• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.165-174
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• 2010

The numerical modeling of a coal gasification reaction occurring in an entrained flow coal gasifier is presented in this study. The purposes of this study are to develop a reliable evaluation method of coal gasifier not only for the basic design but also further system operation optimization using a CFD(Computational Fluid Dynamics) method. The coal gasification reaction consists of a series of reaction processes such as water evaporation, coal devolatilization, heterogeneous char reactions, and coal-off gaseous reaction in two-phase, turbulent and radiation participating media. Both numerical and experimental studies are made for the 1.0 ton/day entrained flow coal gasifier installed in the Korea Institute of Energy Research (KIER). The comprehensive computer program in this study is made basically using commercial CFD program by implementing several subroutines necessary for gasification process, which include Eddy-Breakup model together with the harmonic mean approach for turbulent reaction. Further Lagrangian approach in particle trajectory is adopted with the consideration of turbulent effect caused by the non-linearity of drag force, etc. The program developed is successfully evaluated against experimental data such as profiles of temperature and gaseous species concentration together with the cold gas efficiency. Further intensive investigation has been made in terms of the size distribution of pulverized coal particle, the slurry concentration, and the design parameters of gasifier. These parameters considered in this study are compared and evaluated each other through the calculated syngas production rate and cold gas efficiency, appearing to directly affect gasification performance. Considering the complexity of entrained coal gasification, even if the results of this study looks physically reasonable and consistent in parametric study, more efforts of elaborating modeling together with the systematic evaluation against experimental data are necessary for the development of an reliable design tool using CFD method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.195-203
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• 2013

In this study, antioxidative effects of the extracts of different species and flowering periods of Inula britannica were investigated. According to the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of the extracts, The I. britannica var. chinensis flower extract (500 ${\mu}g/mL$) was measured in a 79.89% free radical scavenging activity, but the flower extracts of similar species (I. britannica var. linariaefolia Regel, I. britannica var. ramosa, I. salicina var. asiatica) did not show any effect on the free radical scavenging activity. The effects of the free radical scavenging activity of I. britannica var. chinensis flower extracts were exhibited in the order of full bloom (93.68%), bud (43.28%), and fallen blossom (14.11%). Next, we established optimum condition of extract solvent, temperature, extraction time. The extract from ethanol at $60^{\circ}C$ showed the most free radical scavenging activity among other conditions and extraction time not relevant in free radical scavenging activity. The protective effects of the extract of I. britannica var. chinensis flower on the photohemolysis of human erythrocytes by using rose bengal were increased in a concentration-dependent manner (5 ~ 50 ${\mu}g/mL$). In particular, the extract in 50 ${\mu}g/mL$ concentration exhibited better protective activity (${\tau}_{50}$ = 116.1 min) than (+)-${\alpha}$-tocopherol (${\tau}_{50}$ = 73.44 min), which is a known lipophilic antioxidant. Principle component of I. britannica var. chinensis flower was identified as quercetin of flavonoids by high-performance liquid chromatography (HPLC). These results indicate that the extract of I. britannica var. chinensis flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and $^1O_2$, and protect cellular membranes against ROS. It is concluded that the antioxidative effects of the extract of I. britannica var. chinensis flower could be applicable to functional cosmetics.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.2
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• pp.191-198
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• 2011

In this study, antioxidative effects and inhibitory effects of Geum aleppicum Jacq. extracts on tyrosinase and elastase were investigated. The ethyl acetate fraction of G. aleppicum Jacq. extract ($4.70\;{\mu}g$/mL) showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity (FSC50). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some G. aleppicum Jacq. extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction showed the most prominent ROS scavenging activity ($0.22 \;{\mu}g$/mL). The protective effects of extract/fraction of G. aleppicum Jacq. against the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The G. aleppicum Jacq. extracts suppressed photohemolysis in a concentration dependent manner ($1{\sim}25{\mu}g$/mL), particularly the ethyl acetate fraction exhibited the most prominent celluar protective effect (${\tau}_{50}$, 416.20 min at $10 \;{\mu}g$/mL). The inhibitory effect of G. aleppicum Jacq. extracts on tyrosinase and elastase were investigated to assess their whitening and anti-winkle efficacy. The half maximal inhibitory concentration ($IC_{50}$) of the ethyl acetate fraction on tyrosinase was $95.23\;{\mu}g$/mL. The $IC_{50}$ of 50 % ethanol extract and the ethyl acetate fraction on elastase were $6.27 \;{\mu}g$/mL and $4.31 \;{\mu}g$/mL, respectively. These results indicate that extract/fraction of G. aleppicum Jacq. can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Especially the ethyl acetate fraction of G. aleppicum Jacq. extracts could be applicable to new functional cosmetics for antioxidant, antiaging.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.183-189
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• 2012

