• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.396-407
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• 2023

The golden apple snail (Pomacea canaliculata) has been utilized as a natural and eco-friendly control of weeds in rice paddy fields. However, P. canaliculata can damage other crops. In this study, the effectiveness of plant extracts from various natural sources that are reportedly effective against pests in the control of P. canaliculata was investigated. The four plant extracts were effective against P. canaliculata and ranked in descending order as green tea seed (Camellia sinensis) > root of red spider lily (Lycoris radiata) > leaves of tobacco (Nicotiana tabacum) > root of sophora (Sophora flavescens). The mortality rate of P. canaliculata was increased using 200 to 2000 mg/kg of green tea seed powder. However, shrubby sophora root extract did not significantly increase the mortality rate. The LC₅₀ and LC₉₀ of green tea seed, tobacco leaves, shrubby sophora root, and red spider lily root were 900 and 2800 mg/L, 956 and 2320 mg/L, 2162 and 5325 mg/L, and 512 and 1054 mg/kg, respectively. The LC₅₀ and LC₉₀ of ground powder of C. sinensis, N. tabacum, S. flavescens and L. radiata were 248 and 646 mg/L, 403 and 733 mg/L, 409 and 905 mg/L, and 493 and 1141 mg/L, respectively. The findings indicate the remarkable control potency of green tea seeds against the golden apple snail. An organic material incorporating the four plant powders may help control green apple snail in an ecosystem-friendly manner.

• Membrane Journal
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• v.29 no.3
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• pp.173-182
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• 2019

Much research has been made for finding new and eco-friendly alternative sources of energy to solve the problems related with the pollution caused by emissions of greenhouse gases such as carbon dioxide as the use of fossil fuels increases worldwide. Among them, fuel cells draws particular interests as an eco-friendly energy generator because only water is obtained as a by-product. Anion exchange membrane-based alkaline fuel cell (AEMFC) that uses anion exchange membrane as an electrolyte is of increased interest recently because of its advantages in using low-cost metal catalyst unlike the PEMFC (potton exchange membrane fuel cell) due to the high-catalyst activity in alkaline conditions. The main properties required as an anion exchange membrane are high hydroxide conductivity and chemical stability at high pH. Recently we reported a chemically crosslinked poly(2-dimethyl-1,4-phenylene oxide) (PPO) by reacting PPO with N,N,N',N'-tetramethyl-1,6-hexanediamine as novel anion exchange membranes. In the current work, we further developed the same crosslinked polymer but having enhanced physicochemical properties, including higher conductivity, increased mechanical and dimensional stabilities by using the PPO with a higher molecular weight and also by increasing the crosslinking density. The obtained polymer membrane also showed a good cell performance.

• Korean Journal of Organic Agriculture
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• v.25 no.3
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• pp.631-642
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• 2017

For effective control of insect pest which can outbreak in a field during crop cultivation, various control agents such as eco-friendly agricultural materials (EFAM) including microbial control agents and chemical pesticides have been applied at fields and these control agents may be treated simultaneous or sequential in the same field to suppress diverse pests and diseases. The agents may influence each other and control efficacy may also differ from interactions. Therefore we need to test compatibility of microbial control agents with other agricultural agents. In this study, we investigated influence of pre-treated EFAMs, which are registered for whitefly control in greenhouse, on germination, mycelial growth and control efficacy of Isaria javanica isolate against sweet potato whitefly. The results showed that a mixture of paraffin oil+cinnamon oil among 4 EFAMs highly reduced germination ($8.9{\pm}1.3%{\sim}24.5{\pm}0.9%$) and mycelial growth ($0.81{\pm}0.01cm{\sim}0cm$) of I. javanica. To investigate the effects of the treatment interval between EFAMs and I. javanica on sweet potato whitefly control, four different EFAMs were pre-treated 0, 1, 4, and 7 days before applying I. javanica. Pre-treatment of four EFAMs inhibited insecticidal activity of I. javanica against sweet potato whitefly. Therefore when EFAMs and a mycopesticide using I. javanica spray simultaneous or sequential, application of EFAMs need more than 7 days interval after treatment of mycopesticide at field.

