• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.19-22
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• 2003

The purpose of this study is to analyze the curing effect of planar surface heater for concreting in cold weather. Some experiments were conducted to evaluate the temperature history of concrete structures cured with heating sheets. Results are as follows ; (1) The temperature of concrete showed continuously rising trend with the heating by planar surface heater under the cold environmental condition of 3~-12$^{\circ}C$. And after about 24 hours the maximum temperature of concrete was reached at 25~3$0^{\circ}C$. (2) The temperature of slab concrete heated by planar surface heater of 130W/$m^2$ was at least $25^{\circ}C$ higher than that of an exterior air, and the curing performance was much more effective than heating by hot wind machine. (3) Through the curing by planar surface heater for 48 hours, the concrete maturity of about 1.5 times to heating by hot wind machine was acquired.

• 한국건축시공학회지
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• 제3권2호
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• pp.135-139
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• 2003

The purpose of this study is to analyze the curing effect of planar surface heater for concreting in cold weather. Some experiments were conducted to evaluate the temperature history of concrete cured with heating sheets in the laboratory conditions. As the results, It was showed that the 130W/$m^2$-heater could raise the inner temperature more than $20^{\circ}C$ under the environmental condition of -5~$-20^{\circ}C$. And the temperature of concrete cured by the 200W/$m^2$-heater was 5~$10^{\circ}C$ higher than that of concrete cured by 130W/$m^2$-heater. Finally, through the curing by the planar surface heater during the first 1.5~2 days, it is possible to secure the sufficient maturity of concrete.

• 청정기술
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• 제28권4호
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• pp.278-284
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• 2022

본 연구는 1차원의 Carbon nanotube (CNT)와 2차원의 MXene을 최적의 비율로 배합한 우수한 전기전도성과 발열특성을 가진 저차원 복합소재 기반 면상발열체를 제안한다. CNT와 MXene을 친환경 소재인 Waterborne polyurethane (WPU)과 배합하되, MXene과 CNT의 중량비율을 3:1, 1:1, 1:3, 1:7, 1:14로 다르게 적용하고 WPU는 동일한 비율로 적용하였다. 그 결과, CNT 비율이 높을수록 면저항이 낮아지고 발열온도가 높아지는 것을 확인하였다. MXene과 CNT를 1:7, 1:14로 배합하는 경우 CNT-WPU 면상발열체보다 더 낮은 면저항과 높은 발열온도를 보여주었다. 이는 1차원 CNT와 2차원 MXene의 최적 배합으로 고밀도 네트워크가 형성되어 평평한 표면이 형성되기 때문이다. 위 우수한 전기적 특성을 가진 저차원 복합소재는 플렉서블 소자에 유용하게 활용될 것으로 기대된다.

• 한국산업융합학회 논문집
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• 제27권3호
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• pp.685-692
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• 2024

Currently used heating elements are metal and non-metal heating elements, including various types of heaters, and resistance line heating elements have a problem of decreasing thermal efficiency over time, so to solve this problem, a planar heating element using high-purity carbon materials and oxidation-resistant inorganic compounds was applied. Through the manufacture of planar heating elements using CNT, ruthenium composite materials, and ruthenium oxide, physicochemical performance and capacity were increased, and instantaneous responsiveness was increased. Through thick film technology applicable to various base bodies, fine patterns were formed by the screening method in consideration of the fact that the performance of the heat source depends on the viscosity and pattern shape. The heating element was manufactured by thick film printing technology by mixing ruthenium oxide, CNT, Ag, etc. The characteristics of each paste were analyzed through viscosity measurement, and STS 430 was used as a base. Surface temperature and efficiency were measured by testing heaters manufactured for small wind tunnels and real-vehicle experiments. The surface temperature decreased as the air volume increased, and the optimal system boundary was found to be about 200 mm. Among the currently used heating elements, this paper manufactured a planar heating element using thick film technology to find out the relationship between air volume and temperature, and to study the surface temperature.

• 한국정보통신학회논문지
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• 제8권7호
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• pp.1436-1441
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• 2004

산화물 반도체의 비정상적 전류-전압 특성을 조사하였고, 그 전류-전압 특성을 산화물 반도체 가스센서에 적용하여 히터없이 감지막의 자기발열 메커니즘에 의해 환원성 가스를 검지하는 새로운 방법을 제시하였다. 평면 구조의 후막 가스센서는 WO3가 도핑된 SnO2 산화물 반도체를 이용하여 스크린 프린팅 방법으로 제조하였다. 감지막에 공급된 전압은 감지막의 발열을 초래하고 이 센서에 가스가 노출될 경우, 가스 감지막 표면의 재 반응에 의하여 전류는 급격히 변화하고 이로써 가스를 검지 할 수 있게 되었다. 이 가스 검지 구조의 가장 특이하고 매력적인 면은 검지를 위해 모든 산화물 반도체 가스센서가 가지고 있어야 하는 히터가 필요 없다는 것이다. 이 새로운 감지 방법을 C2H5OH 가스검지에 적용시켜 보았다.