• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.203-214
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• 2012

The physical environment of urban areas covered mostly by concrete and asphalt is the main cause of the urban heat island effect, primarily becoming apparent through increased land surface temperature. This study examined the effect of different urban land cover types on the land surface temperature using MODIS, Landsat ETM+ and RapidEye satellite data. As a result, the remote sensing based land surface temperature showed a marked difference according to the land use pattern in the case study of Ilsan new city. The high-rise apartment residential districts with less building-to-land ratio and higher green area ratio revealed lower land surface temperature than the low-story single-family housing districts characterized by relatively high building-to-land ratio and low green area ratio. From the view of climate zone and land cover types, there is a strong linear correlation between the impervious land cover ratio and the land surface temperature; the land surface temperature increases as the impervious built-up areas expand. In contrast, vegetation;water and shadow areas affect the decrease of land surface temperature. There is also a negative (-) correlation between NDVI and land surface temperature but the seasonal variation of NDVI can be hardly corrected.

• Carbon letters
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• v.1 no.1
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• pp.1-5
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• 2000

The effect of surface free energy on the positive temperature coefficient (PTC) of carbon black/thermoplastic resin composites was investigated. The thermoplastic resins such as EVA, LDPE, LLDPE and HDPE were used with the addition of 30 wt.% of the carbon black. The surface free energy of the composites was studied in the context of two-liquid contact angle measurements, i.e., deionized water and diiodomethane. It was observed that the resistivity on PTC composites Was greatly increased near the crystalline melting temperature, due to the thermal expansion of polymeric matrix. From the experimental results, it was proposed that the decrease of surface free energy induced by interactions between carbon black surfaces and polymer chains is an important factor to the fabrication of a PTC composite made of carbon black and polymeric matrix.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.11
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• pp.3063-3071
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• 1995

An experimental study has been carried out for the heat transfer and particle deposition during the Outside Vapor Deposition process. The surface temperatures of deposited layers, and the rates, efficiencies and porosities of particle deposition were measured. It is shown that the axial variation of the surface temperature can be assumed to be quasi-steady and that as the traversing speed of burner is increased, the deposition rate, efficiency and porosity increase due to the decreased surface temperature. As the flow rate of the chemicals is increased, both the thickness of deposition layers and the surface temperature increase. Deposition rate also increases, however, deposition efficiency decreases for tests done. Later passes in early deposition stage result in higher surface temperatures due to increased thickness of porous deposited layers, which cause the deposition rate, efficiency, and porosity to decrease.

• Journal of the Korean institute of surface engineering
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• v.38 no.1
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• pp.7-13
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• 2005

Bismuth thin films were prepared on glass substrate with RF magnetron sputtering and effects of substrate temperature on surface morphology and their electrical transport properties were investigated. Grain growth of bismuth after nucleation and the onset of coalescense of grains at 393 K were observed with field emission secondary electron microscopy. Continuous thin films could not be obtained above 473 K because of grain segregation and island formation. Hall effect measurements showed that substrate heating yields the decrease of carrier density and the increase of mobility. Resistivity of bismuth film has its minimum (about 0.7 x 10/sup -3/ Ωcm) in range of 403～433 K. Annealing of bismuth films deposited at room temperature was carried out in a radiation furnace with flowing hydrogen gas. The change of resistivity was not significant due to cancellation of the decrease of carrier density and the increase of mobility. The abrupt change of electrical properties of film annealed above 523 K was found to be caused by partial oxidation of bismuth layer in x-ray diffraction analysis.

• Journal of the Korean institute of surface engineering
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• v.41 no.5
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• pp.214-219
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• 2008

Indium tin oxide (ITO) films were deposited on PET substrate by RF superimposed DC magnetron sputtering using ITO (doped with 10 wt% $SnO_2$) target. Substrate temperature was maintained below $750^{\circ}C$ without intentionally substrate heating during the deposition. The discharge voltage of DC power supply was decreased from 280 V to 100 V when superimposed RF power was increased from 0 W to 150 W. The electrical properties of the ITO films were improved with increasing of superimposed RF power. In the result of cyclic bending test, relatively high mechanical property was obtained for the ITO film deposited with RF power of 75 W under DC current of 0.75 A which could be attributed to the decrease of internal stress caused by decrease in both deposition rate and plasma impedance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.551-556
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• 2000

