• Title/Summary/Keyword: magneto-current

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Measurement and Analysis of the Flux Profiles of the Coated Conductors using Magneto-optical Image and Scanning Hall Probe (Coated conductor에서 magneto-optical image와 scanning hall probe를 이용한 flux profile의 측정 및 분석)

  • Lee, H.Y.;Kwak, K.S.;Rhyee, J.K.;Yoo, J.;Youm, D.
    • Progress in Superconductivity
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    • v.11 no.2
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    • pp.128-134
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    • 2010
  • The magnetic flux profiles in SmBCO and YBCO coated conductors(CC) in the presence of the external field were comparatively investigated by magneto-optic image and scanning hall probe measurements. The current distributions calculated by using the inversion method from measured field profiles show that the decrease of current densities near the edges of SmBCO CC is more significant than those of YBCO CC. Through the comparison of the numerical analysis based on Kim's critical state model and the Brandt and Indenbom's solution, we found that this feature is related to their different field dependant properties of the critical current densities.

Deformation in a nonlocal magneto-thermoelastic solid with hall current due to normal force

  • Lata, Parveen;Singh, Sukhveer
    • Geomechanics and Engineering
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    • v.22 no.2
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    • pp.109-117
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    • 2020
  • The present article is concerned about the study of disturbances in a homogeneous nonlocal magneto-thermoelastic medium under the combined effects of hall current, rotation and two temperatures. The model under assumption has been subjected to normal force. Laplace and Fourier transform have been used for finding the solution to the field equations. The analytical expressions for conductive temperature, stress components, normal current density, transverse current density and displacement components have been obtained in the physical domain using a numerical inversion technique. The effects of hall current and nonlocal parameter on resulting quantities have been depicted graphically. Some particular cases have also been figured out from the current work. The results can be very important for the researchers working in the field of magneto-thermoelastic materials, nonlocal thermoelasticity, geophysics etc.

A Study on Direct Current Measurement Using Magneto-Optical LMF Method (자기장학 누설자속법을 응용한 직류전류계측법에 관한 연구)

  • Lee, Jin-Yi
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.6
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    • pp.566-572
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    • 2004
  • It is necessary to measure the direct current with a non-contact methodology for the liquid or gas phase, as welt as the conducting metals. This paper described a theoretical consideration and experimental verification for a non-contact quantitative direct current measurement system using the Faraday effect and magnetic flux leakage. The leakage of magnetic flux occurs around a gap when a ferromagnetic core including the discontinuous gap is magnetized. Two large anisotropic domains in a magneto-optical film are occurred by the vertical component of leaked magnetic flux and the domain walls are paralleled to the center of the gap. Here, the symmetrical arrangement of domains are deflected when a vertical magnetic field is applied to the magneto-optical film. The domain wall of the magneto-optical film are relocated when a measuring current passes through the ferromagnetic core. Therefore, a direct current passing through the core can be determined quantitatively by the measurement of moving distance of the domain wall.

Relative Magneto-current of Magnetic Tunnel Transistor with Amorphous n-type Si Film

  • Lee, Sang-Suk;Lee, Jin-Yong;Hwang, Do-Guwn
    • Journal of Magnetics
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    • v.9 no.1
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    • pp.23-26
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    • 2004
  • A magneto-current (MC) was investigated for magnetic tunnel transistor (MTT) with amorphous n-type Si film. A relative MC (more than 49.6%) was observed at an emitter-base bias voltage ($V_{EB}$) of 0.65 V at room temperature. Above a $V_{EB}$ of 0.70 V, however, a rapid decrease in MC was observed in the amorphous Si-based MTT. The collector current increasing and transfer ratio as emitter-base voltage were mainly due to the rapid creation electrons of conduction band states in the Si collector. This approach would make integration in various components and systems easier than a MTT grown on a semiconductor wafer.

The Effect of Orientation of Magneto-responsible Particles on the Transmissibility of Magneto-rheological Elastomer (자기장 응답 입자의 배향이 자기유변 탄성체의 전달성에 미치는 영향)

  • Lee, Joo-Hwan;Chung, Kyung-Ho;Yoon, Ji-Hyun;Oh, Jae-Eung;Kim, Min-Soo;Yang, Kyung-Mo;Lee, Seong-Hoon
    • Elastomers and Composites
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    • v.46 no.4
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    • pp.311-317
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    • 2011
  • The neodymium magnet inserted mold was proposed to orient magneto-responsible particles efficiently. The anisotropic magneto-rheological elastomer(MRE) was prepared using the new mold and the optimum amounts of the particles was 30 vol.%. As the orientation of particles was increased, the tensile strength of MRE was decreased, while the hardness of MRE was increased. It was found that the MRE containing 30 vol.% of magneto-responsible particles showed the maximum magneto-rheological effect. The ratio of shear modulus shift was 59% at the input current of 3 A. The transmissibility of MRE was decreased with increasing the input current and loading amounts of magneto-responsible particles. Therefore, the damping property of MRE could be improved by preparing the anisotropic MRE.

Propagation of plane wave in transversely isotropic magneto-thermoelastic material with multi-dual-phase lag and two temperature

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.5
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    • pp.411-432
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    • 2020
  • This research is devoted to the study of plane wave propagation in homogeneous transversely isotropic (HTI) magneto-thermoelastic rotating medium with combined effect of Hall current and two temperature due to multi-dual-phase lag heat transfer. It is analysed that, for 2-D assumed model, three types of coupled longitudinal waves (quasi-longitudinal, quasi-transverse and quasi-thermal) are present. The wave characteristics like phase velocity, specific loss, attenuation coefficients, energy ratios, penetration depths and amplitude ratios of transmitted and reflected waves are computed numerically and illustrated graphically and compared for different theories of thermoelasticity. Some particular cases are also derived from this research.

Identification of Negative Stiffness Effects in Magneto-Rheological Fluid based Squeeze Film Damper (자기유변유체를 이용한 스퀴즈 필름 댐퍼에서의 부강성 효과 규명)

  • 김근주;김정훈;이종원
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.739-744
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    • 2001
  • In order to investigate the stability of magneto-rheological fluid based squeeze film damper (MR-SFD), its negative stiffness effect, which arises from magnetization of MR-SFD, is identified theoretically and experimentally. The analytical model of MR-SFD includes the magnetic circuit as well as the displacement stiffness associated with the squeeze mode of MRF. Extensive experiments are carried out to measure the magnetic attraction forces generated in the MR-SFD, with the excitation frequency and the eccentricity of the journal varied, which are controlled by an active magnetic bearing. The simulation and experimental results are found to be in good agreement. It is concluded that the negative stiffness effect dominates only in the low frequency region because its effect diminishes in the high frequency region due to the eddy-current loss.

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Effect of hall current in Transversely Isotropic magneto thermoelastic rotating medium with fractional order heat transfer due to normal force

  • Lata, Parveen;Kaur, Iqbal
    • Advances in materials Research
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    • v.7 no.3
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    • pp.203-220
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    • 2018
  • This investigation is focused on the study of effect of hall current in transversely isotropic magneto thermoelastic homogeneous medium with fractional order heat transfer and rotation. As an application the bounding surface is subjected to normal force. The research becomes more interesting due to interaction of Hall current with the effect of rotation as it has found various applications. Laplace and Fourier transform is used for solving field equations. The analytical expressions of temperature, displacement components, stress components and current density components are computed in the transformed domain. The effects of hall current and fractional order parameter at different values are represented graphically.