• Electrical & Electronic Materials
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• v.7 no.4
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• pp.281-288
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• 1994

According to spread volume of B(BiPbCuO) layer, composition ratio and each stage of sintering process, we studied stability of high Tc superconductor phase and generation and growth movement of superconducting phase. The dual layer composed of SrCaCuO and BiPbCuO compound were prepared to develop the Bi-2223 superconductor[108K] through interaction and diffusion during sintering process. The dual layer samples were sintered at 830.deg. C for 0-210 hours. From the result, the optimum conditions were : spread volume(A:B=1:0.6), sintering time(210h) and composition ratio(A:S $r_{2}$C $a_{2}$C $u_{2}$- $O_{x}$, B:B $i_{1.9}$P $b_{0.5}$C $u_{3}$ $O_{y}$) at 830.deg. C.. C.C.C.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.597-616
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• 2022

The Chungnam basin is a crucial area for studying the Mesozoic crustal evolutionary history of the Korean Peninsula. This study reports the revised geology and new isotopic ages from the northeastern Chungnam Basin based on detailed geological mapping and LA-ICP-MS zircon U-Pb analysis. Our renewed geologic map defines intra-basin, basin-bounding, and basement fault systems closely related to hydrothermal gold-bearing quartz vein injections. Here, we propose the directions of (micro)structural and geochronological future work to address issues on the relationship between the tectonic process, basin evolution, and hydrothermal fluid migration in the southwestern Korean Peninsula.

• Proceedings of the Petrological Society of Korea Conference
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• 2003.05a
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• pp.55-55
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• 2003

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.31-33
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• 2002

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.77-77
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• 2009

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.74-74
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• 2009

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.75-76
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• 2009

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.314-315
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• 2005

• Korean Journal of Materials Research
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• v.5 no.1
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• pp.36-41
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• 1995

Dielectric properties were investigated at Mn doped $(Pb_{1-x}Ca_{x})ZrO_{3}$ with x=0.38 in microwavefrequencies. Both the density and Q values of sintered ceramics increased with increasing calciningtemperature. In the sample sintered at $1300^{\circ}C$ for 2 hrs, the deped Mn ions completely solubled in $(Pb,Ca)ZrO_{3}$ phase until 0.5wt% and the grain size was independent of doping amount. It was observed thathigh dielectric constant of 90 - 100 and high quality factor of 1300 at 4 GHz for O.l5wt% Mn doped$(Pb_{0.62}Ca_{0.38})ZrO_{3}$. The Mn" and Mn" worked as acceptors in $(Pb,Ca)ZrO_{3}$ which created the oxygen vacancies and affected the increment of the Q values. However, the excess Mn doping more than 0.5wt% resulted in decreasing Q values.decreasing Q values.

• Journal of Animal Science and Technology
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• v.61 no.4
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• pp.225-233
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• 2019

The aim of this study was to produce porcine tetraploid (4N) parthenogenetic embryos using various methods and evaluate their developmental potential. In method 1 (M1), porcine 4N parthenogenetic embryos were obtained by inhibiting extrusion of both first (PB1) and second (PB2) polar bodies; in methods 2 (M2) and 3 (M3), 4N parthenogenetic embryos were obtained by electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 or PB1 extrusion, respectively. We found no differences in the rates of cleavage or blastocyst formation or the proportion of 4N embryos among M1, M2, and M3 groups. The different methods also did not influence apoptosis rates (number of TUNEL-positive cells/number of total cells) or expression levels of apoptosis-related BAX and BCL2L1 genes. However, total cell and EdU (5-ethynyl-2'-deoxyuridine)-positive cell numbers in 4N parthenogenetic blastocysts derived from M1 were higher (p < 0.05) than those for M2 and M3 groups. Our results suggest that, although porcine 4N parthenogenetic embryos could be produced by a variety of methods, inhibition of PB1 and PB2 extrusion (M1) is superior to electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 (M2) or PB1 (M3) extrusion.