• Membrane Journal
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• v.26 no.6
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• pp.432-448
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• 2016

In the last decade, various types of energy harvesting and conversion systems based on ion exchange membranes (IEMs) have been developed for eco-friendly power generation and energy-grid systems. In these membrane-based energy systems, high ion selectivity and conductivity properties of IEMs are critical parameters to improve efficiency of the systems such as proton exchange membrane fuel cells, anion exchange membrane fuel cells, redox flow batteries, water electrodialysis for hydrogen production, and reverse electrodialysis. This article suggests variable approaches to overcome trade-off limitation of polymeric membrane ion transport properties by reviewing various types of composite ion-exchange membranes including novel inorganic-organic nanocomposite membrane, surface modified membranes, cross-linked and pore-filled membranes.

• KSBB Journal
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• v.11 no.3
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• pp.360-366
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• 1996

Electrodialysis of acetic acid was studied to find out the trend of the transport of organic acids through ultrafiltration and ion exchange membranes. The net transport rate of acetic acid was determined from the electro-migration velocity relative to the electro-osmotic flow rate through the membrane. Electro-osmosis flows through ultrafiltration membranes were from the anodic side to the cathodic side in the presence of electric field. The surface of ultrafiltration membrane was measured by the electro-osmotic flow to be charged negatively. Different transport behaviors of acetic acid were found with the ultrafiltration membranes of different materials. In general, regenerated cellulose membranes (YM series) were more effective than polysulfone membranes (PM series) for the transport of acetic acid. The transport of acetic acid was affected by electric strength, distance between the electrodes, surface area of electrode, temperature, and pore size of membrane. The transport rate through the ion exchange membrane was 1.5 to 3 times of those through the ultrafiltration membranes at the constant current of 150 mA in the experimental ranges. The transport rate of acetic acid through the ion exchange membrane increased by 10% with a pulse electric field of 10 sec/hr.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.04a
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• pp.3-3
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• 1999

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.355-363
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• 1995

It has been well known that the intracellular calcium concentration $([Ca^{2+}]_i)$ in living cell is very sensitive to live or to survive, but the transmembrane system of calcium ion, especially mechanism of calcium ion movement in unexcitable state has been little elucidated. Though many proposed theories for calcium ion transport have been reported, it is still unclear that how could the sustained maintenance in cytosolic calcium level be done in cell. Since one of possible mechanisms of calcium transport may be related to the acetylcholine receptor-linked calcium channel, author performed experiment to elucidate this mechanism of calcium influx related to cholinergic receptor in ml muscarinic receptor-transfected RBL-2H3 cell-line. 1) The effects of carbachol both on calcium ion influx and on the secretion of hexosaminidase were respectively observed in the manner of time-related or concentration-dependent pattern in this model. 2) The effects of several metal cations on calcium transport were shown in carbachol-induced cell-line. 3) Atropine was administered to examine the relationship between cholinergic receptor and calcium ion influx in this model. 4) PMA (Phorbol 12-myristate 13-acetate) or PTx (Pertussis toxin) was respectively administered to examine the secondary mediator which involved pathway of calcium ion movement in carbachol-induced cell-line. The results of this experiments were as follows; 1) Carbachol significantly stimulated both the calcium influx and the secretion of hexosaminidase in the manner of the concentration-dependent pattern. 2) Atropine potently blocked the effects of carbachol in concentration-response manner. 3) Administered metal cations inhibited the calcium influx in carbachol-stimulated this model to the concentration-related pattern. 4) PMA did not inhibit carbachol-induced secretion of hexosaminidase, but blocked the calcium influx in this cell-line. 5) The suppression of carbachol-induced hexosaminidase secretion was shown in PTx-treated cell -line.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.129-135
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• 1994

Acyclic polyether dicarboxylic acid have been studied as metal cation carriers in a bulk liquid membrane system. The proton-ionizable ligands feature allows the coupling of a cation transport to reverse proton transport. This feature offers promise for the effective separation and concentration of metal cations with the metal cation transport being driven by a pH gradient. Metal cation transport increased regularly with increasing hydroxide($H^-$) concentration of source phase and with proton($H^+$) concentration of receiving phase. Competitive transport by the acyclic polyether dicarboxylic acids is selective for calcium ion over other alkaline-earth cations.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.79-89
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• 2017

