평판형 마그네트론 스퍼터 시스템의 RF 방전특성 및 플라즈마 진단

곽동주 경성대학교 공학기술연구소 1998 공학기술연구지 Vol.5 No.-

Electrical characteristics and plasma parameters of RF discharge driven at 13.56MHz in a parallel-plate magnetron sputtering system were measured since they may be considered as the important factors deciding the thin film properties. From these measurements the interpretation on the dissipation mechanism of RF power was carried out, and the relationships between electron temperature and density as parameters of RF power and position were discussed.

압축응력하의 PET박막의 절연강도특성에 미치는 연신의 효과

곽동주 慶星大學校 1991 論文集 Vol.12 No.3

The electrical insulators for superconducting maget coils to be used in a large fusion reactor are subjected to large mechanical stress, and this stress should pose a significant electrical insulating problem in practice. In this paper, the dc dielectric strength characteristics of uniaxially and biaxially drawn PET films under compressive stress were investigated. Samples were heat set in silicon oil over a range of temperature between 120� to 220� for durations of 1 and 60 min. in order to control the degree of crystallinity of the sample. The results show that the dielectric strength of PET film increases at first with increasing compressive stress, reaches a maximum value and thereafter decreases gradually. This stress-dependency of dielectric strength can be seen in various films with different crystallininties, and the compressive stress showing the maximum dielectric strength may be a mechanical service limit point of that film. In the biaxially drawn PET, the sample heat-treated at 140� shows the highest dielectric strength under compressive stress regardless of annealing time.

원통형 스퍼터링 시스템의 글로우 방전특성

곽동주 경성대학교 생산기술연구소 1996 생산기술연구지 Vol.3 No.-

In this paper, the glow discharge characteristics and plasma parameters of both facing target sputtering (FTS) and cylindrical magnetron sputtering (CPMS) systems are studied experimentally. It is found that these two systems show different discharge characteristics under magnetic field and pressure. For CPMS system discharge is stablized under wider ranges of magnetic field and pressure than for FTS system. The plasma density and electron temperature of the plasma for these two systems are in the range of ??, respectively.

油中部分放電을 경유한 PET 박막의 異常絶緣破壞특성

곽동주 慶星大學校 1992 論文集 Vol.13 No.2

The dc and impulse dielectric strengths of PET film are measured, using molded sphere to plane electrode configuration in transformer oil. The electric breakdown in the present test has two types of discharge paths one corresponds to the puncture without surface discharge and the other is the puncture with partial discharge in transformer oil-PET composite insulating system. These are called normal and anomalous breakdowns, respectively in this paper. The anomalous breakdown voltages with partial discharges are very important as the practical data for the insulation design of electric machine. Hence, brief interpretation about the anomalous breakdown characteristic of various PET films with different crystallinities and sample thickness is made, including also the normal breakdown. The dielectric strength at anomalous breakdown is lower than the intrinsic dielectric strength of PET film, and the anomalous breakdown occurs easily under the conditions of impulse electric fields and lower compressive stress.

Peripheral Blood NK Cells Reflect Changes in Decidual NK Cells in Women With Recurrent Miscarriages

Park, Dong Wook,Lee, Hyun Joo,Park, Chan Woo,Hong, Sung Ran,Kwak-Kim, Joanne,Yang, Kwang Moon Blackwell Publishing Ltd 2010 American journal of reproductive immunology Vol.63 No.2

<P><B>Citation</B> Park DW, Lee HJ, Park CW, Hong SR, Kwak-Kim J, Yang KM. Peripheral blood NK cells reflect changes in decidual NK cells in women with recurrent miscarriages. Am J Reprod Immunol 2010; 63: 173–180</P><P>Problem </P><P>We aimed to investigate if peripheral blood natural killer (pNK) cell levels are correlated with decidual NK (dNK) cell levels, and if chemokine expression has any role in dNK cell regulation.</P><P>Method of study </P><P>Decidual tissues of women having two or more miscarriages with normal karyotype were collected after miscarriage and an immuno-histochemisty study was made. pNK cells were evaluated using flow cytometric analysis.</P><P>Results </P><P>The %CD3<SUP>−</SUP>/56<SUP>+</SUP> and %CD3<SUP>−</SUP>/56<SUP>+</SUP>/16<SUP>+</SUP> pNK cells showed a significant correlation with mean number of CD56<SUP>+</SUP> dNK cells. The number of decidual CD16<SUP>+</SUP> cells was significantly higher in women with elevated pNK (≥15%) than that of normal pNK (<15%). The %CD3<SUP>−</SUP>/56<SUP>+</SUP> and %CD3<SUP>−</SUP>/56<SUP>+</SUP>/16<SUP>+</SUP> pNK cells showed an inverse correlation with duration of gestation. The CCL3<SUP>+</SUP> and CXCL12<SUP>+</SUP> cells were present in the decidua; however, staining intensity was not correlated with number of dNK cells.</P><P>Conclusion </P><P>The pNK cell levels reflect changes in dNK cell levels. This implicates that pNK cell level is a clinically useful marker to predict pregnancy outcome. Further study is needed to examine if elevated pNK cells enhance recruitment of dNK cells in the decidua.</P>

