• Asian Journal of Atmospheric Environment
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• v.4 no.2
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• pp.97-105
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• 2010

A quantitative single particle analytical technique, denoted low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize particulate matters collected at two underground subway stations, Jegidong and Yangje stations, in Seoul, Korea. To clearly identify the source of the indoor aerosols in the subway stations, four sets of samples were collected at four different locations within the subway stations: in the tunnel; at the platform; near the ticket office; nearby outdoors. Aerosol samples collected on stages 2 and 3 ($D_p$: $10-2.5\;{\mu}m$ and $2.5-1.0\;{\mu}m$, respectively) in a 3-stage Dekati $PM_{10}$ impactor were investigated. Samples were collected during summertime in 2009. The major chemical species observed in the subway particle samples were Fe-containing, carbonaceous, and soil-derived particles, and secondary aerosols such as nitrates and sulfates. Among them, Fe-containing particles were the most popular. The tunnel samples contained 85-88% of Fe-containing particles, with the abundance of Fe-containing particles decreasing as the distances of sampling locations from the tunnel increased. The Fe-containing subway particles were generated mainly from mechanical wear and friction processes at rail-wheel-brake interfaces. Carbonaceous, soil-derived, and secondary nitrate and/or sulfate particles observed in the underground subway particles likely flowed in from the outdoor environment by human activities and the air-exchange between the subway system and the outdoors. In addition, since the platform screen doors (PSDs) limit air-mixing between the tunnel and the platform, samples collected at the platform at the Yangjae station (with PSDs) showed a marked decrease in the relative abundances of Fe-containing particles compared to the Jegidong station (without PSDs).

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.204-210
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• 2016

Phytochemical investigation of the 80% MeOH extract from the stems of Lagerstroemia indica resulted in the isolation of eighteen compounds; four norsesquiterpenes, fourteen phenolic derivatives. Their chemical structures were characterized by spectroscopic methods to be tachioside (1), isotachioside (2), 2,4,6-trimethoxyphenyl ${\beta}$-D-glucopyranoside (3), gallic acid 4-methyl ether (4), protocatechuic acid (5), gallic acid (6), vanillic acid (7), vanillin (8), 2-methoxy-5-hydroxymethyl-phenyl-1-O-(6"-galloyl)-${\beta}$-D-glucopyranoside (9), 2,4,6-trimethoxyphenol-1-O-${\beta}$-D-(6'-O-galloyl)-glucopyranoside (10), 4-hydroxy-3-methoxyphenyl-1-O-(6'-O-galloyl)-${\beta}$-D-glucopyranoside (11), vomifoliol (12), vomifoliol 9-O-${\beta}$-D-glucopyranoside (13), 6R,9R-3-oxo-${\alpha}$-ionol-9-O-${\beta}$-D-glucopyranoside (14), dihydrophaseic acid 4'-O-${\beta}$-D-glucopyranoside (15), ${\beta}$-hydroxypropiovanillone 3-O-${\beta}$-D-glucopyranoside (16), myrciaphenone A (17), and coumaric acid (18). Compounds 1-5 and 7-18 were isolated for the first time from this plant. Compounds 1-18 were investigated for their antioxidant properties using DPPH and ABTS radical scavenging capacity assay, $Fe^{2+}$ chelating, and FRAP assay. It was found that 4, 6, and 11 possessed the highest antioxidant capacities.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.590-595
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• 2007

It is important to predict the collision behavior of a train consist to improve its crashworthiness. To analyze crash behavior of train, four kinds of methods are mainly used so far. The first is method using multibody dynamics to predict the gross motion of the train set. The second uses 3D FE model to apply the section analysis method in order. The third is used to deduce design specification and evaluate the crashworhiness of a train by using 1D model. The last is to constitute 2D model to check overriding and coupling devices. The train evaluation procedures are so complex that it is difficult to understand or deal with. In this study, VTM for railway train was introduced to simplify the procedures. VTM involves 3D models, 1D models and dynamic components such as suspension and coupling. The method using hybrid concept model makes it possible to do all the things that are mentioned above. To analyze crash behavior tendency of VTM, the model was simulated and the simulation results were discussed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.156-156
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• 2017

