• The Korean Journal of Mycology
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• v.23 no.4 s.75
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• pp.325-331
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• 1995

The effect of cultural conditions on mycelial growth, polysaccharide production in Phellinus linteus and its monosaccharide composition was studied. P. linteus showed the highest growth (0.9 g/100 ml) on glucose but the polysaccharide production was the highest (13.7%) on mannose. The fungus grew very well at neutral pH (0.9 g/100 ml) but the growth was reduced to 0.47 g per 100 ml at alkaline pH. For the different pH, the yield of polysaccharide was in the range of $5{\sim}8%$. The highest yield of 7.94% was obtained at pH 5. Also a variation in monosaccharide composition was observed for different carbon sources and pH. The composition ranges of glucose, mannose, and galactose of polysaccharide were $80{\sim}95%,\;3{\sim}12%,\;and\;2{\sim}10%$ depending on carbon sources, respectively. In contrast, the variation of composition range of three monosaccharides was narrower for different pH than that for carbon sources. These results suggested the possibility of the improvement of production and the physiological modification of the polysaccharide.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.147-152
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• 2020

In this study, we dedicated to optimize the process for a reactive diluent for epoxy resin of improved chemical resistance by using cardanol, a component of natural oil of cashew nut shell liquid (CNSL). The central composite design (CCD) model of response surface methodology (RSM) was used for the optimization. The quantitative factors for CCD-RSM were the cardanol/ECH mole ratio, reaction time, and reaction temperature. The yield, epoxy equivalent, and viscosity were selected as response values. Basic experiments were performed to design the reaction surface analysis. The ranges of quantitative factors were determined as 2~4, 4~8 h, and 100~140 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. From the result of CCD-RSM, the optimum conditions were determined as 3.33, 6.18 h, and 120 ℃ for the cardanol/ECH reaction mole ratio, reaction time, and reaction temperature, respectively. At these conditions, the yield, epoxy equivalence, and viscosity were estimated as 100%, 429.89 g/eq., and 41.65 cP, respectively. In addition, the experimental results show that the error rate was less than 0.3%, demonstrating the validity of optimization.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.408-414
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• 2019

In this study, an antioxidant was extracted from dandelion leaves using traditional hot water and ultrasonic extraction methods. In order to optimize the extraction yield and total flavonoid, an antioxidant, Box-Behnken design (BBD) model among response surface analysis methods was used. In the case of hot water extraction, the extraction temperature and time as well as the ratio of alcohol/ultrapure water were set as variables, and for the ultrasonic extraction, the ultrasonic survey century and irradiation time and the ratio of alcohol/ultrapure water were variables. Optimum extraction conditions in the hot water extraction method were the extraction temperature and time of $45.76^{\circ}C$ and 1.75 h and the ratio of alcohol/ultrapure water of 41.92 vol.%. While for the ultrasonic extraction method the survey century of 512.63 W, the ratio of alcohol/ultrapure water of 56.97 vol.% and the extraction time of 20.79 min were optimum conditions. Expected reaction yield and flavonoid content values under the optimized condition were calculated as 22.09 wt.% and 28.98 mg QE/mL dw, respectively. In addition, the error value of less than 3% was obtained validating our optimization process.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.31-38
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• 2021

The aim of this study is to evaluate the possibility of treating slaughterhouse by-products using microbial electrolysis cells (MECs). The diluted pig liver was fed to MEC reactors with the influent COD concentrations of 772, 1,222, and 1,431 mg/L, and the applied voltage were 0.3, 0.6, and 0.9 V. The highest methane production of 5.9 mL was obtained at the influent COD concentration of 1,431 mg/L and applied voltage of 0.9 V. In all tested conditions, COD removal rate was increased as the influent COD concentration increased with average removal rate of 62.3~81.1%. The maximum methane yield of 129~229 mL/g COD was obtained, which is approximately 80% of theoretical maximum value. It might be due to the bioelectrochemical reaction greatly increased the biodegradability of pig liver. Future research is required to improve the methane yield and digestibility through optimizing the reactor design and operating conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.4
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• pp.251-258
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• 2020

To investigate the suitable growing area for Italian ryegrass (cv. Kowinearly and cv. Green-Call), we survey the different effects of climatic conditions on plant growth in the east (hereafter termed Yeongdong) and west (hereafter termed Yeongseo) of the passes in Gangwon Province. The Italian ryegrass was grown in Gangneung of Yeongdong and Wonju and Chuncheon of Yeongseo. The plants showed growth differences depending on the cultivated regions between before and after wintering. The Italian ryegrass for pre-wintering showed the relatively long length of plant height in Wonju. While, we observed the relatively tall plants for growing- and harvesting-period after wintering in Gangneung. The increased plant height in Gangneung was closely related to all climatic conditions for the growing period and mean- and lowest-temperature for the harvesting period, respectively. The amount of dry matter was 7,490 kg/ha for Kowinearly and 6,490 kg/ha for Green-Call in Gangneung, which has a higher yield than Chuncheon and Wonju. The relative yield index of dry matter was 77% (Kowinearly) and 78% (Green-Call) in Chuncheon and 84% (Kowinearly) and 71% (Green-Call) in Wonju compared to Gangneung as the standard region. Thus, we suggest that Chuncheon and Wonju are the possible areas for cultivation of Italian ryegrass, considering that Gangneung was the optimum growing area in Gangwon Province.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.311-318
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• 2022

