• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.234-238
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• 2016

Solid ash-free coal (AFC) samples recovered from solvent-extracted solution by vacuum drying, dilution precipitation and spray drying methods were compared in terms of physical properties and chemical structure. AFC was prepared by using Kideco coal (Indonesian sub-bituminous coal) and polar N-methyl-2-pyrrolidone (NMP) solvent as raw materials. The physical properties of the AFCs were characterized with proximate, ultimate, and calorific value analysis. In analyzing the chemical structure, FTIR and NMR were used. the proximate analysis showed much reduced ash in the AFCs compared to parent raw coal. The FTIR result showed that the extraction solvent was not fully removed from the AFC prepared by vacuum drying. However, the solvent was not detected in the AFC recovered by using dilution precipitation. Dilution precipitation has advantages over the other two methods, since it can be done at relatively low temperature and separate ash-free coal from extraction solvent more effectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.424.1-424.1
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• 2016

태양전지 모듈의 봉지재로 사용되는 EVA(Ethylene-Vinyl acetate)는 외부의 환경으로부터 태양전지를 보호해주는 역할을 한다. 하지만 frame의 실링재나 glass edge 부분의 결함으로 인해 수분이 침투되어 모듈의 내부자재에 영향을 미치게 되며, 모듈의 효율 감소나 수명 단축의 원인이 된다. 이러한 결함을 줄이기 위해서는 EVA의 crosslinking degree, 절연 저항 특성을 향상시키는 것이 중요하다. 이에 본 연구에서는 EVA의 crosslinking degree를 보기 위해 soxhlet extraction method를 이용하여 gel content를 측정하였으며, 라미네이션 과정 중 curing time에 따른 gel content 변화를 확인하였다. 또한 이 실험을 바탕으로 gel content에 따른 절연 저항을 측정하여 EVA의 crosslinking degree에 의한 절연 저항 특성을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.319.1-319.1
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• 2014

We present the results on the indium tin oxide (ITO) Schottky barrier solar cells (SBSCs) with InAs quantum dots (QDs). The dependence of external quantum efficiency on the external bias voltage has been studied to anlayze carrier extraction through tunneling at room temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.12
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• pp.1002-1009
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• 2011

The light extraction efficiency of top-emitting organic light-emitting diode (OLED) was improved by insertion of corrugation patterns between indium tin oxide and organic layers. The corrugation patterns was fabricated by nanosphere lithography, which could form a self-assembled particle monolayer over a large area. The electrical and optical properties for the OLED devices fabricated by vacuum evaporation, were investigated. We have demonstrated the enhancement of the power efficiency of corrugated OLED. As a result, the power efficiency of the corrugated OLED was found to be more than 42%.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.1-8
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• 1996

The component analysis of wax for detecting temperature in automobile thermostat of the automotive engine and manufacture of it with distillation and solvent extraction were progressed. From the lift test results of prepared samples, it was found that the solvent extracted samples were in the proper range for use as an automobile thermostat of the automotive engine. And more accurate wax could be manufactured by high vacuum fractional distillation and acid treatment after solvent extraction from crude oil pitch.

• Applied Biological Chemistry
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• v.23 no.2
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• pp.106-114
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• 1980

The flavor constituents of Korean Milgam were extracted with a nitrogen gas stream under partial vacuum and identified by gas liquid chromatography. By employing the extraction coefficient, it was possible to determine the concentration of components in Milgam as well as in the extracts. Among 53 GLC peaks, 26 components were identified. Ethanol was the most abundant component (140ppm), followed by limonene (120ppm). These two were the most important flavor constituents.

• Journal of Ginseng Research
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• v.6 no.2
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• pp.115-122
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• 1982

This studies were conducted to investigate the effect of extraction and evaporating conditions on the free sugar in ginseng extracts. Raw ginseng roots were extracted with water or various concentration of water-ethanol solutions. Then the extracts were evaporated by boiling or vacuum evaporated at 50 $^{\circ}C$ and 70 $^{\circ}C$. The results are as follows Sucrose and maltose contents were 7.95% and 12.8% in water extracts and 19.96%, 0.34-0.93% in 90% ethanol extracts, respectively. On the otherhand, glucose and fructose contents were not affected by the solvents. Evaporating conditions, such as temperature, were rarely effected to the sugar contents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.574-584
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• 1998

Antimicrobial activities, extraction yields and chemical compositions of the extract from the powder of vacuum dried Smilax china root on various solvents were investigated. Antimicrobial activities against. A rhizogenes, A. tumefaciens, C. utilis, S. cerevisiae, B. megaterium, B. subtilis and E. coli were measured by disc diffusion method. Methanol, chloroform, ethylacetate and butanol extracts exhibited potent antimicrobial activities against B. megaterium and B. subtilis. Also, methanol, ethylacetate and butanol extracts had the activities against A. rhizogenes, and chloroform and ethylacetate extracts against A. tumefacciens. The extraction yields were 13.10%, 8.71%, 2.73%, 0.83%, 0.54% and chemical compositions of their extracts were very different according to the kinds of solvents. The main chemical groups of ethylacetate, methanol, chloroform and butanol extracts were 45.99% phenolics, 36.10% acids, 29.13% phenolics and 18.96% phenolics, respectively.

• Journal of the Korean Chemical Society
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• v.8 no.2
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• pp.75-77
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• 1964

It was confirmed that korean scabby barley during the summer of 1963 was infected with Gibberella zeae. Feeding experiments showed that the diseased grain was toxic and induced emesis in pigs. The concentrated extracts which contained the emetic principle were prepared by refluxing the grain with methanol or water for 5 hours and then concentrating the filtrates and the washing in vacuum. Animal tests proved that methanol extraction for the emetic principle was more effective than extraction with water.

• Tribology and Lubricants
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• v.1 no.1
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• pp.59-68
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• 1985

Processes such as vacuum distillation, mixed solvent extraction, neutralization and clay treatment were used to refine an electrical insulating oil, The improved reused oil showed an excellent copper corrosion resistance and gave a better oder than that of oil refined from the conventional acid treatment method.