• Tribology and Lubricants
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• 제19권2호
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• pp.109-115
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• 2003

Nanotribological characteristics between a Si$_3$N$_4$ AFM tip and hydrophobic thin films were experimentally studied. Tests were performed to measure the nano adhesion and friction in both AFM (atomic force microscope) and LFM (lateral force microscope) modes in various .ranges of normal load. Plasma-modified thin polymeric films were deposited on Si-wafer (100). Results showed that wetting angle of plasma-modified thin polymeric film increased with the treating time, which resulted in the hydrophobic surface and the decrease of adhesion and friction. Nanotribological characteristics of these surfaces were compared with those of other hydrophobic surfaces, such as DLC, OTS and IBAD-Ag coated surfaces. Those of OTS coated surface were superior to those of others, though wetting angle of plasma-modified thin polymeric film is higher.

• Tribology and Lubricants
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• 제12권3호
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• pp.33-38
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• 1996

High temperature wear behaviors of plasma-sprayed ZrO$_{2}$-$Y_{2}O_{3}$ composite coatings were investigated for high temperature wear resistance applications. The composite powders containing 20, 50, 80 vol% of alumina for plasma spray were made by spray drying method. Wear tests with composite coated specimens were performed at temperature ranges from room temperature to 800$^{\circ}$C. Wear tests were also carried out with heat treated specimens at room temperature. The microstructural change of coatings and the worn surface were examined by SEM and XRD. Sharp increase of wear loss at high temperature wear test was observed in specimens containing 50 and 80 vol% alumina. Similar trend was observed in the heat treated coatings. The measured residual stress was increased with increased alumina contents and heat treating temperatures. Residual stress induced during heat treatment appeared to be responsible to the observed harmful effect of alumina additions on the high temperature wear.

• 한국대기환경학회지
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• 제19권2호
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• pp.157-165
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• 2003

A combined process of non-thermal plasma and catalytic technique has been investigated to treat $CH_3$CN gas in the atmosphere. A planar type dielectric barrier discharge (DBD) reactor has been used to generate the non-thermal plasma that produces various chemically active species, such as O, N, OH, $O_3$, ion, electrons, etc. Several different types of the beads. which are Molecular Sieve (MS) 5A, MS 13X, Pt/alumina beads, are packed into the DBD reactor, and have been tested to characterize the effects of adsorption and catalytic process on treating the $CH_3$CN gas in the DBD reactor. The test results showed that the operating power consumption and the amounts of the by-products of the non-thermal plasma process can be reduced by the assistance of the adsorption and catalytic process.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.136-143
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• 1995

With the contact angle of phase dropping epoxy resin on the inorganic filler(glass plate) surface treated with air plasma, we have studied about the interfacial wettability between epoxy resin and glass plate as a simple model of glass fiber reinforced composite materials. The contact angle on the inorganic filler surface varied with surface treatment conditions. The contact angle significantly depends on plasma treating time and environment temperature in the oven. From the view point of plasma treatment condition in this work, when discharge conditions were pressure 200mtorr, voltage 800V, magnetic flux density 8OGauss, optimum treatment time were proved as 3,4 and 5 minutes for the environment of >$80^{\circ}C$, >$100^{\circ}C$ and >$120^{\circ}C$, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1489-1490
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• 2011

The $O_2$ plasma treatment is used as improvement of ITO roughness glass for organic light-emitting diodes and organic photovoltaic cells. This study examined the effect of the electrical properties of OLED according to variation of $O_2$ plasma power. In experiment, we found that the electrical characteristics of device are excellent when the power of $O_2$ plasma is 250 W. And when the power of $O_2$ plasma increases over 250 W, the electrical properties were getting worse. $O_2$ plasma treatment not only prevents the diffusion of indium, a metal constituent, to an organic layer but also plays a significant role as improvement of ITO roughness. By considering organic light-emitting diodes treating $O_2$ plasma, it could contribute to the improvement of the efficiency of the device.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.157-162
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• 2002

The characteristics of DeNOx conversion process by plasma/post-heating system with the simulated gas containing ethene is investigated experimentally. Without plasma treatment, $NO-NO_2$ conversion doesn't occur by $400^{\circ}C$ in a mixture of $N_2/O_2$ with a trace gas of ethene. But $NO-NO_2$ conversion occurs as temperature increases above $400^{\circ}C$. The NO can, however, be converted to $NO_2$ at lower temperatures by treating the gas mixture with non-thermal plasma. The $NO-NO_2$ conversion enhances further by passing the plasma treated gas through the post-heating furnace. Results show that 20%${\sim}50%$ more conversion of NO to $NO_2$ is observed when the temperatures of the post-heating furnace are maintained at $300^{\circ}C$ or $400^{\circ}C$. The additional $NO-NO_2$ conversion by post-heating is due to the reaction of ethene with the byproducts or radicals generated from the plasma reaction.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.66.1-66.1
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• 2015

