• Membrane and Water Treatment
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• 제3권1호
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• pp.63-76
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• 2012

Mother liquid discharged from a salt-manufacturing plant was electrodialyzed at 25 and $40^{\circ}C$ in a continuous process integrated with $SO_4{^{2-}}$ ion low-permeable anion-exchange membranes to remove $Na_2SO_4$ and recover NaCl in the mother liquid. Performance of electrodialysis was evaluated by measuring ion concentration in a concentrated solution, permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions, current efficiency, cell voltage, energy consumption to obtain one ton of NaCl and membrane pair characteristics. The permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions was low enough particularly at $40^{\circ}C$ and $SO_4{^{2-}}$ transport across anion-exchange membranes was prevented successfully. Applying the overall mass transport equation, $Cl^-$ ion and $SO_4{^{2-}}$ ion transport across anion-exchange membranes is evaluated. $SO_4{^{2-}}$ ion transport number is decreased due to the decrease of electro-migration of $SO_4{^{2-}}$ ions across the anion-exchange membranes. $SO_4{^{2-}}$ ion concentration in desalting cells becomes higher than that in concentration cells and $SO_4{^{2-}}$ ion diffusion is accelerated across the anion-exchange membranes from desalting cells toward concentrating cells.

• 한국재료학회지
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• 제17권1호
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• pp.43-49
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• 2007

Electrochemical migration phenomenon is correlated with ionization of anode electrode, and ionization of anode metal has similar mechanism with corrosion phenomenon. In this work, in-situ water drop test and evaluation of corrosion characteristics for SnPb solder alloys in $Na_2SO_4$ solutions were carried out to understand the fundamental electrochemical migration characteristics and to correlate each other. It was revealed that electrochemical migration behavior of SnPb solder alloys was closely related to the corrosion characteristics, and Sn Ivas primarily ionized in ${SO_4}{^2-}$ solutions. The quality of passive film formed at film surface seems to be critical not only for corrosion resistance but also for electrochemical migration resistance of solder alloys.

• 한국항해항만학회지
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• 제34권10호
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• pp.787-792
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• 2010

콘크리트는 물시멘트비에 상응하는 공극을 가지게 되며, 공극을 통한 염소이온의 확산을 평가하기 위하여 해안가 폭로 및 해수 침지실험이 널리 사용된다. 이상의 실험은 경우에 따라서 다년간의 시간을 요하는 경우도 있어, 최근에는 전기 영동법에 기초한 급속 염소이온 확산시험을 실시하는 경우가 많으나, 그 값이 폭로 및 침지 시험에서 얻은 값과 상이한 경우가 많아 데이터의 실용성을 높이기 위하여 그 원인 규명이 절실한 실정이다. 본 연구에서는 평가 방법으로써 Nernst-Einstein의 식을 통한 염화물 이온 이동계수의 산정방법을 사용하였으며, NT BUILD 492법 및 해수 침지실험을 통한 확산 특성과 비교하여 값의 차이에 대하여 고찰하였다. 그 결과 실험인자의 변화가 염소이온 확산에 미치는 영향은 미비한 것으로 평가되어져 실험조건에서 발생하는 영향은 거의 없는 것으로 규명되었으며, NT BUILD 492법과도 거의 동일한 값이 구해졌다. 침지실험 결과와의 상이는 염소이온 확산에서 경계조건의 차이 및 염소이온의 시멘트 수화물과의 고정화에 의한 것으로 판단되어진다.

• Current Applied Physics
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• 제18권11호
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• pp.1431-1435
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• 2018

Using first-principles calculations, we successfully investigate the electrochemical performance of the monoclinic $NaMnO_2$ for the sodium ion batteries. $NaMnO_2$ possesses a voltage window of 3.54-2.52 V and theoretical reversible capacity of $136mAh\;g^{-1}$. Besides, we find that the metallicity of the monoclinic $NaMnO_2$ gradually increases during Na extraction. Moreover, the computational Na migration energy barrier in the monoclinic $NaMnO_2$ is 0.18 eV, ensuring ideal conductivity and reversible capacity. Although the Jahn-Teller distortion effects limit the enhancement of the reversible capacity of the monoclinic $NaMnO_2$, it is still a right cathode material for the sodium ion batteries. The computational results are well in consistent with the experimental investigations.

