• Title/Summary/Keyword: Photon flux

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Effects of Photosynthetic Photon Flux and Electric Conductivity on the Leaf Temperature of Potato Transplants (감자묘 엽온 변화에 미치는 광합성유효광양자속과 전기전도도의 영향)

  • 이상헌;김용현;최유화;이명규;김진국
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.02a
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    • pp.412-417
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    • 2003
  • 작물의 생장상태를 측정하고자 기존의 연구자들에 의해서 많은 연구가 수행되고 있다. 그러나 작물의 생장을 감시하기 위한 기존의 방법은 파괴적이며 지속적이지 못하다는 단점을 지니고 있다. 작물이 생장 장해를 받아 눈에 띄게 작물의 생장변화가 보일 경우 작물은 이미 영구적인 손상을 받게 진다. 따라서 이런 작물의 생장 장해를 조기에 진단하여 작물의 생장 장해에 능동적으로 반응할 수 있는 방법의 개발이 절실히 요구된다. (중략)

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Quality of Potato Plug Seedlings as Affected by Photosynthetic Photon Flux and Electric Conductivity of Nutrient Solution (광합성유효광양자속과 배양액의 전기전도도가 감자 플러그묘의 묘소질에 미치는 영향)

  • 이상헌;김용현;이명규;최유화
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2003.04a
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    • pp.140-145
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    • 2003
  • 폐쇄형 묘생산 시스템을에서 기내 배양된 감자 소식물체를 이용하여 플러그묘의 생산이 시도(Kim 등, 2002)된 이래 묘소질이 우수한 감자 플러그묘를 생산하기 위한 연구가 지속되고 있다(이 등, 2002, 2003). 묘소질은 정식 후 활착의 용이, 수량 증대 및 품질의 우수성을 제공하는 잠재력으로서, 초장, 절간장, 엽형, 엽색 등과 같은 외적 소질과 광합성속도, 엽록소함량, 근활력 등 내적 소질로 구분된다(Kim, 2002). (중략)

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Growth and Development of Bottle Gourd(Lagenaria siceraria Standl.) for Rootstock Affected by Photosynthetic Photon Flux and Photoperiod (광합성유효광량자속과 광주기에 따른 대목용 박의 생육 특성)

  • 김용현;박현수
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2000.10b
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    • pp.19-22
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    • 2000
  • 접목을 실시할 때 접수와 대목의 적정한 생육은 접목을 용이하게 할 뿐만 아니라 활착 후 접목묘의 묘소질 지속에도 커다란 영향을 미칠 수 있다. 자연광 조건에서 육묘를 실시하면 묘의 생육이 불균일하여 묘소질이 일정치 않게 된다. 그러므로 인공광을 이용한 폐쇄된 환경 조건에서 육묘가 바람직하나, 대목용 박에 대한 적정 광합성 유효광량자속 또는 광주기가 제시되지 않고 있다. 본 연구의 목적은 대목용 박의 초기 생육에 미치는 광합성 유효광량자속과 광주기의 영향을 구명하는 데 있다. (중략)

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Control of Photosynthetic Photon Flux by the Artificial Lighting in Greenhouse (인공광을 이용한 온실의 광합성유효광양자속 조절)

  • 이현우;이석건;이종원;손갑수
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2002.04a
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    • pp.20-24
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    • 2002
  • 농산물은 기후와 시장동향에 따라 물량, 품질, 가격이 변동하고 산지에 따라 상품규격이나 품종이 다양하기 때문에 적기에 수출물량을 공급하고 지속적으로 확보하는 것이 어려운 문제로 대두되고 있다. 따라서 앞으로 농산물의 국제 경쟁력은 상품의 고품질화와 시장의 변화에 따른 상품의 안정적 공급에 달려 있다고 할 것이다. 연구결과에 의하면 작물이 안정적으로 생장하고 고품질의 수확물을 지속적으로 생산하기 위해서는 적정 일일적산 광합성유효광양자속을 균일하게 공급할수 있어야한다. (중략)

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Growth Model of Leaf Lettuce Based on the Cumulative Photosynthetic Photon Flux Density (적산일사량에 따른 상추 생육모델)

  • 문보흠;이병일
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2002.04a
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    • pp.85-92
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    • 2002
  • 채소는 다른 작물에 비해 생육기간이 매우 짧기 때문에 환경의 영향을 많이 받는다. 특히 환경이 제어되는 시설에서 양액재배를 할 경우에는 생육이 왕성하므로 노지에 비해 재배기간을 단축시킬 수 있으며, 근권부 양액제어나 지상부 환경제어를 통해 고품질 채소를 생산할 수 있는 장점이 있다. 따라서 빠른 생육을 제어하거나 예측할 수 없어 수확적기를 놓치면 외관적 품질이 현저히 떨어지고 질적 품질도 저하하여 소비자의 기호에 맞추기 힘들게 된다. (중략)

