• 식물병연구
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• 제13권1호
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• pp.30-33
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• 2007

석량풋콩 품종의 콩밭에서 모자이크 증상이 약하게 나타난 186개의 잎을 채집하여, Cowpea mosaic virus(CPMV)에 대한 ELISA 검정을 하였다. 그 결과 93개의 시료가 양성반응을 보였으며, 이 가운데 55개의 시료는 매우 높은 바이러스 밀도를 나타내고 있었다. 이러한 결과는 석량풋콩 품종의 동부모자이크병은 ELISA 검정, 바이러스 순화, 전자현미경검경 결과와 바이러스 표피 단백질분석 결과 Cowpea mosaic virus에 의한 병해로 확인되었다.

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.89-94
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• 2005

The compression strength of corrugated fiberboard container for packaging the agricultural products rapidly decreases because of various environmental conditions during distribution of unitized products. Among various environmental conditions, the main factors affecting the compression strength of corrugated fiberboard are absorption of moisture, long-term accumulative load, and fatigue caused by shock and vibration. An estimated rate of damage for fruit during distribution is about from 30 to 40 percent owing to the shock and vibration. This study was carried out to characterize the durability of corrugated fiberboard container for packaging the fruit and vegetables under simulated transportation environment. The vibration test system was constructed to simulate the land transportation using truck. After the package with corrugated fiberboard container was vibrated by vibration test system at various experimental conditions, the compression test for the package was performed. The compression strength of corrugated fiberboard container decreased with loading weight and vibrating time. The multiple nonlinear regression equation for predicting the decreasing rate of compression strength of corrugated fiberboard containers were developed using four independent variables such as input acceleration level, input frequency, loading weight and vibrating time. The influence of loading weight on the decreasing rate of corrugated fiberboard container was larger than other variables.

• 한국환경농학회지
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• 제30권2호
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• pp.202-208
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• 2011

BACKGROUD: ${\alpha}$- and ${\beta}$- Endosulfan isomers of endosulfan, an endocrine disrupting chemical, are widely used cyclodiene organochlorine pesticide in worldwide, and it has widespread application in agriculture and can contaminate river-system as runoff from soil or aerial deposition METHOD AND RESULTS: In this study, an attempt was made to isolate an endosulfan degrading fungus from endosulfan-polluted agricultural soil. Through repetitive enrichment and successive subculture in media containing endosulfan and its metabolites as the sole carbon source, a fungus designated KEF-1 was isolated. Based on phylogenetic analysis, strain KEF-1 was assigned to the genus Eutypella. Also, the ITS (internal transcribed spacer) sequences of KEF-1 were submitted to GenBank under accession number EF581006. In potato dextrose broth containing 8 ${\mu}g$/mL endosulfan, strain KEF-1 completely degraded the endosulfanin 12 days. CONCLUSION: These results suggested that Eutypella sp. KEF-1 has potential as a biocatalyst for endosulfan bioremediation

• Food Science and Biotechnology
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• 제18권1호
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• pp.124-129
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• 2009

Antioxidant activities of the extract of red seaweed, Polysiphonia morrowii, were evaluated using several in vitro assay systems. Activity-guided fractionation revealed that the 90% MeOH fraction of the P. morrowii extract exhibited the highest antioxidant activity, and that this fraction had a high total phenolic content ($135.7{\pm}5.0\;mg$ gallic acid/g extract). Therefore, the antioxidant activities of the 90% MeOH fraction against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, reducing power, ferrous chelating, and hydrogen peroxide were investigated. The results revealed that the antioxidant activities of the 90% MeOH fraction were similar and/or superior to that of commercial antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, the ability of the 90% MeOH fraction to inhibit oxidative damage to DNA was assessed by measuring the conversion of the supercoiled pBR322 plasmid DNA to the open circular form. The 90% MeOH fraction was found to significantly protect this hydroxyl radical-induced DNA damage in a dose-dependent manner. Taken together, these findings suggest that the 90% MeOH fraction of P. morrowii extract and/or its constituents has the potential for use as a new bioresource of antioxidants.

• 생명과학회지
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• 제24권1호
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• pp.81-85
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• 2014

산업폐수로부터 분리한 Pseudomonas sp. BCNU 106은 다양한 유기용매를 이용하여 인돌로부터 인디고를 합성할 수 있다. BCNU 106은 높은 수준의 인돌과 다량의 p-xylene, propylbenzene 그리고 mesitylene의 존재 하에서 효과적으로 인디고를 생산했다. 본 연구에서 인디고의 최대수율 조건은 20% (v/w)의 p-xylene과 4 g/l의 인돌인 것으로 확인되었다. 이러한 조건에서 인디고의 수율과 인돌의 전환효율은 각각 315.5 mg/l와 97%로 조사되었다. 그 결과 Pseudomonas sp. BCNU 106은 산업적으로 중요한 인디고 생산을 위한 잠재적인 균주가 될 것으로 판단된다.

