• The Journal of the Petrological Society of Korea
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• v.18 no.1
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• pp.1-17
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• 2009

This article carried studies of the petrographical and petrochemical characteristics on the Cretaceous volcanic rocks in the area of Janggun peak and Gyemyeong peak which is located at the northeastern area of Mt. Geumjeong, Busan. The areas are composed of andesitic rock, sedimentary rock, rhyolitic rock, and intrusive hornblende, biotite granites, in ascending order. According to petrochemistry, the major elements show the calc-alkaline rock series ranged medium-K to high-K. With increasing $SiO_2$, $Al_{2}O_{3}$, $Fe_{2}O_{3}$, $TiO_2$ CaO, MgO MnO and $P_{2}O_{5}$ are decreased and $K_{2}O$ and $Na_{2}O$ are increased in the volcanic rocks. The trace element compositions show high LILE/HFSE ratios and negative anomaly of Nb, and REE patterns show enrichments in LREE and (-) anomaly values increase of Eu from the basaltic andesite to andesite facies, therefore the volcanic rocks have typical characteristics of continental margin arc calc-alkaline volcanic rocks, produced in the subduction environment. The volcanic rock show nearly the same patterns in spider and REE diagram. Fractional crystallization of the basaltic magma would have produced the calc-alkaline andesitic magma. And the rhyolitic magma seems to have been evolved from the basaltic andesitic magma with fractional crystallization of plagioclase, pyroxene, hornblende, biotite.

• Journal of the Microelectronics and Packaging Society
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• v.2 no.1
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• pp.19-28
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• 1995

RuO2 함량을 각각 달리한 pyrochlore 구조의 Pb2Ru2O6.5분말을 제조하여 이 분말과 유기 vehicle 유기용매를 혼합하여 저항 페이스트를 제조한후 인쇄, 소결과정을 거쳐 전반적 인 물성을 분석하였고 두 종류의 페이스트에 TCR보정용 첨가제로서 ZrO2를 첨가한 경우 처가량에 따라 저항값은 크게 변화하였으나 TCR 은 약간의 변화를 보였으며 Nb2O5의 경우 저항값이 크게 증가하였으며 TCR은 2wt%까지 첨가시 매우 안정적인 값을 나타내었다. 고 정항의 경우 CuO의 첨가시 저항값이 크게 감소 하였으며 TCR은 첨가량에 따라 증가하였 으나 3wt%이상 첨가시 저항체 표면이 심하게 거칠어지는 결과를 보였다.

• Journal of the Korean earth science society
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• v.24 no.4
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• pp.337-345
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• 2003

Surficial sediments from the northern coastal area of Jeju Island, southeastern Yellow Sea (South Sea of Korea) were analyzed for grain-size texture, some geochemical characteristics and clay mineralogy in order to assess their provenance. Rare-earth element compositions and some geochemical discrimination diagrams, especially of Ti/Al, Nb/Al and Rb/Al ratios, were revealed to be useful indices for identifying the origin of sediments. These indices, together with clay mineral compositions, suggest that the coarse-grained sediments originate from the volcanic rocks of Jeju Island, whereas the fine-grained sediments are derived from Chinese rivers, especially the Changjiang River. The oceanic circulation pattern and the physical-chemical properties of seawater in the Yellow and East China seal support the possibility that the fine-pained Changjiang (Yangtze River) sediments can reach the coastal area of Jeju Island (southeastern Yellow Sea).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.1
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• pp.19-23
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• 2018

In a Pb-included piezoelectric composition, $Sr_yPb_{1-y}[(Zn_{1/3}Nb_{2/3})_x-(Ni_{1/3}Nb_{2/3})_{0.2}-(Zr_{0.46}Ti_{0.54})_{0.8-x}]O_3$ was selected in order to attain high piezoelectric properties. According to the PZN ratio (x) and the amount of Sr doping (y), the crystal structure, microstructure and piezoelectric properties were measured and evaluated. In the case of Sr 4 mol% doping, the piezoelectric properties were the highest for a PZN ratio of 0.1. In this condition, the grain size was larger and the intensity was higher. With the PZN ratio fixed and varying the Sr doping, the piezoelectric properties increased until 10 mol% doping and then decreased for over 12 mol% doping. In the case of x＝0.1 and y＝10 mol%, the best piezoelectric properties were obtained, i.e., $d_{33}=660pC/N$ and $k_p=68.5%$, and these values seem to be related to the grain size and crystal structure.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.185-198
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• 2008

