• Journal of Microbiology
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• v.44 no.3
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• pp.269-275
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• 2006

Atmospheric-pressure cold plasma (APCP) using helium/oxygen was developed and tested as a suitable sterilization method in a clinical environment. The sterilizing effect of this method is not due to UV light, which is known to be the major sterilization factor of APCP, but instead results from the action of reactive oxygen radicals. Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae deposited on a nitrocellulose filter membrane or Bacillus subtilis spores deposited on polypropylene plates were exposed to helium/oxygen plasma generated with AC input power at 10 kHz, 6 kV. After Plasma treatment, nitrocellulose filter membranes were overlaid on fresh solid media and CFUs were counted after incubation overnight. D-values were 18 sec for E. coli, 19 sec for S. aureus, 1 min 55 sec for S. cerevisiae, and 14 min for B. subtilis spores. D-values of bacteria and yeast were dependent on the initial inoculation concentration, while the D-value of B. subtilis spores showed no correlation. When treated cells were observed with a scanning electron microscope, E. coli was more heavily damaged than S. aureus, S. cevevisiae exhibited peeling, and B. subtilis spores exhibited shrunken morphology. Results showed that APCP using helium/oxygen has many advantages as a sterilization method, especially in a clinical environment with conditions such as stable temperature, unlimited sample size, and no harmful gas production.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.131-134
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• 2005

PDP 방전 셀의 최적화 및 진공자외선 발광효율을 향상시키기 위한 목적으로 AC - PDP 미소방전에서 제논 여기종 원자의 밀도를 측정하는 레이저 흡수법을 개발하였다. 본 연구에서는 PDP 셀의 기체 압력을 350Torr, 제논 함량 10%로 고정하고, 전극 위에서의 여러 위치에서 준안정 준위 제논의 밀도를 흡수법으로 측정하였다. 실험 결과 제논 여기종의 밀도의 최대값은 전극의 위치(가장자리에서 안쪽으로의 거리)가 $50{\mu}m$, $120{\mu},\;150{\mu}m$ 일 때 $3.5{\times}10^{12}cm^{-3}$, $2.8{\times}10^{12}cm^{-3}$, $2.2{\times}10^{12}cm^{-3}$로 나타났다.

• 전기의세계
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• v.24 no.1
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• pp.75-85
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• 1975

In order to develop the commercial frequency (60Hz) plasma torch of small capacity for material cutting, welding and other industrial heating, the A.C plasma jet generator of non-transfered type is made domestically and the electrode configurations of plasma torch are composed of two kinds of electrodes W-C and W-Cu, combined by thermal emission and field emission electrode materials. In this paper, the characteristics of input power, thermal efficiency, electrode consumption, the flame and forms of arc voltage and arc current for A.C plasma torch are investigated in relation to such variables as arc current, argon flow and magnetic field intensity to obtain the basic design data necessary to A.C plasma jet generator. The result are as follows; (1)The input power, thermal efficiency and electrode consumption are influenced greatly by argon flow, magnetic field intensity and nozzle materials. (2)A.C arc voltage and current are non-symmetrial, involving D.C Component. Due to this current of D.C Component, transformer core is saturated and a large abnormal current flows into the primary winding coil. In order to prevent this abnormal current flow, a condenser must be connected in series to the main discharge circuit. (3)The stability and sharpness of jet flame are improved more in the torch of W-C electrode configuration than in the torch of W-Cu electrode configuration.

• The Korean Journal of Nuclear Medicine
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• v.5 no.2
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• pp.1-6
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• 1971

The correlation between the plasma insulin, and glucose concentration was studied in healthy Korean adults consisting of 20 males and 22 females of 16 to 38 years of age. The blood samples of above subjects were obtained through cubital vein at arbitrary times, during their usual working hours. Plasma insulin was assayed by means of double antibody system of radioimnmunoassy technics, and blood glucose was determined by means of Van Slyke-Folch method. Results were as follows: 1. There were no differences in the blood sugar levels in relation to the plasma insulin concentration either by sex or age. 2. In the case, when the plasma insulin concentration was within $200m{\mu}D/ml$, the correlation between the insulin, and glucose concentration existed, the ratio of which was expressed as; Plasma glucose concentration(mg/dI)=$91.9+0.08{\times}Insulin$ concentration r=0.62 3. Insulinogenic index was 12.4%, which was somewhat higher than other reports. 4. It is suggested that the correlation between plasma insulin and glucose concentration could be determined at arbitrary times instead of fasting times.