Ion mobility mass spectrometry (IM-MS) combines the advantages of ion mobility spectrometry (IMS) and MS for effective gas-phase ion analysis. Separation of ions based on their mobilities prior to MS can be performed without a great loss in other analytical figures of merit, and the extra dimension of analysis offered by IM can be beneficial for isomer and complex sample analyses. In this review, basic principles of IMS and IM-MS are described in addition to an introduction to various IMS techniques and commercial IM-MS instruments. The nature of collision cross-section (${\Omega}_D$), an important parameter determining the transport properties of ions in IMS, is also explained in detail.

• Polymer(Korea)
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• v.27 no.4
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• pp.385-391
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• 2003

Lithium p-［Methoxyoligo(ethyleneoxy)］ benzenesulfonates (LiEOnBS) with different repeating unit of ethylene oxide were synthesized and were used for preparing gel-polymer electrolytes. The conductivities and lithium ion transference number were measured as a function of Li-salt concentration and repeating unit of ethylene oxide of the LiEOnBS. The maximum conductivity of the resulting gel-polymer electrolyte was found to be 4.89${\times}$10$\^$－4/ S/cm (LiEO7.3BS, 0.5 M) at 30$^{\circ}C$. The lithium ion transference number (t$\sub$Li$\sub$＋//) measurement were performed by means of the combination do polarization and ac impedance methods in gel-polymer electrolytes. Lithium ion transference number was measured to be in the range of 0.75∼0.92 for the LiEOnBS containing gel-polymer electrolytes. The maximum t$\sub$Li$\sub$＋// was obtained to be 0.92 for the 0.1 M LiEOnBS containing polymer electrolytes. The synthesized LiEOnBS showed single ion transport like characteristics when n was large than 3.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.88-96
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• 2000

The aim of the current study was to evaluate the transport system in EMT-6 cell for the uptake of the methylmercury(MeHg). Several inhibitors ere used to test used to test which potential transport system might be involoved in MeHg uptake. Probenecid was used to test the organic transport system, valinomycin for testing the effect of the membrane potential, cytochalasin B for testing the facilitated diffusive D-glucose transport system and colchicine for testing the microtubule system. Ouabain for evaluating active transport system, 4',4-diisothiocyano-2',2-stilbenedisulfonic acid(DIDS) the Cl- ion transport system and verapamil for the $Ca^{2+}$ transprot system. Significantly, MeHg decreased the synthesis of nitric oxcide(NO) and intracellular ATP in ENT-6 cells. In the condition of ouabain containing with MeHg decreased the production of NO and intracelluar ATP. In the treatment of inhibitors, ouabain showed protective effect against cytotoxicity of MeHg but ather inhibitors not showed protective effects. The protective effects of ouabain against the cytotoxicity of MeHg deoended on the concentration of added ouabain to the culture medium for MET-6 cells. These result showed that the uptake of MeHg might be involved in the active transport system. Active transports system seems to share similarities with the transport systems for the uptake of MeHg when using MeHg and MeHg-glutathione complex.x.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.61-72
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• 1993

Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsionsystem. First, one must effective extraction of the post transition metals, $Cd^{2+}$. $Pb^{2+}$ and $Hg^{2+}$ , into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several $A^-$ species such as $SCN^-$, $1^-$, $Br^-$ and $Cl^-$ is the order of the changing degree of solvation for $A^-$ and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of $Cd^{2+}$, $Pb^{2+}$, and $Hg^{2+}$ ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.416-422
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• 1993

In order to prepare high performance polymeric membrane, the crosslinked chitosan(C. Chitosan)membrane was prepared, the transport and the selective separation of the metal ions through the membrane were investigated. It was observed that the transport rates of the metal ions through the membrane increased according to the decreasing of the initial pH in downstream solution. Proton pump mechanism for this transport phenomenon was suggested. The transport selectivity is dependent on the selective adsorption resulting from the complex formation of chitosan with each metal ion. The separatin factor(${\alpha}_{Cu}{^{2+}}$) for the membrane was 9.5.