Influences of dietary brown seaweed(BSW) on the nutrient metabolism, anti-oxidant enzyme activity and cell-mediated immune response were studied in broiler chicks activated acute phase response. 72 Hatched male broiler chicks(Ross) were divided into 12 pens, 6 heads per pen, and fed the BSW 0.0% (Basal) or 2.0% diet, respectively, and injected with the Salmonella typhimurium lipopoly saccharide(LPS) for activation of the acute phase response three times at 8, 10 and 12 d of age. During 4 wks of experimental feeding, growth performance of broiler chicks was not affected by dietary BSW and the acute phase response. Compared with control birds, the acute phase response did not affect the daily weight gain in birds fed BSW 2.0% diet, decreased nitrogen balance(NB) or metabolizable energy(ME) utilization per metabolic body size(kg0.75), and enhanced activities of peroxidase or extracellular SOD(EcSOD), tumor necrosis factor-alpha and ovotransferrin in plasma and MnSOD and CuZnSOD in erythrocyte cytosol. Compared to BSW 0.0% diet, 2.0% diet enhanced protein retention(NB) per kg0.75 regardless the acute phase response, did not affect uric acid nitrogen excretion(UAN) per kg0.75 in birds during the acute phase response, decreased(p<0.05) the UAN excretion per kg0.75 in control birds. And BSW 2.0% diet also decreased(p<0.05) plasma peroxide level and erythrocyte peroxidase or MnSOD activity but increased plasma peroxidase and EcSOD activity and interleukin-1 activity secreted from LPS-stimulated PBMC in 4 week broiler chicks.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.1
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• pp.5-9
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• 2008

Cordierite has a very low thermal expansion coefficient, but has problem that it has a weak mechanical strength and is apt to be attacked by acid such as sulfur for using as a diesel particulate filter support. The physical properties of $ZrTiO_4$ modified with $SiO_2,\;Al_2O_3$, MoOx, $Cr_2O_3\;and\;Nb_2O_5$ were investigated with XRD, SEM, UTM and thermal expansion, etc. in this paper. $ZrTiO_4$ powder was synthesized as a monoclinic structure with processes that starting materials of $TiO_2\;and\;ZrO_2$ were mixed with ball mill and calcined above $1240^{\circ}C$ for 3 hr. Additive modified $ZrTiO_4$ specimens for flexural strength and thermal expansion measurement were obtained by mixing $ZrTiO_4$ powder with additives, pressing and firing at $1300^{\circ}C$ for 3 hr. The porosity of additive modified $ZrTiO_4$ decreased monotonically with increasing additive content by 5 wt% regardless of additive types and saturated for further increase of additive by 10wt. The flexural strength of $Al_2O_3$ (5, 10 wt%) modified $ZrTiO_4$ shows a large increase, but that of other additives modified $ZrTiO_4$ decreased. The thermal expansion coefficient of additive modified $ZrTiO_4$ except $Nb_2O_5$ decreased continuously with the content of additive. In particular, the lowest thermal expansion coefficient of $ZrTiO_4$ was obtained for the additive of $SiO_2$.

• Analytical Science and Technology
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• v.10 no.6
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• pp.439-444
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• 1997

Twelve kinds (1set) standard materials of chemical ingredients of lead zirconate titanate[$Pb(ZrTi)O_3$] have been developed in order to determine fast and accurate measurement of X-ray fluorescence spectrometry. Especially, we used diluted(ahout sixteen times) filling compound($Li_2B_4O_7/LiBO_2=4/1$) to consider removal effect of matrix, storage convenience, and homogenous characteristics. As a result from the four different laboratories, we obtained extremly good agreement about the standard curve on twelve standard materials which containing eleven elements, PbO, $ZrO_2$, $TiO_2$, SrO, $WO_3$, $La_2O_3$, $Cr_2O_3$, MgO, $Nb_2O_5$, and $MnO_2$. The correlation factor of standard curve was over 0.998. However, ZnO has relatively low correlation factor, 0.977, because the concentration was 10ppm lower than other original materials. This analysis reveals that ZnO has shown the poor linearity as well as low fluorescence intensity. In present work, XRF standard materials are useful for determining a rapid and accurate results for major and minor elements concentration among PZT.