In this work, analysis of biocompatible TiO2 oxide multilayer by the XPS depth profiling was researched. the manufacture of the TiO2 barrier-type multilayer was accurately performed in a mixed electrolyte containing HAp, Pd, and Ag nanoparticles. The temperature of the solution was kept at approximatively $32^{\circ}C$ and was regularly rotated by a magnetic stirring rod in order to increase the ionic diffusion rate. The manufactured specimens were carefully analyzed by XPS depth profile to investigate the result of chemical bonding behaviors. From the analysis of chemical states of the TiO2 oxide multilayer using XPS, the peaks are showed with the typical signal of Ti oxide at 459.1 eV and 464.8 eV, due to Ti 2p(3/2) and Ti 2p(1/2), respectively. The Pd-3d peak was split into Pd-3d(5/2) and Pd-3d(3/2)peaks, and shows two bands at 334.7 and 339.9 eV for Pd-3d3 and Pd-3d5, respectively. Also, the peaks of Ag-3d have been investigated. The chemical states consisted of the O-1s, P-2p, and Ti-2p were identified in the forms of PO42- and PO43-. Based on the results of the chemical states, the chemical elements into the TiO2 oxide multilayer were also inferred to be penetrated from the electrolyte during anodic process.The structure characterization of the modified surface were performed by using FE-SEM, and from the result of biological evaluation in simulated body fluid(SBF), the biocompatibility of TiO2 oxide multilayer was effective for bioactive property.

• The Journal of the Petrological Society of Korea
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• v.12 no.1
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• pp.16-31
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• 2003

The granites in the southern Gimcheon area can be divided into two parts, marginal hornblende biotite granodiorite (Mgd) and central biotite granodiorite to granite (Cgd). Mgd and Cgd are gray in color and display gradational contact relations and are mainly composed of coarse-grained and medium-grained rocks, respectively. Mgd has more frequent and larger mafic enclaves than Cgd, and the two granites partly show parallel foliation at thire contact with gneisses. From representative samples of the granites, K-Ar biotite ages of 197∼207 Ma were obtained. Considering the blocking temperature of biotite, it is suggested that the emplacement age of the granitic magma was probably late Triassic. The anorthite contents of plagioclases in Mgd display less variation than those of Cgd, indicating that Mgd crystallized within a narrow range of temperatures. In the Al$\_$total/-Mg diagram, the biotites from the granites plot within the subalkaline field, and the smooth slope indicates differentiation from a single magma. All amphiboles from the granites belong to magnesio-hornblende. The linear trends of major oxides, AFM and Ba-Sr-Rb indicate that Mgd and Cgd were fractionally differentiated from a single granitic magma body crystallizing from the margin inwards. The relations of modal (Qz+Af) vs. Op, K$_2$O vs. Na$_2$O, Fe$_2$ $O_3$ vs. FeO, Fe$\^$+3/(Fe$\^$+3/+Fe$\^$+2/) and K/Rb vs. Rb/Sr show that they belong to I-type and magnetite-series granitic rocks developed by the progressive melting products of fixed sources. REE data, normalized to chondrite value, have trends of enriched LREE and depleted HREE together with weakly negative Eu anomalies.

• Korean Journal of Heritage: History & Science
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• v.36
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• pp.241-266
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• 2003

Glass pieces excavated from Mireuksa Temple dated $7^{th}$ century A.D. were characterized by chemical composition, specific gravity and melting point. Lead isotope ratios of lead glasses were also compared with those of lead ore to attribute which lead ore was delivered for making lead glass. It was known that some lead glasses found in Japan were similar with those of Mireuksa Temple as comparing the data of chemical composition and lead isotope ratios. Characteristics of lead glass from Mireuksa Temple Thirty five glass pieces of Mireuksa Temple were analyzed for five oxides and found that all was lead glass system(PbO-$SiO_2$) with the range of 70~79% for PbO and 20~28% for $SiO_2$. The concentrations of oxides such as $Al_2O_3$, $Fe_2O_3$ and CuO were below 0.4%, 0.3% and 0.9%, respectively. Principal component analysis(PCA) as a statistical method was carried out to classify glasses with the similarities of chemical concentrations. The result of PCA has shown that three groups of glasses were created according to the excavation positions and two major oxides(PbO and $SiO_2$) greatly contributed to the dispersion of glasses on principal component 1(PC1) axis and trace element oxides($Al_2O_3$ and $Fe_2O_3$) for PC2 axis. Most of lead glasses were greenish by the efficacy of iron and copper oxides and some showed yellowish-green. The gravity of lead glasses was about 4.4~5.4 and estimated melting point was near $670^{\circ}C$. Lead isotope ratios of glasses were analyzed and found quite close to a lead ore from the Bupyeong mine in Gyeonggi-do. Comparison with lead glasses found in Japan Lead glasses of Mireuksa Temple were compared with those of Japan on the basis of chemical and physical data. Chemical compositions of Japanese lead glasses dated $7^{th}{\sim}8^{th}$ century A.D. were nearly similar with those of Mireuksa Temple but lead isotope ratios of those were separated into two groups. Three distribution maps of lead ores of Korea, Japan and China with lead isotope ratios were applied for lead glasses found in Japan. The result have shown that the locations of lead glasses from Fukuoka Prefecture coincided with the region of northen part of Korea and similar with those of Mireuksa Temple and lead glasses from Nara Prefecture dated $8^{th}$ century A.D. were located in the region of Japanese lead ore. This research has demonstrated that lead glasses of Mireuksa Temple conveyed to Miyajidake site, Fukuoka Prefecture around $7^{th}$ century A.D. and glass melting pots and glass beads excavated from Nara Prefecture confirmed the first use of Japanese lead ore for production of lead glasses from the end of $7^{th}$ century A.D.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.31-36
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• 1981

