• 한국표면공학회지
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• 제47권5호
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• pp.244-251
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• 2014

In recent years, self-healing coatings have been the subject of increasing interest. The ability of such coatings to self-repair local damage caused by external factors is a major factor contributing to their attractiveness. Metals are extensively used in modern society in a range of applications from infrastructure to aircraft to consumer products. The protection of metals, primarily from corrosion has been an active area of materials science for many years. The aim of this review is the demonstration for recent progress achieved in the development of carrier-based self-healing coatings for the protection of metals. This review mainly covers the reports published after 2010. Two main types of carriers for corrosion inhibitors or healing agents-polymer capsules and porous composite inorganic nanoparticles-are described.

• 농약과학회지
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• 제2권3호
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• pp.36-44
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• 1998

각기 다른 종류의 입상담체(extruded pellets, sands, zeolites)를 이용하여 보조제의 종류와 조성을 달리하고 주성분을 피복 또는 흡착시켜 제제한 제제품과 조립흡착식으로 제조된 butachlor + chlometholefen(3.5 + 7.0%, 부로트 입제) 혼합입제의 부유성, 수중확산 또는 붕괴성, 수중용출도 및 생물효과를 비교하여 우수한 물성 및 효과를 갖는 용출제어형 입제 제조법을 개발하고자 하였다. 물성이 다른 원제를 이용하여 입제를 제조하기 위해서 여러 제조방식을 이용하는데 원제 2개 이상 혼합된 입제를 제조하기 위해서 고상인 원제와 증량제 및 보조제를 첨가시켜 조립한 뒤 여기에 액상 원제를 흡착시켜 제조한 입제는 우수한 부유성과 수중붕괴성, 안정된 수중용출도를 나타내었으며, 생물효과도 안정적으로 발휘시킬 수 있었다. 기립입자를 담체로 이용하여 피복 또는 흡착시킨 기립피복식 입제들은 부유성, 수중붕괴성 및 생물효과면에서 기존 입제와 대등하거나 우수하였지만 불안정한 수중용출 경향을 나타내었다. 그러나 모래피복형의 경우 기립피복식이나 지오라이트피복식과 달리 액상의 binder가 비교적 안정적으로 주성분들의 수중용출에 도움을 주었고 분상의 dispersing agent보다 액상이 부유성, 수중붕괴성 및 생물효과 면에서 기존과 비슷했거나 좋았던 결과로 볼 때 적절한 binder와 액상의 dispersing agent를 선택하여 제조한다면 기존 조립흡착식 입제와 대등하거나 우수한 물성 및 생물효과를 발현하는 입제를 개발할 수 있는 제조방식인 것으로 판단되었다.

• 약학회지
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• 제38권6호
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• pp.637-645
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• 1994

The effect of various drugs on the stability of the liposomal membrane of phosphatidylcholine and cholesterol was studied, employing the fluorescence self-quenching method. Calcein was entrapped into the phospholipid small unilamellar vesicles and the leakage of the fluorescence probe was monitored on adding the drug to the system. The results of the experiments showed that phenothiazine derivatives, some potent local anesthetics and surface active agents were very effective in inducing the leakage of calcein from the liposome. The leakage-inducing activity of these drug substances has been ascribed to their surface activity and the perturbation of the liposomal membrane by these substances. On the other hand drug substance with low surface activity or without amphiphilic moieties did not show any effect or only small effect on the leakage of calcein from the liposomes. The effect of lipid concentration on the stability of the liposomes was also investigated to show that the higher concentrations of lipid more drug was required to induce the leakage. The effect of surface charges of vesicles was also studied, and the results showed that the charge on the liposomes enhanced the stability of the liposomes against the leakage-inducing activity of these drug substances.

• 열처리공학회지
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• 제15권5호
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• pp.213-218
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• 2002

In order to develop the economic and environmental water-soluble black coloring agent, some adequate chemical mixtures were mixed and this solution was applied to coat quenched and tempered 51B20 steel bolt. Some basic properties of the solution and characteristics of the coated film in addition to the corrosion resistance were investigated. The developed 100 kg of water-soluble black coloring agent solution was a chemical mixture consisted of 10 kg of aqueous coloring agent, 40 kg of surface active agent, 0.3 kg of anti-foam agent and $50{\ell}$ of water. The coated film of the bolt was composed of hard layer of about $2{\mu}m$ and the disbondable soft layer of about $4{\mu}m$ above the hard layer. Many surface active agents peaks and a few hydrophilic peaks were observed in the coated film. Surface roughness value of the coated bolt was lower than that of the non-coated bolt. Corrosion resistance of the coated bolt considerably improved and also relatively showed a good polarization resistance at test condition of $40^{\circ}C$ colorizing temperature and 5% the solution concentration in 3% NaCl anodic polarization test. Initial appearance time of the surface rust was greatly retarded owing to the coated film in salt spray test.

