• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.04a
• /
• pp.318-322
• /
• 1997

The (Sr$_{l-x}$.Ca$_{x}$)TiO$_3$(0.05$\leq$x$\leq$0.2) ceramics were fabricated to form semiconducting ceramics by sintering at about 1350[$^{\circ}C$] in a reducing atmosphere($N_2$gas). After being fired in a reducing atmosphere, metal oxides, CuO, was painted on the both surface of the specimens to diffuse to the grain boundary. They were annealed at 1100[$^{\circ}C$] for 2 hours and cooled to room temperature. The grain boundary was composed of the continuous insulating layers. The capacitance changes slowly and almost linearly in the temperature region of -30~+85[$^{\circ}C$]. The capacitance characteristics appears a stable value within $\pm$10[%]. The conduction mechanism of the specimens observed in the temperature range of 25~125[$^{\circ}C$], and is divined into three regions haying different mechanism as the current increased: the region I below 230[V/cm] shows the ohmic conduction. The region II can be explained by the Poole-Frenkel emission theory, and the region III is dominated by the tunneling effect.ect.

• Proceedings of the Korean Biophysical Society Conference
• /
• 2003.06a
• /
• pp.53-53
• /
• 2003

Calumenin was previously identified as a high affinity Ca$\^$2+/ binding protein in mouse cardiac sarcoplasmic reticulum (SR). For the present study, a 48 kDa skeletal homologue of calumenin was identified by sucrose-density gradient of rabbit skeletal SR membranes, concanavalin A treatment, 2D-gel electrophoresis, $\^$45/Ca$\^$2+/ overlay, Stains-all staining, and MALDI-TOF analysis. We attempted to clone the skeletal calumenin by RT-PCR based on mouse cardiac and human calumenin sequences. The deduced amino acid sequence (315 residues) of the skeletal calumenin showed high identity to mouse cardiac calumenin (90％). As seen in the cardiac calumenin, the deduced sequence contains a 19 amino acid N-terminal signal sequence and a HDEF C-terminal sequence, a putative retrieval signal to ER. Also, the skeletal calumenin contains one N-glycosylation site, three PKC phosphorylation sites, eight casein kinase 2 phosphorylation sites, and 6 EF-hand domains. GST-calumenin showed a conformational change and increased mobility in the presence of Ca$\^$2+/ in SDS-PAGE. Three calumenin interacting proteins (ryanodine receptor 1, glycogen phosphorylase, and phosphofructo kinase) were identified by pull-down assay with GST-calumenin and solubilized SR. All the interactions were Ca$\^$2+/dependent. The present results suggest that calumenin plays an important role in Ca$\^$2+/ homeostasis of muscle cells.

• Electrical & Electronic Materials
• /
• v.10 no.6
• /
• pp.533-540
• /
• 1997

The microwave dielectric properties of ((P $b_{1-x}$ C $a_{x}$)Zr $O_3$ and (P $b_{0.63}$,C $a_{0.37-x}$ $M_{x}$)Zr $O_3$(M=Mg,Sr) ceramics were investigated. In (P $b_{1-x}$ C $a_{x}$)Zr $O_3$ (X=0.33~0.40) ceramics, high quality factor and small temperature coefficient of resonant frequency were obtain in (P $b_{0.63}$C $a_{0.37}$)Zr $O_3$with perovskite structure. In the case of (P $b_{0.63}$C $a_{0.37-x}$M $g_{x}$)Zr $O_3$ dielectric constant temperature coefficient of resonant frequency increased and quality factor decreased due to increase of polarization of A-O bonding. When replacing Ca ion with Sr ion with large ion radius, polarization decreased with increased of bonding length and thus dielectric constant and temperature coefficient of resonant frequency decreased.decreased.creased.

