The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Sibudjing Kawi - One of the best experts on this subject based on the ideXlab platform.
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ni and or ni cu alloys supported over sio2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
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Ni and/or Ni–Cu alloys supported over SiO2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
Jangam Ashok - One of the best experts on this subject based on the ideXlab platform.
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ni and or ni cu alloys supported over sio2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
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Ni and/or Ni–Cu alloys supported over SiO2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
Yasotha Kathiraser - One of the best experts on this subject based on the ideXlab platform.
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ni and or ni cu alloys supported over sio2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
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Ni and/or Ni–Cu alloys supported over SiO2 catalysts synthesized via phyllosilicate structures for steam reforming of biomass tar reaction
Catalysis Science & Technology, 2015Co-Authors: Jangam Ashok, Yasotha Kathiraser, Sibudjing KawiAbstract:In this paper, we describe the synthesis of Ni/SiO2 and Ni–Cu/SiO2 catalysts derived from phyllosilicate structures (Ni/SiO2P and Ni–Cu/SiO2P, respectively) for steam reforming of biomass tar reaction. The steam reforming of biomass tar reaction was investigated with cellulose as a biomass model compound. The influence of steam-to-carbon ratio and reaction temperatures was also explored. Overall, the catalysts synthesized via phyllosilicate structures gave better catalytic performance than the catalysts prepared by the impregnation method. An optimum catalyst Composition of 30Ni–5Cu/SiO2P gave superior catalytic performance in terms of stability and activity compared to all other catalysts. At 600 °C, about 78% of biomass was converted to gaseous products over 30Ni–5Cu/SiO2P, which is the highest among all the catalysts tested. Temperature-programmed reduction results indicate that the metal–support interaction of Ni/SiO2P catalyst prepared via phyllosilicate structures is stronger due to the unique layered structure compared to that prepared by conventional impregnation (10Ni/SiO2). The formation of a unique layered structure in Ni/SiO2P and Ni–Cu/SiO2P was also confirmed through TEM analysis. The Surface Elemental Composition results obtained from XPS analysis show that the Cu/Ni Surface molar ratio for Ni–Cu/SiO2P catalysts is consistent with the actual molar ratio values obtained from SEM-EDX analysis. This result suggests that the bimetallic catalysts synthesized via the phyllosilicate structure route can yield uniformly distributed alloy species.
Kouichi Watanabe - One of the best experts on this subject based on the ideXlab platform.
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mechanical characteristics and Surface Elemental Composition of a yasargil titanium aneurysm clip after long term implantation
Journal of Neurosurgery, 2010Co-Authors: Yasunari Otawara, Kuniaki Ogasawara, Yoshitaka Kubo, Hiroshi Kashimura, Akira Ogawa, Kouichi WatanabeAbstract:The mechanical properties of titanium-alloy aneurysm clips after long-term implantation in the human cranium are unclear. The characteristics of a Yasargil titanium aneurysm clip were evaluated after long-term implantation for 12 years in a patient with a cerebral aneurysm. The closing forces of the retrieved clip before and after implantation were approximately equal. The bending test showed no differences between the retrieved and control clips. Titanium oxide and calcium were identified on the Surface of the retrieved clip, which indicated the formation of corrosion-resistant layers. Titanium-alloy clips retain their mechanical properties in the human cranium for a long time.
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Mechanical and Surface properties of Yasargil Phynox aneurysm clips after long-term implantation in a patient with cerebral aneurysm.