• Composites Research
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• v.36 no.4
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• pp.264-269
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• 2023

Spent coffee grounds (SCG) are a ubiquitous byproduct of coffee consumption, representing a significant waste management challenge, as well as an untapped resource for economic development and sustainability. Improper disposal of SCG can result in environmental problems such as methane emissions and leachate production. This study aims to investigate the physicochemical properties of SCG and their potential as a reinforcement material in polypropylene (PP) to fabricate an eco-friendly composite via extrusion and injection molding, with SCG filler ratios ranging from 5-20%. To evaluate the effect of SCG on the morphological and mechanical properties of the bio- composite, thermogravimetric analysis, SEM, tensile, flexural, and impact tests were conducted. The results demonstrated that the addition of SCG lead to a slight increase in brittleness of the composite but did not significantly affect its mechanical properties. Impressively, the presence of a significant organic component in SCG contributed to the enhanced thermal performance of PP/SCG composites. This improvement was evident in terms of increased thermal stability, delayed onset of degradation, and higher maximum degradation temperature as compared to pure PP. These findings suggest that SCG has potential as a filler material for PP composites, with the ability to enhance the material's properties without compromising overall performance.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.615-621
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• 2018

Recently, various environmentally friendly products have been developed for improving the indoor air quality while pursuing a well-being nature-friendly healthy life as a core value. In this research, we not only solve the problems of existing environmentally friendly paints, but also developed a charcoal composite seats that can reduce radon, which is a natural radioactive substance, and evaluated the reduction effect of radon, formaldehyde and volatile organic compounds. In the charcoal composite seats, a sodium silicate emulsion and charcoal were mixed to prepare an charcoal liquid coating material, and the composite seats was fabricated by air-spray coating method. In order to analyze the hazardous substance reduction performance of the fabricated charcoal composite seats, radon was designed to comply with the Ministry of the Environment standard, formaldehyde and volatile organic compounds were designed to comply with KCL-FIR-1085 standard. As a result of the experiment, the fabricated charcoal composite seats was evaluated as having a radon reduction capability of about 90.8% from 20 hours, formaldehyde and volatile organic compounds were 3 hours, and the reduction capability of 96.7% and 96.6% was found respectively. It is considered that these results can be utilized as basic data at the time of product development for improvement of indoor air quality.

• Journal of the Korea Furniture Society
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• v.26 no.1
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• pp.22-30
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• 2015

In order to prevent decay, distortion, bending, twist on wood products such as wooden furnitures, variety of coating materials were developed and used so far. The coating materials for wood finishing can be synthesized by natural resource or petroleum. However, these coating materials can cause contamination of indoor air quality due to emission of volatile organic compounds (VOCs). In this study, commercialized coating materials for wood finishing such as varnish, coat, and stain were evaluated on emission characteristics of VOCs. Among the varnish, eco-friendly products had about 15~46% lower TVOC emission ($1,042{\mu}g/m^2h{\sim}3,257{\mu}g/m^2h$, respectively, than typical product ($7,100{\mu}g/m^2h$). Natural resource based coating material showed lowest TVOC emission level. However, one of natural resource based waterborne stain showed higher TVOC emission level because waterborne stain already contained higher amount of natural VOC. Oil-based stain might not be suitable for indoor use on interior wall and furniture due to exceed amount of TVOC. Based on results, natural resource based coat or waterborne stain are recommenced to use on wood products.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.168-174
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• 2014

