• Journal of the Korean institute of surface engineering
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• 제39권6호
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• pp.268-275
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• 2006

In this study, effect of sputtering on the plasma-nitriding substrate and before PVD coating on the microstucture, microhardness, surface roughness and the adhesion strength of CrZrN thin films were investigated. Experimental results showed that this sputtering process not only removed surface compound layer which formed during a plasma nitriding process but also induced an alteration of the surface of plasma nitrided substrate in terms of microhardness distribution, surface roughness. This in turn affected the adhesion strength of PVD coatings. After sputtering, microhardness distribution showed general decrease and the surface roughness became increased slightly. The critical shear stress measured from the scratch test on the CrZrN coatings showed an approximately 1.4 times increase in the adhesion strength through the sputtering prior to the coating and this could be attributed to a complete removal of compound layer from the plasma nitrided surface and to an increase in the surface roughness after sputtering.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.171-178
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• 2000

To evaluate the pharmacokinetic properties and tissue distribution of a newly developed recombinant human erythropoietin (GC-rhEPO), we analyzed the plasma and tissue levels of erythropoietin by an ELISA after intravenous (IV) and subcutaneous (SC) adminstration to the male rats at the doses of 20, 100, 500 or 2,500 unit/kg. After single IV bolus injection of GC-rhEPO, the plasma concentration was rapidly increased and decreased with two phases with half-lives of 13.4 min and 2.94 hours. AUC was increased dose- dependently but plasma half-lives remained constant regardless of GC-rhEPO doses. Following SC administration, the plasma concentration increased slowly with half-life of 9.2 hours and reached peak at 8 hours. Mean residence time and bioavailability were 18.2 hours and 44%, respectively. After single IV dose of 100 unit/kg, tissue GC-rhEPO level was higher in bone marrow and spleen, while the depletion rate was slower in liver and bone marrow, indicating the higher affinity of GC-rhEPO to bone marrow. Taken together, the experimental results indicate that GC-rhEPO contained the typical pharmacokinetic properties and the tissue distribution patterns inherent to human erythropoietin.

• Journal of Welding and Joining
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• 제5권1호
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• pp.23-33
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• 1987

Plasma arc cutting is a fusion cutting process in which a gas constricted arc is employed to produce high temperature, high velocity jet at the workpiece. Even though the plasma arc cutting has been wid¬ely used in the industry, very little work has been done on the analysis of the process. In this paper, the kerf width was numerically analyzed by soving the temperature distribution in base metal under consideration of the latent heat effect. In modelling the heat flow problem, the heat intensity of the plasma arc was assumed to have a Gaussion distribution in the transverse direction and expone¬ntially decreasing in the thickness direction. The thermal efficiency and the heat input ratio of the top surface were experimentally deterimned for various thickness and cutting conditions, and used in numerical calculation of the kerf width. The experimental results were in eonsiderabely good agreement with the theoretically predicted kerf width.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제24권2호
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• pp.89-94
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• 2011

The cause of the thickness non-uniformity in the large area deposition of $SiO_2$ films by PECVD(Plasma Enhanced Chemical Vapor Deposition) was investigated by the plasma diagnostics. The spatial distribution of the plasma species in the chamber was obtained with DLP(Double Langmuir Probe) and the new-designed probe-type QMS(Quadrupole Mass Spectrometer). From the relationship between the spatial distribution of the plasma species and the depositing rate of the $SiO_2$ films, it was conformed that the non-uniform deposition of $SiO_2$ films was related with the spatial distribution of the oxygen radical density and electron temperature.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 학술대회지
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• pp.460-462
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• 2004

The control of the data retention time is a main issue for realizing future high density dynamic random access memory. There are several leakage current mechanisms in which the stored data disappears. The mechanisms of data disappear is as follow, 1 )Junction leakage current between the junction, 2) Junction leakage current from the capacitor node contact, 3)Sub-threshold leakage current if the transfer transistor is affected by gate etch damage etc. In this paper we showed the plasma edge damage effect to find out data retention time effectiveness. First we measured the transistor characteristics of forward and reverse bias. And junction leakage characteristics are measured with/without plasma damage by HP4145. Finally, we showed the comparison TRET with etch damage, damage_cure_RTP and hydrogen_treatment. As a result, hydrogen_treatment is superior than any other method in a curing plasma etch damage side.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제45권3호
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• pp.415-425
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• 1996

This study presents an analytical method of solving the behaviors of arc plasma in a nozzle constricting transferred-type torch and purposes to obtain the basic data for the design of a plasma torch, which can be obtained from the temperature, pressure, velocities and voltage distributions. We have to solve some conservation equations simultaneously and need to know the exact thermal gas properties in order to obtain the correct behaviors of arc plasma. It is also necessary to give the relevant physical or geometric boundary conditions. For the simplicity of analysis, we assumed that (a) the plasma flow is laminar, (b)the local thermodynamic equilibrium, i.e. LTE, prevails over the entire arc column region. The electrode sheath effects were neglected and the nozzle area was excluded from the analysis by assuming that the current flow into the nozzle is zero. We solved the momentum transfer equation including the self-magnetic pinch effect, and obtained the temperature distribution from the energy conservation equation. From this temperature, we could get arc voltage distribution. (author). refs., figs., tabs.

