• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.4
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• pp.347-355
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• 2014

Thermal problems that are directly related to the lifetime of an electronic device are becoming increasingly important owing to the miniaturization of electronic devices. To solve thermal problems, it is essential to study thermal stability through thermal diffusion and insulation. A honeycomb sandwich plate has anisotropic thermal conductivity. To analyze the thermal deformation and temperature distribution of a system that employs a honeycomb sandwich plate, the thermal and elastic properties need to be determined. In this study, the thermal and elastic properties of a honeycomb sandwich plate, such as thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and shear modulus, are predicted. The properties of a honeycomb sandwich plate vary according to the hexagon size, thickness, and material properties.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2279-2282
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• 2010

In this work, the electrical and thermal properties of polyimide/multi-walled carbon nanotube (MWNT) nanocomposites were investigated. The polyimide/MWNT nanocomposites contained from 0 to 2.0 wt % of MWNT. The electrical properties of the polyimide films were characterized by a specific resistance measurement. The thermal properties were evaluated using thermogravimetric analysis (TGA) and a differential scanning calorimeter (DSC). It was found that the thermal properties of the polyimide nanocomposites increased with increasing MWNT content and specific resistance as well. This result indicated that the crosslinking of polyimide/MWNT nanocomposites was enhanced by good distribution of the MWNT in the polyimide resins, resulting in the increase of the electrical and thermal properties of the nanocomposites.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.246-248
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• 1994

The Electrical properties of thin $SiO_2$ film by rapid thermal processing have been investigated and this film has been compared with thermal $SiO_2$ film by furnace. The RTO(rapid thermal oxide) film annealed in Ar ambient represent more superior properties than thermal $SiO_2$ film by furnace at breakdown field and leakage current. The RTO(rapid thermal oxide) film annealed in $NH_3$ ambient represent more inferior properties than thermal $SiO_2$ film by furnace at electrical properties, but the capacitance was improved 15-25% than the conventional oxide film.

• Journal of Biosystems Engineering
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• v.4 no.2
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• pp.53-63
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• 1979

The knowlege of thermal properties of rough rice has become of greate importance to the analysis of heat and mass transfer phenomenon in rice drying and storage process. Some information is available on the thermal properties of rough rice in foreign countries but is not available for these properties in Korea. A fundamental study was made to determine the thermal conductivity and thermal diffusivity of rough rice with line source method and to select current and resistance suitable for these properties from investigating the effect of current and resistance of heating wire on the temperature rise. The result of this study may be summarized as follows ; 1. Even through the power per unit length of heating wires is about the same, the tendency of temperature rise showed a little difference among them , and the suitable range of it for thermal properties was found to be 3.56-5.37w/m. 2. the most desirable resistance and current of heating wire was 18.40 ohm/m, 0.44 amperes among three kinds of heating wires and currents, respectively. because it took 13 minutes or so for the heating wire to reach equilibrium temperature. 3. The thermal conductivity of rough rice was 0.120-0.130 w/m$ ^\circ C$. and thermal diffusivity of it was $5.8210 $\times10^{-8} -9.7529 $\times10^{-8} m^2 /s.$ 4.The thermal conductivity showed a little difference in variation with resistance of heating wire but the variation of current of heating wire at the same resistance did not affect the thermal conductivity , and the thermal diffusivity was not affected by the variation of resistance and current.

