• 한국표면공학회지
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• 제48권2호
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• pp.33-37
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• 2015

High efficiency LED device is being concerned due to its high heat loss, and such heat loss will cause a shorter lifespan and lower efficiency. Since there is a demand for the materials that can release heat quickly into the external air, the organic insulating layer was required to be replaced with high thermal conductive materials such as metal or ceramics. Through anodizing the upper layer of Al, the Breakdown Voltage of 3kV was obtained by using an uniform thickness of $60{\mu}M$ aluminum oxide($Al_2O_3$) and was carried out to determine the optimum process conditions when thermal cracking does not occur. Two Ni layers were formed above the layer of $Al_2O_3$ by sputtering deposition and electroplating process, and saccharin was added for the purpose of minimizing the remain stress in electroplating process. The results presented that the 3-layer film including the Ni layer has an adhesive force of 10N and the thermal conductivity for heat dissipation is achieved by 150W/mK level, and leads to improvement about 7 times or above in thermal conductivity, as opposed to the organic insulation layer.

• 한국의류학회지
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• 제17권3호
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• pp.470-474
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• 1993

This study carried out to get some fundamental data for designing lightweight bedding. In This study, the wool blanket, polyester/cotton blended blanket and down quilt were manufactured with a varied materials, structural factors such as yam count, fabric density respectivelyarn. And also, the thermal insulation value of the bedding were measured by warmth retaining tester. In addition, this paper examines the influence of varying materials, structural factors and blanket layers on the thermal insulation effect of the bedding. The main results obtained from this study are as follow : 1. The design of lightweight blankets make an attempting with a varying materials and structural factors such as yam count, fabric densityarn. 2. Almost, the design of lightweight blankets for polyester/cotton blended blanket and down quilt make an attempting without reduction in thermal insulation values. 3. The 6 layers of blanket have less thermal insulation value than the 6 times of blanket for under a layer have. About 27~32% decrease is observed in thermal insulation value of blanket for under 6 layer. 4. The thermal insulation value and areal weight of blankets have a positive relation between the thermal insulation value(Y) and areal weight(X) is based on the following equation. wool blanket : Y = 1.0850X + 0.4188 (r = 0.9992) PIC blended blanket : Y = 0.8845X + 0.3034 (r = 0.9999)

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.585-591
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• 2021

Liquefied hydrogen have advantage which reduces the volume by about 800 times or more compared to hydrogen gas, so it is possible to increase the storage density. However, liquefied hydrogen produced by cryogenic cooling of 20 K or less at normal pressure has a problem of maximizing the insulation effect that blocks heat introduced from the outside. Representative insulation technologies include vacuum insulation and multi-layer insulation materials and in general, heat blocking is attempted by combining insulation technologies. Therefore, in this study, the pressure of the internal vacuum layer was changed to 10^-1, 10^-2, 10^-3 and 10^-4 Torr to confirm the thermal insulation performance of the vacuum jacket valve for transporting liquefied hydrogen. As a result, it was confirmed that the insulation performance improved as the degree of vacuum increased.

• 한국정보통신학회논문지
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• 제13권6호
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• pp.1123-1127
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• 2009

본 연구는 비정질실리콘 박막트랜지스터를 비휘발성 메모리소자로 제작함으로써 스위칭 소자로 사용되는 박막 트랜지스터(TFT)의 응용범위를 확대시키고, 비정질 실리콘 사용에 따라 대면적화에 적합하고 아울러 값싼 기판을 사용할 수 있게 한 비정질 실리콘 비휘발성 메모리소자에 관한 것이다. 이와 같은 본 연구는 유리기판과 그 유리기판위에 증착시켜 패터닝한 게이트, 그 게이트를 덮어씌운 제1 절연층, 그 제1 절연층위에 증착시켜 패터닝한 플로우팅 게이트와 그 플로우팅 게이트를 덮어씌운 제2 절연층, 그 제2 절연층위에 비정질실리콘을 증착시킨 액티브층과 그 액티브층위에 n+ 비정질실리콘을 증착시켜 패터닝한 소오스/드레인층 그리고 소오스/드레인층 위에 증착시킨 소오스/드레인층 전극으로 비정질실리콘 박막트랜지스터 비휘발성 메모리소자를 구성한다.

• 한국농촌건축학회논문집
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• 제23권4호
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• pp.63-71
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• 2021

The purpose of this study was to investigate whether the standard models for rural housing and wooden housing model have performance for hygrothermal and to propose a way of improvement relevant to hygrothermal performance for those models. All of the models to be analyzed were found to have some parts that were absent of stability in terms of performance for hygrothermal. In the process of analyzing the causes and proposing improvement measures, the following conclusions were derived. Fist, The exterior surface of the structure should be composed of a structure with good moisture permeability, and for the interior surface, a variable vapor retarder paper should be applied in consideration of the reverse condensation phenomenon in summer. Second, in terms of performance for hygrothermal, applications of external insulation plaster finish to the exterior wall or of ventilation method using a rafter vent on the roof should be avoided. Third, a rain screen method with a ventilation layer should be applied to the exterior wall, and a method of constructing ventilation layer separated from the insulation layer with a vapor retarder paper should be applied to the roof. Fourth, the application of insulation materials having capillary action, such as wood fiber insulation board or cellulose insulation board, contributes to more stable performance for hygrothermal.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.17-20
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• 2005

