• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1765-1775
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• 2000

The removal of radioactive organic iodide generated from high temperature process in nuclear facility was generally performed by silver ion-exchanged synthetic zeolite (AgX). The purpose of this study is to obtain fundamental data for the substitution of natural zeolite(NZ) in stead of synthetic zeolite as supporter for the removal of methyl iodide in high temperature conditions. Therefore, NZ was modified with NaCl, $NaNO_3$ solution, and the analysis of the physical or surface characteristics through XRD, SEM-EDAX, and BET analysis was performed. In order to obtain the optimal surface-modification condition of NZ, adsorption capacities at $150^{\circ}C$ on surface-modified silver ion-exchanged NZ prepared with the variation of solution concentration were evaluated. The optimal condition of surface modification is that concentration of $NaNO_3$ and $AgNO_3$ are 1N and 1.2N, respectively(namely Ag-SMNZ). The adsorption isotherm of methyl iodide on Ag-SMNZ in a range of $100^{\circ}C$ to $300^{\circ}C$ was obtained, which is similar to that of 13X, and the maximum adsorption amount of Ag-SMNZ reached approximately 50% that of AgX. It would be evaluated that the adsorption capacity at $150{\sim}200^{\circ}C$ is relatively higher than other temperature, and the chemisorption between silver and iodide is attributed to a strong binding even after desorption test.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.280-289
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• 1998

Voltage-sensitive ion channels contribute to establishment of the cell excitablity and the generation of the cellular function. At hamster oocytes in the primitive stage during developing process, an inward current elicited by voltage pulses was found to be carried mainly by $Ca^{2+}$. Even at present, $Ca^{2+}$ channels serve as the most probable route to pass this inward current but there is no evidence of the presence of this channels in eggs. To date, both the characteristic properties and the physiological role in the early stage of development remain unclear. Here we examined the characteristic properties of the inward current and changes in this currents at unfertilized oocytes, fertilized zygotes and two-cell embryos using whole-cell voltage clamp technique. The inward current carried reportedly by $Ca^{2+}$ was remained following removing external $Ca^{2+}$ but completely abolished by further replacement of impermeants such as tetramethylammonium ion ($TMA^+$) or $choline^+$ instead of $[Na^+]_0$. Tetrodotoxin did not affect on this inward current remained at $[Ca^{2+}]_0$-free condition. Removal of $Na^+$ ion out of the experimental solution clearly decreased the current. After adding 2mM $Ca^{2+}$ to the $Na^+$-free media, the inward current was restored. Interestingly, this current carried by either $Ca^{2+}$ or $Na^+$ was decreased by the reduction of intracellular $Cl^-$ concentration, or by $Cl^-$ channel blockers such as niflumic acid, DIDS and SITS. When $Cl^-$ concentration was lowered without changes in other ionic components, this inward current was reduced. At fertilized oocytes and two-cell embryos, the inward current carried by $Ca^{2+}$ and $Na^+$ was severely reduced. Also $Cl^-$ component could not be observed. From these results, the inward current is composed of $Ca^{2+}$, $Na^+$ and $Cl^-$ component, suggesting that the channel carrying this inward current is not selective specifically to $Ca^{2+}$. During early stage of development, the voltage-sensitive ion current seems not to contribute essentially to the cell cleavage and differentiation. The loss of $Cl^-$ component after fertilization suggests that $Cl^-$ may play a role in maintaining the viability of unfertilized ova.

• Journal of Environmental Science International
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• v.5 no.2
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• pp.141-152
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• 1996

This study is an attempt to investigate the chemical components of precipitation and its variation according to surface wind. Precipitation samples were collected by an wet-only precipitation sampler during the period of October 1994 to September 1995 at Kyungsan in Korea. The results obtained in t체s study are summerized as follows. The annual average of precipitation pH is 5.0, the highest month of pH is July of 5.5, and the lowest month of pH is December of 4.4. The most frequent appearance is in the range of pH 5.0 to 5.5 and its rate is 56.8%, The order of ion concentration In precipitation is SO42->NO3->Cl- in case of anion and $Ca^{2+}$>$NH_4^{+}$>$Na^+$>$Mg^{2+}$ in case of cation. It is found from our analysis that the correlation coefficient among the precipitation pH and ion components is below r=0.3, while the correlation coefficient between $SO_4^{2-}$ and NO_3^{-}$, $Na^+$ and $Cl^+$ is above r=0.8, respectively. The mean pH of precipitation is 4.8 under the westerly wind and 5.2 under the easterly wind. The concentrations of anion and cation under the westerly wind are more than the concentrations under the easterly wind. In autumn, the concentration of Na+ and $Cl^+$ under the easterly wind are higher than the concentration under the westerly wind. The correlation coefficients between wind speed and pH, ion components show very low correlation of -0.41 r 0.2. But the present study show that the correlation coefficient between wind speed and pH of precipitation is positive and the correlation coefficients between wind speed and ion concentration is negative.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.46-54
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• 2002

