• Journal of Information Display
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• v.4 no.1
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• pp.34-37
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• 2003

We investigate the solid phase crystallization of amorphous Si films on glass substrates under alternating magnetic field induction. The kinetics of crystallization are found to be greatly enhanced by alternating magnetic field. While complete crystallization takes heat treatment of more than 14 hours at 570$^{\circ}C$, it can be reduced by applying the megnetic field to 20 minutes. It is assumed that the enhancement of crystallization is associated with an electromotive force voltage generated by alternating magnetic field. This electric field applied in the amorphous Si may possibly be the reason for acceleration of the atomic mobility of crystallization through the modification of atomic potentials

• Journal of Magnetics
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• v.20 no.3
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• pp.290-294
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• 2015

To investigate the effects of alternating magnetic field intensity and stimulation time on the proliferation of human breast cancer cells (BT-20), we cultured the cells under a magnetic field with a saw tooth waveform of 2 kHz. The field intensities varied from 3 to 7 mT, and the stimulation time varied from 24 to 72 hours. Cell proliferation decreased dramatically to 40% during magnetic stimulation for 72 hours at 5 mT. However, the cells were not affected by a strong magnetic field of 7 mT. The p-values obtained using statistical package for social science software were below 0.05 for 5-7 mT. This means that the results have statistical significance. However, it is difficult to explain our results based on the physiology of cell membranes, which have various ionic flows at ion channels.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.124-125
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• 2001

The electro-magnetic vector equation(F=$qv{\times}B$ ; F：force, B：magnetic field, q：plus charge, v ：velocity of the charge) explains well about the rotations of electron and positron under the magnetic field[Ref.1], as in Fig.1(a). Because the electro-magnetic wave is also a motion of the alternating charge and magnetic field as in Fig.2, the force vector has all the time inwarding direction and then the wave has a rotating motion. The positron in the proton has constant charge and alternating one at the same time[Ref.2] and then the alternating charge makes the absorbing force with the alternating charge of the rotating wave ($\pi$-ray) around the nucleus[Ref.2]. (omitted)

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.35-39
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• 2004

Statistical design of experiments was successfully employed to investigate the effect of alternating magnetic field on activation of polycrystalline Si (p-Si) doped as n-type using $\textrm{PH}_3$, by full factorial design of three factors with two levels. In this design, the input variables are graphite size, alternating current, and activation time. The output parameter, sheet resistance, is analyzed in terms of the primary effects and multi-factor interactions. Notably, the three-factor interaction is calculated to be a dominant interaction. The interaction between graphite size and activation time and the main effect of current are important effects compared to the other variables and relevant interactions. Alternating magnetic flux activation is proved a significantly beneficial processing technique.

• Nuclear Engineering and Technology
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• v.34 no.5
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• pp.494-501
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• 2002

Radioactive Corrosion Products (CRUD) which are generated by the neutron activation of general corrosion products at the nuclear power plant are the major source of occupational radiation exposure. Most of the CRUD has a characteristic of showing strong ferrimagnetisms. Along with the new development and production of permanent magnet (rare earth magnet) which generates much stronger magnetic field than the conventional magnet, new type of magnetic filter that can separate CRUD efficiently and eventually reduce radiation exposure of personnel at nuclear power plant is suggested. This separator consists of inner and outer magnet assemblies, coolant channel and container surrounding the outer magnet assembly. The rotational motion of the inner and outer permanent magnet assemblies surrounding the coolant channel by driving motor system produces moving alternating magnetic fields in the coolant channel. The CRUD can be separated from the coolant by the moving alternating magnetic field. This study describes the results of preliminary experiment performed with the different flow rates of coolant and rotation velocities of magnet assemblies. This new magnetic filter shows better performance results of filtering the magnetite at coolant (water). How rates, rotating velocities of magnet assemblies and particle sizes turn out to be very important design parameters.

• Journal of Magnetics
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• v.17 no.1
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• pp.42-45
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• 2012

We have developed an alternating magnetic field stimulation system consisting of a switched-mode power supply and a digital control circuit which modulates a duty ratio to maintain a magnetic field intensity of a few mT even while the frequency increases up to 4 kHz with a controllable coil temperature below $30^{\circ}C$ in air. This duty ratio modulation and water circulation are advantageous for cell culture under ac-magnetic field stimulation by preventing the incubator from exceeding a cell-viable temperature of $37^{\circ}C$. Although the temperature of the coil when subjected to a sinusoidal voltage rapidly increased, that of our system modulated by the duty factor did not change. This is a potentially valuable method to investigate the effects of intermediate frequency magnetic field stimulation on biological entities such as cells, tissues and organs.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.589-592
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• 1998

The performance of inductively coupled plasma (ICP) is enhanced by axial magnetic field driven by alternating current Helmholtz coils in this work. Langmuir pobe is used to characterize the plasma, and the etching performance is demonstrated with phororesist stripping process. It is shown that its density and uniformity depends on the frequency of driving current to the magnetic field.

• The Journal of Korea Robotics Society
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• v.4 no.4
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• pp.320-326
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• 2009

This paper proposed a new magnetic field detection algorithm to detect metal pieces in food producing processes. This algorithm can detect mixed metal pieces by sensing magnetic field. Some metal pieces are passed through an over-current circuit to magnetize them. The magnetic field sensor can detect the change in the magnetic field on theconveyor belt caused by the flow of the metal pieces in the food product. However, such a method detects the output of signals that change their amplitude and phase according to the movement of the conveyor belt with the food product, in which the equilibrium of the positive signal that is created in the receiver coil loses its balance due to the magnetized material. This includes not only the signal elements resulting from the effect of the alternating magnetic fields of the mixed metals, but also the signal elements resulting from the effect of the alternating magnetic fields of the examined object itself.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.33-38
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• 2010

In this paper, the nature of iron loss in electrical steel during alternating field excitation is investigated more precisely. The exact definition of AC iron loss is cleared by accurately measuring the iron loss for conditions of both the sinusoidal magnetic field and sinusoidal magnetic flux density. The results of this approach to iron loss calculations in electrical steel are compared to experimentally-measured losses. In addition, an inverse hysteresis model considering eddy current loss was developed to analyze the iron loss when the input is the voltage source. With this model, the inrush current in the inductor or transformer as well as the iron loss can be calculated.

• Journal of the Korean Vacuum Society
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• v.14 no.1
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• pp.24-28
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• 2005

A typical method for obtaining poly-Si films is the solid phase crystallization(SPC) of amorphous Si. Advantages of SPC are uniformity, process quality and low cost of production. However, high process temperature and long process time prevent the employment of SPC process on thermally susceptible glass substrate. In this parer, we propose a new method that applies an alternating magnetic field during crystallization annealing in an alternating magnetic field crystallization(AMFC) system for lowering process temperature and shorter process time of SPC. When we crystallized, in the case of SPC, annealing time is 24 hours at 570℃. But in the case of AMFC, annealing time is only 20 minutes at the same temperature.