It was conducted to evaluate the control efficacy of Bordeaux mixture on pepper anthracnose in vitro and in vivo. The suppressive efficacy of Bordeaux mixture on mycelial growth and spore germination of Colletotrichum acutatum was investigated on PDA, cellophane membranes and pepper fruits, respectively. Furthermore, its control value was evaluated on detached pepper fruits inoculated with C. acutatum by wound and non-wound inoculation method, and in fields. The mycelial growth of C. acutatum JC24 was inhibited by 90.0% on PDA amended with $937{\mu}g\;mL^{-1}$ of Bordeaux mixture. While the spore germination of C. acutatum JC24 was inhibited perfectly on cellophane membranes treated at $187{\mu}g\;mL^{-1}$ of Bordeaux mixture, that on fruits inoculated with the pathogen by wound inoculation and non-wound inoculation method was inhibited by 88.1% and 91.3%, respectively. Although the control value on fruits treated with $937{\mu}g\;mL^{-1}$ of Bordeaux mixture was 17.6% in wound inoculation method, it was 58.8% in non-wound inoculation method. In fields, when Bordeaux mixture was sprayed five times at 14 day-intervals, it showed 55.7% and 61.7% of control value in 2012 and 2013, respectively. We think Bordeaux mixture was able to use as an eco-friendly organic farming material to control pepper anthracnose based on the above-mentioned results.

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.163-171
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• 2017

Brick is not only aesthetically beautiful and emotional material, but also eco-friendly and good building commodity for human health. Nonetheless, the use of brick has declined, due to the difficulty of building high-rise buildings and the limitation of the free form implementation. However, modern society is increasingly interested in environmentally friendly finishing materials for solving environmental problems. From this point of view, the brick architecture is being reexamined as a material to improve the living environment and to provide comfort without destroying nature. In addition, the development of digital technology enables the implementation of various types of masonry method and curved forms. Parametric design is one of the ways to realize the curved forms and various architectural expressions for brick architecture. In this background, the purpose of this study is to develop algorithms that can easily generate curved brick walls through parametric design, enable various pattern designs, and respond to real-time feedback. The details of the study are as follows. First of all, we examine organic architecture, the trend of brick architecture, and the concept of parametric design. Secondly, In order to generate curved surface with complex curvature, major planning factors affecting form generation are examined. Finally, we develop a parametric design method that consists of generating a curved surface for brick arrangement, implementing a parametric algorithm, and generating a curved form using bricks. Consequentially, we propose an algorithm that can maximize the use of ready-made bricks without using cut bricks to design curved walls and present efficient and economical design alternatives.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.293-297
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• 2022

Korean thistle (Cirsium setidens Nakai), also called Gondre, is an edible perennial herbaceous plant. A new occurrence of aphids has been confirmed on Korean thistle, which is expected to damage crops. The control effect of organic materials was tested to develop an eco-friendly control method for aphid. Pyrethrins+paraffinic oils exhibited a 98% control effect, pyrethrins+matrine+pyroligneous acid showed a 95% control effect, and azadirachtin+rotenone was found to have a 75% control effect. Pyrethrins appear to be the most effective; no damage (phytotoxticity) was caused with organic materials spraying.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.128-133
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• 2015

BACKGROUND: Plant extracts have been used as environment friendly agricultural materials for organic farming in South Korea. However safety evaluation on the plant extracts was not properly tested. The aim of this study was to evaluate safety of the extracts from Melia azedarach, Nerium indicum and Coptis chinensis on cultivating rice. METHODS AND RESULTS: Pant extarcts 300-fold diluted were treated on rice, and residues of M. azedarach, N. indicum and C. chinensis were determined. The analytes from the rice samples were detected by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The method was validated, and good linearities ($r^2=0.995-0.998$), specificity, and recoveries were obtained. Limits of detection were 0.01 mg/kg for all of the target compounds. Recoveries were 79.3-118.3% at 0.1 mg/kg and 75.2-111.5% at 0.5 mg/kg. The residue levels were below 0.030 mg/kg for azadirachtin, 0.320 mg/kg for oleandrin and 1.460 mg/kg for berberine. CONCLUSION(S): The extracts of M. azedarach, N. indicum and C. chinensis contained azadirachtin, oleandrin and berberine as an active ingredient, respectively. The residue of three active ingredients dramatically decreased after treatment in all fruits, stems and roots of rice.