• Analytical Science and Technology
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• v.22 no.4
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• pp.277-284
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• 2009

The germination rate of radishes grown with the far infrared irradiated water and drinking water was 100% and 78% respectively. The far infrared irradiated water stimulated the cell division of the cotyledons and enlarged the cell sizes both in the dark and in the light. In the dark and light conditions, the size of the cotyledons of transversal axis and longitudinal axis grown with the far infrared irradiated water was bigger than that grown with the drinking water. The content of chlorophyll and the consumption of $CO_2$ of the cotyledons grown with the far infrared irradiated water were higher, respectively. Osmotic pressure of the cotyledons grown with the far infrared irradiated water was 1.25 factors higher than that grown with the drinking water. The water potential of the cotyledons grown with the far infrared irradiated water was more negative value. The length of hypocotyls grown with the far infrared irradiated water was 2.18 factors longer in the dark, 1.99 factors longer in the light than that grown with the drinking water and the radish roots grown with the far infrared irradiated water were larger, respectively.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.71-77
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• 2014

In this paper, we investigated the effects of high-energy electron beam irradiation (HEEBI) on the optical transmittance of InGaZnO (IGZO) films grown on transparent Corning glass substrates, with a radio frequency magnetron sputtering technique. The IGZO thin films deposited at low temperature were treated with HEEBI in air at room temperature (RT) with an electron beam energy of 0.8 MeV and doses of $1{\times}10^{14}-1{\times}10^{16}electrons/cm^2$. The optical transmittance of the IGZO films was measured using an ultraviolet visible near-infrared spectrophotometer (UVVIS). The detailed estimation process for separating the transmittance of HEEBI-treated IGZO films from the total transmittance of IGZO films on transparent substrates treated with HEEBI is given in this paper. Based on the experimental results, we concluded that HEEBI with an appropriate dose of $10^{14}electrons/cm^2$ causes a maximum increase in the transparency of IGZO thin films. We also concluded that HEEBI treatment with an appropriate dose shifted the optical band gap ($E_g$) toward the lower energy region from 3.38 to 3.31 eV. This $E_g$ shift suggested that HEEBI in air at RT with an appropriate dose acts like a thermal annealing treatment in vacuum at high temperature.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.224-228
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• 2012

BACKGROUND: This experiment was conducted to investigate the effects of red light on inhibition of flowering and vegetative growth of perilla (Perilla Frutescens. L). METHODS AND RESULTS: To determine red light intensity for inhibiting floral induction of perilla 6h light plus daylength extension (17:00-23:00) with three different intensity of red lights 0.046, 0.114 and $0.177{\mu}mol/m^2/s$ were treated respectively, and control plants were grown under 11(06:00-17:00)/13(17:00-06:00)h light/dark environment. Red(660nm) and far-red(730nm) light were irradiated for night break treatment subsequently to investigate photoreversible flowering response of perilla 'Manchu'. The flowering was inhibited by night break with red light, but sequential far-red light induced floral induction of perilla. Perilla not flowered by red light intensity over $0.177{\mu}mol/m^2/s$. Red light of $0.2{\mu}mol/m^2/s$ was irradiated for 6 hours (20:00-02:00) with LEDs device in plastic house. Perilla not flowered and continued the vegetative growth by red light treatment and the plant length, number of leaves, fresh weight, and leaf area of perilla were increased by 3%, 7%, 21%, and 19%, respectively, compared to incandescent control. CONCLUSION: These results showed that red(660nm) light for daylength extension could be used to control flowering and to enhance production of perilla leaf.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.180-185
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• 2012