In this study, the cellular protective effect and antioxidative property of peanut sprout root extracts were investigated. Cellular protective effects of peanut sprout root extracts on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction of extracts exhibited a cellular protective effect in a concentration dependent manner. Particularly, the aglycone fraction of extracts showed prominent cellular protective effects in a concentration range (5~50 ${\mu}g/mL$). They are more effective than that of (+)-${\alpha}$-tocopherol, known as a lipid peroxidation chain blocker. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of peanut sprout root extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of extracts ($OSC_{50}$; 1.59 ${\mu}g/mL$) showed a similar ROS scavenging activity compare with that of L-ascorbic acid (1.50 ${\mu}g/mL$), known as a strong antioxidant. On the other hand, the order of free radical (1,1-diphenyl-2-picrylhydraxyl, DPPH) scavenging activity ($FSC_{50}$) was (+)-${\alpha}$-tocopherol > 80% MeOH extract > aglycone fraction > ethyl acetate fraction. These results indicate that peanut sprout root extracts can function as an antioxidant in biological systems, particularly skin exposed to solar UV radiation by scavenging $^1O_2$ and other ROS, and to protect cellular membranes against ROS.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.2
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• pp.103-110
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• 1986

The experiments were carried out to study the influence of meteorological factors and cutting management on dry matter accumulation and net energy value in orchardgrass (Dactlylis glomerata L.) cv. Potomac and Baraula, perennial ryegrass (Lolium perenne L.) cv. Reveille and Semperweide and meadow fescue (Festuca pratensis Huds.) cv. Cosmos 11 and N.F.G.. The field trials were designed as a split plot design with three cutting regimes of 6-7 cuts at grazing stage, 4-5 cuts at silage stage and 3 cuts at hat stage in Korea and West Germany from 1975 to 1979. The results obtained are summarized as follows: 1. Productivity of orchardgrass, perennial ryegrass and meadow fescue were mainly affected by cutting systems and meteorological factors, especially air temperature, rainfalls, solar radiation and their interactions. In West Germany, cutting frequency was to be found asan most important factor influenced to dry matter yield and net energy value. 2. Orchardgrass, taken as average of all experimental sites in Korea, produced high yield of 875 kg/10 a in dry matter, which was as much as 32% and 27% higher than those of perennial ryegrass and meadow fescue, respectively. The annual dry matter yields of orchardgrass from 1976 to 1977 were shown a little variation. Dry matter yields in Freising and Braunschweig in West Germany were increased in all grass species continuously. 3. Orchardgrass, perennial ryegrass and meadow fescue showed different response to cutting frequency. The highest dry matter yields were found under 3 cuts at hay stage for orchardgrass and 4-5 cuts at silage stage for perennial ryegrass and meadow fescue. In West Germany, dry matter yields, as average of all grass species under different cutting systems, were 1326 kg, 1175 kg and 1098 kg/10a for 3 cuts, 4-5 cuts and 6-7 cuts, respectively. 4. Chemical composition and net energy concentration of temperate grasses were influenced by cutting managements. The highest yields of digestible crude protein were obtained under 6-7 cuts at grazing stage both in Korea and West Germany. In net energy yields, 3 cutting system produced the highest yield with 694 (orchardgrass), 665 (perennial ryegrass) an 623 kStE/10 a (meadow fescue). However, frequent cutting at grazing and silage stage produced higher yields than 3 cuts at hay stage in Cheju, Suweon and Taekwalyong.

• Journal of Soil and Groundwater Environment
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• v.14 no.2
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• pp.26-32
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• 2009

In this study, the degradation of BTEX (benzene, toluene, ethylbenzene, xylene) was tested in both (Fe$^{3+}$+chelating agent)/H$_2$O$_2$system [Fe(III) 1 mM, oxalate 6 mM, H$_2$O$_2$ 3%, and pH 6] and UV/(Fe3++ chelating agent)lHzOz system [UV dose 17.4 kWhlL, Fe(III) 1mM, oxalate 6 mM,H$_2$O$_2$ 1%, and pH 6]. The types of chelating agents used in experiments were catechol, NTA, gallic, acetyl acetone, succinic, acetate, EDTA, citrate, malonate, and oxalate and the optimum chelating agent for BTEX degradation was determined. The results showed that acetate was the optimum chelating agent for BTEX degradation in both (Fe$^{3+}$+chelating agent)/H$_2$O$_2$ and UV/(Fe$^{3+}$+chelating agent)/H$_2$O$_2$ system, and UV radiation enhanced the degradation of BTEX with any types of chelating agents. Moreover, UV/(Fe$^{3+}$+chelating agent)/H$_2$O$_2$ system, which chelating agent was acetate, removed effectively mixtures of BTEX and MTBE (methyl tert-butyl ether) when the concentration of both BTEX and MTBE was 200 mg/L, respectively. In this system, BTEX was degraded completely and 85% of MTBE was degraded at the reaction time of 180 min. Therefore, UV/((Fe$^{3+}$+chelating agent)/H$_2$O$_2$ system with acetate as a chelating agent removed not only BTEX but also BTEX and MTBE, effectively.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.63-69
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• 2011