• Mycobiology
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• 제34권3호
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• pp.148-150
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• 2006

Karoowia saxeti was recorded during the lichen field expedition in southern part of Korea in 2006. The lichen was found on the rock surface along coastal line. This species was easily recognized by chemistry (K+ yellow) and the presence of isidia. Thallus was saxicolous, subcrustose, more or less lobate at the center with clearly lobed margins, $2{\sim}6\;cm$ broad and pale yellowish green. Thalli lobes were irregular, variable, up to 1.0mm wide, not branched, flat to more or less convex and contiguous to subimbricate. Upper surface of the thalli was continuous, emaculate, moderately isidiate. The isidia was subglobose to cynlindrical, darkening at the tips and unbranched. Low surface of the thalii was black with a spongy rhizoidal and lamellar layer. HPLC analysis proved the presence of stictic acid (K+ yellow), norstictic acid and usnic acid. This is the first record of the species in South Korea.

• Journal of Ginseng Research
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• 제28권1호
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• pp.67-70
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• 2004

인삼 근부병의 생물학적 방제를 위해 인삼 재배토양으로부터 분리된 길항미생물 Bacillu subtilis B-4228을 사용하여 방제효과를 검정하였다. 공시 균주 B-4228과 C. destructans의 대치배양결과, C destructans의 균사가 비정상적인 형태로 팽창하였으며 강한 생장억제력을 보였다. C. destructans에 의해 오염된 이병토를 이용한 pot시험결과, 건전근율이 무처리구에서 20%였으나 공시 균주 B-4228의 처리구는 82%로 높게 나타났고, 이병율(개체 인삼에 대한 뿌리썩음 이병정도의 총합비율)은 무처리의 경우 50.4%였으나 공시 균주 B-4228의 처리구는 6.0%로 낮았다.

• 농업과학연구
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• 제36권1호
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• pp.57-61
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• 2009

The invasive pest Brontispa longissima(Coleoptera: Chrysomelidae), native to Indonesia and Papua New Guinea, has extended its distribution to Australia, Asia and Pacific islands and caused serious leaf damages of the coconut palm Cocos nuciferain the invaded regions. Although biological control using parasitic wasps has successfully reduced population density and leaf damage levels, this pest and its natural enemies have not been efficiently producedin conventional methods using young leaves of C. nucifera. In the present study, we examined suitability of plants easily available in Thailand and Japan for mass rearing of this pest to develop effective mass rearing system of this pest. Mature, green leaves of the palms were also suitable for immature development and adult reproduction of this pest. Since mature leaves of C. nucifera are more abundant and less contaminated with fungus than the unopened leaf buds, mature leaves could be a promising plant diet for mass rearing of B. longissima. Ornamental palms such as Hyophorbe lagenicaulis and Washingtonia filifera were also suitable for immature development and reproduction of B. longissima. Away from palms, the cattail Typha spp. can sustain immature development and adult reproduction of B. longissima. In the area where C. nucifera is rare or not available, W. filifera or Typha spp. would be good food plants for mass rearing of this pest.

• 한국농공학회논문집
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• 제57권6호
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• pp.59-68
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• 2015

Traditional structure analysis method is based on numerical matrix analysis to use the geometries consisting of the structure. The characteristics require a lot of computer memories and computational time. To avoid these weaknesses, new approach to analyze truss structure was suggested by adopting topological load redistribution method. The axial forces to be not structurely analyzed yet against outside loads were redistributed by using nodal equation of equilibrium randomly at each node without constructing global matrix. However, this method could not calculate the axial forces if structure is statically indeterminate due to degree of many indeterminacies. Therefore, to apply the method suggested in this research, all redundancies of truss structure were replaced by unit loads. Each unit load could make the deformation of a whole structure, and a superposition method was finally adopted to solve the simultaneous equations. The axial forces and deflections agreed with the result of commercial software within the relative error of 1 %, whereas in the case that the axial forces are relatively very smaller than others, the relative errors were increased to 2 %. However, as the values were small enough not to be considered, it was practically useful as a structural analysis model. This model will be used for structural analysis of truss type of large structure such as agricultural farming facility.

• 한국농공학회논문집
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• 제57권6호
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• pp.1-7
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• 2015

Most of chloride diffusion models based on finite difference method (FDM) could not express the diffusion in horizontal direction at each elevation. To overcome these weakness, two dimensional chloride ion penetration model based on finite element method (FEM) to be able to combine various multi-physics simultaneously was suggested by introducing moving mesh technique. To avoid the generation of mesh being able to be distorted depending on the relative movement of water level to static concrete, a rectangular type of mesh was intentionally adopted and the total number of meshes was empirically selected. The simulated results showed that the contents of surface chloride decreased following to the increase of elevation in the top part of low sea level, whereas there were no changes in the bottom part of low level. In the DuraCrete model, the diffusion coefficient of splashed zone is generally smaller than submerged zone, whereas the trend of Life365 model is reverse. Therefore, it could be understood that the developed model using moving mesh technique effectively reflects $DuraCrete^{TM}$ model rather than $Life365^{TM}$ model. In the future, the model will be easily expanded to be combined with various multi-physics models considering water evaporation, heat of hydration, irradiation effect of sun and so on because it is based on FEM.