• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1478-1484
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• 2009

The antioxidant, antiproliferation, and nitrate synthesis inhibitory effects of Magnolia denudata extracts (ME) were evaluated. The ME was extracted with 70% (v/v) ethanol and fractionated with solvents of hexane, chloroform, ethyl acetate, n-buthanol and aqueous. The ethyl acetate fraction contained the highest phenolic and flavonoid contents of 427.10 mg garlic acid eq/g and 356.05 mg catechin eq/g, respectively. The ethyl acetate fraction showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity with a 50% inhibition concentration ($IC_{50}$) of 0.20 mg/mL and total antioxidant activity was 0.90 mg AA eq/100 mg. From the results of cytotoxic effects of HCT116, NCL-H460, and HepG2 human cancer cells by MTT assay on the ME and its solvent fraction, chloroform fraction showed the highest cytotoxic effect ($IC_{50}$ value: 0.14, 0.37, and 0.41 mg/mL, respectively). Nitrate synthesis inhibitory effect of ME and its solvent fractions on nitric oxide synthase activity in LPS stimulated RAW 264.7 cells were decreased in dose-dependent manners, and $IC_{50}$ value of hexane and chloroform fractions were 0.39 and 0.49 mg/mL, respectively.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.273-277
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• 2023

The biosorption of methylene blue (MB) from aqueous solution was investigated using dried Rhodotorula glutinis as the biosorbent. The effects of pH, initial dye concentration, biosorbent dosage, and kinetic studies were determined to obtain valuable information for biosorption. Results indicated that most of the adsorbed MB bound within 30 minutes of contact and the MB adsorption capacity increased from 21.1 to 101.8 mg/g with the initial MB concentration increased from 50 to 300 mg/L. Additionally, the MB adsorption capacity gradually increased from pH 4.0 to 9.0, reaching its peak at an initial pH of 9.0. As the biomass load was increased from 0.25 to 4.0 g/L, the MB removal efficiency increased from 14.1 to 84.5%. The Langmuir model provided the best fit throughout the concentration range, and the maximum adsorption capacity (q_max) and Langmuir constant (b) were determined to be 135.14 mg/g and 0.026 l/mg, respectively. Furthermore, the biosorbent process of R. glutinis was found to follow pseudo-second-order kinetics and the calculated q_eq,cal value showed good agreement with the experimental q_eq value. Overall, the biosorption of MB by R. glutinis can be characterized as a monolayer, single site type phenomenon, and the rate-limiting step was determined to be the chemical reaction between the adsorbent and the adsorbate.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.332-335
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• 1987

This paper is a continuation of our previous $paper,^1$ and deals with Eq.(1) (see the text), which was theoretically derived in the $paper,^1$$ [{\eta}]^f\; and\; [{\eta}]^0$ is the intrinsic viscosity at stress f and f = O, respectively. Equation (1) predicts how $[{{\eta}}]^f / [{\eta}]^0$ changes with stress f, relaxation time ${\beta}_2$ of flow unit 2 and a constant $c_2$ related with the elasticity of molecular spring of flow unit 2. In this paper, Eq.(1) is applied to a biopolymer, e.g., poly (${\gamma}$-benzyl L-glutamate), and nonbiopolymers, e.g., polyisobutylene, polystyrene, polydimethylsiloxane and cellulose triacetate. It was found that the $c_2$ factor is zero for non-biopolymers while $c_2{\neq}0$ for biopolymers as found $previously.^1$ Because of the non-Newtonian nature of the solutions, the ratio $[{{\eta}}]^f / [{\eta}]^0$ drops from its unity with increasing f. We found that the smaller the ${\beta}_2,$ the larger the $f_c$ at which the viscosity ratio drops from the unity, vice versa.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.319-324
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• 2018

