• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.16-18
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• 2002

We attempted to fabricate a dendrimer Langmuir-Blodgett(LB) films containing 48 pyridinepropanol functional end group. As the pyridinepropanol functional group could form a complex structure with metal ions. In this study the samples for electrical measurement were fabricated to two types metal complexes with $Pt^{4+}$ and $Fe^{2+}$ ions by LB method. And we have investigated the surface activity at the air-water interface as well as the electrical properties for the monolayers of pure G4-48PyP dendrimer and its complex with metal ions($Pt^{4+}$ and $Fe^{2+}$ ions). In the surface pressure-area($\pi-A$) isotherms of the dendrimers, the stable condensed films formed at the air-water interface and the metal ions effect showed the difference on molecular behavior. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage(I-V) characteristics of metal/dendrimer LB films/metal(MIM) structure. In conclusion, it is demonstrated that the metal ion around G4-48PyP dendrimer can contribute to make formation of network structure among dendrimers and it result from the change of electrical properties.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.573-579
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• 2004

Electroflotation, which is used as an alternative to sedimentation, is a separation treatment process that uses small bubbles to remove low-density particulates. Making allowances for recent collision efficiency diagram based on trajectory analysis, it is necessary to tailor zeta potential of bubbles that collide with negatively charged particles. In this paper, the study was performed to investigate the effects of magnesium and aluminium ions on zeta potential of bubbles. And, it was studied to find out factors which could affect the positively charged bubbles. Consequently, zeta potential of bubbles increased both with higher concentration of metal ions and in the acidic pH value. And, a probable principle that explained the procedure of charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and laying down of hydroxide precipitate. It also depended on the metal ion concentration in the solution to display its capacity to control the bubble surface.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.521-527
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• 1998

Removabilities of heavy metals(Cd and Pb) by the tea materials (barley-tea, corn-tea, jasmin-tea, brown rice-green tea, black-tea, cassia tora-tea, persimmon peel-tea, and rice-tea) in the tea-water were studied in the various conditions ; particle size of tea (20, 40, 70 mesh), concentration of heavy metal (25, 50, 100 ppm) and extraction temperature(20, 30, 50, 100$^{\circ}C$). The removabilities by the tea solids were increased as the particle size decreased, concentration of heavy metal increased, and extracting temperature increased. Of the nine kinds of tea, Cd and Pb removability by jasmin-tea was highest. In addition, heavy metal removability by cassia tora tea was better than that of other tea as extraction temperature was increased.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.76-79
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• 1983

The elution behaviors of a series of metal complexes, such as $Co(gly)_{3}$, $[Ni(en)_{3}]^{2+}$, $[Ni(phen)_3]^{2+}$, $[Fe(phen)_3]^{2+}$, $[Co(phen)_3]^3+$, $[Co(tn)_3]^3+$, $[Co(en)_3]^3+$ and $[Co(NH_3)_6]^3+$ (where gly; glycine, phen; phenanthroline, tn; trimethylenediamine, en; ethylenediamine), were studied in aqueous solution by measuring the retention volumes (v values) on SP-Sephadex C-25, cation exchange resin. It was found that the elution behaviors of metal complexes were apparently affected by salt concentrations, kinds of cations in eluent and kinds of anions in eluent, and according to the degrees of their effects coulombic forces, ion exchange capacities, the 'solvent effect' of resin backbone, hydrophobicity and hydrophilicity were applied to explain the elution mechanism.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.585-591
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• 1989

The effects of the charged metal on the overall electrostatic potential profiles and the capacitances of the electrical double layer are brought out. A model with a simplified jellium and a point-charged electrolyte is utilized in the present calculations. Electrons are assumed not to penetrate electrode surface due to a strong screening of electrolyte at the interface. Electron density functions and ion density functions are obtained, which are also based upon the Poisson equation and Boltzmann equation on either side of the interface. A complete potential profile starting from bulk electrode and ending at bulk electrolyte is obtained by connecting the two potential profiles (one inside the metal electrode, the other inside the electrolyte) with proper boundary conditions. In spite of the simplicity of the model, the present model reveals the importance of the effect of the charged metal on the electrostatic potential profile and the electrical double layer capacitances. The results are discussed and compared with the predictions by Gouy Chapman theory.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1484-1488
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• 2004

