• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.191-191
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• 2005

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1045-1049
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• 1994

A simple and fast ion chromatographic method is developed for the determination of transition metals such as Fe, Cu, Ni, Zn and Co in atmospheric particulates. The method involves acid digestion, on-column preconcentration, and subsequent ion chromatogaphic detection. The precision of the method is less than 3${\%}$ RSD at parts per billion level for the metals studied. No significant interferences are observed. The results obtained with this method agree well with those by ICP-AES.

• Clean Technology
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• v.20 no.3
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• pp.269-276
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• 2014

This study was aimed to develop catalytic system for the dry-based reduction of oxidized mercury ($Hg^{2+}$) to elemental mercury ($Hg^0$) which is one of the most important components comprising mercury continuous emission monitoring system (Hg-CEMS). Based on the standard potential in oxidation-reduction reaction, transition metals including Fe, Cu, Ni and Co were selected as possible candidates for catalyst proceeding spontaneous reduction of $Hg^{2+}$ into $Hg^0$. These transition metal catalysts revealed high activity for reduction of $Hg^{2+}$ into $Hg^0$ in the absence of oxygen in reactant gases. However, their activities were greatly decreased in the presence of oxygen, which was attributed to the transformation of transition metals by oxygen to the corresponding transition metal oxides with less catalytic activity for the reduction of oxidized mercury. Hydrogen supplied to the reactant gases significantly enhanced $Hg^{2+}$ reduction activity even in the presence of oxygen. It might be due to occurrence of combustion reaction between $H_2$ and $O_2$ causing the consumption of $O_2$ at such high reaction temperature at which oxidized mercury reduction reaction took place. Because the system showed high activity for $Hg^{2+}$ reduction to $Hg^0$, which was compatible to that of wet-chemistry technology using $SnCl_2$ solution, the catalytic reduction system of Fe catalyst with the supply of $H_2$ could be employed as a commercial system for the reduction of oxidized mercury to elemental mercury.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.51.2-51.2
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.41-41
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.275.2-275.2
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• 2008

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2028-2030
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• 2005

The electrical conductivity of manganese oxide and complex manganese oxide produced by anodic deposition method was measured. The additive transition metal is Cu, Co and Fe. The transition metals like as Cu, Co and Fe improved electrical conductivity of complex manganese oxide compared with manganese oxide. This is coincide with the results of molecular orbital calculation by DV-Xa.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.397-401
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• 2009

The complexes of $C_2-\;and\;C_6$-dihydroceramides with transition metal ions have been investigated by using Electrospray ionization-tandem mass spectrometry (ESI-MS/MS). The formation and fragmentation pathways of several doubly charged cluster ions as well as singly charged cluster ions of $C_2-\;and\;C_6$-dihydroceramides with transition metal ions have studied by ESI-MS/MS in the positive mode. Under ESI conditions, dihydroceramides form singly and doubly charged complexes with transition metal ions $(Mn^{2+},\;Fe^{2+},\;Co^{2+},\;Ni^{2+},\;and\;Zn^{2+}\;except\;Cu^{2+})$ with the compositions of $[DHCer+M+2H^2O-H]^+,\;[2DHCer+M+2H2O-H]^+,\;[3DHCer+M+2H2O-H]^+,\;[2DHCer+M]^{2+},\;[3DHCer+M]^{2+},\;[4DHCer+M]^{2+},\;[5DHCer+M]^{2+},\;and\;[6DHCer+M]^{2+}\;(DHCer\;=\;C_2-\;or\;C_6$-dihydroceramide, M = transition metal ion). The different complexation behavior of copper is responsible for relatively lower affinity of dihydroceramides to copper compared to those of other transition metals. It is also found that in the mass spectrum of the dihydroceramide complexes with copper(II), [2DHCer+Cu-H]$^+$ was observed with considerable intensity as well as [2DHCer+Cu+2$H_2O-H]^+$ due to its different geometry from those of other metals.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.959-964
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• 2004

A low-dimensional metal frequently exhibits a metal-insulator transition through a charge-density-wave (CDW) or a spin-density-wave (SDW) which accompany it's structural changes. The transition temperature is thought to be determined by the amount of energy produced during the transition process and the softness of the original structure. $AMo_4O_6$ (A=K, Sn) are known to be quasi-one dimensional metals which exhibit metalinsulator transitions. The difference of the transition temperatures between $KMo_4O_6$ and $SnMo_4O_6$ (A=K, Sn) is examined by investigating their electronic and structural properties. Fermi surface nesting area and the lattice softness are the governing factors to determine the metal-insulator transition temperature in $AMo_4O_6$ compounds.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.176-183
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• 2020

In this study, synthesis of a hydrogel consisted of a coordination bond network between small organic molecules and transition metals had been carried out. By adding a tackifying material to the gel, the potential of the gel to be used as an adhesive material had been also confirmed. Synthesis of the adhesive had been done with simple mixing of 3 components: tannic acid, transition metal, and polymer. The tannic acid molecule possesses multiple hydroxyl groups that can form coordination bonds with the transition metals and hydrogen bonds with the hydrophilic polymers. Due to the morphology of the metal-organic complex and polymer dispersed in water, the fabricated material exhibited high adhesiveness and cohesiveness. Optimizing the rheological property had been conducted for use in adhesive by the synthesis with varying the transition metal (Fe³⁺, Ti⁴⁺), polymer, and treatment conditions. Rheological measurement results demonstrate the promising potential of the material as a bio-compatible and versatile pressure-sensitive adhesive with both high adhesiveness and cohesiveness.