• Title/Summary/Keyword: Extremely cold condition

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Effects of the Nitrate and Phosphate Starvation on the Biosynthesis of Phospholipid and the Composition of Fatty Acids in Chlorella Chloroplasts (Chlorella 엽록체의 인지질 생합성 및 지방산조성에 미치는 Nitrate와 Phosphate 결핍효과)

  • 이점규
    • Journal of Plant Biology
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    • v.31 no.3
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    • pp.187-196
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    • 1988
  • Chlorella ellipsoidea were cultured in "cold" media starvated with the nitrate and phsophate sources. The effects of the nitrate and phsophate starvation on the biosynthesis of phospholipid and the composition of fatty acids in chloroplasts isolated from these cells were analyzed. The syntheses of phosphatidylcholine and phosphatidylinositol in the nitrate and phosphate starvation were similarly inhibited as compared with the control but phsophatidylethanolamine synthesis in the nitrate starvation was extremely lower than that in the phosphate starvation. The major fatty acids utilized in phospholipid formation within chloroplasts were palmitic acid and linolenic aicd. However, palmitic acid and stearic acid were dominant in the condition of the nitrate starvation. The levels of palmitic acid were enhanced 3-fold than that of the control. These results suggest that the biosynthesis of phospholipid and the composition of fatty acids were affected by the nitrate and phosphate starvation in the culture media.ure media.

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Design and Performance Tests of a Cryogenic Blower for a Thermal Vacuum Chamber (열진공 챔버용 극저온 블로워 설계 및 성능평가)

  • Seo, Heejun;Cho, Hyokjin;Park, Sungwook;Moon, Gueewon;Huh, Hwanil
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.11
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    • pp.1008-1015
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    • 2015
  • Thermal vacuum test should be performed prior to launch to verify satellites' functionality in extremely cold/hot temperatures and vacuum conditions. A thermal vacuum chamber used to perform the thermal vacuum tests of a satellite system and its components. A cryogenic blower is a core component of the gaseous nitrogen (GN2) closed loop thermal control system for thermal vacuum chambers. A final goal of this research is development of cryogenic blower. Design requirements of a blower are 150 CFM flow rate, 0.5 bara pressure difference, hot and cold temperatures. This paper describes the performance analysis of impeller by 1D, CFD commercial software, the design of the thermal protection interface between the driving part and the fluid part. The performance of the cryogenic blower is confirmed by test at the standard air condition and is verified by on the thermal vacuum chamber at the real operating condition.

Design and Performance Test of a Cryogenic Blower for Space Thermal Environment Simulation (우주 열환경 모사용 소형 극저온 블로워 설계 및 성능평가)

  • Seo, Heejun;Ahn, Sungmin;Huh, Hwanil
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.10
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    • pp.833-839
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    • 2013
  • Thermal vacuum test should be performed prior to launch to verify satellites' functionality in a harsh space environment which is represented by extremely cold temperatures and vacuum conditions. A thermal vacuum chamber which consists of a vacuum vessel, a pumping system, and a thermal control system are used to perform thermal vacuum tests of a satellite system and its components. A cryogenic blower is a core component of the closed loop thermal control system for thermal vacuum chambers. This paper describes the fan design of the cryogenic blower, the design of the thermal protection interface between the driving part and the fluid part, which were verified by thermal and structural analyses. The performance of the cryogenic blower is confirmed by similarity test on the test bench.