• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1003-1012
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• 2018

This study is for checking the possibility of Lentinula edodes as cosmetic materials. For this we carried out biological active evaluation about anti-oxidant and anti-inflammatory effects by Lentinula edodes extracts. We extracted Lentinula edodes with water and 70% ethanol and then in order to evaluate anti-oxidant activity we treated samples by concentrations (100, 500, 1000) ${\mu}g/ml$ and carried out 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, the activity of 2,2'-azino-bis ( 3-ethylbenzothiazoline-6-sulphonic acid )-diammonium salt (ABTS) cation radical scavenging and superoxide dismutase(SOD) like activity. Also, in order to evaluate effect of anti-inflammatory the samples in macrophages(RAW 264.7 cells), we carried out evaluation of cell viability, nitric oxide inhibitory activity western blot. The results of DPPH, $ABTS^+$ radical scavenging activity and SOD-like activity of the Lentinula edodes extracts increased in dose-dependent manner. The cytotoxic of samples by MTT assay showed no toxicity at the concentrations of 10, 25 and $50{\mu}g/ml$ of Lentinula edodes extract. Nitric oxide inhibition activity results showed that the extracts reduced NO productions in a concentration-dependent manner. Expression of inflammatory cytokines as $TNF-{\alpha}$, $PGE_2$ and $IL-1{\beta}$ decreased in a concentration-dependent manner and iNOS and COX-2 proteins expression rates were decreased significantly in western blot analysis. From the results of the experiment, it was comfirmed that the Lentinula edodes extracts had excellent anti-oxidant and anti-inflammatory effect and could be used as a safe natural cosmetic material in the future.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.2
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• pp.69-74
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• 2007

[ $0.6Pb(Sc_{1/2}Ta_{1/2})O_3-0.4PbTiO_3$ ] (hereafter PSTT) ceramics were prepared by the molten salt synthesis (MSS) method using KCI as a flux. Formation of perovskite phase was investigated by a differential thermal analysis (DTA) and X-ray diffraction (XRD) analysis in the temperature range from $600^{\circ}C$ to $850^{\circ}C$. A 92% perovskite phase was synthesized at $750^{\circ}C$ for 2 hrs using the MSS method, while 82% perovskite phase was synthesized at $850^{\circ}C$ for 4ks using the calcining of mixed oxide (CMO) method. This result could be due to the improvement in reactivity of $Sc_2O_3$ by melting of KCI. The MSS specimen sintered at $1,100^{\circ}C$ for 4hrs showed a dielectric constant of 11,200, a remnant polarization of $13.5{\mu}C/cm^2$ and a coercive field of 10.198 kV/cm, which was discussed in view of the microstructure.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.48-67
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• 2013

This study was focused on the recognition of historical values and the establishment of conservation schemes for a Silla stone monument in Bongpyeong-ri, Uljin by combining the humanistic investigation of inscription reinterpretation and the scientific conservational diagnosis of deterioration. According to the investigation of inscription, a total of 13 letters were reconsidered compared to the preceding researches. Thus, the meaning and interpretation of previous inscription was partially changed. This monument is composed of gneissose leucogranite and the most suitable site as provenance of the stone would be the Jukbyeon seashore (2.1km). The site shows similar color, size and composition of minerals, gneissose structure and magnetic susceptibility as the Bongpyeong stone monument. This monument developed a structural crack (crack index 0.4) and a microcrack (crack index 2.0) along the gneissose structure. The horizontal strength is weaker than the vertical strength. Therefore, the cracks should be reinforced and treated. However, consolidating is not urgently needed because the total weathering grade by ultrasonic velocity shows the stage of moderate weathering(3,403m/s, 0.32). Also, the major problems of chemical deterioration are blackening (85.2%) with soil, iron oxide,rubbing mark, and salt crystals (17.3%) from the sea. Therefore, the contaminants and the salt crystals should be removed using pressure spray and pulp paper, while the application of poultice should be examined through clinical tests.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.10
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• pp.940-948
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• 2007

The Advanced Spent Fuel Conditioning Process(ACP), which is the process of the reduction of uranium oxide by lithium metal in a high temperature molten salt bath for spent fuel, was developed at Korea Atomic Energy Research Institute (KAERI). Since the ACP equipment is located in an intense radiation field (hot cell) as well as in a high temperature, it must be remotely operated and maintained. The ACP hot cell is very narrow so the workspace of the wall-mounted mechanical Master-Slave Manipulators(MSMs) is restricted. A Bridge Transported Servo Manipulator(BTSM) system has been developed to overcome the limitation of an access that is a drawback of the mechanical MSMs. The BTSM system consists ot a bridge crane with telescoping tubeset, a slave manipulator, a master manipulator, and a control system. We applied a bilateral position-position control scheme with friction compensation as force-reflecting controller. In this paper, the transmission characteristics on the tendon-and-pulley train is numerically formulated and analyzed. Also, we evaluate the performance of the force-reflecting servo manipulator.