Due to climate change, water shortages and water-related disasters will be serious. Since the damage and frequency of drought are increasing, the importance of water resource management technology is increasing. In this study, we analyzed the amount of greenhouse gas and the environmental impact caused by the production and operation system technologies of movable weir among various water resource management technologies. The research subjects were air inflatable rubber dams widely used in rivers and upright type rubber dams, which are an improvement on the existing rubber type. Each type of dam was studied at sizes of $1,500H{\times}10,000L\;mm$ and $3,000H{\times}20,000L\;mm$, and the two types and two sizes were compared and analyzed. Using life cycle assessment, we examined the environmental impacts using the amount of electricity required for operation and the discretionary amount required for production. In the '$1,500H{\times}10,000L$' dams, the global warming indexes were $9.35E+04kg\;CO_2-eq$. for upright type and $7.36E+04kg\;CO_2-eq$. for inflatable type. At size of '$3,000H{\times}20,000L$' the global warming indexes were $9.09E+05kg\;CO_2-eq$. for upright type and $1.07E+06kg\;CO_2-eq$. for inflatable type. Analysis of the life cycle environmental impact showed that the environmental impact of the air inflatable rubber dam was reduced by 39.8% at '$1,500H{\times}10,000L$' compared to the larger size. At the larger '$3,000H{\times}20,000L$' size, the upright dam showed a 10.1% smaller impact than the air inflatable rubber dam. Selection of water resource management system should consider climate change, not only management purpose and cost. Additional studies and improvements on rubber dam systems should be made.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1405-1411
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• 2013

We investigated the physicochemical characteristics and antioxidant activities of Doragi (Platycodon grandiflorum) at different aging temperatures (60, 70 and $80^{\circ}C$) and for various periods of duration (5, 10, 15, 30 and 50 days). As the temperature and duration were increased, the pH of Doragi water extracts decreased from 5.22 to 4.17, whereas total acidity increased from 0.265 to 0.998 lactic acid eq.%. In addition, browning index went up from 0.092 to 1.002 and 5-hydroxymethylfurfural (HMF) content steeply rose to 50.40 mg/g from its initial zero value with an increase in temperature and duration. The radical scavenging activity of ethanol extracts was enhanced with a rise in temperature and duration as evident from the value of total polyphenol content (0.589 to 2.358 mg/g), DPPH (0.149 to 1.244 mg Trolox eq/g) and ABTS (0.354 to 1.509 mg Trolox eq/g). The correlation between physicochemical characteristics and antioxidant activities was high; the correlation between pH and total acidity showed a r value of -0.910 (P<0.01), whereas between browning index and 5-HMF content, the r value was 0.880 (P<0.01). Total polyphenol content and DPPH and ABTS radical scavenging activity were highly correlated with the r value of 0.885 (P<0.01) and 0.745 (P<0.01), respectively.

• Advances in environmental research
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• v.2 no.4
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• pp.279-290
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• 2013

In this study, a comprehensive model developed to estimate greenhouse gas (GHG) emissions from urban area with low impact development (LID) and its integrated management practices (IMPs). The model was applied to the actual urban area in Asan Tangjeong district (ATD) as a case study. A rainwater tank (1200 ton) among various LID IMPs generated the highest amount of GHG emissions ($3.77{\times}10^5kgCO_2eq$) and led to the utmost reducing effect ($1.49{\times}10^3kgCO_2eq/year$). In the urban area with LID IMPs, annually $1.95{\times}104kgCO_2eq$ of avoided GHG emissions were generated by a reducing effect (e.g., tap water substitution and vegetation $CO_2$ absorption) for a payback period of 162 years. A sensitivity analysis was carried out to quantitatively evaluate the significance of the factors on the overall GHG emissions in ATD, and suggested to plant alternative vegetation on LID IMPs.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.364-368
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• 2014

This study investigated the antioxidant activity of onion peels extracted from onion byproducts by hot water treatment. Hot water extraction of freeze dried onion peel powder was analyzed for total polyphenol content, 2,2'-diphenyl-1-picryllhydrazyl (DPPH), and 2,2'-azino-bis(3-ehtylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, reducing power, oxygen radical absorbance capacity (ORAC). Total polyphenol content was the highest (233.90 mg/g) in onion peel extract mix with ethanol (OPME-1). The DPPH radical scavenging activity ($IC_{50}$), reducing power, and ORAC obtainbed from onion peel extract mix with ethanol precipitation (OPMPE-1) were the highest at 1.15 mg/mL, 1.69 $A_{700}$, and $318,509{\mu}M\;TE/mL$, respectively. The ABTS radical scavenging activity was the highest at 432.78 mg amino acids (AA) eq/g in the OPM. The results of this study suggest that onion peel extracts have marked antioxidant activity, which can have significant health benefits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.14-19
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• 2012