In this study, the antibacterial activity and the antioxidative effects, inhibitory effects on tyrosinase of Lespedeza cuneata G. Don extracts were investigated. MIC value of ethyl acetate fraction from L. cuneata G. Don on P. ovale (0.125%) showed that the antibacterial activity of the ethyl acetate fraction was higher than methyl paraben. The aglycone fraction of L. cuneata G. Don (14.63 ${\mu}g$/mL) showed the most prominent the free radical (1,1-diphenyl-2-picryl-hydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of L. cuneata G. Don fraction on $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The aglycone fraction of L. cuneata G. Don (0.07 ${\mu}g$/mL) showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of L. cuneata G. Don on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The L. cuneata G. Don extracts suppressed photohemolysis in a concentration dependent manner (1 ~ 50 ${\mu}g$/mL). The inhibitory effects ($IC_{50}$) of L. cuneata G. Don extracts on tyrosinase were determined with ethyl acetate fraction (104.83 ${\mu}g$/mL) and aglycone fraction (27.55 ${\mu}g$/mL) of L. cuneata G. Don extract. These results indicate that L. cuneata G. Don extract/fractions can function as high potential as bactericide against the pathogenic bacteria and antioxidant in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Extract/fractions of L. cuneata G. Don could be applicable to new functional cosmetics for antiaging, antioxidant, and antibacterial activity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.4
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• pp.309-318
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• 2011

In this study, the antioxidative effect, antibacterial, inhibitory effects on tyrosinase, inhibitory effects on elastase and component analysis of Phellinus linteus (P. linteus) extracts were investigated. The ethyl acetate fraction of P. linteus extracts ($2.94\;{\mu}g/mL$) showed the highest free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of P. linteus extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction ($0.0072\;{\mu}g/mL$) showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of P. linteus extracts on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The P. linteus extracts showed cellular membrane protective effects in a concentration dependent manner ($5{\sim}50\;{\mu}g/mL$). The inhibitory effect ($IC_{50}$) on tyrosinase of P. linteus extract was the highest at 50 % ethanol extract ($6.34\;{\mu}g/mL$), and the inhibitory effect ($IC_{50}$) on elastase of P. linteus was the highest at ethyl acetate fraction ($14.08\;{\mu}g/mL$). TLC, HPLC chromatogram and LC/ESI-MS of the ethyl acetate fraction obtained from P. linteus extracts were identified interfungin A (PL RPT-1a). These results indicate that extract/fractions of P. linteus can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging ROS, and protect cellular membranes against ROS. Extract/fractions of P. linteus can be applicable to new cosmeceuticals for antioxidant, antiaging, antiwrinkle and whitening.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.3
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• pp.225-236
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• 2012

In this study, the cellular protective effects on HaCaT cells and human erythrocytes and antioxidative effects of P. tricuspidata stem extracts were investigated. The ethyl acetate ($50{\mu}g/mL$) and aglycone fraction ($25{\mu}g/mL$) of P. tricuspidata stem extracts doesn't show any characteristics of cytotoxicity. When HaCaT cells were treated with 10 mM $H_2O_2$ and $30{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/mL$) and aglycone ($6.25{\sim}25{\mu}g/mL$) fraction protected the cells against the oxidative damage in a concentration dependent manner. The P. tricuspidata stem extracts showed more prominent cellular protective effect than (+)-${\alpha}$-tocopherol, known as lipid antioxidant at $10{\mu}g/mL$. The ethylacetate fraction of P. tricuspidata stem extracts ($18.5{\mu}g/mL$) showed more free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC5_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of P. tricuspidata stem extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate ($1.72{\mu}g/mL$) and the aglycone fraction ($1.53{\mu}g/mL$) showed similar ROS scavenging activity of L-ascorbic acid ($1.50{\mu}g/mL$). These results indicate that extract/fractions of P. tricuspidata stem extracts can function as natural cytoprotective agents and antioxidants in biological systems, particularly skin exposed to UV radiation by protecting cellular membrane against ROS.

• Analytical Science and Technology
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• v.31 no.4
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• pp.149-160
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• 2018

A large number of functional living products are being produced for eco-friendly or health-promoting purposes. In the manufacturing process, such products could be adulterated with raw materials with high radioactivity, such as monazite and tourmaline. Thus, it is essential to manage raw materials and products closely related to the public living. For proper management, an accurate radioactivity data of the processed products are needed. Therefore, it is essential to develop a rapid and validated analytical method. In this study, the concentration of the radioactive $^{238}U$ and $^{232}Th$ in building materials (e.g., tile, cement, paint, wall paper, and gypsum board) and living products (e.g., health products, textiles, and minerals) were determined and compared by ED-XRF and ICP-MS. By comparing the results of both methods, we confirmed the applicability of the rapid screening and precise analysis of ED-XRF and ICP-MS. In addition, $^{238}U$ and $^{232}Th$ levels were relatively lower in building materials than in living products. Particularly, $^{232}Th$ content in 6 of 47 living products exceeded (maximum $8.2Bq{\cdot}g^{-1}$) the standard limit of $^{232}Th$ content in raw material ($1.0Bq{\cdot}g^{-1}$).