• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.357-370
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• 2009

This experiment was conducted to investigate the effects of compost leachate and concentrated slurry on growth of tomato in hydroponic culture. In process of composting, compost leachate was produced water was through a saturated compost heap. The concentrated slurry was produced by filtration and concentration by membrane process. Filtration of pig slurry was necessary to prevent the hose clogging in hydroponics culture. The treatments of this experiment were consisted of seven different liquid fertilizers; compost leachate(CL), concentrated pig slurry (CS), compost leachate+byproduct(CL+BP), concentrated pig slurry+byproduct(CS+BP), compost leachate 50%+nutrient solution50%(CL+NS), concentrated pig slurry 50%+nutrient solution50%(CS+NS) and nutrient solution(NS) for tomato based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0 mS/cm$ in EC. 1. The compost leachate and concentrated pig slurry were low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). 2. Plant height, SPAD value of tomato was highest in the plot of CS+NS, intermediate in CL, CS+BP, and lowest in 100% concentrated pig slurry. 3. The tomato yield of compost leachate plot was 91% compared with inorganic nutrient solution. The compost leachate solution could be used as a nutrition solution of tomato in organic hydroponics. 4. The growth including plant height, SPAD value, fruit number, fruit weight and yield of tomato in the CL 50%+NS 50% was similar in the control. In conclusion, the mixture solution of 50% pig slurry and 50% nutrient solution could be used as a nutrition solution of tomato hydroponic culture.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.587-598
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• 2010

This study was carried out to elucidate the effects of mulching materials on the growth of potato and weed control at the experimental farm of Chungbuk National University from August 9 in 2008 to June 28 in 2009. Tested potato, cv. 'Superior', was grown under the different mulching materials such as pine tree leaf, oak tree leaf, rice straw, rice hull and sawdust, and control(non-mulching). We tested two times with autumn and spring culture season. The obtained results from this study were summarized as follows; There was significantly difference in plant height, stem length, leaf length, leaf weight and tuber weight in pine tree leaf mulching treatment in autumn season among the treatments. The dominant weeds were Echinochioa crus-galli var. fadmerntacca and Cyperus amvuricus in autumn culture season, while were Echinochioa crus-galli var. fadmerntacca and Digitaria sanguinalis in spring culture season. The appearance of weeds in all of mulching treatment was significant reduced compared to control. The soil moisture content was the highest in rice hull mulching treatment, and that of mulching treatments was significantly higher than control. The soil temperature of mulching treatments was lower than that of control by from $1.0^{\circ}C$to $2.8^{\circ}C$ in autumn season and from $0.7^{\circ}C$ to $2.3^{\circ}C$ in spring season. The soil temperature was low in the order of pine tree leaf, rice straw, oak tree leaf, rice hull, sawdust, and control.

• Korean Journal of Organic Agriculture
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• v.17 no.1
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• pp.83-94
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• 2009

This study was carried out to investigate the effect of application of spent mushroom compost(SMC) on soil chemical properties and tomato growth. After the mushroom has been harvested, the SMC contains a lot of organic material, different microorganism and high density of mushroom hypha. SMC of white button mushroom(Agaricus bisporus) contained diverse microorganisms including fluorescent Pseudomonas sp. and actinomycetes. These isolates showed strong antagonistic to bacterial wi1t(Ralstonia solanacearum) and fusarium wi1t(Fusarium oxysporum) of tomato. The growth and sugar content of tomato showed no significant difference with other treatments by stage of maturity. The EC, exchangeable K and Ca contents of the soil during growing stage were increased in comparison to those of farmhouse practice, but available phosphate decreased. Microbial population in the soil in all growing stages showed no significant difference with other treatments, but yield of tomato decreased in some way in comparison to farmhouse practice. As the result of analysis on chemical property of soil and plant growth and yield of tomato, it seems likely that SMC of white button mushroom(Agaricus bisporus) may be used as substitute of practice compost on cultivation of tomato.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.300-305
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• 2007

