• Title/Summary/Keyword: Metal Chloride

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Characterization of Fibrinolytic Proteases from Gloydius blomhoffii siniticus Venom

  • Choi, Suk-Ho
    • Journal of Pharmacopuncture
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    • v.14 no.3
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    • pp.71-79
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    • 2011
  • Objectives : This study was undertaken to identify fibrinolytic proteases from Gloydius blomhoffii siniticus venom and to characterize a major fibrinolytic protease purified from the venom. Methods : The venom was subjected to chromatography using columns of Q-Sepharose and Sephadex G-75. The molecular weights of fibrinolytic proteases showing fibrinolytic zone in fibrin plate assay were determined in SDS-PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis) The effects of inhibitors and metal ions on fibrinolytic protease and the proteolysis patterns of fibrinogen, gelatin, and bovine serum albumin were investigated. Results : 1) The fibrinolytic fractions of the three peaks isolated from Gloydius blomhoffii siniticus venom contained two polypeptides of 46 and 59 kDa and three polypeptides of 32, 18, and 15 kDa and a major polypeptide of 54 kDa, respectively. 2) The fibrinolytic activity of the purified protease of 54 kDA was inhibited by metal chelators, such as EDTA, EGTA, and 1,10-phenanthroline, and disulfhydryl-reducing compounds, such as dithiothreitol and cysteine. 3) Calcium chloride promoted the fibrinolytic activity of the protease, but mercuric chloride and cobalt(II) chloride inhibited it. 4) The fibrinolytic protease cleaved preferentially A${\alpha}$-chain and slowly B${\beta}$-chain of fibrinogen. It also hydrolyzed gelatin but not bovine serum albumin. Conclusions : The Gloydius blomhoffii siniticus venom contained more than three fibrinolytic proteases. The major fibrinolytic protease was a metalloprotease which hydrolyzed both fibrinogen and gelatin, but not bovine serum albumin.

Electrocatalytic Effects for the Reduction of Thionyl Chloride in $Li/SOCl_2$ Cell Containing Schiff Base Metal(II) Complexes

  • Kim, Woo-Seong;Chung, Kwang-Il;Kim, Shin-Kook;Jeon, Seung-Won;Kim, Yeon-Hee;Sung, Yung-Eun;Choi, Yong-Kook
    • Bulletin of the Korean Chemical Society
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    • v.21 no.6
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    • pp.571-576
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    • 2000
  • Electrocatalytic effects for the reduction of thionyl chloride in $LiAICI_4/SOCl_2$ electrolyte solution containing Schiff base M(II) (M; Co and Fe) complexes are evaluated by determining kinetic parameters with cyclic voltammetry and chronoamperometry at a glassy carbon electrode. The charge transfer process during the reduction of thionyl chloride is affected by the concentration of the catalyst. The catalytic effects are demonstrated from both a shift of the reduction potential for the thionyl chloride toward a more positive direction and an increase in peak currents. Catalytic effects are larger in thionyl chloride solutions containing the binuclear [M(II) $_2$ (TSBP)] complex rather than mononuclear [M(II)(BSDT)] complexes. Significant improvements in the cell performance have been noted in terms of both thermodynamics and activation energy for the thionyl chloride reduction. The activation energy calculated from the Arrhenius plots is 4.5-5.9 kcal/mole at bare glassy carbon electrodes. The activation energy calculated for the catalyst containing solution is 3.3-4.9 kcalmole, depending on whether the temperature is lowered or rasied.

Hydrogen Evolution Properties of Alanate-based Hydrogen Storage Materials (알라네이트 계 수소 저장 물질의 수소 방출 특성)

  • JEONG, HEONDO
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.4
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    • pp.361-368
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    • 2017
  • Alanate-based materials, which were known to have high hydrogen storage capacity, were synthesized by mechanochemically metathesis reaction of metal chloride and sodium alanate without solvent. XRD patterns of synthesized materials showed that metathesis reaction of cations between metal chloride and sodium alanate was progressed favorably without any solvent. Magnesium alanate showed that 3.2 wt.% of hydrogen was evolved by the thermal decomposition. The addition of a small amount of Ti to the magnesium alanate greatly reduced hydrogen evolution temperature. Also, Ti doped magnesium alanate had a good regeneration property. Both the calcium and lithium-magnesium alanate showed the lower starting temperature of the two step hydrogen evolution and fast kinetics for the hydrogen evolution.

