• 제목/요약/키워드: GROWTH RESEARCH

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고려인삼의 조직배양에 의한 사포닌 생산 (Saponin Production in Tissue Culture of Ginseng (Panax ginseng C.A. Meyer))

  • Choi, Kwang-Tae;Park, Ji-Chang;Ahn, In-Ok
    • Journal of Ginseng Research
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    • 제14권2호
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    • pp.107-111
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    • 1990
  • Ginseng root explants and calli were cultured on modified Murashine and Skoog's media supplemented with different concentrations of organic or inorganic compounds and plant growth requlators to clarify the effects of chemical compositon and plant growth regulators in the medium on the growth of ginseng calli and the production of ginseng saponin. For optimum growth of ginseng calli, the concentrations of 2, 4-D and sucrose were in the range of 1 to 5 mg/l and 1 to 3%, respectively. And it was clarified that sucrose, nitrogen, phosphate, calcium, magnesium, plant growth regulators and their concentrations influcenced the relative biosynthesis of saponin in tissue cultures of Panax ginseng.

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기술혁신과 경제성장 연구의 현황과 과제: 한국에 대한 논의를 중심으로 (The Current Research Trends and Challenges on Technological Innovation and Economic Growth: A Focus of Korean Cases)

  • 정준호
    • 기술혁신연구
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    • 제25권4호
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    • pp.47-77
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    • 2017
  • 본고는 기술혁신과 경제성장 간의 관계에 대한 연구동향을 비판적으로 검토한다. 경제성장에서 혁신의 역할에 대한 여러 가지 입장들이 존재하며 이러한 입장들에 따라 그러한 연구동향을 정리한다. 신고전파의 성장론, 국가혁신체제론, 기술역량론, 경제추격론 등의 관점에 따라 한국을 대상으로 한 기술혁신과 경제성장에 관한 국내 외 연구가 본고의 검토대상이다. 이러한 비판적 검토와 성찰을 통해 앞으로의 연구과제들을 제시한다.

고온 기기의 크리프-피로 균열성장 평가 (Assessment of Creep-Fatigue Crack Growth for a High Temperature Component)

  • 이형연;김종범;이재한
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.264-268
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    • 2008
  • An assessment of creep-fatigue crack behavior is required to ensure the structural integrity for high temperature components such as fast breeder reactor structures or thermal power plant components operating at an elevated temperature. In this study, an evaluation of creep-fatigue crack growth has been carried out according to the French assessment guide of the RCC-MR A16 for austenitic stainless steel structures. The assessment procedures for creep-fatigue crack growth in the recent version of the A16 (2007 edition) have been changed considerably from the previous version (2002 edition) and the material properties (RCC-MR Appendix A3) have been changed as well. The impacts of those changes on creep-fatigue crack growth behavior are quantified from the assessments with a structural model. Finally the assessment results were compared with the observed images obtained from the structural tests of the same structural specimen.

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Effects of seed geometry on the crystal growth and the magnetic properties of single grain REBCO bulk superconductors

  • Lee, Hwi-Joo;Park, Soon-dong;Jun, Bung-Hyuck;Kim, Chan-Joong;Lee, Hee-Gyoun
    • 한국초전도ㆍ저온공학회논문지
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    • 제19권3호
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    • pp.33-39
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    • 2017
  • This study presents that the orientation and the geometry of seed affect on the growth behavior of melt processed single grain REBCO bulk superconductor and its magnetic properties. The effects of seed geometry have been investigated for thin $30mm{\times}30mm$ rectangular powder compacts. Single grain REBCO bulk superconductors have been grown successfully by a top seed melt growth method for 8-mm thick vertical thin REBCO slab. Asymmetric structures have been developed at the front surface and at the rear surface of the specimen. Higher magnetic properties have been obtained for the specimen that c-axis is normal to the specimen surface. The relationships between microstructure, grain growth and magnetic properties have been discussed.

Optimal Conditions for the Mycelial Growth of Coprinus comatus Strains

  • Jang, Myoung-Jun;Lee, Yun-Hae;Liu, Jun-Jie;Ju, Young-Cheol
    • Mycobiology
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    • 제37권2호
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    • pp.103-108
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    • 2009
  • The principal objective of this study was to acquire basic data regarding the mycelial growth characteristics for the artificial cultivation of Coprinus comatus. 12 URP primers were employed to evaluate the genetic relationships of C. comatus, and the results were divided into three groups. Among six kinds of mushroom media, MYP medium was selected as the most favorable culture medium for C. comatus. The optimal temperature and pH ranges for the mycelial growth of C. comatus were $23{\sim}26^{\circ}C$ and pH 6${\sim}$8, respectively. The carbon and nitrogen sources for optimal mycelial growth were sucrose and tryptone, respectively.

Effect of Residual Binder on Grain Growth during Sintering of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$

  • Yun, Jung-Yeul;Jang, Wook-Kyung;Jeon, Jae-Ho;L.Kang, Suk-Joong
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.209-210
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    • 2006
  • Organic binders are usually pre-mixed with ceramic powders to enhance the formability during the shape forming process. These binders, however, must be eliminated before sintering in order to avoid pore formation and unusual grain growth during sintering. The present work was performed to investigate the effects of residual binder on grain growth behavior during sintering of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ piezoelectric ceramics. The microstructures of sintered samples were examined for various thermal processes and atmosphere at debinding. Addition of binder seems to promote abnormal grain growth especially in incompletely debinded regions and to make the grain shape change from corner-rounded to faceted.

