• 한국진공학회지
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• 제18권3호
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• pp.151-163
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• 2009

유체 모델을 기반으로 하는 국내의 유도 결합 플라즈마원의 시뮬레이터 개발 현황을 정리하였다. 전체 시뮬레이터를 구성하는 각 부분으로서, 전자 가열, 하전 입자 및 중성종 수송, sheath를 포함한 표면 반응, 그리고 GUI (Graphic User Interface) 및 전후처리기 등의 순으로 설명되었다. 현재까지 시뮬레이터에 구현된 화학 반응 데이터와 swarm 데이터도 정리하여 보았고, 앞으로의 개발 방향을 전망하여 보았다.

• 대한수의학회지
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• 제29권4호
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• pp.469-474
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• 1989

The changes of plasma prostaglandin $E_2$ level, natural killer cell activity and tumor cell growth were assayed after transplantation of EL-4 leukemia cells in C57BL/6 mice. The results were summarized as follows; 1. Plasma prostaglandin $E_2$ level was increased in EL-4 bearing mice, but indomethacin treated mice group showed low level. 2. The tumor-derived prostaglandin $E_2$ inhibited the post-target binding cytolytic process of natural killer activity. 3. Indomethacin inhibited the growth of prostaglandin secreting EL-4 solid tumor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1619-1621
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• 1994

Both Facing Target Sputtering(FTS) and Cylindrical Post-Magnetron Sputtering(CPMS) systems have been degigned in order to form high density plasma and to obtain high deposition rate. However, these two systems have some different applications, and discharge characteristics of these two systems are not well known. In this paper, the discharge characteristics and plasma parameters of both FTS and CPMS systems are studied experimentally. It is found that these two system show some different discharge characteristics under magnetic fields. The plasma density and electron temperature of these two systems are in the range of $10^{10}{\sim}10^{11}[cm^{-3}]$ and $3.5{\sim}5.5[eV]$, respectively.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권4호
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• pp.770-783
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• 2015

Lately, high production rate welding processes for Al alloys, which are used as LNG FPSO cargo containment system material, have been developed to overcome the limit of installation and high rework rates. In particular, plasma-metal inert gas (MIG) hybrid (PMH) welding can be used to obtain a higher deposition rate and lower porosity, while facilitating a cleaning effect by preheating and post heating the wire and the base metal. However, an asymmetric undercut and a black-colored deposit are created on the surface of PMH weld in Al alloys. For controlling the surface defect formation, the wire feeding speed and nozzle diameter in the PMH weld was investigated through arc phenomena with high-speed imaging and metallurgical analysis.

• Journal of Chest Surgery
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• 제21권4호
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• pp.613-618
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• 1988

The exposure of blood to foreign materials can cause the denaturation of plasma protein components such as immunoglobulins and complements. And those phenomena increase the morbidity and mortality after intracardiac operations through the cardiopulmonary bypass. From April, 1987 to September, 1987, we had observed the serial changes of plasma total protein IgG, IgA, IgM, complements[C3, C4] in bubble oxygenator group[n=5] and membrane oxygenator group[n=5]. Statistically significant difference between two groups were present in total protein and C3. We conclude that using membrane oxygenator in long extracorporeal circulation can reduce the activation of alternative pathway of complement system, and which can reduce post-perfusion complications of the lung though we can`t prove it in mass populations.

• 한국표면공학회지
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• 제54권6호
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• pp.307-314
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• 2021

Diamond-like carbon (DLC) is difficult to achieve sufficient adhesion because of weak bonding between DLC film and the substrate. The purpose of this study is to improve the adhesion between substrate and DLC film. DLC film was deposited on AISI H13 using linear ion source. To improve adhesion, the substrate was treated by dual post plasma nitriding. In order to define the mechanism of the improvement in adhesive strength, the gradient layer between substrate and DLC film was analyzed by Glow Discharge Spectrometer (GDS) and Scanning Electron Microscope (SEM). The microstructure of the DLC film was analyzed using a micro Raman spectrometer. Mechanical properties were measured by nano-indentation, micro vickers hardness tester and tribology tester. The characteristic of adhesion was observed by scratch test. The adhesion of the DLC film was enhanced by active screen plasma nitriding layer.

