• 한국유기농업학회지
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• 제19권spc호
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• pp.263-266
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• 2011

Crop protection strategies in organic horticulture aim to prevent insect pest and plant disease problems through utilization of non-chemical based control means. In order to develop a model for management of plant diseases and insects in organic cucumber cultivation, we compared efficacies between chemical pesticide spraying system and biological control means in semi-forcing and retarding cucumber cultivation during 2005 and 2006. Conventional chemical spray program using various chemical pesticides was applied 5 - 10 days intervals, while two different non-chemical pesticide application programs using two formulated biopesticides Topseed$^{TM}$ and Q-fect$^{TM}$, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 1) and using egg-yolk and cooking oil(EYCO), Bordeaux mixture, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 2) were applied 5 - 7 days intervals during entire cucumber cultivation period. Efficacy of both biocontrol agents programs was effective to comparable to conventional chemical pesitice spray program to control plant diseases such as powdery mildew and downy mildew as well as insect pests such as aphids and thrips which are known as major threats in cucumber organic cultivation. In this study, we established and evaluated an effective and economic crop protection strategy using various biological resources can be used to control plant diseases and pests simultaneously in organic cucumber cultivation field.

• 한국초지조사료학회지
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• 제37권3호
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• pp.248-253
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• 2017

Humic acid (HA) is known to consist of various kinds of polymeric organics, their detailed structures can vary depend on sample sources such as organic manure, composts, peat, and lignite brown coal, and largely exists in grassland soils. HA possesses diverse positive effects that not only increase plant growth but also improve soil fertility. Recently, we have manufactured a co-polymeric product of catechol and vanillic acid (CAVA) synthesized artificially, and found that CAVA as a HA mimic increases seed germination and salt tolerance in Arabidopsis. In this study, we examined whether HA or CAVA affects to seedling growth in alfalfa. Foliar application of HA or CAVA increased alfalfa seedling growth including aerial and in root parts. HA or CAVA dramatically enhanced size of leaf and root, whereas HA significantly displayed higher bioactivity than CAVA. Taken together, CAVA acts like as a HA mimic in alfalfa that could apply as an alternation supplement to enhance plant growth and productivity.

• 한국환경과학회지
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• 제16권9호
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• pp.1071-1076
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• 2007

Polychlorinated biphenyls(PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in pine needles of Seoul, and Ansung(GyeongGi-do) to investigate composition, source, and regional concentration of PBDEs. Concentration of total PCBs in Seoul and Ansung showed 608, 945 pg/g DW (mean: 777 pg/g DW), respectively, also concentration of total PBDEs(pg/g DW) in Seoul and Ansung showed 7944, 14,255 pg/g DW(mean 11,100 pg/g DW). Tetrachlorinated biphenyls(Tetra-CBs) and Decabromodiphenyl ethers (Deca-BDE) were detected in relatively high concentration compared to other PBDE congeners in Seoul and Ansung. Correlation coefficients(r) of between PCB congeners in pine needles detected of Seoul and Ansung were significant (r=0.85, p<0.01). It suggested that PCBs concentration in pine needles may originate from secondary sources such as air-plant partition. The similarity of between PBDE congeners profile to those of the technical mixture formulation (Bromkal 70-5DE) suggests a source of this product in these sites.

• 한국작물학회지
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• 제20권
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• pp.122-133
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• 1975

In recent years, farmers have substituted urea for ammonium sulfate as nitrogen fertilizer in their crop production. Since crops can not take urea itself directly as it is, we attempted to determine the amount of decomposition of urea in soil. It was observed that 25 percent of urea which had initially mixed with soil was decomposed in 10 days at 15$^{\circ}C$ and 80 percent in 2 days at $25^{\circ}C$. Therefore, it was considered that large amount of urea could be lost in cool season and cool areas. In the other experiment, ammonium sulfate, as a source of sulfur, was so mixed with urea that the ratio of sulfur to nitrogen would be 15 percent. Small amount of dolomite was also added to this mixture and the resulting fertilizer was applied on the rice plants. Eight percent of yield increase was obtained together with the increased protein content in brown rice.

• 한국농공학회논문집
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• 제52권4호
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• pp.63-71
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• 2010

This study was performed to evaluate the planting properties and root potential of planting block with mixing seeding of herbaceous plants and cool-season grasses in CSG blocks manufactured by cemented sand and materials (CSG) in order to develop environmentally friendly CSG block applied revegetation. Five types of CSG mix designs with cement contents were determined, and the mechanical properties of CSG materials were studied experimentally. To analyze growth properties of plants within CSG block, germination ratio, visual cover, plant height and root potential were measured in four weeks and eight weeks after seeding. The germination regardless mixture seeding of plants and CSG mixproportions started within 4 ~ 7 days after seeding and the germination ratio were in the range of 60 ~ 65 %. The visual cover of kinds of plants evaluated by visual rating system were in the range of 6 ~ 8 in case of seeding the species of cool-season grasses and were in the range of 4 ~ 6 in case of seeding the species of herbaceous plants in four weeks after seeding. The root potential of CSG block with the species of cool-season grasses and herbaceous plants were in the range of $5.7{\times}10^{-3}{\sim}7.7{\times}10^{-3}$ MPa and $2.3{\times}10^{-3}{\sim}6.7{\times}10^{-3}$ MPa in eight weeks after seeding, respectively.