We have investigated the effect of surface In composition with Si cell temperature on the In$_{0.1}$/Ga$_{0.9}$/As epilayers grown on GaAs substrates. The epilayers were grown by molecular beam epitaxy(MBE) method and were characterized by the pthotoreflectance(PR) measurements. The E$_{o}$ bandgap energies of In$_{0.1}$/Ga$_{0.9}$/As epilayers were observed at around 1.28 eV at room temperature, and the additional shoulder peaks appeared at the higher energies than E$_{o}$ with increase of Si doping concentrations. The intensity of the additional shoulder peak was decreased with lowering the measurement temperature and the peak disappeared with the increase of surface etching time. This results hows that In composition at surface of InGaAs epilayer is decreased with the increase of the doping cell temperature. We consider that the reason of the decrease of In composition at the surface should be due to In re-evaporation from the surface by radiation heat of Si doping cell.ell.ell.ell.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.73-79
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• 2021

The objective of this study is to prevent or decrease condensation on the surface of aluminum butterfly valves used in high humidity air conditions. We proposed a new valve with an anti-condensation device, a heat resistance medium, instead of a conventional valve. We, then, compared the surface temperature distribution between the proposed and conventional valves using experimental and analytical methods. The size of the evaluated valve is 100A and fluid conditions are 35℃/RH 75% in the air outside the valve and 5℃ in the cooling water inside the valve. The experimental results show that the surface temperature of the proposed valve is 23~42% higher than that of a conventional valve, thereby exhibiting an anti-condensation effect. As a result, we observed the complete prevention of condensation on a gear box mounted to the proposed valve, showing surface temperature distribution above the dew point temperature of air. The analytical results are in agreement with the trends in experimental results.

• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.16-22
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• 1995

The profiles of the heating temperature in three water vat temperatures (55, 66 and 77$^{\circ}C$) and the cooling temperature under the average ambient temperature of 3$^{\circ}C$ in 4 and 10cm depths from surface at the center of veneer bolts length showed similar patterns for Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata). The difference of these core temperatures of 10cm depth from surface varied proportionally with the increase of vat temperatures. The average heating time based on final core temperature of 6$^{\circ}C$ lower than vat temperature required about 14.5 hours in vat temperature of 55$^{\circ}C$ and 13.5 hours in vat temperature of 66and 77$^{\circ}C$. Each internal temperature of 4 and 10cm depths from surface started to decrease from the beginning of cooling and after about two hours.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.715-724
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• 2012

In this study, we simulated water temperature in the downstream according to withdrawal types of dam using EFDC model. Three scenarios were assumed as water was released from the surface layer, the middle layer, and the bottom layer at intervals of 10m depth. In case of the surface layer withdrawal, the water temperature rose from March and lowered gradually after it reached a peak in August. The middle and the bottom layers effluence temperatures were lower than the surface layer temperature by maximum $15.9^{\circ}C$(in July), but after September, temperature inversion appeared. It was advantageous for the surface layer withdrawal to decrease cold damage and fog in downstream area and was possible to the middle and the bottom layers withdrawal from August to September. However, the reliability of model should be improved by accumulating the real-time information of water temperature.

• Steel and Composite Structures
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• v.21 no.2
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• pp.429-442
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• 2016

The aim of this paper is to determine temperature and stress distributions in a ceramic based on Partially Stabilized Zirconia coated steel piston crown by using plasma spraying for improving performance of a marine diesel engine. Effects of coating constituent and thickness on temperature and stress distributions were investigated including comparisons with results from an uncoated piston by means of finite element method namely ANSYS. Temperature developed at the coated surface is significantly higher than that of the uncoated piston. The maximum stress components occur between bond coat and adjacent ceramic layer. Provided that coating thickness is constant as 0.5 mm, when numbers of layers increase, magnitude of the normal stress decrease about 34.1% on the base metal surface according to uncoated piston, but the base metal surface temperature of the steel piston increase about 13.1%.