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Properties of transient horizontal magnetic fields and their implication to the origin of quiet-Sun magnetism

  • Ishikawa, Ryohko
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.84.1-84.1
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    • 2012
  • Recent spectropolarimetric observations with high spatial resolution and high polarization sensitivity have provided us with new insight to better understand the quiet-Sun magnetism. This talk is concerned with the ubiquitous transient horizontal magnetic fields in the quiet-Sun, as revealed by the Solar Optical Telescope (SOT) on board Hinode satellite. Exploiting the SOT data with careful treatment of photon noise, we reveal the enigmatic properties of these horizontal magnetic fields such as lifetime, size, position in terms of granular structure, occurrence rate, three-dimensional structure, total magnetic flux, field strength distribution, relationship with the meso- and super-granulations and so on. Based on these observational consequences, we conjecture that the local dynamo process, which takes place in a relatively shallow layer with the granular size, produces these transient horizontal magnetic fields and that these horizontal magnetic fields contribute to the considerable amount of quiet-Sun magnetic fields. We also estimate the magnetic energy flux carried by these horizontal magnetic fields based on the statistical data, and find that the total magnetic energy is comparable to the total chromospheric and coronal energy loss, implying their important role for the chromospheric heating and dynamism.

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Dust Scattering in Turbulent Media: Correlation between the Scattered Light and Dust Column Density

  • Seon, Kwang-Il;Witt, Adolf N.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.59.2-59.2
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    • 2014
  • Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the scattered light and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the scattered light and optical depth shows substantial scatter and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in scattered light. In other words, there is an enhancement of the dust-scattered flux in low-density regions, while the scattered flux is suppressed in high-density regions. The correlation becomes less significant as the scattering becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the scattered light observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between scattered lights at two different wavelengths shows a tighter correlation than that of the scattered light versus the optical depth.

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Effects of LED Light Quality of Urban Agricultural Plant Factories on the Growth of Daughter Plants of 'Seolhyang' Strawberry

  • Lee, Kook-Han
    • Journal of Environmental Science International
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    • v.27 no.10
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    • pp.821-829
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    • 2018
  • This study was conducted to examine the influence of Light-Emitting Diode (LED) light quality in urban agricultural plant factories on the growth and development of Seolhyang strawberry daughter plants in order to improve the efficiency of daughter plant growth and urban agriculture. LED light quality by demonstrated that above-ground growth and development were greatest for daughter plant 2. Daughter plant 1 showed the next highest growth and development, followed by daughter plant 3. Among the different qualities of LED light, the stem was thickest and growth rate of leaves was highest for R + B III (LED quality: red 660 nm + blue 450 nm/photosynthetic photon flux density (PPFD): $241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R (red $660nm/115-117{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). Plant height, leaf width, petiole length, and the leaf growth rate were highest for W (white fluorescent lamp/$241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R + B I (red 660nm+blue 450nm/$80-82{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). For above-ground growth and development, as the plants surpassed the seedling age, mixed light (red + blue), rather than monochromatic light (red or blue), and higher PPFD values tended to increase development. Regarding the quality of the LED light, daughter plant 2 showed the highest chlorophyll content, followed by daughter plant 1, and daughter plant 3 showed the least chlorophyll content. When the wavelength was monochromatic, chlorophyll content increased, compared to that when PPFD values were increased. Mixed light vitality was highest in daughter plant 2, followed by 1, and 3, showed increased photosynthesis when PPFD values were high with mixed light, in contrast to the results observed for chlorophyll content.

Effects of Light Intensity and Nutrient Level on Growth and Quality of Leaf Lettuce in a Plant Factory (식물공장내 광도와 배양액농도가 상추의 생육과 품질에 미치는 영향)

  • Park, Mi-Hee;Lee, Yong-Beom
    • Journal of Bio-Environment Control
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    • v.8 no.2
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    • pp.108-114
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    • 1999
  • This study was conducted to investigate the optimum environment for leaf lettuce (Lactuca sativa L. var. crispa) in a plant factory to increase mass-production efficiency of quality leaf lettuce. Transpiration rate and $CO_2$ assimilation rate were increased with increasing the photosynthetic photon flux density (PPFD). The highest fresh weight and dry weight were observed at the PPFD of 200 and 300 U moi $m^{-2}$ $s^{-l}$, respectively. The optimum aerial environment for the growth and quality of leaf lettuce in the plant factory was determined to be over 200 $\mu$mol $m^{-2}$ $s^{-1}$ for PPFB. Although the interaction between light intensity and nutrient level was not significant, the lettuce growth was the best under electrical conductivity (EC) of 1.8 mS $cm^{-1}$ / at high light intensity (250 $\mu$mol $m^{-2}$ $s^{-1}$ ) and EC of 2.4 mS cm-1 at low light level (150 $\mu$mol $m^{-2}$ $s^{-1}$ ) respectively.y.

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