• Title/Summary/Keyword: thermal property

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Far IR Emission and Thermal Properties of Ceramics Coated Nylon Fabrics (세라믹스 처리된 나일론 직물의 원적외선 방사성능과 보온효과)

  • Yeo, Suk-Yeong;Lee, Dong-Hwa;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.4
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    • pp.515-524
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    • 1998
  • The purpose of this study was to evaluate the thermal properties of ceramics coated nylon fabrics by determining far infra-red emissive properties, heat storage/release and thermal insulation. Far IR emissivity and emissive power were measured for 7~ 140n at 50'C . Three types of ceramics such as cordierite with $\alpha$-alumina, a-alumina with titanium oxide and a-alumina were chosen as specimens. Cordierite with $\alpha$-alumina was chosen to treat on the fabrics due to the good emissive properties on the fabrics. Add-ons and contents of ceramics were analyzed for ceramics and/or polyurethane coated fabrics. For the physical properties, thickness and air permeability were measured. Results showed a difference in the emissive property between ceramics themselves and ceramics coated fabrics. In the ambient temperature, there was no diffenence in emissivity among the different ceramics contents. Thermography showed that when the fabric was heated with the light, surface mean temperatures of fabrics were increased as the contents of ceramics increased, and the heat storage property was confirmed. In case of same thickness and air permeability, the thermal insulation value increased as the contents of ceramics increased because of increasing heat storage and Far IR reflectivity. So there were absorption and heat storage of ceramics for Far IR from human and reflection to human between ceramics coated fabrics and human.

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Heat Treatment Effects on the Thermal Stability and Mechanical Property of Spider Silks from Nephila clavata and Bassaniana decorata (무당거미와 나무껍질게거미줄의 열 안정성 및 기계적 성질에 관한 열처리 효과)

  • Chang, So-Yeon;Lee, Ji-Hye;Lee, Ju-Ha
    • Korean journal of applied entomology
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    • v.48 no.1
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    • pp.109-115
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    • 2009
  • The thermal stability and mechanical properties of Nephila clavata and Bassaniana decorata spider silks were measured and compared with those of aramid and polyester fibers. The thermal stability of the spider silk was lower than those of the commercial aramid and polyester fibers. However, the mechanical properties of the spider silk were far superior to that of the polyester fiber. The effect of the water content of the spider silk on its thermal stability and mechanical property was examined by conducting the silk to heat treatment at $100^{\circ}C$ under vacuum for various times. The results indicated that spider silk subjected to heat treatment for 1.5 hr had excellent thermal stability and mechanical property.

A Study on the Prediction of the Soil Thermal Property Using Predicting the Soil Moisture Contents (수분함량예측기법을 이용한 토양 열특성 예측에 관한 연구)

  • Jeong, S.H.;Kim, D.K.;Choi, S.B.;Bae, J.H.;Ha, T.H.;Lee, H.G.;Cho, S.B.;Kang, J.W.;Kwag, B.M.;Yoon, H.H.
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.576-578
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    • 2000
  • This paper address the prediction method of a soil thermal property depending on soil moisture contents and suggests the guideline to determine the soil thermal resistivity for the calculation of the cuurent carrying capacity of underground power cables in Korea.

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The Oxidation Effect of Semiconductor Carbon Nanotube (반도체 탄소나노튜브의 산화열처리 효과)

  • Kim, Jwa-Yeon;Park, Kyung-Soon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.126-127
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    • 2005
  • Semiconductor carbon nanotube was grown on oxided silicon wafer with Atmosphere Pressure Chemical Vapor Deposition (APCVD) ethmod and investigated the electrical property after thermal oxidation at 300$^{\circ}C$ in air. The electrical property was measured at room temperature in air after thermal oxidation at 300$^{\circ}C$ for various times in air. Semiconductor carbon nanotube was steadily changed to metallic carbon nanotube as increasing of thermal oxidation times at 300$^{\circ}C$ in air.

