• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.55-58
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• 2010

Aliphatic and aromatic nitro compounds were selectively reduced to their corresponding amino derivatives in good yields using formic acid and CeY zeolite under monomode reactor. This system is found to be compatible with several sensitive functionalities. Beside the recycling result showed it had a long catalyst lifetime and could maintain activity even after being used for 20 cycles.

• Journal of the Korean GEO-environmental Society
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• v.16 no.3
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• pp.35-39
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• 2015

Continuous adsorption and recovery characteristics for gold and lead-cyanide complexes in industrial wastewater were investigated by the Dowex 21K XLT resin. The Dowex 21K XLT resin could continuously remove over 95% for gold-cyanide complex until 520 bed volumes at the 0.5 mL/min of influent flow rate, however, could not remove lead-cyanide complex at all. The 96% of gold-cyanide complex adsorbed onto Dowex 21K XLT resin could be recovered by mixed solvent with HCl and acetone (7:3 ratio) within 8 bed volumes. Also, the bed volume for gold-cyanide complex using secondly reused Dowex 21K XLT resin was maintained as the 490, therefore, continuous process using Dowex 21K XLT resin can be sufficiently applied to the industrial wastewater containing gold ions.

• Resources Recycling
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• v.15 no.6 s.74
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• pp.41-47
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• 2006

A study for recovering of copper and lead from electronic scraps has been carried out using a combination of bioleaching and solvent extraction. It was found that the citric acid generated by Aspergillus niger could be an imporant leaching agent acting in the solubilization of copper, iron, lead and tin from the electronic scrap. Copper could be selectively extracted by 10% LIX84 from the leaching solution and it recoved 99.9% of metallic copper by electrowinning process. Tin and iron were extracted from the remaining solution by 10% Alamine336 and stripped by NaCl solution. Finally, tin could be recovered as a metallic precipitates from the mixed solution of tin and iron by cementation with iron powder.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.01a
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• pp.205-206
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• 2018

오늘날 인터넷 대중화로 다양한 분야에 걸쳐 누구나 쉽게 정보 공유가 가능한 환경 속에 살고 있다. 최근 모바일 기기들의 확산으로 커피전문점 방문 할 때 정보검색의 영향력이 커짐에 따라 인터넷 후기 등이 작성되어 있는 블로그는 목적지 선택에 많은 영향을 미치고 있다. 본 연구에서는 정보검색을 포함한 기존의 커피전문점의 선택속성의 커피전문점의 만족도와의 관계를 살펴보고자 하였다. 정보검색을 통해 방문한 적이 있는 커피전문점 방문자를 대상으로 176개의 설문지를 회수 하였고, SPSS 18.0를 이용하여 분석하였다. 본 연구에서는 정보검색 일치성을 포함한 커피전문점의 기존의 선택속성들을 독립변수로 두고, 커피전문점의 추천도를 종속변수로 두어 회귀분석을 실시하였다. 분석결과, 정보검색을 통해 커피전문점 방문시 '분위기와 정보검색결과의 일치성', '일반적 선택속성', '커피의 맛', '주차 편리성' 요인이 추천에 유의한 영향을 미치는 것으로 나타났다.

• Resources Recycling
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• v.10 no.6
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• pp.3-8
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• 2001

This study was examed about leaching behavior in order to separate plasticizer selectively before dechlorination from flexible PVC material in alkali solutions at $80~120^{\circ}C$. The dechlorination of that was not almost occurred below $100^{\circ}C$. But the yield of elution of plasticizer was 100% above 5M NaOH. Therefore, by controlling alkali concentration and reaction temperature, it is possible to extract the plasticizer selectively without taking dechlorination.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.47-50
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• 1997

희토류원소의 광 환원 침전 특성이 연구되었다. 환원제로 isopropyl alcohol, 침전제로 (NH$_4$)$_2$SO$_4$가 사용되었다. 그리고 250nm의 파장을 방출하는 수은 램프가 사용되었다. Eu원소만을 함유하는 용액으로부터 Eu+3의 Eu+2로의 광 환원 결과는 97%이상이었으며 과산화수소가 소량 첨가되었을 경우 침전 속도는 증가하였다. 이 결과를 토대로 하여 희토류원소들(Sm,Eu,Gd)을 함유하는 수용액과 유기용액(HDEPH-Dodecan)에 UV광을 조사하였을 시 선택적으로 Eu을 분리해 낼 수 있었다. Eu의 침전 회수율은 두 상의 경우 모두 97%이상이었다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.243-244
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• 2004

