• Title/Summary/Keyword: Cold Energy

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Realistic Large Break Loss of Coolant Accident Mass and Energy Release and Containment Pressure and Temperature Analyses

  • Kwon, Young-Min;Song, Jin-Ho
    • Nuclear Engineering and Technology
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    • v.29 no.3
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    • pp.229-239
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    • 1997
  • To investigate the realistic behavior of mass and energy release and resultant containment response during large break Loss of Coolant accident (LOCA), analyses are performed for Yonggwang (YGN) 3&4 nuclear power plants by using a merged version of RELAP5/CONTEMPT4 computer code. Comparative analyses by using conservative design computer codes are also peformed. The break types analyzed are the double-ended guillotine breaks at the cold leg and hot leg. The design analysis resulted in containment peak pressure during post-blowdown phase for the cold leg break. However, the RELAP5/CONTEMPT4 analyses show that the containment pressure has a peak during blowdown phase, thereafter it decreases monotonously without the second port-blowdown peak. For the hot leg break, revised design analysis shows much lower pressure than that reported in YGN 3&4 final safety analysis report. The RELAP5/CONTEMPT4 analysis shoos similar trend and confirmed that the bypass flow through the broken loop steam generator during post-blowdown is negligibly small compared to that of cold leg break. The low pressure and temperature predicted tv realistic analysis presented in this paper suggest that the design analysis methodology contains substantial margin and it can be improved to provide benefit in investment protection, such as, relaxing plant technical specifications and reducing containment design pressure.

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Study of oriental medical science documentory records of hiccup and neuropsychiatric aspect of hiccup (액역(呃逆)에 관한 한방정신의학적 고찰(考察))

  • Shim, Tae-Kyung;Jung, In-Chul;Lee, Sang-Ryong
    • Journal of Haehwa Medicine
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    • v.18 no.1
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    • pp.49-66
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    • 2009
  • 1. Hiccup is usually named as Hae yek, Hyel yek, Yel yek. 2. The cause of hiccup are stomach cold, rising of stomach fire, stagnation of vital energy and stagnationof phlegm, yang deficiency of spleen and kideny, deficiency of stomach-yin, or mental disorder due to the stagnation of phlegm, dyspepsia, depressed vital energy. 3. Vicera and Bowels related with Hiccup are lung, spleen, stomach, and heart. 4. The treatment of hiccup are dispel cold by warming the middle warmer due to stomach cold, expel the heat-evil to loose hollow-organ due to rising up of stomach yin, regulate vital energy and dissipate phlegm due to stagnation of vital energy and stagnation of phlegm, warm and recuperate both of spleen and kidney due to spleen and kidney yang deficiency, nourish the stomach to promote the production of body fluid due to deficiency of stomach yin. 5. Regarding neuropsychiatric aspect of hiccup, qi movement disorder was the main mechanism of disease and qi depression was the main cause. The prescriptions for neuropsychiatric hiccup were Mokhwangjogisan Pyunjakjunghyangsan, Daegwakhyangsan, and Haeaedan.

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Comparison of Brood Productions in the Cold-Treated Pairing vs. Not Cold-Treated Pairing in a Stenochronous Spider

  • Kim, Kil-Won
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.145-148
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    • 2009
  • To understand whether experience of cold season in reproductive behaviors in the adults of Amaurobius ferox, the paired adults of a female and a male were exposed under 'cold-treated environment' and 'not cold-treated environment', respectively. I investigated effects of the cold treatment on the brood production of A. ferox. In not cold treatment in which male-female pairs were formed in October at a temperature of $20^{\circ}C$ (${\pm}2^{\circ}C$) and continuously kept under not cold-treated environment, only 3 of 50 pairs successfully reproduced (reproduction was defined as the emergence of spiderlings). In cold treatment where individuals were kept in cold conditions for 3 months prior to pair formation, 57 out of 60 couples succeeded in reproducing. Females which did not experience the low temperature displayed strong aggressiveness toward males. This behavioral inhibition might the primary barrier to copulation of A. ferox that decrease following a period of low temperature. The reproductive inhibition might help the females to allocate the maximum amount of energy in a given environment to reaching the adult stage and to delay reproduction in unfavorable wintering conditions.

Local Enhancement Mechanism of Cold Surges over the Korean Peninsula (한반도 한파의 지역적 강화 메커니즘)

  • Lee, Hye-Young;Kim, Joowan;Park, In-Gyu;Kang, Hyungyu;Ryu, Hosun
    • Atmosphere
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    • v.28 no.4
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    • pp.383-392
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    • 2018
  • This study investigates synoptic characteristics of cold surges over South Korea during winter season (December-February). A total of 63 cold events are selected by quantile regression analysis using daily mean temperature observations from 11 KMA stations for 38 years (1979/80-2016/17). Large-scale pressure pattern during the cold surges is well characterized by high over Siberia and low over Aleutian regions, which elucidates cold advection over the Korean peninsula. However, the large-scale pattern cannot successfully explain the observed sudden decrease of temperature during the cold surges. Composite analyses reveal that a synoptic-scale cyclone developing over the northern Japan is a key feature that significantly contribute to the enhancement of cold advection by increasing pressure gradient over the Korean peninsula. Enhanced sensible and latent heat fluxes are observed over the southern ocean of Korea and Japan during the cold surges due to temperature and humidity differences between the near surface and the lower atmosphere over the ocean. The evaporated water vapor transported toward the center of the surface cyclone and condenses in the lower-to-middle troposphere. The released energy likely promotes the development of the surface cyclone by inducing positive PV near the surface of the heating region.