The objective of this study was carried out to elucidate the effect of LEDs (light emitting diodes) irradiation in relation to early growth and inorganic elements in leaf lettuce (Lactuca sativa L. 'Rollo Rosa'). In morphological changes of leaves, shoot elongation and hypocotyl length showed poor growth in red light irradiation, while the red + blue light irradiation induced shorter plant height and much greater leaf numbers resulting in increased fresh weight. In change of the Hunter's color and SPAD values, lettuce seedlings grown under in red + blue and fluorescent light irradiation had a higher $a^*$ value, otherwise SPAD values were not changed in these light irradiations. Interestingly, relative chlorophyll contents showed 1.8 times increased redness in the treatment of red + blue light irradiation. Inorganic element (N, Ca, Mg, Mn, and Fe) and ascorbic acid contents were increased in lettuce plants grown under LEDs light irradiation compared to those of lettuce grown under the fluorescent light which showed higher P and Mn contents. In conclusion, it is considered that red + blue light irradiation which stimulates growth and higher nutrient uptake in leaf lettuce could be employed in containers equipped with LEDs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.1-11
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• 2007

Light is an environmental component inevitably regulating photosynthesis and photo-morphogenesis, which are involved in the plant growth and development. Studies were conducted at the International Rice Research Institute, Philippines in 2004 and 2005, with aims to investigate 1) morphological responses of rice plants to low radiation, 2) morphological alteration of shade-grown plants when exposed to high light intensity, and 3) photosynthetic responses of shade-grown rice plants. Reduction in solar radiation by 40% induced increases in the area on a single leaf basis, biomass partitioning to leaves, and chlorophyll meter readings but brought about retardation of tiller development and decrease in above-ground biomass production of rice varieties. When the shade-grown plants from two weeks of transplanting to panicle initiation were exposed to full solar radiation after panicle initiation, they demonstrated less increase in chlorophyll meter readings and more decrease in leaf nitrogen concentrations from panicle initiation to flowering than control plants that were grown under the ambient solar radiation for whole growth period after transplanting. Shade-grown rice plants exhibited lower carbon assimilation rates but higher internal $CO_2$ concentrations on a single leaf basis than control plants, when measurements for shade-grown rice plants were made under the shading treatments. But when the measurements for shade-grown plants were made under the full solar radiation, light-saturated carbon assimilation rates were similar to control plants. Response of photosynthetic rates to varying light intensities was not considerably different between shading treatments and control. Yield reduction was observed in the shading treatments from panicle initiation to flowering and from flowering to physiological maturity, mainly by less spikelets per panicle and poor grain filling, respectively.

• Korean Journal of Weed Science
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• v.8 no.1
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• pp.15-22
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• 1988

In this experiment, interactions between light and other factors such as chilling, alternating temperature, moisture, content, oxygen, and seed coat which affect germination of Oenothera lamarckiana Ser. seed were investigated to study the physiological effects of light on the germination. Light induced the initial stage of seed germination before radical protrusion by affecting embryo rather than seed coat even under anaerobic condition or low water potential (-18 bars). This light effect on germinability of seed was suppressed by blue light irradiation and the effect was increased with increment of blue light intensity and irradiation time. However, the blue light effect was reversible. Chilling, alternating temperature, softening of seed coat and light showed promotive interaction in the induction of seed germination. Irradiation of filtered light (monochrome), however, reduced chilling effect on germination. Hydrogen-ion concentration and gibberellic acid treatment had no effect on light or dark germination.

• Journal of Bio-Environment Control
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• v.19 no.2
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• pp.97-108
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• 2010

The present study was conducted to investigate photosynthetic responses (Pn), chlorophyll fluorescence (Pe), chlorophyll contents of Allium victorialis var. platyphyllum, Ligularia fischeri, and Ligularia stenocephala growing at four different fertilizing schemes (non-fertilizing and 2.5 $g{\cdot}l^{-1}$, 5 $g{\cdot}l^{-1}$, 10 $g{\cdot}l^{-1}$ fertilizing). Three wild vegetables showed outstanding Pn and Pe at 5 $g{\cdot}l^{-1}$ fertilizing treatment. 10 $g{\cdot}l^{-1}$ of fertilizer, however, proved to be too much eventually leading to declined growth. A. victorialis var. platyphyllum showed good Pn and Pe under shade treatment whereas Pn and Pe of L. fischeri, and L. stenocephala showed the opposite tendency. The chlorophyll contents of the three wild vegetables showed the highest measurement ranging between 11.70~24.36 $mg{\cdot}g^{-1}$ when treated with 5 $g{\cdot}l^{-1}$ of fertilizer. Also it was showed that there were more chlorophyll contents under shade treatment as opposed to full sun. These results showed that 5 $g{\cdot}l^{-1}$ fertilizing treatment is optimal fertilizing of three wild vegetables and fertilizing and light intensity controlling is very important for productivity of vegetables.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.284-293
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• 2000