• Journal of Powder Materials
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• v.16 no.1
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• pp.43-49
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• 2009

Titanium carbides are widely used for cutting tools and grinding wheels, because of their superior physical properties such as high melting temperature, high hardness, high wear resistance, good thermal conductivity and excellent thermal shock resistance. The common synthesizing method for the titanium carbide powders is carbo-thermal reduction from the mixtures of titanium oxide($TiO_2$) and carbon black. The purpose of the present research is to fabricate nano TiC powders using titanium salt and titanium hydride by the mechanochemical process(MCP). The initial elements used in this experiment are liquid $TiCl_4$(99.9%), $TiH_2$(99.9%) and active carbon(<$32{\mu}m$, 99.9%). Mg powders were added to the $TiCl_4$ solution in order to induce the reaction with Cl-. The weight ratios of the carbon and Mg powders were theoretically calculated. The TiC and $MgCl_2$ powders were milled in the planetary milling jar for 10 hours. The 40 nm TiC powders were fabricated by wet milling for 4 hours from the $TiCl_4$+C+Mg solution, and 300 nm TiC particles were obtained by using titanium hydride.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.79-84
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• 1999

the photolithographic patterning on an indium-tin oxide (ITO) glass and the electro-phoretic deposition were combined for preparing the screen of the full-color field emission display(FED). the patterns with a pixel of 400$\mu\textrm{m}$ on the ITO-glass were made by etching the ITO with well-prepared etchant consisting of HCL, H2O, and HNO3. Electrophoretic method was carried out in order to deposit each spherical red (R), green(G), and blue (B) phosphor on the patterned ITO-glass. The process parameters such as bias voltage, salt concentration, and deposition time were optimized to achieve clear boundaries. It was found that the etching process of ITO combined with electrophoretic method was cost-effective, provided distinct pattern, and even reduced process steps compared with conventional processes. The application of reverse bias to the dormant electrodes while depositing the phosphors on the stripe pattern was found to be very critical for preventing the cross-contamination of each phosphor in a pixel.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.32-37
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• 2006

In this study, we have purified and characterized the membrane bound nitrate reductase obtained from the denitrifying bacteria, Ochrobactrum anthropi SY509, which was isolated from soil samples. O. anthropi SY509 can grow in minimal medium using nitrate as a nitrogen source. We achieved an overall purification rate of 15-fold from the protein extracted from the membrane fraction, with a recovery of approximately 12% of activity. The enzyme exhibited its highest level of activity at pH 5.5, and the activity was increased up to $70^{\circ}C$. Periplasmic and cytochromic proteins, including nitrite and nitrous oxide reductase, were excluded during centrifugation and were verified using enzyme essay. Reduced methyl viologen was determined to be the most efficient electron donor among a variety of anionic and cationic dyestuffs, which could be also used as an electron donor with dimethyl dithionite. The effects of purification and storage conditions on the stability of enzyme were also investigated. The activity of the membranebound nitrate reductase was stably maintained for over 2 weeks in solution. To maintain the stability of enzyme, the cell was disrupted using sonication at low temperatures, and enzyme was extracted by hot water without any surfactant. The purified enzyme was stored in solution with no salt to prevent any significant losses in activity levels.

• Corrosion Science and Technology
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• v.15 no.5
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• pp.209-216
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• 2016

In the present study, chitosan based self-healing anticorrosion coatings were prepared by layer by layer (lbl) addition of chitosan (Ch) and polyvinyl butyral (PVB) on mild carbon steel substrate. Chitosan coatings exhibited enhanced coating stability and corrosion resistance in aggressive environments by the application of a PVB top layer. Chitosan layer in the lbl coatings have been modified by using glutaraldehyde (Glu) and silica ($SiO_2$). Performance of different coatings was tested using electrochemical impedance spectroscopy and immersion test. The best anticorrosion performance was observed in case of 10 % Ch_$SiO_2$_PVB coatings, which withstand immersion test over 25 days in 0.5 M salt solution without visible corrosion. 10 % Ch_$SiO_2$ coatings without the PVB top layer didn't last more than 3days. Application of PVB top layer sealed the defects in the chitosan pre-layer and improved its hydrophobic nature as well. Raman spectra and SEM of steel surfaces after corrosion study and removal of PVB_Ch/Glu_PVB coatings showed a passive layer of iron oxide, attributing to the self-healing nature of these coatings. Conducting particle like graphene reinforcement of chitosan in the lbl coatings enhanced corrosion resistance of chitosan coatings.

• Membrane Journal
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• v.26 no.5
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• pp.351-364
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• 2016

In recent decades, many researchers have tried to improve desalination performances of polyamide (PA) thin-film composite membranes (TFCs) by incorporating nanomaterials into a selective PA layer. This review focuses on PA-based nanocomposite membranes with high performances for energy-effective desalination in reverse osmosis. Carbon based nanomaterial (e.g., graphene oxide (GO), carbon nanotubes (CNT)) and/or other nanoparticles (e.g., zeolite, silica and etc.,) were applied to overcome the trade-off correlation between water permeability and salt rejection of current polymeric desalination membranes. Here, this brief review will discuss current studies of PA-based nanocomposite membranes with enhanced separation characteristics and provide the future research direction to achieve further improved desalination performances.

• Macromolecular Research
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• v.16 no.2
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• pp.169-177
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• 2008

This paper reports a facile synthesis of new water-soluble poly(ethylene oxide) (PEO)-based amphiphilic block copolymers showing pH sensitive phase transition behaviors. The copolymers were prepared by atom transfer radical polymerization (ATRP) of methacrylamide type of monomers carrying a sulfonamide group using a PEO-based macroinitiator and a Cu(I)Br/$Me_6TREN$ catalytic system in aqueous media. The resulting polymers were characterized by a combination of $^1H$-NMR, size exclusion chromatography, and UV/Visible spectrophotometeric analysis. The micellization of the block copolymers as a drug-loading mechanism in aqueous media using fluorescein salt was examined as a function of pH. The stable micelle formation and its loading efficacy suggest that the block copolymers can be used as precursors for drug-nanocontainers.