• Title, Summary, Keyword: mass propagation

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Development of Forecast Algorithm for Coronal Mass Ejection Speed and Arrival Time Based on Propagation Tracking by Interplanetary Scintillation g-Value

  • Park, Sa-Rah;Jeon, Ho-Cheol;Kim, Rok-soon;Kim, Jong-Hyeon;Kim, Seung-Jin;Cho, Junghee;Jang, Soojeong
    • Journal of Astronomy and Space Sciences
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    • v.37 no.1
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    • pp.43-50
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    • 2020
  • We have developed an algorithm for tracking coronal mass ejection (CME) propagation that allows us to estimate CME speed and its arrival time at Earth. The algorithm may be used either to forecast the CME's arrival on the day of the forecast or to update the CME tracking information for the next day's forecast. In our case study, we successfully tracked CME propagation using the algorithm based on g-values of interplanetary scintillation (IPS) observation provided by the Institute for Space-Earth Environmental Research (ISEE). We were able to forecast the arrival time (Δt = 0.30 h) and speed (Δv = 20 km/s) of a CME event on October 2, 2000. From the CME-interplanetary CME (ICME) pairs provided by Cane & Richardson (2003), we selected 50 events to evaluate the algorithm's forecast capability. Average errors for arrival time and speed were 11.14 h and 310 km/s, respectively. Results demonstrated that g-values obtained continuously from any single station observation were able to be used as a proxy for CME speed. Therefore, our algorithm may give stable daily forecasts of CME position and speed during propagation in the region of 0.2-1 AU using the IPS g-values, even if IPS velocity observations are insufficient. We expect that this algorithm may be widely accepted for use in space weather forecasting in the near future.

In Vitro Propagation of Medicinal Herbs in Korea

  • An, Chanhoon;Song, Jeongho
    • Journal of Forest and Environmental Science
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    • v.34 no.1
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    • pp.77-81
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    • 2018
  • Mass production of forest medicinal plants is related to quality control of raw medicinal materials. Plant tissue culture is an important technology to produce high-quality plant materials. Numerous factors are reported to influence the success of in vitro regeneration of medicinal plants. Embryogenesis is known to be the most effective techniques and it has developed in some medicinal plant species. Various in vitro cultural condition for direct and/or indirect somatic embryogenesis systems have developed in Epimedium koreaum, Bupleurum falcatum, Paeonia lactiflora, Chrysanthemum zawadskii, Houttuynia cordata etc. In this study, we provide the present statue and information of in vitro propagation techniques that is able to apply as an efficient system for rootstock propagation system of forest medicinal plants.

A Study of the Propagation of Turbulent Premixed Flame Using the Flame Surface Density Model in a Constant Volume Combustion Chamber

  • Lee, Sangsu;Kyungwon Yun;Nakwon Sung
    • Journal of Mechanical Science and Technology
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    • v.16 no.4
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    • pp.564-571
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    • 2002
  • Three-dimensional numerical analysis of the turbulent premixed flame propagation in a constant volume combustion chamber is performed using the KIVA-3V code (Amsden et. al. 1997) by the flame surface density (FSD) model. A simple near-wall boundary condition is eaployed to describe the interaction between turbulent premixed flame and the wall. A mean stretch factor is introduced to include the stretch and curvature effects of turbulence. The results from the FSD model are compared with the experimental results of schlieren photos and pressure measurements. It is found that the burned mass rate and flame propagation by the FSD model are in reasonable agreement with the experimental results. The FSD combustion model proved to be effective for description of turbulent premixed flames.

Micro-propagation Factors Essential for Mass Production of Synthetic Seeds in Banana

  • Hassanein A. M.;Ibrahiem I. A.;Galal A. A.;Salem J. M. M.
    • Journal of Plant Biotechnology
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    • v.7 no.3
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    • pp.175-181
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    • 2005
  • This work described some essential factors necessary for micro-propagation of banana for mass production of synthetic seeds for germ plasm conservation, and how peroxides activity of conserved tissue was influenced. Shoot tips of field grown plants were used to obtain shoot clusters on shoot proliferation medium (MS medium supplemented with 5 mg/l BAP). Using longitudinally-split shoot tip technique, 18720, 8640, 7488, 2016 plantlets were obtained from one shoot tip of Maghraby, Grand Naine, Balady, and Williams, respectively, in six subculture, one month each, on solid medium. Shoot tips excised from in vitro grown plantlets were encapsulated in calcium-alginate beads and stored at $4^{\circ}C$ for one month on half-strength MS basal medium without growth regulators or sugars. After one month all the viable-conserved synseeds formed shoots when they were transferred to MS basal medium, some of them showed synchronous formation of shoot and root systems in one week. Plants retrieved from encapsulated shoot tips were hardened off and transferred to soil.

Effect of Rock Mass Properties on the Blast Vibration by Taguchi method (다꾸치법에 의한 암반물성의 발파진동 영향요소 분석)

  • 김남수;김보현;양형식
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • pp.229-234
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    • 2000
  • The propagation of blast vibration and the damping characteristics depend on both the mechanical properties of rock mass and weight charge. In this study, the characteristics of propagation and damping were analyzed by FLAC. The construction site was the second Kwang-ju circulating read. Taguchi method which is one of experimental design methods was used for determination of input data and parameter levels. The results showed that rock density was the most dominant of variables being concerned in this study, which affect the propagation of blast vibration.

