• Title/Summary/Keyword: 한대

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Experimental and Numerical Investigation of the Performance of Vertical Thermosyphon for Frozen Ground Stabilization (실험과 수치해석을 통한 동토지반 안정화용 수직형 열사이펀의 성능평가)

  • Lee, Jangguen;Lee, Chulho;Jang, Changkyu;Choi, Changho
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.45-56
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    • 2014
  • Frozen ground in cold region consists of an upper active layer and lower permafrost which is permanently frozen land. During the summer season, the air temperature is high enough to make the frozen ground melt, which causes the reduction of soil strength and thaw settlement. These phenomena result in structural instability, so it is necessary to apply frozen ground stability techniques. Thermosyphon is a closed natural two-phase convection device to maintain the ground temperature below $0^{\circ}C$ by extracting heat from the ground and discharges it into the atmosphere. Experimental and numerical investigation has been performed to estimate the effect of the refrigerant filling ratio in thermosyphon using R-134a refrigerant and the thermal conductance of the thermosyphon.

Distribution of Evergreen Broad-leaved Plants and Climatic Factors (한반도 상록활엽수의 지리적 분포와 기후요소)

  • 구경아;공우석;김종규
    • Journal of the Korean Geographical Society
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    • v.36 no.3
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    • pp.247-257
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    • 2001
  • The relationships between the distribution of 132 species, 61 genera evergreen broad-leaved trees and shrubs(EBTS) and climatic factors have discussed. The distributional patterns of EBTS were categorized into seven groups on the basis of the number of distributing sites, distributional attitudes and latitudes. Out of seven group. the cold-tolerant EBTS were common at groups I and II, along tilth Empetrum nigrum var. japonicum. Diapensia lapponics subsp. obovata of group III. However, the warmth-tolerant EBTS were rich at groups III. IV V, and VI The lower distributional limits of cold-tolerant EBTS in the groups I and UU decreased as one moves toward south. The upper distributional limit of warmth-tolerant EBTS in the groups III, IV and V decreased with increasing latitude. However. no clear distributional tendency is noticed in the groups VI and VII. The range of warmth-tolerant EBTS appear to show close relationship with the January mean temperature -4 $\^{C}$ and January mean minimum temperature -9$\^{C}$ than others. On the other hand, that of the cold-tolerant EBTS seem to respond well to the August mean temperature 19$\^{C}$ and August mean maximum temperature 26$\^{C}$ than others.

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옥수수 전분박을 이용한 식사료효모생산에 관한 연구

  • 성낙계;김명찬;윤미경;김종규;윤한대
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1976.10a
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    • pp.187.1-187
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    • 1976
  • 우리나라의 전분원료는 74년 이후 옥수수를 주로 사용함에 따라 부산물로써 폐기되는 전분박은 전국적으로 약 2,000M/T으로 추산된다. 이 전분박을 산당화처리하여 식전 및 가축, 양어사료제조를 목적으로 효모를 배양하는 실험을 하였다.(중략)

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새로운 조경수 -가문비나무

  • 김사일
    • Landscaping Tree
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    • v.81 no.7_8
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    • pp.4-9
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    • 2004
  • 소나무과(Pinaceae) 가문비나무속(Picea)에는 40여종의 나무들이 있으며 대부분이 지구의 북반구의 온대와 한대지방에 분포하고 있다. 우리나라에는 자생종으로 가문비나무, 풍산가문비나무, 종비나무 등이 있으며 가문비나무중에 구과(毬果)가 자갈색(마르면 암갈색)인 것을 붉은가문비, 풍산가문 비나무중에 가지에 털이 있는 것을 털종비나무로 분류하고 있다.(중략)

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