The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform
Adesoji A. Adesina - One of the best experts on this subject based on the ideXlab platform.
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Syngas production from CH4 dry reforming over Co–Ni/Al2O3 catalyst: Coupled reaction-deactivation kinetic analysis and the effect of O2 co-feeding on H2:CO ratio
International Journal of Hydrogen Energy, 2012Co-Authors: Say Yei Foo, Chin Kui Cheng, Tuan-huy Nguyen, Adesoji A. AdesinaAbstract:Abstract The dry and oxidative dry reforming of CH 4 over alumina-supported Co–Ni catalysts were investigated over 72-h longevity experiments. The deactivation behaviour at low CO 2 :CH 4 ratio (≤2) suggests that carbon deposition proceeds via a Rapid dehydroPolymerisation step resulting in the blockage of active sites and loss in CO 2 consumption. In particular, at high temperatures of 923 K and 973 K, a ‘breakthrough’ point was observed in which deactivation that was previously slow suddenly accelerated, indicating Rapid Polymerisation of deposited carbon. Only with feed CO 2 :CH 4 > 2 or with O 2 co-feeding was coke-induced deactivation eliminated. In particular, O 2 co-feeding gave improved carbon removal, product H 2 :CO ratios more suitable for downstream GTL processing and stable catalytic performance. Conversion-time data were adequately fitted to the generalised Levenspiel reaction-deactivation model. Activation energy estimate (66–129 kJ mol −1 ) was dependent on the CO 2 :CH 4 ratio but representative of other hydrocarbon reforming reactions on Ni-based catalysts.
Paul Galvin - One of the best experts on this subject based on the ideXlab platform.
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A Rapid Polymerisation process realizing 3D biocompatible structures in a microfluidic channel suitable for genetic analysis
Sensors and Actuators B-chemical, 2009Co-Authors: Des Brennan, S. Dillmore, Eric Moore, Paul GalvinAbstract:Abstract Surface probe immobilisation is a complex and time consuming task undertaken prior to microfluidic integration, this requires surface functionalisation, biomolecule spotting, incubation and blocking steps. Traditional bonding techniques (anodic, thermal, etc.) or adhesives (UV cured) used to seal fluidic systems may denature biomolecules due to high temperature or vapour effects, thus bonding techniques such as thin film laminate or PDMS are used to seal systems, with substrate-fluidic alignment required prior to bonding. We propose a technique allowing probe DNA molecules to be immobilised in a sealed microfluidic system using (3D) hydrogel structures without any alignment steps. A prepolymer solution is introduced to the channels where photo-Polymerisation is undertaken forming 3D structures covalently attached to the channel surface. We use a photo-initiated prepolymer material poly-ethylene-glycol (PEG) to form structures containing probe DNA. This process is fast compared to conventional biomolecule immobilisation techniques and is also biocompatible, this direct write approach removes overnight immobilisation/incubation of the probe DNA, it also facilitates immobilisation within a sealed fluidic system where conventionally DNA probe spots must be immobilised prior to channel sealing. We consider the transport of target DNA from bulk analyte to the 3D gel structure and evaluate hybridisation within the microfluidic system.
G.b. Kunde - One of the best experts on this subject based on the ideXlab platform.
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Oxidative Stability of Biodiesel Using Tea Leaves
Asian Journal of Research in Chemistry, 2010Co-Authors: B. Sehgal, G.b. KundeAbstract:A comparative study of oxidation stability of biodiesel prepared via transesterification and sonication routes was carried out. The polyphenols from tea extract, while acting as an antioxidant could prolong the onset of degradation by about two weeks. Difference in viscosity and peroxide value were used as an indicator of oxidation. Though the polyphenols could not prevent a viscosity increase that corresponds to the beginning of Rapid Polymerisation but the rate of the increase was quiet slow. Polyphenols from tea extract stabilizes the methyl ester by reducing the rate of peroxide formation and by stabilising the viscosity. A sudden rise of viscosity was attributed to onset of secondary oxidation marked by an increased release of free fatty acid. The onset of secondary oxidation showed a marked delay in ultrasonicated samples as compared to transesterification.
Say Yei Foo - One of the best experts on this subject based on the ideXlab platform.
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Syngas production from CH4 dry reforming over Co–Ni/Al2O3 catalyst: Coupled reaction-deactivation kinetic analysis and the effect of O2 co-feeding on H2:CO ratio
International Journal of Hydrogen Energy, 2012Co-Authors: Say Yei Foo, Chin Kui Cheng, Tuan-huy Nguyen, Adesoji A. AdesinaAbstract:Abstract The dry and oxidative dry reforming of CH 4 over alumina-supported Co–Ni catalysts were investigated over 72-h longevity experiments. The deactivation behaviour at low CO 2 :CH 4 ratio (≤2) suggests that carbon deposition proceeds via a Rapid dehydroPolymerisation step resulting in the blockage of active sites and loss in CO 2 consumption. In particular, at high temperatures of 923 K and 973 K, a ‘breakthrough’ point was observed in which deactivation that was previously slow suddenly accelerated, indicating Rapid Polymerisation of deposited carbon. Only with feed CO 2 :CH 4 > 2 or with O 2 co-feeding was coke-induced deactivation eliminated. In particular, O 2 co-feeding gave improved carbon removal, product H 2 :CO ratios more suitable for downstream GTL processing and stable catalytic performance. Conversion-time data were adequately fitted to the generalised Levenspiel reaction-deactivation model. Activation energy estimate (66–129 kJ mol −1 ) was dependent on the CO 2 :CH 4 ratio but representative of other hydrocarbon reforming reactions on Ni-based catalysts.
Des Brennan - One of the best experts on this subject based on the ideXlab platform.
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A Rapid Polymerisation process realizing 3D biocompatible structures in a microfluidic channel suitable for genetic analysis
Sensors and Actuators B-chemical, 2009Co-Authors: Des Brennan, S. Dillmore, Eric Moore, Paul GalvinAbstract:Abstract Surface probe immobilisation is a complex and time consuming task undertaken prior to microfluidic integration, this requires surface functionalisation, biomolecule spotting, incubation and blocking steps. Traditional bonding techniques (anodic, thermal, etc.) or adhesives (UV cured) used to seal fluidic systems may denature biomolecules due to high temperature or vapour effects, thus bonding techniques such as thin film laminate or PDMS are used to seal systems, with substrate-fluidic alignment required prior to bonding. We propose a technique allowing probe DNA molecules to be immobilised in a sealed microfluidic system using (3D) hydrogel structures without any alignment steps. A prepolymer solution is introduced to the channels where photo-Polymerisation is undertaken forming 3D structures covalently attached to the channel surface. We use a photo-initiated prepolymer material poly-ethylene-glycol (PEG) to form structures containing probe DNA. This process is fast compared to conventional biomolecule immobilisation techniques and is also biocompatible, this direct write approach removes overnight immobilisation/incubation of the probe DNA, it also facilitates immobilisation within a sealed fluidic system where conventionally DNA probe spots must be immobilised prior to channel sealing. We consider the transport of target DNA from bulk analyte to the 3D gel structure and evaluate hybridisation within the microfluidic system.
