• Journal of Magnetics
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• v.18 no.3
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• pp.331-338
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• 2013

We present a few significant advances in methods and concepts of magnetic measurements, aimed both at providing novel routes in the characterization of hard and soft magnetic materials and at improving our basic knowledge of the magnetization process. We discuss, in particular, investigation methods and experimental arrangements that have been developed in recent times for: 1) Hysteresis loop determination in extra-hard magnets by means of Pulsed Field Magnetometry; 2) Broadband observation of domain wall dynamics by highspeed stroboscopical Kerr techniques; 3) Entropy measurements in magnetocaloric materials by calorimetry in magnetic field. While pertaining to somewhat independent fields of investigation, all these measuring techniques have in common a solid approach to the underlying physical phenomenology and have a potential for further developments.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.328-333
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• 2006

All the plants on earth live under an electric and magnetic field because the earth is a magnet and there is an electric field between the charged cloud and the ground. It has been reported that electromagnetic fields influence both the activation of ions and polarization of dipoles in living cells of seeds and plants, though the mechanism of these actions is still poorly understood. In this paper, the effects of the electric and magnetic fields and exposure times to the germination of several vegetable seeds and its early growth have been investigated experimentally to find out the feasibility of a plant factory for mass production of clean and unpolluted vegetables. The germination rate and the growth rate of some seeds under the fields exposed were analysed and compared with those of unexposed ones. It is found that the germination rate and its early growth rate of exposed seeds under the fields were accelerated about 1.1-1.4 and 1.7-2.2 times in maximum compared with those of unexposed ones. But, however, an inhibitory effect on germination and plant early growth were shown in the case of the higher electric and magnetic fields.

• Smart Structures and Systems
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• v.29 no.5
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• pp.705-714
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• 2022

In this paper, the effect of magnetic field on the vibration behavior of a Magnetorheological elastomer (MRE) sandwich MEMS actuated by electrostatic actuation with conductive skins are examined within the multiple scales (MMS) perturbation method. Magnetorheological smart materials have been widely used in vibration control of various systems due to their mechanical properties change under the influence of different magnetic fields. To investigate the vibrational behavior of the movable electrode, the Euler-Bernoulli beam theory, as well as Hamilton's principle is used to derive the equations and the related boundary conditions governing the dynamic behavior of the system are applied. The results of this study show that by placing the Magnetorheological elastomer core in the movable electrode and applying different magnetic fields on it, its natural vibrational frequency can be affected so that by increasing the applied magnetic field, the system's natural frequency increases. Also, the effect of various factors such as the electric potential difference between two electrodes, changes in the thickness of the core and the skins, electrode length, the distance between two electrodes and also change in vibration modes of the system on natural frequencies have been investigated.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.49-54
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• 2017

In this paper, we propose magnetic field wireless power transfer antenna using Ferrite. It is possible to transfer magnetic field wireless power without independent ground by using characteristic of ferrite in the point that conventional magnetic field wireless power transfer was possible with independent grounding. Ferrite has a shielding effect of magnetic field and reduces leakage power, thereby improving transfer efficiency. We propose an antenna for magnetic field wireless power transfer using ferrite and confirmed that it is transmitted by 5W magnetic field wireless power through experiments. The wireless power transfer proposed in this paper can be applied variously to the Internet of things by using the magnetic field wireless power transfer through the metal.

• Progress in Superconductivity and Cryogenics
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• v.21 no.4
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• pp.48-52
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• 2019

Recently, many studies have been reported on the magnetoresistance and Hall effect of REBCO thin films and bulk. The voltage interferes quench detection of high-temperature superconducting magnet and generates leakage current in no insulation high-temperature superconducting coil. Therefore, in this paper, experiments on magnetoresistance and Hall effect of commercial YBCO and GdBCO tapes have been carried out. As a result, anomalous voltages expected for the magnetoresistance and Hall effect of REBCO tapes were observed and analyzed. In addition, the voltage characteristics of REBCO have been identified, and the Hall coefficient are calculated for use in high magnetic field magnet applications.

• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.589-598
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• 2023

Magnetic curves are the trajectories of charged particals which are influenced by magnetic fields and they satisfy the Lorentz equation. It is important to find relationships between magnetic curves and other special curves. This paper is a study of magnetic curves and this kind of relationships. We give the relationship between β-magnetic curves and Mannheim, Bertrand, involute-evolute curves and we give some geometric properties about them. Then, we study this subject for γ-magnetic curves. Finally, we give an evaluation of what we did.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.12-12
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• 2010

The hall probe measurement system was used to measure the critical current distribution of superconducting coated conductor. The system consists of reel to reel moving apparatus, 7 array hall probe, a rotary encoder and permanent magnet. The magnetic field profile across the width of superconducting coated conductor using Bean's critical state model was calculated. The effect of various parameters of the formulas on the magnetic field distribution and the effect of shape and size of artificial defects, which were formed on the surface of SmBa2Cu3O7-d(SmBCO) coated conductor using laser marking system, on the hall probe magnetic field signal of the hall probe measurement system was investigated.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1989.10a
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• pp.9-12
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• 1989

ABSTRACT -- Recently, a method of magnetically-enhanced discharge columns is considered to increase the luminous efficacy of discharge lamps, which is based upon the face that the diffusion motion of charged particles in the discharge column strongly depends on the applied magnetic fields. This study investigates the effect of applied transverse magnetic fields on the light output of low-pressure Hg-Ar discharge. As a result, it is found that the electric field in the positive column increases according to the applied megnetic field, which causes an increase in the total light output. And this effect is much more pronounced upon the spectral line originating form the higher levels.

• Progress in Superconductivity and Cryogenics
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• v.13 no.4
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• pp.14-17
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• 2011

The evaluation of the electromechanical properties of HTS CC tapes is one of the foremost procedures to be done to ensure the applicability of superconducting wires to electric devices. A precise measurement of the stress and strain is important in deriving the mechanical properties under operating environment. Up to now, there is no standard test method yet for the electromechanical property evaluation of HTS tapes under self field and external magnetic field although there are already reports on the different devices used to evaluate these properties. Strain can be measured by adopting a strain gauge or a high resolution double extensometer. In this study, strain effect on $I_c$ in HTS CC tapes under magnetic fields was evaluated. Comparison of advantages and setback of strain measuring devices were discussed. In addition, a dual strain measurement system using both the SG and extensometer may be practical to lessen the burden in case one of the measuring devices does not work well.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.425-434
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• 2020

The present paper is concerned at investigating the effect of hydrostatic initial stress, gravity and magnetic field in fiber-reinforced thermoelastic solid, with variable thermal conductivity. The formulation of the problem applied in the context of the three-phase-lag model, Green-Naghdi theory with energy dissipation, as well as coupled theory. The exact expressions of the considered variables by using state-space approaches are obtained. Comparisons are performed in the absence and presence of the magnetic field as well as gravity. Also, a comparison was made in the three theories in the absence and presence of variable thermal conductivity as well as hydrostatic initial stress. The study finds applications in composite engineering, geology, seismology, control system and acoustics, exploration of valuable materials beneath the earth's surface.