• Journal of Conservation Science
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• v.6 no.1 s.7
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• pp.15-30
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• 1997

The chamical and physical properties of the fragments of an ancient pottery such as earthenware, gliazed pottery and celadon excavated in Chonnam province has been investigated by X-ray diffraction inductively coupled plasma spectroscopy(ICP), thermal mechanical analysis(TMA). Glazed pottery fragments of Chonnam province are cotaining Fe2O3 $4\~7\%$ by the analyis of ICP, firing temperature range was presumed to $1100-1150^{\circ}C$ by TMA. Celadon fragments of Chonnam province are containing Fe2O3 $2\~3\%$ by the analyis of ICP, firing temperature range was presumed to $1140\~1200^{\circ}C$ by TMA. The charateristics in the trace element composition of an ancient pottery of Chonnam provinceis are similar, it is an reflection of similar geological charateristics. The charateristic elements of Chonnam provincical ancient pottery were Rb, Sr, V, Zr, Y, Nd, Sc, La, Ce, Nb, Sm, Eu, Dy and Yb of the analyzed 21 trace elements. By Fe2O3-Zn ditribution diagram, potteries excavated in Yong-am, celadons excavated in Haenam, Kangjin, Buan and glazed pottery excavated in Hae-nam are grouped into the same class.

• Journal of Life Science
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• v.18 no.3
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• pp.344-349
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• 2008

Normal somatic cells proliferate for a limited number of doublings in culture and then enter an irreversible growth-arrest state called replicative senescence. Replicative senescence has been believed a reason for the limited cellular turnover and deterioration of tissue function in aged animals. However, there is no experimental evidence supporting this assumption. Furthermore, cells from aged person have been poorly characterized with an exception of the cases of T cells. In this study, we examined cell biological changes occurring in replicative senescence of fibroblast strains originated from a new-born (NHF-NB) and a 87 year old man (NHF-87). NHF-87 (and the cells from a 75-year old) proliferated to smaller population doublings and with longer doubling times than NHF-NB did. At early passages, NHF-87 exhibited a low senescence-associated ${\beta}-Gal$ (SA ${\beta}-Gal$) activity and lipofuscin level, typical markers for cellular senescence. Furthermore, they maintained low levels of lysosome and reactive oxygen species (ROS). All of these levels increased dramatically in the late passage NHF-87 quite similarly as those in the late passaged NHF-NB did. These results indicate that most cells originated from the aged maintain a phenotype of the cells originated from new-born donors and undergo replicative senescence with the same kinetics as that of the cells from new-born. It is also indicated that not SA ${\beta}-gal$ activity but cell proliferation rate may be qualified as a biomarker for cells aged in vivo.

• The Journal of the Petrological Society of Korea
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• v.9 no.2
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• pp.84-98
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• 2000

Daejeon-sa basalt in the Mt. Juwang area composed of 12 basalt flows alternate with 9 peperites and each basalt and peperite has the variety of thickness. Peperites yielded in Daejeon-sa basalt are mixed of basalt with reddish shale, of which textural type is globular peperite. Basalts yielded in Daejeon-sa basalt are massive basalt without vesicule, although sometimes vesicules are founded in upper within a flow unit. The basalt has mainly pseudomorph of olivine as phenocryst, and also plagioclase and clinopyroxene phenocryst. Matrix is mainly subophitic texture. The plotting result on the TAS diagram shows these basalts belong to the sub-alkaline, and it can be subdivided into calc-alkaline series on the basis of the diagram of Si02 vs. K20 and of alkali index vs. A1203 diagram. According to plots of wt.% oxides vs. wt.% MgO, abundances of A1203 and CaO increase with decreasing MgO while F ~ dOecre~ase . With decreasing MgO compatible elements decrease while incompatible elements increase. In spider diagram of MORB-normalized trace element patterns, HFS elements are nearly similiar with MORB, but LIL elements are enriched. Especially, contents of Ce, F: and Sm are enriched but Nb is depleted. In the chondrite-normalized REE patterns light REEs are enriched than heavy REEs. Tectomagmatic discrimination diagrams shows basalts in the study area are formed in the tectonomagmatic environment of subduction zone under continental margin. This result accord with characters of chemical composition mentioned above. Cr vs. Y diagram and CeM, vs. Ce diagram show that the primary magma of the basalts may formed by the about 15% partial melting of garnet-peridotite in the mantle wedge. After then, Daejeon-sa basalts may formed from evolved magma undergone mainly olivine fractional crystallization and contarnination of crustal materials before eruption.