• 공업화학
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• 제10권2호
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• pp.263-267
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• 1999

사용이 끝난 폐촉매의 NO 제거 활성은 새 촉매의 약 27%로 크게 저하되어 있었다. 폐촉매의 비표면적은 새로운 촉매의 약 63%로서 활성소실의 주 원인은 소결에 의한 표면적 감소, 촉매표면의 활성물질의 농도저하, 중금속에 의한 활성점의 피독 등으로 판단된다. 폐촉매의 재생은 주로 피독 물질의 제거에 중점을 두었는데, $80^{\circ}C$ 물을 이용하여 30분에서 2시간 처리하여 재생한 촉매가 가장 좋은 효과를 보였으며 이는 중금속 K와 Na가 제거된 때문으로 판단된다. 새로운 촉매를 기준으로 하였을 때 폐촉매의 표면적당 재생된 활성은 약 79%이었으나 질량당 재생된 활성은 약 49%이었다.

• 대한화학회지
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• 제44권4호
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• pp.337-342
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• 2000

현재 한전의 화력발전소에서 사용되는 실리콘 오일계 소포제의 품질관리를위해 각종 실험을 실시한 결과 제조업체별로 다른 계면활성제 (예를 들면 유화제와증점제)를 사용하고 있어 가가의 소포제는 특징적인 물성을 나타냄을 확인할 수 있었다. 보다 간편하면서도 정확한 소포제의 품질관리를 위해 고안된본 실험은 소포제에 사용된 계면활성제의 종류나 양에 관계없이 소포제에 함유된 실리콘 오일의 정확한 함량을 측정하고자 시도하였다. 우선 매우 간단한 실험 기구로 행할수 있은 중량법이나 원심분리법을 사용하여 실리콘 오일의 함량을 구한 다음, FT-IR에 의한 분광법을 사용하여 비교${\cdot}$확인하였다. 원심분리법은 바탕실험과 실제 소포제에 대해 적용한 결과, 소포제 내의 실리콘 오일의 전량 회수되지 않으므로 오일 함량의 분석에는 좋은 방법이 될 수 없음을 확인하였다. 한편 일부 회사에서 제조된 소포제의 경우 이들 방법 사리에 상당한 차이를 나타내었다. 비교실험 결과, FT-IR에 의한 분광법이 적은 시료의 양으로 짧은 시간내에 손쉽게 분석이 가능하고 좋은 재현상을 나타내므로, 언급한 전처리 방법과 함께 사용할 경우 첨가된 계면활성제의 종류와 양에 관계없이 좋은 결과를 얻을 수 있다고 판단된다.

• Journal of Dairy Science and Biotechnology
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• 제16권2호
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• pp.98-105
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides(CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 1부
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• pp.182-186
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• 2012

human tyrosinase (hTyr) catalyzes first and the rate limiting step in the synthesis of polymerized pigment, melanin which determines skin, hair and eye colors. Mutation of hTyr often brings about decrease of melanin production and further albinism. Meanwhile, a number of cosmetic companies providing skincare products for woman in Asia-Pacific region have tried to develop inhibitors to bright skin color for several decades. In this study, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from bacillus megaterium as a template to serve structural information of hTyr. According to our model and sequence analysis of type 3 copper protein family proteins, two copper atoms of active site located deep inside are coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Cavity which accommodates substrates was like funnel shape of which entrance was wide and expose to solvent. In addition, protein-substrate and protein-inhibitor complex were modeled with the guide of van der waals surface generated by in house software. Our model suggested that only phenol group or its analogs can fill the binding site near nuclear copper center because inside of binding site has narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogensis agents.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과학회 1998년도 제46회 춘계 유가공 심포지움 - 우유 및 유제품의 기능성
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• pp.22-29
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides (CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These results suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.158-161
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• 2003

중수로형 원전의 감속재 상층기체에 포함되어 원전 주변 대기로 방출되는 방사성이산화탄소$(^14CO_2)$를 효과적으로 흡착하여 분리, 고정할 수 있는 고효율 흡착제를 개발하기 위해, 활성탄 및 활성탄섬유에 금속수산화물(LiOH)을 담지한 몇 가지의 흡착제를 대상으로 XRD, BET, SEM/EDX 분석을 수행하였으며, 이산화탄소 흡착 성능을 시험하였다. 성능 시험 결과, 활성탄과 LiOH를 물리적으로 혼합한 시료가 함침법으로 LiOH를 활성탄에 담지한 시료에 비해 흡착 성능이 우수함을 알 수 있었으며, 활성탄의 표면을 개질한 결과 1N 질산으로 처리하였을 때에도 흡착성능이 향상됨을 확인하였다.