• Membrane Journal
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• v.26 no.2
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• pp.152-158
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• 2016

The Chlor-alkali (CA) membrane cell is a major electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. The CA membrane process has been attracted in the industries, since it has relatively low energy consumption when compared with other CA processes. The key component in CA process is perfluorinated sulfonic acid ionomer membranes, which provide ion-selectivity and barrier properties to produced gases. Unfortunately, there is limited information to determine which factors should be satisfied for CA applications. In this study, the influences of PFSA membranes on CA performances are disclosed. They include ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.183-188
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• 2007

Using BHK cells with stable expression of cardiac $Na^+/Ca^{2+}$ exchanger(BHK-NCX1), reverse mode(i.e. $Ca^{2+}$ influx mode) of NCX1 current was recorded by whole-cell patch clamp. Repeated stimulation of reverse NCX1 produced a cytosolic $Ca^{2+}$-dependent long-term inactivation of the exchanger activity. The degrees of inactivation correlated with NCX1 densities of the cells and were attenuated by reduced $Ca^{2+}$ influx via the reverse exchanger. The inactivation of NCX1 was attenuated by(i) inhibition of $Ca^{2+}$ influx with reduced extracellular $Ca^{2+}$, (ii) treatment with NCX1 blocker($Na^{2+}$), and (iii) increase of cytoplasmic $Ca^{2+}$ buffer(EGTA). In BHK-NCX1 cells transiently expressing TRPV1 channels, $Ca^{2+}$ influx elicited by capsaicin produced a marked inactivation of NCX1. We suggest that cytoplasmic $Ca^{2+}$ has a dual effect on NCX1 activities, and that allosteric $Ca^{2+}$ activation of NCX1 can be opposed by the $Ca^{2+}$-dependent long-term inactivation in intact cells.

• Progress in Superconductivity
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• v.5 no.1
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• pp.5-8
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• 2003

We studied the effect of spin injection on tunneling conduction properties of intrinsic Josephson junctions formed in $Bi_2$$Sr_2$$CaCu_2$$O_{ 8＋x}$ single crystals. properties of an identical stack (10${\times}$5.0${\times}$0.030 $\mu\textrm{m}^3$) of intrinsic Josephson junctions were compared for the bias current injected through Au and Co electrodes. The suppression of the superconducting gap in the $_2$ double layers and the interlayer Josephson critical current was manifested in the tunneling current-voltage characteristics of the stacks. This effect appears to be caused by the pair breaking associated with spin-polarized carriers injected from the Co electrode into the $Bi_2$$Sr_2$$_2$O$CaCu_{ 8＋x}$ single crystal. This study may provide valuable information on clarifying the mechanism of high- $T_{c}$ superconductivity.y.y.

• Journal of Electrochemical Science and Technology
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• v.14 no.4
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• pp.326-332
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• 2023

The high cost of Si-based solar cells remains a substantial challenge to their widespread adoption. To address this issue, it is essential to reduce the production cost of solar-grade Si, which is used as raw material. One approach to achieve this is Si electrodeposition in molten salts containing Si sources, such as SiO₂. In this study, we present the pulse electrodeposition of Si in molten CaCl₂ containing SiO₂ nanoparticles. Theoretically, SiO₂ nanoparticles with a diameter of less than 20 nm in molten CaCl₂ at 850℃ have a comparable diffusion coefficient with that of ions in aqueous solutions at room temperature. However, we observed a slower-than-expected diffusion of the SiO₂ nanoparticles, probably because of their tendency to aggregate in the molten CaCl₂. This led to the formation of a non-uniform Si film with low current efficiency during direct current electrodeposition. We overcome this issue using pulse electrodeposition, which enabled the facile supplementation of SiO₂ nanoparticles to the substrate. This approach produced a uniform and thick electrodeposited Si film. Our results demonstrate an efficient method for Si electrodeposition in molten CaCl₂ containing SiO₂ nanoparticles, which can contribute to a reduction in production cost of solar-grade Si.

• Development and Reproduction
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• v.15 no.1
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• pp.31-39
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• 2011

Change in intracellular $Ca^{2+}$-concentration ($[Ca^{2+}]_i$) is an essential event for egg activation and further development. $Ca^{2+}$ ion is originated from intracellular $Ca^{2+}$-store via inositol 1,4,5-triphosphate receptor and/or $Ca^{2+}$ influx via $Ca^{2+}$ channel. This study was performed to investigate whether changes in $Ca^{2+}$/calmodulin dependent protein kinase II (CaM KII) activity affect $Ca^{2+}$ influx during artificial egg activation with ethanol using $Ca^{2+}$ monitoring system and whole-cell patch clamp technique. Under $Ca^{2+}$ ion-omitted condition, $Ca^{2+}$-oscillation was stopped within 30 min post microinjection of porcine sperm factor, and ethanol-induced $Ca^{2+}$ increase was reduced. To investigate the role of CaM KII known as an integrator of $Ca^{2+}$- oscillation during mammalian egg fertilization, CaM KII activity was tested with a specific inhibitor KN-93. In the eggs treated with KN-93, ethanol failed to induce egg activation. In addition, KN-93 inhibited inward $Ca^{2+}$ current ($I_{Ca}$) in a time-dependent manner in whole-cell configuration. Immunostaining data showed that the voltage-dependent $Ca^{2+}$ channels were distributed along the plasma membrane of mouse egg and 2-cell embryo. From these results, we suggest that $Ca^{2+}$ influx during fertilization might be controlled by CaM KII activity.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.207-218
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• 1988