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.146-146
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• 2004

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2046-2051
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• 2015

Currently, most high-voltage gas circuit breakers (CBs) include asymmetrical geometries in the shield, the tank, the hot-gas exhaust, and the connection parts for bushings. For this reason, a 3-dimensional (3-D) analysis of the insulation capability is necessary, rather than a 2-D analysis. However, a 3-D analysis has difficulties due to the computational time and complex modeling. This paper presents a 3-D analysis considering the asymmetry in high-voltage gas CBs and a technique to reduce the calculation time. In the proposed technique, the arc plasma requiring the most computational time is first calculated by a 2-D analysis. Then, the results such as pressure, temperature, and velocity are input as a source for the 3-D analysis. This technique is applied to a 145kV self-blast-type CB and the analysis result exhibits good agreement with the experimental result.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.242.1-242.1
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• 2014

The electron cyclotron resonance plasma source with a belt-type magnet assembly (BMA) is designed for effective plasma confinements. For characterizing the plasma source, the plasma parameters are measured by Langmuir probe. However, the plasma parameters and the motion of charged particles near the ECR zone are not easy to diagnostics, because of the high plasma density and temperature. Thus, as an alternative method, the electromagnetic simulation of the plasma source has been performed by using three-dimensional particle-in-cell and Monte Carlo collisional (PIC-MCC) simulation codes. For considering the limitation of simulation resources and time, the periodic boundary condition is applied and the coulomb collision is neglected. In this paper, we present the results of 3D PIC simulations of ECR plasmas with BMA and we compare them with the experimental results.

• Applied Science and Convergence Technology
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• v.23 no.4
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• pp.161-168
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• 2014

A real-time monitoring of immersed antenna type inductively coupled plasma (ICP) was done with a homemade 2 dimensional voltage probe array to check the uniformity of the plasma. Measured voltage values with a high impedance voltmeter are close to the floating potential of the plasma. As the substrate carrier was moving into a magnetron sputtering plasma diffusive from a $125mm{\times}625mm$ size cathode, measured results showed reliably separation of plasma into the upper and lower empty space over the carrier. Infra red thermal imaging camera was used to observe the cross corner effect in situ without eroding a target to the end of the usage. 3 dimensional particle trace model was used to analyze the magnetron discharge's behavior.

• Journal of Nutrition and Health
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• v.31 no.3
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• pp.297-304
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• 1998

Cigarette smoking is a well known risk factor for cardiovascular disease and has negative effects on blood lipid and lipoprotein . Some of the associations between smoking and chronic disease can be attributed to the less healthful lifestyles of smokers. A large body of epidemiologic evidence suggests inverse relationships between ischemic heart disease and plasma vitamin C and E concentrations . Smokers have lower plasma concentrations of these vitamins than do nonsmokers. Smokers therefore need antioxidant vitamin supplementation. The purpose of this study was to investigate the effect vitamin supplementation on plasma lipid patterns in smoking college men. 24subjects were divided into 3 groups of which were the vitamin C supplementation group (n=8), the vitamin E supplementation group(n=8) and the vitamin C+E supplementation group(n=8). The vitamin C supplementation group consumed 500mg of ascorbic acid, the vitamin E supplementation group consumed 200IU of D-$\alpha$-tocopherol, and the vitamin C+E supplementation group consumed 500mg of ascorbic acid+ 200IU of D-$\alpha$-tocopherol for 4 weeks. We examined the plasma lipid patterns before and after the vitamins were supplemented. The results obtained were as follows ; In the vitamin C supplementation group, the concentration of total cholesterol decreased significantly and HDL-cholesterol increased significantly with the supplementation of vitamin. In the vitamin E and vitamin C+E supplementation groups, however, there were no significant differences observed with the supplementation of vitamin. Concentration of plasma LDL, triglyceride, free fatty acid were not significantly affected by the supplementation of vitamin in all groups. In terms of plasma fatty acid composition, the concentrations of saturated fatty acid were not significantly affected by the supplementation of vitamin in all groups. The concentrations of palmitoleic acid, arachidonic acid, and docosahexaenoic acid, however, significantly increased in the vitamin E supplementation group(p<0.05). The concentration of plasma linoleic acid significantly increased in the vitamin C+ E supplementation group)(p<0.05). The results of this study show that antioxidant vitamin supplementation in smokers has a tendency to decrease coronary heart disease risk in view of the plasma total cholestrol and HDL-cholesterol concentrations of the vitamin C supplementation group and fatty acid concentration of the vitamin E supplementation group.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.3
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• pp.150-155
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• 2010

Generally, plasma nitriding process has composed with a nitriding layer within glow discharge region occurred by energy exchange. The dissociations of nitrogen molecules are very difficult to make neutral atoms or ionic nitrogen species via glow discharge area. However, the captured electrons in which a double-folded screen with same potential cathode can stimulate and come out some single atoms or activated ionic species. It was showed an important thing that is called "hat is a dominant component in this nitriding process?" in plasma nitriding process and it can take an effective species for without compound layer. During a plasma nitriding process, it was able to estimate with analyzing and identification by optical emission spectroscopy (OES) study. And then we can make comparative studies on the nitrogen transfer with plasma nitriding and ATONA process using plasma diagnosis and metallurgical observation. From these observations, we can understand role of active species of nitrogen, like N, $N^+$, ${N_2}^+$, ${N_2}^*$ and $NH_x$-radical, in bulk plasma of each process. And the same time, during DC plasma nitriding and other processes, the species of FeN atom or any ionic nitride species were not detected by OES analyzing.