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New Water-soluble Cutting Fluids Additives Derived from the Thermal Reaction Products of Unsaturated Fatty Acids with Acrylic Acid and Maleic Anhydride

  • Watanabe, Shoji
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.4
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    • pp.372-376
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    • 2003
  • Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

Studies on Thermal Conductivity and Electric Resistance Properties of Microflute Corrugated Paperboard (마이크로플루트 골판지의 열전도도 및 전기저항 특성에 대한 연구)

  • Um, Gi-Jeung;Cho, Yong-Min
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.2 s.120
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    • pp.45-53
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    • 2007
  • When micro flute corrugated paperboards are used for food packaging, they necessarily need to meet the requirements for the distribution, transportation, and storage of food. The requirements could vary ac-cording to the contents in the packaging boxes. Microflute corrugated packaging paperboard for hot foods such as just-made coffee and hamburger requires to have a decent resistance property against high temperature. Along with a recent trend for small-quantity-multi-item upgraded packaging, semiconductor products and consumer-electronic appliances become to be packed using the environmental friendly micro flute corrugated paperboard. In this case, the electric resistance property of the microflute corrugated paperboard becomes important. This study was carried out to investigate on the thermal conductivity and electric resistance properties of micro flute corrugated paperboard.

Effect of Transition Metal on the Thermal Stability and Mechanical Property of Fe-based Amorphous Alloys (Fe기 비정질합금의 열적안정성 및 기계적 성질에 미치는 천이금속의 영향)

  • Gook, Jin Seon;Yoon, Dong Joo
    • Journal of the Korean Society for Heat Treatment
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    • v.14 no.6
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    • pp.345-349
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    • 2001
  • This study has investigated the effect of thermal stability and mechanical property of $Fe_{80-X}P_{10}C_6B_4M_X$(X=2, 4, 6, M=transition metal) amorphous alloys fabricated by the melt-spun process. The glass transition temperature($T_g$), crystallization temperature($T_x$) and hardness increase with decreasing electron concentration (e/a) from about 7.38 to 7.18. The decrease of e/a implies the increase in the attractive bonding state between the M elements and other constituent element. The decrease in a/e leads to the enhancement of the attractive bonding state among the constituent elements which is favorable for the increase in $T_g$, $T_x$ and hardness.

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A Study on the Soil Thermal Property Measurement for the Current Carrying Capacity Evaluation of Underground Transmission Power Cables (지중송전계통의 송전용량평가를 위한 토양열특성 측정에 관한 연구)

  • Kang, J.W.;Choi, S.B.;Jang, T.I.;Yoon, H.H.;Kim, D.K.;Jeong, S.H.;Choi, S.B.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2029-2031
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    • 2000
  • This paper introduces an meanings of the soil thermal properties and an probe method to analyze the soil thermal property. And its method was applied to the soils surrounding the underground transmission power cables at S/S and C/H.

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Evaluation of Microstructure and Mechanical Property of Inconel 600 Degraded under High Temperature (고온 열화된 Inconel 600강의 미세조직 및 기계적 특성 평가)

  • Jung, Kwang-Hu;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.50 no.6
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    • pp.492-497
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    • 2017
  • In this study, we investigated the effect of thermal aging on mechanical characteristics of Inconel 600 nickel-based alloy. The thermal aging was conducted up to 1000 hours at an atmosphere of $650^{\circ}C$. The microstructure of thermally aged specimens was investigated by an optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). In addition, tensile test (strain rate: 2 mm/min) and micro Vickers hardness test were conducted to evaluate mechanical properties with time. As a result of the experiment, Cr-rich carbide continuously precipitated during thermal aging, leading to the change of the mechanical characteristics and fracture mode. With the increase of aging time, tensile strength, yield strength, and hardness gradually decreased. The fracture mode changed from ductile to brittle with the increase of grain boundary carbide.

Measurement of thermal properties by TPS-technique and thermal network analysis (TPS를 통한 열물성치 획득 및 네트워크모델을 이용한 열해석)

  • Yun, Tae-Sup;Kim, Young-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.263-268
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    • 2010
  • Thermal characterization of geomaterials has significant implication on the geothermal energy, disposal of nuclear wastes, geological sequestration of carbon dioxides and recovery of hydrocarbon resources. Heat transfer in multiphase materials is dominated by the thermal conductivity of consisting components, porosity, degree of saturation and overburden pressure, which have been investigated by the empirical correlation at macro-scale. The thermal measurement by Transient Plane Source (TPS) and associated algorithm for interpretation of thermal behavior in geomaterials corroborate the robustness of sensing techniques. The method simultaneously provides thermal conductivity, diffusivity and volumetric heat capacity. The newly introduced thermal network model enables estimating thermal conductivity of geomaterials subjected to the effective stress, which has not been evaluated using previous thermal models. The proposed methods shows the applicability of reliability of TPS technique and thermal network model.

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