Effects of 1, 4-dihydropyridine compounds, such as nifedipine, nisoldipine, nitrendipine, and nimodipine which were calcium antagonists on the normal and Ca-dependent, slow channel mediated action potentials in the guinea pig's papillary muscle were investigated. The glass microelectrode was impaled into a papillary muscle cell for measurements of potential changes with the simultaneous tracing of isometric contraction. The concentration of Ca antagonists were 1 mg/l (nifedipine and nisoldipine), 2 mg/l (nitrendipine and nimodipine), which showed the maximal inhibition of isometric contraction (above 90%) and simultaneous effects on the normal action potentials and only the halves of those concentrations were sufficient to observe the effects on the calcium action potentials. The data for analysis were only chosen when the microelectrode was maintained in a cell throughout the experiments. 1, 4-Dihydropyridine compounds decreased the action potential duration but did not affect the resting membrane potential, overshoot, and upstroke velocity of the normal action potentials with the decrease in the isometric contraction. And with the decrease in the area and amplitude of isometric contraction, the area, amplitude, upstroke velocity and duration of Ca action potential was decreased. But the differences in the effects of the Ca antagonists were not observed. Therefore it is inferred that the changes in normal and Ca action potential induced by the 1, 4-dihydropyridine compounds with a common chemical structure would be caused by the slow inward Ca-current, not by a fast Na-current.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.298-305
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• 2014

In this study, a novel Randomly Shifted Certification Authority Authentication protocol was used in ad hoc networks to provide authentication by considering the MAC layer characteristics. The nodes achieve authentication through the use of public key certificates issued by a CA, which assures the certificate's ownership. As a part of providing key management, the active CA node transfers the image of the stored public keys to other idle CA nodes. Finally the current active CA randomly selects the ID of the available idle CA and shifts the CA ownership by transferring it. Revoking is done if any counterfeit or duplicate non CA node ID is found. Authentication and integrity is provided by preventing MAC control packets, and Enhanced Hash Message Authentication Code (EHMAC) can be used. Here EHMAC with various outputs is introduced in all control packets. When a node transmits a packet to a node with EHMAC, verification is conducted and the node replies with the transmitter address and EHMAC in the acknowledgement.

• Electronics and Telecommunications Trends
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• v.15 no.5 s.65
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• pp.73-85
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• 2000

인터넷 이용자와 트래픽의 급속한 증가는 인터넷의 이용에 많은 문제점들을 야기하고 있다. 각국은 차세대 인터넷에서의 기술 주도권 확보를 통하여 국가경쟁력을 강화하고 자국민의 삶의 질을 향상하고자 노력하고 있다. 미국의 NGI, Internet2, 캐나다의 CA*net이 대표적인 사례이다. 따라서 본 논문은 캐나다 정부가 주도적으로 전국 규모로 광 인터넷 네트워크 구축을 추진중에 있는 CA*net3에 대하여 추진 배경, 구축 및 운영 현황과 앞으로의 전개 방향을 살펴본다. 특히 CA*net3는 DWDM 기반의 코아 백본 네트워크와 CWDM과 기가 이더넷 기술에 기반을 두고 구축하고 있는 지역 네트워크(ORAN)로 이루어져 있다. 따라서 현재 추진중인 CA*net3 네트워크 구조에 대하여 중점적으로 살펴보며, 'Customer Empowered Networking Revolution'이라는 개념을 바탕으로 향후 추진하고자 하는 CA*net4 추진 동향에 대하여 자세히 살펴보고자 한다.

• Progress in Superconductivity
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• v.2 no.2
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• pp.65-70
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• 2001

$Pb/Bi_2Sr_2CaCu_2O_{8+\delta}$-single-crystal junctions with the tunneling direction along the c axis of the crystal were fabricated to obtain an s-wave-superconductor/d-wave-superconductor Josephson junctions. The tunneling R (T) curves and current-voltage characteristics show distinct features which can be explained only under the assumption that the order parameter of high-$T_c/Bi_2Sr_2CaCu_2O_{8+{\delta}}$ superconductors has a pure d-wave symmetry, which is in contrast to the case of $YBa_2Cu_3O_{7+{\delta$}}$erconductors where a minor s-wave component is also present..

• The Plant Pathology Journal
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• v.39 no.4
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• pp.374-383
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• 2023

Capsicum annuum (CA) is grown outdoors across fields in Jeollabuk-do, South Korea. The weeds surrounding these fields were investigated regarding the infection of 11 viruses infecting CA during the year 2014-2018. In the reverse transcription polymerase chain reaction diagnosis, 546 out of 821 CA samples (66.5%) were infected by nine viruses, and 190 out of 918 weed samples (20.7%) were infected by eight viruses. Correlation analysis of the mutual influence of the viruses infecting CA and weeds during these 5 years showed that five viruses had significant positive correlations with the infection in both CA and weeds. Over the study period, the weeds infected by cucumber mosaic virus (CMV) in the previous year were positively correlated with the incidence of CMV infection in CA in the current year, although the correlation was lower for tomato spotted wilt virus (TSWV) compared to CMV. The CMV infection percent was 14.0% in summer annuals, 11.4% in perennials, and 7.8% in winter annuals. However, considering the overwintering period without CA, the infection percent was 5.2% higher in winter annuals and perennials than that in summer annuals, indicating that winter annual and perennial weeds served as the main habitats for insect vectors. The TSWV infection percent in weeds was 10.4% in summer annuals, 6.4% in winter annuals, and 6.2% in perennials. The weeds surrounding CA fields, acting as the intermediate hosts, were found to be the potent sources of infection, influencing the spread and diversity of CA-infecting viruses. The results of this study can contribute to prevent viral infection in agricultural fields.