• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2474-2479
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• 2009

This paper presents an atmospheric microplasma-jet device for bio~medical application. The microplasma-jet device consists of four components; a thin Ni anode, porous alumina insulator, a stainless steel cathode and an aluminum case. The anode has 8 holes, and hole diameter and depth are $200 {\mu}m$ and $60 {\mu}m$, respectively. The discharge test was performed in atmospheric pressure using nitrogen gas and AC voltage at the optimum gas flow rate of 4 Vmin. The plasma-jet is ejected stably for the input voltage ranging from 5.5 to $9.5 kV_{p-p}$. The plasma becomes dense as the input voltage increases, which was verified by the hydrophilicity change of PMMA surface treated by the plasma. The temperature increasement of the aluminum film exposed to plasma-jet illustrates that the micro plasma-jet device is feasible for bio-medical application.

• Journal of the Korean institute of surface engineering
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• v.50 no.6
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• pp.504-509
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• 2017

In order to improve corrosion resistance for cast stainless steel in seawater, the characteristics of corrosion resistance after plasma ion nitriding was investigated. Plasma ion nitriding process was conducted in a mixture of nitrogen of 25% and hydrogen of 75% at substrate temperature ranging from 350 to $500^{\circ}C$ for 10 hours using pulsed-DC glow discharge plasma with working pressure of 250 Pa in vacuum condition. Corrosion tests were carried out for as-received and plasma ion nitrided specimens. The corrosion characteristics were investigated by measurement of weight loss and observation of surface morphology. In anodic polarization experiment, relatively less damage depth and weight loss were presented at a nitrided temperature of $400^{\circ}C$, attributing to the formation of S-phase.

• Textile Coloration and Finishing
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• v.8 no.3
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• pp.59-65
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• 1996

Cotton fabrics were treated by low temperature plasma and/or cellulase, and its physical and dyeing properties were investigated. All the pretreatments of the cotton with low temperature plasma of oxygen, nitrogen and argon slowed down the rate of weight loss of cotton in cellulase solution. Plasma pretreatment did not show any strength retention effect on cotton fiber in the subsequent cellulase treatment. Pretreatment of cotton with low temperature oxygen plasma decreased the rate of dyeing in direct dye bath, while cellulase or plasma/cellulase pretreatment increased the rate. Equilibrium dye uptake of cotton was not changed greatly by the pretreatments except the normal untreated cotton showed more or less high uptake. The pretreatment of cellulase with a water-soluble carbodiimide reduced the enzymatic activity, and did not show any strength retention of cotton in enzymatic weight loss.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.159-159
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• 2013

In this studying, we investigated the basic properties of N-doped plasma polymer. The N-doped plasma polymer thin films were deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition method. Various carbon-source were used as organic precursor with hydrogen gas as the precursor bubbler gas. Additionally, ammonia gas [NH3] was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using cyclic voltammetry, ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, Raman spectroscopy, FE-SEM, and water contact angle measurement. Electronic property of N-doped plasma thin film is changed as flow rate of the NH3 gas.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.1010-1018
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• 2006

A glucose clamp technique was used to investigate the effects of non-protein energy intake on tissue responsiveness and sensitivity to insulin for glucose metabolism in intact adults male goats. Three goats were fed diets at 1.0, 1.5 and 2.0 times of ME for maintenance, each for 21 d. Crude protein intake was 1.5 times of maintenance requirement in each treatment. Tissue responsiveness and sensitivity to insulin were evaluated using a hyperinsulinemic euglycemic clamp technique with four levels of insulin infusion, beginning at 13 h after feeding. Concentrations of plasma metabolites and insulin were also measured at 3, 6 and 13 h after feeding, for evaluating effects of non-protein energy intake on the metabolic status of the animals. Increasing non-protein energy intake prevented an increase in plasma NEFA concentration at 13 h after feeding (p = 0.03). Plasma urea-nitrogen and total amino-nitrogen concentrations decreased (p<0.01) and increased (p = 0.03), respectively, with increasing non-protein energy intake across time relating to feeding. Plasma insulin concentration was unaffected (p = 0.43) by non-protein energy intake regardless of time relating to feeding. In the glucose clamp experiment, increasing non-protein energy intake decreased numerically (p = 0.12) the plasma insulin concentration at half-maximal glucose infusion rate (insulin sensitivity), but did not affect (p = 0.60) maximal glucose infusion rate (tissue responsiveness to insulin). The present results suggest that an increase in non-protein energy intake may enhance insulin sensitivity for glucose metabolism, unlike responsiveness to insulin, in adult male goats. The possible enhancement in insulin sensitivity may play a role in establishing anabolic status in the body, when excess energy is supplied to the body.