Hydrogenation of Arenes with Metallic Iridium and Rhodium Powders Prepared from Iridium(Ⅰ) and Phodium(Ⅰ)-COD Complexes under Mild Conditions

  • 진종식;이병노;문지중;송중호;박용선
    • Bulletin of the Korean Chemical Society
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    • v.16 no.6
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    • pp.528-533
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    • 1995
  • Metallic iridium and rhodium powders prepared from the reactions of [M(COD)(PhCN)2]ClO4 (M=Ir(1), Rh(2); COD=1,5-cyclooctadiene) with hydrogen at room temperature in methylene chloride show catalytic activities for hydrogenation of arenes at room temperature under atmospheric pressure of hydrogen. Most substituents (CH3, COOH, NO2, CH2OH, CHO, OPh, OCH3, C=C, halogens and CH2Cl) on aromatic ring suppress the rate of the hydrogenation of the aromatic ring while the aromatic ring hydrogenation of phenol and 1,4-dihydroxobenzene is faster than that of benzene over these metallic powders. Hydrogenation of benzoic acid occurs only at the aromatic ring leaving the COOH group intact over iridium metal powders while benzoic acid is not hydrogenated at all over rhodium metal powders. Carbonyl, nitro, acetylenic and olefinic groups on an aromatic ring are hydrogenated prior to the aromatic ring hydrogenation. Hydrogenolysis of OH groups of phenol, benzyl alcohol and 1,4-dihydroxobenzene, and hydrodehalogenation of halobenzenes, benzyl halides and cinnamyl chloride also occur along with the hydrogenation of aromatic ring.

A Study on the Examination of Reaction Mechanism for Molten Salt Electrolysis of Titanium Dioxide (이산화타이타늄의 용융염 전기분해 반응기구 규명에 관한 연구)

  • Jo, Sung-Koo;Jung, Jae-Young
    • Korean Journal of Metals and Materials
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    • v.47 no.3
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    • pp.182-187
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    • 2009
  • The molten salt electrolysis is applied to reduce titanium dioxide to titanium metal using calcium chloride as an electrolyte and the reaction mechanism of the reduction process is examined by analyzing the reaction products. The process conditions to obtain titanium metal for $900^{\circ}C$ correspond to 2.9~3.2 V and 24 hours. The reaction products for 2.9 V at $900^{\circ}C$ include irregular-shaped titanium oxides such as $Ti_4O_7$, $Ti_3O_5$ and $Ti_2O_3$ and polyhedral $CaTiO_3$. Using these microstructure analysis, the sequential reaction mechanism for the electrochemical reduction of titanium dioxide to titanium is proposed.

A Study on Synthetic Method and Material Analysis of Calcium Ammine Chloride as Ammonia Transport Materials for Solid SCR (Solid SCR용 암모니아 저장물질인 Calcium Ammine Chloride의 합성방법 및 물질분석 연구)

  • Shin, Jong Kook;Yoon, Cheon Seog;Kim, Hongsuk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.2
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    • pp.199-207
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    • 2015
  • Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

SEPARATION BEHAVIOR OF WATER-ALCOHOL SOLUTION BY PARTIALLY DITHIOCARBAMATED POLY(VINYL CHLORIDE) MEMBRANE

  • Yamada, Sumio;Nakagawa, Tsutomu
    • Proceedings of the Membrane Society of Korea Conference
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    • 1993.10a
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    • pp.46-51
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    • 1993
  • Poly(vinyl chloride) was modified by reacting with sodium N-methyldithiocarbamate or N-methyl-N-carboxymethyldithiocarbamate to obtain crosslinked dithiocarbamated PVC(PMD, PSDC). In addition PSDC were substituted with metal ions of $Ma^+, Li^+$ and $Cs^+$. PLMD and PSDC were reacted with copper ions in alcohol or aqueous solution to produce chelate complexes of dithiocarbanated PVC, respectively(PMD-$Cu^{2+}$, PSDC-$Cu^{2+}$). PSDC was irradiated by ultraviolet light to enhance crosslinking(PSDC-UV).

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Study on the Effect of Iron-based Metal Catalysts on the Thermal Decomposition Behavior of ABS (Iron계 금속 촉매가 ABS의 열분해 거동에 미치는 영향에 관한 연구)

  • Jang, Junwon;Kim, Jin-Hwan;Bae, Jin-Young
    • Applied Chemistry for Engineering
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    • v.16 no.4
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    • pp.496-501
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    • 2005
  • The thermal degradation of ABS in the presence of iron-based metal catalysts has been studied by thermogravimetric analysis (TGA). The reaction of iron-based metal catalysts (ferric nitrate nonahydrate, ammonium ferric sulfate dodecahydrate, iron sulfate hydrate, ammonium ferric oxalate, iron(II) acetate, iron(II) acetylacetonate and ferric chloride) with ABS has been found to occur during the thermal degradation of ABS. In a nitrogen atmosphere, char formation was observed, and at $600^{\circ}C$ approximately 3~23 wt% of the reaction product was non-volatile char. The resulting enhancement of char formation in a nitrogen atmosphere has been primarily due to the catalytic crosslinking effect of iron-based metal catalysts. On the other hand, char formation of ABS in air at high temperature by iron-based metal catalyst was unsuccessful due to the oxidative degradation of the char.