• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.430-436
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• 1996

We have grown superconducting thin films on various substrates using a pulsed laser deposition (PLD) method. $YBa_2Cu_3O_7-\delta$ (YBCO) superconducting thin films with the superconducting transition temperature ($T_{c. offset}$) of 87K were grown on Si substrates using yittria-stabilized zirconia (YSZ) and $CeO_2$ double buffer layers. We have developed a large area pulsed laser deposition system. The system was designed to deposit up to 6 different materials on a large area substrate up to 7.5cm in diameter without breaking a vacuum. The preliminary runs of the deposition of YBCO superconducting thin films on $SrTiO_3$ substrate using this system showed a very uniform thickness profile over the entire substrate holder area. $T_{c}$ of the deposited YBCO thin film, however, was scattered depending on the position and the highest value was 85K.

• Journal of Life Science
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• v.28 no.3
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• pp.345-350
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• 2018

This study examines the role of six species of microalgae, including Phaeodacylum tricrnutum (PT), Chaetoceros gracilis (CG), Nanochloris oculata (NO), Pavlova lutheri (PL), Chlorella ellipsoidae (CE), and Scendedemus obliquus (SO), on hair loss prevention and scalp improvement. To determine the effects of microalgae extracts on hair loss prevention and scalp improvement, antioxidant activity, cell proliferation in HaCaT cells and HFDPC cells, and the inhibition level of 5-alpha reductase activity were examined. In the study of antioxidant activity, the $EC_{50}$ values of DPPH anti-radical activities indicated that the SO, CG, and ST9 treatment groups demonstrate significant antioxidant activity. In the study of the hydroxyl radical scavenging activity, CG (6.6~42.1%), ST9 (26.0~44.0%), and SO (7.8~44.3%) demonstrated significant effects. Furthermore, SO promoted the proliferation of HaCaT cells and a human epidermal cell line during a 6-day treatment. In the study of the proliferation of HFDPC cells, a hair follicle dermal papilla cell line, CG, and SO significantly stimulated cell proliferation. Finally, PT, CG, and SO significantly inhibited 5-alpha reductase activity. These results suggest that among the six microalgae used in this study, CG and SO have antioxidant effects, induce cell proliferation, inhibit 5-alpha reductase activity, and can be used for hair loss prevention and scalp improvement.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.733-739
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• 2014

To develop an effective use for poor-quality individually quick-frozen (IQF) oysters Crassostrea gigas stored for a long period, the extract conditions, quality characteristics, and optimum reaction flavoring (RF) conditions of a complex extract from these IQF oysters were investigated. The moisture, pH, and volatile basic nitrogen contents of IQF oysters stored for 18 months (18M-IQFO) were 77.9%, 6.32, and 17.9 mg/100 g, respectively. Three different kinds of extract were prepared from 18M-IQFO: a hot-water extract (HE), scrap enzymatic hydrolysate (EH), and complex extract (CE). The respective extracts contained 5.5, 8.6, and 6.6% crude protein and 281.7, 366.0, and 343.0 mg/100 g amino nitrogen, and had 811, 359, and 1,170 mL/kg extraction yields. The CE was superior to the traditional HE in terms of the extraction yield, amino-nitrogen content, and organoleptic qualities, except for the odor. To improve flavor via the Maillard reaction, the reaction system used to produce a desirable flavor comprised CE (Brix $30^{\circ}$), 0.4 M glucose, 0.4 M glycine, and 0.4 M cysteine solution (4:2:1:1, v/v). The reaction time and pH were the independent variables, and the sensory scores for baked potato odor, masking shellfish odor, and boiled meat odor were the dependent variables. The surface response methodology (RSM) analysis of the multiple responses optimization gave a reaction time of 120.6 minutes and pH 7.33 at $120^{\circ}C$. The reaction improved the flavor of CE considerably, as compared to that of the unreacted extract.

