• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.677-686
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• 2016

A thermal power plant is the first CFBC (Circulating Fluidized Bed Combustion) power plant consisting of 2 boilers-1 turbine. The optimal height of a stack needs to be approximately 156 meters in the case of this thermal power plant; however, the thermal power plant sites satisfy a function and reduce the construction cost by using mountains in the sites after cutting the ground and locating an integrated office and chimney at an altitude of 70 meters thereby lowering the height of the stack to 86 meters. In addition, the integrated office, which has a combined stack style with a unique design, is constructed by connecting with 2 stacks and disposing the office and an observatory in the space between them. Therefore, this study examined the design concept that fulfils the structural, functional, and aesthetic factors, harmoniously by joining the integrated office and the stack, which are disparate, and investigated special construction methods (Slip Form, Steel Inner Flue & Lift-up) through which heterogeneous architectures are structurally, functionally, and aesthetically constructed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.37-37
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• 2018

We use two different methods for laboratory propagation from seed of lady's slipper orchid(Cypripedium macranthos Sw.); immature seed which also called green capsule or fully mature seed about 120~130 days from pollination. In green capsule culture, the seed pods should be collected within precisely right time. The right time of seed collection could be diverse under the wether conditions or nutritional factors of the plants. In fully matured seed culture, the more complicated procedures are needed to break the dormancy of the seed; thermal or chemical treatment. The seedlings in this study were easily germinated from immature seeds in Harvais medium; 53 days after pollination(DAP) in Cypripedium pubescens, DAP 65 in C. parviflorum and C. macranthos. The germinated seedlings were transplanted to hormone free media immediately to avoid abnormal growth of seedlings. When the seedlings have roots with a minimum length of around 2-3cm and have visible dormant buds, the seedlings were removed from the flask and stored in refrigerator for vernalization. To examine the correlation of seedlings and maternal plants, the 125 seedlings of C. macranthos were transplanted in the soil bed at a distance of 20-100 cm from mother plants on April 20. The survival rate of seedlings were 92% in 20 cm distance from the ripe plants, and 56 % in 100 cm distance. The seedlings which were transplanted near mother plants showed vigorous growth in plant height, leaf width, and especially dormant buds. Considering the existence of mycorrhiza which is a symbiotic association between a fungus and the roots of a orchid vascular, the various fungus from mother plants could affect the growth of the seedlings. These results indicate the possibility of high and stable production and practical industrialization of endangered lady's slipper orchids.

• Research in Plant Disease
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• v.23 no.2
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• pp.186-192
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• 2017

To survey the incidence of plant-parasitic nematode in strawberry nursery, 117 soil samples were collected from main producing area of strawberry nursery plants in 2016. The incidences of two major problematic nematodes such as root-lesion nematodes (Pratylenchus spp.) and root-knot nematodes (Meloidogyne spp.) were 11% and 3%, respectively. Strawberry nurseries using upland soil either in fields or in plastic-houses showed were higher infection rates of Pratylenchus spp. or Meloidogyne spp. than others. On the other hand, a strawberry nursery using pots filled with bed soil in plastic-house was the lowest infection rate with 0%. Phylogenetic relationships and distance analysis were performed for identification of Pratylenchus spp. and Meloidogyne spp. detected from strawberry nurseries. As the results, they were identified as Pratylenchus penetrans, Pratylenchus vulnus and Meloidogyne hapla. Meanwhile, when nursery plants of strawberry infested with P. vulnus transplanted to pots filled with sterilized soil, P. vulnus was detected from soil in pots as 33% frequency. Thus, P. vulnus can be spread through nursery plants of strawberry infested with that. These studies suggested that Pratylenchus spp. and Meloidogyne spp. were ploblematic nematodes in major areas of strawberry nursery plants and P. vulnus could be spread through nursery plants of strawberry.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.137-142
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• 1999

This study was carried out to investigate the effects of bulb size, type of media, depth of planting, and nutrient compositions on sprouting and growth of tissue cultured garlic microbulbs in hydroponic culture. Early and increased sprouting were observed when the microbulbs were transplanted into soil planted in shallow (1 cm in depth), while bulb size and fresh weight of the whole plant increased in deep planting (3 cm in depth). Bulb size have greatly influenced on not only sprouting rate but also plant growth after planting. Large bulbs resulted in high growth rate such as number of leaves, stem width, plant height, and increase in bulb size after planting. It was shown that Oriental nutrient solution (N=0.17, P=0.45, K=1.29, Ca=2.44, and Mg=0.98 me/L) was more effective in sprouting and further growth of microbulbs as compared to Yamazaki solution (N=0.27, P=0.16, K=1.50, Ca=1.36 and Mg=0.78 me/L). Microbulbs grown in mixture of leaf mould + bark + sand or Baroko showed the most vigrous growth.