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PRODUCTION OF GINSENOSIDES THROUGH IN VITRO CULTURE OF GINSENG(Panax ginseng C.A. MEYER)

  • Choi K.T.;Ahn I.O.;Park J.C.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1993년도 학술대회지
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    • pp.143-149
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    • 1993
  • Ginseng root explants and calli induced from selected cell lines were cultured on modified Murashige and Skoog's media supplemented with different concentrations of organic or inorganic compounds and plant growth requlators to clarify the effects of chemical composition and plant growth regulators in the medium on the growth of ginseng calli and the production of ginseng saponin. For optimum growth of calli, the concentrations of 2, 4-D and sucrose were the range of 1 to 3 mg/${\ell}$l and 1 to $3\%,$ respectively. And it was clarified that sucrose, nitrogen, phosphate, calcium, magmesian plant growth regulators and their concentrations influcenced the relative biosynthesis of saponin in tissue cultures of Panax ginseng. The patterns of ginsenosides, pharmacologically useful component, were different among the cell lines and contents of ginsenosides were much higher in selected cell lines than in original cell line.

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Relationship Between Heat Unit Requirement and Growth and Yield of Mulberry, Morns indica L.

  • Sarkar A.;Rekha M.;Keshavacharyulu K.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제10권1호
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    • pp.65-68
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    • 2005
  • Growth and development of a plant over a growing season is closely related to the daily accumulation of heat. Heat unit measured by accumulated growing degree days (GDD) is becoming increasingly popular to estimate the growth of a plant or even in insect. GDD or heat accumulation per day is measured by calculating average daily temperature and then subtracting the base temperature below which growth does not occur. Heat accumulation per day is added for the desired period and accumulated GDD is determined. The present study was conducted in five seasons in an established garden with K-2, S-36 and V-1 mulberry varieties belonging to Morus indica L. grown under completely irrigated condition at the farm of CSRTI, Mysore during 2001 - 2002. Plants were pruned in each season and the growth of the plant measured by total shoot length and fresh leaf yield was recorded at an interval of 5 days starting from 30 days of pruning (DAP) to 70 days when all the plants were pruned. The accumulated GDD for the corresponding days were recorded and used for analysis. Accumulated growing degree days (GDD) have been found to be perfectly correlated with both growth and yield in all the seasons in all the varieties studied. The high $R^2$ values indicated a strong relationship between the accumulated GDD and, growth and yield of mulberry.

Fatigue Crack Growth Characteristics of the Pressure Vessel Steel SA 508 Cl. 3 in Various Environments

  • Lee, S. G.;Kim, I. S.;Park, Y. S.;Kim, J. W.;Park, C. Y.
    • Nuclear Engineering and Technology
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    • 제33권5호
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    • pp.526-538
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    • 2001
  • Fatigue tests in air and in room temperature water were performed to obtain comparable data and stable crack measuring conditions. In air environment, fatigue crack growth rate was increased with increasing temperature due to an increase in crack tip oxidation rate. In room temperature water, the fatigue crack growth rate was faster than in air and crack path varied on loading conditions. In simulated light water reactor (LWR) conditions, there was little environmental effect on the fatigue crack growth rate (FCGR) at low dissolved oxygen or at high loading frequency conditions. While the FCGR was enhanced at high oxygen condition, and the enhancement of crack growth rate increased as loading frequency decreased to a critical value. In fractography, environmentally assisted cracks, such as semi-cleavage and secondary intergranular crack, were found near sulfide inclusions only at high dissolved oxygen and low loading frequency condition. The high crack growth rate was related to environmentally assisted crack. These results indicated that environmentally assisted crack could be formed by the Electrochemical effect in specific loading condition.

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A Study on the Growth Characteristics of Multi-layer Planted Trees through Growth Analysis - With a Focus on Seoul Forest Park -

  • Kim, Han Soo;Ban, Soo Hong
    • 한국환경생태학회지
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    • 제29권2호
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    • pp.279-291
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    • 2015
  • This study analyzed the growth characteristics of multi-layer planted trees through their growth analysis and attempted to present a management strategy. The subject of research is the Citizen's Forest Area of Seoul Forest Park located in Seoul City. Field surveys were conducted three times over eight years from 2005 when the Seoul Forest Park was created through 2013. Labels were attached to all trees in the target area, and their species, height and DBH were investigated. To identify the growth differences by trees in each area, a detailed tree location map was drawn up for use in the analysis. To check soil health, soil organic matter, soil pH and soil microbial activities were analyzed. It turned out that the growth of the multi-layer planted trees in the target area of research was higher than that of the trees in existing urban parks, and that it was similar to that of trees in natural forests. Through a field survey in the area with a remarkably low growth, high-density planting problem, soil was found to have excess-moisture and there was the problem of Pueraria lobata covering. As a result of the analysis of the soil, it was found that its organic content in the soil was lower; soil pH was higher; and microbial activities in the soil were lower when compared to that of natural forests.