• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.5
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• pp.264-267
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• 2004

Recently the pulsed power systems have been widely used in many fields such as E/P(Electrostatic Precipitator), DeNOx/DeSOx power systems, ozone generators and power sources of the laser beam. In this paper, we studied various electrical characteristics for arc suppression of line-to-line electrodes in air and removal of the metaloxide using our pulsed power system. To obtain high efficiency of the pulsed power system, we repeatedly experimented and tested their characteristics. by adjusting electrode length of the load. As a result, when the value of the electrode length and pulse repetition rate were changed at the load, the value of the arc voltage changed at the electrode load. In conclusion, we controlled arc voltage of the load by ,changing electrode length and pulse repetition rate. Also. we stydied removal area of the metaloxide using area discharge according to pulse repetition rate.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.91-96
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• 2010

SCM440 steels were nitrided using pulsed dc plasma combined with inductively coupled plasma (ICP) generated by 13.56 MHz rf power in order to enhance case hardening depth. The case hardening depth was increased with rf power. The effective case-depth with ICP at 900 watt was as 1.6 times as that nitrided without ICP. The hardening depth was also increased up to 1.45 times. The compound layers formed on top surface were dense and thin when pulsed dc plasma was combined with ICP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.82-85
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• 2000

We introduce pulsed $CO_2$ laser power supply excited by half-wave rectified 60Hz AC discharge some advantage of cost and size compared to a typical pulsed power supply. AC frequency is adjusted from 10Hz to 60Hz to control laser output. In this laser, a low voltage open loop control for high voltage AC discharge circuits is employed to avoid the HV sampling or switching. The control is achieved by using a ZCS circuit and a PIC one-chip microprocessor that control the gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to a high leakage inductance. The maximum laser output was obtained about 20W at the condition of total pressure, 18Torr and pulse repetition rate,60Hz.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1910-1912
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• 1996

This paper presents the results of laboratory experimentals to remove $SO_2$ and $NO_x$ by a pulsed corona discharge in the wire-plate reactor. A rotating spark gap switch was used to generate the pulse by chewing the dc high voltage. Repetition frequency of the pulse was 60Hz and rising time of 50ns. The photo pictures of positive streamer corona taken by ICCD camera, pulse voltage and current were measured using a digital oscilloscope. Simultaneous effects of $C_{2}H_{4}$ injection and heterogeneous chemical reactions on nonthermal plasma process to remove $SO_2$ and $NO_x$ from flue gas were investigated in the present study

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.208-211
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• 2003

The dielectric carbon nitride thin films were deposited onto Si(100) using a pulsed laser ablation of pure graphite target combined with a high voltage discharge plasma in nitrogen gas atmosphere. We can be calculated dielectric constant, ${\varepsilon}_s$, with a capacitance Sobering bridge method. We reported to investigate the influence of the laser ablation of graphite target and DC high voltage source for the plasma. The properties of the deposited carbon nitride thin films were influenced by the high voltage source during the film growth. Deposition rate of carbon nitride films were found to increase drastically with the increase of high voltage source. Infrared absorption clearly shows the existence of C=N bonds and $C{\equiv}N$ bonds. The carbon nitride thin films were observed crystalline phase, as confirmed by x-ray diffraction data.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2010-2012
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• 1999

The product of electrons by Pulsed Corona Discharge leads to produce radicals which work on NO, and NO is finally removed. Energy efficiency for NO removal was improved with increasing peak voltage rather than with increasing pulse frequency. The rate of energy transfer increased with decreasing value of $C_p$( Pulse - Forming Capacitance 2.15, 1.06, 0.55, 0.36, 0.1[nF]. When the value of $C_p$ reached to 0.36 [nF], the energy efficiency for NO removal was maximized. And good agreement was obtained between chemical kinetic calculations and the experimental results.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.10a
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• pp.27-32
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• 2003

The phenomenon of electrical explosion of conductors is considered in the context of the changes in the energy and structural states of the metal at the stages of energy delivery and relaxation of the primary products of EEC. It is shown that these changes are related to the forced interaction of an intense energy flux with matter and to the subsequent spontaneous relaxation processes. The characteristics of nano-sized metal powders are also discussed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.7
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• pp.310-313
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• 2003

The purpose of this paper is to evaluate the effects of pre-formed space charges by DC stress on partial discharge(PD) characteristics in XLPE. We have suggested a modified pulsed electro-acoustic(PEA) method and successfully measured both space charge distribution and current simultaneously. It has been demonstrated that the PD patterns are strongly influenced by the pre-formed space charge distributions, which are hardly disappeared up to AC 8㎸ in electrode configuration including air gap between XLPE layer and electrode. From the results, it could be said that the pre-formed space charges by DC stress can play harmful and dangerous roles in insulating system under AC operating voltages because of the field distortion and localization due to the pre-formed space charge.

• Proceedings of the Korean Vacuum Society Conference
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• 2005.08a
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• pp.154-154
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• 2005

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.939-944
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• 2001

For the application of simultaneous $DeSO_{2}\;&\;DeNO_{x}$ equipment using non-thermal plasma process to the industrial and power plants, the many types of plasma device and process were studied. The e-beam and pulsed plasma corona discharge process are outstanding for the study to apply commercial large-scale plant from among these. In this paper, non-thermal plasma of technical trends and the characteristics of system developed by Doosan heavy industries & construction Co., Ltd. are explained. We have researched pulsed plasma corona discharge process since 1994. At the basis of reasonable results for the pilot plant, we constructed the demonstration plant at a domestic coal-fired power plant in 1999, as the previous step for commercial use. In near future, enough information about designs and costs of commercial-size system will be obtained.