• Journal of the Korean Solar Energy Society
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• v.21 no.1
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• pp.83-91
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• 2001

The heat transfer experiment in a pilot scale latent heat storage tank as a solar energy storage system for the hot water supply was carried out. The latent heat storage tank was consisted of three parts; Outer shell for hot water from solar collector, PCM storage vessel in the middle of the tank and immersed coil in the PCM vessel for hot water recovery. The heat storage tank has the dimension of 115 cm in height and 32 cm outside diameter. Paraffin wax (m.p = 55.4C) and sodium acetate trihydrate (m.p = 58 C) were employed as the PCM this study. Experimental variables were inlet temperature and flow rate of the hot water for heat storage stage and cold water for heat recovery stage. Temperature profiles, heat transfer coefficient and the efficiency of heat storage $(Q/Q_{max})$ and heat recovery $(Q/Q_{max})$ were determined for the paraffin wax and inorganic salt respectively.

• Food Science and Preservation
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• v.5 no.2
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• pp.119-122
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• 1998

This study was conducted to blow the effect of postharvest physiological changes on garlic quality according to its ecotypes and storage temperatures. The changes of water, total soluble solids, crude stein, md total fructans were measured and the rates of respiration and sprouting were analyzed during storage at 20$^{\circ}C$ and 30$^{\circ}C$. The decrease of water content and the increase of total soluble solids were reversely appeared during garlic storage. The crude protein content was gradually increased during storage but total fructan content was decrased. The respiration late was maximized at 60days after storage and the spouting rate was gradually increased. In the aspect of ecotypic characteristics, the water content, fructan content and sprouting rate were higher in 'Namdo' cultivar than those of southern type. The high storage temperature (30$^{\circ}C$) controlled spouting and loss of fructan, and it was effective to maintain the garlic quality.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.1
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• pp.32-36
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• 2009

The ice storage system uses water for low temperature latent heat storage. However, a refrigerator capacity is increased and COP is decreased due to supercooling of water in the course of phase change from solid to liquid. This study investigates the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N$) of $20{\sim}25wt%$ as a low temperature latent heat storage material. The results showed that the phase change temperature and the specific heat is increased and the supercooling degree is decreased as the weight concentration of TMA increased. Especially, the clathrate compound containing TMA 25 wt% has the average phase change tempera ture of $5.8^{\circ}C$, the supercooling degree of $8.0^{\circ}C$ and the specific heat of 3.499 kJ/kgK in the cooling process. This can lead to reduction of operation time of refrigerator in low temperature latent heat storage system and efficiency improvement of refrigerator COP and overall system. Therefore, energy saving and improvement of utilization efficiency are expected.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.681-688
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• 2006

This study investigates the dynamic response characteristics of a structure impacted by a high speed projectile. The impact of a 300 kg projectile on a water storage tank is simulated by the general purpose computer codes ANSYS and LS-DYNA. Several methods to simulate the impact are considered and their results are compared. Based upon this, an alternative impact analysis method that is equivalent to an explicit dynamic analysis is proposed. The effect of fluid on the responses of the tank is also addressed.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.73-79
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• 2015

In this study, a thermal storage performance and characteristics of daily operation were investigated when the air and the liquid were heated simultaneously by a hybrid solar air-water heater that can make hot water as well as heated air. The hybrid solar air-water heater is kind of a flat plate solar collector that can make hot water and heated air by installing air channel beneath absorber plate of traditional flat plate solar collector for hot water. As a result of daily operation, maximum water temperature reached in a thermal storage was shown $44^{\circ}C$ on 73kg/h of air mass flow rate and about $40^{\circ}C$ on 176kg/h of air mass flow rate. Thus, the necessity of heating water in thermal storage by operating only liquid side was confirmed when the temperature of liquid in thermal storage is lower than we need. In case of efficiency investigated on daily operation, the thermal efficiency of the liquid side was decreased with increment of the inlet liquid temperature and decrement of the solar radiation, but efficiency of the air side was increased with increment of inlet liquid temperature difference as the traditional solar air heater. Total thermal efficiency of the collector was shown from 65.85% to 78.23% and it was decreased with increment of the inlet liquid temperature and decrement of solar radiation same as the traditional system.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.202-202
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• 2011

