• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.113-121
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• 2020

Lots of soil-pavement concrete placed showed a number of problems such as decreasing strength, and durability. In this research, to provide a solution of the problem reported the wasting materials of natural organic lime and magnesia lime were used as a hardener to achieve sufficient performance of soil-pavement concrete. Namely, as a stimulus of blast furnace slag, the natural organic lime and magnesia lime were tested within the mix proportion of 0 to 10 % for each lime to make a new hardener. As a result, in the case of mortar with 1 to 3 % of cement to fine aggregate, 30 % replaced blast furnace slag showed the more favorable results with 5 to 5 % of mix proportion for natural organic lime and magnesia lime.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.44-51
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• 2012

In this study, hardened loess bodies, which did not compose of cement or any chemical binder, were made and tested to evaluate the physical properties such as slump, air content, and compressive strength. Addition of a natural binding material to mixture of loess and lime showed better performance in physical properties. However a lime among natural binding materials is considered as a superior binder to improve the properties of the hardened bodies. According to the experimental results, mixing proportion with 45% of W/B ratio, $285kg/m^3$ of water content, and 60% lime substitution ratio was recommended to acquire the good performance of physical properties for the hardened loess bodies.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.133-142
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• 2004

The purpose of this study is to evaluate a laboratory test on arsenic removal effciency for ARD(Acid Rock Drain-age) using limestone and apatite, and on heavy metals removal efficiencies for AMD(Acid Mine Drainage) using apatite and fish bone. As a result of the laboratory test, pH, arsenic removal rate of limestone & apatite are inversely proportional to flow rates and apatite removes 100% of arsenic while limestone removes 37% of arsenic at 0.6$m{ell}$/min/kg flow rate in case of ARD treatment. And the dissolution amount of apatite is twenty five times higher than that of limestone. In case of AMD treatment, fish bone shows higher dissolution rate than apatite, and pH of outlet water reacted with fish bone is higher than that reacted with apatite. The heavy metal removal rates of fish bone are also higher than that of apatite except arsenic removal rate. The precipitate resulted from fish bone reaction with AMD seems to be biological sludge type while that resulted from apatite with AMD is inorganic solid which can settle easily compared with the biological sludge and can be cemented by gypsum. As the results, apatite can be used as a precipitant for the polluted mine waters showing wide range of pH and fish bone can be used for highly contaminated AMD.

• Research in Plant Disease
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• v.24 no.1
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• pp.33-40
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• 2018

This study was conducted to evaluate the antifungal activity of 19 agro-materials that have been registered for organic cultivation in Korea, after inoculation of pear leaves with Venturia nashicola and Gymnosporangium asiaticum. In V. nashicola, most of the nine agro- materials containing sulfur and copper completely inhibited spore germination, and some of the spores that germinated did not form appressoria. However, in only lime sulfur, Neobordeaux (cupric sulfate), and Wheengaris (sulfur)showed antifungal activity against G. asiaticum. Among the agro-materials containing plant extracts, Wheengarujaba (wood vinegar+spirits+rhubarb) inhibited conidial germination in V. nashicola and G. asiaticum by 100% and 71.6%, respectively. Among the agro-materials containing antifungal microorganisms, Cheongotan (Streptomyces griseus) reduced spore germination rate of V. nashicola to 88.8%; moreover, formation of appressoria or intracellular accumulation was not observed. Application of Topsid (Paenibacillus polymyxa) reduced spore germination rates in V. nashicola and G. asiaticum to 71.0% and 90.6%, respectively, and the formation of appressoria was not observed. Studying the antifungal activity of agro-materials because of cumulative applications under the field conditions is necessary, owing to their contact fungicidal effect and the induced-resistance by microbial metabolites and natural compounds.

• Journal of Life Science
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• v.27 no.12
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• pp.1430-1436
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• 2017

This study assessed the effects of treatment with sap extract from onion residues postharvest and purslane on the quality and quantity of organic onions. At the bending stage, onions treated with the sap extract showed vigorous growth, with higher plant heights, more leaves, and longer sheath lengths than untreated onions. The onion yield was significantly increased when the plant was treated with extracted sap as compared with that of untreated plants (p<0.05). The bulb weight distribution of onions in the mixed onion and purslane treatment was also significantly increased (~300 g) as compared with that of the other treatment (p<0.05). Except for CaO and S, the mineral content of the onions produced from plants treated with the onion and purslane extract mixture was higher than those of onions in the other treatment. The hardness of onions produced from plants treated with the onion and purslane extract was significantly increased (8% and 20%, respectively) as compared with that of onions produced from plants treated with the onion extract only or no treatment (p<0.05). However, there was no significant difference in the sugar contents of the onions produced from extract-treated and nonextract-treated plants. Postharvest, the content of inorganic components (phosphate, calcium, sulfuric acid, and manganese) was higher in soil treated with the onion extract than in soil treated with the onion and purslane extract and non-treated soil. It can be concluded that residues left after onion harvests and purslane extract can be used as natural and environmentally friendly materials for the cultivation of organic onions.

• Journal of Life Science
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• v.24 no.3
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• pp.297-303
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• 2014

The effects of Eisenia bicyclis extracts on osteoblast differentiation and osteoclast formation were investigated. The proliferation of MC3T3-E1 osteoblastic cells was tested in an MTT assay. Treatment with E. bicyclis ethanol extract increased cell proliferation by approximately 128% at a concentration of 10 ${\mu}g/ml$. The ALP activities in the MC3T3-E1 cells was 179% higher when the E. bicyclis ethanol extract was processed at a concentration of 50 ${\mu}g/ml$. The proliferation of RAW 264.7 osteoclastic cells decreased significantly in response to treatment with the E. bicyclis extracts. Moreover, the proliferation of the RAW 264.7 osteoclastic cells treated with E. bicyclis hot water extract decreased by nearly 80%. In addition, the E. bicyclis extract reduced the number of tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cells from osteoclastic RAW 264.7 cells. These results indicate that E. bicyclis extracts have an anabolic effect on bone through the promotion of osteoclast differentiation and suggest that the extracts could be used in the treatment of common metabolic bone diseases.