• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.102-107
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• 2015

This study was conducted to classify agro-climatic zones in Northeast district of China. For agro-climatic zoning, monthly mean temperature and precipitation data from Global Modeling and Assimilation Office (GMAO) of National Aeronautics and Space Administration (NASA, USA) between 1979 and 2010 (http://disc.sci.gsfc.nasa.gov/) were collected. Altitude and vegetation fraction of East Asia from Weather Research and Forecasting (WRF) were also used to classify them. The criteria of agro-climatic classification were altitude (200 m, between 200-800 m, 800 m), vegetation fraction (60%), annual mean temperature ($0^{\circ}C$), temperature in the hottest month ($22^{\circ}C$), and annual precipitation (700 mm). In Northeast district of China, mean annual temperature, annual precipitation, and solar radiation were $3.4^{\circ}C$, 613.2 mm, and $4,414.2MJ/m^2$ between 2009 and 2013, respectively. Twenty-two agro-climatic zones identified in Northeast district of China by metrics classification method, from which the map of agro-climatic zones for Northeast district of China was derived. The results could be useful as information for estimating agro-meteorological characteristics and predicting crop development and crop yield of Northeast district of China as well as those of North Korea.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.23-29
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• 2009

The hybrid composite materials are recently used in many field as an advanced material due to their high resistance to fracture. However, hybrid composite materials have several problems, especially delamination, compared with homogeneous materials such as an aluminum alloy, etc. In this study, we carried out the tensile test to study the tension failure appearances and tensile ultimate strength of CFRP/Al/CFRP hybrid composite materials. The CFRP material used in the experiment is a commercial material known as CU175NS in unidirectional carbon prepreg. Also Al/CFRP/Al hybrid composites with three kind length of a single edge crack were investigated for the relationship between an aluminium volume fraction and a crack length. The crack length was measured by a traveling microscope under a universal dynamic tester. Futhermore the stress intensity factor behavior was examined according to a volume fraction and an initial crack length ratio to a width.

• Mycobiology
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• v.32 no.4
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• pp.149-154
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• 2004

Toxin produced by Colletotrichum falcatum Went, the incitant of red rot of sugarcane was isolated, purified and assayed to determine host specificity and identify its chemical nature. The toxin was found to be not host specific as it inhibited germination of various seeds(gram, greengram, blackgram, pea, cowpea, rice and sugarcane) as well as different seedlings viz. tomato, coriander, pea and rice. The toxin consists of two distinct fraction-one fraction having $R_f$, value at 0.36 producing identical red rot lesion when inoculated at leaf midrib of sugarcane, and the other having $R_f$, value at 0.72 not showing any red rot lesion. Chromatogram of high performance liquid chromatography(HPLC) of the red rot lesion causing fraction showed a sharp peak at 1.62 min of retention time(RT), and spectral analysis indicated the presence of following chemical $CH_3$ - groups-C-H, C=O, C-N, $-CH_3,\;-CH_2$ -CH and molecular mass of the compound was 203. - ($M^+,\;C_{11}H_{11}N_2O_2$).

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.412-418
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• 2019

Background: Previously, studies have observed that the leaf extract of Cotoneaster wilsonii Nakai has potent antioxidant and anti-inflammatory activites. Therefore, further research was conducted to separate the active antioxidant and anti-inflammatory compounds in the leaf of the C. wilsonii. Methods and Results: The anti-oxidant effects were evaluated by analyzing the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, estimating the totla phenolic content (TPC) and total flavonoid content (TFC), and using reducing power assay method. The ethyl acetate (EtOAc) fraction demonstrated the highest DPPH radical scavenging activity (IC₅₀; 9.69 ㎍/㎖), and the highest TPC and TFC (345.98 mg·GAE/g, and 74.23 mg·QE/g). Moreover, it indicated the highest effects on nitric oxide production. Therefore, the active compound was separated using the EtOAc fraction, determined on the basis of spectral data, and identified as (+)-catechin. Conclusions: The first compound separated was made from the leaf of C. wilsonii was (+)-catechin, which produced potent anti-oxidant and anti-inflammatory effects.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1090-1095
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• 2014

Anthocyanins, a class of flavonoids, are natural water-soluble pigments, which are mainly found in vegetables and fruits. Anthocyanins have attractive pharmacological activities, such as anti-oxidant, anti-inflammatory, anti-cancer, and anti-diabetic. The purpose of this study was to investigate the protective effects of anthocyanins-rich fraction (ANF) from Korean purple sweet potato variety, "Shinjami", against hydrogen peroxide ($H_2O_2$)-induced oxidative stress. In our results, pre-treatment of HepG2 cells with ANF ($10{\mu}g/mL$) significantly prevented cell death and maintained cell integrity, following exposure to 0.9 mM hydrogen peroxide. The $H_2O_2$-dependent production of intracellular ROS was also significantly decreased by pre-treatment with ANF (6 h, $10{\mu}g/mL$). In addition, ANF increased the mRNA levels of antioxidant enzymes, catalase and glutathione level in $H_2O_2$-treated HepG2 cells. These results indicated that ANF protected HepG2 cells against $H_2O_2$-induced oxidative stress by inducing protective system.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.367-372
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• 2008

