• Horticultural Science & Technology
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• v.32 no.4
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• pp.493-498
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• 2014

The objective of this study was to make growth and yield models for common ice plant (Mesembryanthemum crystallinum L.) using expolinear functional equations in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-hours photoperiod were used, and the light intensity was $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Nutrient film systems with three layers were used for plant growth. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Leaf area, shoot fresh and dry weights, light use efficiency of common ice plant as function of days after transplanting, accumulative temperature and accumulative radiation were analyzed. Leaf area, shoot fresh and dry weights per area were described using an expolinear equation. A linear relationship between shoot dry and fresh weights was observed. Light use efficiency of common ice plant was $3.3g{\cdot}MJ^{-1}$ at 30 days after transplanting. It is concluded that the expolinear growth model can be a useful tool for quantifying the growth and yield of common ice plant in a closed plant production system.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.84-93
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• 2016

Plant factories with artificial lights require a large amount of electrical energy for lighting; therefore, enhancement of light use efficiency will decrease the cost of plant production. The objective of this study was to enhance the light use efficiency by using filters to diffuse the light from LED sources in plant factory conditions. The two treatments used diffuse glasses with haze factors of 40% and 80%, and a control without the filter. For each treatment, canopy light distribution was evaluated by a 3-D ray tracing method and canopy photosynthesis was measured with a sealed acrylic chamber. Sixteen lettuces for each treatment were cultivated hydroponically in a plant factory for 28 days after transplanting and their growth was compared. Simulation results showed that the light absorption was concentrated on the upper part of the lettuce canopy in treatments and control. The control showed particularly poor canopy light distribution with hotspots of light intensity; thus the light use efficiency decreased compared to the treatments. Total light absorption was the highest in the control; however, the amount of effective light absorption was higher in treatments than the control, and was highest in treatment using filters with a haze factor of 80%. Canopy photosynthesis and plant growth were significantly higher in all the treatments. In conclusion, application of the diffuse glass filters enhanced the canopy light distribution, photosynthesis, and growth of the plants under LED lighting, resulting in enhanced the light use efficiency in plant factory conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.356-360
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• 2005

Mature embryos were aseptically excised with a scalpel and sliced in fragments measuring 0.5 mm in diameter (sliced mature embryo fragment; 4 ${\~}$ 5 fragments/one embryo). Sliced mature embryo fragments of six wheat cultivars were cultured to develop an efficient method of callus induction and plant regeneration. Callus derived from sliced mature embryo fragments showed a good capacity to embryogenesis and regeneration. Furthermore sliced mature embryo fragments decreased contamination from fungi and bacteria. The high efficiency of callus induction were obtained Keumkangmil and Bob­white. For plant regeneration, selected embryogenic calli were transferred to two types regeneration media. An average number of green spots per callus was 4 to 5 in regeneration media after about one week. Percentage of plant regeneration showed high in regeneration medium containing 0.1 mg/l 2,4-D and 5 mg/l zeatin. Especially, Keumkangmil ($27.5\%$) and Bobwhite ($33.3\%$) showed high regeneration efficiency. This regeneration system from sliced mature embryo fragments may provide an effective and convenient explant for plant transformation studies.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.881-888
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• 2007

In order to investigate the characteristics of the non-biodegradable material, the $BOD_5/COD_{Cr}$ ratio was used. The average ratio of industrial complex's influent wastewater was 2.29~2.96, the effluent ratio was 4.29~19.0. The removal efficiency of $UV_{254}$ by physicochemical treatment was 22.8~94.7% and 5.3~77.2% by biological treatment, respectively. Of the wastewater removal efficiency for each of the items, the $BOD_5$ treatment efficiency was the greatest at 97.3% and the color & TN treatment efficiency was 40~70%. The study of the economical assessment showed that the complex as well as the individual companies spent 722~1,298 won for each ton of treated wastewater. All of the wastewater treatment facilities spent the most money on chemicals needed to treat the wastewater. The total cost for Nylon manufacturing wastewater treatment plant was the greatest while the total cost for cotton manufacturing wastewater treatment plant turned out to the lowest. As respects of removal efficiency and economocal assessment, Polyester A and Cotton manufacturing wastewater treatment plants were better effective than a dyeing industrial complex wastewater treatment plant.