This study was conducted on the antioxidant activity and in vitro anticancer effects of rough rice (Oryza sativa L.) by germination periods. Rough rice was germinated at $37^{\circ}C$ for 8 days and then extracted with 70% ethanol. It was then analyzed for total polyphenol content, reducing power, antioxidant activities, and in vitro anticancer effects. Total polyphenol content increased from 3.12 mg/g for raw rough rice to 4.05 mg/g at 4 days of germination. Also reducing power increased from 0.96 to 1.25 (p<0.05). DPPH radical scavenging activity increased from 29.25% at 0 day to 34.82% at 2 days. ABTS radical scavenging activity increased from 3.05 mg AA eq/100 g at 0 day to 3.84 mg AA eq/100 g at 4 days, and then decreased afterward. The anticancer effect of ethanol extract at 4 days on stomach cancer cell line (AGS) and colon cancer cell line (HCT-116) showed higher values compared with raw rough rice extract. These results suggest that the best germination periods for increasing biological activities may be 3~4 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.201-207
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• 2014

The changes of growth characteristics and antioxidant activity for selection of optimum germinated temperature on common bean (Phaseolus vulgaris L.). Common beans (IT100888, IT102849, and IT231267) were cultivated at $20^{\circ}C$, $23^{\circ}C$ and $25^{\circ}C$ during 5 days of germination. The range of whole length, hypocotyls length, thickness, abnormal germination and yield rate of sprouts was 7.27~27.62 cm, 3.10~18.86 cm, 1.80~2.27 mm, 5.54~18.34% and 205.95~ 618.71%, respectively. Antioxidant activities of common beans with germination temperature investigated. Common beans (IT100888, IT102849, and IT231267) germinated at $20^{\circ}C$, $23^{\circ}C$ and $25^{\circ}C$ during 5 days, and then extracted with 80% ethanol, and analyzed for total polyphenol content, DPPH and ABTS radical scavenging activity. Total polyphenol content increased from 474 mg GA eq/100 g sample for IT231267 to 1364 mg GA eq/g sample for $23^{\circ}C$ of germination. DPPH radical scavenging activity of IT102849 increased from 189mg Trolox eq./100 g sample ($20^{\circ}C$) to 1073mg Trolox eq./100 g sample ($23^{\circ}C$) also ABTS radical scavenging activity of IT234267 increased from 479 mg Trolox eq./100 g sample ($20^{\circ}C$) to 1134 mg AA eq/100 g ($23^{\circ}C$). These results suggest that germination temperature for increasing antioxidant activities may be $23^{\circ}C$.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.115-126
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• 2013

Recently Korea considers the source of biomass burning emissions reflecting national characteristic, so that includes the inventory of emission source but preceding research is rarely implemented in Korea. Therefore, a study on characteristics of greenhouse gas emissions from biomass burning is necessary and it also makes the source management effectively when the climate-atmospheric management system takes effect. In this study, using the manufactured charcoal kiln and the number of experiment was three times to get a reliable experiment result. The sampling time was decided by changing degree in charcoal kiln and charcoal manufacturing process. The results of calculation greenhouse gas emission factor from charcoal kiln were $668g\;CO_2/kg$, $20g\;CH_4/kg$, $0.01g\;N_2O/kg$. Using the emission factor developed in this study, estimate the emissions from charcoal kiln in Korea. The results of calculation were $46,040ton\;CO_2/yr$, $1,378ton\;CH_4/yr$, $0.69ton\;N_2O/yr$ and greenhouse gas emissions applying GWP are as follows. $CH_4$ emissions was $28,947ton\;CO_2eq./yr$, $N_2O$ emissions was $214ton\;CO_2eq./yr$. As a results, Gross emissions of charcoal kiln in Korea was $75,201ton\;CO_2eq./yr$, but the oak used in this study is included to the biomass so emissions of $CO_2$ are excluded. Therefore the net emissions of charcoal kiln in Korea was $29,161ton\;CO_2eq./yr$.