These experiments were conducted to investigate some effects of the soil fumigants Dow-fume MC-2, Cylone, TeloneC-17, and D-D on the growth response of the Korea ginseng(two-year old), Panax ginseng C.A. Meyer, and the chemical composition of the plants. Fumigant treatment increased growth of roots, stems, and leaves. The increase of root growth rates ranging from 2.8 to $58.7\%$ in fresh weight and 8.1 to $63.8\%$ in dry weight were observed in the 2-year old ginseng plants grown in the old ginseng soil treated with the different soil fumigants. The chemical analysis of inorganic elements such as N, P, K, Ca, Mg, Na, Fe, Mn, and Zn was made for the roots, stems and leaves of the 2-year old plants. The increases or decreases of content of the elements were observed, and their contents of each of the elements were changed with the kind of fumigants, part of the plants, and soil depth of the fumigant treatments, but their changing tendencies were not steady.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.2
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• pp.95-102
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• 2014

In this paper, a coupling scheme for applying finite element analysis(FEA) programs, such as, LS-DYNA and MIDAS/Civil, to a nonlinear soil structure interaction analysis by the boundary reaction method(BRM) is presented. With the FEA programs, the structure and soil media are discretized by linear or nonlinear finite elements. To absorb the outgoing elastic waves to unbounded soil region as much as possible, the PML elements and viscous-spring elements are used at the outer FE boundary, in the LS-DYNA model and in MIDAS/Civil model, respectively. It is also assumed that all the nonlinear elements in the problem are limited to structural region. In this study, the boundary reaction forces for the use in the BRM are calculated using the KIESSI-3D program by solving soil-foundation interaction problem subjected to incident seismic waves. The effectiveness of the proposed approach is demonstrated with a linear SSI seismic analysis problem by comparing the BRM solution with the conventional SSI solution. Numerical comparison indicates that the BRM can effectively be applied to a nonlinear soil-structure analysis if motions at the foundation obtained by the BRM for a linear SSI problem excluding the nonlinear structure is conservative.

• Journal of Life Science
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• v.14 no.2
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• pp.205-208
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• 2004

The composition of Pleurotus ferulae fruit body (PFF) has been investigated to determine the possible use for medicinal and edible purposes. The nutritional compositions of PFF were as follows; carbohydrate 54.3 g%, crude protein 20.2 g%, moisture 12.5 g%, crude fat 8.0 g% and ash 5.0 g% (w/w). Potassium concentration in PFF was high up to 2,337.0 mg% (w/w) and Mg, Na, Zn, Ca and Fe were followed. There were seventeen amino acids in PFF. The glutamic acid content was high up to 13.65% mol and aspartic acid, glysine, alanine, leucine, arginine, valine and lysine were followed. Since PFF contains major free amino acids such as alanine, phenylalanine, tyrosine and leucine, it will be a favorable food stuff, Vitamin contents of PFF were vitamin A 0.12, vitamin B$_1$ 0.31, vitamin B$_2$ 0.68, vitamin C 7.99, vitamin E 316.88 and vitamin D$_3$ 0.29 mg%. PFF will have a good anti-aging effect due to the high content of vitamin C and E.

• Journal of Life Science
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• v.18 no.3
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• pp.350-356
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• 2008

Biochemical characterization including hemagglutination of erythrocytes, molecular weight, optimum temperature, thermal stability, optimum pH, carbohydrate specificity, and inhibitory effect of metal ion were studied in lectin of eggplant (Solanum melongena L.) fruit prepared by ammonium sulfate fractionation and affinity chromatography. This lectin was agglutinated by trypsin-treated rat blood erythrocyte. The molecular weight of this lectin by SDS-PAGE was estimated to be approximately 19.3 kDa of a single band. This lectin has no activity by 7 carbohydrates containing D-glucose. The optimum range of temperature and pH were $10-20^{\circ}C$ and pH 6.2-7.2, respectively. This lectin was relatively stable at $20-70^{\circ}C$. And the activity of this lectin was not inhibited by $Ca^{2+},\;Co^{2+},\;Cu^{2+},\;Fe^{2+},\;Mg^{2+}$, and $Mn^{2+}$.