• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.1-5
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• 2006

The effect of A/B moi ratios and sintering temperatures on dielectric properties and microstructure of $(Ba_{0.93}Ca_{0.07})_m(Ti_{0.82}Zr_{0.18})O_3$ ceramics were investigated. The dielectric constant decreased with increasing the A/B mol ratio. However, the dielectric loss is improved. As the dielectric properties of A/B mol ratio with m = 1.009 at sintered temperature $1260^{\circ}C$, we obtained dielectric constant 12,800, dielectric loss $3.5\%$ and Y5V temperature characteristics. Highly reliable Ni-MLCCs, 1.6mm$(length){\time}0.8mm(width){\time}0.8mm$(height) with capacitance of 1.23 ${\mu}F$ and 야ssipation loss of $5.2\%$ were obtained employing dielectric material composed of $(Ba_{0.93}Ca_{0.07})_{1.009}(Ti_{0.82}Zr_{0.18})O_3$ - $MnO_2\;0.2wt\%-Y_2O_3\;0.18wt\%,\;-\;SO_2\;0.15wt\%-(Ba_{0.4}Ca_{0.6})SiO_3\;1wt\%$.

• Economic and Environmental Geology
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• v.43 no.3
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• pp.269-278
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• 2010

We investigated characteristics of the coloring material of Dancheong pigments and hope that this study contributes the revival of traditional Dancheong pigments color. For this purpose, we collected Dancheong fragment samples that fell off naturally from old wooden buildings in Gwangju and Jeonnam and analyzed the natural coloring material by XRD and EDS-SEM analysis method. In white pigments of Dancheong fragments, it is confirmed that gypsum$(CaSO_{4}{\cdot}2H_{2}O)$, quartz$(SiO_{2})$, white lead$(PbCO_{3})$ and calcite$(CaCO_{3})$ which have been used for white pigments since ancient times and $TiO_{2}$ which is common used in modern times. In red pigments of Dancheong fragments, it is confirmed that hematite$(Fe_{2}O_{3})$ and red lead$(Pb_{3}O_{4})$, which have been used for red pigments since ancient times and C.I. pigment orange $13(C_{32}H_{24}C_{12}N_{8}O_{2})$ but there is no cinnabar(HgS) which has been used since B.C. 3000 in China. In yellow pigments of Dancheong fragments, it is confirmed that crocoite$(PbCrO_{4})$ and massicot(PbO). In blue pigments of Dancheong fragments, it is confirmed that sodalite$(Na_{4}BeAlSi_{4}O_{12}Cl)$ and nosean $(Na_{8}Al_{6}Si_{6}O_{24}SO_{4})$ as coloring material of blue pigment and C.I. pigments blue $29(Na_{7}Al_{6}Si_{6}O_{24}S_{3})$ which is used in modern times. In green pigments of Dancheong fragments, it is confirmed that calumetite$(Cu(OHCI)_{2}{\cdot}2H_{2}O)$, escolaite(Cr2O3), dichromium trioxide$(Cr_{2}O_{3})$, emerald green$(C_{2}H_{3}As_{3}Cu_{2}O_{8})$, and C.I. pigments green$(C_{32}H_{16}-XCl_{x}Cu_{8})$ which is used in modern time. In black pigments of Dancheong fragments, Chiness ink(carbon black) is confirmed.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.3
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• pp.211-220
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• 2006

Need of porcelain-repair system is largely demanding as dental porcelain restorations are increased in clinical dentistry. This study investigated shear bond strength of commercial porcelain-repair systems on dental porcelain and their reliability. Experimental groups were as follows; Group A Super Bond C&B, Group B Porcelain repair kit, Group C Ceramic repair, and Group D Spectrum system as a control. Porcelain disks were fired and embedded in epoxy resin. Porcelain surface were ground using 220 grit SiC disk, then cleaned in ultrasonic bath. Then porcelain specimens were treated with each repair system. A clear polystyrene cylinder 3.5 mm in internal diameter was filled with composite resin. Then the resin cylinder was polymerized with a visible light curing unit. Thirty one specimens at each group were prepared and stored at $37^{\circ}C$ distilled water for 48 h. Specimens were tested in an Instron testing machine according to ISO TR 11405. Mean shear bond strength and standard deviation of each group was $15.7{\pm}4.1MPa$ (Group A), $12.8{\pm}4.9MPa$ (Group B), $7.2{\pm}3.0MPa$ (Group C) and $9.6{\pm}2.2MPa$ (Group D). ANOVA and Tukey HSD post-hoc test showed that there were significant differences between groups (p<0.05). Data of bond strength were analyzed with two-parameter Weibull distribution. Confidence interval of Weibull modulus (m-parameter) at 95% of Group A (3.5-6.3) and Group D (3.6-6.0) were significantly higher than Group B (2.2-3.7) and Group C (2.0-3.4). There was little correlation between mean shear bond strength and Weibull modulus. Results indicated that acid-etching of porcelain surface increased porcelain-resin shear bonding strength.

• Journal of fish pathology
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• v.26 no.2
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• pp.117-121
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• 2013

Three commercial exfoliating reagents, product A (main components: citric acid and vitamin C), B (herb) and C (nicotinamide), were used to study their exfoliation effect on abalone, Haliotis discus hannai from the substrate. The exfoliating reagents A, B, C and oxytetracycline (OTC, control) of 6-31.25 g/L and 12-37.5 g/L exfoliated 81.2-84.8% and 90.3-95% of abalone, respectively. Post-treatment recovery time for the abalone was similar for all the reagents except product C. Recovery period for the abalone immersed in OTC for 5-20 second was slightly shorter than the reagents A, B and C; however, no mortality was observed in any group except with the reagents B (concentration: 20 g/L, immersion time: 5 sec) and C (12 g/L, 10 and 20 sec) that showed negligible mortality of 3.3%. Higher concentration and longer treatment with the reagents resulted in longer recovery time of the detached abalone. Although abalone exposed to the reagents needs slightly longer time to recover than that to OTC, the exfoliation effect is much similar. These results indicate that the commercial exfoliating reagents can replace OTC to detach abalone, though they need to be cautiously handled.

