• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.210-214
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• 2001

GlcNAc 2-epimerase gene from human was cloned. However GIcNAc 2-epimerase was expressed in E. coli as inclusion body formation. Several approaches were tried such as expression in low temperature and low concentration of IPTG. With these treatments production of active form of human GIcNAc 2-epimerase ι ,vas enhanced. For the direct synthesis of NeuAc from GlcNAc and pyruvate, NALase and GlcNAc 2-epimerase were characterized in terms of temperature effect on activity. equilibrium and stability, inhibition by pyruvate etc. For cheap and ease preparation of both the NALase and GlcNAc 2-epimerase, pEN24ma vector was made. which express both the NALasc and GIcNAc 2-epimerase simultaneously. In addition, E. coli BL21(DE3) harboring two plasmids was also made. Of the two systems, the latter was better for the expression of both enzymes.

• Journal of the Korean Wood Science and Technology
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• v.21 no.1
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• pp.51-58
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• 1993

The phenol resorcinol formaldehyde resin (PRF) adhesives which are curing at ambient temperature for structural purposes were synthesized. A PRF resin is produced according to the two-stage reaction system. In first stage, a low-condensed resol or methylolated phenol were prepared from phenol by reaction with a formaldehyde in alkaline condition. The molar ratio of phenol to formaldehyde was 1.0~1.4. And in second-stage, resorcinol was added to combine with the methylol group of a low-condensed resol(R/P molar ratio 0.3). The glue-joint strength, pot-life and workability of this synthetic PRF resin were superior to conventional ambient temperature setting adhesives such as oilic urethane or water based polymer-isocyanate resin for wood adhesives.

• Journal of Integrative Natural Science
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• v.3 no.3
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• pp.157-161
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• 2010

New low temperature synthesis of germanium nanoparticles obtained from the reaction of germanium tetrachloride and sodium/benzophenonewere developed. These germanium nanoparticles terminated with chloride group were oxidized in air to give hydroxy-terminated germanium nanoparticles. Germanium nanoparticle containing 20(S)-camptothecin (CPT) for a noble drug delivery system were developed. FT-IR spectroscopy was used for the characterization of vibrational absorption for the germanium nanoparticle and oxidized germanium nanoparticles containing camptothecin. Electronic absorption and fluorescence properties were measured with UV-Vis and fluorescence spectrometer. The morphology of oxidized germanium nanoparticles containing camptothecin was investigated by using TEM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1022-1025
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• 2003

본 연구에서는 저온 동시 합성법을 이용하여 ITO 나노 분말을 제조하였다. 저온 동시 합성법은 기존의 염화 인듐 및 염화 주석 염이 아닌 인듐 및 주석 유기물 염들을 사용하므로 기존의 $600{\sim}700^{\circ}C$가 아닌 $300^{\circ}C$ 이하에서 공정이 가능하고, 이로써 초미세급의 나노 분말을 얻을 수 있다. 또한 두가지 유기물 염을 동시에 산화시킴으로써 한번에 동시 합성이 가능하다. 이러한 저온 동시 합성법으로 제조한 나노 분말을 분석한 결과 분말의 크기는 평균 5 nm, 비 표면적은 약 $104m^2/g$ 이었다. 또한 EDS 및 XRD 분석 결과 분말의 결정상은 $In_2O_3$ 격자 내에 $3{\sim}8%$의 Sn이 고용된 [222], [400], [440]의 입방정 구조인 고품질의 ITO 나노 분말을 제조할 수 있었다.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.88.1-88
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• 2002

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.402-409
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• 2013

The objective of this study was to develop a synthesis process for ${\beta}$-SiC powders to reduce the synthesis temperature and to control the particle size and to prevent particle agglomeration of the synthesized ${\beta}$-SiC powders. A phenol resin and TEOS were used as the starting materials for the carbon and Si sources, respectively. $SiO_2$-C hybrid precursors with various C/Si mole ratios were fabricated using a conventional sol-gel process. ${\beta}$-SiC powders were synthesized by a carbothermal reduction process using $SiO_2$-C hybrid precursors with various C/Si mole ratios (1.6 ~ 2.5) fabricated using a sol-gel process. In this study, the effects of excess carbon and the addition of Si powders to the $SiO_2$-C hybrid precursor on the synthesis temperature and particle size of ${\beta}$-SiC were examined. It was found that the addition of metallic Si powders to the $SiO_2$/C hybrid precursor with excess carbon reduced the synthesis temperature of the ${\beta}$-SiC powders to as low as $1300^{\circ}C$. The synthesis temperature for ${\beta}$-SiC appeared to be reduced with an increase of the C/Si mole ratio in the $SiO_2$-C hybrid precursor by a direct carburization reaction between Si and excess carbon.

• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.224-229
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• 2018

OPC production requires high calorific value and emits a large amount of $CO_2$ through decarbonation of limestone, accounting for about 7% of $CO_2$ emissions. To reduce $CO_2$ emissions during the Ordinary Portland Cement (OPC) production process, there is a method of reducing the consumption of cement or lower temperature calcination for OPC product. In this study, for energy consumption reduction, we prepared Hauyne-belite cement by calcination at a low temperature compared to that used for OPC and studied the early hydration properties of the synthesized Hauyne-belite cement. We set the ratios of Hauyne and belite to 8 : 2, 5 : 5 and 3 : 7. For the hydration properties of the synthesized Hauyne-belite cement, we tested heat of hydration of paste and the compressive strength of mortar, using XRD and SEM for analysis of hydrates. As for our results, the temperature for optimum synthesis of Hauyne-belite is $1,250^{\circ}C$. Compressive strength of synthesized Hauyne-belite cement is lower than that of OPC, but it is confirmed that compressive strength of synthesized Hauyne-belite cement with mixing in of some other materials can be similar to that of OPC.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.373-376
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• 2009

CdTe thin films for photovoltaic cell devices were deposited on the glass substrates by solution-based deposition methods, at low temperature processing conditions. In order to characterize physical, optical, and electronic properties of CdTe light absorbing polycrystalline material, a series of analysis was carried out in this study.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.149-149
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• 1996

• Proceedings of the Korean Vacuum Society Conference
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• 2001.02a
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• pp.49-49
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• 2001