• Design & Manufacturing
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• 제15권1호
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• pp.32-40
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• 2021

Mold design for in-mold coating was carried out to achieve simultaneous injection molding and two-color coating for car gas cap cover. The developed mold includes one core and three cavities which are composed of a substrate cavity and two coating cavities. To provide a sealing edge for complete seal during the second coating, the first coated material was used at the boundary between the first coating and the second one, and injection molded substrate was used at the parting line. The materials used were PC/ABS for substrate and 2-component Polyurea for coating. Through experiments, it was found that the suggested sealing edges were effective for complete seal during the second coating. In cavity pressure traces, there were three peaks caused by mold closing, coating-material injection and cleaning-piston advancement inside the mixing head. The cavity pressure increased with decreasing coating thickness.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.125-126
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• 2022

As environmental problems around the world become serious, Korea has also raised the greenhouse gas reduction in the building sector to 32.8% compared to 2018, and efforts to reduce carbon in buildings are expanding. Recently, research is being actively conducted to reduce carbon in the long term by expanding the scope of greenhouse gas indirect emissions (Scope3), and even within the domestic Green Standard for Energy and Environmental Design(G-SEED) by quantitatively evaluating the environmental impact of buildings during the entire life cycle. However, it is difficult to accurately evaluate the carbon emission of the transportation process by assuming the material transport distance in the evaluation of the Life Cycle Assessment(LCA). Therefore, in this study, the main building materials of the building were selected through case evaluation and the carbon emission of the material transport process was derived based on the actual transport distance, and this was compared and analyzed with the theoretical LCA results.

• 청정기술
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• 제18권3호
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• pp.301-306
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• 2012

급성장하고 있는 태블릿 PC와 스마트 폰과 같은 모바일 기기들은 제품 표면 보호를 위해 강한 소재인 터치스크린패널을 장착하고 있다. 따라서, 화학강화유리의 수요는 증가하게 되었고, 수요가 증가함에 따라 화학강화유리의 폐기량도 증가하게 되었다. 이 연구의 목적은 물질전과정평가(material life cycle assessment, MLCA) 기법을 사용하여 터치스크린패널에 사용되는 화학강화유리의 환경영향평가를 하는 것이다. MLCA의 소프트웨어로는 그란타의 씨이에스(CES), 시마프로(SimaPro), 가비(Gabi)를 사용하였다. 씨이에스 소프트웨어(CES software)를 통하여 2.7, 5.7, 10.3 inch 두께의 화학강화유리의 환경영향평가를 2가지 경우(폐기, 재사용)를 고려하여 수행하였다. 그 결과, 2.7, 5.7, 10.3 inch 화학강화유리를 재사용할 경우에 사용되는 에너지 값과 $CO_2$값은 폐기할 경우에 비해 약 51.4%, 46.6% 감소하는 것을 확인하였다. 시마프로 소프트웨어(SimaPro software)를 통해서는 11가지 영향범주를 평가하였는데, 11가지 영향범주 중에서 화석연료(fossil fuels), 무기물(inorganics)과 기후변화(climate change)가 주된 환경부하의 원인으로 나타났다. 그리고 가비(Gabi) 소프트웨어를 통해서 환경영향의 주된원인이 안티몬(antimony), 불화수소(hydrogen fluoride)라는 것을 알 수 있었다.

• 항공우주기술
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• 제5권2호
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• pp.143-148
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• 2006

본 문서는 KSLV-I의 해상운송과정에서 겪게 될 진동하중조건의 기초자료 획득을 위해 수행된 해상운송 측정결과를 요약정리 한다. KSLV-I은 부산에서 전남 고흥 외나로도의 우주센터로 해상을 통해 운송될 예정이다. 해상운송시의 진동하중은 발사체나 이송치구를 설계할때 반드시 고려되어야 하는 설계인자 중 하나로서, 실제 해상운송시의 하중을 측정하여 그 크기를 확인해야 할 필요가 있다. 본 문서에서는 KSLV-I을 수송할 선박과 동일한 규모인 바지선(예인선으로 견인)을 대상으로 운항중에 3축가속도와 3축각속도 신호를 측정하여 해상운송하중을 획득한 결과를 보여준다. 그 결과 기존의 미군사규격이나 Zenit-3SL(Sea Launch)의 하중조건보다 양호함을 확인할 수 있었다.

