• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.577-584
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• 1996

Silicon oxide films with high hardness and water repellency were prepared by microwave plasma-enhanced CVD using four kind of organosilicon compound-fluoro-alkyl silane mixtures as source gases. An argon gas was used as a carrier gas for fluoro-alkyl silane. The substrate temperatures during deposition were controlled by resistant heating at a constant value between 50 and $300^{\circ}C$. The hardness of the films increased, but the deposition rate and the contact angle for a water drop decreased with increasing substrate temperature. The number of methoxy groups also affected the water repellency and hardness. The deposited films became more inorganic with increasing substrate temperature because of the thermal dissociation of reactants.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.576-576
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• 2013

Recently, diagnostics of plasma becomes more important due to requirement of precise control of plasma processing based on measurement of plasma characteristics. The Langmuir probe has been used for the diagnostics but it has an inevitable uncertainty and error sources such as incorrect tip length and RF noise. Instead of the Langmuir probe, various diagnostic methods have been developed and researched. The cutoff probe is promising one for plasma density using microwaves and resonance phenomenon at the plasma frequency. The cutoff probe has various advantages as follows; (i) it is simple and robust, (ii) it uses few assumptions, and (iii) it is free from deposition by reactive gas. However, the cutoff probe also has uncertainty and error sources such as gap between tips, tip length, direction of tip plane, and RF noise. In this study, the uncertainty and error sources in manufacturing both probes and in diagnostics process were analyzed via comparative experiment at various discharge conditions. Furthermore, to reveal the user dependence of both probes, three well trained Ph. D students made the Langmuir probe and the cutoff probe, respectively, and it were analyzed. Thought this study, it is established that reliability and validity of the Langmuir probe and the cutoff probe related with not only the intrinsic characteristics of probes but also probe user.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.25-30
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• 2001

Viral safety is a prerequisite for manufacturing clinical albumin and immunoglobulins from human plasma pools. This study was designed to evaluate the efficacy of cold ethanol fractionation and pasteurization (60$\^{C}$ heat treatment for 10h) for the removal/inactivation of human immunodeficiency virus type 1 (HIV-1) during the manufacturing of albumin and immunoglobulins. Samples from the relevant stages of the production process were spiked with HIV-1, and the amount of virus in each fraction was quantified by the 50% tissue culture infectious dose(TCID(sub)50). Both fraction IV fractionation and pasteurization steps during albumin processing were robust and effective in inactivating HIV-1, titers of which were reduced from an initial 8.5 log(sub)10 TCID(sub)50 to undetectable levels. The log reduction factors achieved were $\geq$ 4.5 and $\geq$ 6.5, respectively. In addition, fraction III fractionation and pasteurization during immunoglobulins processing were robust and effective in eliminating HIV-1. HIV-1 titers were reduced from an initial 7.3 log(sub)10 TCID(sub)50 to undetectable levels. The log reduction factors achieved in this case were $\geq$ 4.9 and $\geq$ 5.3, respectively. These results indicate that the process investigated for the production of albumin and immunoglobulins have sufficient HIV-1 reducing capacity to achieve a high margin of safety.

• Journal of the Korean Vacuum Society
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• v.18 no.5
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• pp.337-345
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• 2009

When the drill hole diameter for the package substrate is under $100{\mu}m$, the smear in the drill hole cannot be eliminated by wet desmear process only. We intended to change the substrate's hydrophobic characteristics to hydrophilic characteristics by adapting the atmospheric pressure plasma prior to the wet desmear process. Atmospheric pressure plasma process was made as the inline type equipment which is adequate for the package substrate's manufacturing process and remote DBD type electrodes were used for the equipment. As the result of atmospheric pressure plasma processing, the contact angle of the substrate was enhanced from 71 degree to 30 degree. Dielectric film thickness, drill hole diameter and surface roughness were measured to evaluated the characteristics of the wet desmear process in case of plasma processing and in case of none. By the measurement, it was analyzed that the process uniformity within the whole panel was largely enhanced. Also, it was verified that the smear in the drill hole was eliminated efficiently which was analyzed by the SEM image of the drill hole.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.703-706
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• 2015

