Magnetic Flux
Mostrando 13-24 de 135 artigos, teses e dissertações.
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13. Detection and analysis of rotor faults in induction motors by the measurement of the stray magnetic flux
This paper presents measured data and electromagnetic FEM field calculations as techniques for detecting and analyzing eccentricity in three-phase induction motors. Also it presents experimental results for detecting broken bars in induction motor rotors. A search-coil is used as magnetic field sensor to measure the stray magnetic flux outside the motor. It
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2012-06
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14. Reconhecimento de PadrÃes AtravÃs de AnÃlises EstatÃsticas e Fractais Aplicadas a Dados de Ensaios NÃo-Destrutivos / Pattern Recognition by Statistical Fluctuation and Fractal Analyses Applied to Nondestructive Testing Data
In this work a procedure is studied for pattern classification related to different types of data, namely: (1) signals obtained from ultrasonic testing ( pulse-echo technique) and magnetic signals obtained from BarkhÃusen noise in samples of ferritic-pearlitic carbon steel tubes which, due to temperature effects, have shown microstructural changes as conseq
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2011
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15. Magnetic effect on free convection in a non-darcy porous medium saturated with doubly stratified power-law fluid
Natural convection heat and mass transfer along a vertical plate embedded in a doubly stratified power-law fluid saturated non-Darcy porous medium with uniform heat and mass flux is presented. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically. The eff
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-03
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16. Analytical method to predict the static performance of a planar actuator
An analytical method for predicting the three-dimensional (3-D) magnetic flux density distribution in the air gap produced by permanent magnets of an electromagnetic planar actuator, was developed. The analytical 3-D model was validated by means of a finite-element model and by measurements. It allowed the understanding of the behavior of the flux density in
Publicado em: 2011
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17. Application of neodymuim-iron-boron permanent magnets on the assembling of a novel planar actuator
This paper depicts a new planar actuator, with novel structure and construction features. It includes a slotless stationary plane armature and a mover with two permanent magnets. By using NdFeB permanent magnets with high-energy product, it became possible to develop a planar motor with a novel topology. The planar actuator develops movement over a plane sur
Publicado em: 2011
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18. Evaluation of the normal force of a planar actuator
This paper describes a method to compute the normal force that acts on the mover of an electromagnetic planar actuator. The method is based on the Maxwell Stress Tensor and depends on the resulting magnetic field. The actuator has a mover with two permanent magnets and a ferromagnetic stator covered by two orthogonal armature coils. The mover is hold by a su
Publicado em: 2011
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19. Design and test of HTS coils for resistive fault current limiter
This paper presents the design, manufacturing and test results of HTS coils for single-phase resistive current limiters using two different Bi-2223/Ag tapes. Two coils were separately wound on cylindrical G-10 tubes with helical path. One of the coil was wound in a bifilar conductor arrangement aiming at reducing the self-inductance. The maximum flux density
Publicado em: 2011
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20. Numerical model of electromagnetic stirring for continuos casting billets
Thispaperintroducesanumericalmodelofanelectromagnetic rotary stirrer based on the finite-element model.Such stirrers are used to improve the quality of continuously cast steel, particularly billets and blooms. The method determines the magnetic flux density profile and compares it to experimental measurements. In addition, it calculates the Lorentz force fie
Publicado em: 2011
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21. Obtenção e caracterização de supercondutores de Bi2212 texturizados com introdução de centros artificiais de aprisionamento / Production and characterization of textured Bi2212 superconductors with introduction of artificial pinning centers.
The present work analyzed the texturing conditions of Ag/Bi2212 samples (Bi2Sr2CaCu2O8+δ) in the form of bulks and of tapes, verifying the influence of heat treatment, atmosphere, silver addition and addition of zirconia or calcium zirconate. The additions of zirconia or calcium zirconate, with particles of submicron or nanometric (below 200nm) dimensio
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/09/2010
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22. Estudo de microestruturas magnéticas por microscopia de força magnética
A manipulação e o controle das propriedades magnéticas de materiais com pequenas dimensões tem atraído interesse crescente nos últimos anos. Para sistemas magnéticos micrométricos ou submicrométricos, diferentes configurações magnéticas são energeticamente acessíveis. Vórtices magnéticos merecem destaque entre essas configurações e figuram
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/06/2010
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23. Measurement of the plasma boundary shift and approximation of the magnetic surfaces on the IR-T1 Tokamak
In this research we measured the plasma boundary shift using array of magnetic pick- up coils on the IR- T1 tokamak. Also we approximated the magnetic surfaces by an equilibrium calculation. Firstly, four magnetic probes were designed, constructed, and installed on outer surface of the IR- T1 tokamak chamber and then plasma boundary displacement measured fro
Brazilian Journal of Physics. Publicado em: 2010-09
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24. CONSTRUCTION OF AN COMPACT SQUID MAGNETOMETER FOR CHARACTERIZATION OF THE MAGNETIC NANOPARTICLES USED IN BIOLOGICAL ASSAYS / CONSTRUÇÃO DE UM MAGNETÔMETRO SQUID COMPACTO PARA CARACTERIZAÇÃO DE NANOPARTÍCULAS MAGNÉTICAS UTILIZADAS EM ENSAIOS BIOLÓGICOS
The immunoassay is an important tool in clinical diagnostics and in fundamental research. Magnetic nanoparticles, bound with antibodies, have been applied increasingly for various immunoassays with the purpose of separation and quantification of antigens. We developed a system based on bulk SQUIDs for detecting the field generated from remanent magnetization
Publicado em: 2010