The Experts below are selected from a list of 170391 Experts worldwide ranked by ideXlab platform
Marcel A. J. Somers - One of the best experts on this subject based on the ideXlab platform.
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Kinetics Analysis of two-stage austenitization in supermartensitic stainless steel
Materials & Design, 2017Co-Authors: Frank Niessen, Matteo Villa, John Hald, Marcel A. J. SomersAbstract:Abstract The martensite-to-austenite transformation in X4CrNiMo16-5-1 supermartensitic stainless steel was followed in-situ during isochronal heating at 2, 6 and 18 K min− 1 applying energy-dispersive synchrotron X-ray diffraction at the BESSY II facility. Austenitization occurred in two stages, separated by a temperature region in which the transformation was strongly decelerated. The region of limited transformation was more concise and occurred at higher austenite phase fractions and temperatures for higher heating rates. The two-step Kinetics was reproduced by Kinetics modeling in DICTRA. The model indicates that the austenitization Kinetics is governed by Ni-diffusion and that slow transformation Kinetics separating the two stages is caused by soft impingement in the martensite phase. Increasing the lath width in the Kinetics model had a similar effect on the austenitization Kinetics as increasing the heating-rate.
D. S. Kim - One of the best experts on this subject based on the ideXlab platform.
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Cure and thermal decomposition Kinetics of a DGEBA/amine system modified with epoxidized soybean oil
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Y. J. Woo, D. S. KimAbstract:In this study, epoxidized soybean oil (ESO) was added to a typical diglycidyl ether of bisphenol A (DGEBA) epoxy resin system with an amine curing agent, and the cure and thermal decomposition Kinetics of the epoxy resin system were investigated by thermal analyses. ESO content in the epoxy resin system was changed up to 30%, and the stoichiometric amount of ethylene diamine was used. DSC was used for cure Kinetics Analysis, and TGA was used for thermal decomposition Kinetics Analysis. FTIR was used to check the completeness of the polymerization reaction of the cured epoxy resin samples for TGA. With increasing ESO content, cure rate decreased and the beginning temperature of thermal decomposition lowered. The cure and thermal decomposition Kinetics of the epoxy resin system could be successfully analyzed by the autocatalytic reaction mechanism and the Ozawa method respectively.
M. P. Guerrero-mata - One of the best experts on this subject based on the ideXlab platform.
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Stabilisation of ferritic stainless steels with Zr and Ti additions
Materials Science and Technology, 2011Co-Authors: J. L. Cavazos, I. Gomez, M. P. Guerrero-mataAbstract:Traditional 11·5 wt-%Cr ferritic stainless steels are single stabilised with Ti or dual stabilised with Ti–Nb additions. A dual-stabilised ferritic stainless steel 409 with Zr–Ti additions was studied, which was selected through thermodynamic and Kinetics Analysis. The alloy was subjected to thermomechanical processing using both hot and cold rolling and annealing. The intergranular corrosion resistance and microstructure of this alloy was evaluated. Of particular interest was to study the stabilisation behaviour of this alloy under all processing conditions. The results showed that the precipitation of CrxCy was effectively prevented; hence, the alloy used in this investigation had an excellent resistance to intergranular corrosion.
Hanping Chen - One of the best experts on this subject based on the ideXlab platform.
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thermal behavior and reaction Kinetics Analysis of pyrolysis and subsequent in situ gasification of torrefied biomass pellets
Energy Conversion and Management, 2018Co-Authors: Haiping Yang, Jim C Lim, Hanping ChenAbstract:Abstract Torrefaction followed by densification improves the heating value, grindability, and logistical treatment efficiency of biomass. Study of the pyrolysis and gasification of torrefied biomass pellets has great significance for the efficient conversion and utilization of biomass. In this study, the thermal behavior and reaction Kinetics of pyrolysis and following in-situ CO2 gasification of torrefied corn stalk pellets were investigated in a macro-thermogravimetric analyzer. Torrefaction reduced the amounts of volatiles released during pyrolysis and the maximum pyrolysis rate of pellets decreased with the increase of torrefaction temperature. A three-pseudocomponent model applied for the pellet pyrolysis process suggested that the contribution of hemicellulose reduced as indicated by a decrease in activation energy, while lignin contributed more to the overall Kinetics with the increased torrefaction temperature. The gasification of chars after the pyrolysis of torrefied pellets based on the nucleation and growth model indicated that as the torrefaction temperature increased, the gasification reactivity decreased, as implied by the evolutions of pore structures, ash compositions and graphitized crystal structures of the pellet pyrolysis chars. The higher activation energy increased the reaction resistance during the pellet gasification process. The results showed that torrefaction and densification together influenced the reaction behavior, reactivity and overall Kinetics of biomass.
Rudolf Metkemeijer - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamics and Kinetics Analysis of gasoline reforming assisted by arc discharge
Energy and Fuels, 2008Co-Authors: Jean-damien Rollier, Guillaume Petitpas, José Gonzalez-aguilar, Adeline Darmon, Laurent Fulcheri, Rudolf MetkemeijerAbstract:Onboard hydrogen production out of hydrocarbons for fuel cells is subject to problems when using traditional catalytic reformers. High device weight, a relatively long transient time, and catalyst poisoning all serve to make their integration in a vehicle complex. In response to these challenges, reforming processes based on cold plasma have been recently implemented. This paper presents a theoretical Analysis of hydrogen production out of gasoline assisted by arc discharge. A wide range of O/C and H2O/C ratios (including partial oxidation and pure steam reforming) have been investigated, together with different forms of injected power and reactor conditions. Both thermodynamic equilibrium and kinetic calculations (e.g., perfectly stirred reactor, plug flow reactor) were performed. Thermodynamic equilibrium calculations provide theoretical upper limits of the process via input parameters, while the kinetic computations provide a more realistic estimation of both output composition and process efficiency.
