• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.397-402
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• 1999

The base pressure of the vacuum vessel of KSTAR tokamak is to be ultra high vacuum, $10^{-6}\sim10^{-7}Pa$, to produce a clean plasma with low impurity concentrations. For this purpose, vessel and plasma facing components need to be baked up to $250^{\circ}C$, $350^{\circ}C$ respectively to remove impurities from the plasma-material interaction surfaces. Here the required heating power to be supplied for baking has been calculated according to pre-assumed different temperature profiles (baking scenario and proper baking plan for KSTAR tokamak has been proposed. Mass flow rate and temperature of nitrogen gas for baking has also been calculated.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.57-62
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• 2022

The plasma resistance of multi-component glasses containing La, Gd, Ti, Zn, Y, Zr, Nb, and Ta was analyzed in this study. The plasma etching was performed via inductively coupled plasma-reactive ion etching (ICP-RIE) using CF₄/O₂/Ar mixed gas. After the reaction, the glass with a low fluoride sublimation temperature and high content of P, Si, and Ti elements showed a high etching rate. On the other hand, the glass containing a high fluoride sublimation temperature component such as Ca, La, Gd, Y, and Zr exhibited high plasma resistance because the etch rate was lower than that of sapphire. Glass with low plasma resistance increased surface roughness after etching or nanoholes were formed on the surface, but glass with high plasma resistance showed little change in surface microstructure. Thus, the results of this study demonstrate the potential for the development of plasma-resistant glasses (PRGs) with other compositions besides alumino-silicate glasses, which are conventionally referred to as plasma-resistant glasses.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.954-964
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• 2021

Mirror carp Cyprinus carpio nudus (weight 42.0±3.8 g, length 14.3±0.4 cm) were exposed to different concentrations of waterborne copper (0, 100, 200, 400, 800, and 1,600 ㎍ Cu²⁺·L^-1) at 20.3℃ for 96 h. The lethal concentration 50 of waterborne copper was 1,176.45 ㎍ Cu²⁺·L^-1. Among hematological parameters, red blood cell count was significantly decreased, whereas there were no significant changes in the hemoglobin concentration and hematocrit value. Among the inorganic plasma components, calcium was significantly decreased following copper exposure. Conversely, organic plasma components such as glucose and total protein were significantly increased. Similarly, enzymatic components, such as aspartate transaminase, alanine transaminase, and alkaline phosphatase, were also significantly increased. These findings suggest that the copper exposure is detrimental to the survival rates and physiology of C. carpio nudus.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.40-46
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• 2020

Hybrid grouper(Epinephelus fuscoguttatus ♀×E. lanceolatus ♂) (mean weight 25.7±3.5g, mean length 11.2±0.9cm) were exposed to different ammonia concentrations of 0, 5, 10, 20, and 40mg L^-1 for 96 hours. The hematological hematocrit and hemoglobin parameters of the hybrid grouper were significantly decreased by 20 mg L^-1 ammonia exposure. In the organic plasma components, calcium was significantly decreased, whereas there was no change in magnesium. In the organic plasma components, the glucose and cholesterol values of the hybrid grouper were significantly increased by ammonia exposure. In the enzymatic plasma components, the ALP(Alkaline phosphatase) value of the hybrid grouper was also significantly increased by ammonia exposure. The results of this study demonstrate that acute ammonia exposure to hybrid grouper induced changes in hematological parameters and plasma components. Therefore, acute ammonia exposure over 20 mg L^-1 appears to be toxic to hybrid grouper and the results can be used as a major indicator in breeding hybrid grouper.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.187-195
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• 2022

Crucian carp, Carassius carassius (Weight 28.1±3.7 g, Length 10.0±1.0 cm) were challenged with Aeromonas hydrophila at 0, 2.0×10⁴, 2.0×10⁵, 2.0×10⁶, 2.0×10⁷ CFU/ml for 2 weeks. The lethal concentration 50 (LC₅₀) at 2 weeks of C. carassius challenged with A. hydrophila was 19.776×10⁵ CFU/ml. In hematological parameters, the hemoglobin and RBC counts were significantly decreased by A. hydrophila challenge, whereas there was no significant change in hematocrit. The inorganic plasma components such as magnesium and calcium were significantly decreased. In organic plasma components, glucose and cholesterol were significantly increased by A. hydrophila challenge, whereas total protein was significantly decreased. In enzymatic plasma components, ALP (Alkaline phosphatase) were significantly increased by A. hydrophila challenge. The results of this study suggest that the A. hydrophila challenge to C. carassius induced the significant physiological changes in the hematological parameters and plasma components as deadly pathogenic bacteria.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.150-159
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• 2023

