• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.734-741
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• 2016

Lily (Lilium davidii) is a high-yielding flowering plant. Besides roses and chrysanthemums, lily bulbs have long been used as food and in oriental medicine. However, the usage and value of cut lily bulbs has not been recognized. A bulb whose yield has been decreased is called a waste bulb, and a large amount of such bulbs is discarded every year. In this study, the functionality of waste bulbs from cut lilies was investigated to explore their potential use as a value-added product. We divided lily bulbs into two groups, one group with six varieties of new bulbs (Medusa, Siberia, Woori Tower, Yelloween, Le Reve, and Morning Star) used for cultivation and the other group with six varieties of waste bulbs (Medusa, Siberia, Woori Tower, Yelloween, Sorbonne, and Sheila). Physiological activities (${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl: DPPH) and 3-ethlbenzthiazolne-6-sulfonic acid (ABTS) radical scavenging capability and tyrosinase inhibiting activity), the amount of total as well as eight individual phenolic compounds (chlorogenic acid, epicatechin, rutin hydrate, p-coumaric acid, kaempferol 3-O-${\beta}$-rutinoside, phloridzin dihydrate, myricetin, and quercetin), and total flavonoid content were measured in the bulbs by high performance liquid chromatography. We detected high amounts of total phenol and total flavonoid as well as high DPPH and ABTS radical scavenging ability. More tyrosinase inhibiting activity was detected in the new bulbs than in the waste bulbs. However, both the new and waste bulbs showed a higher inhibitory activity than the standard (100 ppm ascorbic acid). Although the content of phenolic compounds differed among varieties, under the conditions of the experiment, the most abundant phenolics were epicatechins, followed by chlorogenic acid, and rutins. Overall, the waste bulbs had a higher content of these compounds than the new bulbs. Based on these results, we concluded that bulbs from cut lilies could be used as functional foods in the future and farmers could expect economic gain from the hitherto neglected waste bulbs.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.507-516
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• 2009

In cases of high-level radioactive waste repositories, heat load is apparent by radioactive waste decay. The safety of a waste repository would be influenced by changing circumstances caused by heat transfer through rock. Thus, a ventilation system is necessary to secure the waste repository. The first priority for building an appropriate ventilation system is completing a computer simulation research with thermal rock properties and a heat transfer coefficient. In this study, the heat transfer coefficient in KURT was calculated using the measurement of inner circumstance factors that include dry bulb and wet bulb temperature, rock surface temperature, and barometric pressure. The heater that is 2 m in length and 5 kw in capacity heats the inside of rock in the research module by $90^{\circ}C$. As a result of determining the heat transfer coefficient in the heating section, the changes of heat transfer coefficient were found to be a maximum of 7.9%. The average heat transfer coefficient is approximately 4.533 w/$m^2{\cdot}K$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.573-577
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• 2013

Heat pumps come into wide use because high energy efficiency can be obtained and diverse heat sources like geothermal heat, waste heat and air are available. It is necessary for an air source heat pump to defrost in order to remove frost on the surfaces of an outdoor heat exchanger. It is impossible for continuous heating if reverse cycle operation is used as defrosting method, furthermore it causes the degradation of COP. In this study an fin-tube heat exchanger with three rows was used as an outdoor coil. One row among three rows of the heat exchanger was used like a condenser in order to remove frost on it, the others were used as evaporator to accomplish continuous heating. Each row was switched in order from a condenser to an evaporator in specified time interval. Tests were carried out during minimum 180 minutes at the defrost-heating test condition(dry bulb temperature $2^{\circ}C$, wet bulb temperature $1^{\circ}C$) described in KS C 9306. Time-averaged COP was about 20% higher than that of conventional defrosting method.