• Transactions of Materials Processing
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• v.18 no.5
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• pp.401-409
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• 2009

The change of the thermal properties of exothermic and insulating materials with the mixing condition of raw materials which is the most important factor for exothermic & insulating materials was investigated by using the evaluation system of the thermal properties of exothermic and insulating materials. In this study, the effect of the thermal properties of the exothermic & insulating materials such as exothermic properties, endothermic properties, insulating properties, maximum temperature of molten metal, ignition time of exothermic & insulating materials and temperature recovery time on the mixing ratio of reductant and oxidant, types of reductant, and particle sizes of reductants was examined. It could be expected to design the mixing condition of raw materials for various exothermic and insulating materials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.118-126
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• 2009

The change of the thermal properties of exothermic & insulating materials with mixing condition of raw materials which is the most important factor for exothermic & insulating materials was investigated by using the evaluation system of the thermal properties of exothermic & insulating materials. In this study, the effect of the thermal properties of the exothermic & insulating materials such as exothermic properties, endothermic properties, insulating properties, maximum temperature of molten metal, ignition time of exothermic & insulating materials and temperature recovery time on the mixing ratio of reductant and oxidant, types of reductant, and particle sizes of reductants was examined. It could be expected to design the mixing condition of raw materials for various exothermic & insulating materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.14-14
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• 2011

Graphene is known to possess excellent thermal properties, including high thermal conductivity, that make it a prime candidate material for heat management in ultra large scale integrated circuits. For device applications, the key parameters are the thermal expansion coefficient and the thermal conductivity. There has been no reliable experimental determination on the thermal expansion coefficient of graphene whereas the estimates of the thermal conductivity vary widely. In this work, we estimate the thermal expansion coefficient of graphene on silicon dioxide by measuring the temperature dependence of the Raman spectrum. The shift of the Raman peaks due to heating or cooling results from both the intrinsic temperature dependence of the Raman spectrum of graphene and the strain on the graphene film due to the thermal expansion mismatch with silicon dioxide. By carefully comparing the experimental data against theoretical calculations, it is possible to determine the thermal expansion coefficient. The thermal conductivity is measured by estimating the thermal profile of a graphene film suspended over a circular hole of the substrate.

• Journal of ILASS-Korea
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• v.15 no.2
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• pp.94-99
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• 2010

The object of this investigation is to study the thermal properties and spray characteristics of kerosene fuel in high temperature and pressure conditions. In order to investigate the thermal properties and spray characteristics, KIVA3 and SUPERTRAPP have been used at the same time. The thermal properties of kerosene has been calculated in high temperature and pressure condition using SUPERTRAPP. The study of spray characteristics has been conducted at both original properties of KIVA3 and calculated properties. The evaporation rate was increased in proportion to pressure when the calculated properties were used. However, the effect of pressure was not shown in the case of using original properties. So the calculated properties are more effective than original properties in high temperature and high pressure condition.

• Korean Journal of Human Ecology
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• v.7 no.1
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• pp.119-127
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• 1998

The purpose of this study was to evaluate thermal properties of pesticide protective clothing made of three different nonwoven fabrics which have barrier properties of pesticide. In order to assay the thermal properties of experimental clothing, thermal resistance measurements for clo value and thermographic assessment were conducted using a surface temperature controlled thermal manikin. The thermal manikin was dressed with underwear and experimental clothing. Air temperature in a climate chamber was kept at $28^{\circ}C$ and its humidity was 70% RH. Air velocity was controlled at less than 0.15m/s. Inner radient temperature was almost equal to the air temperature. The basic thermal insulation value(Icl) of underwear was 0.28 clo. The thermal properties of the experimental clothing were varied according to the type of material used in construction. The basic clothing insulation value for C1(spunbonded nonwoven fabric), C2(spunlaced nonwoven fabric), C3(SMS nonwoven fabric) were 0.705 clo, 0.725 clo, 0.738 clo respectively. The C3 experimental clothing made of SMS resulted in higher surface temperatures than the others with more yellowing spots being evident on the thermogram.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.46-51
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• 2008

In this study, evaluation system of the thermal properties of the exothermic agents was investigated. Exothermic agents property evaluation system was developed by metering variation of power supply. Thermal properties of exothermic agents was affected by material mixture condition of exothermic agents, however, it was not affected by temperature. It is possible to make various exothermic agents by means of regulating thermal properties which is based on property evaluation system of exothermic agents.