• Molecules and Cells
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• v.37 no.8
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• pp.575-584
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• 2014

Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.52-52
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• 2018

Development of herbicide resistant transgenic legume plants through Agrobacterium-mediated transformation has been worked in many previous studied. Plant regeneration after infection is the important step to obtain successful transgenic plants. Many attempts try to find the optimum media condition for plant regeneration after infection. However, the transformation efficiency of legume plants is still low. In this study, regeneration of some Korean legume species including two soybean cultivars (Dawon and Pungsan) and pea have been done with organogenesis which is used various kind of explants such as cotyledonary-nodes in soybean and bud-containing tissue in pea. We developed the optimum media condition for plant regeneration regulators under Agrobacterium-mediated transformation using different kind and various concentration of plant growth. As the results, B5 medium containing 2 mg/L of 6-benzylaminopurine was selected in this study for the optimum plant regeneration media. The segments were inoculated with Agrobacterium suspension harbored an IG2 vector containing bar gene which confers resistance to phosphinotricin (PPT) in 3, 5 and 7 days. The transformation efficiency was achieved in Dawon 3.03 % and pea 1.46 % with co-cultivation period of 7 days which is showed a high number of GUS positive expression period.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.517-520
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• 2006

The Korean peninsula has a number of coastal sites where the rhythmic rising and lowering of water surface due to tides results in strong tidal current. The kinetic energy of these currents can be efficiently exploited by use of tidal current turbines. The pilot tidal current power plant is to be constructed at the Uldolmok narrow channel between J info and Haenam, Our ins next Year, and extensive coastal engineer ing research works have been carried out. This paper describes and analyzes some observation results of field test about the efficiency of Helical turbine for tidal current power plant. The efficiency of turbine, which is diameter 2.2m and height 2.5m, is evaluated meximum RPM, torque, and current velocity. The tested turbines had the maximum efficiencies of the bounds of 25 to 35% in the current velocity range between 1.4 and 2.6 m/s. This result shows that the pilot tidal current power plant needs three helical turbines with diameter 3.0m and height 3.6m to produce electric power 500kW.

• New & Renewable Energy
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• v.4 no.2
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• pp.31-38
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• 2008

Using a surplus head in presented water supply pipes, we have studied to improve the operating efficiency of small hydro generator, which was chosen for a test model with 00 hydro power plant. With regard to power control and countermeasure of water hammer impact, Finally we have represented the optimal control method through the synthetical analysis of existing system symptoms, operation efficiency, the effect of water hammer impact and system configuration.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1676-1681
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• 2004

The main reason for applying positive pressure variable clearance packing in fossil power plant is high efficiency and energy saving movement in the government. This study intends to analyze the turbine efficiency through the shaft packing improvement in thermal power plant and makes its comparison to that of the each packing type

• The Plant Pathology Journal
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• v.35 no.5
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• pp.521-529
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• 2019

Tomato yellow leaf curl China virus is a species of the widespread geminiviruses. The infection of Nicotiana benthamiana by Tomato yellow leaf curl China virus (TYLCCNV) causes a reduction in photosynthetic activity, which is part of the viral symptoms. ${\beta}C1$ is a viral factor encoded by the betasatellite DNA ($DNA{\beta}$) accompanying TYLCCNV. It is a major viral pathogenicity factor of TYLCCNV. To elucidate the effect of ${\beta}C1$ on plants' photosynthesis, we measured the relative chlorophyll (Chl) content and Chl fluorescence in TY-LCCNV-infected and ${\beta}C1$ transgenic N. benthamiana plants. The results showed that Chl content is reduced in TYLCCNV A-infected, TYLCCNV A plus $DNA{\beta}$ (TYLCCNV A + ${\beta}$)-infected and ${\beta}C1$ transgenic plants. Further, changes in Chl fluorescence parameters, such as electron transport rate, $F_v/F_m$, NPQ, and qP, revealed that photosynthetic efficiency is compromised in the aforementioned N. benthamiana plants. The presense of ${\beta}C1$ aggravated the decrease of Chl content and photosynthetic efficiency during viral infection. Additionally, the real-time quantitative PCR analysis of oxygen evolving complex genes in photosystem II, such as PsbO, PsbP, PsbQ, and PsbR, showed a significant reduction of the relative expression of these genes at the late stage of TYLCCNV A + ${\beta}$ infection and at the vegetative stage of ${\beta}C1$ transgenic N. benthamiana plants. In summary, this study revealed the pathogenicity of TYLCCNV in photosynthesis and disclosed the effect of ${\beta}C1$ in exacerbating the damage in photosynthesis efficiency by TYLCCNV infection.