• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.2
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• pp.9-14
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• 2007

Recently, in order to improve the characteristics of operating voltage, brightness, discharge time lag, luminous efficacy of ac PDP, the PDP with high Xe partial pressure has been investigated. However, the serious problems in this case is to increase the operating voltage of ac PDP. In this study, in order to meet this problem the influences of kr gas in Ne-Xe-Kr ternary gas system is investigated for wide range of Xe partial pressure in terms of operating voltage, driving margin, luminance and luminous efficacy.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.5
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• pp.361-366
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• 1999

The life of AC PDP depends largely on the sputtering-resistant property of the protecting layer such as MgO thin-film. However, it is very difficult to measure the sputtering-resistant property in the stable driving conditions of AC PDP. In this paper we have suggested a high speed measurement technique of the sputtering-resistant property of MgO thin-film by applying the MgO thin-film as the target of RF magnetron sputtering system. We have also applied this method to the e-beam MgO and sputter-MgO and e-beam MgO superior to sputter-MgO 3 times over. Also, the relation of Xe gas partial pressure(X) and sputtered thickness(Y) was Y=3.4X+13.5.

• Journal of Surface Science and Engineering
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• v.43 no.2
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• pp.80-85
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• 2010

The surfaces of WC-Co and SCM415 were etched to form a micro size protrusion for oil based ultra low friction applications using an ion bombardment process in a filtered vacuum arc plasma. WC-Co species showed that a self-patterned surface was available by the ion bombarding process due to the difference of sputtering yield of WC and Co. And the increasing rate of roughness was 0.6 nm/min at -600 V substrate bias voltage. The increasing rate of roughness of SCM415 species was 1.5 nm/min at -800 V, but the selfpatterning effect as shown in WC-Co was not appeared. When the SCM415 species pretreated by electrical discharge machining is etched, the increasing rate of roughness increased from 1.5 nm/min to 40 nm/min at -800 V substrate bias voltage and the uniform surface treatment was available.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.548-549
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• 2005

본 논문에서는 인가 전극구조가 다른 두가지 형태의 아크성 스트리머 방전용 플라즈마 반응기를 설계 제작하였다. 제작된 반응기에 60 Hz상용전원과 펄스파워를 인가전원으로 사용하여 반응기 형태와 인가전원에 따른 수소발생 특성에 대하여 조사하였다. 또한 방전 전력에 따른 수소발생량을 비교 분석하였다. 수소 발생을 위한 효과적인 수표면 방전은 강한 전계 집중과 높은 에너지 밀도를 동반한 아크성 스트리머 방전 분위기 형성이 필요하다. 인가전원으로 상용전원을 이용한 경우보다 펄스파워를 사용한 경우와 강한 전계집중 증대를 위해 인가 전극이 석영관 내에 배치된 전극 구조에서 수소발생에 효과적이였다.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.2
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• pp.176-180
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• 2018

Drug abuse and its related problems are increasing continuously in Korea. One of the most frequently abused drugs is methamphetamine, but there are few medical report in Korea. This is the first report of the identification of methamphetamine in the blood of a patient who had a return of spontaneous circulation after cardiac arrest and survived discharge. A 33-year-old male arrived at the emergency department presenting with chest pain and dyspnea. He had ingested methamphetamine and alcohol approximately 7 hours before arrival. One hour after arrival, he had seizure followed by cardiac arrest. Spontaneous circulation was recovered after 4 minutes of CPR. An analysis of the National Forensic Service identified plasma methamphetamine with an estimated average concentration of plasma methamphetamine at the time of arrival of 0.6 mg/L, a lethal dose. He had rhabdomyolysis and acute kidney injury but survived after continuous renal replacement therapy. Since then, he has suffered chronic kidney disease, and he is being followed up at the out-patient department. In Korea, although drug abuse is still uncommon, it is on the increase. Therefore, emergency physicians should be aware of the clinical characteristics of methamphetamine poisoning.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2367-2374
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• 2024

In this paper, based on the need for high-strength connections between all-tungsten-oriented plasma materials and thermal sinking materials of copper and its alloys in nuclear fusion devices, a study on the effect of tungsten surface laser micro structuring on the interfacial bonding properties of W/Cu joints was carried out. In the experiment, the connectors were prepared by vacuum fusion infiltration technology, and the effects of microgroove structure on the mechanical and thermal conductivity of W/Cu connectors were investigated under different parameters (including microgroove pitch, microgroove depth, and microgroove taper). The maximum shear strength is 126.0 MPa when the pitch is 0.15 mm and the depth is 34 ㎛. In addition, the negative taper structure, i.e., the width of the entrance of the microstructure is smaller than the width of the interior of the microstructure, is also investigated. The shear tests show that there is an approximately linear relationship between the shear strength of W/Cu and taper. Compared with the positive taper, the shear strength of the samples with the same morphological density and depth of the tungsten surface is significantly higher.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.52-59
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• 2006

