• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4329-4337
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• 2022

Jet impinging device is designed for decay heat removal on horizontal fuel rods in a low temperature heating reactor. An experimental system with a fuel rod simulator is established and experiments are performed to evaluate water film covering capacity, within 0.0287-0.0444 kg/ms mass flow rate, 0-164.1 kW/m² heating flux and 13.8-91.4℃ feeding water temperature. An effective method to obtain the film coverage rate by infrared equipment is proposed. Water film flowing patterns are recoded and the film coverage rates at different circumference angles are measured. It is found the film coverage rate decreases with heating flux during single-phase convection, while increases after onset of nucleate boiling. Besides, film coverage rate is found affected by Marangoni effect and film accelerating effect, and surface wetting is significantly facilitated by bubble behavior. Based on the observed phenomenon and physical mechanism, dry-out depth and initial dry-out rate are proposed to evaluate film covering potential on a heating surface. A model to predict film coverage rate is proposed based on the data. The findings would have reliable guide and important implications for further evaluation and design of decay heat removal system of new reactors, and could be helpful for passive containment cooling research.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.3
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• pp.215-218
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• 1996

This study examines the possibility of early production of forage rape (cv. Akela and Velox) in the period of wintering. Bolting date was Feb. 2 to Feb. 9 in PE film house culture by non-heating and Mar. 3 to Mar. 12 in open field culture. And flowering date was Feb. 24 to Mar. 3 in PE film house culture by non-heating, so it was 30~50 days faster than the open field culture of Apr. 17 to Apr. 22. Fresh matter yield was 8, 356~4, 887 kg/10a in PE film house culture by non-heating, so it was 1, 431~1, 603 kg/10a yield increase than in the open field culture of 7, 253~7, 456 kg/10a Dry matter yield was 953~963 kg/10a in PE film house culture by non-heating, so it was 71~284 kg/10a yield increase than in the open field culture of 669~892 kg/10a.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.578-583
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• 2008

Korea which has change of clear season is using unique heater by the name of On-dol being invented since ancient times. Floor-heating device has no radiator, and generates no noise and dust. It can obtain satisfied heating sense than other heating system in low room temperature. And also it is a pleasant system that equals bottom and top temperature in a room. The purpose of this study is to develop the Floor-heating device using pulsating heat pipe. It propose floor-heating device using pulsating heat pipe of the dry process which alternative polyethylene pipe(low XL pipe) that is used widely to existent floor heating system and produce pilot Experiment and analyzed operation condition and performance of most suitable. In this study, main purpose is to develop floor-heating system using pulsating heat pipe by finding an optimum working condition according to changing ratio and evaluating a performance.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.3
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• pp.500-507
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• 2008

Hot air drying is a method that let moistures evaporate by heat exchange between heating air and dry target. This way is dominating more than about 70% of dryers that the use extent is wide fairly, and is established in domestic than dryer that use conduction or radiation etc. Most of research about drying had been emphasized in size of device through analysis for these dry phenomenon plain, heating topology, and aspect of form and so on by dry target's special quality, and research about device development or waste heat withdrawal technology in energy utilization efficiency side is slight real condition. Therefore, in this study, Investigated numerically about thermal efficiency elevation that is leaned against as that change the temperature of inlet and outlet in heat exchanger of the hot air drying tower.

• Journal of Korean Association for Spatial Structures
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• v.5 no.3 s.17
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• pp.26-32
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• 2005

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.14 no.1
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• pp.48-72
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• 1985

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.659-663
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• 1998

Mook is a traditional Korean food made from the sediment of mungbean, cowpea, buckwheat or acorn. The air-dried sediment of cowpea(6~9%, dry basis) was heated to 80~95$^{\circ}C$ by continuous(method A) or instantaneous(method B) heating method and held at that temperature for 20min and then cooled at 15$^{\circ}C$ for 3hrs. The optimum deformation rate for the measurements of hardness and cohesiveness of cowpea mook by Instron Universal Testing Machine was 55~65% by method A and 60~70% by method B. The hardness of mook made by method A was the highest at heating temperature of 9$0^{\circ}C$, whereas that by method B was linearly decreased as the heating temperature increased at all concentrations. The mook made by method B had higher cohesiveness than that by method A. The ratio of cohesiveness to hardness was also higher in mook made by method B.

• Journal of the Korea Institute of Building Construction
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• v.16 no.3
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• pp.193-199
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• 2016

This study is a research about performance of fireproof board using industrial waste such as oyster shell and dry process bottom ash through the heating test and conclusions were obtained as follows. Test samples show back side temperatures as follows : in $300^{\circ}C$, $103.1{\sim}125.1^{\circ}C$, in $600^{\circ}C$, $201.1{\sim}210.1^{\circ}C$, in $900^{\circ}C$, $249.2{\sim}276.9^{\circ}C$. In the test, temperature increases of specimens of fireproof board are kept at certain temperatures hence it could be concluded that the specimens withstand high temperatures. According to the test, it could be concluded that fireproof board made by smaller particles shows better performance up to $600^{\circ}C$ while at higher temperatures, fireproof board made by bigger particles shows better performance. It is estimated that fireproof board made by particles of bigger size has more pore structure and it delays heat conduction.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.70-74
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• 1974

The round muscle of Korean cattle and squid muscle were cooked with various methods which were followed digestibility test by use of pepsin in-vitro, determination of amino nitrogen in the course of digestion procedure by using Formol method (AOAC) and influence of ether treatment for preminary test also examined. The results obtained were summarized as follows: 1. The order of digestibility values were demonstrated as follows: In case of beef, it was autoclaving, frying, raw, freezing, roasting, boiling and in case of squid muscle, it was raw, autoclaving, boiling, freezing, dry heating and roasting. 2. The amounts of amino nitrogen for beef and squid muscle were increased in proportion to digestibility value. 3. There were no significances in the digestibility between treating with ether and none of any treatment of beef and squid muscle in raw condition.