/05/2018
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5. Influence of the Protonatable Site in the Photo-Induced Proton-Coupled Electron Transfer between Rhenium(I) Polypyridyl Complexes and Hydroquinone
In the present work the influence of the distance of the protonatable site of different ancillary ligands to the metal center on the luminescence quenching of ReI polypyridyl complexes by hydroquinone are evaluated by means of experimental and theoretical studies. In these systems, it is expected the occurrence of proton-coupled electron transfer (PCET) reac
J. Braz. Chem. Soc.. Publicado em: 2017-09
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6. Pattern Identification on the Nonlinear Radial Motion of an Oscillating Spherical Bubble Using Neural Networks
Abstract The main goal of this article is to study the oscillatory motion of a spherical gas bubble immersed in a Newtonian liquid subjected to a harmonic pressure excitation. We use the classical Rayleigh-Plesset equation to study the radial motion of the bubble undergoing a forcing acoustic pressure field. The second order nonlinear ordinary differential e
Lat. Am. j. solids struct.. Publicado em: 2016-12
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7. Comparison of In-Flight Measured and Computed Aeroelastic Damping: Modal Identification Procedures and Modeling Approaches
ABSTRACT The Operational Modal Analysis technique is a methodology very often applied for the identification of dynamic systems when the input signal is unknown. The applied methodology is based on a technique to estimate the Frequency Response Functions and extract the modal parameters using only the structural dynamic response data, without assuming the kn
J. Aerosp. Technol. Manag.. Publicado em: 2016-06
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8. Dielectric Behavior of Alginate-Based Hydrogel Containing Neomycin-Loaded Lipid Nanovesicles under Influence of Electrical Potentials
Dielectric characterization has been applied as a convenient tool for evaluation of transport and polarization mechanisms in soft materials. In this work, we have explored the study of charge transport mechanisms in alginate hydrogel containing neomycin-loaded liposomes. For comparison, drug release kinetic was evaluated by using UV-Vis spectrophotometry and
J. Braz. Chem. Soc.. Publicado em: 2016-01
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9. Molecular dynamic study of the jet noise about the micro-scale tube
This paper studies the two-dimensional micro-scale molecular simulations of the jet flow using Lagrange discrete systems and adopting Andresen flexible constraint mechanism. At the effects of different excitation conditions and boundary conditions, the low Mach number flow field and sound field are obtained, and characteristic results are given. At the jet f
Matéria (Rio J.). Publicado em: 2014-12
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10. Corrosion resistance of 2024 aluminum alloy coated with plasma deposited a-C:H:Si:O films
AA 2024 aluminum alloy is widely employed in aeronautic and automobilist industries. Its hardness and low density are attractive properties for such industrial areas. However, since it contains copper, it undergoes severe corrosion in aggressive media as saline or low Earth orbit environments. In this work, it was investigated the properties of films deposit
Mat. Res.. Publicado em: 2014-12
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11. Simulação da dinâmica do estado excitado em semicondutores orgânicos / Simulation of the excited state dynamics in organic semiconductors
In the present work, the Monte Carlo method and the direct numerical integration of the Master Equation were employed to simulate the excitation spectral diffusion process in light emitting polymeric systems. The methodology employed a competition among the internal intra-molecular relaxation, the inter-molecular incoherent energy transfer via Förster mecha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2012
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12. Estudo da relação entre propriedades de compósitos de fricção aplicados a sistemas de freio a disco e a propensão à ocorrência de Squeal Noise
Automotive brake systems are very often susceptible to generate high frequency noise as a result of a self excited vibration. This phenomenon is generically nominated brake squeal noise and is the subject of many studies which intend to identify and describe its exciting mechanism and to propose counter measures to avoid its occurrence. One key subject yet t
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012