Soil erosion is one of the most serious problems in alpine upland in Korea. Soil fertility has continuously decreased due to serious soil erosion. To increase soil fertility, new sources of organic matter should be inputted. Therefore, the objectives of this research were to select winter cover crop as new sources of organic matter and to investigate the effect of winter cover crop on soil property changes, major crop productivity (Chinese cabbage, potato) production in highland, and disease occurrence with different cropping systems. Among 17 candidates for winter coverage crop, rye was most suitable due to it's soil covering rate, and over-wintering rate. The optimum sowing period for rye ranged from late August to late September. Soil porosity and organic matter content increased with rye cultivation. Rye cultivation during winter increased amounts of crop (both Chinese cabbage and potato) productivity up to 8%. There was little difference on amount of crop productivity depending on cropping systems such as monoculture (Chinese cabbage or potato) and Chinese cabbage-potato rotation.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.144-150
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• 2011

This study was conducted to investigate the nutrient components and physicochemical properties of general ('Superior') and colored potato. Proximate composition, reducing sugar, free sugars, free amino acids, organic acids, minerals were analyzed, and Hunter color values were measured in the study. 'Rose' and 'Blue' (colored potatoes) contained high levels of reducing sugar, and total free sugar content was greatly different according to varieties. Glutamic acid, arginine and ${\gamma}$-aminobutyric acid were detected to be the three major amino acids in colored potato, and the major organic acids of general potato were oxalic acid, tartaric acid, malic acid and citric acid. All potato contained high level of potassium, calcium and magnesium. The Hunter 'L' value was the highest in 'Jaseo'; Hunter 'a' value was high in 'Blue' and 'Jasim'; Hunter 'b' value was the highest in 'Haryoung'. Overall, colored potato had higher amount of nutrients and physicochemical properties than 'Superior'. Therefore, colored potatoes are expected to be highly valuable items for the development and applications of a functional food. In addition, these results will provide fundamental data for improving sitological value, breeding of new cultivar and promoting of roughage usage.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.587-592
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• 2013

In this study, we prepared pelletized porous carbon adsorbent (PCA) according to the different pyrolysis temperature using activated carbon and polyvinyl alcohol (PVA) as a binder for the removal of toluene, which is one of the representative volatile organic compounds (VOCs). We investigated physical characteristics of PCA using FE-SEM, BET, TGA and evaluated their adsorption capacity for toluene using GC. It was confirmed that the formability of pellets composed of the activated carbon, PVA and solvent of mass mixing ratio was 1 : 0.2 : 0.8 was the most outstanding. Toluene adsorption capacity was evaluated by measuring the maximum time when more than 99% of toluene adsorbed on the pellet. The specific surface area of the adsorbent pyrolyzed at $300^{\circ}C$ was measured as 4.7 times in $941.9m^2/g$ compared to that of the unpyrolyzed pellet. Micropore volume and toluene adsorption capacity of PCA increased fivefold to be 0.30 cc/g and thirteenfold to be 26 hours compared to that of the unpyrolyzed pellet, respectively. These results were attributed to the change of pore size and specific surface area due to the PVA content and the different pyrolysis temperature.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.951-958
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• 2003

Twenty-four cultivars of colored rice seeds were collected inside and outside Korea, and the antioxidant and antimutagenic activity was determined for the solvent-fractionated layers of their bran parts lipid soluble fraction, pigment containing fraction, and pigment component per se. As the serial organic solvent extraction proceeded, the overall tendency of antioxidant activities declined with increased chemical homogeneity of each fraction. This markedly showed the low antioxidativities of the pigment components from LK 1-3-6-12-1-1 and Gillimhukmi. Even all the colored rice cultivars, with considerable antimutagenic activity in 70% ethanolic extract, exhibited mutagenicity when measured with its pigment containing fraction (wx 124-163-45-7-1-1-1 and LKlB-2-1-1 being the strongest). The pigment content in each colored rice seeds decreased in the order of IR 17491-5-4-3-3>LK 1-3-6-12-1-1>LK 1D-2-12-1>RGS No.336, Elwee. In addition, a substantial difference in both chemical composition of the constituents and its amount could be found between the colored rice and cooking rice cultivars. This revealed that, compared to cooking rice, major components of organic solvent fractions from colored rice probably have long hydrocarbon chain moieties.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.421-430
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• 2015

