• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.5
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• pp.352-359
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• 2003

The present study has been conducted for manufacturing MPCM (microencapsulated phase change material) slurry with in-situ polymerization and proving their applicabilities for tooling system. The surface of MPCM is composed of melamine, while tetradecane, paraffin wax, is centered in the MPCM. The produced capsules are observed by the optical microscope and SEM for superficial shapes. Their thermal properties are measured by DSC. Their size distributions are observed by FA particle analyzer. A narrow size distribution from 1 to 10 ${\mu}{\textrm}{m}$ with 5 ${\mu}{\textrm}{m}$ of average diameter was observed. Melting temperature was 6.7$^{\circ}C$. The durability of MPCM was tested with various types of pump such as centrifugal, peristaltic, and mono pumps. During 10000 cycles the fraction of broken capsules was smaller than 6% for the centrifugal and peristaltic pumps, while bigger value of 8% for the mono pump. A cooling system, which adopted MPCM slurry as a media for transporting cold thermal energy, was designed to investigate the performance of the MPCM. The discharging times of 10 and 20 wt% MPCM slurry were lasted up to 105 and 285 minutes longer, respectively, than the water cooling system.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.4
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• pp.175-183
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• 2005

The present study has been conducted for manufacturing MPCM (microencapsulated phase change material) slurry with in-situ polymerization and proving their applicabilities for cooling system. The tetradecane as a core material of MPCM is coated with melamine. The produced capsules are observed by the optical microscope and SEM for superficial shapes and analysed their properties by DSC and particle size distribution by FA particle analyzer. It is found that narrow size distribution in 1 to $10{\mu}m$ is resulted in $5{\mu}m$ of average diameter and $9^{\circ}C$ melting temperature. The durability of MPCM capsules is tested with various types of pumps such as centrifugal, peristaltic, and mono. For the centrifugal and peristaltic pumps the breakage fraction of the capsules is resulted within $6\%$ during 10,000 cycles, while the mono is over $8\%$. The cooling system, which has adopted MPCM slurry as a medium for transporting cold thermal energy, is designed to investigate the performance of newly developed coolant. The discharging times of cold energy in circulating 10 and $20wt\%$ MPCM slurry are lasted to 105 and 285 minutes, respectively.

• Resources Recycling
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• v.25 no.3
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• pp.43-48
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• 2016

Cement manufacturing plant uses various kinds of industrial/municipal waste. The waste contains considerable amount of potassium, chlorine and small amount of heavy metal. Many researches were performed to fabricate valuable resources from the waste. In this study, various methods, which dissolves and crystallizes potassium/chlorine to extract potassium chloride, were experimented. Especially amount of water, slurry temperature, and stirring time were controlled. Then kind of heavy metal and content of potassium chloride were analyzed. The yield of potassium chloride increased, as the amount of water for slurry increased but it increased slightly, when the water content was over 200%. The yield tended to increase, when the temperature of slurry was over a certain point. The yield did not increase in case of over 10 minutes stirring time. The kind and content of heavy metal in potassium chloride were various according to stirring time. The main heavy metals were Pb, Cu, and $Cr^{6+}$.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.1-6
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• 2012

The polishing of silicon wafers has an important role in semiconductor manufacturing. Generally, getting a flat surface such as a mirror is the purpose of the process. The wafer surface roughness is affected by many variables such as the characteristics of the carrier head unit, operation, speed, the pad and slurry temperature. Optimum process conditions for experimental temperature, pH value, down-force, slurry ratio are investigated, time is used as a fixed factor. This study carried out a series of experiments at varying platen, chuck rpm and oscillation cpm taking particular note of the difference between the rpm and the affect it has on the surface roughness. In this experiment determine the optimum conditions for polishing silicone wafers.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.984-989
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• 2009

The present study has been conducted to predict the temperature distribution in the core of the scraper type ice generator. The analytic model was simplified as the flow in the annular type cylinder, which had an inside wall moving in axial direction due to the rotation of screw and a fixed outside wall. The governing equations were arranged by the method of separation of variables. The results corresponded to the exact solutions of the Bessel function. The qualitative results such as general characteristics of heat transfer in annulus flow from outer cylinder wall to the inside wall were obtained. However the amount of the heat transfer was underestimated as low as $1/5{\sim}1/6$ of the designed value.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.70-71
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• 2005

The material that is both conductive in electricity and transparent to the visible ray is called transparent conducting thin film. It is investigated the performance of ITO-CMP process using commercial silica slurry with the various conditioning temperatures by control of de-ionized water (DIW). Removal rate of ITO thin film was improved after CMP process after pad conditioning at the high temperature by improved exclusion of slurry residues in polishing pad..

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.431-432
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• 2006

In this study, the effect of the temperature of magnesium slurry was investigated by mechanical stirring method. The evaluations of rheological behavior of AM50A magnesium alloy were measuring of viscosity and microstructures in the semisolid state. The apparent viscosity was investigated at continuous cooling rate using a concentric cylinder viscometer. Measurement of viscosity measures torque that act to stirrer rotating in slurry doing continuous cooling using torque-meter and expressed by POWER-LAW. Microstructures were observed after mechanical stirring that enforce time at steady state temperature of solid fraction.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.3
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• pp.12-23
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• 2007

Frequently spraying of natural starch slurry onto the formed wet web has been adopted to improve properties of paperboards. This conventional starch spraying technique, however, becomes less effective in strength improvement. In this study the effects of various factors including wet web dryness, quantity of starch slurry sprayed, and drying temperature on paperboard properties were investigated. Migration of starch granules into the webs appeared to cause a reduction in plybond strength when the web dryness was lower than this level. Wet webs should contain enough water to swell the starch granules, and at the same time they should be heated to a temperature high enough for complete cooking of the sprayed starches to occur. This suggested that preheating of the wet web can be employed to improve the plybond strength.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.28-35
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• 2015

In this study, the mechanisms on ultrasonication enhanced metals extraction were investigated compared with the conventional washing technique. We hypothesized the mechanisms on enhanced extraction of ultrasonication: ultrasonication increased the temperature of soil slurry and decreased average particle size of soil due to breakdown of soil aggregate. Actually, the ultrasonication increased the temperature of soil slurry to $60^{\circ}C$ in this study, and the increase in the temperature enhanced the metal extraction to 15-20% even in the conventional simple mixing. The conventional washing technique decreased average size of soil particles because of breakdown of soil aggregate, and the ultrasonication decreased the size more than that of washing. The breakdown of soil aggregate improved the contact between metals and washing agent, which enhanced the extraction of metals in the ultrasonication. Therefore, we concluded that the main mechanisms of ultrasonication are increase in the temperature and breakdown of the soil aggregate. Finally, the ultrasonicaiton increased the extractability of metals upto 40% compared to conventional washing technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.88-88
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• 2003