This paper examined the conversion of methane to hydrogen and other higher hydrocarbons using dielectric barrier discharge with AC pulse power. Two metal electrodes of a coaxial-type plasma reactor were separated by gas gap and an alumina tube. The inner electrode was located inside the alumina tube. The alumina tube was located inside the stainless steel tube, which was used as the outer electrode. Effect of feed gas composition (methane, oxygen, argon, water and helium), flow rate, applied frequency, input volt-age on methane conversion and product distribution were studied. The major products of plasma chemical reactions were ethylene, ethane, propane, buthane, hydrogen, carbon monoxide and carbon dioxide. The increment of applied voltage and the usage of inert gas as the background (helium and argon) enhanced the selectivity of hydrocarbons and methane conversion. The addition of water in the feed stream enhanced the conversion of methane and yield of hydrogen. Higher voltage leads to higher yield of $C_2H_6,\;C_3H_8,\;C_4H_{10}$ and yield or $C_2H_2\;and\;C_2H_4$ appeared highly in lower voltage.

• Polymer(Korea)
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• v.33 no.1
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• pp.79-83
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• 2009

Thin electric insulation layers were coated on aluminum plates and aluminum condenser cases by plasma polymerization of HMDSO+$O_2$. Electric resistances of the films were higher than 1.0 M$\Omega$ if they are thicker than 0.5 ${\mu}m$ independently of the type of films but their surface morphologies and adhesion strengths were dependent on the process conditions. Deposition rate and adhesion strength of the films were dependent on $O_2$/HMDSO flow ratio and discharge power. The best result was obtained at $O_2$/HMDSO flow ratio of 4 and discharge power of 60 W. Adhesion strength could also be highly improved if aluminum was pre-treated in boiling water for 30 min through the formation of Al-O-Si bonding between the film and the aluminum surface. The coated films showed excellent chemical and thermal resistances.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.486-491
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• 2016

Efficacy of dielectric barrier discharge-cold plasma treatment (DBD-CPT) for microbial decontamination of onion powder was evaluated. Onion powder, inoculated with Escherichia coli O157:H7, Salmonella Enteritidis, or Listeria monocytogenes, was treated with helium DBD-CPT. DBD-CPT (9 kV, 20 min) inhibited E. coli O157:H7, S. Enteritidis, and L. monocytogenes by $1.4{\pm}0.5$, $2.3{\pm}0.3$, and $1.2{\pm}0.0log\;CFU/cm^2$, respectively. The inactivation levels of E. coli O157:H7, S. Enteritidis and L. monocytogenes increased by $2.2{\pm}0.1$, $2.5{\pm}0.1$ and $1.9{\pm}0.3log\;CFU/cm^2$, respectively, as water activity increased from 0.4 to 0.8, and increased by $2.3{\pm}0.4$, $2.1{\pm}0.1$ and $1.6{\pm}0.1log\;CFU/cm^2$, respectively, as the particle size increased from 0.3 to $1.0cm^2$. Neither the ascorbic acid and quercetin concentrations nor the color of onion powder was changed by DBD-CPT (p>0.05). These results demonstrate the potential for application of DBD-CPT in improving microbiological safety of onion powder while preserving the physicochemical properties.

• Journal of Powder Materials
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• v.22 no.3
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• pp.163-168
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• 2015

Ti alloys are extensively used in high-technology application because of their strength, oxidation resistance at high temperature. However, Ti alloys tend to be classified very difficult to cut material. In this paper, The powder synthesis, spark plasma sintering (SPS), bulk material properties such as electrical conductivity and thermal conductivity are systematically examined on $Ti_2AlN$ and $Ti_2AlC$ materials having most light-weight and oxidation resistance among the MAX phases. The bulk samples mainly consisted of $Ti_2AlN$ and $Ti_2AlC$ materials with density close to theoretical value were synthesized by a SPS method. Machining characteristics such as machining time, surface quality are analyzed with measurement of voltage and current waveform according to machining condition of micro-electrical discharge machining with micro-channel shape.