• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1705-1707
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• 1998

In this paper, a superposed discharge type ozonizer was designed and manufactured. The ozonizer is equipped with three electrodes : central electrode, internal electrode and external electrode, and it consists of two gaps. The ozone is generated by superposing silent discharge, which are respectively generated betweens two gaps. This paper describes the following two characteristics : (1) 'the characteristics of discharge with variation with output voltage of AC High Voltage source, quantity of the supplied gas and discharge voltage (2) the characteristics of ozone discharge power, temperature of the supplied gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.208-214
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• 2011

In this thesis, the partial discharge according to applied voltage and variations of cross-sectional area and length of the conductor related to general condition for using cable was measured in order to study degradation diagnosis for 2-Core cable of the PVC insulator used in industrial fields for other safety installations. Also the thermal degradation conditions under various installation circumstances of cables were studied by assuming degradation conditions with each different degradation rate (50%, 67%, 100%) such as variation in degradated temperature, thermal exposure time, normal state, partially degradated state and overall degradated state for thermal degradation diagnosis. The quantity of electric discharge (V-Q) according to applied voltage was measured for measurement of inception voltage and extinction voltage. The quantity of electric discharge and the number of electric discharge (Q-N) were measured with applied voltage kept constantly. In addition, pictures were taken using SEM (scanning electron microscope) to compare the surface of external insulator to degradated state of internal insulator according to thermal degradation temperature and also compare the surface of external insulator to degradated surface state of internal insulator according exposure time of cables to thermal stress.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.696-701
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• 2005

This paper was investigated the changes of surface properties of high-temperature-vulcanized (HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone rubber surface by oxygen plasma were accessed using Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), contact angle and Surface Roughness Tester. The results of the chemical analysis Showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx, x=$3\~4$) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized (HTV) semiconductive silicone rubber also, Surface roughness was increased with cleavage of side-chains and oxidation process, it confirmed change as the SEM. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.422-425
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• 2005

This study predicts the heat-affected zone (HAZ) after electrical discharge machining. To predict HAZ, the temperature distribution is calculated using FEM. Heat flux is calculated from electrical energy, and it can be assumed Gaussian distribution. Plasma channel expands as time goes. Copper and NAK80 are used as the workpiece material. The depth of HAZ in simulation is determined by temperature distribution. The simulation results were compared with a developed actual single discharge crater. Through investigating the cross section of simulated & actual craters, the depth of HAZ in simulation and experiment are compared. Simulation model can predict the crater shape.

• Journal of Energy Engineering
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• v.2 no.3
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• pp.300-307
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• 1993

To develop high performance nickel-iron secondary battery, the characteristics of charge-discharge reaction of iron electrode were examined by cyclic voltammetry technique, SEM and XRD analysis. The capacity of the test electrodes was determined by the constant current charge-discharge method. It was found that the temperature and concentration of electrolyte were the major determinant factors of electrode capacity, and especially the 1st discharge capacity was increased with the increase of temperature. The effect of fore forming agent on the electrode capacity was negligible. The electrode capacity was above 350 ㎃h/g(36% utility) at 0.25C discharge rate. The stability of electrode was very good, but the activation occurred slowly.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1376-1379
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• 2007

The effects of the MgO fabrication process on the properties of AC-PDPs were examined. MgO films were deposited by e-beam evaporation with various substrate temperatures and oxygen flow rates. MgO films were analyzed by XRD, CL and ellipsometer. Panel properties such as luminance, efficiency, discharge voltage and discharge delay time were measured with test panels. MgO films with higher temperature, smaller oxygen flow rate showed shorter discharge delay time. Also they showed smaller XRD peak intensity. These results revealed that the discharge delay time was strongly influenced by temperature and oxygen flow rate of the MgO fabrication process.

• Journal of the Korean Vacuum Society
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• v.5 no.1
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• pp.77-84
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• 1996

Silicon deposition by Penning discharge was carried out using a mixture of 5% $SiH_4/H_2$ and Ar gas, and the effects of the deposition conditions(gas mixing raito, substrate temperature. discharge power etc.) on the growth rate, crystallinity and morphology of the films deposited were investigated. The magnetic field(800 G) confined the plasma in the region between the two cathodes and enhanced the discharge current by a factor of a few hundreds below 1 mTorr. The magnetic field-enhanced plasma density resulted in a very large deposition rate of about 300 $\AA$/min at $SiH_4$ flow rate of 0.7 sccm and the substrate temperature of $800^{\circ}C$. Characterization of the films by Raman spectroscopy, X-ray diffraction, and scanning electron microscopy revealed that an epitaxial film with a smooth surface grows above 80$0^{\circ}C$, an amorphous film below $400^{\circ}C$, and a rough polycrystalline film at intermediate temperatures.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.10
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• pp.902-907
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• 2003

In this paper, the ITO thin film, which is considered as one of the most currently used material for the high performance transparent conducting films for the PDP cell, was made in a parallel-plate, capacitively coupled DC magnetron sputtering system. Some electrical and optical properties of ITO films were investigated and discussed on the basis of glow discharge characteristics. The optimized thin film fabricating conditions of Ar gas pressure and substrate temperature were derived from the Paschen curve and glow discharge characteristics. The maximum transmittance of 89.61 % in the visible region and optical band gap of 3.89 eV and resistivity of 1.67${\times}$10$\^$-3/ $\Omega$-cm were obtained under the conditions of 300 C of substrate temperature and 10∼15 mtorr of pressure, which corresponds nearly to that of Paschen minimum.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.4
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• pp.136-139
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• 2003

The positive column of a discharge tube filled with a mixture of mercury-xenon has a tendency to become contracted at room temperature. However, once the tube temperature is raised over 50 [$^{\circ}C$], the positive column changes from a contracted state to a diffused state. The xenon emission is stronger in the contracted positive column than in the diffused column. Alternatively, the mercury emission is more intense in the diffused positive column, and the luminance of the phosphor coating on the inner surface of the tube is higher than that in the contracted positive column. Moreover, higher luminance can be obtained by increasing the xenon pressure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.488-491
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• 2002

We report the observation of line shapes in the optogalvanic spectrum, which are different from those of absorption, for transitions origination from the $3P_2$ ($1s_5$ in Paschen notation) metastable level of argon. The OG line shapes resemble those of absorption and be used to diagnose the characteristics of the discharge plasma. The measured plasma temperatures of Ar hollow cathode discharge for several metal cathodes are about 620~780K at discharge current of 7~10mA.