• Journal of the Korean Electrochemical Society
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• v.14 no.3
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• pp.176-183
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• 2011

The electrochemical characteristics from various particle sizes of $Ce_{0.9}Gd_{0.1}O_{2-{\delta}}$ (CGO91) in composite cathode comprised of the samarium-strontium doped layered perovskite ($SmBa_{0.5}Sr_{0.5}Co_2O_{5+{\delta}}$) and CGO91 have been investigated for possible application as a cathode material for an intermediate temperature-operating solid oxide fuel cell (IT-SOFC). The area specific resistances (ASRs) of composite cathodes with CGO91 having smaller particle size ($0.4\sim42{\mu}m$) and SBSCO of 1 : 1 ratio (50wt% SBSCO and 50 wt% CGO91, SBSCO: 50) give the lowest ASR of $0.10{\mu}cm^2$ at $600^{\circ}C$ and $0.013{\Omega}cm^2$ at $700^{\circ}C$. However, composite cathodes with having relatively bigger CGO91 particle size show the two times higher ASR results than those of SBSCO : 50. From the 10 times thermal cycles in SBSCO : 50, the ASRs of SBSCO : 50 increased from $0.0193{\Omega}cm^2$ to $0.094{\Omega}cm^2$ at $700^{\circ}C$, however, the ASR value was maintained after 7 times of thermal cycling.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.318-322
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• 2010

NaZSM 5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as the source for cerium. There TGA results shows decomposition of nitrate at $200^{\circ}C$. The ceria impregnated ZSM 5 materials were designated as NaZSM 5 (X) where X is the percent ceria impregnated (3, 5, 7, 11, 19%). They were characterized by XRD, SEM, EDAX, BET techniques. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is evident for 11 and 19% loading. The surface area and pore volume decreased with increase in ceria loading. The maximum adsorption capacity of NaZSM 5 (5%) is 100.2 mg/g of sorbent. The ceria impregnated NaZSM 5's were found to be regenerable, selective and recyclable.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.79-87
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• 1997

A study on the processing method of anchovy hydrolysate paste (AHP) was carried out to improve the sensory quality of salted and fermented fish. Homogenized whole anchovy was hydrolyzed using commercial pretenses, Complex enzyme-2000 (CE, Pacific Chem. Co.) and Alcalase (AL, Novo), in a cylindrical vessel with 4 baffle plates and 6-bladed turbine impeller. Optimal pH, temperature, and enzyme concentration for the hydrolysis with CE and AL were $7.0,\;52^{\circ}C,\;7\%$, and $8.0,\;60^{\circ}C,\;6\%$, respectively. The rational amount of water for homogenization, agitation speed, and hydrolyzing time were $100\%\;(w/w)$, 100 rpm, and 210 min, respectively. To make the hydrolysate to paste type, it was effective to mix the additives, such as starch, soybean protein, agar, and carrageenan gum to the hydrolysate 5 min before the end of boiling at $100^{\circ}C$ for 30 min. Minimal NaCl concentration for long-term preservation was $15\%$, and this could be reduced to $12\%$ by adding $5\%$ of KCl. yield of the AHP based on the total nitrogen content was $94.6\~97.0\%,\;and\;86.0\~89.2\%$, of the nitrogen was amino nitrogen. Salinity, pH and histamine content of the AHP prepared with $12\%$ NaCl and $5\%$ KCl were $9.3\~9.9\%,\;6.1\~6.2$, and below 13 mg/100 g, respectively. The AHP was stable at $26{\pm}3^{\circ}C$ for 60 days on bacterial growth, and addition of $0.05\%$ of rosemary (Herbalox) extract was effective to inhibit the lipid oxidation of the AHP during storage.