다중이용업소에서 사용하는 실내장식재에 대한 방화ㆍ방염제도 개선에 관한 연구

박형주,곽동일 한국화재소방학회 2001 한국화재소방학회논문지 Vol.15 No.1

90년대 후반기부터 연이어 발생한 씨랜드 화재사고와 인천 인현동 라이브클럽 화재등의 동일한 유형을 가진 화재사건을 계기로 국내 다중이용업소의 실내장식재 및 장식물품에 사용하는 재료가 화재시 인명참사에 미치는 영향이 크다는 점이 발견되었다. 따라서 군내다중이용업소를 중심으로 실내장식재 및 장식물품의 사용과 관련한 화재안전규정 및 기준을 조사한 후에 유럽 · 미국등의 선진국의 관련 규정을 조사 비교하여 그 문제점을 세부적으로 발췌하여 규제방향 및 규제기준의 상이점을 분석하여 대형인명참사를 초래하는 근본적인 원인을 찾아내었다. 고찰된 원인을 근간으로 실내장식재 및 장식물품에 사용하는 재료가 선진국 수준의 방재성능을 가질 수 있도록 규제방향을 제시하고 제시된 규제방향을 뒷받침할 수 있는 효과적이고 검증된 시험방법을 연구제시하였다. 최종적으로 향후 발생가능한 대형인명참사를 효과적으로 방지하기 위해 다중이용업소를 중심으로 방화 및 방염제도의 효과적인 수립이 되도록 실내장식재 및 장식물 품에 대한 세부규제안을 기술하여 방화 및 방염제도의 세부규제안을 제시하였다. Similar patterned fire incidents such as, Inchon Live-Hof Pun Restaurant as, Sea-land Children Resort have proven that serious loss of lives were caused by hazardous gas generated from a combustion of interior finish and decorative materials. Therefore, comparing Korean fire regulation with other countries fire code, e.g. UK, USA, France about limitation of interior finish and decorative materials in premises as assemblies, differences & problems have been investigated and analyzed on how serious they may affect on fire spread and smoke development based on analyzed facts. It is suggested that Korean fire code would be revised in order to reduce hazardous interior finish materials from special occupancy and adapted new test methods to verify proper fire performance in premises as assembles which require a fire certificate. Finally, detailed code alternatives will be suggested in order to set up effective fire regulation, which could promote preventing serious loss of lives in future.

대기압 스트리머 코로나방전특성 및 이산화탄소 전환특성

조문수,김학규,곽동주,신용섭 경성대학교 공학기술연구소 2001 공학기술연구지 Vol.8 No.-

Deep interests have been paid on the application of non-thermal plasma technique th solve the environmental pollution problems. CO_2 is one of the severe pollutants which cause the acid rain and global warming. In this study, in order to improve the conversion efficiency of CO_2, the streamer corona discharge plasma and barrier discharge plasma reactors were made, and the conversion characteristics of CO_2 by the corona discharge plasma and some discharge characteristics of these discharge chambers are studied experimentally.

ZnO:AI 박막의 전기적 특성에 미치는 RF 방전 파라메타의 영향

이성욱,김병섭,곽동주 경성대학교 공학기술연구소 2003 공학기술연구지 Vol.S1 No.1

In this paper, in order to obtain an excellent transparent conducting thin film with low resistivity and high optical transmittance for Plasma Display Panel (PDP), aluminum doped zinc oxide films were deposited on Corning glass substrate by rf magnetron sputtering method. The volume resistivity of the film was strongly influenced by the Ar pressure, substrate temperature, rf discharge power and Al doping contents. The lowest volume resistivity of 7×10^(-4) Ω-cm, associated with a transmittance of 89 % were obtained under the conditions of lmtorr and 400℃ in argon pressure and substrate temperature, respectively. The diffraction peaks of the film also became more intense and narrower with decreasing Ar pressure and increasing substrate temperature up to 400 ℃.

글로우 방전을 이용한 이산화탄소의 전환특성

신용섭,송승훈,곽동주 慶星大學校 1998 論文集 Vol.19 No.2

In this study, the characteristics of CO₂conversion and glow discharge were investigated using glow discharge plasma reactor with a parallel copper electrode system. A pure CO₂ gas was used for the carrier gas under gas pressure of 10∼80 torr in a glow discharge. For glow discharge, discharge current was increased with the increase of discharge voltage. In the case of constant discharge voltage, the discharge current tend to increase with the decreasing of gas pressure. Using pure CO₂only, the CO₂conversion was increased with the increase of discharge power and the decreased of gas pressure. The maximum CO₂ conversion was 28% at 10 torr, 598 W, 902.4V. Energy yield was decreased with the increase of discharge power and discharge voltage. Also, the concentrations of CO₂and O₂in the produced gas were slightly increased with the increase of CO₂ conversion.

ZnO:AI 과 ITO 투명전도막을 이용한 플랙시블 DSCs의 변환효율 특성

정기영,김지훈,성열문,곽동주,추영배 경성대학교 공학기술연구소 2010 공학기술연구지 Vol.16 No.-

In order to investigate the possible application of ZnO films as a transparent conducting oxide (TCO) electrode for film-typed dye sensitized solar cell(F-DSC), ZnO:Al films were prepared by RF magnetron sputtering method. The effects of gas pressure on the structural and electrical properties of ZnO films were mainly studied experimentally. F-DSC using either a ZnO:Al or indium tin oxide (ITO) electrode were also fabricated separately under the same manufacturing conditions. The electro-optical conversion efficiency and fill factor of the F-DSCs using both ZnO:Al and ITO transparent conducting electrodes were measured and compared with each other. ZnO:Al films showed the minimum resistivity of 2.6 x10^(-3)Ω-cm and a transmittance of 91.7% under the experimental conditions of doping concentration of 2 wt% of Al₂0₃ and gas pressure of 5mTorr. ITO films fabricated at 5mTorr of gas pressure also showed the minimum resistivity of 1.5x10^(-3)Ω-cm and transmittance of 92.1%. Although the electrical resistivity of ZnO:Al is higher than that of ITO, the conversion efficiency of F-DSC using ZnO:Al was comparable with that of F-DSC using ITO. The conversion efficiency of F-DSCs using ZnO:Al and ITO electrodes are about 2.8% and 2.9%, respectively.