Electromagnetic Fields
Mostrando 1-12 de 147 artigos, teses e dissertações.
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1. Electromagnetic Transients in Multiconductor Transmission Lines
Abstract The theory of multiconductor transmission lines is based on the principle of superposition. According to this principle, any electric or magnetic field can be represented as the sum of individual electric or magnetic fields. This theory is used to analyze and design electrical systems involving multiple conductors. In this work, the procedures for a
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Meshless Methods for Computation of Overhead Transmission Lines Electromagnetic Fields
Abstract The meshless element-free Galerkin method (EFGM) is used to solve partial differential equations responsible for obtaining the electromagnetic fields generated by a transmission line. For this purpose, a 2D model based in a real transmission line is constructed and simulated. The results obtained by EFGM have good accuracy and they are compared agai
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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3. USE OF GROUND PENETRATING RADAR TO STUDY SPATIAL VARIABILITY AND SOIL STRATIGRAPHY
ABSTRACT Ground Penetrating Radar (GPR) is a geophysical method that uses electromagnetic waves to study subsurface structure in different fields such as geology, agriculture and civil engineering. The wave penetration in the soil is strongly controlled by the electrical conductivity of soil components such as clay, organic matter, and water. In this study,
Eng. Agríc.. Publicado em: 19/06/2019
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4. Investigation of Thermal Effects in Coaxial Probe Method and Dielectric Characterization of Glycerol up to 140°C
Abstract Dielectric properties of a material are of paramount importance in many areas of knowledge. All scientific fields that deal with the interaction of electromagnetic radiation with matter demand this information. Consequently, suitable methods for obtaining accurate dielectric data are required. In the microwave community, the dielectric metrology wit
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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5. Precision production environments for sugarcane fields
ABSTRACT: Sugarcane (saccharum spp.) in Brazil is managed on the basis of “production environments”. These “production environments” are used for many purposes, such as variety allocation, application of fertilizers and definition of the planting and harvesting periods. A quality classification is essential to ensure high economic returns. However, t
Sci. agric. (Piracicaba, Braz.). Publicado em: 2019-02
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6. Compensation technique for environmental and light source power variations applied in a polymer optical fiber curvature sensor for wearable devices
Abstract Introduction Polymer optical fibers (POF) are lightweight, present high elastic strain limits, fracture toughness, flexibility in bend, and are not influenced by electromagnetic fields. These characteristics enable the application of POF as curvature sensor and can overcome the limitations of the conventional technologies, especially for wearable a
Res. Biomed. Eng.. Publicado em: 05/03/2018
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7. A Hybrid Approach for Assessments of Equivalent Emission Sources and Electromagnetic Environments
Abstract This paper presents a method for equivalent emission source determination by application of LLAs (Large Loop Antennas). A review of different types of LLAs is carried out and their characteristics regarding emission source evaluation are emphasized. A hybrid technic is applied for obtaining the electric fields based on previous measurement of magnet
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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8. A Numerical Mode-Matching Method Based on Multiple-Knot Cubic B-Splines Applied to the Analysis of Well-Logging Tools
Abstract The numerical mode-matching (NMM) technique is a very efficient approach to analyze well-logging tools used for hydrocarbon exploration. This problem is typically modeled as a cylindrically layered medium (subterranean formation) including both horizontal and vertical stratifications. In this paper, we present a new NMM formulation based on the use
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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9. Design of Ground Penetrating Radar Antenna for Detecting Soil Contamination at L-band Frequencies
Abstract Maintenance of oil pipelines is an issue of great concern for oil companies. Soil contamination is caused by oil leaks from underground pipelines. Ground penetrating radar (GPR) is a rapid and relatively inexpensive technique used for locating and characterizing soil contaminated sites without producing fractures and causing further migration of con
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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10. Electromagnetism as a world view: implications for the teaching of energy
There are considerable differences in the ways mechanics and electromagnetism conceptualize energy. In the former, energy is defined in terms of force and work in a process-like reasoning that remits us to the ”past” of a given body or system. Moreover, in the mechanical framework energy is ascribed to matter, i.e., one speaks of the energy of a system o
Rev. Bras. Ensino Fís.. Publicado em: 22/06/2017
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11. Metallurgical Characterization of API X65 Steel Joint Welded by MIG Welding Process with Axial Magnetic Field
In this work, API X-65 pipeline steel non-conventionally heat treated, to enhance its mechanical resistance, was welded using the Metal Inert Gas (MIG) process with and without the application of low intensity axial magnetic fields (6 mT). Microstructural and mechanical characterization of the welds revealed that the use of the magnetic field during welding
Mat. Res.. Publicado em: 23/03/2017
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12. Pseudo-Analytical Modeling of Tilted-Coil Antennas in Anisotropic Geophysical Formations
Abstract In this paper we present an efficient mode-matching technique to analyze tilted-coil antennas in anisotropic geophysical formations. In this problem, a number of coil antennas with arbitrary relative tilt angle with respect to the symmetry axis are used to radiate electromagnetic fields in a cylindrically layered medium comprised of a metallic mandr
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-03