• Journal of Power System Engineering
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• v.22 no.6
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• pp.67-73
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• 2018

Gasoline that meets the quality standards is distributed in Korea. However, consumers who use toluene or solvent mixed with gasoline have appeared due to rising crude oil prices and for the purpose of tax evasion. Gasoline quality standard is enacted by the domestic and international research reference. A wrong fuel can influence automobile performance or environmental issue. Thus, empirical data from this issue is necessary. Therefore, this research observed catalyst influence by gasoline property change and inspect influence of environment. In this study, fuel property evaluation, lean-burn evaluation, and real vehicle exhaust emission test were performed. In the result of fuel property, the fuel "A" was measured to be up to 27% less octane than the normal gasoline and the distillation property was measured 24% higher than normal gasoline. In the test result of single cylinder engine lean-burn test, the fuels "A" and "B" show torque value 20% less than the normal gasoline. As a result of vehicle test using the catalyst, the fuel "A" was increased more than the normal gasoline with 83% THC, 1,806% CO and 128% NOx, and the fuel "B" was increased more than normal gasoline with 1.6% THC, 391% CO and 142% NOx.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.59-62
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• 2019

In this study, we have developed solution-processed, F-doped In-Ga-Zn-O semiconductors and investigated their applications to thin-film transistors. In order for forming the appropriate channel layer, precursor solutions were formulated by dissolving the metal salts in the designated solvent and an additive, ammonium fluoride, was incorporated additionally as a chemical modifier. We have studied thermal and chemical contributions by a thermal annealing and an incorporation of chemical modifier, from which it was revealed that electrical performances of the thin-film transistors comprising the channel layer annealed at a low temperature can be improved significantly along with an addition of ammonium fluoride. As a result, when the 20 mol% fluorine was incorporated into the semiconductor layer, electrical characteristics were accomplished with a field-effect mobility of $1.2cm^2/V{\cdot}sec$ and an $I_{on}/_{off}$ of $7{\times}10^6$.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.80-80
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• 2019

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. It is the world's fourth-largest crop, following rice, wheat, and maize. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Chlorogenic acid constitutes up to 90% of potato natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. Recently, potato 'Seohong' was developed by RDA, and it has reported that they have a high-yield and dry matter content. Processing industry of potato generates high amounts of peel as a byproduct. It was reported as a good source of several beneficial functional ingredients including antioxidant effect. This study was conducted to enhance the utilization of the peel of Potato 'Seohong'. The anti-inflammatory effects on solvent fraction was evaluated. The anti-inflammatory activities of Ethylacetate fraction was evaluated for inhibitory activities against lipopolysacchride (LPS) induced nitric oxide (NO) in RAW264.7 cell lines. The fraction inhibitory activity for tests with $IC_{50}$ values showed in the ranges of $50{\mu}g/ml$. This result revealed that n-butanol fraction of 'Seohong's peel is expected to be good candidate for development into source of anti-inflammatory agent.

• Elastomers and Composites
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• v.39 no.4
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• pp.318-323
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• 2004

Cloud-point and bubble-point curves for poly(ethylene-co-13.8 mol% octene) ($PEO_{13.8}$) and Poly(ethylene-co-15.3 mol% octene) ($PEO_{15.3}$) were determined up to $150^{\circ}C$ and 450 bar in hydrocarbons which have different molecular size and structure. Whereas ($PEO_{15.3}$+ n-pentane) system has cloud-point and bubble-point type transitions, ($PEO_{15.3}$+ n-propane) and ($PEO_{15.3}$+ n-butane) systems do only cloud-point type transition. In cyclo-pentane, -hexane, -heptane, and -octane, $PEO_{15.3}$ has a bubble-point transition. ($PEO_{13.8}$+ n-butane) mixture has a critical mixture concentration at 5 wt% PEO. (PEO + hydrocarbon) mixtures exhibit LCST type behavior. Solubility of PEO increases with hydrocarbon size due to increasing dispersion interaction which is favorable to dissolve PEO.

• Polymer(Korea)
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• v.32 no.5
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• pp.409-414
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• 2008

The fabrication of gelatin nanofibers by electro spinning has been examined using the TFE/DW co-solvent system. It has been found that no beads-on-string structure was formed for the solution containing ionic salts. The resulting fibers exhibited a uniform diameter ranging from 110 to 125 nm. As the concentration of ionic salts increases, the beads become smaller and more spindle like, due to the increase of viscosity and conductivity. The addition of ionic salts induces a higher charge density on the surface of ejected jet during spinning, leading that higher elongation forces are applied to the jet. The higher enhancement of viscosity and conductivity was observed in gelatin solutions by the use of divalent salt. However, the concentration of ionic salts scarcely affected the variation of fiber diameter. While very low crystallinity was observed from XRD pattern for the sample containing no ionic salt, which increased with increasing the concentration of ionic salts.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.3
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• pp.35-44
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• 2007

