• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.168-169
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• 1995

• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.221-224
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• 2000

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.69-73
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• 2003

The atmospheric pressure plasma is regarded as an effective method for surface treatments because it can reduce the period of process and doesn't need expensive vacuum apparatus. The performance of non-transferred plasma torches is significantly depended on jet flow characteristics out of the nozzle. In order to produce the high performance of a torch, the maximum discharge velocity near an annular gap in the torch should be maintained. Also, the compulsory swirl is being produced to gain the shape that can concentrate the plasma at the center of gas flow. In this work, the distribution of gas flow that goes out to atmosphere through a plenum chamber and nozzle is analyzed to evaluate the performance of atmospheric pressure plasma torch which can present the optimum design of the torch. Numerical analysis is carried out with various angles of an inlet flow velocity. Especially, three-dimensional model of the torch is investigated to estimate swirl effect. We also investigate the stabilization of plasma distribution. For analyzing the swirl in the plenum chamber and the flow distribution, FVM (finite volume method) and SIMPLE algorithm are used for solving the governing equations. The standard k-model is used for simulating the turbulence.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.7
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• pp.315-318
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• 2005

The effect of plasma cleaning was examined on package delamination phenomena in the integrated circuit (IC) packaging process. Without plasma cleaning, delamination was observed for all three experimental treatments applied after the packaging step, which include bake of If, reflow, and bake of If followed by reflow However, no delamination was observed when the plasma cleaning was performed before and after the wire bonding step. Plasma cleaning was found to be a critical step to improve the reliability of the package by reducing the possibility of contact failure between die pad and bonding wire.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.4
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• pp.513-516
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• 1994

The effects of the prevention of micelle formation and bile acid reabsorption, by using cholestyramine (CHOLN), a bile acid binding polymer, on the plasma lipid of Single Comb White Leghorn male chicks given diets containing medium chain triacylglycerol (MCT) and long chain triacylglycerol (LCT) were investigated. Corn oil and glyceryl tricaprylate were used as LCT and MCT sources, respectively. Plasma HDL cholesterol was reduced by CHOLN in all treatments. Plasma LDL cholesterol was reduced by CHOLN in chicks given LCT diet but not in MCT diet which could be accounted to the reduced plasma total cholesterol in LCT diet with CHOLN. It is concluded that bile acid binding does not alter the cholesteremic effect of MCT in the plasma of chicks.

• Fibers and Polymers
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• v.2 no.1
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• pp.152-156
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• 2001

Three different silicone polymer systems, such as aminofunctional, epoxyfunctional, and hydrophilic epoxyfunctional silicone polymers, were applied onto plasma pretreated wool fabric to improve the dimensional properties. The results showed that the plasma pretreatment modified the cuticle surface of the wool fiber and increased the reactivity of wool fabric toward silicone polymers. Felting shrinkage of plasma and silicone treated wool fabric was decreased with different level depending on the applied polymer system. Fabric tear strength and hand were adversely affected by plasma treatment, but these properties were favorably restored on polymer application. Therefore, it has been concluded that the combination of plasma and silicone treatments can achieve the improved dimensional stability, and better performance properties of wool fabric. The surface smoothness appearances of treated fabrics were measured using a new evaluation system, which showed good correspondence with the results of KES-FB4 surface tester.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.164-165
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• 2007

The effect of hydrogen and oxygen plasma treatments on the structural properties of carbon nanotubes (CNTs) has been systematically investigated. The plasma treatment resulted in the removal of the amorphous carbon particles. As the plasma treatment time was longer, the CNT diameter was reduced, regardless of gas types. Especially, for the sample treated in hydrogen plasma, the catalyst metal on the tip of CNTs was eliminated.

• Toxicological Research
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• v.13 no.3
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• pp.223-228
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• 1997

Quinones have been reported to undergo nonenzymatic reaction with thiols to generate reactive oxygens. It is therefore possible that the nonenzymatic reaction of quinones with thiols in plasma could lead to potentJared cellular toxicity or disease. When 1 mM menadione was added in plasma under pH 11.2, 7.4 and 5.0, the increase in oxygen consumption rate was the order of pH 11.2 > pH 7.4 > pH 5.0. In addition, oxygen consumption rates under plasma anticoagulated with trisodium citrate solution (pH 7.85) was significantly higher than those with acid-citrate-dextrose solution (pH 6.87). SOD and catalase reduced the rate of oxygen consumption induced by menadione in plasma. Taken together, these results suggest that the menadione-induced increased oxygen consumption was due to nonenzymatic reaction of menadione with thiols in the plasma. The presence of plasma has an additive effect on the increased oxygen consumption rates induced by the menadione treatments on our model tissue, platelets, as compared between washed platelet (WP) and platelet rich plasma (PRP). Cytotoxicity, as determined by LDH release, are well correlated with the oxygen consumption rates observed in each system and strongly suggest that menadione-induced cytotoxicity can be increased with the presence of blood plasma.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.1
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• pp.24-28
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• 2005

New post plasma nitriding can achieve a high uniformity that have been difficult in DC nitriding and have a high productivity comparable to gas nitriding. However, it has not a enough high nitriding potential for a rapid nitriding, because surface activation or ion etching in the general plasma nitriding cannot be expected. Thus, in this study, the effects of pre-treatments with oxidation and reduction gas have been investigated to improve the nitriding kinetics of post plasma nitriding. An effective pre-treatment consisting of oxidation and reduction resulted in the increase of surface energy of STD 11. This induced the surface hardness and the effective nitriding depth of STD 11. It is thought that the increase of the surface energy and the surface area with pre-treatment promote the nucleation of nitriding layer.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.384.2-384.2
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• 2014

We investigated the electrical and structural properties of chemical vapor deposition (CVD)-grown graphene and post treated by O2 plasma. For the patterning of graphene, the plasma technology is generally used and essential for etching of graphene. But, the cautious O2 plasma treatments are required to avoid the damage in graphene edge which can be the harmful effects on the device performance. To analyze the effects of plasma treatment on structural properties of graphene, the change of surface morphology of graphene are measured by scanning electron microscope and atomic force microscope before and after plasma treatment. In addition, the binding energy of carbon and oxygen are measured through to X-ray photoelectron spectroscopy. After plasma treatment, the severe changes of surface morphology and binding energy of carbon and oxygen were observed which effects on the change of sheet resistance. Finally, to analyze of graphene characteristics, we measured the Raman spectroscopy. The measured results showed that the plasma treatment makes the upward of D-peak and downward of G'-peak by elevated power of plasma.