• Elastomers and Composites
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• v.32 no.5
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• pp.318-324
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• 1997

Since the rigid and continuous networks of high-purity silica(white carbon) were relatively transparent to microwaves, high purity silica coupled with microwaves using a zirconia susceptor at room temperature and it was then heated to its melting temperature. The low-purity silica, contained small amount of impurities, yielded greater microwave absorption owing to easy motion of the interstitial alkali ions and it was then heated to its melting temperature. X-ray diffraction patterns of the low-purity silica were broader than those of the high-purity silica due to higher concentration of non-bridging bond and more deformed random network structure. In the vulcanization process of whitened or coloured rubber compound which is employing low-purity silica(white carbon) as a reinforcing filler, vulcanizate could be obtained effectively by microwave heating energy.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.09a
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• pp.124-128
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• 2005

To produce a highly sensitive uncooled microbolometer, the development of a high-performance thermometric material is essential. In this work, amorphous vanadium-tungsten oxide was developed as a thermometric material at a low temperature of $300^{\circ}C$, and the microbolometer, coupled with the material, was designed and fabricated using surface micromachining technology. The vanadium-tungsten oxide showed good properties for application to the microbolometer, Such as a high temperature coefficient of resistance of over -4.0 $\%$/K and good compatibility with the surface micromachining and integrated circuit fabrication process due to its low fabrication temperature. As a result, the uncooled microbolometer could be fabricated with high detectivity over $1.0\;{\times}\;10^9\;cmHz^{1/2}/W$ at a bias current of $7.5\;{\mu}A$ and a chopper frequency of 10-20 Hz

• New & Renewable Energy
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• v.17 no.1
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• pp.1-6
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• 2021

Transparent conducting oxide (TCO) films have been widely used in optoelectronic devices, such as OLEDs, TFTs, and solar cells. However, thin films of indium tin oxide (ITO) have few disadvantages pertaining to process parameters such as substrate temperature and sputtering power. In this study, we investigated the requirements for using TCO films in silicon-based solar cells and the best alternative TCO materials to improve their efficiency. Moreover, we discussed the current status of high-efficiency solar cells using low-temperature TCO films such as indium zinc oxide and Zr-doped indium oxide.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.65-71
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• 2005

At present, Electronic industries push ahead to eliminate the Pb(Lead) -a hazardous material-from all products. Especially, we have performed to select the optimum standard composition of lead free alloy for the application to products for about 3 years from 2000. These days, we have the chance for applying to the mass-production. This project constructed the system for applying the lead free solders on consumer electronic products, which is one of the major products of the LG Electronics. To select the lead free solders with corresponding to the product features, we have passed through the test and applied with Sn-3.0Ag-0.5Cu alloy system to our products, and for the application to the high melting temperature composition, we secured the thermal resistance of the many parts and substrate and optimized the processing conditions. We have operated the temperature cycling test and the high temperature storage test under the standards to confirm the reliability of the products. On these samples, we considered the consequence of our decision by the operating test. For the long life time of the product, we have operated the temperature cycling test at $-45^{\circ}C\;-\;+125^{\circ}C$, 1 cycle/hour, 1000 cycles. Also we have tested the tin whisker growth about lead free plating on lead finish. We have analyzed with the SEM, EDS and any other equipment for confirming the failure mode at the joint and the tin whisker growth on lead free finish.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.1
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• pp.85-96
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• 1990

Simultaneous removal efficiencies of hydrophilic and hydrophobic gaseous pollutants are experimentally determined, and the macroscopic removal mechanism of pollutants in a dry scrubber is analyzed using the extended model of three phase equilibrium distribution of pollutant at high temperatures that can describe the different morphological conditions of adsorbent and water at varying relative humidities. For the simplicity, the inside of spray dryer is divided into three regions of ; (1) absorption, (2) three-phase equilibrium, and (3) adsorption, and the removal efficiencies of each pollutants at three regions are observed at different experimental conditions to estimate the effects of important parameters of dry scrubber. The laboratory experiments simulate the three regions of spray dryer with the temperature control and thus evaporation rate of water from the slurry particle. $SO_2$ as a hydrophilic gaseous pollutant and vinyl chloride as a hydrophobic toxic gas are selected for the future field application to soid waste incineration, and the two types of slurry are made of the two sorbents ; 10 wt.% $Ca(OH)_2$, and 10 wt.% NaOH. Result of temperature effect shows the height of absorption plus three-phase region is decreased as the operation temperature is increased, which results in the lower removal efficiency of $SO_2$ but higher removal for vinyl chloride in the adsorption region of dry scrubber. The removal efficiency of $SO_2$ is higher by NaOH slurry than by $Ca(OH)_2$ slurry due to the hygroscopic nature of NaOH, while the removal of vinyl chloride is higher in $Ca(OH)_2$ case. From the analysis of redults using three-phase equilibrium distribution model, the effective two-phase partition coefficients can be obtained, and the possible extention in the application of the three-phase equilibrium model in a dry scrubber design has been demonstrated.