• 대한화학회지
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• 제61권5호
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• pp.244-250
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• 2017

Reduction of (${\pm}$)-3-ketoproline ethyl ester (1) by $NaBH_4$ in the presence of $CaCl_2$ and $MgCl_2$ as the chelating agents gave selective products cis-3(R/S)-alcohols, while reduction by $NaBH_4$ alone or chelated with $NiCl_2$ and $AlBr_3$ gave mixtures of cis- and trans-alcohols. The reduction of (${\pm}$)-1 by various vegetables however, gave exclusively the cis-alcohol as the major and trans-alcohol as the minor. On the contrary, reduction of (${\pm}$)-1 by carrot afforded a mixture of cis- and trans-alcohols, in which the trans-alcohol exists as the major product. In addition, we found that this biocatalyst selectively converted S-enantiomer of (${\pm}$)-1 to the cis-alcohol, and R-enantiomer to a mixture of cis- and trans-alcohols with cis-alcohol as the major product. This fact prompted us to use various fresh plant tissues for stereoselective reduction of diverse types of pyrrolidinones, as its stereoselectivity towards racemic mixtures is higher compared to that using chemical reducing agents.

• 생약학회지
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• 제4권4호
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• pp.193-203
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• 1973

The saponins of two- and four-year-old American ginseng plants (Panax quinquefolium L.) (Araliaceae) collected in July and September were studied. American ginseng saponins (panaquilins) differ from Korean ginseng $(Panax ginseng\;C.A.\;M_{EYER})$ saponins (ginsenosides). The American ginseng saponins separated and named were panaquilins A, B, C, D, E-1, E-2, E-3, G-1, G-2, (c) and (d). One-dimensional thin-layer chromatography did not completely separate panaquilin mixture and was subject to misinterpretation. The panaquilins were more accurately separated and identified by the two-dimensional thin-layer method established. Some differences in American ginseng saponins were dependent upon the plant age, time of collection, and part extracted. The American ginseng sapogenin components are panaxadiol (panaquilins B and C), oleanolic acid (panaquilin D) and panaxatriol (panaquilin G-1). The panaquilins E-1, E-2 and E-3 mixture contained both panaxadiol and panaxatriol. The genins of panaquilins A, (c), (d) and G-2 were not identified. In addition, ${\beta}-sitosterol$ and stigmasterol were identified from the root ether extracts.

• Nuclear Engineering and Technology
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• 제33권2호
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• pp.241-253
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• 2001

Under severe accidents, the pressure and temperature response has an important role for the integrity of a nuclear power plant containment. The history of the pressure and temperature is characterized by the amount and state of steam/air mixture in a containment. Recently, the heat transfer rate to the structure surface is supposed to be increased by the wavy interface formed on condensate film. However, in the calculation by using CONTAIN code, the condensation heat transfer on a containment wall is calculated by assuming the smooth interface and has a tendency to be underestimated for safety. In order to obtain the best- estimate heat transfer calculation, we investigated the condensation heat transfer model in CONTAIN 1.2 code and adopted the new forced convection correlation which is considering wavy interface. By using the film tracking model in CONTAIN 1.2 code, the condensate film is treated to consider the effect of wavy interface. And also, it was carried out to investigate the effect of the different cell modelings - 5-cell and 10-cell modeling - for KNGR(Korean Next Generation Reactor) containment phenomena during a severe accident. The effect of wavy interface on condensate film appears to cause the decrease of peak temperature and pressure response . In order to obtain more adequate results, the proper cell modeling was required to consider the proper flow of steam/air mixture.

• Environmental Engineering Research
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• 제23권3호
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• pp.258-264
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• 2018

The objectives of this research were to 1) isolate and identify thermophilic bacteria for food waste treatment; 2) investigate the capability of food waste treatment using Bacillus species; and 3) develop air-dried Bacillus starters for food waste treatment. Five Bacillus species were isolated from food wastes and identified as Bacillus licheniformis (B. licheniformis) G1, Bacillus circulans C2, Bacillus subtilis (B. subtilis) E1, Bacillus vanillea F1, and Bacillus atrophaeus G2 based on 16S rDNA sequencing. Each identified Bacillus and the mixture of Bacillus species were cultivated in the standard food waste at $45^{\circ}C$ for 8 d. Changes in cell count, solid contents, and pH of the food waste were monitored during cultivation. Air-dried Bacillus cell powders were prepared using wheat flour and lactomil as excipients, and the cell count and survival rate were determined. The cell count of B. licheniformis G1 exhibited the highest number among the tested Bacillus (${\sim}10^8CFU/mL$). The greatest reduction in solid contents of food waste was achieved by B. subtilis E1 (22.6%). The mixture of B. licheniformis G1 and B. subtilis E1 exhibited a synergistic effect on the reduction of solid contents. Lactomil was determined as better excipient than wheat flour based on the greatest survival rate of 95%.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1076-1080
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• 2003

$CO_2$ uptake of vegetation is one of the important variables in order to estimate photosynthetic activity, plant growth and carbon budget estimations. The objective of this research was to develop a new estimation method of $CO_2$ uptake of vegetation based on airborne hyperspectral remote sensing measurements in combination with a photosynthetic rate curve model. In this study, a compact airborne spectrographic imager (CASI) was used to obtain image over a field that had been set up to study the $CO_2$ uptake of corn on August 7, 2002. Also, a field survey was conducted concurrently with the CASI overpass. As a field survey, chlorophyll a content, photosynthetic rate curve, Leaf area, dry biomass and light condition were measured. The developed estimation method for $CO_2$ uptake consists of three major parts: a linear mixture model, an enhanced big leaf model and a photosynthetic rate curve model. The Accuracy of this scheme indicates that $CO_2$ uptake of vegetation could be estimated by using airborne hyperspectral remote sensing data in combination with a physiological model.