• Tunnel and Underground Space
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• v.9 no.1
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• pp.1-11
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• 1999

A finite element code was developed to analyze coupled thermo-hydro-mechanical phenomena. This code is based on the finite element formulation provided by Noorishad et al. (1984) and Joint behavior was simulated Goodman's joint constitutive model. The developed code was applied for T-H-M coupling analysis for two kinds of shaft models, with a joint or without a joint respectively. For a model without a joint, temperature increased from the shaft wall to outward evidently. The radial displacement showed opposite directions of outward and inward at some distance from shaft wall. For a model with a joint, closure of joint was found due to thermal expansion. The temperature distribution along a joint showed relatively lower than that of rock matrix because of low thermal conductivity and high specific heat of water. And it could be concluded that effects of thermal flow to joint were more than that of hydraulic flow in a rock mass.

• Animal Systematics, Evolution and Diversity
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• v.7 no.2
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• pp.179-188
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• 1991

In order to determine the taxonomic status of Apodemus agrarius chejuensis from Cheju island in Korea, three hundred and eleven samples of eight subspecies of striped field mice (subspecies, agrarius, ningpoensis , pallidior, chevrieri, insulaemus, manchuricus, coreae, and chejuensis of A. agrarius Pallas) in Asia, collected from Turkey , China, Taiwan, , Manchuria, and Koarea, were used. Four external and 27 cranial characters were measured and their measurements were utilized for multivariate analyses such as cluster, principal component, and discriminant analyses. Four forms were revealed . A largest-size from was chejuensis, whereas a large-size form was cheverieri. A medium -size from and a small-size from were coreae and other five subspecies (agrarius , ningpoensis, pallidior, insulaemus, and manchuricus) , respecitvley, but their differences were clinal. A discontinuous gap was revealed between chejuensis (a largest-size from) and six subspecies ( a medium-size from and a small-size form) Although chejuensis appeared to be a distinct species, it is concluded that molecular analyses are necessary in order to describe it as a new species.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.677-683
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• 2005

The aim of this study was to investigate the apoptotic effect and its mechanism on Radix Aconiti (RA) extract in HL-60 human leukemia cell line. RA extract induced apoptosis as confirmed by discontinuous fragmentation of DNA. To clarify the mechanisms on RA extract-induced apoptosis, we examined the caspase-3, -8 enzyme activity and protein levels including Fas, FasL in HL-60 cells. Treatment with RA extracts resulted in the increase of caspase-3 enzyme activity in a time and dose-dependent manners, which was accompanied by the cleavage of poly-(ADP-ribose) polymerase (PARP). This activation of caspase-3 enzyme resulted from cleavage of procaspase-8, which was followed by increases of FasL, Fas protein expression in RA extracts-treated HL-60 cells. In conclusion, RA extract induced apoptosis of HL-60 human leukemia cell line. This results suggest that the apoptotic mechanisms of RA extract on HL-60 cells involved in FasL, Fas activation, procaspase-8 cleavage, activation of caspase-3 and cleavage of PARP. Collectively, these results suggest that RA may be a valuable agent as a anti-cancer drug.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.387-394
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• 1994

To make the genomic DNA probe of Theileria sergenti, the merozoites were purified from bovine erythrocytes. The infected erythrocytes were lysed by Aeromonas hydrophila(Ah-1) hemolysin, and the parasites were isolated by ultracentrifugation on a Percoll discontinuous density gradient. For construction of a T sergenti genomic DNA library, T sergenti DNA was digested with Pstl and the fragments were ligated into the PstI site of pUC19 before transformation of Escherichia coli JM83. Out of thousands of transformants obtained by transformation of E coli JM83 with the genomic library, three plasmids were chosen. The sizes of the inserted DNAs were 2.9kb(2.4kb and 0.5kb) in pKTS1, 4.3kb in pKTS2 and 1.5kb in pKTS3, respectively. The DNA fragments used as probe KTS1(2.4kb), KTS2(4.3kb) and KTS3(1.5kb) were labeled digoxigenin-11-dUTP for the Southern hybridization. In Southern hybridization, all of the probes(KTS1, KTS2 and KTS3) reacted specifically to T sergenti DNA, but not to bovine leucocyte DNA. In order to find out the sensitivities of the digoxigenin-11-dUTP-labeled KTS1 and KTS3 as the probes, purified merozoite DNA and bovine DNA (control) were checked by dot blot hybridization with the probes. Both of the probes, KTS1 and KTS3, detected as minimum amount of 975pg of the T sergenti DNA, but not bovine DNA even to 500ng.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.2 s.120
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• pp.25-30
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• 2007

Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.

• Journal of Korea Water Resources Association
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• v.38 no.5 s.154
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• pp.333-343
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• 2005

The upwind model is well known to simulate shockwaves, but it is rarely applied to natural rivers because of problems caused by the source terms. Although several methods have been developed to deal with the source terms, none of them has been applied to natural rivers. This paper deals with application of the upwind model to the natural river. An implicit upwind model is applied to a hypothetical irregular channel and a natural river with highly irregular bed, width, and hydraulic structures. Different types of the flows including steady-state flow, flood wave, dam-break wave, and bore are simulated to test accuracy and applicability of the implicit upwind model. It is proved that the model can simulate various types of flows in natural rivers with high accuracy and robustness.