Neurosurgical Review, 2008Co-Authors: Yasunari Otawara, Kuniaki Ogasawara, Yoshitaka Kubo, Hiroshi Kashimura, Akira Ogawa, Kouichi WatanabeAbstract:This study evaluated the mechanical properties and the Surface Elemental Composition of Yasargil Phynox aneurysm clips implanted for 10 years in a patient with cerebral aneurysm. Two Yasargil Phynox aneurysm clips implanted 10 years previously to treat a ruptured vertebral artery aneurysm were retrieved when the regrown and ruptured aneurysm was repaired with a new aneurysm clip. Two new Yasargil aneurysm clips were used as controls. Measurements of closing force, bending strength, and the Elemental Composition of the clip Surface were performed. The closing force of the retrieved clips was similar or greater compared to the force before implantation. The bending test showed that the elastic limit and 0.2% proof load of the retrieved clip were higher than those of the unused clip, whereas the ultimate load of the retrieved clip was similar to that of the unused clip. The Elemental concentration of Cr oxide on the Surface of the retrieved clips was almost the same as that on the unused clips. The present study demonstrated that Yasargil Phynox aneurysm clips retain their mechanical properties and Surface Elemental Composition in vivo for a long time, which indicates that Yasargil aneurysm clips will remain reliable in patients for extended periods.
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Reliability of cobalt-chromium alloy aneurysm clips after long-term implantations in patients with cerebral aneurysms.
Journal of Neurosurgery, 2006Co-Authors: Yasunari Otawara, Kuniaki Ogasawara, Yoshitaka Kubo, Akira Ogawa, Miguel M. Endo, Kouichi WatanabeAbstract:Object. Aneurysm clip reliability after long-term implantation in vivo has not been examined. In this study the authors evaluated the mechanical properties and Surface Elemental Composition of Co-Cr alloy aneurysm clips implanted for more than 10 years in patients with cerebral aneurysms. Methods. Five aneurysm clips implanted for ruptured or unruptured intracranial aneurysms were retrieved and examined. New aneurysm clips were applied to the regrown aneurysms. The implantation period ranged from 11 to 20 years. Four new and unused aneurysm clips were also examined as controls. The mechanical properties of the clips were tested by measuring their closing force and bending strength. The Surface Elemental Composition of the aneurysm clips was evaluated using x-ray photoelectron spectroscopy. The closing force of the retrieved clips exceeded the minimum force requirement at the time of manufacture. The bending strength was similar between the retrieved and control clips. Chromium oxide was the predominant constituent on the Surface of all clips, and its concentration on the retrieved clips was higher than that on the control clips. Conclusions. Data in the present study demonstrated that Co-Cr alloy aneurysm clips retain their mechanical properties in vivo for a long time, which indicates the reliability of these clips.
L Nyborg - One of the best experts on this subject based on the ideXlab platform.
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on the Surface Elemental Composition of non corroded and corroded dental ceramic materials in vitro
Journal of Materials Science: Materials in Medicine, 2003Co-Authors: P Milleding, S Karlsson, L NyborgAbstract:Dental ceramics are traditionally looked upon as inert materials. As many are glass phased, it may be hypothesized that they will be subjected to glass corrosion in aqueous environments. The aim of the study was therefore to analyze the Surface Elemental Composition of glass-phased and all-crystalline ceramics, before and after low- and high-intensity, in vitro corrosion (milli-Q-water at 37±2 °C for 18 h and 4% acetic acid at 80±2 °C for 18 h, respectively). The analysis of the Surface Elemental Composition was performed using ESCA. The hypothesis was confirmed. After high-intensity corrosion, the complete wash out of alkali ions, alkaline-earth ions and Elemental alumina was found, leaving behind a Surface totally dominated by silica. The all-crystalline ceramics, densely sintered alumina and yttria-partially stabilized tetragonal zirconia, displayed only minor Surface changes, even after high-intensity corrosion. In comparison to the corrosion testing in acid, the corrosion process in milli-Q-water did not produce different results in principle, except for the lower magnitude of the depletion of alkali ions and the virtually unchanged level of Elemental alumina. Unexpectedly, no substantial difference in Surface degradation was found between the glass ceramic and the ordinary porcelain-fused-to-metal ceramic or between ceramics of higher sintering temperature and those of low or ultra-low sintering temperature. The Composition and microstructure alone did not appear to provide a full explanation for the inter-individual differences in Surface corrosion when exposed to comparable environmental conditions.
