• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.7
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• pp.317-323
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• 2001

We investigated the stability of cryocooler-cooled high-temperature superconducting (HTS) coils by using a computer program based on FEM. In this study, the current at which "thermal runaway" occurs, which depends on the relationship between the cooling power of the cryocooler and the heat generation in HTS coils, was adopted as a stability criterion of cryocooler operating HTS coils. It was shown that cryocooler-cooled HTS coil was stable in operating current above the critical current from the numerical analysis results by HTS model coil. And also, if we efficiently remove the heat generation from HTS coils by potimizing heat drain, the ramp-rate limitation can be mitigated because the effect of AC loss by the current rise was too small. Furthermore, in the case of pulsed operation; the HTS model coil is ramped from zero to the peak value in one second and back to zero current in one second, such as the operation of SMES device, the peak value of poerating current is 1.5-2 times greater than that of the thermal runaway current.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.59-65
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• 2016

MVR evaporation is a method of pressurizing the evaporating steam to raise its temperature with an electric compressor instead of burning fuel and reusing the heat source through the embraced heat exchanger to minimize energy use. MVR desalination system with wind power uses varying wind power instead of stable electricity and can flexibly control the volume of fresh water production. The present study introduces the design, construction and operation of a MVR desalination system of 30ton/day capacity. Experimental results, MVR compression ratio is higher than 1.5, temperature difference of the main heat exchanger is $5{\sim}7^{\circ}C$. This value shows the same performance as the designed value.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.47-52
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• 1986

A heat-labile enterotoxin and no heat-stable enterotoxin producing($LT^+ST^-$) plasmid (110 kilobases in size) was isolated from an enterotoxigenic Escherichia coli of human strain O15:H11 and used for analysis of the $LT^+$ deoxyrionucleic acid region using recombinant DNA technology. A DNA segment containing the $LT^+$ DNA region which was one restriction endonuclease BamHl fragment(6.2 kb in size) was joind to a small multicopy plasmid, pUC9. E. coli K-12 strain, JM103 harboring the chimeric plasmid produced greater amounts of LT than did the enterotoxigenic E. coli O15:H11 strain. The BamHl fragment was further digested with various restriction endonucleases and contained no HindIll restriction site which is an essential in $LT^+ST^+$ plasmid. The detailed DNA sequencing of this $LT^+ST^-$ plasmid is required.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.3
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• pp.177-182
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• 2000

The effects of betatizing and aging temperatures on the martensitic transformation characteristics in an Cu-13.4wt%Al-4.2wt%Ni single crystal have been studied. Microstructures show that the specimen betatized above $800^{\circ}C$ has only ${{\beta}_1}^{\prime}$ martensite while the specimen betatized of below $700^{\circ}C$ has two phases i.e., ${{\beta}_1}^{\prime}+{\gamma}_2$ When betatizing temperature increase from $600^{\circ}C$ upto $900^{\circ}C$, Ms and As temperatures decrease due to the dissolution of which ${\gamma}_2$ phase depletes Al content in the matrix thereafter makes the both Ms and As temperatures significantly increased. Ms and As temperatures of the specimen aged at $200^{\circ}C$ are relatively stable but those of the specimen aged at $300^{\circ}C$ are shifted rapidly with aging time, especially within the first 30min.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.726-734
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• 1996

This study was carried oui to find a proper heat storage material and iris container for the thermal energy recovery system of a vehichle. For this purpose, various phenomenon during phase change from solid to liquid and vice versa for three kind material, octahydrate barium hydroxide, naphthalene and acetamide, are experimentally investigated. Also three type material such as pyrex glass, polyethylene and cupper are tested the feasibility as being a container of heat storage material. From this experimental results, $Ba(OH)_2{\cdot}8H_2O$ showed high possibility as good storage media with condition of long life cycle and stable phase change, and cupper was found out as proper container of $Ba(OH)_2{\cdot}8H_2O$.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.117-122
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• 1992

Tom coagulated with $CaCl_2$ was used to make high-Ca soy milk, named tofu milk. Physicochemical analysis of regular soy milk and tofu milk adjusted at various pH and/or heat-treated was carried out. Unheated and heat treated tofu milk kept stable conoldal state at pH 8. The solubility of soy milk was low at pH 4 but increased gradually at higher pH, while mat of tofu milk was almost unchanged between pH 4 and pH 7 but increased rapid1y above pH 8. At pH 8, the viscosity of tofu milk was almost the same as soy milk, while mat of heat-heated tofu milk was much higher man that of soy milk. Especially, steamed tofu milk seemed to be a thick paste unable to drink, but autoclaved tofu milk was suitable to drink. Phytic acid content of tofu milk was somewhat lower man mat of soy milk.

• KSBB Journal
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• v.17 no.4
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• pp.345-349
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• 2002

The adsorption of the antimicrobial compounds(AMCs) and their heat-resistance were investigated for the packaging film manufacture, wherein, the antimicrobial compounds were adsorbed on a silica component. The naturally source antimicrobial compounds were produced by methylotropic actinomycetes strains MO-16 and MO-17, extracted with ethylacetate. Antimicrobial compounds adsorbed on water-soluble silica had retained activity against Gram(+) and the Gram(-) bacteria after heat treatment at 150$\^{C}$ for 5min. The benzoic acid showed strong antimicrobial activity to fungi and was stable to heat treatment. The combination of antimicrobial compound plus benzoic acid was synergistic against test strains. Therefore, we estimated that the water-soluble silica is suitable for the packaging film manufacture as a adsorbent of the antimicrobial compounds.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.704-710
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• 2000

Metal electrode materials for plasma display panel should have low electrical resistivity in order to maintain stable gas discharge and have fast response time. They should also hae good film uniformity adhesion and thermal stability. In this study Cr/Cu/Cr metal electrode structure is formed by DC magnetron sputtering. Cr and Cu films were deposited on ITO coated glasses with various DC power density and main pressures as the major parameters. After metal electrodes were formed a heat treatment was followed at 55$0^{\circ}C$ for 20 min in a vacuum furnace. The intrinsic stress of the sputtered Cr film passed a tensile stress maximum decreased and then became compressive with further increasing DC power density. Also with increasing the main pressure stress turned from compression to tension. After heat the treatment the electrical resistivity of the sputtered Cu film of 2${\mu}{\textrm}{m}$ in thickness prepared at 1 motor with the applied power density of 3.70 W/cm$^2$was 2.68 $\mu$$\Omega$.cm With increasing the main pressure the DC magnetron sputtered Cu film became more open structure. The heat treatment decreased the surface roughness of the sputtered Cr/Cu/Cr metal electrodes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.83-85
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• 2011

This study investigated the results of insulation heat curing method using double layer bubble sheet in concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that concrete was protected from early freezing by remaining between 7℃ and 3℃ even in case outside temperature drops -7℃ below zero until the 3d day from piling. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.25-28
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• 2009

This study investigated the results of insulation heat curing method using double layer bubble sheet in slab concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that slab concrete was protected from early freezing by remaining between 5 and $l0^{\circ}C$ even in case outside temperature drops $-11^{\circ}C$ below zero until the 4nd day from piling. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.