• Journal of the Korean Vacuum Society
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• 제10권2호
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• pp.275-281
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• 2001

We used the discrete-sectional model to analyze the particle growth by coagulation of particles in silane plasma reactor, considering the Gaussian distribution function for particle charges. The effects of process conditions such as monomer size and mass generation rate of monomers on particle growth in plasma reactor were analyzed theoretically/ Based on the Gaussian distribution function of particle charges, the large particles of more than 40 nm in size are almost found to be charged negatively, but some fractions of small, tiny particles are in neutral state or even charged positively. As the particle size and surface area increase with time by particle coagulation, the number of charges per particle increases with time. As the large particles are generated by particle coagulation, the particle size distribution become bimodal. The results of discrete-sectional model for the particle growth in silane plasma reactor were in close agreement with the experimental results by Shiratani et al. [3] for the same plasma conditions. We believe the model equations for the particle charge distribution and coagulation between particles can be applied to understand the nano-sized particle growth in plasma reactor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.582-584
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• 2007

In order to improve the accuracy of simulated results, new UV source was designed. Previously the optical simulation was performed with the symmetric planar UV source. To design new UV source, UV distribution from the plasma fluid code was implanted to the 3-dimensional optical code to generate the visible light distribution. The results from planar UV source and new UV source were compared with the ICCD (Intensified CCD) image in real PDP cell and analyzed the variation of geometries and optical properties.

• The Korean Journal of Physiology
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• 제24권2호
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• pp.331-344
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• 1990

What makes glucose transport function sensitive to insulin in one cell type such as adipocyte, and insensitive in another such as liver cells is unresolved question at this time. Recently it is known that insulin stimulates glucose transport in adipocytes largely by redistributing transporter from the storage pool that is included in a low density microsomal fraction to plasma membrane. Therefore, insulin sensitivity may depend upon the relative distribution of gluscose transporters between the plasma membrane and in an intracellular storage compartment. In hepatocytes, the subcellular distribution of glucose transporter is less well documented. It is thus possible that the apparent insensitivity of the hepatocyte system could be either due to lack of the constitutively maintained, intracellular storage pool of glucose transporter or lack of insulin-mediated transporter translocation mechanism in this cell. In this study, I examined if any intracellular glucose transporter pool exists in hepatocytes and this pool is affected by insulin. The results obtained summarized as followings: 1) Distribution of subcellular fractions of hepatocyte showed that there are $24.9{\pm}1.3%$ of plasma membrane, $36.9{\pm}1.7%$ of nucleus-mitochondria enriched fraction, $23.5{\pm}1.2%$ of lysosomal fraction, $9.6{\pm}1.0%$ of high density microsomal fraction and $4.9{\pm}0.5%$ of low density microsomal fraction. 2) In adipocyte, there were $29.9{\pm}2.6%$ of plasma membrane, $19.4{\pm}1.9%$ of nucleus-mitochondria enriched fraction, $26.7{\pm}1.8%$ of high density microsomal fraction and $23.9{\pm}2.1%$ of low density microsomal fraction. 3) Surface labelling of sodium borohydride revealed that plasma membrane contaminated to lysosomal fraction by $26.8{\pm}2.8%$, high density microsomal fraction by $8.3{\pm}1.3%$ and low density microsomal fraction by $1.7{\pm}0.4%$ respectively. 4) Cytochalasin B bound to all of subcellular fractions with a Kd of $1.0{\times}10^{-6}M$. 5) Photolabelling of cytochalasin B to subcellular fractions occurred on 45 K dalton protein band, a putative glucose transporter and D-glucose inhibited the photolabelling. 6) Insulin didn't affect on the distribution of subcellular fractions and translocation of intracellular glucose transporters of hepatocytes. 7) HEGT reconstituted into hepatocytes was largely associated with plasma membrane and very little was found in low density microsomal fraction which equals to the native glucose transporter distribution. Insulin didn't affect on the distribution of exogeneous glucose transporter in hepatocytes. From the above results it is concluded that insulin insensitivity of hepatocyte may due to lack of intracellular storage pool of glucose transporter and thus intracellular storage pool of glucose transporter is an essential feature of the insulin action.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.209-211
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• 2002

A simple-structured thermal plasma generator for waste gas treatment has been studied. The thermal plasma technology applied to waste treatment has undoubtedly gained high importance owing to its outstanding properties such as flexibility, compact reactor, and clean treatment. Moreover, the thermal plasma generated by ac power has some additional advantages such as simple electrode system and easy maintenance. A prototype 200kW class plasma generator with specifications of 10-30m/sec gas velocity and 3000-5000K temperature on the center just outside of the nozzle has been designed and tested. Case studies on heat transfer, heat flow, velocity distribution, and temperature distribution using a commercial simulation package show lots of flexibility in design. The experimental results from theprototype generator show that the ac thermal plasma is easily controlled by working gas flow once it is ignited. A stabilization condition is discussed with the data from monitoring arc voltage drops with respect to gas flow rate during the test.