• Proceedings of the Korean Biophysical Society Conference
• /
• 1996.07a
• /
• pp.40-40
• /
• 1996

Abnormally high $Ca^{2+}$ concentrations have been reported in the cardiac myocytes of diabetic mellitus (DM). In order to elucidate the molecular mechanisms of the intracellular $Ca^{2+}$ overload, the activities of $^{45}$ Ca$^{2+}$ uptake and $^{45}$ Ca$^{2+}$ release were measured from the vesicles of junctional SR (Heavy SR, HSR). (omitted)omitted)

• Journal of the Microelectronics and Packaging Society
• /
• v.19 no.2
• /
• pp.41-45
• /
• 2012

Oxynitride green phosphors for white light emitting diodes (LEDs) were synthesized and their optical properties were evaluated. The N/O ratio ($\delta$) of $SrSi_2O_{2-{\delta}}N_{2+2/3{\delta}}:Eu^{2+}$ closely depended on the synthesizing conditions. The most excellent green emission (545 nm), which was assigned to the $5d{\rightarrow}4f$ transition of $Eu^{2+}$ ions, was achieved at the conditions of $1700^{\circ}C$, 5 mol% $Eu^{2+}$, and $H_2$ atmosphere. The well-developed $Ca-{\alpha}-SiAlON:Yb^{2+}$ particles with homogeneous size were obtained at m = 3 (n = 0.15) for the compound of $Ca_{0.5m-0.005}Yb_{0.005}Si_{12-(m+n)}Al_{m+n}O_nN_{16-n}$, resulting in the strong green emission at around 550 nm.

• Journal of information and communication convergence engineering
• /
• v.4 no.4
• /
• pp.158-161
• /
• 2006

[ $Bi_2Sr_2Ca_nCu_{n+1}O_y(n{\geq}0)$ ] thin film is fabricatedvia two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1549-1551
• /
• 2004

The Electromagnetic properties in BiPbSrCaCuO superconductor was studied. In the measurement of current-voltage characteristics, a voltage across the superconducting sample was observed on applying an external magnetic field. The voltage continues to appear the removal of the magnetic field. The appearance of the voltage is ascribed to the trapping of magnetic flux. Depanding on the direction of applied magnetic flux less than 2.5${\times}$10-5 T, the voltage in the magnetized sample increases or decreases. It is considered that mechanism of voltage occurrence can be explained by applying filament model.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.6
• /
• pp.535-538
• /
• 2002

Suspension effect has been studied by using superconductor of BiPbSrCaCuO ceramics containing $Ag_2()$. It has been clear that $Ag_2()$ acts as pinning center which plays an important role to the suspension effect. Magnetic repulsive force which affects a superconductor located in magnetic flux from toroidal magnet, has been investigated. It has been concluded that the suspension effect arises from the interaction between the pinning effect and the diamagnetic effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.04b
• /
• pp.88-91
• /
• 2000

The $(Sr_{0.85}Ca_{0.15})TiO_3$(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/$SiO_2$/Si) using RF sputtering method. The crystallinity of SCT thin films is increased with increase of substrate temperature in the temperature range of 200~500$[^{\circ}C]$. V-I characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature. The conduction mechanism of the SCT thin films observed in the temperature range of 25~100$[^{\circ}C]$ can be divided into four characteristic regions with different mechanism by the increasing current.

• Journal of the Korean Ceramic Society
• /
• v.38 no.4
• /
• pp.360-364
• /
• 2001

고상반응법(solid-state reaction)으로 산화물 초전도체 Bi$_{2+x}$ Sr$_{1.8}$ $CaCu_2$$O_{8+\delta}$(-0.2$\leq$x$\leq$0.2)을 제조하여 조성변화에 따른 산소량과 Bi 이온의 하전가(valence)가 구조변조의 주기에 미치는 영향을 조사하였다. 2212상의 단일상 고용한계는 -0.1$\leq$x$\leq$0.1 영역이었다. 이 영역에서 x의 증가에 따라 격자상수 c는 감소를 보이며, 온셋 임계온도 Tc$^{on}$ 과 산소량은 증가하는 경향을 보였다. 또한, Bi 이온의 하전기와 구조변조의 주기는 단일상 고용한계 영역 내에서 x의 증가에 따라 감소하는 경향을 보이고 있다. 구조변조의 주기는 산소량이 증가함에 따라 감소하고 Bi 이온의 하전가 증가에 따라 증가함을 보였다. 즉, 산소의 절대량과 Bi 이온의 하전가에 따라 구조변조의 주기가 변화하는 것을 알 수 있었다.