• Clean Technology
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• v.20 no.1
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• pp.57-63
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• 2014

In this work, we performed the methanation with steam and synthesis gas of a low $H_2/CO$ ratio to develop a process for producing SNG (synthetic natural gas). In this experiment conditions, the water gas shift reaction and the methanation reaction take place at the same time, and insufficient supply of steam might cause the deactivation of the catalyst. Therefore, the reaction characteristics with the amount of steam was performed, and the methanation on syngas containing $CO_2$ of the high concentration were studied. As a result, the temperature in the catalyst bed decreased by the supply of steam, and the methanation and the water gas shift reaction occurred at the same time. Although methane yield slightly decreased at the methanation using syngas containing $CO_2$ of the high concentration, the long-term operation (1,000 h) in the experimental conditions of this study indicates that this condition is suitable for the new commercial scale SNG process.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.105-113
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• 2011

This study was carried out to develop an automatic loading equipment that can load seedling trays on loading position of the seedling bed driving on enclosed-type rail installed for interconnecting each process of raising seedlings in plant factory. The experiment of transferring the seedling tray by monorail pusher was carried out to figure out the required transfer force and problems during push type device of transporting the plastic seedling trays, that has completed its sowing process, which are installed onto the board of different materials. From the results of this experiment, the loading equipment which can exactly load three of the seedling trays orderly on the loading position of the seedling bed was designed and made. When three sowed trays on every board are transferred by pusher with the speed is at 30 cm/s, the maximum peak transfer force with maximum overshooting at initial transient state and the maximum transfer force at stead state are were respectively 32.8 N, 29.4 N on rubber board, 29.7 N, 22.5 N on a wooden board, 26.9 N, 19.6 N on a acrylic board, and 27.6 N, 19.1 N on an iron board. Changes in the transfer force occurred its maximum at the moment when the pusher collided with the tray, after the collision gradually decreased until it became stable. When two or three trays placed it in order of widthwise are transferred, it is occurred the overlapping of the tray's external bracket. The developed automatic loading equipment with PLC controller did not make any operation error through 100 times of tests, its maximum seedling tray loading speed was 2 sec/tray and its maximum error of transferred location of the tray was 0.5 cm.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.580-586
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• 2009

In this study, co-combustion characteristics of Chinese bituminous coal and North Korean anthracite were investigated using a 2 MWe scale circulating fluidized bed power plant. At first, the combustion efficiency of bituminous coal of China and Australia as a function of excess air ratio and temperature were observed. The results showed that the combustion efficiency was influenced by particle size and volatile content of coal, the combustion efficiency of Chinese bituminous coal was over 99.5%. The unburned carbon particles from fly ash and bottom ash were a content 5~7% and 0.3%, respectively. The combustion efficiency with the mixture ratio 20% of bituminous coal and anthracite decreased over 5% because of the increase of entrained particles by a small average particle size of anthracite in the combustor. However, the outlet concentration of $SO_2$ and $NO_x$ was not changed remarkably. The concentrations of the typical air pollutants such as $NO_x$ and $SO_2$ were 200~250 ppm($O_2$ 6%), 100~320 ppm($O_2$ 6%) respectively. The outlet concentration of $NO_x$ was decreased to 30~65% with $NH_3$ supplying rate of 2~13 l/min in SCR process. The $SO_x$ removal efficiency was up to 70% by in-furnace desulfurization using limestone with Ca/S molar of approximately 6.5. With wet scrubbing using $Mg(OH)_2$ as absorbent, the $SO_x$ removal efficiency reached 100% under near pH 5.0 of scrubbing liquid.

• Journal of Mushroom
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• v.18 no.3
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• pp.208-213
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• 2020

Burkholderia contaminans PSB-A and Burkholderia ambifaria PSB-B were isolated from button mushroom bed to estimate their phosphate solubility. The phosphate-solubilizing abilities of these strains were assessed by measuring the phosphorus content in a single and co-inoculation medium for 7 days. The co-inoculation of these two strains released the highest content of soluble phosphorus (166.3 ㎍ mL^-1) into the medium, followed by single inoculation of B. contaminans PSB-A (143.73 ㎍ mL^-1) and B. ambifaria PSB-B (127.1 ㎍ mL^-1). The highest pH reduction, organic acid production, and glucose consumption were also observed in the co-inoculation medium. According to the plant growth promotion bioassay, co-inoculation enhanced the growth of romaine lettuce much more than the single inoculation (20.4% for leaf widths and 16.6% for root lengths). Although no significant difference was noted between single and co-inoculation of bacterial strains in terms of phosphorous release and plant growth, co-inoculation of PSB may have a beneficial effect on crop growth due to a synergistic effect between the strains.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.271-278
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• 2017

Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants. Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain garden systems having different characteristics were developed and evaluated to determine the optimum design and arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover, the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research will help in the further development and optimization of rain garden systems.

• Clean Technology
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• v.27 no.1
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• pp.61-68
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• 2021

Selective catalytic reduction (SCR) is widely used as a method of removing nitrogen oxide in large-capacity thermal power generation systems. Uniform mixing of the injected ammonia and the inlet flue gas is very important to the performance of the denitrification reduction process in the catalyst bed. In the present study, a computational analysis technique was applied to the ammonia injection system design process of a denitrification facility. The applied model is the denitrification facility of an 800 MW class coal-fired power plant currently in operation. The flow field to be solved ranges from the inlet of the ammonia injection system to the end of the catalyst bed. The flow was analyzed in the two-dimensional domain assuming incompressible. The steady-state turbulent flow was solved with the commercial software named ANSYS-Fluent. The nozzle arrangement gap and injection flow rate in the ammonia injection system were chosen as the design parameters. A total of four (4) cases were simulated and compared. The root mean square of the NH3/NO molar ratio at the inlet of the catalyst layer was chosen as the optimization parameter and the design of the experiment was used as the base of the optimization algorithm. The case where the nozzle pitch and flow rate were adjusted at the same time was the best in terms of flow uniformity.