금속성 방사성폐기물을 제염하는 설비의 조건으로는 제염계수, 2차 폐기물 발생량, 모재의 회수가능성, 작업자의 안전성(원격조정) 등을 고려하여야 한다. 금속성 방사성폐기물의 오염제거 방법으로 습식제염 방법을 손쉽게 생각할 수 있으나 습식제염은 모재로부터 오염 물질을 선택적으로 제염이 불가능하고 강산 용액을 사용하므로 제염후 발생되는 2차 액체폐기물로 인해 최근 그 적용이 제한되고 있다.(중략)

• Journal of the Korean Chemical Society
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• v.31 no.4
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• pp.308-314
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• 1987

The adsorption behavior of some chelating agents on the Amberlite XAD-7 resin was studied to obtain the optimum conditions for the preparation of chelating agent-XAD-7 resins. The chosen chelating agents are cupferron (CP), diphenylcarbazone (DPC), salicylaldoxime (SAO), thiosalicylic acid (TSA), and dimethylglyoxime (DMG), which have been well known chelating agents to Cu(Ⅱ) and Ni (Ⅱ) ions. Among the chelating agent-XAD-7 resins, SAO-XAD-7 and DMG-XAD-7 resins were evaluated as appropriate impregnated resins by investigating their stabilities in the wide pH range and high abilities to adsorb Cu(Ⅱ) and Ni(Ⅱ) ions. The selective adsorption of Cu(Ⅱ) from Ni(Ⅱ) was possible by changing pH condition by SAO-XAD-7 resin. The adsorption capacities of SAO-XAD-7 and DMG-XAD-7 for Cu(Ⅱ) were $7{\times}10^{-3}mmol$ Cu(Ⅱ) per gram of resin and $2{\times}10^{-3}mmol$ Cu(Ⅱ) per gram of resin, respectively. The quantitative recovery of Cu(Ⅱ) adsorbed by the resin was demonstrated. The adsorption behavior of Cu(Ⅱ) and Ni(Ⅱ) by the single and mixed bed of chelating agent-XAD-7 resin was discussed.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.293-304
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• 2002

Wet purification process for the selective separation of montmorillonite from Gampo 13 and 35 bentonite ores was studied using physical processes such as ultrasonic scrubbing, decantation and centrifugation. Ultrasonic Scrubbing of Gampo 13 and 35 bentonite ores was revealed excellent result at 7 wt.% of slurry density and was almost finished within 30 minutes in the sample of Gampo 13 and 10 minutes in the sample of Gampo 35, respectively After decantation, approximately 52 wt.% from the bentonite of Gampo 13 and 64wt.% from the bentonite of Gampo 35 were recovered as purified products and the CEC was reached up to 119.4 meq/100 g and 124.5 meq/100 g, respectively. Particle separation by centrifugation showed that most of the impurity minerals such as quartz and feldspar were removed within the condition of 1,000 rpm.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.542-548
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• 1989

For the selective separation of proteins, the solubilization and desolubilization of proteins in sodium-di-2-ethylhexyl sulfosuccinate (AOT)-isooctane reverse micellar system were investigated. Protein solubilization increased with increasing the concentration of AOT to 200 mM and then decreased above that concentration. Protein was solubilized into reverse micelles in the pH range below the isoelectric Point of each protein, pH 4-10 for lysozyme and pH 5-6 for trypsin and ${\alpha}-chymotrypsin$, Lysozyme, trypsin and ${\alpha}-chymotrypsin$ were efficiently extracted in the precence of KCl and NaCl while larger molecular weight proteins such as pepsin and BSA had high solubilization with $CaCl_2$. At higher ionic strength all proteins exhibited murk less tendency to solubilize and the increase of ionic strength resulted in the decrease of micelle size. Lysozyme was successfully back transfered at pH 12.2 and 1.0M KCl; trypsin at pH 12.6 and 0.5M KCl; and ${\alpha}-chymotrypsin$ at pH 6.7 and 0.5M KCl. In a test group separation experiments, complete separation of lysozyme from BSA could be obtained.