• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.132-135
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• 1990

This paper presents prediction of insulation lifetime in stress. Essentially, Epoxy resin, when it was subjected to different types of aging condition, produced to varieties of electrical properties and lifetime using spectroscopy and breakdown test. The relationships between the structural and electrical changes of aged epoxy were Investigated.

• KSBB Journal
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• 제17권4호
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• pp.326-332
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• 2002

크로마토그래피 공정 성능 검증의 한 항목인 담체의 수명 검증을 위해 자동화된 미니 크로마토그래피 시스템(MiniValChrom)을 개발하였다. 이 시스템은 크로마토그래피공정의 자동화된 반복수행, 크로마토그래피 각 step의 작동순서 및 공정조건의 자유로운 구성, on-line 실시간 모니터링 및 제어, 여러 담체 수명 검증법의 method file 저장기능 등을 갖추었다. MiniValChrom을 사용하여 BSA와 Cibacron Blue 3G-A를 각각 모델 단백질과 담체로 담체 수명 검증실험을 사례연구로 수행하였다. 담체 수명의 감소는 크로마토그래피 공정을 반복수행하면서 5 cycle 마다 변화하는 HETP값을 측정하여 HETP 값이 1 cm 이상 될 때까지 반복 수행함으로써 담체 수명을 결정할 수 있었다. 본 연구를 통해 개발된 MiniValChrom은 다른 검증 항목이나 multi-product 생산공장 내 크로마토그래피 공정 검증에도 유용하게 쓰일 수 있을 것으로 기대된다.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.339-341
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• 2008

Catalytic trimerization of isobutene to produce triisobutenes has been performed over cation-exchange resin and zeolite catalysts. Resin catalysts have the advantage of long lifetime and high trimers selectivity even though the regeneration of an aged catalyst is not satisfactory. On the contrary, zeolite catalysts can be regenerated facilely by simple calcination in air even though the lifetime is short and trimers selectivity is low probably due to small pore size and strong acidity, respectively. It is, therefore highly desirable to develop an inorganic acid catalyst with macro- or meso-pores to show catalytic performances similar or superior to those of macroporous resin catalysts.

• 박물관보존과학
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• 제10권
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• pp.75-88
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• 2009

금속유물 강화제로 널리 사용 중인 아크릴계 수지 Paraloid^TM B-72(EMA copolymer)의 수명예측을 위한 연구이다. 수명인자로서는 온도를 고려하였으며, 수명예측을 위한 test parameter로써 색도를 선택하였다. 그 결과, 같은 농도의 도막에서 온도에 대한 노화가 주요 요인이라는 것을 알았다. 즉 환경온도 24℃에서 24시간일 때 수명은 12.0년, 20℃에서 24시간일 때 수명은 17.1년, 16℃에서 24시간일 때 수명은 24.5년으로 예측되었다. 이 실험을 평가는 Arrhenius 관계식을 이용하여 예측하였다.

• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.758-763
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• 2000

Dielectric strength of insulators made of epoxy composites rapidly decreases due to ageing to interfaces between the matric resin and filler particles. The adhesion variation of interfaces caused by moisture absorption also alters electrical properties that are the basic characteristics of insulators, particularly, in outdoor use. In this paper, electrical properties of epox/SiO$_2$composites were investigated at boiling absorption condition to observe the influences of moisture. In order to analyze the basic physical properties of samples, scanning electron microscopy and DC, AC and impulse voltage dielectric strength were measured. Also, the breakdown time of samples was measured under AC 6[kV] applied voltage, and the variation of lifetime was verified by using Weibull distribution function.

• 한국정밀공학회지
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• 제17권6호
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• pp.96-102
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• 2000

The finishing process for dies and molds is an important process because it has influence on final quality of products. And it is difficult to automatize finishing process so that the process has depended on expert's skill until now. However, recently a study on development of die automatic finishing machine has been progressed, and actually this machine is applied to fabrication of die. But the research about tooling system is not enough and finishing tool must have high machining efficiency and adaptability of curved surface. So, this study investigated the application of conductive elastic tool which is composed of metal-resin bonded pellet and elastic backing material. The metal-resin bonded pellet is used to finish the surface by conventional mechanical grinding or electro-chemial grinding method. And elastic backing material is used to follow the curved surface. So conductive elastic tool has long lifetime, uniform removal rate and adaptability of curved surface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.444-447
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• 2003

All objects with some temperature above absolute zero radiate in the infrared. The intensity of the infrared radiated from a object defends on the condition and temperature on the surface of the one. The present, these techniques are frequently adopted into diagnosis for electricity equipments. Simply, however, the applied techniques are passive thermal testing for the detection of loosened terminals and overcurrent. In this paper, a infrared thermal imager was applied to high voltage windings of cast resin transformers, and the accumulated value of the result temperatures was used for evaluating remained lifetime of them. At each aging level, dielectric loss tangent test was carried out. The results offered capabilities for deciding the condition of the transformers suffering difficulties to diagnose.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.485-487
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• 2000

Dielectric strength of insulators made of epoxy composites rapidly decreases due to ageing to interfaces between the matrix resin and filler particles. The adhesion variation of interfaces caused by moisture absorption also alters electrical properties that are the basic characteristics of insulators, particularly, in out door use. In this paper, electrical properties of epoxy/$SiO_2$ composites were investigated at boiling absorption condition to observe that influence of moisture. The breakdown time of samples were measured under AC 6[kV] applied voltage, and the variation of lifetime was varified by using Weibull distribution function.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.207-211
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• 2007

The durable lifetime of RC structures is shortened by various reasons, which are the generation of cracks in construction and service term, the exterior deterioration according to climatic condition, the surface damage due to chloride attack and the corrosion of reinforced bars. The durability of concrete structures is nevertheless able to be increased by the method and the material of reinforcement and repair. The epoxy resin is widely used for reinforment and repair of concrete because of the superiority in mechanical property, adhesive property, abrasion resistance, impact resistance and chemical resistance. The epoxy cement mortar with hardening agent has a lot of disadvantages that are troublesome mixing work, weakened weatherability and high cost for hardening agent. In this study, the mix proportion of mortar is presented just only with epoxy resin and some admixtures, and the test result of mortar without hardening agent shows the higher strength than the mortar with hardening agent. In the mix proportion, the weight of epoxy resin must be less than 15% of the unit weight of cement, and 10% of unit weight of cement is adequate for the weight of admixtures.

• Journal of Advanced Marine Engineering and Technology
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• 제33권3호
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• pp.387-394
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• 2009

It has been observed that coated steel structures are rapidly deteriorated than designed lifetime due to acid rain caused by air pollution etc.. Therefore improvement of corrosion resistance of anti-corrosive paint is very important in terms of safety and economic point of view. In this study corrosion resistance for five kinds of anti-corrosive paints including acryl, fluorine and epoxy resin series were investigated with electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements etc.. There were somewhat good relationships between values measured by electrochemical methods such as corrosion current density obtained by cathodic and anodic polarization curves, value of impedance estimated with AC impedance, and polarization resistance on the cyclic voltammogram, for example, corrosion current density was decreased with increasing of values of impedance and polarization resistance on the cyclic voltammogram. However their relationships between corrosion current density and corrosion potential were not well coincided each other. Consequently it is considered that although a corrosion potential of F101 of fuoric resin series shifted to negative direction than other anti-corrosive paints, its corrosion resistance, indicating on the cathodic and anodic polarization curves, AC impedance curves and cyclic voltammogram, was the most superior to other paints, whereas A100 containing arcylic resin showed a relatively poor corrosion resistance compared to other paints.