• Journal of Industrial Technology
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• v.32 no.A
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• pp.57-64
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• 2012

In order to examine the tailorability of advanced sewage treatment of a separated sewer pipe, we observed the quality of leaked water in a reactor. A2C affiliation and MBR affiliation decreased by over 78% in cases of BOD, COD, and SS. SBR affiliation decreased by 79.1% in a case of T-N. Overall, the efficiency of T-N on the above affiliations was low. SS had the high efficiency in MBR affiliation. In the end, examination of water quality improvement showed that the quality was improved from 20% to 90%; hence, it is expected that this treatment can protect the water resources of the Hongcheon River and makes it easier to use the water of the river.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.772-777
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• 2012

In order to examine the tailorability of advanced sewage treatment of a separated sewer pipe, we observed the quality of leaked water in a reactor. A2C affiliation and MBR affiliation decreased by over 78% in cases of BOD, COD, and SS. SBR affiliation decreased by 79.1% in a case of T-N. Overall, the efficiency of T-N on the above affiliations was low. SS had the high efficiency in MBR affiliation. In the end, examination of water quality improvement showed that the quality was improved from 20% to 90%; hence, it is expected that this treatment can protect the water resources of the Hongcheon River and makes it easier to use the water of the river.

• Toxicological Research
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• v.7 no.2
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• pp.141-149
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• 1991

The treatment with 5ng/ml of mercuric chloride caused time-dependent decreases, and in the activities of GSH S-transferase and GSH-peroxidase, and in the concentration of GSH in CHO cells. Three hours after treatment of $Hg^{2+}$, the activity of GSH S-transferase was decreased to almost half value of control group and the activity of GSH-peroxidase was reduced significantly at 6 hr after treatment. The concentration of GSH was decreased 2 hr after treatment of $Hg^{2+}$ and was decreased to nearly half value of control group 3 hr after treatment.

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.2
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• pp.125-129
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• 2012

Dental treatment under general anesthesia is considered for behavioral control of disabled patients who have severe anxiety or involuntary movement. However, in case of simple treatment, inhalation or intravenous sedation, which has earlier onset and recovery, is preferred. Conventionally, nitric oxide is used for inhalation sedation, nowadays sevoflurane can also be used due to easily titratable for controllable effect and less complications. In this case report, two patients with mental retardation required simple dental treatment. Deep sedation with inhaled sevoflurane were successfully employed and patients were discharged without any complications.

• Journal of the Korean Society for Heat Treatment
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• v.26 no.3
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• pp.126-131
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• 2013

In this study, effects of silicon addition on the spheroidizing annealing of hyper-eutectoid steel was investigated. Heat treatment at various temperatures in the ${\gamma}+{\theta}$ region was also conducted in order to systematically control the kinetics of undissolved cementite. It was found that small amount of Si addition could increase both $A_1$ and $A_{cm}$ transformation temperature by both the JMat Pro evaluation and dilatometric measurement. It was also revealed by the microstructural observation that the volume fraction of retained cementite during heat treatment increased with decreasing temperature as well as increasing Si content. Based on the results obtained, it could be suggested that spheroidization at relatively higher temperature above $950^{\circ}C$ could be achieved by small addition of Si.

• Korean Journal of Materials Research
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• v.18 no.5
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• pp.229-234
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• 2008

Porous Ti implant samples were fabricated by the sintering of spherical Ti powders in a high vacuum furnace. To increase their surface area and biocompatibility, anodic oxidation and a hydrothermal treatment were then applied. Electrolytes in a mixture of glycerophosphate and calcium acetate were used for the anodizing treatment. The resulting oxide layer was found to have precipitated in the phase form of anatase $TiO_2$ and nano-scaled hydroxyapatite on the porous Ti implant surface. The porous Ti implant can be modified via an anodic oxidation method and a hydrothermal treatment for the enhancement of the bioactivity, and current multi-surface treatments can be applied for use in a dental implant system.