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.653-663
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• 2010

Enantioselective total synthesis of (-)-clavosolide A and B was reported in full including the synthesis of proposed structure of (-)-clavosoldie A (1), revised structure of (-)-clavosoldie A (5), and revised structure of (-)-clavosoldie B (6). The relative and absolute stereochemistries of the natural products were confirmed unambiguously by comparing the optical rotation values and $^1H$ and $^{13}C$ NMR spectra of them.

• Oncology Letters
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• v.41 no.6
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• pp.3305-3312
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• 2019

Histone H2B monoubiquitination has been shown to play critical roles in diverse cellular processes including DNA damage response. Although recent data indicate that H2B monoubiquitination is strongly connected with tumor progression and regulation, the implications of this modification in lung adenocarcinoma are relatively unknown. In the present study, we demonstrated the clinical implication of H2B monoubiquitination and the potential role of tumor necrosis factor receptor-associated factor-interacting protein (TRAIP) in regulating its modification in lung adenocarcinoma. Immunohistochemical analysis showed that H2B monoubiquitination was significantly downregulated in 68 human lung adenocarcinoma patient samples compared to their normal adjacent tissues. Depletion of TRAIP by specific siRNA treatment markedly decreased ionizing radiation (IR)-induced H2B monoubiquitination. In addition, deletion mutants without RING domain or C-terminus of TRAIP diminished the ability to induce H2B monoubiquitination at lysine 120. Notably, the nuclear expression of TRAIP was positively related with H2B monoubiquitination levels in patients with lung adenocarcinoma. Furthermore, statistical analysis indicated that low levels of both TRAIP and H2B monoubiquitination, not each alone, in patients with lung adenocarcinoma were strongly correlated with poor survival. Taken together, these results suggest that TRAIP is a novel regulator of H2B monoubiquitination in DNA damage response and cancer development in lung adenocarcinoma.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.196-198
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• 2006

이 연구는 CBN을 건전한 브레이징을 하기 위해서, CBN과 금속필러메탈 접합계면에서의 금속성분과 산화물, 탄화물의 거동을 분석하는데 있다. 진공 인덕션 브레이징으로 온도는 $950{\sim}1100^{\circ}C$에서 브레이징 유지시간은 $5{\sim}30$분로 실시하였다. 금속필러로는 Ni-7Cr-3Fe-3B-4Si(wt.%)와 Ag-25Cu-5Ti(wt.%)을 사용하여 브레이징된 CBN은 $950{\sim}1000$도, 유지시간 10분 사이에서 각각 건전한 계면과 표면을 얻을 수 있었으며, 계면에서 Ti-rich상과 화합물이 확인되었다. 이상의 결과로 부터 화합물의 생성과 건전한 접합공정은 브레이징 온도와 시간이 좌우하며, N과 B, Ti의 함유량이 CBN의 브레이징 접합 특성의 중요변수로 생각되어진다. CBN과 Ni계/Ag계 브레이징 필러의 계면에서의 미세조직 및 화학반응의 메커니즘은 SEM, EPMA, XRD를 이용하여 분석하였다.

• Publications of The Korean Astronomical Society
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• v.5 no.1
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• pp.65-84
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• 1990

The temperature effects of the KNU UBV photometric system are investigated, using the HAMAMATSU 1P21 data. The variation of the passband width of V-band with temperature is about $5{\AA}/^{\circ}C$ while those of B-band and U-band are negligible. This large effect of V-band causes a significant variation of V-mag. and (B-V)-color with temperature such as ${\sim}0.02mag/^{\circ}C$ in both cases. This result strongly suggests that in the photometric observations of binary stars, the temperature effects of the response of photomultiplier and the passband of filters must be considered to avoid the systematic variation in magnitude and color particularly at the minimum of light curve.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.414-420
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• 1993

Escherichia coli mrdAts and mrdBts mutants forming spherical cells at 42C, were employed to investigate the possible role of both inner and outer membrance structures in the determination of cell shape of gram-negative cells. Spherical cells, but not rod-shaped wild types, were specifically killed by anionic detergents, such as sarkosyl, sodium dodecylsulfate and sodium deoxycholate. From the spherical intact cells grown overnight at 42C, much more proteins were released by sakosyl.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1314-1316
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• 1994

$0.36[wtx]Sio_2$ and $0.1[wtx]H_3BO_3$ were added to strontium ferrite magnets of the magnetoplumbite phase SrO $5.7Fe_2O_3$. This experiment was carried out to investigate the effects of particle size distribution as a function of milling time(20,30,40,50,60,70 hours) on the magnetic properties of SrO $5.7Fe_2O_3$ ferrite magnet. The B-H Curve, density and the degree of orientation were measured. The optimal conditions of making magnets and properties of a typical sample are the following : The milling time was 60 hours. Magnetic and physical properties are $B_r$=4000[G], $_BH_c$=3330[Oe], $_IH_c$=3525[Oe], (BH)max=3.786 [MGOe], density= $5.0063g/cm^2$, orientation factor f=0.813.