• Journal of Environmental Science International
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• 제24권1호
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• pp.31-46
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• 2015

In this study, the regional climate (WRF) and air quality (CMAQ) models were used to simulate the effects of future urban growth on surface ozone concentrations in the Seoul metropolitan region (SMR). These analyses were performed based on changes in ozone concentrations during ozone seasons (May-June) for the year 2050 (future) relative to 2012 (present) by urban growth. The results were compared with the impacts of RCP scenarios on ozone concentrations in the SMR. The fractions of urban in the SMR (25.8 %) for the 2050 were much higher than those (13.9 %) for the 2012 and the future emissions (e.g., CO, NO, $NO_2$, $SO_2$, VOC) were increased from 121 % (NO) to 161.3 % ($NO_2$) depending on emission material. The mean and daily maximum 1-h ozone in the SMR increased about 3 - 7 ppb by the effect the RCP scenarios. However, the effect of urban growth reduced the mean ozone by 3 ppb in the SMR and increased the daily maximum 1-h ozone by 2 - 5 ppb over the northeastern SMR and around the coastline. In particular, the ozone pollution days exceeding the 1-h regulatory standard (100 ppb) were far more affected by urban growth than mean values. As a result, the average number of days exceeding the 1-h regulatory standard increased up to 10 times.

• Korean Journal of Pharmacognosy
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• 제38권3호통권150호
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• pp.263-269
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• 2007

Nelumbo nucifera (Nymphaeaceae) has been widely used in a traditional oriental medicine to treat bleeding, fever, diarrhea, hemorrhoid, sunstroke, dysentery and dizziness. The leaves of this plant were refluxed with methanol, and then fractionated with organic solvents to screen the antioxidant activity using DPPH radical. Ethyl acetate and n-butanol fractions showed good DPPH radical scavenging effects and were carried out column chromatographies to isolate nine compounds. Their chemical structures were characterized as p-hydroxybenzoic acid (1), uracil (2), luteolin (3), quercetin $3-O-{\beta}-D-glucopyranoside$ (4), $rhamnetin 3-O-{\beta}-D-glucopyranoside$ (5), $isorhamnetin 3-O-{\beta}-D-glucopyranoside$ (6), $quercetin 3-O-{\beta}-D-glucuropyranoside$ (7), $quercetin 3-O-{\beta}β-D-xylofuranosyl(1{\rightarrow}2)-{\beta}-D-galactopyranoside$ (8), and adenine (9) by comparison NMR spectral data and with those in references. Compounds 1, 2, 5 and 9 were firstly isolated from this plant. Compounds 1, 3 and 4 showed potent DPPH radical scavenging activity. Especially, compound 3, luteolin showed the higher effect than ascorbic acid used as a positive control.

• Journal of the Korean Chemical Society
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• 제40권6호
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• pp.394-400
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• 1996

The conformational transitions of oligopeptide -(HPPHPPP)$_n$- (H: hydrophobic amino acid, P: polar amino acid) which becomes cross linked-dimer are detected at various temperatures, pHs, ionic strengths, and the concentrations of denaturant. In this study, the transitions of oligopeptide due to denaturant, and those due to temperature are theoretically studied. Oligopeptide 20R as chain-dimer and guanidum-HCl as denaturant are used(20R, which contains 10 interchain and /or 10 intrachain electrostatic repulsions). Alpha helix-coil transitions by denaturant are very steep. This shows that the denaturations have transition states of, presumably all helical forms and random coils. The transitions by temperature are smoother than those by the concentration of denaturant. At low temperature the oligopetides which contain long helices exist more than those which contain short helices. As temperature rises, the mole fractions of the partially denatured oligopeptides increase. So the partially denatured oligopeptides are widely distributed at the transition temperature.

• Journal of Ecology and Environment
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• 제37권2호
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• pp.69-79
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• 2014

Soil organic carbon (SOC) in the Arctic is vulnerable to climate change. However, research on SOC stored in the high Arctic regions is currently very limited. Thus, this study was aimed at understanding the distribution and characteristics of SOC with respect to geomorphology and vegetation in Svalbard. In August 2011, soil samples were collected near the Vestre Lov$\acute{e}$nbreen moraine. Sampling sites were chosen according to altitude (High, Mid, and Low) and differences in levels of vegetation establishment. Vegetation coverage, aboveground biomass, and SOC contents were measured, and density-size fractionation of SOC was conducted. The SOC content was the highest in the Mid site ($126.9mg\;g^{-1}$) and the lowest in the High site ($32.1mg\;g^{-1}$), although aboveground biomass and vegetation coverage were not different between these two sites. The low SOC content measured at the High site could be related to a slower soil development following glacial retreat. On the other hand, the Low site contained a high amount of SOC despite having low vegetative cover and a high ratio of sand particles. These incompatible relationships between SOC and vegetation in the Low site might be associated with past site disturbances such as runoff from snow/glacier melting. This study showed that geomorphological features combined with glacier retreat or melting snow/glacier effects could have affected the SOC distribution and vegetation establishment in the high Arctic.