• Clinical Endoscopy
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• v.57 no.2
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• pp.237-245
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• 2024

Background/Aims: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) using Franseen needles is reportedly useful for its high diagnostic yield. This study compared the diagnostic yield and puncturing ability of EUS-TA using 22-gauge cobalt-chromium (CO-Cr) needles with those of stainless-steel Franseen needles in patients with solid pancreatic lesions. Methods: Outcomes were compared between the 22-gauge Co-Cr Franseen needle (December 2019 to November 2020; group C) and stainless-steel needle (November 2020 to May 2022; group S). Results: A total of 155 patients (group C, 75; group S, 80) were eligible. The diagnostic accuracy was 92.0% in group C and 96.3% in group S with no significant intergroup differences (p=0.32). The rate of change in the operator (from training fellows to experts) was 20.0% (15/75) in group C and 7.5% (6/80) in group S. Stainless-steel Franseen needles showed less inter-operator difference than Co-Cr needles (p=0.03). Conclusions: Both Co-Cr and stainless-steel Franseen needles showed high diagnostic ability. Stainless-steel Franseen needles are soft and flexible; therefore, the range of puncture angles can be widely adjusted, making them suitable for training fellows to complete the procedure.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.3
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• pp.247-254
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• 2014

The synthesis of Fischer-Tropsch oil is the catalytic hydrogenation of CO to give a range of products, which can be used for the production of high-quality diesel fuel, gasoline and linear chemicals. Our cobalt based catalyst was prepared Co/alumina, silica and titania by the incipient wet impregnation of the nitrates of cobalt and promoter with supports. Cobalt catalysts was calcined at $350^{\circ}C$ before being loaded into the FT reactors. After the reduction of catalyst has been carried out under $450^{\circ}C$ for 24hrs, FT reaction of the catalyst has been carried out at GHSV of 4,000/hr under $200^{\circ}C$ and 20atm. From these test results, we have obtained the results as following ; in case of 12wt% Co-supported $Al_2O_3$, $SiO_2$ and $TiO_2$ catalysts, maximum activities of the catalysts were appeared at the promoters of Mn, Mo and Ce respectively. The activity of 12wt% $Co/Al_2O_3$ added a Mn promoter was about 3 times as high as that of 12wt% $Co/Al_2O_3$ catalyst without promoters. When it has been the experiment at the range of reaction temperature of $200{\sim}220^{\circ}C$ and GHSV of 1,546~5,000/hr, the results have shown generally increasing the activities with the increase of reaction temperature and GHSV.

• Nuclear Engineering and Technology
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• v.52 no.1
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• pp.109-114
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• 2020

This work presents the results of laboratory scale tests of the CARBOFLUOREX (CARBOnate FLUORide EXtraction) process - a novel technology for the recovery of U and Pu from the solid fluorides residue (fluorination ash) of Fluoride Volatility Method (FVM) reprocessing of spent nuclear fuel (SNF). To study the oxidative leaching of U from the fluorination ash (FA) by Na₂CO₃ or Na₂CO₃-H₂O₂ solutions followed by solvent extraction by methyltrioctylammonium carbonate in toluene and purification of U from the fission products (FPs) impurities we used a surrogate of FA consisting of UF₄ or UO₂F₂, and FPs fluorides with stable isotopes of Ce, Zr, Sr, Ba, Cs, Fe, Cr, Ni, La, Nd, Pr, Sm. Purification factors of U from impurities at the solvent extraction refining stage reached the values of 10⁴-10⁵, and up to 10⁶ upon the completion of the processing cycle. Obtained results showed a high efficiency of the CARBOFLUOREX process for recovery and separating of U from FPs contained in FA, which allows completing of the FVM cycle with recovery of U and Pu from hardly processed FA.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.782-787
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• 2008

Ni-ceria cermets have been extensively investigated as candidates for the anode in intermediate-temperature solid oxide fuel cells. We have used the citric method to synthesize nanocomposite powders consisting of NiO (Ni metal content: $40{\sim}60%$ by volume) highly dispersed in $Ce_{0.9}Gd_{0.1}O_{1.95}$ (CGO). The microstructure characteristics and sintering behaviors of the nanocomposites were investigated. No impurity phases were observed and the shrinkage of these substrates matched well with that of a CGO electrolyte with a specific surface area of $11\;m^2/g$. Densification of the CGO electrolyte layer to $<5\;{\mu}m$ thickness was achieved by co-firing the laminated electrolyte with the porous NiO-CGO substrate at $1400^{\circ}C$ for 6 h.