The thiocyanate-selective PVC membrane electrodes based on 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-porphyrinatomanganese(III) chloride [Mn(TMP)Cl] and 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinatomanganese(III) chloride $[Mn(Cl_8TPP)Cl]$ as ion carriers were investigated. The effect of ionophores, membrane compositions, plasticizers, and solution pHs on the response characteristics were studied. The Mn(TMP)Cl as an ionophore shows the best potentiometric sensitivity with a slope of -58.7 mV/decade and a detection limit of $log[SCN^-]$ = -6.90, and selectivity for thiocyanate over strong hydrophobic interfering anions such as ${ClO_4}^-$ and salicylate. The potentiometric response is affected by the electronic effect of the substituents and solution pHs. The presence of substituents with electron donating and more liphophilic characters around the ligated metal center produces an improved response toward $SCN^-$.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.369-374
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• 2021

Brown blotch disease of oyster mushrooms is caused by tolaasin and its analog peptide toxins which are produced by Pseudomonas tolaasii. Tolaasin peptides form pores in the plasma membrane and destroy the fruiting body structure of mushroom. Lysis of red blood cells, hemolysis, can be occurred by cytotoxic activity of tolaasin. The hemolytic activity of tolaasin is inhibited by metal ions, such as Zn²⁺ and Ni²⁺. When Gadolinium ion was added, a biphasic effect was observed on tolaasin-induced hemolysis, an increase in hemolysis at submillimolar concentrations and an inhibition at millimolar concentrations. The mechanism of gadolinium ion-induced inhibition of tolaasin activity may not be similar to those of the inhibitions by other metal ions. Since gadolinium ion has been reported to change a lateral pressure of lipid membrane by binding to the negative charges of membrane lipids, it may not directly work on the tolaasin channel gating, but rather decrease the stability of tolaasin channel by increasing firmness of membrane.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.2
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• pp.74-79
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• 2018

In this report, the results of a systematic study on the effects of polycrystalline silicon gate depletion on the reliability characteristics of metal-oxide semiconductor field-effect transistor (MOSFET) devices were discussed. The devices were fabricated using standard complimentary metal-oxide semiconductor (CMOS) processes, wherein phosphorus ion implantation with implant doses varying from $10^{13}$ to $5{\times}10^{15}cm^{-2}$ was performed to dope the polycrystalline silicon gate layer. For implant doses of $10^{14}/cm^2$ or less, the threshold voltage was increased with the formation of a depletion layer in the polycrystalline silicon gate layer. The gate-depletion effect was more pronounced for shorter channel lengths, like the narrow-width effect, which indicated that the gate-depletion effect could be used to solve the short-channel effect. In addition, the hot-carrier effects were significantly reduced for implant doses of $10^{14}/cm^2$ or less, which was attributed to the decreased gate current under the gate-depletion effects.

• Journal of the Korean Chemical Society
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• v.28 no.2
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• pp.86-94
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• 1984

The single crystal ion-selective electrode,$ {\beta}-Ag_3SI/PVC-THF $membrane electrode has showed a linear potential response to the activities of iodide ion (10-1${\sim}$10-7M). The $ {\beta}-Ag_3SI$ membrane electrode was compared with AgI/PVC-THF membrane and copper metal plate membrane electrodes. In order to measure the selectivity coefficient of the electrodes toward $Cl^-$ and $Br^-$, the separation and mixed solution method were employed. The potential-time curve was obtained by the usual immersion technique and pH effect was also examined. The orders of selectivity for $Br^-$, $Cl^-$ and stability of response time are ${\beta}-Ag_3SI/PVC-THF $membrane > AgI/PVC-THF membrane > copper metal plate membrane. These electrodes could be used as indicating electrodes in the potentiometric titration of a single halide and mixed halides with the standard solution of silver nitrate.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.282-284
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• 1991

The yeast, Hansenula anomala B-7, isolated from the $Cd^{2+}$ rich soils and determined to be tolerant in the high concentration of $Cd^{2+}$ were employed in this work. Its intact cells grown in high concentration of $Cd^{2+}$ were observed to be Iysed at the early stage when transferred to a cadmium deficient broth. Its intact cells found to be not Iysed and grow well under the high concentration of $Cd^{2+}$. The Iysis of the intact cells grown at the high concentration of $Cd^{2+}$ ion was not found when the metal ions were replaced with $Cd^{2+}$ ion in the same concentration. This result indicated that Iysis of yeast cells, at least in this isolate, would be related to cell osmosis with the mineral ions added.