For the artificial removal of air pollutants such as pesticides, environmental toxicants, and pathogenic microorganisms in the greenhouse or the living environment, the accelerated photodegradation and the biocidal effects of some photosensitizers (PS)/photocatalysts (PC) were tested under the sunlight and/or artificial light. The selected photosensitizers/photocatalysts included the semiconductors (PC-1 and PC-2), the oxidizers (PC-3, PC-4, PC-5 and PC-6), the aromatic ketone (PS-7) and the aromatic amine (PS-8). In the case of dichlorvos, all the photocatalysts selected showed more accelerated photodegradation than the control without photocatalysts under both the sunlight and artificial light. Whereas, only the photocatalyst PC-1 accelerated the degradation of methyl tert-butyl ether about 17 times more than the control under both the sunlight and artificial light. Procymidone was much more degraded by the photosensitizer PS-8 and the two photocatalysts (PC-1, PC-6) than by PS-7. In the preliminary experiments to diminish the population of the microorganisms in the air, the photocatalyst PC-1 added to the suspensions of Pseudomonas putida, Phytophthora capsici, and Salmonella typhimurium obviously inhibited the microbial growth under the artificial light. The photocatalyst PC-1 showed a bactericidal activity against Salmonella typhimurium spread on the nutrient broth agar medium. These results suggest that the photosensitizers/photocatalysis under the light can remove some air pollutants and hence they can be used to reduce the exposure of the workers in the horticultural facilities and/or the public in the environment to the harmful pollutants.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.102-108
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• 2020

This study is to analyze the growth response of the Quercus dentata seedlings to four environmental factors and measure the ecological niche breadth. Environmental factors were light, moisture content, soil texture, and organic matter, treated with four gradients. The more quantity light increased, the heavier the leaves biomass, aboveground biomass, belowground biomass and plant biomass was. In treatment of water content and soil texture, growth response was no difference. The more organic matter increased, the heavier aboveground biomass was, but the remaining trait of plant was no difference. The ecological niche breadth was 0.865 in light, 0.995 in moisture content, 0.994 in soil texture and 0.988 in nutrient. Ecological niche breadth was the widest in the moisture content treatment and the narrowest in the light treatment. This means that the growth of Q. dentata seedlings grows well as the amount of light increases, and is sensitive to light, Thus, it is determined a growth and ecological niche breadth by light factors.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.12-18
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• 1987

Seed dormancy and germination responses to light and gases were determined for Echinochloa colona (L.) Link. E. colons seeds did not require a period of after-ripening for breaking dormancy. Water movement occurred readily across the seed coat. Repeated cycles of hydration and dehydration reduced viability and thence germination. Water imbibition for 24 h increased seed moisture by 21%; seeds returned to their original weight after drying at room temperature for 13 h. Removal of seed-coats increased germination in the dark. Light stimulated germination. Germination at a daylight intensity of 51.9 $Wm^{-2}$ or less was significantly reduced. Germination of seeds which were exposed to light for 1 h each day was significantly less than that of seeds exposed for longer than 2 h a day. Seeds subjected to blue light had delayed and decreased germination compared to seeds exposed to red light. Ethylene or carbon dioxide exogenenously added in the presence of light stimulated germination. The addition of the two gases together had a synergistic effect. In the dark, however, the two gases did not increase germination.