• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.05a
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• pp.76-77
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• 1998

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.183-183
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• 2015

본 연구는 3가 크롬을 주성분으로 하는 크로메이트제의 개발에 관한 것으로, 알루미늄 및 알루미늄 합금에 크로메이트 처리가 용이하며, 높은 내식성을 부여하는 표면처리제의 개발을 목적으로 한다.

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.899-903
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• 2004

A limit switch box is used for a indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a valve actuator. In ship, equipments are required safe and robust because of a rough environment and a specific condition during a voyage. However, the limit switch box is used in an indoor environment generally. Thus, a new limit switch box must be developed which can be used at an outdoor environment. This study designed the limit switch box. The housing of the limit switch box was made by an aluminium die cast method with surface painting after anodizing or chromate coating. In order to evaluate the endurance of the housing, the endurance tests against salt water have been conducted. Experiment results showed that the proposed device provides a reliable performance against salt water.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.295-303
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• 2013

Silane surface treatments have been developed as an alternative for toxic and carcinogenic chromate-based treatments for years. It is consistently observed that ultra-thin films offer excellent corrosion protection as well as paint adhesion to metals. The silane performance is comparable to, or in some cases better than, that of chromate layers. Based on the tetra-ethylorthosilicate(TEOS) and methlyl trieethoxysilane(MTES), inorganic sol was synthesized and formed hybrid networks with $SiO_2$ nano particle and polypropylene glycol(PPG) on Zn alloyed steel surface. According to SST results, addition of 10nm and 50nm $SiO_2$ nanoparticle in synthesized solution improved anti-corrosion property by its shear stress relaxation effect during curing process. Also, SST results were shown that anti-corrosive property was affected by the amounts of organic compounds.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.103.2-103.2
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• 2018

(주)PMPT사는 국내 뿌리산업 분야의 Zn-Ni자동차부품 도금업체로서 남동공단에 위치하고 있다. 하지만 자동차품질 향상에 기본이 되는 도금 기술자료가 부족하여 연구개발에 많은 어려움을 겪고 있다. 또한 미래자동차용 용접부품의 도금 품질향상을 위한 최신 기술정보제공이 필요한 실정이다. 이에 다년간 이론과 경험을 겸비한 도금전문가의 활용이 필요한 실정이다. '아직도 녹슨 자동차를 탈 것인가?' 지난 2003년부터 10년간 '녹슬지 않는 자동차', '녹과의 전쟁'을 목표로 자동차부픔의 품질기술지도가 실시되었다. PMPT사도 이에 동참하여 자체의 경험과 기술로써 용접부 품질을 개선하여 왔다. 하지만 경험에 의존해 왔던 PMPT사 자체의 도금기술로써는 유렵의 BMW사나 Toyota사의 Zn, Zn-Ni 합금도금에 대한 기술변화와 수출경쟁에 대처하기가 어려운 실정이다. 특히 용접부는 자동차 사고의 치명적 결함이다. 이에 도금전문가를 활용하여 해외의 선진도금 기술정보제공과 함께 미래의 자동차부품 품질향상을 위한 기술지원을 실시하였다. 세부적인 기술지원 내용으로서는 Zn, Zn-Ni합금도금제품 용접부품에 6가 Cr을 사용하지 않는 친환경 Chromate Free, Zn-Ni합금도금 용접부 내식성 향상을 위한 Ni의 최적함량과 메커니즘을 지원하였다. 필자가 도금현장에서 근무하면서 터득한 까다롭고 어려워하는 도금기술과 최신의 해외 Chromate Free표면처리 기술을 제공함으로써 수출향상과 품질기술력 향상에 이바지 하고자 하였다.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.433-442
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• 2006

Hexavalent chromium passivation, as very effective anti-corrosion method, can not be used in the field of surface treatment for metal, any more. Throughout the world, this regulations which was applied to automotive industries will be extended to all industries including electronics industries in the near future. Therefore a new anti-corrosion method should be established without delay, and trivalent chromium passivation as an alternatives replace the hexavalent chromium passivation for the time being. This paper gives an overview of the currently available trivalent chromium passivation processes, and then it attempts to give an insight to develop a more effective trivalent chromium conversion coating process for possible substitution of the hexavalent chromium passivation process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.147-148
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• 2011

아연말 코팅은 희생부식에 의한 기재보호의 수단으로서 사용되고 있으며, 현재 볼트의 절반을 차지하고 있는 주요 공정이라 할 수 있다. 본 연구에서는 실제 작업현장에서 사용되는 아연말 코팅액에 3가 chromate액을 배합하는 공정연구등 다양한 공정시스템을 적용하여 생산된 시제품들을 기존 볼트와의 내식성을 상호 비교하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.281-281
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• 2012

We could confirm the results such as excellent anti-corrosion compared to chromate, conductivity, chemical resistance and detergent resistance as the result of analysis of various characteristics of the galvanized steel coated with organic-inorganic developed in this research.

• Journal of Environmental Health Sciences
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• v.23 no.2
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• pp.12-23
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• 1997

The biosynthesis of galactolipid, galactose and the fatty acid composition in E. cdi and B. subtills treated with potassium dichromate(PD, 500 ppm, 500 ppm), potassium chromate(PC, 500 ppm, 500 ppm), cobalt chloride(CC, 100 ppm, 10 ppm) and methylmercuric chloride(MC, 100 ppm, 10 ppm) during the culture were analyzed to compare with the control. The growth rate of cells, the contents of monogalactosyldiglyceride(MGDG), digalactosyldiglyceride(DGDG) and total lipid in the metal compound treatments were lower as compared with the control. And too, the contents of galactose utilized for the biosynthesis of galactolipids in these strains in the various metal compounds treatments were inhibited. The fatty acids used for the MGDG and DGDG formation in E. coli and B. subtills treated with each metal compounds during the culture were showed to the variant compositional change.