The interaction of plasma with liquid generates nitrogen species including nitrite (NO⁻₂). Therefore, the color developing capacity of plasma-treated water (PTW) as a nitrite source for meat curing was investigated in this study. PTW, which is generated by surface dielectric barrier discharge in air, and the increase of plasma treatment time resulted in increase of nitrite concentration in PTW. The PTW used in this study contains 46 ppm nitrite after plasma treatment for 30 min. To evaluate the effect of PTW on the cured meat color, meat batters were prepared under three different conditions (control, non-cured meat batter; PTW, meat batter cured with PTW; Sodium nitrite, meat batter cured with sodium nitrite). The meat batters were vacuum-packaged and cooked in a water-bath at 80℃ for 30 min. The typical color of cured meat developed in cooked meat batter treated with sodium nitrite or PTW. The lightness (L*) and yellowness (b*) values were similar in all conditions, whereas, the redness (a*) values of cooked meat batter with PTW and sodium nitrite (p<0.05) were significantly higher than the control. These data indicate that PTW can be used as a nitrite source in the curing process of meat without addition of other nitrite sources.

• Journal of Powder Materials
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• v.16 no.5
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• pp.358-362
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• 2009

Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ quaternary amorphous alloy was prepared by high-energy ball milling process. A complete amorphization was confirmed for the composition of Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ after milling for 30hrs. Differential scanning calorimetry showed a large super-cooled liquid region ($\Delta$T$_x$ = T$_x$ T$_g$, T$_g$ and T$_x$: glass transition and crystallization onset temperatures, respectively) of 80 K. Prepared amorphous powders of Ti$_{50}$Cu$_{20}$Ni$_{20}$Al$_{10}$ were consolidated by spark-plasma sintering. Densification behavior and microstructure changes were investigated. Samples sintered at higher temperature of 713 K had a nearly full density. With increasing the sintering temperature, the compressive strength increased to fracture strength of 756 MPa in the case of sintering at 733 K, which showed a 'transparticle' fracture. The samples sintered at above 693 K showed the elongation maximum above 2%.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.193-197
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• 2017

In this study, we report on the catalyst process installed in conjunction with a wet plasma electrostatic precipitator to remove the oil mist and fine dust emitted from large-size grill restaurants. The multi-stage catalyst module reduced odor through catalytic reaction of acetaldehyde on catalysts even at an ambient temperature with ozone as an oxidant readily produced in a wet plasma electrostatic precipitator. Two types of manganese-based catalysts, $Mn_2O_3$ and $CuMnO_x$ were fabricated by extrusion molding for structured catalysts in practical applications, and the optimum conditions for high removal efficiencies of acetaldehyde and ozone were determined. When two optimized catalysts were applied in a two-stage catalyst module, the removal efficiency of acetaldehyde and ozone were ${\geq}85%$ and 100% respectively at the space velocity of $10,000h^{-1}$ and the reaction temperature of $100^{\circ}C$.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.681-686
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• 2006

Plasma nitrocarburising and plasma post oxidation were performed to improve the wear and corrosion resistance of S45C and SCM440 steel by a plasma ion nitriding system. Plasma nitrocarburizing was conducted for 3h at $570^{\circ}C$ in the nitrogen, hydrogen and methane atmosphere to produce the ${\varepsilon}-Fe_{2-3}$(N, C) phase. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of $500^{\circ}C$ for 1 hour. The very thin magnetite ($Fe_3O_4$) layer $1-2{\mu}m$ in thickness on top of the $15{\sim}25{\mu}m$ ${\varepsilon}-Fe_{2-3}$(N, C) compound layer was obtained by plasma post oxidation. A salt spray test and electrochemical testing revealed that in the tested 5% NaCl solution, the corrosion characteristics of the nitrocarburized compound layer could be further improved by the application of the superficial magnetite layer. Throttle valve shafts were treated under optimum plasma processing conditions. Accelerated life time test results, using throttle body assembled with shaft treated by plasma nitrocarburising and post oxidation, showed that plasma nitrocarburizing and plasma post oxidation processes could be a viable technology in the very near future which can replace $Cr^{6+}$ plating.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.26-27
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• 2004

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.10a
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• pp.43-43
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• 2003