• 전기의세계
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• 제25권5호
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• pp.79-87
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• 1976

This paper is to investigate the A.C generation of MHD engine, converting directly the kinetic energy of conductive gas in high temperature to electric power by the effect of magnetic field. It is known that there are at least two kinds of method in A.C MHD power generation; one, by sending stationary plasma flow in an alternating or rotating magnetic field and the other, by transmission of pulse type plasma flow in uniform and constant magnetic field, former method is adopted here. In order to raise the total efficiency of close cycle in combination with nuclear power and MHD genertaion, an argon plasma jet is utilized as heat source, which is not mixed with the seed material, and the design data are obtained for A.C MHD generation in small capacity, but induced voltage and power output have the maximum values, 15 voltages and 7.5W respectively due to plasma flow with low conductivity and weak magnetic field.

• 전기학회논문지
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• 제56권5호
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• pp.933-937
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• 2007

A point plate type nonthermal plasma reactor, with a grounded cylindrical third electrode which closely- encompasses the needle point, have been investigated with an emphasis on the role of the third electrode. It was found that the point plate airgap, with the grounded third electrode, had a switching characteristic on its I V characteristics for negative and positive discharges, which is very different from that of a conventional point plate airgap without a third electrode. The corona discharge and ozone generation characteristics of the plasma reactor with the grounded cylindrical third electrode, such as the corona onset voltage. the breakdown voltage. the corona current. and the amount of output ozone, were influenced significantly by the height of the third electrode. and these characteristics can be controlled by adjusting the height of the third electrode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2092-2094
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• 2000

As a next generation lithography (NGL) technology for VLSI semiconductor fabrication, electron beam, ion beam, X-ray and extreme ultraviolet(EUV) are considered as possible candidates. Among these methods, EUV lithography(EUVL) is thought to be the most probable because it is easily realized by improving current optical lithography technology. In order to set EUV radiation which can be applied to EUVL, it is essential to generate very high density and high temperature plasma stably. The method using a pulse power laser and a high voltage pulse discharge is commonly used to accomplish such a high density and high temperature plasma. In this paper we review the recent trends of the EUV generation technique by high density and high temperature plasma.

• 공업화학
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• 제34권5호
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• pp.507-514
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• 2023

촉매(Ag/γ-Al₂O₃) 충진형 유전체 장벽 방전 플라즈마 반응기를 이용한 질소산화물(NO_x)의 선택적 촉매 환원을 조사하였다. 촉매 상에서 간헐적으로 플라즈마를 발생시킬 때 NO_x의 환원제인 탄화수소가 부분 산화되어 알데하이드류를 생성하였으며, 알데하이드류의 높은 환원력으로 인해 촉매를 단독으로 사용한 경우에 비해 높은 NO_x 전환율을 보여주었다. 동일한 운전 조건(온도: 250 ℃; C/N: 8)에서 비교한 NO_x 저감 효율은 탄화수소(n-헵테인), 프로피온알데하이드, 뷰티르알데하이드에 대해 각각 47.5%, 92%, 96%로 나타났으며, 알데하이드류의 높은 질소산화물 환원 성능이 확인되었다. 간헐적 플라즈마 발생시 적정 조건을 파악하기 위하여, 고전압 on/off 주기를 0.5~3 min으로 조절하였고, 연속적인 플라즈마 발생의 경우와 동일한 에너지밀도에서 NO_x 저감 성능을 비교하였다. 고전압을 2 min 간격으로 on/off 하여 간헐적으로 플라즈마를 생성시켰을 때 연속적인 플라즈마 발생 대비 가장 높은 질소산화물 저감 효율이 얻어졌다. 동일한 에너지밀도에서도 간헐적 플라즈마 방전의 경우가 연속 플라즈마에 비해 높은 NO_x 저감 효율을 보이는 것은, 탄화수소가 분해되어 생성되는 알데하이드류 등의 중간생성물들이 NO_x 저감 반응에 보다 효율적으로 이용되었기 때문이다.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.138-138
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• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• 한국표면공학회지
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• 제34권5호
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• pp.367-377
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• 2001

