• Plant Resources
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• 제8권3호
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• pp.263-274
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• 2005

We have studied the effects of dampening papers (Dampened paper, Newspaper, Korean paper, Flower sheet), silica gel (30g, 60g) and temperature ($20^{\circ}C,\;25^{\circ}C$) on color changes of Erythronium japonicum. In the treatment of $20^{\circ}C$, color changes were low in treatments with silica gel rather than in a treatment of dampening papers. In particular, newspaper and Korean paper showed much less changes in colors by the combination treatments with 30g of silica gel. Likewise, in the treatment of $25^{\circ}C$, color changes were low in combination treatments with silica gel rather than in a alone treatment of dampening papers. For the combination treatment with 30g of silica gel, low color changes were shown in the divisions of newspaper and Korean paper, while for the combination treatment with 60g of silica gel, low color changes were shown in the those of Korean paper and dampened paper.

• 약학회지
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• 제35권6호
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• pp.461-465
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• 1991

Silica-based gel filtration chromatography has been used to characterize molecular weight of proteins. However, the molecular weight measured by this method was distorted by protein-silica interactions like hydrophobic and electrostatic forces. Therefore, we characterized protein-silica interaction using two forms of phytochrome (124 kDa) having different hydrophobicity and surface charge. PH and ionic strength affected the retention time of phytochrome suggesting that electrostatic force is the major interaction between protein and silica surface.

• Bulletin of the Korean Chemical Society
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• 제6권2호
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• pp.112-115
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• 1985

3-Aminopropylsilated silica gel bound hemin, biliverdin, and bilirubin were synthesized by reacting 3-aminopropyl silated silica gel with hemin, biliverdin and bilirubin respectively. The aspects of binding of bilirubin to amino group of 3-aminopropylsilated silica gel were studied using the above synthetic silica immobilized hemin, biliverdin and bilirubin, and oxodipyrromethene.

• 한국세라믹학회지
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• 제33권12호
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• pp.1394-1402
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• 1996

The Silica gel with the density of 0.2g/cm3 and porosity of 90% was synthesized. The silica wet gel was dried and heat-treated under the ambient pressure after modification of the wet gel surface by TMCS. Specific surface area total pore volume and mean pore radius of dried gel were all increased with increasing heat treatment temperature and confirmed about 1400m2/g, 4.5cc/g and 8 nm respectively after heat treatment above 25$0^{\circ}C$. But the pore size distribution of dried gel was in the range of 1-100nm and was almost indepen-dent of temperature. As the result of external shape pore characteristics and microstructure of gel using SEM similar properties were observed between the silica gel synthesized in this study and the silica aerogel through the super critical drying.

• 멤브레인
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• 제11권3호
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• pp.124-132
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• 2001

고온에서 수소 분리 회수를 목적으로 silica/alumina 복합 막을 합성하였다. 막의 선택 투과 성능을 향상시키기 위해, sol-gel법에 의한 silica 및 alumina층을 중간층으로 도입하고, 그 위에 강제유동 CVD법에 의한 silica를 합성하였다. Sol-gel법에 의해 ${\alpha}$-alumina tube에 합성한 ${\gamma}$-alumina 및 silica 막은 Knudsen 확산 영역의 많은 mesopore를 포함하고 있어서 수소 선택 분리 막으로는 적합하지 못했다. 하지만, sol-gel법에 의해 합성한 silica/${\gamma}$-alumina층에 강제유동 CVD법으로 silica를 합성한 결과, 질소 투과 영역의 세공이 완전히 제거되어, 높은 수소 선택성을 가지는 복합 막이 형성되었다. 그 막은 온도에 따라 수소 투과 속도가 증가하여 $450^{\circ}C$에서 $5.57{\times}10^{-8}molm^2s^LPa^1$의 수소 투과 속도와, 9.52 kJ/mol의 활성화 에너지를 나타냈다. 분자체 효과에 의해 질소 투과가 완전히 배제되고, 수소만 선택적으로 투과되는 silica/alumina 복합막이 성공적으로 합성된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.232-233
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• 2006

In recent years the interest in organic/inorganic hybrid materials has increased at a fast rate. Nano organic-inorganic hybrid composites have shown advantages for preparing hard coating layers. Especially, nano hybrid composite has low environmental pollution. It has high transparency, hardness, toughness, thermal dissociation temperature, hydrophobicity by using nano sized inorganic material. There are many ways in which these materials may be synthesized, a typical one being the use of silica and silanes using the sol-gel process. The structure of sol-gel silica evolves as a result of these successive hydrolysis and condensation reactions and the subsequent drying and curing. The sol-gel reactions are catalyzed by acids and produce silica sol solutions. The silica sol grows until they reach a size where a gel transition occurs and a solid-like gel is formed. Colloidal silica(CS)/silane sol solutions were synthesized in variation with parameters such as different acidity and reaction time. In order to understand their physical and chemical properties, sol-gel coating films were fabricated on glass. From all sol-gel solutions, seasoning effect of sol-gel coating layer on glass was observed.