Cellular protection against carcinogens could be achieved by the induction of phase 2 detoxifying and antioxidant enzymes such as glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO1). Nuclear transcription factor E2-related factor 2 (Nrf2) binds to antioxidant response element (ARE) in the promoter region of these genes and the resulting transactivation occurs. In the present study the effect of gujeolcho (Chrysanthemum zawadskii) roots on the Nrf2-ARE pathway were investigated. C. zawadskii root extract was fractionated with a series of organic solvents and their ability to induce Nrf2-ARE pathway was examined. We separated the most potent dichloromethane (DCM) fraction into 12 sub-fractions and found several sub-fractions with strong effects on the Nrf2-ARE pathway. Fraction 4 strongly induced the ARE-reporter gene activity as well as Nrf2 expression. Sitosterol was isolated as a major compound in fraction 4 although its activity was not as potent as its mother fraction. These results indicate that C. zawadskii roots might be used as a potential natural chemopreventive source.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1357-1364
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• 2000

Our study was performed to evaluate the effect of leaching parameters including the physicochemical characteristics and the fractionated composition of heavy metals on the release of heavy metals in fly ash discharged from MSWI. Leaching parameters such as pH, CEC, particle size, and exchangeable fraction among the fractional composition classified by sequential extraction procedure are considered. The leaching rate of heavy metal released by KSLT method is largely dependent on the pH of fly ash. The effect of pH on the release of heavy metals is different from elements. It appears that the leaching rate of cadmium and copper decreases with increasing pH, while lead and zinc increases at the condition of neutral or strong alkali condition, which suggests that the leaching of heavy metals are limited by the solubility. It is found that the effect of CEC is similarly to that of pH, $D_{10}$ among the particle size of fly ash is negative correlated with the concentration of heavy metals leached by KSLT method. In the case of exchangeable fraction, the leaching rate of heavy metals is linearly correlated with the exchangeable fraction for the fly ash below 40 meq/l00g of CEC, but not related out of the range.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1371-1377
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• 1999

Antimutagenic and antioxidative activities in the different milling fraction of rice(Oryza sativa L., illpumbyeo) were investigated. Twelve milling fractions including embryo, bran(I, II, III, IV and all) and milled rice(I, II, III, IV and V) and were obtained by abrasive milling. Antimutagenic effects of milling fraction against Trp-P-2-induced mutagenicity were shown as ${\approx}0%$ for embryo fraction, $27{\sim}86%$ for bran fractions and $64{\sim}95%$ for milled rice fractions in salmonela typhimurium reversion assay. Milled rice V, inner fraction with 80.9% milling yields, showed the highest antimutagenic activity among milling fractions Antioxidative activity, measured by peroxide value(POV) of different milling fractions was higher in embryo(28%) and bran fractions ($25{\sim}34%)$ than milled rice fractions($6{\sim}22%)$. In terms of thiobarbituric acid(TBA). embryo. bran and milled rice fractions exhibited 14, $5{\sim}21\;and \;6{\sim}20%$ antioxidative activity, respectively. Antioxidative activity, measured by electron donating ability(EDA), was 45% for embryo fraction. $35{\sim}40%$ for bran fractions and $41{\sim}65%$ for milled rice fractions. Antimutagenic activity if milling fractions was correlated with POV (r=-0.471, p<0.01) and EDA (r = 0.609, p<0.001) but not correlated with TBA. Contents of total phenolic acid and SH were higher in bran and embryo fractions than in milled rice fractions, and were reversely correlated with antimutagenic activity (r=-0.523 and -0.451. respectively, p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.274-279
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• 2009

The levels of minerals, amino acids, fatty acids and sugars and antioxidant capacity of Adenophora triphylla (AT) root were investigated. The moisture, crude protein, crude lipid, crude ash and carbohydrate contents of the AT root were $3.4{\pm}0.3,\;9.4{\pm}0.1,\;1.6{\pm}0.1,\;3.7{\pm}0.2$, and $81.9{\pm}0.5$, respectively. Among the minerals present in root, potassium content was the highest. Total amino acid contents were $103.5{\pm}9.1$ mg/g. Palmitic acid was the most abundant fatty acid in AT root. The vitamin E and C levels in AT root were $1.1{\pm}0.1$ and $5.2{\pm}0.5$ mg/100 g, respectively. The antioxidant activity of 70% ethanol extract and fractions of the AT root has been determined by the scavenging of the stable radical DPPH; the result showed that the chloroform fraction was the most active, as the amount required for 50% reduction of DPPH after 30 min ($RC_{50}$) was $103.7{\mu}g$, followed by 70% ethanol extract ($265.4{\mu}g$), hexane fraction ($104.4{\mu}g$), ethyl acetate fraction ($104.4{\mu}g$), butanol fraction ($108.9{\mu}g$) and aqueous fraction ($484.1{\mu}g$).

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1151-1155
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• 2010

Frost depth is one of important factors to design roadway structure, and it can be estimated with numerical simulation on thermal distribution through subgrade soils. Thermal conductivity is a key parameter for accurate prediction on thermal distribution, but there are few studies on thermal conductivity of subgrade soils in Korea. Thermal conductivity can be affected by several factors such as dry density, moisture content, and saturation degree based on previous researches. Two empirical equations to estimate thermal conductivity are applied to access the accuracy of these equations with experimental data. Results indicate that the equation can be used to estimate thermal conductivity with proper quartz fraction.