The Experts below are selected from a list of 46974 Experts worldwide ranked by ideXlab platform
Huining Xiao - One of the best experts on this subject based on the ideXlab platform.
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al mcm 48 as a potential hydrotreating catalyst support ii Diffusion property study
Microporous and Mesoporous Materials, 2008Co-Authors: Ling Huang, Qinlin Huang, Huining XiaoAbstract:Abstract Mesoporous alumina MCM-48 materials (denoted as Al-MCM-48) were synthesized as a potential hydrotreating catalyst supports for light-cycle oil (LCO). Diffusion Phenomenon of typical large di-aromatic in LCO (i.e., 1-methylnaphthalene) in MCM-48, Al-MCM-48 samples and reference H-USY zeolite, and small aromatic (i.e., toluene) in one Al-MCM-48 sample were studied with the aid of standard zero length column (ZLC) technique. The influences of Si/Al ratio, dimension of aromatic molecule and the post-synthesis hydrothermal restructuring treatment on the Diffusion behaviors have been investigated. Compared with conventional catalyst support like H-USY zeolite, Al-MCM-48 samples showed faster Diffusion for 1-methylnaphthalen, demonstrating its advantage as a promising catalyst support. The Diffusion results revealed that Si/Al ratio was an important factor for the transport process, which should be optimized. Post-synthesis treatment enhanced the Diffusion of 1-methylnaphthalene but with limitation. The results also indicated that the overall Diffusion of aromatic compounds in LCO was controlled by the mobility of di-aromatic molecules (i.e., 1-methylnaphthalene). Therefore, it is critical to select a catalyst support with improved Diffusion of large di-aromatic molecules.
Frédéric Lagoutière - One of the best experts on this subject based on the ideXlab platform.
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probabilistic analysis of the upwind scheme for transport equations
Archive for Rational Mechanics and Analysis, 2011Co-Authors: François Delarue, Frédéric LagoutièreAbstract:We provide a probabilistic analysis of the upwind scheme for d-dimensional transport equations. We associate a Markov chain with the numerical scheme and then obtain a backward representation formula of Kolmogorov type for the numerical solution. We then understand that the error induced by the scheme is governed by the fluctuations of the Markov chain around the characteristics of the flow. We show, in various situations, that the fluctuations are of diffusive type. As a by-product, we recover recent results due to Merlet and Vovelle (Numer Math 106: 129–155, 2007) and Merlet (SIAM J Numer Anal 46(1):124–150, 2007): we prove that the scheme is of order 1/2 in \({L^{\infty}([0,T],L^1(\mathbb R^d))}\) for an integrable initial datum of bounded variation and of order 1/2−e, for all e > 0, in \({L^{\infty}([0,T] \times \mathbb R^d)}\) for an initial datum of Lipschitz regularity. Our analysis provides a new interpretation of the numerical Diffusion Phenomenon.
Ruoxu Wang - One of the best experts on this subject based on the ideXlab platform.
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the interface microstructure and mechanical properties of niobium 316l stainless steel explosively welded composite plate
Journal of Materials Engineering and Performance, 2020Co-Authors: Ruoxu Wang, Teng Tan, Yulu Huang, Qingwei Chu, Feng Pan, S H Zhang, Xingyi ZhangAbstract:In order to manufacture stainless steel helium vessels for the superconducting radio frequency (SRF) cavities, niobium-316L stainless steel composite plates were fabricated by explosive welding technique. The microstructure and mechanical properties of the composite plates were investigated both right after explosive welding and after annealing. The microstructure measurement results demonstrated that there was not any brittle intermetallic layer formed nor any Diffusion Phenomenon observed after heat treatment processes. Due to the plastic deformation and work hardening near the interface, the hardness of the composite plates was higher near the bonding interface than inside the bulk metal regions. Meanwhile, ultimate tensile strength and shear strength of the composite plate reached their maximum values when the sample was annealed at 873 K for 10 h at room temperature. Charpy impact test results at liquid helium results showed that the toughness of composite plate meets the requirements from the SRF cavities’ helium vessels fabrication.
Xingyi Zhang - One of the best experts on this subject based on the ideXlab platform.
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the interface microstructure and mechanical properties of niobium 316l stainless steel explosively welded composite plate
Journal of Materials Engineering and Performance, 2020Co-Authors: Ruoxu Wang, Teng Tan, Yulu Huang, Qingwei Chu, Feng Pan, S H Zhang, Xingyi ZhangAbstract:In order to manufacture stainless steel helium vessels for the superconducting radio frequency (SRF) cavities, niobium-316L stainless steel composite plates were fabricated by explosive welding technique. The microstructure and mechanical properties of the composite plates were investigated both right after explosive welding and after annealing. The microstructure measurement results demonstrated that there was not any brittle intermetallic layer formed nor any Diffusion Phenomenon observed after heat treatment processes. Due to the plastic deformation and work hardening near the interface, the hardness of the composite plates was higher near the bonding interface than inside the bulk metal regions. Meanwhile, ultimate tensile strength and shear strength of the composite plate reached their maximum values when the sample was annealed at 873 K for 10 h at room temperature. Charpy impact test results at liquid helium results showed that the toughness of composite plate meets the requirements from the SRF cavities’ helium vessels fabrication.
Julien Bras - One of the best experts on this subject based on the ideXlab platform.
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active bio based food packaging Diffusion and release of active substances through and from cellulose nanofiber coating toward food packaging design
Carbohydrate Polymers, 2016Co-Authors: Nathalie Lavoine, Valerie Guillard, Isabelle Desloges, Nathalie Gontard, Julien BrasAbstract:Abstract Cellulose nanofibers (CNFs) were recently investigated for the elaboration of new functional food-packaging materials. Their nanoporous network was especially of interest for controlling the release of active species. Qualitative release studies were conducted, but quantification of the Diffusion Phenomenon observed when the active species are released from and through CNF coating has not yet been studied. Therefore, this work aims to model CNF-coated paper substrates as controlled release system for food-packaging using release data obtained for two model molecules, namely caffeine and chlorhexidine digluconate. The applied mathematical model – derived from Fickian Diffusion – was validated for caffeine only. When the active species chemically interacts with the release device, another model is required as a non-predominantly Diffusion-controlled release was observed. From caffeine modeling data, a theoretical active food-packaging material was designed. The use of CNFs as barrier coating was proved to be the ideal material configuration that best meets specifications.