• 한국세라믹학회지
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• 제29권5호
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• pp.357-366
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• 1992

Residual organics were considered as impurity in Sol-Gel method. The purpose of this study was to find the conditions to contain as much residual organics as possible in silica gel prepared from TEOS(tetraethylortho-silicate) by Sol-Gel method. Residual organics are to be expected to have reduction effect on synthesizing Si3N4 from silica gel. The results of this study are follows: 1) The maximum content of entrapped carbon was 19.8 wt.%(C/SiO2=0.25 wt.ratio) in silica gel synthesized under the conditions 1.5 fold mole water for incomplete hydrolysis, 2.5 fold mole phenol as a solvent and 0.1 fold mole HCl as a catalyst to TEOS. 2) Silica gel with organics entrapped by Sol-Gel method had a positive effect on the formation of Si3N4 compared with commercial silica gel. 3) Sintered body of synthesized $\alpha$-Si3N4 with Y2O3 and Al2O3 as additives at 175$0^{\circ}C$ in N2 atmosphere showed bending strength, 602$\pm$20 MPa and frature toughness 4.45$\pm$0.15 MPa.m1/2.

• 한국응용과학기술학회지
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• 제34권4호
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• pp.954-961
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• 2017

재조합 ${\beta}$-galactosidase (${\beta}$-gal)을 이용하여 transgalactosylation 반응으로 합성된 2-phenoxyethanol galactoside (PE-gal)과 chlorphenesin galactoside (CPN-gal)의 정제를 실시하였다. 먼저 PE와 PE-gal이 포함된 반응물에 ethyl acetate (EA)를 넣고, EA/water 이상계 시스템에서 PE와 PE-gal을 분획하였다. 이 시스템에서 PE는 EA층으로 PE-gal은 water층으로 분획되었다. 그리고, 물층을 모아서 silica gel chromatography를 실시하였다. 최종적으로, silica gel chromatography만 실시하여 PE-gal을 정제한 경우와, EA 처리 후 silica gel chromatography를 실시하여 PE-gal을 정제한 경우의 정제 PE-gal에 대하여 HPLC (High performance liquid chromatography)와 TLC (thin-layer chromatography) 분석을 수행하였다. 그 결과 EA를 처리하여 분획한 후, silica gel chromatography를 수행한 시료에서 잔여 PE가 완전히 제거되는 것을 관찰하였고, silica gel chromatography만 실시하여 PE-gal을 정제한 경우에는 상당량의 잔여 PE가 관찰되었다. 이 때, mole 기준으로 약 21%의 정제 수율을 확인할 수 있었다. 마찬가지로 CPN-gal의 정제에서도 EA 분획 처리 후, silica gel chromatography를 수행하였더니, 잔여 CPN이 거의 없는 순수한 CPN-gal을 얻을 수 있었다.

• 동력기계공학회지
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• 제15권4호
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• pp.75-78
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• 2011

There are various types of materials used in electronic industry, such as electrode material, conductor, insulator, anode, cathode and semiconductor. Electrode material type is Cu, Ti, ZnO and so on. Especially if we use mixed ZnO in soil cement or silica gel, we can have advantages in ice road to prevent freezing. We have great impact if we use supported in inorganic substances like silica gel. In this paper we have studied that ZnO supported silica gel and its properties. Zinc acetate dissolved in distilled water were loaded on the silica gel by the reaction with ammonia at $80^{\circ}C$. And we investigated particle structures of ZnO by scanning electron microscopy(SEM) and X-ray diffraction(XRD).

• 한국세라믹학회지
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• 제26권5호
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• pp.677-681
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• 1989

On the preparation of silica glass by sol-gel process, we used fine powder of silica gel to prevent cracking. In this case, the best condition of silica glass preparation is the contents of 10~40wt% seed and the gelation time of solution in contract. The dried gels conversed to silica glass by heat treatment up to 125$0^{\circ}C$.