This paper reported the temperature history of concrete placed at deck plate slab under cold climate condition by varying with surface insulating type. No curing sheet and simple insulation curing including non-woven fabric, double layer bubble sheet, the combination of double layer bubble sheet and non-woven fabric dropped temperature below zero within 24 hours, which caused frost damage at early age. On the other hand, the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam maintained minimum temperature above $4^{\circ}C\;and\;8^{\circ}C$, respectively. Based on core test results compressive strength of concrete with the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam was higher than those with other curing method due to good insulation effect.

• 한국의류학회지
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• 제19권1호
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• pp.142-148
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• 1995

In this study, FVM (Finite Volume Method) which is one of the 2-dimensional numerical approach has been conducted to anticipate the temperature distribution between skin and clothes by the change of air temperature and fabric characteristics including fabric thickness. Several experimental works have been done to understand the thermal insulation effect (If fabrics on a human body by measuring the averaged temperature in the air layer between skin and clothes or by measuring the thermal resistance of fabrics. However, the formal method is inconvenient to measure the temperature distribution in the air layer to evaluate the insulation rate of the clothes on the skin because the real size of the clearance between skin and the clothes is too small to place the temperature sensor, and in the Tatter method the relationship between human body and the fabrics are ignored. However, the numerical method will be very effective and economical way to evaluate the insulation efficiency of clothes when the computational result is in the reliable range. As the result of this study, the temperature change in the sir layer between skin and clothes was linear to the fabric thickness and this result coincides with many previous experimental results. Moreover, it is possible to predict the optimum fabric thickness for the best thermal insulation in the air layer between skin and clothes.

• 대한기계학회논문집A
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• 제26권4호
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• pp.631-636
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• 2002

It is necessary to improve mechanical and optical properties in the optical disk substrates as the information storage devices with high storage density using blue laser are being developed. Injection compression molding is regarded as the most suitable process to manufacture optical disk substrates for quality recording and read-out. In the present research, the effects of mold temperature and the insulation layer thickness on gapwise birefringence and the land-groove pattern were investigated. It was found that the values of the birefringence distribution were very sensitive to mold temperature history, and the level of birefringence reduced and, furthermore, the quality of replication was improved due to the insulation layer.

• Journal of the Korean Wood Science and Technology
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• 제40권6호
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• pp.431-444
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• 2012

바닥구조의 충격음 차단성능은 바닥의 구성요소에 의해 많은 영향을 받는데, 그중 목조 바닥구조의 경우 중량의 흡읍층과 바닥구조의 강성이 주요한 영향인자로 고려되어 왔다. 본 연구에서는 국내 시공된 목조 건축물에 대해서 현장 실험을 통해 바닥 구성요소가 충격음 차단성능에 미치는 영향에 대해서 살펴보았다. 목조 바닥의 충격음 차단성능은 상대적으로 낮은 저주파수 대역에서의 음압레벨에 의해 전체적인 성능이 좌우되었으며, 흡읍층과 바닥구조의 강성 보강에 의해 저주파수 대역 음압레벨을 감소시켜 충격음 차단성능을 향상시킴을 알 수 있었다. 특히, 바닥난방을 위해 설치되는 시멘트 몰탈층과 같은 충격음 흡수층과 원래 경간의 중간 지점에 보를 설치하여 장선 경간을 줄여줌으로써 목조 바닥의 강성을 증가시킨 경우에 중량 충격음 차단성능이 크게 향상되었다.

• Structural Engineering and Mechanics
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• 제77권5호
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• pp.673-689
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• 2021

This paper addresses the efficiency of thermal insulation layers applied to protect structural elements strengthened by fiber-reinforced polymers (FRP) in the case of fire event. The paper presents numerical modeling and nonlinear analysis of reinforced concrete (RC) columns externally strengthened by FRP and protected by thermal insulation layers when subjected to elevated temperature specified by standard fire tests, in order to predict their residual capacity and fire endurance. The adopted numerical approach uses commercial software includes heat transfer, variation of thermal and mechanical properties of concrete, steel reinforcement, FRP and insulation material with elevated temperature. The numerical results show good agreement with published results of full-scale fire tests. A parametric study was conducted to investigate the influence of several variables on the structural response and residual capacity of insulated FRP-confined columns loaded by service loads when exposed to fire. The residual capacity of FRP-confined RC column was affected by concrete grade and insulation material and was shown to improve substantially by increasing the concrete cover and insulation layer thickness. By increasing the VG insulation layer thickness 15, 32, 44, 57 mm, the loss in column capacity after 5 hours of fire was 30%, 13%, 7% and 5%, respectively. The obtained results demonstrate the validity of the presented approach for estimation of fire endurance and residual strength, as an alternative for fire testing, and for design of fire protection layers for FRP-confined RC columns.