• Journal of Powder Materials
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• v.20 no.6
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• pp.405-410
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• 2013

During sintering of Ni-electrode multi-layer ceramic capacitors (MLCCs), the Ni electrode often becomes discontinuous because of its lower sintering temperature relative to that of $BaTiO_3$. In an attempt to retard the sintering of Ni, we introduced passivation of the Ni powder. To find the optimal passivation conditions, a thermogravimetric analysis (TGA) was conducted in air. After passivation at $250^{\circ}C$ for 11 h in air, a nickel oxide shell with a thickness of 4-5 nm was formed on nickel nanoparticles of 180 nm size. As anticipated, densification of the compacts of the passivated Ni/NiO core-shell powder was retarded: the starting temperature of densification increased from ${\sim}400^{\circ}C$ to ${\sim}600^{\circ}C$ in a $97N_2-3H_2$ (vol %) atmosphere. Grain growth was also retarded during sintering at temperatures of 750 and $1000^{\circ}C$. When the sintering atmosphere was changed from wet $99.93N_2-0.07H_2$ to wet $99.98N_2-0.02H_2$, the average grain size decreased at the same sintering temperature. The conductivity of the passivated powder sample sintered at $1150^{\circ}C$ for 8 h in wet $99.93N_2-0.07H_2$ was measured to be $3.9{\times}10^4S/cm$, which is comparable with that, $4.6{\times}10^4S/cm$, of the Ni powder compact without passivation. These results demonstrate that passivation of Ni is a viable means of retarding sintering of a Ni electrode and hence improving its continuity in the fabrication of $BaTiO_3$-based multi-layer ceramic capacitors.

• Journal of Powder Materials
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• v.25 no.2
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• pp.132-136
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• 2018

Core/shell CdSe/ZnS quantum dots (QDs) are synthesized by a microfluidic reactor-assisted continuous reactor system. Photoluminescence and absorbance of synthesized CdSe/ZnS core/shell QDs are investigated by fluorescence spectrophotometry and online UV-Vis spectrometry. Three reaction conditions, namely; the shell coating reaction temperature, the shell coating reaction time, and the ZnS/CdSe precursor volume ratio, are combined in the synthesis process. The quantum yield of the synthesized CdSe QDs is determined for each condition. CdSe/ZnS QDs with a higher quantum yield are obtained compared to the discontinuous microfluidic reactor synthesis system. The maximum quantum efficiency is 98.3% when the reaction temperature, reaction time, and ZnS/CdSe ratio are $270^{\circ}C$, 10 s, and 0.05, respectively. Obtained results indicate that a continuous synthesis of the Core/shell CdSe/ZnS QDs with a high quantum efficiency could be achieved by isolating the reaction from the external environment.

• Economic and Environmental Geology
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• v.18 no.1
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• pp.55-63
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• 1985

Studies based on field observation and laboratory analysis of the littoral sands of beaches in Jeju Island indicate that the shores exhibit a great variation in both the beach geometry and the composition in terms of geological agents. Most of the beaches around the Island are developed in relatively small patches and discontinuous, as the result of intervening sea cliffs and rocky headlands. The sand quality and the dimensions of the beaches in the Island are relatively poor; for example, these beaches are 220~2,780m in length, 41~313m in width, and $7^{\circ}$ steepness in average foreshore slope. According to the textural parameters analysis, the beach sediments in study portion shows medium grained ($average\;1.42{\phi}$), moderately well sorted ($average\;0.65{\phi}$) and negative skewed ($average\;0.34{\phi}$), which seems to reflecting a high energy marine depositional environment. The heavy and light minerals of te beach sediments are composed of quartz, volcanic fragments, Na-Ca feldspar, olivine, augite as major constituents, along with apatite, biotite and other minor components, which originates from the adjacent geology. The content of CaO-MgO in shell fragments of the littoral sands ranged from 4.69~51.96%, suggesting that the high CaO-MgO content in some of the Island's beaches is attributable to geologic environments conducive to the growth of shell organisms and sediments migration. The provenance of the sediments studied are derived predominantly from adjacent continental shelves and/or terrigenous older river portion, Which sediments were transported mostly by rolling or bottom suspension. The depositional environments of the Jeju beaches can be divided into two types: beaches distributed in the North and the Northeastern parts of the Island are dominated by marine enviroment, whereas beaches in the Southwestern portion are characterized by terrigenous agencies.

• The Journal of Engineering Geology
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• v.18 no.3
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• pp.287-295
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• 2008

Rock slope has a variety of irregular discontinuities and represents a discontinuous mass. Rock joint plays an important role of control hydraulic and mechanic movements in the rock mass. These characteristics between hydraulic and mechanic movements at the rock joints could be represent difference. Therefore they are quiet important factor for slope design. In this study the weathered rock slopes were carried out to analysis of slope stability and geophysical survey. The electrical resistivity survey with dipole-dipole array conducted five profiling sites, and SWEDGE and SLIDE for slope stability analysis were applied on 20 rock slopes far assessment of slope stability and understand to geological situations due to the weathering.