Plasma medicine is an upcoming research area that has attracted the scientists to explore more deeply the utility of plasma. So, apart from the treating biomaterials and tissues with plasma, we have studied the effect of plasma with different feeding gases on modification of biomolecules. Additionally, we have checked the action of nanosecond pulsed plasma on the biomolecules. We have checked the plasma action on proteins ((Hemoglobin (Hb) Myoglobin (Mb) and lysoenzyme), calf thymus DNA and amino acids. The structural changes or structural modification of proteins and DNA have been studied using circular dichroism (CD), dynamic light scattering (DLS), gel electrophoresis, protein oxidation test, UV-vis spectroscopy and 1D NMR, while Liquid Chromatograph/Capillary Electrophoresis-Mass Spectrometer(LC/CE-MS) based qualitative bio-analysis have been used to study the modification of amino acids. We have also shown the effect of NaCl and ionic liquid on the formation of OH radicals using electron spin resonance and fluorescence techinques.

• The Journal of Korean Physical Therapy
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• 제9권1호
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• pp.157-166
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• 1997

The purpose of this study was to determine the effects of laser Irradiation on Human plasma $\beta-endorphin$ levels, by treating with low level helium-neon (He-Ne) and Infrared(lR) laser. The Laser was fixed frequency of 2400Hz by continuous scanning and irradiating time was 8 minutes each point. Blood samples were taken at before, after, after 15min's treatment and Plasma $\beta-endorphin$ was measured by radioimmunoassay. The samples for this study were 6 normal subjects(3male, 3female). The data were analyzed by paired t-test, one-way ANOVA and simple regression. The results of this study were as follows : 1. The human plasma $\beta-endorphin$ levels were noted as significant increase in after-treatment $(22.84{\pm}10.63pg/ml)$ as compared with before-treatment $(16.96{\pm}9.23pg/ml)$ and significant increase in after 15min's $(27.27{\pm}8.81pg/ml)$ as compared with after-treatment (p<0.05). 2. There were no significant changes in plasma g-endorphin levels between male and female. 3. The human plasma $\beta-endorphin$ levels were high associated in between session reliability (p<0.05).

• Journal of Nutrition and Health
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• 제31권2호
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• pp.126-134
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• 1998

Our previous study demonstrated that dietary taurine or glycine supplementation significantly lowered plasma and hepatic cholesterol and triglyceride concentrations in rats fed a cholesterol-free diet. In the present study, the effect of long term dietary taurine or glycine supplementation, for the purpose of preventing and/or treating of hyperlipidemia and other known biological functions, on plasma and hepatic free amino acid concentrations and profiles were evaluated in rats. Three groups of male rats(110-130g) were fed a control diet(CD), taurine-supplemented diets(TSD ; CD+ 1.5% taurine) or glycine-supplemented diet(GSD ; CD+1.5% glycine) for 5 weeks. Plasma and hepatic free amino acid concentrations were determined by an automated amino acid analyzer based on ion-exchange chormatography. The feeding of TSD for 5 weeks yielded a 444% higher plasma taurine concentration , and the feeding GSD for the same period resulted in a 143% higher plasma glycine level in rats compared to those fed DB. Hepatic taurine concentration was significantly higher in rats fed TSD(145% increase) compared to the control rats. However, hepatic glycine concentration was not influenced by dietary glycine supplementation , which implies that the massive dose of glycine entering the body was more rapidly metabolized or excreted than taurein. Dietary taurine or glycine supplementation resulted in similar changes in plasma free amino acid concentrations, except in levels of taurine and glycine. Plasma levels of histidine, lysine, phenylalanine , alanine, proline, hydroxypoline, $\alpha$-aminogutyric acid, cystathionine and ethanolamine were significantly higher in rats fed TSD or GSD than those fed GD. Glycine supplementation did not change hepatic free amino acid concentrations as compared to CD. Concentrations of most hepatic free amino acids were not influenced by dietary taurine supplementation with the exception of significantly higher levels of asparate and tyrosine(56-63% increase) and lower levels of histidine and glutamate(33-34% decrease) compared to the control rats. These results suggest long-term dietary taurine or glycine supplementation resulted in increases in most plasma free amino acid levels, but did not cause a characteristic change in plasma aminogram pattern compared to rats fed CD.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.508-513
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• 2000

HANJUNG has developed demonstration plant treating combustion flue gas such as dioxide($SO_2$) and nitrogen oxides(NOx). Before operating this system, we tested the inner airflow characteristic of demonstration plant in the front of plasma reactor field 1 and field 2. The experimental results of $25,000Nm^3/hr$ airflow are compared with the computational results using FLUENT code. It is found that the velocity distribution trends are matched the experimental results with the calculation results. To improve the eccentric airflow in the inlet hood, it is necessary to install the vertical guide vane as well as the horizontal guide vane.