• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.19-22
• /
• 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
• /
• 제3권2호
• /
• pp.135-139
• /
• 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
• /
• 제28권4호
• /
• pp.278-284
• /
• 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.

• 센서학회지
• /
• 제6권3호
• /
• pp.237-244
• /
• 1997

A new planar-type microsensor, which had a platinum heater and a sensing layer on the same plane was fabricated on silicon substrate with stress-relieved PSG(phosphosilicate glass)/$Si_{3}N_{4}$(800nm/150nm) diaphragm. The proposed planar-type microsensor could be fabricated by simple silicon process using only 3 masks for photolithography process compared with 5 or 6 masks of the typical micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of the fabricated microheater. Although there are some discrepancy between the simulation result and the result from the fabricated microheater, the thermal simulation by FEM was proved to be an useful method to evaluate the thermal properties of microheater. The sensing characteristics of the fabricated microsensor with the planar-type heater were investigated also.

• 센서학회지
• /
• 제17권3호
• /
• pp.178-182
• /
• 2008

Planar type micro catalytic combustible gas sensor was developed by using nano crystalline $SnO_2$ Pt thin film as micro heater was deposited by thermal evaporation method on the alumina substrate. The thickness of the Pt heater was around 160 nm. The sensor showed high reliability with prominent selectivity against various gases(Co, $C_3H_8,\;CH_4$) at low operating temperature($156^{\circ}C$). The sensor with nano crystalline $SnO_2$ showed higher sensitivity than that without nano crystalline $SnO_2$. This can be explained by more active adsorption and oxidation of hydrogen by nano crystalline $SnO_2$ particles. The present planar-type catalytic combustible hydrogen sensor with nano crystalline $SnO_2$ is a good candidate for detection of hydrogen leaks.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2000년도 추계학술대회 논문집
• /
• pp.84-89
• /
• 2000

Thermal simulation of typical stack-type and newly proposed planar-type micro-gas sensors were studied by FEM method. The thermal analyses for the proposed planar structure including temperatur distribution over the sensing layer and power consumption of the heater were carried using finite element method by computer simulation and well compared with those of typical stack-type micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of a actual device to investigate the acceptability of the computer simulation.

• 한국전기전자재료학회논문지
• /
• 제36권1호
• /
• pp.81-87
• /
• 2023

Heaters using the resistance heating principle are used in various industrial fields that require heat and are also essentially used in bidet among small home appliances. A planar heater and a coil-inserted heater mounted on a conventional commercially used bidet have disadvantages and limitations of complicated manufacturing process and local heating. In this study, silver-palladium (Ag-Pd) powder material was used for a screen-printing process that is more advantageous in achieving simplification than the existing process, and a rod-type heater for bidet was manufactured. The on-off cycle test under actual conditions was conducted to confirm the durability and the capability of the fabricated heater, and the fabricated heater operated more than 2,600 on-off cycles, which means it could be applied for a commercial product. In addition, through the on-off cycles under harsh conditions, the cause of failure was identified after the test that the durability limit temperature of the heater was 850℃. Through Ag-Pd rod heater in this study, it is expected to contribute to the efficient development of electrode materials for heaters and the improvement of the durability of heaters in the future.

• 대한전자공학회논문지SD
• /
• 제41권2호
• /
• pp.33-38
• /
• 2004

측면 연마된 편광 유지 광섬유와 폴리머 평면도파로가 결합된 비대칭 방향성 결합기를 이용하여 가변 광필터를 구현하였다. 소자의 최상부층 위에 형성된 마이크로 스트립 히터에 의하여 유도된 폴리머 평면도파로의 열광학 효과는 결합기의 공진파장을 이동시킨다. 제작된 소자는 720 ㎽의 인가 전력으로 230 ㎚ 이상의 넓은 가변 범위를 보였다.

• 한국태양에너지학회 논문집
• /
• 제35권1호
• /
• pp.69-80
• /
• 2015

A series of numerical analyses was conducted to predict the thermal performance of a solar air heater depending on the hole configuration and geometry in the absorber plate. The planar dimensions of the prototype were 1 m (W) by 1.6 m (H), and the maximum air flow considered was $187m^3/h$. It was considered that protruding holes with a triangular opening in the absorber plate would invoke turbulence in the air flow to enhance the convection heat transfer. Six different hole configurations were investigated and compared with each other, while the hole opening height was considered as a design variable. Three-dimensional transient analyses were performed with a commercial software package on the airflow and heat transfer in the model. The numerical results were analyzed and compared from the view point of the outlet air temperature and its time response to derive the optimal hole pattern and hole opening height.

• 마이크로전자및패키징학회지
• /
• 제24권4호
• /
• pp.39-46
• /
• 2017

본 연구는 평판형 히터용 금속방열판상의 세라믹 절연층 제조, 즉 절연성 금속기판에 관한 것이다. 반도체나 디스플레이의 열처리 공정 등에 사용되는 평판형 히터를 제조함에 있어서, 온도 균일도를 높이기 위해 금속 방열판으로서 열전도율이 높고, 비교적 가벼우며, 가공성 좋은 알루미늄 합금 기판이 선호된다. 이 알루미늄 기판에 발열 회로 패턴을 형성하기 위해서는 금속 기판에 절연층으로서 고온 안정성이 우수한 세라믹 유전체막을 코팅하여야 한다. 금속 기판상에 세라믹 절연층을 형성함에 있어서 가장 빈번히 발생하는 첫 번째 문제는 금속과 세라믹의 이종재료 간의 큰 열팽창계수 차이와 약한 결합력에 의한 층간박리 및 균열발생이다. 두 번째 문제는 절연층의 소재 및 구조적 결함에 따른 절연파괴이다. 본 연구에서는 이러한 문제점 해소를 위해 금속소재 기판과 세라믹 절연층 사이에 완충층을 도입하여 이들 간의 기계적 매칭과 접합력 개선을 도모하였고, 다중코팅 방법을 적용하여 절연막의 품질과 내전압 특성을 개선하고자 하였다.