This study was carried out to understand the ecological variations of macrobenthos communities by construction dikes in the subtidal zone of Chonsu Bay. This study analyzed the distribution of benthos, the dominant species, spatial and temporal changes of benthos communities and benthic pollutions in the subtidal zone of Chonsu Bay. A total of 252 species of subtidal macrobenthos with a density of $681ind./m^2$ were studied. In all the seasons, the species diversity was found to be higher near the mouth of the bay. For all the seasons of the year, Lumbrineris japonica was found to be the most dominant species. These dominant species were found to have positive correlations with species diversity and sedimentary parameters such as organic content in sediments. Dominant species of benthos as well as species composition and diversity showed spatial and temporal distribution patterns.Benthic Pollution Index (BPI) values estimated for the stations near the embankment were in the 4~5 levels, which indicates that the organic matter has been polluted. And as for the stations near the mouth of the bay, the BPI values were in the 1~3 levels, which indicates that the organic matter has been relatively less polluted. According to the SAB-curve analysis, the number of transitional point stations became less in the mouth of the bay.

• Clean Technology
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• v.18 no.2
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• pp.170-176
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• 2012

A series of acrylic copolymers containing perfluoroalkyl acrylate were synthesized by 2-step emulsion polymerization of variety of acrylate monomers (ethyl acrylate, butyl acrylate or methyl methacrylate) with perfluoroalkyl ethyl acrylate (PFA) and glycidyl methacrylate (GMA) monomers. This study focused on effects of monomer compositions (the kind of acrylate monomer, contents of PFA and GMA) and composition of surfactants [(sodium dodecyl sulphate/nonylphenol 10mole ethoxylate (NP-10)] and initiator content on the contact angles and surface free energy. It was found that the copolymer having an optimum composition (BA : 87 wt%, GMA : 8.7 wt% and PFA : 4.3 wt%) was shown to be quite surface active [surface free energy : 19.89 mN/m and contact angles : $103.5^{\circ}$ (water) and $78.7^{\circ}$ (methylene iodide)] in the solid state. This result suggests that the optimal copolymer containing fluorinated monomer synthesized in this study have high potential as a low surface energy material, which may have high oil- and water-repellent surface and have been proposed as acrylic syntan for leather and also as soil-resistant/oil and water repellent coating for textiles and wood etc.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.50-60
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• 2008

The majority of the described experimental results deal with relatively pure aluminium. Variations were made in the pretreatment of the aluminum substrates and an investigation was performed on the resulting changes in oxide layer composition and chemistry. Subsequently, the bonding behavior of the surfaces was investigated by using model adhesion molecules. These molecules were chosen to represent the bonding functionality of an organic polymer. They were applied onto the pretreated surfaces as a monolayer and the bonding behavior was studied using infrared reflection absorption spectroscopy. A direct and clear relation was found between the hydroxyl fraction on the oxide surfaces and the amount of molecules that subsequently bonded to the surface. Moreover, it was found that most bonds between the oxide surface and organic functional groups are not stable in the presence of water. The best performance was obtained using molecules, which are capable of chemisorption with the oxide surface. Finally, it was found that freshly prepared relatively pure aluminum substrates, which are left in air, rapidly lose their bonding capacity towards organic functional groups. This can be attributed to the adsorption of contamination and water to the oxide surface. In addition the adhesion of a typical epoxy-coated aluminum system was investigated during exposure to water at different temperatures. The coating was found to quite rapidly lose its adhesion upon exposure to water. This rapid loss of adhesion corresponds well with the data where it was demonstrated that the studied epoxy coating only bonds through physisorptive hydrogen bonding, these bonds not being stable in the presence of water. After the initial loss the adhesion of the coating was however found to recover again and even exceeded the adhesion prior to exposure. The improvement could be ascribed to the growth of a thin oxyhydroxide layer on the aluminum substrate, which forms a new, water-stable and stronger bond with the epoxy coating. Two routes for improvement of adhesion are finally decribed including an interphasial polymeric thin layer and a treatment in boiling water of the substrate before coating takes place. The adhesion properties were finely also studied as a function of the Mg content of the alloys. It was shown that an enrichment of Mg in the oxide could take place when Mg containing alloys are heat-treated. It is expected that for these alloys the (hydr)oxide fraction also depends on the pre-treatment and on the distribution of magnesium as compared to the aluminium hydroxides, with a direct impact on adhesive properties.