Plasma is generated by electrical discharge. Most plasma generation has been carried out at low-pressure gas typically less than one millionth of atmospheric pressure. Plasmas are in general generated from impact ionization of neutral gas molecules by accelerated electrons. The energy gain of electrons accelerated in an electrical field is proportional to the mean free path. Electrons gain more energy at low-pressure gas and generate plasma easily by ionization of neutrals, because the mean free path is longer. For this reason conventional plasma generation is carried out at low pressures. However, many practical applications require plasmas at high-pressure. In order to avoid the requirement for vacuum pumps, researchers in Korea start to develop plasmas in high-pressure chambers where the pressure is 1 atmosphere or greater. Material processing, environmental protection/restoration and improved energy production efficiency using plasmas are only possible for inexpensive bulk plasmas. We thus generate plasmas by new methods and plan to set foundations for new plasma technologies for $21^{st}$ / century industries. This technological research will play a central role in material processing, environmental and energy production industries.

• 전기학회논문지
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• 제56권4호
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• pp.773-776
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• 2007

A microstructure array has been proposed for micro plasma generation using electroplating and double exposed process. A stable atmospheric plasma has been generated at a low voltage by utilizing the micro electrode gap. Self-aligned microstructure can provide uniform electrode overlap with precisely controlled gap between the electrodes. The proposed structure allows for triode operation, which can expand the generated plasma over a large area by applying a lateral electric field. Electrical characteristics of the micro triode confirm the large numbers of the plasma ions are drifted to the secondary cathode by the lateral electrical field.

• Applied Science and Convergence Technology
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• 제23권4호
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• pp.169-178
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• 2014

Fluid model based numerical analysis is done to simulate a low damage etch back system for 20 nm scale semiconductor fabrication. Etch back should be done conformally with very high material selectivity. One possible mechanism is three steps: reactive radical generation, adsorption and thermal desorption. In this study, plasma generation and transport steps are analyzed by a commercial plasma modeling software package, CFD-ACE+. Ar + $CF_4$ ICP was used as a model and the effect of reactive gas inlet position was investigated in 2D and 3D. At 200~300 mTorr of gas pressure, separated gas inlet scheme is analyzed to work well and generated higher density of F and $F_2$ radicals in the lower chamber region while suppressing ions reach to the wafer by a double layer conducting barrier.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권9호
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• pp.413-416
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• 2002

It was reported that low temperature plasma developed by our group was apparently homogeneous and stable at atmospheric pressure, and was generated if the alumina was used as a dielectric insulating material and Ar gas as a plasma gas. This is a structure in which the dielectric materials are covered and arranged in parallel in the one side of electrode. In this experiment, we discovered that dielectric material was important to generate normal electric discharge. To examine the effect of dielectric material on the electric discharge characteristic, the voltage and current of the plasma was measured and the electrical effect of dielectric material was examined. Also, it was applied to an etching of tin oxide films.

• Korean Chemical Engineering Research
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• 제44권5호
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• pp.483-488
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• 2006

유기고분자에 대한 건식 식각공정으로 remote 플라즈마를 이용하여 유리 표면에 도포된 PMMA의 식각공정에 관한 연구로 플라즈마 출력, 반응가스, 플라즈마 발생원과의 거리에 대한 식각특성을 측정하였다. 플라즈마 발생원으로부터 멀어질수록 플라즈마에 의해 발생된 라디칼 밀도로 인해 PMMA 식각속도가 감소하였다. 플라즈마 내에서 발생된 라디칼에 의해 PMMA가 제거되며, 플라즈마 출력이 증가할수록 PMMA 표면과 반응하는 라디칼 증가로 식각속도는 선형적으로 증가하였다. 식각 기체에서 산소의 양이 증가함에 따라 식각속도 증가와 더불어 식각표면의 거칠기도 증가함을 알 수 있었다.