Salicylic acid (SA), a phenolic compound, plays a pivotal role in regulating a wide range of physiological and metabolic processes in plants such as antioxidant cellular defense, photosynthesis, and biotic and abiotic stress responses during the growth and development. We examined the effect of exogenous SA application (100 mg·L^-1) on the growth, yield, photosynthetic characteristics, lipid peroxidation, and antioxidant enzyme activity of chili pepper plants under high temperature and drought stress conditions. SA treatment induced increases of net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) under the stress condition with the highest level after the third treatment. The contents of malondialdehyde and H₂O₂ were significantly lower in the third treatment of SA compared to the control. The activity of ascorbate peroxidase, catalase, peroxidase and superoxide dismutase, increased in treated plants by up to 247, 318, 55 and 54%, respectively compared to the nontreated control. There was no significant difference in the growth characteristics between SA-treated and nontreated plants, while the SA treatment increased marketable yield (kg/10a) by about 15% compared to the nontreated control. Taken together, these results suggest that foliar application of SA alleviates physiological damages caused by the combination of drought and heat stress, and enhances the photosynthetic capacity and antioxidant enzyme activities, thereby improving tolerance to a combination of water deficit and heat stress in chili pepper plants.

• Journal of Practical Agriculture & Fisheries Research
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• v.9 no.1
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• pp.26-32
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• 2007

This study was conducted to determine the regional adaptability of Fagopyrum tataricum in Korea. Suwon, Chunchon, Kangneung, Yonchon and Taean at different experiment sites had soil pH of 6.52, 5.65, 5.7, 5.89 and 5.82, respectively, being at more unfavorable conditions than a recommended soil condition for yam cultivation with pH 5.8~6.7. The amounts of organic matter in Suwon, Chunchon, Taean, and Yonchon were 1.96%, 4.51%, 3.76%, 1.89% and 1.12%, respectively, being at more favorable conditions than a recommended organic matter in soil for yam cultivation with 2.0~3.0%. As the results from cultivating of large plantings in different regions, Suwon showed grain weight in plant of 7.8g. In seed extract analysis, rutin contents were 44.9mg/100g in F. esculentum and 1475.5mg/100g in F. tataricum., respectively.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.64-73
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• 2005

This study was done to determine the regional adaptability of Dioscorea opposita in Korea. Suwon, Chunchon, Kangneung, Yonchon and Taean had soil pH of 6.62, 5.65, 5.9, 5.9 and 5.82, respectively, being at more unfavorable conditions than a standard soil condition for yam with pH 6.2. The amounts of organic matter in Suwon, Chunchon, Taean, and Yonchon were 1.96%, 4.51%, 3.76%, 1.89% and 1.12%, respectively, being at more favorable conditions than a standard organic matter in soil for yam with 2.0~3.0%. As the results from cultivating of large plantings in different regions, Suwon showed the largest the tuber dry weight of 135g. In comparison of general component between round yam and short yam in the area of Kangneung, protein of round yam(3.30%) was higher than that of short yam(1.40%). Dryness in round yam(36.5%) was lower than that of short yam(28.9%), indicating a higher dry weight ratio of round yam. In tuber extracts analysis, saponins content was respectively 23.7mg/g in round yam and 10.4mg/g in short yam.

• Journal of the Korean Society of International Agriculture
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• v.31 no.2
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• pp.178-182
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• 2019

'Muha' is a new strawberry (Fragaria x ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2015. The 'Muha' cultivar originated from a cross between 'Maehyang' and 'Selva' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solid content under long-day and high temperature conditions in 2010. This cultivar was initially named 'Saebong No. 7' after examining its characteristics and productivity in summer culture from 2011 to 2014. After regional adaptability tests in 2015, 'Muha' was selected from Saebong No. 7 as an elite cultivar. The general characteristics of 'Muha' include semispreading type, elliptical leaf, and strength vigor in growth. The fruits are conical in shape, red in color. 'Muha' plants have 18.7 flower clusters, 8.7 more than 'Flamenco' plants. The fruit hardness of 'Muha' and Flamenco' was about the same. The number of fruits of 'Muha' was 37.2, which was 20 higher than that of 'Flamenco'. The marketable yield was 23,981 kg·ha^-1, 159% higher than 'Flamenco'. 'Muha' is suitable for north and highland area of the Southeast Asia as a high hardness and yield cultivar, because it showed continuous flowering habit under long-day and high temperature conditions.

• Composites Research
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• v.37 no.5
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• pp.393-401
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• 2024

Epoxy is a thermosetting polymer with excellent properties such as heat and chemical resistance, making them essential in various industrial fields including electronics. The performance of epoxy is highly dependent on the type of curing agent used. Among them, sulfonium-based latent curing agents are notable for their fast curing speed, high curing hardness, and specificity to certain temperatures, making them attractive for manufacturing anisotropic conductive films in electronic materials where single-component epoxy is required. However, sulfonium-based latent curing agents face challenges in industrial application due to issues with low yield and purity. This study optimized the synthesis conditions for benzyl and naphthyl-type sulfonium curing agents (B-Sul⁺SbF6^-, N-Sul⁺NCyF^-, N-Sul⁺NFSI^-). By adjusting reaction time, reaction temperature, and reactant ratios, yield was maximized, significantly reducing both reaction time and temperature. The three optimized curing agents were evaluated for their thermal and mechanical properties to assess curing behavior and storage stability. The results confirmed that stable curing performance was maintained even after mixing. This study aims to expand the industrial applicability of sulfonium curing agents.