• Journal of Adhesion and Interface
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• v.8 no.4
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• pp.23-31
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• 2007

An atmospheric plasma pre-treatment method was applied to EVA foam, Leather (Action), Rubber and Unwoven to improve its contact angle and adhesion using atmospheric plate type reactor. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen), rate of gas flow (30~100 mL/min), and reaction time (0~30 sec) were examined in a plate plasma reactor. The result of the surface modification with respect to the treatment procedure was characterized by using SEM. Due to a decrease of the contact angle of various materials, the greatest adhesion strength was achieved at optimum condition such as flow rate of 100 mL/min, reaction time of 10 second for an atmosphere nitrogen gas. Consequently, the atmospheric plasma treatment reduced the contact angle of the EVA foam, Leather (Action) and Rubber also resulted in the improvement of the adhesion.

• Polymer(Korea)
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• v.32 no.5
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• pp.433-439
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• 2008

An atmospheric plasma pre-treatment method was applied to polyurethane foam (density: 0.27) and rubber (butadiene rubber) to improve its contact angle and adhesion using atmospheric plate type reactor. In order to investigate the optimum reaction condition of plasma treatment, type of treatment gas (nitrogen, argon, oxygen, air), rate of gas flow ($30{\sim}100\;mL/min$), and treated time ($0{\sim}30\;s$) were examined in a plate plasma reactor. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of various materials, the greatest adhesion strength was achieved at optimum condition such as flow rate of 100 mL/min, reaction time of polyurethane foam 10 s and rubber 3 s for an atmosphere nitrogen gas. Consequently, the atmospheric plasma treatment reduced the wettability of the polyurethane foam and rubber also resulted in the improvement of the adhesion.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.435-438
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• 2004

MOCVD is one of the major deposition techniques for Cu thin films and Ta-Si-N is one of promising barrier metal candidates for Cu with high thermal stability. Effects of hydrogen plasma pretreatment of the underlying Ta-Si-N film surface on the Cu nucleation in Cu MOCVD were investigated using scanning electron microscopy, X-ray photoelectron spectroscopy and Auger electron emission spectrometry analyses. Cu nucleation in MOCVD is enhanced as the rf-power and the plasma exposure time are increased in the hydrogen plasma pretreatment. The optimal plasma treatment process condition is the rf-power of 40 Wand the plasma exposure time of 2 min. The hydrogen gas flow rate in the hydrogen plasma pretreatment process does not affect Cu nucleation much. The mechanism through which Cu nucleation is enhanced by the hydrogen plasma pretreatment of the Ta-Si-N film surface is that the nitrogen and oxygen atoms at the Ta-Si-N film surface are effectively removed by the plasma treatment. Consequently the chemical composition was changed from Ta-Si-N(O) into Ta-Si at the Ta-Si-N film surface, which is favorable for Cu nucleation.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.510-515
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• 2001

It was first time that low frequency R.F. derived plasma enhanced MOCVD with frimethylborate precursor was used to fabricate a new ternary compound $BO_{x}$ $N_{y}$ . The formation of BON molecule was resulted from nitrogen nitrifying B-O, and forming the angular molecule structure proved by XPS and FT-IR results. The relationship between hardness and film thickness was studied. An thickness-independent hardness was fond about 10 GPa. The empirical calculation of band-gap and UV test result showed that our deposited $BO_{x}$ $N_{y}$ thin film was semiconductor material with 3.4eV of wide band gap. The electrical conductivity, $4.8$\times$10^{-2}$ /($\Omega$.cm)$^{-1}$ also confirmed that $BO_{x}$ $N_{y}$ has a semiconductor property. The roughness detected from the as-grown films showed that there was no serious bombarding effect due to anion in the plasma occurring in the RF frequency derived plasma.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.8
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• pp.401-408
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• 2001

The information of the ion composition in plasma applications is required to characterize a plasma. A better understanding of ion species composition ratio and its spacial distribution, etc. is thus necessary in plasma-related processes, such as thin film deposition, plasma-based ion implantation, semiconductor processing, and so on. In this research, a compact ion mass analyzer that is based on magnetic sector analyzer was developed and its operational characteristics were studied in nitrogen plasma.