Performance of the raw water-source heat pump system with a thermal storage tank has been analyzed in winter season. The raw water is transferred through the multi-regional water supply system from Han river. Raw water is large temperature difference resource compared with groundwater. Although the raw water temperature drops to $0.6^{\circ}C$ due to the heavy snowfall and the severe cold in late January and early February, 2010, the system has been normally operated without any trouble this winter. The unit COP and system COP considered all pump power consumption were estimated based on the second-by-second data of the all sensors. The monthly averaged unit COP and system COP are 3.37 and 2.76 respectively with $1.4^{\circ}C$ of raw water in January, 3.55 and 2.89 with $1.6^{\circ}C$ raw water in February, 3.82 and 3.15 with $5.4^{\circ}C$ raw water in March. The performance of the system are increased with raw water temperature, and the COPs are higher than the water-to-air heat pump system using relatively high temperature raw water from Daecheong reservoir because the water-to-water system was operated on the full load condition and was stopped when the thermal storage tank was full of the high temperature water.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.618-623
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• 2004

This paper has dealt with the heat storage characteristics of gel type micro size latent heat storage material slurry. The heat release operation to the gel type micro size latent heat storage material slurry was carried out using hot air bubbles by direct contact heat exchange. This experiment was carried out using phase change material of n-paraffin so the heat release amount is higher than cold water system. The parameters of this experiment were concentration of latent heat phase change material, height of heat release bath and inlet velocity of hot air. The main results obtained are as follows : (1) The effect of concentration of latent heat phase change material dispersed with water is very affective to the direct contact heat exchange between hot air and gel type micro size latent heat storage material slurry. (2) It is clarified that the most effective concentration of latent heat phase change material dispersed with water exists around 20mass% at this type of direct heat exchange model experiment.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2471-2475
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• 2007

Clathrate compound is the material that host in hydrogen bond forms cage and guest is included into it and combined. Crystallization of hydrate is generated at higher temperature than that of ice from pure water. And physical properties according to temperature are stable and congruent melting phenomenon is occurred without phase separation. But clathrate compound still had supercooling problem occurred in the course of phase change and supercooling should be minimized because it affects efficiency of equipment very much. Therefore, various studies on additives to restrain this or heat storage methods are needed. In this study was investigated the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N)$ of 20${\sim}$25 wt% as a low temperature latent heat storage material. And ethanol$(CH_3CH_2OH)$ was added and its cooling characteristics were studied experimentally to restrain supercooling of TMA-water clathrate compound.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.534-539
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• 2008

This study investigated the effects of pretreatment and storage conditions on the properties of stored chestnuts. Effects on chestnuts of refrigerated storage (RNT) and frozen storage (FNT) with no pretreatment, frozen storage after oxalic acid treatment without blanching (FON) and with blanching (FOB) were examined. Water binding capacity, swelling power, solubility, and viscosity of the starch produced from RNT, FNT, and FON were similar to those of the starch produced from control (CON). FOB showed significant differences in these properties from CON. Textural properties of starch gels prepared from stored chestnuts except FOB also were very similar to those of CON starch gels. The sensory characteristics of steamed FON and FNT were similar to those of steamed CON except in brown color and hardness. Steamed FNT tended to have higher brown color and lower hardness than steamed FON. Steamed RNT showed significant differences in all the sensory properties except in hardness and cooked chestnut flavor. Steamed FOB was significantly higher than steamed CON in water release and off-flavor. Among the storage conditions examined, frozen storage with oxalic acid treatment is recommended for the long-term storage of chestnuts.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.75-87
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• 2012

We investigated the physicochemical properties, pasting characteristics on the rapid visco analyzer, dough characteristics on a mixograph, product characteristics, and attributes of color and hardness of products made from a wheat bagel premix and rice bagel premix according to storage period and temperature. The pH and moisture content of stored rice bagel premix and wheat bagel premix, significantly decreased, depending on the storage temperature and time. The average of water retention capacity, alkaline water retention capacity, sedimentation value, and pelshenke value all significantly decreased temperature increases and increasing storage time. he initial pasting temperature and breakdown depending on the storage temperature and time showed a significant difference, but peak viscosity and setback with increasing storage time and temperature were not significantly different. The initial pasting temperature did not significantly affect the rice bagel premix. The midline peak time and band at 8 min of mixing time of the wheat bagel premix and rice bagel premix did not differ significantly. In product attributes, the cost of wheat bagel premix rice bagel premix and the L, a, and b value in color of wheat bagel premix showed significant difference. The hardness of wheat bagel premix according to storage time and the hardness of rice bagel premix depending on storage temperature significant difference. Therefore, storage time and temperature of wheat bagel premix and rice bagel premix and does not show significant differences. merchant can get regular and consistent, it is expected to lead to the promotion of rice consumption. Futhermore, research on better method to improve it's characteristics instead of wheat bagel premix is expected to.