To determine the toxic effects of the mirror carp, Cyprinus carpio nudus on waterborne nitric acid exposure, they were exposed to waterborne nitric acid at 0, 4, 20, 100, 500, and 2,500 mg NO₃^-/L for 96 h. The semi-lethal concentration (LC₅₀) of the scented fish by 96 hours of acute exposure to nitric acid was 1,433.54 mg NO₃^-/L. The physiological changes of waterborne nitric acid exposure on mirror carp were evaluated through hematologic properties, and RBC count showed a significantly decreased (p < 0.05). The change in the ion control ability of the mirror carp according to exposure to waterborne nitric acid was evaluated through the plasma inorganic component, and calcium and magnesium were significantly decreased (p < 0.05) in the plasma inorganic component. The health and stress status of the mirror carp due to exposure to waterborne nitric acid were evaluated through plasma organic ingredients, and the plasma organic component glucose showed a significantly increase (p < 0.05). Changes in liver damage and enzyme activity due to waterborne nitric acid exposure were evaluated through plasma enzyme components, the enzymatic activities of plasma AST, ALT, and ALP were significantly decreased (p < 0.05) in high levels of waterborne nitric acid exposure. The results of the present study suggest that waterborne nitric acid exposure to C. carpio nudus can toxicly affect survival, hematologic properties, and plasma components.

• Journal of fish pathology
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• v.28 no.2
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• pp.87-92
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• 2015

Juvenile Paralichthys olivaceus (mean length $17.3{\pm}2.2cm$, mean weight $46.5{\pm}6.3g$) were exposed for 10 days to tributyltin (TBT) at various concentrations (0, 1, 2, 4 and $8{\mu}g/L$). Hematological parameters, such as red blood cell (RBC) count, hematocrit (Ht), and hemoglobin (Hb) concentration, were considerably decreased by high TBT concentrations. In plasma constituents, inorganic components such calcium and magnesium were also significantly altered. Plasma calcium was notably decreased, whereas plasma magnesium was increased. The enzyme components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT), were significantly decreased by TBT exposure. The present findings suggest that TBT exposure can cause significant alterations in hematological parameters and plasma constituents of flatfish Paralichthys olivaceus.

• 연구논문집
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• s.25
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• pp.193-205
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• 1995

Plasma spray coating technology is essential for the microsemiconductor processes based on the electronic and computer industry, and extend gradually the range of application for up-to-date industry such as diesel engine and gas turbine components. These thechonoogies may be applied to the components requiring wear-resistance, heat resistance, fatigue-resistance, and corrosion-resistance. In this research, plasma spray technology was selected for the wear resistant coatings as the most proper technique. The final goal of this study is to improve the wear resistance through establishment of coating soft-ware, and basic research for industrialization of the technology concerned.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1217-1223
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• 2011

In this paper, the dielectric barrier discharge plasma generator has been studied for producing of the high concentration ozone gas. Proposed plasma generator has the structure of extremely narrow discharge air gap(0.15mm) in order to realize the high electric field discharge. We investigate the performance of the dielectric barrier discharge plasma generator experimentally and the results show that the generator has very high ozone concentration characteristics of 13.7[wt%/$O_2$] at the oxygen flow rate of 1[${\ell}$/min] of each discharge cell. So, we confirmed that the proposed plasma generator is suitable for the high concentration ozone production facility of the eco-friendly ozone functional water cleaning system in the electronic components cleaning process.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.363-368
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• 2012

The influence of plasma discharge on the nutrient components ($NO_3$-N, $NH_4$-N, $PO_4$-P, K, Ca, and Mg) and water quality [pH, ORP (oxidation-reduction potential) and electric conductivity] of hydroponic water were investigated. It was observed that the $NH_4$-N, $PO_4$-P, K, Ca, and Mg were kept at the constant concentrations for plasma discharging of 90 min. On the other hand, $NO_3$-N concentration was increased with proceeding of the plasma discharge. The increase of $NO_3$-N concentration was considered with the fact that nitric acid was created from nitrogen among supplying air for the insulation of inside of dielectric barrier. ORP and electric conductivity was increased with plasma discharging time. However, pH was decrease with what because of the generation of the nitric acid. When adjusting the hydroponic ingredients, pH and conductivity must to be considered because of the change of pH and conductivitiy with the discharging.