• 방사성폐기물학회지
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• 제8권3호
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• pp.201-205
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• 2010

고준위방사성폐기물에서 유출되어 나오는 아이오딘의 이동을 저지하기 위하여 은을 흡착시킨 벤토나이트 블록에 NaI 용액을 흘려주었을 때 대부분의 아이오딘이 흡착되었다. 이 은이온에 의한 아이오딘의 저지 메커니즘을 상세히 조사하기 위하여 아이오딘과 접촉하기 전후의 은이 흡착된 벤토나이트의 X-ray Absorption Near Edge Structure (XANES)와 Extended X-ray Absorption Fine Structure (EXAFS) 스펙트 럼과 표준물질로서 AgO, $Ag_2O$, AgI의 스펙트럼을 비교하였다. 그 결과, 벤토나이트에 흡착되었던 은이 떨어져 나와 AgI 침전 클러스터를 형성함으로서 아이오딘의 이동이 지연되는 것으로 생각된다.

• Corrosion Science and Technology
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• 제6권2호
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• pp.50-55
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• 2007

The smaller size and higher integration of advanced electronic package systems result in severe electrochemical reliability issues in microelectronic packaging due to higher electric field under high temperature and humidity conditions. Under these harsh conditions, electronic components respond to applied voltages by electrochemical ionization of metal and the formation of a filament, which leads to short-circuit failure of an electronic component, which is termed electrochemical migration. This work aims to evaluate electrochemical migration susceptibility of the pure Sn, Sn-3.5Ag, Sn-3.0Ag-0.5Cu solder alloys in $Na_{2}SO_{4}$. The water drop test was performed to understand the failure mechanism in a pad patterned solder alloy. The polarization test and anodic dissolution test were performed, and ionic species and concentration were analyzed. Ag and Cu additions increased the time to failure of Pb-free solder in 0.001 wt% $Na_{2}SO_{4}$ solution at room temperature and the dendrite was mainly composed of Sn regardless of the solders. In the case of SnAg solders, when Ag and Cu added to the solders, Ag and Cu improved the passivation behavior and pitting corrosion resistance and formed inert intermetallic compounds and thus the dissolution of Ag and Cu was suppressed; only Sn was dissolved. If ionic species is mainly Sn ion, dissolution content than cathodic deposition efficiency will affect the composition of the dendrite. Therefore, Ag and Cu additions improve the electrochemical migration resistance of SnAg and SnAgCu solders.

• 한국자기공명학회논문지
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• 제5권1호
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• pp.1-12
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• 2001

ZSM-5 gallosilicate molecular sieves was synthesized and cupric ion was ion-exchanged into the gallosilicate. The locations of Cu(ll) species in the framework and their interactions with various adsorbates were characterized by combined electron spin resonance(ESR) and electron spin echo modulation(ESEM) methods. It was found that in a fresh hydrated material, Cu(II) is octahedrally coordinated to six water molecules. This species is located in the channel intersections of two sinusoidal channels and rotates rapidly at room temperature. Evacuation removes some of these water molecules, leaving the Cu(II) coordinated to less water molecules and anchored to of oxygens in the channel wall. Dehydration produces two Cu(II) species, both of which are located in sites inaccessible to oxygen as evidenced by non-broadening of its ESR lines by oxygen. Adsorption of adsorbate molecules such as water, alcohols, ammonia, acetonitrile and ethylene on dehydrated CuNaH-ZSM-5 gallosilicate materials causes changes in the ESR spectrum of Cu(II), indicating the migration of Cu(II) into main channels to form complexes with these adsorbates there. Cu(II) forms a complex with two molecules of methanol, ethanol and propanol, respectively as evidenced by ESR parameters and ESEM data. Cu(II) also forms a square planar complex with four molecules of ammonia, based on the resolved nitrogen superhyperfine interactions and their ESEM parameters. Cu(II) forms a complex with two molecules of acetonitrile based on the ESR parameters and ESEM data. Interestingly, however, only part of Cu(II) interacts indirectly with one molecule of nonpolar ethylene based on ESR and ESEM analyses.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.338-338
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• 2011