Purpose: This study was conducted to investigate the anti-proliferative effects of Ulmi Pumilae Cortex Extracts(UPCE) on MCF-7(human, breast, adenocaecinoma) and NIH3T3 (human, murine, fibroblast). Methods: MCF-7 cells and NIH3T3 cells were cultured and seeded in cell culture plates, respectively. UPC was extracted with hot water and then further fractionated it into five types: hexane, chloroform, ethyl acetate, butanol, and water soluable fractions. These five different fractions from UPCE were tested for their anti-proliferative effects on MCF-7 cells and NIH3T3 cells by MMT assay. Results: Among the five solvent-fractions of UPCE, n-hexane fraction and ethyl acetate fraction showed a strong anti-proliferative effects on MCF-7 cells but they displayed significant cytotoxicity on NIH3T3 cells, too. On the other hand, chloroform fraction showed a marked anti-proliferative effects on MCF-7 cells and low cytotoxicity on NIH3T3 cells. Conclusion: Chloloform fraction from UPCE showed selective anti-cancer activities on human breast cancer cell MCF-7 relatively to the other fractions.

• Food Science and Preservation
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• v.18 no.6
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• pp.954-960
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• 2011

The antioxidant activities of the ethanol, methanol, and water extracts of black onion were investigated. The highest extraction yield (28.56%) and total polyphenol content (13.5 mg/g) were found in the water extract. The water extract also showed the highest protective effect on the RAW 264.7 cell anti-inflammatory activity, and the water and ethanol extracts showed the highest reducing power. The water extract showed higher DPPH and ABTS radical scavenging activities (65.98 and 89.69%, respectively) than the other solvent extracts (ethanol, 47.77%; methanol, 66.12%). Hence, black onion can be used as a potent natural antioxidative source.

• Journal of Soil and Groundwater Environment
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• v.19 no.6
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• pp.13-17
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• 2014

Subcritical water acts like an organic solvent at elevated temperature in terms of its physicochemical properties. Taking into account this advantage, the remediation experiments of benzo[a]pyrene contaminated soil (8.45 mg/kg of initial concentration) were conducted using subcritical water extraction apparatus. The effect of operating factors on the removal efficiency was studied at the varying the conditions of the water temperature ranging $200{\sim}300^{\circ}C$, extraction time 30~90 min, and flow rate 0.3~2.0 mL/min. 12 g of benzo[a]pyrene contaminated soil was inserted into the extraction cell and placed into the reactor and then the subcritical water was driven through the cell. In this study, the removal efficiency of benzo[a]pyrene was increased from 55.1 to 98.1% when the temperature increased from 200 to $300^{\circ}C$. The removal efficiency was decreased from 97.0 to 77.0% when the flow rate increased from 0.3 to 2.0 mL/min, suggesting that the extraction is limited by intra-particle diffusion. The 30 min reaction time was determined as an effective treatment time at $250^{\circ}C$. Based on the results, the optimum condition for the remediation of benzo[a]pyrene contaminated soil was suggested to be $250^{\circ}C$, 30 min, and 0.3 mL/min.

• Natural Product Sciences
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• v.27 no.3
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• pp.187-192
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• 2021

Cordycepin is a characteristic bioactive compound of Cordyceps militaris with various beneficial effects. Cordyceps grows on both grains and insects, and the content of cordycepin varies depending on the cultivation conditions. In this study, the effect of culture conditions on the cordycepin content was analyzed and the extraction conditions were optimized. Analysis of cordycepin content in Pupae-Cordyceps found that it was highly affected by temperature in culture conditions. In the case of mycelium, it grows well at 20 and 25 ℃, but not at 30 ℃. However, the content of cordycepin was highest at 30℃ and less at 20 ℃. The fruiting body also showed a similar tendency: growth was 20 ℃ > 25 ℃ > 30 ℃, but the cordycepin content was 30 ℃ > 25 ℃ > 20 ℃. The content of cordycepin decreased after the fruiting bodies were produced. Next, extraction conditions such as solvent and time were optimized for maximum cordycepin content using response surface methodology (RSM). There was a large difference in the content of cordycepin according to the content of ethanol and the extraction temperature. Through RSM, it was confirmed that the optimum condition for extraction of cordycepin was 48.9 ℃ using 49.0% ethanol, and 160.9 mg/g extract could be obtained under this condition. In conclusion, this study suggested the optimized conditions for the cultivation and extraction of Pupae-Cordyceps for maximizing the content of cordycepin, and this may be applied to the discovery of materials using cordycepin.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.43-48
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• 2018

An etchant capable of forming a circuit in an FTO film that can replace ITO, which depends on full imports, was prepared. The etching solution is composed of 1 to 30% by weight of fluoride, 1 to 20% by weight of acid, 0.5 to 5% by weight of surfactant, 5 to 20% by weight of solvent, 0.5 to 10% by weight of corrosion inhibitor and the balance of water. This etchant can be etched using a dry film, thereby reducing the cost, and is free from bubbles and residue of the etchant. The characteristics of the etchant were etched in a time of 2 minute with a 100 nm thick FTO, and the etchant temperature was maintained at $50^{\circ}C$. An undercut of -0.00364% was obtained when put into a 2 minute etching solution. No harmful substances such as Cd, Pb, Hg and Cr components were measured. The use of FTO in Korea where rare earths do not exist can achieve localization and import substitution effect.