• Journal of Korea Foundry Society
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• v.31 no.5
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• pp.262-266
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• 2011

The aim of this study is to investigate aging behavior of A356 alloy for turbo charger part. The specimen was fabricated by investment casting. Solution heat treatment was performed at $525^{\circ}C$ for 8h and followed by aging treated at $160^{\circ}C$, $170^{\circ}C$ for 0.5~20h. And their microstructures and mechanical properties of the aged specimens were analyzed by scanning electron microscope and hardness tester, respectively. All the cast A356 alloy included eutectic Si particles. In the cast A356 alloy, eutectic Si phase mainly was formed along Chinese script phase. Vickers hardness of the cast was improved by aging treatment due to formation of ${\beta}$" phase and ${\beta}$' phase.

• Journal of Korea Foundry Society
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• v.26 no.1
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• pp.17-26
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• 2006

The substitution of cooling method from water quenching to air cooling after solution heat treatment was aimed for the development of a convenient and economical heat treatment process of duplex stainless steels without deterioration of mechanical and corrosion resistant properties for the industry. In order to achieve this goal, the mechanical properties and corrosion properties of a ASTM A890-4A duplex stainless steel were systematically investigated as functions of casting condition and cooling method after solution heat treatment. A 3-stepped sand mold and a permanent Y-block mold were used to check the effects of solidification structure and cooling rate after solution heat treatment. The microstructural characteristics such as the ferrite/austenite phase ratio and the precipitation behavior of ${\sigma}$ phase and carbides were investigated by combined analysis of OM and SEM-EDX with an aid of TTT diagram. Hardness and tension test were performed to evaluate the mechanical properties. Impact property at $-40^{\circ}C$ and corrosion resistance were also examined to check the possibility of the industrial application of this basic study. Throughout this investigation, air-cooling method was proved to effectively substitute for water-quenching process after the solution heat treatment, when the duplex stainless steel was sand mold cast with a thickness below 15 mm or permanent mold cast with a thickness below 20 mm.

• Korean Journal of Materials Research
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• v.33 no.4
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• pp.142-150
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• 2023

AZO/Cu/AZO thin films were deposited on glass by RF magnetron sputtering. The specimens showed the preferred orientation of (0002) AZO and (111) Cu. The Cu crystal sizes increased from about 3.7 nm to about 8.5 nm with increasing Cu thickness, and from about 6.3 nm to about 9.5 nm with increasing heat treatment temperatures. The sizes of AZO crystals were almost independent of the Cu thickness, and increased slightly with heat treatment temperature. The residual stress of AZO after heat treatment also increased compressively from -4.6 GPa to -5.6 GPa with increasing heat treatment temperature. The increase in crystal size resulted from grain growth, and the increase in stress resulted from the decrease in defects that accompanied grain growth, and the thermal stress during cooling from heat treatment temperature to room temperature. From the PL spectra, the decrease in defects during heat treatment resulted in the increased intensity. The electrical resistivities of the 4 nm Cu film were 5.9×10^-4 Ω·cm and about 1.0×10^-4 Ω·cm for thicker Cu films. The resistivity decreased as the temperature of heat treatment increased. As the Cu thickness increased, an increase in carrier concentration resulted, as the fraction of AZO/Cu/AZO metal film increased. And the increase in carrier concentration with increasing heat treatment temperature might result from the diffusion of Cu ions into AZO. Transmittance decreased with increasing Cu thicknesses, and reached a maximum near the 500 nm wavelength after being heat treated at 200 ℃.

• Current Photovoltaic Research
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• v.3 no.2
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• pp.65-70
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• 2015

We applied KF on CIGS film to modify CIGS surface with a wider-bandgap surface layer. With the KF deposition the surface of CIGS film had fine particle on the CIGS surface at 350 and $300^{\circ}C$. No fine particle was detected at 500 and $250^{\circ}C$. With the KF treatment, the Ga and O content increased at the surface, while the In and Cu content decreased. The valence band maximum was lowered with KF treatment. The composition profile and band structure were positive side of applying KF on the CIGS surface. However, the efficiency decreased with the KF treatment due to high series resistance, probably due to too thick surface layer. A smaller amount of KF should be supplied and more systematic analysis is necessary to obtain a reproducible higher efficiency CIGS solar cells.