• 제목/요약/키워드: Small Plant

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Widespread Occurrence of Small Inversions in the Chloroplast Genomes of Land Plants

  • Kim, Ki-Joong;Lee, Hae-Lim
    • Molecules and Cells
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    • 제19권1호
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    • pp.104-113
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    • 2005
  • Large inversions are well characterized in the chloroplast genomes of land plants. In contrast, reports of small inversions are rare and involve limited plant groups. In this study, we report the widespread occurrence of small inversions ranging from 5 to 50 bp in fully and partially sequenced chloroplast genomes of both monocots and dicots. We found that small inversions were much more common than large inversions. The small inversions were scattered over the chloroplast genome including the IR, SSC, and LSC regions. Several small inversions were uncovered in chloroplast genomes even though they shared the same overall gene order. The majority of these small inversions were located within 100 bp downstream of the 3' ends of genes. All had inverted repeat sequences, ranging from 11 to 24 bp, at their ends. Such small inversions form stem-loop hairpin structures that usually have the function of stabilizing the corresponding mRNA molecules. Intra-molecular recombination between the inverted sequences in the stem-forming regions are responsible for generating flip-flop orientations of the loops. The presence of two different orientations of the stem-loop in the trnL-F noncoding region of a single species of Jasminum elegans suggests that a short inversion can be generated within a short period of time. Small inversions of non-coding sequences may influence sequence alignment and character interpretation in phylogeny reconstructions, as shown in nine species of Jasminum. Many small inversions may have been generated by parallel or back mutation events during chloroplast genome evolution. Our data indicate that caution is needed when using chloroplast non-coding sequences for phylogenetic analysis.

소수력 발전시스템 무인화 개발

  • Park, Bong-Il;Park, Wan-Sun;Park, Joon-Sik
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 추계학술대회
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    • pp.511-514
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    • 2006
  • 1. 소수력 발전시스템의 자동화 및 고장진단 알고리즘, 2. 종합 제어시스템의 성능 실험과 원격제어 시스템의 개발, 3. 소수력 발전 시스템의 무인 종합 제어시스템 개발

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Transformation and Gene Expression in Arabidopsis thaliana (Arabidopsis의 형질전환과 유전자 발현)

  • 백경희
    • Proceedings of the Botanical Society of Korea Conference
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    • 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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    • pp.169-174
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    • 1987
  • Arabidopsis thaliana has been used as a good model system for the molercular biological studies on plants for following reasons. It has small gonome size and short generation time, with easiness to obtain mutants and to be transformed. Prospect of its use in applied field is discussed briefly.

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Cause Analysis for the Wall Thinning and Leakage of a Small Bore Piping Downstream of an Orifice (주증기계통 오리피스 후단 소구경 배관의 감육 및 누설 발생)

  • Hwang, Kyeong Mo
    • Corrosion Science and Technology
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    • 제12권5호
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    • pp.227-232
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    • 2013
  • A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one (1) inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1,000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed on in front of the orifice. This paper deals with UT (Ultrasonic Test) thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.