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Effect of Rock Mass Properties on the Blast Vibration by Taguchi method (다꾸치법에 의한 암반물성의 발파진동 영향요소 분석)

  • 김남수;김보현;양형식
    • Tunnel and Underground Space
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    • v.10 no.3
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    • pp.475-480
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    • 2000
  • The propagation of blast vibration and the damping characteristics depend on both the mechanical properties of rock mass and weight charge. In this study, the characteristics of propagation and damping were analyzed by FLAC. The construction site was the second Kwang-ju circulating road. Taguchi method which is one of experimental design methods was used for determination of input data and parameter levels. The results showed that rock density was the most dominant of variables being concerned in this study, which affect the propagation of blast vibration.

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In-cylinder Flame Visualization and Flame Propagation Characteristics of SI Engine by using Optimal Threshold Method (Optimal Threshold 법을 이용한 가솔린 기관의 실린더 내화염 가시화 및 화염 전파 특성에 관한 연구)

  • 김진수;전문수;윤정의
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.96-104
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    • 2000
  • It is well known that combustion stability under idle and part-load conditions directly affect fuel economy and exhaust emission. In practice, there have been a lot of studies so that a significant improvement in combustion stability has been achieved in this research field. However, applying published results to the development process of mass production engine, there are still many problems which are solved previously. In this study, initial flame behavior and flame propagation characteristic were investigated statistically in order to optimize combustion chamber shapes in the development stage of mass production S.I. engine. To the purpose, the authors applied the flame image capturing system to single cylinder optical engine. The captured flame images were effectively analyzed by using the image processing program which was developed by the authors and adopted new threshold algorithm instead of conventional histogram analysis. In addition, the cylinder pressure was also measured simultaneously to compare evaluated flame results with cylinder pressure data in terms of the combustion characteristics, combustion stability, and cycle-to-cycle combustion variability.

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Numerical Analysis for Wave Propagation with Vegetated Coastal Area (연안해역에서의 수변식생에 의한 파란변형에 관한 수치해석)

  • LEE SEONG-DAE
    • Journal of Ocean Engineering and Technology
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    • v.20 no.1
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    • pp.63-68
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    • 2006
  • Recently, it has been widely recognized that coastal vegetations may have great value in supporting fisheries, protecting from wave attack, stabilizing the sea bed and maintaining good scenery. Hydrodynamic factors play a major role in the functions of water quality and ecosystems. However, the studies on physical and numerical process of wave propagation are few and far behind compared to those on the hydrodynamic roles of coastal vegetations. In general, Vegetation flourishing along the coastal areas attenuates the incident waves, through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation rate in the complex topography with the vegetation area. Based on the numerical results, the physical properties of the wave attenuation are examined under various wave, geometric and vegetation conditions. Through the comparisons of these results, the effects of the vegetation properties, wave properties and model parameters such ac the momentum exchange coefficient have been clarified.

탄성정수 및 입사파형의 변화에 따른 암반 내 균열전파양상에 관한 수치해석적 연구

  • Park, Seung-Hwan;Jo, Sang-Ho
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.155-159
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    • 2009
  • Crack-controlled method which utilizes the dynamic energy such as explosives and propellent gases have been applied to the development of mineral resource and oil and civil engineering. It is necessary to consider the fracture processes associated with the material properties and external forces to control crack propagation using borehole pressure. To investigate the influence of the applied borehole pressure waveform on the crack propagation in rock masses having different material properties, a no-free surface model was used, consisting of a borehole in rock with a continuous boundary. Loading rates ranging from 1 to 100MPa/${\mu}s$ with different rock mass properties was employed to investigate the loading rate dependency of fracture patterns in the rock mass.

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Mass Propagation of Sundew, Drosera rotundifolia L. through Shoot Culture

  • Jang, Gi-Won;Park, Ro-Dong
    • Journal of Plant Biotechnology
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    • v.1 no.2
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    • pp.97-100
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    • 1999
  • In order to establish in vitro propagation method of sundew, Drosera rotundifolia L., the effects of MS medium concentration, cytokinin type and concentration, pH, and auxin type and concentration on shoot proliferation and root formation were investigated using shoots at 3 month after seed germination. The highest shoot production was obtained with the half strength of MS ($\frac{1}{2}$ MS) medium than with any other strength of MS medium tested. Addition of kinetin or BA in $\frac{1}{2}$ MS medium was strongly suppressed shoot proliferation. The suppression of shoot proliferation was more effective in BA-supplemented $\frac{1}{2}$ MS medium than kinetin-supplemented. The optimum pH of the media for shoot proliferation was pH 5.7-6.7. Shoots were subcultured in $\frac{1}{2}$ MS medium supplemented with 0.5mg/L 2,4-D for rooting every 8 weeks. All subcultured shoots produced extensive root systems after 5 to 6 week culture. Plantlets after root development were planted in plastic pots filled with moss. The survival rate of plantlets was almost 100%. On subculturing every 8 weeks, hundreds of the plants were propagated from a single plant within a year.

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