A dielectric pellets bedded parallel plates with a membrane centered have been proposed as an ion separation and collection system in water. and effects of the relative dielectric constant and the applied square wave pulse voltage on the characteristics of ion separation and collection in tap water and NaCl dissolved tap water have been investigated. As a result, electrolyzed water of pH 3.1 and 10.6 were obtained with only tap water at the pulse current of 1.0[A] and flow rate of 0.5[LPM]. And the higher ionized water of pH 2.8 and pH 11.7 ware obtained in 0.1[%wt] NaCl dissolved water. When the dielectric pellets of BaTiO$_3$ having the highest dielectric constant were bedded in the ion separation and collection cell, the ionized water of pH 2.7 and pH 11.7 were obtained with only tap water. And the ionized water of pH 2.4 and pH 12.0 were obtained in 0.1[wt%] NaCl dissolved tap water with the dielectrics pellets bedded ones.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.178-182
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• 1983

The conductances of sodium, potassium, ammonium, tetramethylammonium, and tetraethylammonium iodides, picrates(Pic) of sodium and potassium, and tetrabutylammonium tetraphenyl-boride have been measured in ethylene carbonate-acetone mixtures at $25{\circ}C$. The limiting equivalent conductances of the electolytes were computed by Fuoss-Kraus equation and the order was $(C_4H_9)_4NB(ph)_4 at any composition of the mixtures. The dissociation constants of the salts showed that the mixtures are good ionizing solvents for the salts. The order of limiting ionic equivalent conductance, $Na^+, is consistent with exactly the reverse order found for solvation number. Effective solvated radii calibrated by the Nightingale method showed that picrate ion seems to be unsolvated and that iodide ion seems to be solvated to some extent in the mixtures.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.96-99
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• 2014

We fabricated $(Li_{0.5-x}Na_xLa_{0.5})Ti_{0.8}Zr_{0.2}O_3$(LNTLZ)ceramics ($0{\leq}x{\leq}0.4$) with a perovskite structure via standard solid state synthesis. The influence of Na content on the structural and electrical properties of LNTLZ ceramics was also investigated. During XRD patterns analysis, all of the samples showed orthorhombic structure. The resistance of LNTLZ ceramics decreased as Na content increased, and the maximum activation energy shows 0.56 eV at x=0.4 at room temperature. These results indicated that LNTLZ ceramics are a candidate for use Lithium ion batteries as electrolytes.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1607-1615
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• 2011

The adsorption performance of cupper and zinc ions($Cu^{2+}$ and $Zn^{2+}$) in aqueous solution was investigated by an adsorption process on reagent grade Na-A zeolite(Z-WK) and Na-A zeolite (Z-C1) prepared from coal fly ash. Z-C1 was synthesized by a fusion method with coal fly ash from a thermal power plant. Batch adsorption experiment with Z-C1 was employed to study the kinetics and equilibrium parameters such as initial metal ions concentration and adsorption time of the solution on the adsorption process. Adsorption rate of metal ions occurred rapidly and adsorption equilibrium reached at less than 120 minutes. The kinetics data of $Cu^{2+}$ and $Zn^{2+}$ ions were well fitted by a pseudo-second-order kinetics model more than a pseudo-first-order kinetics model. The equilibrium data were well fitted by a Langmuir model and this result showed $Cu^{2+}$ and $Zn^{2+}$ adsorption on Z-C1 would be occupied by a monolayer adsorption. The maximum adsorption capacity($q_{max}$) by the Langmuir model was determined as $Cu^{2+}$ 99.8 mg/g and $Zn^{2+}$ 108.3 mg/g, respectively. It appeared that the synthetic zeolite, Z-C1, has potential application as absorbents in metal ion recovery and mining wastewater.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.587-587
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• 2012

Supercapacitors, which can deliver significant energy with high power density, have attracted a lot of attention due to their potential application in energy storage. Among various oxide materials, sodium vanadate has been recognized as one of the most promising electrode materials because of high electrical conductivity. In addition, larger layer spacing of ${\beta}$-Na0.33V2O5 compared to V2O5 makes easier Li+ insertion. Moreover, ${\beta}$-Na0.33V2O5 has a tunnel like structure along b axis with 3 kinds of V site allowing it to enhance the ion intercalation by introducing three different intercalation sites along the tunnel. The tunnel can act as a fast diffusion path for ion diffusion, which can improve the overall charge storage kinetics. In this study, high quality single crystalline sodium vanadate (${\beta}$-Na0.33V2O5) nanowires were grown directly on Pt coated $SiO_2$ substrate by a facile chemical solution deposition method without employing catalyst, surfactant or carrier gas. The results show that great enhancement in capacitance was observed compared with previous reports.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.39-44
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• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.7-13
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• 2006

infrared(IR) absorption spectra were calculated for the ethyl ester of p-tert-butylcalix[4]arene (1) in the cone conformer and its alkali-metal-ion complex. The vibrational spectra were obtained by restricted Hartree-Fock (RHF) calculations with the 6-31G basis set. The characteristic vibrational frequencies of various C-O and C=O stretching motions of the complexes show that the structure of 1+K+ complex is almost of C4v symmetry compared to 1+Na+ (C2v) analogue. The theoretical results for the host molecule 1 and complex (1+Na+) were compared with the experimental results, and the calculated vibrational frequencies agree well with the features of the experimental spectra.