• 한국식품위생안전성학회지
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• 제31권5호
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• pp.375-379
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• 2016

국내 시판 중인 선식의 유통 안전성 확보를 위한 기초 기반연구로 대기압 플라즈마 처리한 선식의 품질 특성 평가를 진행하였다. 본 연구에서 이용한 플라즈마는 컨테이너형 유전격벽 플라즈마로 방전 가스는 공기를 활용하여 0, 5, 10 및 20분 처리하였고 미생물 감균효과, 색도, pH 관능평가를 진행하였다. 일반 호기성 미생물 분석 결과 20분 처리 시 약 1.70 log CFU/g 감소하였으며 B. cereus, B. subtilis 및 E. coli O157:H7을 이용한 접종 시험 결과 각각 2.20, 2.22 및 2.50 log CFU/g 감소하였다. 색도 측정결과 플라즈마 처리에 의해 명도 값은 증가하였으나 적색도 및 황색도는 감소하였다. 플라즈마 처리에 의한 선식의 pH 측정 결과 처리시간에 따라 감소하는 경향을 보였다. 하지만 플라즈마 처리에 의해 단백질 지질산화가 일어나 관능 품질이 저하되는 경향을 보였다. 따라서 공기로 방전된 대기압 플라즈마 기술은 선식의 품질안전성을 개선할 수 있으나, 관능적 품질 특성 개선을 위한 후속연구가 필요하다고 판단된다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제7권1호
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• pp.77-91
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• 1996

틱장애 아동들의 생화학적인 원인을 규명하고, 동반 질환과의 관계를 규명하기 위하여 87명의 틱장애 아동과 30명이 대조군을 대상으로 하여 다음과 같은 결과를 얻었다 87명 중 45명은 Tourette씨병(TS)이었고, 22명은 만성틱장애(chronic motor tic disorder, CMT), 20명은 일과성틱장애(transient tic disorder, TTD)이었다. 공존질병에 따른 분류로는 순수한 틱군(PT)은 43명, 틱과 주의력결핍 과잉운동장애(attention deficit hyperactivity disorder, T+ADHD)가 동반된 군이 28명, 틱과 강박장애(obsessive compulsive disorder, T+OCD)가 동반된 군이 16명이었다. 이들 대상군과 대조군에 대하여 혈장 5- HT(5-hydroxytryptamine)와 5-HIAA(5-hydroxyindoleacetic acid)를 측정하여 다음과 같은 결과를 얻었다. 1) 혈장내 5-HT함량과 5-HTAA함량 간에는 통계적으로 의미있는 상관성이 관찰되었다(Pearson correlation coefficient, 0.77, p<0.05). 2) 대상군에서 연령과 5-HT또는 연령과 5-HIAA함량과는 통계적으로 의미있는 상관성이 관찰되지 않았다. 3) 대조군에서 연령과 5-HT또는 연령과 5-HIAA함량과는 통계적으로 의미있는 상관성이 관찰되지 않았다. 4) 혈장 내의 5-HT함량은 TS, CMT, TTD그리고 대조군간에 통계적으로 의미있는 차이가 관찰되었으며 (F=34.48, df=3.113. p<0.01), 사후검증에서는 대조군과 TS군, 대조군과 CMT군, 대조군과TTD군간에는 의미있는 차이가 관찰되었으나, TS군과 CMT군 TS군과 TTD군, 그리고 TTD군과CMT군 간에는 의미있는 차이가 없었다. 5) 혈장 내의 5-HIAA함량은 TS군, CMT군, TTD군 그리고 대조군 간에 통계적으로 의미있는 차이가 관찰되었으며(F=26.48, df=3,113, p<0.01), 사후검증에서는 대조군과 TS군, 대조군과 CMT군, 대조군과 TTD군 간에는 의미있는 차이가 관찰되었으나. TS군과 CMT군 TS군과 TTD군, 그리고 TTD군과 CMT군 간에는 의미있는 차이가 없었다. 6) 공존질병의 생화학적 소견에 미치는 영향에 대하여는 혈장 내의 5-HT와 5-HIAA함량은 PT군, T+ADHD군, T+OCD군 그리고 대조군간에 통계적으로 의미있는 차이가 관찰되었으며 (5-HT, F=37.59, df=3, 113, p<0.01, 5-HIAA, F=27.37, df=3, 113, p<0.01), 사후검증에서는 대조군과 PT군. 대조군과 T+ADHD군, 대조군과 T+OCD군간에는 통계적으로 의미있는 차이가 관찰되었으나, PT군과 T+ADHD군, PT군과 T+ADHD군, PT군과 T+OCD군, 그리고 T+ADHD군과 T+OCD군간에는 의미있는 차이가 관찰되지 않았다. 이상의 결과로 미루어 serotonin계의 개체발생적인 과정은 대상군과 대조군에서 차이가 없으나, serotonin계의 기능저하가 틱장애의 발병과 관련이 있다고 할 수 있으며, 공존질병이 생화학적인 소견에 미치는 영향은 극미하다고 할 수 있다. 향후의 연구에 있어서는 틱장애에 대하여 serotonin계의 기능항진을 일으키는 약물 투여의 효과에 대한 연구가 시행되어야 하며 분자생물학적인 방법을 사용하여 그 기전을 규명하여야 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제9권2호
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• pp.165-170
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• 1996