The behavior of hydroxide ions on water-ice films was studied by using $Cs^+$ reactive ion scattering (RIS), low energy sputtering (LES) and temperature-programmed desorption (TPD). A $Cs^+$ beam of a low kinetic energy (<100 eV) from $Cs^+$ ion gun was scattered at the film surface, and then $Cs^+$ projectiles pick up the neutral molecules on the surface as $Cs^+$-molecule clusters form (RIS process). In LES process, the preexisting ions on the surface are desorbed by the $Cs^+$ beam impact. The water-ice films made of a thick (>50 BL) $H_2$O layer and a thin $D_2O$ overlayer were controlled in temperatures 90~140K. We prepared hydroxide ions by using Na atoms which proceeded hydrolysis reaction either on the ice film surface or at the interface of the $H_2O$ and $D_2O$ layers.[1] The migration of hydroxide ions from the $H_2O/D_2O$ interface to the top of the film was examined as afunction of time. From this experiment, we show that hydroxide ions tend to reside at the water-ice surface. We also investigated the H/D exchange reactions of $H_2O$ and $D_2O$ molecules mediated by hydroxide ions to reveal the mechanism of migration of hydroxide to the ice surface.

• The Korean Journal of Physiology and Pharmacology
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• 제27권4호
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• pp.311-323
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• 2023

Ion homeostasis, which is regulated by ion channels, is crucial for intracellular signaling. These channels are involved in diverse signaling pathways, including cell proliferation, migration, and intracellular calcium dynamics. Consequently, ion channel dysfunction can lead to various diseases. In addition, these channels are present in the plasma membrane and intracellular organelles. However, our understanding of the function of intracellular organellar ion channels is limited. Recent advancements in electrophysiological techniques have enabled us to record ion channels within intracellular organelles and thus learn more about their functions. Autophagy is a vital process of intracellular protein degradation that facilitates the breakdown of aged, unnecessary, and harmful proteins into their amino acid residues. Lysosomes, which were previously considered protein-degrading garbage boxes, are now recognized as crucial intracellular sensors that play significant roles in normal signaling and disease pathogenesis. Lysosomes participate in various processes, including digestion, recycling, exocytosis, calcium signaling, nutrient sensing, and wound repair, highlighting the importance of ion channels in these signaling pathways. This review focuses on different lysosomal ion channels, including those associated with diseases, and provides insights into their cellular functions. By summarizing the existing knowledge and literature, this review emphasizes the need for further research in this field. Ultimately, this study aims to provide novel perspectives on the regulation of lysosomal ion channels and the significance of ion-associated signaling in intracellular functions to develop innovative therapeutic targets for rare and lysosomal storage diseases.

• 마이크로전자및패키징학회지
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• 제26권3호
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• pp.75-80
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• 2019

친환경 및 고효율의 장점 때문에 신재생 에너지원으로 널리 사용되고 있는 실리콘 태양 전지는 모듈을 직렬 연결하여 발전할 때 500-1,500 V의 전압이 걸리게 된다. 모듈 프레임과 태양 전지 사이에 걸린 이러한 고전압 차에 의해 장시간 가동시 효율 및 최대 출력이 감소하는 현상인 potential-induced degradation(PID)은 실리콘 태양 전지의 수명을 단축시키는 주요 원인 중 하나로 알려져 있다. 특별히 전면 유리의 $Na^+$ 이온이 고전압에 의해 반사방지막을 거쳐 실리콘 내부로 확산하여 실리콘 내부 적층 결함 등에 축적되는 것이 PID의 원인으로 보고되고 있다. 본 연구에서는 p-형 PERC(passivated emitter and rear contact) 구조 실리콘 태양전지를 대상으로 $Na^+$ 이온의 확산 장벽으로 작용할 수 있는 $SiO_x$층이 p-n 접합과 반사방지막 사이에 삽입되었을 때 그 두께가 PID 현상 완화에 미치는 영향을 연구하였다. 96 시간 동안 1,000 V의 전압을 연속적으로 가한 후 병렬 저항, 효율 및 최대 출력을 측정한 결과 삽입된 $SiO_x$ 장벽층의 두께가 7-8 nm 이상일 때 비로소 PID 현상이 효과적으로 완화되는 것으로 나타났다.