• Title/Summary/Keyword: RuO$_2$

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Synthesis and Characterization of New Transition Metal Complexes of Schiff-base Derived from 2-Aminopyrimidine and 2,4-Dihydroxybenzaldehyde and Its Applications in Corrosion Inhibition (2-Aminopyrimidine 및 2,4-Dihydoxybenzaldehyde 치환체인 Schiff-염기의 전이금속 착물에 대한 합성 및 특성 그리고 부식방지에의 응용)

  • Ouf, Abd El-Fatah M.;Ali, Mayada S.;Soliman, Mamdouh S.;El-Defrawy, Ahmed M.;Mostafa, Sahar I.
    • Journal of the Korean Chemical Society
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    • v.54 no.4
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    • pp.402-410
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    • 2010
  • New complexes cis-[$Mo_2O_5(Hapdhba)_2$], trans-[$UO_2(Hapdhba)_2$], [Pd(Hapdhba)Cl($H_2O$)], [Pd(bpy)(Hapdhba)]Cl, [Ag(bpy)(Hapdhba)], [$Ru(Hapdhba)_2(H_2O)_2$], [$Rh(Hapdhba)_2Cl(H_2O)$] and [Au(Hapdhba)$Cl_2$] are reported, where $H_2$apdhba is the Schiff-base derived from 2-aminopyrimidine and 2,4-dihydroxy benzaldehyde. The complexes were characterized by IR, electronic, $^1H$ NMR and mass spectra, conductivity, magnetic and thermal measurements. The inhibitive effect of $H_2$apdhba for the corrosion of copper in 0.5 M HCl was also determined by potentiodynamic polarization measurements.

Effect of Thermal Treatment Temperature on Lifespan of Conductive Oxide Electrode

  • Yoo, Y.R.;Chang, H.Y.;Jang, S.G.;Nam, H.S.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.6 no.2
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    • pp.44-49
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    • 2007
  • Dimensionally stable anodes have been widely used to cathodically protect the metallic materials in corrosive environments including concrete structure as the insoluble anode. Lifespan of the anode for concrete construction can be determined by NACE TM0294-94 method. Lifespan of conductive oxide electrode would be affected by thermal treatment condition in the process of sol-gel coatings. This work aims to evaluate the effect of thermal treatment temperature on the lifespan of the $RuO_{2}$ electrode. $450^{\circ}C$ treated conductive oxide electrode showed the excellent properties and its lifespan was evaluated to be over 88 years in 3% NaCl, 4% NaOH, and simulated pore water. This behavior was related to the formation of $RuO_{2}$.

Microstructural Investigation of $Ba_{0.7}Sr_{0.3}TiO_3$ (BST) Thin Films on Various Electrodes and Buffers

  • Seokmin Hong;Rhim, Sung-Min;Heungjin Bak;Ilsin An;Kim, Ok-Kyung
    • The Korean Journal of Ceramics
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    • v.6 no.4
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    • pp.333-338
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    • 2000
  • $Ba_{0.7}Sr_{0.3}TiO_3$(BST) thin films were deposited simultaneously on various electrodes and buffers by the sputtering technique. When the substrate temperature was varied, the BST thin film on each electrode showed good crystallinity above $550^{\circ}C$ as revealed by X-ray diffraction measurements. The surface morphology, determined by atomic force microscopy, indicated that the roughness of BST thin films on $RuO_2$was substrate dependent. However, BST thin films on Ru electrodes are smoother and showed no substrate dependence, probably because the precursor surface diffusion length was greater than the sinusoidal perturbations of the wavelength.

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Isotopic Compositions of Ruthenium Predicted from Stellar Evolution Using the NuGrid Project

  • Kim, Seonho;Sung, Kwang Hyun;Kwak, Kyujin
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.46.2-46.2
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    • 2021
  • Presolar silicon carbide (SiC) grains form around in the envelopes of asymptotic giant branch (AGB) stars by satisfying C/O>1 which is an optimal condition for SiC grains to condense in the stellar outflows. Ruthenium (Ru) isotopes are locked into the SiC grains during the condensation of SiC grains. We investigate the isotopic compositions of Ru in the stellar winds by using the NuGrid data, which are obtained by nucleosynthesis calculations during the stellar evolution. We compare the isotopic compositions of Ru obtained from the NuGrid data with measurements and the predictions obtained from different codes. Our results present a piece of evidence that SiC grains in the presolar system came from low-mass and low-metallicity AGB stars, also confirming that they were not from massive stars. We also suggest a new scenario in which the total stellar yields are also considered because SiC grains can condense during the collapse of molecular clouds.

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Enhanced Electrogenerated Chemiluminescence of Tris (2,2'-bipyridyl) Ruthenium (II)-$S_2O_8^{2-}$ System by Sodium Dodecyl Sulfate

  • Kang, Sung-Chul;Oh, Soo-Il;Kim, Kang-Jin
    • Bulletin of the Korean Chemical Society
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    • v.11 no.6
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    • pp.505-508
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    • 1990
  • The electrochemical reduction and electrogenerated chemiluminescence (ECL) of $Ru(bpy)_3^{2+}-S_2O_8^{2-}\;in\;CH_3CN-H_2O$ solution were studied in the presence of sodium dodecyl sulfate (SDS) as an anionic surfactant. SDS enhanced the ECL and the fluorescence intensities and lengthened the duration of ECL due to the solubilization of reactants and possibly to the stabilization of ECL intermediates in the SDS micellar environment.

A Study on Direct Decomposition and Selective Catalytic Reduction of NO over Ru-HZSM-5 Catalyst in the Presence of Excess Oxygen (과잉 산소 존재 하에서 Ru-HZSM-5촉매를 사용한 NO 분해 반응 및 선택적 촉매 환원 반응에 관한 연구)

  • Bae, Jae Yong;Chung, Sang Chul;Lee, Wha Young
    • Applied Chemistry for Engineering
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    • v.9 no.3
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    • pp.355-360
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    • 1998
  • Reduction activity of precious metal-loaded HZSM-5 for NO has been studied and was compared to that of Cu-HZSM-5 in the presence of excess oxygen. It was found that among the catalysts used in this study, Ru-HZSM-5 was the most active catalyst for the reduction of NO to $N_2$ in the absence of hydrocarbon reductant. The highest conversion obtained was 45%. No severe inhibition of water vapor to the reduction was observed. It is suggested that the higher catalytic activity of Ru-HZSM-5 may result from the better ability to oxidize NO to $NO_2$ in the presence of excess oxygen. A proposed reaction mechanism for the reduction of NO to $N_2$ in the presence of excess oxygen is that NO is oxidized to $NO_2$ on the surface of Ru-HZSM-5 catalyst and the adsorbed $NO_2$ on the surface is then decomposed to $N_2$. $NO_2$ is supposed to the reaction.

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