Two experiments were conducted to search factor(s) affecting the plasma allantoin concentration in infant calves. In experiment 1, five male Holstein calves aged 1 week were given only milk replacer free from nucleic acids for 28 days Plasma allantoin concentration varied in a reverse proportion to daily amounts of milk replacer, and the concentration when calves received 750 g/d of milk replacer was significantly lower than that when they received 250 g/d. Contrary to plasma allantoin concentration, glomerular filtration rate(GFR) was directly proportional to daily amounts of milk replacer, leading to a constant filtration of allantoin across the glomeruli. Renal handling of allantion was also unaffected by the amount of milk replacer, resulting in the constant urinary excretion of allantoin. These results suggested that GFR, which was affected by the nutritional status, could affect plasma allantoin concentration. In experiment 2, the effect of age-related changes in nutritional status after weaning on GFR was examined in eight calves weaned at 5 weeks of age. The GFR expressed as body weight basis was lower immediately after weaning, but linearly increased up to the 19th week post-weaning. The present results suggested that the changes in GFR in response to nutritional status would be one of the possible causes of atypical plasma allantoin concentration immediately after weaning. We conclude that plasma allantoin concentration would not be a proper estimator of intestinal flow of microbial protein in cattle.

• 대한금속재료학회지
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• 제46권3호
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• pp.125-130
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• 2008

Conventional plasma carburizing or nitriding for austenitic stainless steels results in a degradation of corrosion resistance. However, a low temperature plasma surface treatment can improve surface hardness without deteriorating the corrosion resistance. The 2-step low temperature plasma processes (the combined carburizing and post nitriding) offers the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. In the present paper, attempts have been made to investigate the influence of the introduction of Ar gas (0~20%) in nitriding atmosphere during low temperature plasma nitriding at $370^{\circ}C$ after low temperature plasma carburizing at $470^{\circ}C$. All treated specimens exhibited the increase of the surface hardness with increasing Ar level in the atmosphere and the surface hardness value reached up to 1050 HV0.1, greater than 750 $HV_{0.1}$ in the carburized state. The expanded austenite phase (${\gamma}_N$) was observed on the most of the treated surfaces. The thickness of the ${\gamma}_N$ layer reached about $7{\mu}m$ for the specimen treated in the nitriding atmosphere containing 20% Ar. In case of 10% Ar containing atmosphere, the corrosion resistance was significantly enhanced than untreated austenitic stainless steels, whilst 20% Ar level in the atmosphere caused to form CrN in the N-enriched layer (${\gamma}_N$), which led to the degradation of corrosion resistance compared with untreated austenitic stainless steels.