• Journal of Ocean Engineering and Technology
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• v.16 no.2
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• pp.60-66
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• 2002

The remote measurement system(RMS) as a new experimental method is limited in its application to crack measurement at elevated temperatures because of the oxide layer on the specimen surface. Since TiAIN and Cr coating layers have a high resistance to oxidation and wear, this paper proposed a TiAIN and Cr coating technique for specimens to facilitate the measurement of crack growth behavior using RMS. To investigate the effects of the coating layer, tension and fatigue tests were carried out at room temperature and at $538^{\circ}C$. The test material was 1Cr-1Mo-0.25V steel which is widely used as a turbine rotor material. From the experimental results, it was found that the mechanical properties of the TiAIN and Cr coated specimens were similar to those of the substrate. Accordingly, the TiAIN and Cr coated layer had hardly any influence on the fatigue crack propagation.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.51-54
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• 2004

In this paper, the thermal and mechanical properties of elastic epoxy for the application of high voltage products were investigated. Glass transition temperature (Tg) of elastic epoxies cannot be found from room temperature to 20$0^{\circ}C$ by DSC (Differential Scanning Calorimetry). Weight reduction occurred at 285$^{\circ}C$ and 451$^{\circ}C$ according to a thermogravimeter. The first temperature was affected by addictives and the second by epoxies characteristic. Maximum tensile strain showed 28.3kgf/$\textrm{cm}^2$/$\textrm{cm}^2$ at 20% of mechanical stress in addictives 35 (phr). The SEM (Scanning electron microscope) micrograph of the fracture surface observed void and tearing of elastic epoxy at addictives 35 (phr). On the other side, the SEM micrograph of the rigid epoxy showed a broken trace.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.1
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• pp.54-60
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• 2011

Procedures for estimation of insulation thickness for a horizontal pipe for condensation control or personnel protection has been investigated, parallel to the previous work of a vertical wall case. Parameters include pipe diameter, emissivity, thermal conductivity, and operating temperatures. The results indicated that the surface emissivity plays a very important role in the design of insulation, specially for the case of high temperature application with low Bi. The effect of surface radiation in such case could be up to 65% of the total. Required insulation thickness for the surface temperature control increases as pipe diameter increases and as surface emissivity decreases. Adequate revision of specifications or standards to include newly invented insulation materials with high emissivity has been also suggested.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.265-271
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• 1998

High temperature wear behavior of plasma sprayed zirconia based coating sealing with zirconia sol were investigated for high temperature wear resistance application. The zirconia powders containing 2.5, 5.0, 7.5, 10.0 mol% of MoS$_2$, $Fe_2O_3$ for plasma spray were made by spray drying method. As-sprayed coating was sealed by zirconia-sol to fill up the pore and crack in coating. wear test were performed at temperature ranges from room temperature to 600$\circ$C. The microstructural changes of before and after sealing process were examined by SEM, XRD and EPMA. After sealing process, the porosity was decreased and micro-hardness was increased. The wear properties of coating after sealing process were improved by sealing of pores and cracks. The behavior of wear amount and coefficient of friction were same tendency to before sealing process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.116-119
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• 2007

The application of light weight materials, such as aluminum alloy, has been limited due of their poor formability. Especially, aluminum alloy tube has limited expansion capability at most 15% at room temperature. New manufacturing process, called hot air forming, is introduced to apply aluminum tube to the automotive suspension components which have complex shape and require high expansion ratio about 40%. The process is carried out at the elevated temperature above $500^{\circ}C$, so numerous material properties and process parameters related to the high temperature should be investigated and determined to get a sound product. In this study, the effect of thermal properties and forming parameters such as the temperature of tool, axial feeding and gas pressure are analyzed by using explicit finite element method.