• Journal of fish pathology
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• 제9권2호
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• pp.177-183
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• 1996

A new RNA virus isolated from abnormally swimming behavior has caused mortalities in salmonid fish (Oh et al., 1995 a), A reverse transcriptase (RTase) activity of the virus was determined by using poly r(A) : oligo d(T) as templete : primer. This RTase activity was associated with virus particles of buoyant density of 1.16 g/ml. The virus particles in sucrose fractions were enveloped and were about 85 nm diameter with central electron-dense core. The brain and kidney samples of artificially infected fish showed RTase activity. Virus particle associated proteins about 120, 80, 65, 61, 48, 42, 35, 30, 25, 19, and 15 kDa were observed when examined by polyacrylamide gel electrophoresis analysis. This study showed the presence of a new retrovirus in salmonid fish, which tentatively called RVS (Retrovirus of salmonid).

• Korean Journal of Fisheries and Aquatic Sciences
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• 제35권6호
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• pp.578-582
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• 2002

Ethanol extract obtained from bark, roots, stem, leaves and seeds of 30 species of plants and mushroom, Dicyophora indusiata were examined antimicrobial effect on fish pathogenic bacteria, Listoneria anguillamm, Lactococcus garvieae, Streptococcus iniae by disk method. Ethanol extract of D. indusiata was found to be the most active against all fish pathogenic bacteria in test system. Ethyl acetate fraction from ethanol extract of D. indusiata showed the strongest compared with those from other solvent fractions such as dichloromethane, n-buthanol and water. The antimicrobial effect of ethyl acetate fraction was particularly evident against S. iniae.

• Resources Recycling
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• 제10권6호
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• pp.29-34
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• 2001

Fly ash powders were refined and separated into fine and coarse size by multi-air classification, and each particle was used for synthesizing mullite and zeolite. Mullite was prepared by sintering the mixture of fine fly ash with mean size of 6.5 $\mu$m and $A1_2$$O_3$powder at above $1450^{\circ}C$. Zeolite was synthesized through hydrothermal reaction with coarse fly ash mean size of $56.3\mu$m in 3.5 M NaOH solution at $120^{\circ}C$. The whole range of particle size can be recycled through size classification into fine and coarse fractions, which are used for syntheses of inorganic materials.

• Journal of the Korean School Mathematics Society
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• 제22권3호
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• pp.303-327
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• 2019

This study proposed an integrated approach to multiplication as a way to help students understand multiplication in elementary mathematics. The integrated approach to multiplication is to give students a broad understanding of multiplication by solving a situation of multiplication in a variety of ways in mathematics classes, exploring and discussing each other's methods. The integrated approach to multiplication was derived from a number of previous studies that emphasized various approaches, a consistent approach, and a specific approach to multiplication. As results, the integrated approach of multiplication can be interpreted in four ways as a situation of multiplication, and each method is connected to important characteristics of multiplication emphasized in previous studies. In addition, this study has theoretically confirmed that the integrated approach to multiplication is important not only for multiplication but also for division, fraction and operation of fractions, ratios, rates, and proportions. This study is expected to provide some implications for teachers with regard to multiplication in elementary school mathematics.

• Food Engineering Progress
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• 제15권4호
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• pp.413-419
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• 2011

For producing a high added-value natural seasoning ingredient, a yeast extract (Yx) was supplemented with a rice protein residue fermented with Bacillus licheniformis (Rfl) or with Bacillus subtilis (Rfs). A rice protein residue was obtained after enzymatic hydrolysis of rice protein which was used for preparing a yeast culture medium. Overall acceptabilities of the supplemented yeast extracts (YxRfl or YxRfs) were higher compared to pure yeast extract. Savory taste like umami was found to increase noticeably by adding a fermented rice protein residue to yeast extract, which was confirmed in taste sensor analysis and in sensory test. Beyond the presence of savory tasting amino acids such as Glu and Asp in a fermented rice protein residue, it is assumed that other soluble peptide fractions remained play an important role in enhancing taste of the supplemented yeast extracts. Thus, the yeast extract added with a fermented rice protein residue could be applied to manufacture a natural seasoning ingredient.

• Korean Journal of Environmental Agriculture
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• 제31권4호
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• pp.344-350
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• 2012

BACKGROUND: To design and develop a constructed wetland for effective livestock wastewater treatment, it is necessary to understand the removal mechanisms of various types of pollutants in constructed wetlands. The objective of this study was to evaluate the treatment efficiency of pollutants under different types of fraction in constructed wetland system for treating piggery wastewater. METHODS AND RESULTS: The piggery wastewater treatment plant that consisted of activated sludge tank, aerobic and anaerobic beds was constructed. The concentration of COD(Chemical oxygen demand) in effluent by fraction was 71.5 mg/L for soluble COD, 142 mg/L insoluble COD. The concentration of SS(Suspended solid) in effluent by existing form was 102 mg/L for volatile SS, 15.5 mg/L for fixed SS. The concentration of T-N(Total nitrogen) and T-P(Total phosphorus) in effluent by existing form were 12.8 mg/L and 3.05 mg/L for dissolved form, 35.0 mg/L and 1.93 mg/L for suspended form. The removal efficiencies of COD, SS, T-N and T-P in hot season(summer and autumn) were higher than those in cold season(spring and winter). The removal efficiencies of COD, SS, T-N and T-P in effluent were 98.0, 99.0, 98.2 and 99.2% for all seasons, respectively. CONCLUSION(S): The results indicated that removal types of pollutants were insoluble COD(ICOD), volatile SS(VSS), dissolved T-N(DTN) and dissolved T-P(DTP) in constructed wetlands for treating piggery wastewater.