• 한국전기전자재료학회논문지
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• 제28권11호
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• pp.694-697
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• 2015

We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various RF powers for the improvement of physical properties in carbon fiber (CF). All sputtered carbon films exhibited amorphous structure, regardless of RF powers, resulting in uniform and smooth surfaces. The hardness and elastic modulus are increased with the increase of RF power, and the adhesion and friction properties of carbon films were improved with the increase of RF power. In the results, The increase of RF power in the sputtering method improved tribological properties of the carbon films, and these attributes can be expected to improve the physical properties of the carbon fiber reinforcement plastics.

• 융복합기술연구소 논문집
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• 제6권2호
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• pp.25-28
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• 2016

Recently, due to the climate change by global warming, the amount of snow has increased. The situations were demanded to use many snow removal materials. The snow removal materials that used in Korea were solid chloride deicing material. That is calcium chloride($CaCl_2$) and sodium chloride(NaCl). Solid chloride baesd snow removal materials have various property, for example good freezing point depression, deliquescence and economical solvents. However, there are problems such as water pollution, high corrosiveness and ecocide. For such reason, development of eco-friendly deicer was required obligatorily. This study investigated development situation of eco-friendly deicer materials.

• 한국안전학회지
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• 제31권4호
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• pp.22-26
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• 2016

"Always-on" small ventilators are likely to experience thermal decomposition of insulating material due to thermal, electrical, mechanical and environmental influences, and lose insulating properties by the process of oxidation and physiochemical reaction. This increases the risk of electrical fire because of layer short, short circuit, overload and Plastics are usually used to make ventilator and ventilator enclosures since they make less noise and are cheaper. Although more preferred than iron, plastic, a combustible material, has a higher risk of fire. In this study, several experiments were carried out to find out how RCD(Residual Current Protective Device) and Thermal fuses, which are electric motor protection devices, work and what needs to be done to reduce the risk of fire.

• Tribology and Lubricants
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• 제10권3호
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• pp.39-46
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• 1994

In order to investigate the effect of the ceramic reinforcements on the wear properties of aluminum bronze composites, Cu-8wt%Al aluminum bronze alloys reinforced with the Saffil alumina short fiber were produced by the powder metallurgical method and tested by a pin-ondisc wear testing machine. The wear surfaces of the pin specimens and discs, wear debris, and the cross sections of the wear specimens were observed by SEM. The wear mechanism according to various wear conditions and the change of microstructure in the composites were also discussed. In the results, the reinforcement of the composites with alumina short fiber was very effective at the higher applied load over 10N. The material transportation to the counter disc was observed in the alloy specimens without reinforcements. However, the composites reinforced with ceramic particles and fibers showed the resistance against the material transportation.

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.813-820
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• 2015

We have studied commercialization and process optimization of protective film on transparent conductive coated substrate, nano silver on flexible PET (poly ethylene terephthalate), by means of roll-to-roll micro-gravure coater. Nanosilver on flexible PET substrate is potential materials to replace ITO (indium tin oxide). Protective film is most important to maintain unique silver pattern on top of transparent PET. PSA pressure sensitive adhesives) was developed solely for nano silver on PET and protective film was successfully laminated. We have optimized all process conditions such as coating thickness, line speed and aging time & temperature via experimental design. Transparent conductive film and its protective film developed in this research are commercially available at this moment.

• 융복합기술연구소 논문집
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• 제6권1호
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• pp.1-5
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• 2016

Additive manufacturing is converting a digitally designed object into a tangible three dimensional solid using an additive process where materials are applied in successive layers with no or very limited material waste. It can be distinguished form traditional manufacturing which begins with a fixed amount of raw material and removes excess to arrive at the final product. Generally there are five stages to the additive manufacturing supply chain, namely materials, systems, software, application design and production. In this paper, recent market trends and technology about additive manufacturing based on supply chain are analyzed and reviewed.