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Chahid Ayouch El-Hassan Essoufi Mouhcine Tilioua 《Computers & Mathematics with Applications》2019,77(5):1347-1357
The present paper deals with global existence of weak solutions of a time-space fractional Landau–Lifshitz–Bloch equation involving the weak Caputo derivative and a fractional Laplacian. We use Faedo–Galerkin method with some commutator estimates in order to prove global existence of weak solutions for the model. The uniqueness is also discussed in a special one dimensional case. 相似文献
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Nancy Cliff Mouhcine Kanouni Cindy Peters Phillip V. Yaneff Karlis Adamsons 《Journal of Coatings Technology and Research》2005,2(5):371-387
One of the challenges of coating plastic substrates for exterior automotive applications involves the tendency for light stabilizers,
which inhibit UV degradation of the coating, to migrate out of the topcoat and into the underlying plastic substrate. The
consequent depletion of the stabilizer from the topcoat could account for significantly poorer durability for coatings applied
on plastic than on a nonpermeable substrate such as steel.
These studies investigate the migration of both nonreactable and reactable UV absorbers (UVAs) and hindered amine light stabilizers
(HALS) in fully formulated 2K urethane coatings applied on thermoplastic olefin (TPO) and steel substrates. Extensive migration
of the nonreactable stabilizers occurs during accelerated exposure of the cured coating, and this migration correlates with
poorer performance on TPO. Functionalization of the stabilizer with a group which covalently reacts into the coating will
prevent much of this migration, and the improved degree of retention of the reactable light stabilizers in the topcoat correlates
with improved performance on TPO substrates. In addition, stabilizer variables, such as the type and extent of functionalization
as well as their chemical structure, have an effect on both the migration and performance of the stabilizers. 相似文献
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Youssef Dahani Abdelkhalek Amahmid Abdelfattah El Mansouri Mouhcine Alouah Safae Hasnaoui 《传热工程》2019,40(1-2):128-146
The present work deals with numerical modeling of mixed convection flow in a two-sided lid driven inclined square enclosure filled with water-Al2O3 nanofluid. The limiting cases of a cavity heated from below and cooled from above and the one differentially heated are recovered respectively for inclination angles 0° and 90°. The moving walls of the cavity are pulled in opposite directions with the same velocity and maintained at constant but different temperatures while the remaining walls are kept insulated. The numerical resolution of the studied problem is based on the lattice Boltzmann method. A parametric study is conducted and a set of graphical results is presented and discussed to illustrate the effects of the presence of nanoparticles and enclosure inclination angle on fluid flow and heat transfer characteristics. The governing parameters of this problem are the Richardson number (varied from 0.1 to 106), the nanoparticles volume fraction (varied from 0 to 0.04) and the inclination angle (varied from 0° to 180°). The critical conditions leading to the transition from monocellular flow to multicellular flow and vice versa are determined. In the common ranges of Richardson number and inclination angle where both monocellular and tri-cellular patterns coexist, the heat transfer is seen to be strongly reduced by the latter. 相似文献
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Heat-transfer corrosion behaviour of an ISO 2379 cast Al alloy was studied in antifreeze radiator coolant under heat-rejecting condition. Extensive analyses of microstructures and corroded surfaces were carried out under the optical microscope, scanning electron microscope equipped with energy dispersive spectroscopy and X-ray diffractometer. Heat-rejecting condition led to a cavitation process and cavities were observed within the α-Al matrix. Crevice corrosion was predominant at oxygen depleted regions in heat-transfer corrosion cell. Al2Cu, Al15(Fe,Mn)3Si2 dendrites, Al4Cu2Mg8Si7 and Si phases served as the effective cathodes resulting microgalvanic corrosion at the anodic site of α-Al matrix. 相似文献
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Philip V. Yaneff Karlis Adamsons Nancy Cliff Mouhcine Kanouni 《Journal of Coatings Technology and Research》2004,1(3):201-212
Loss of light stabilizers from automotive finishes can significantly reduce the durability of coatings on plastic substrates.
Minimizing movement by retaining the stabilizers in the targeted layer can greatly improve coating longevity. This article
examines the migratory patterns of a series of traditional UVA and HALS additives in fully formulated 1K silane crosslinked
coatings applied over both plastic and steel substrates, comparing their migratory patterns to that of reactable light stabilizers
containing hydroxyl functionality.
Analysis of the coating layers with the various UVAs and HALS revealed that functionalization of the light stabilizer with
reactable hydroxy groups can prevent migration into the plastic; whereas nonreactable light stabilizers migrate into lower
coating system layers and even into the plastic substrate. The greatest extent of migration does not occur during initial
cure of the wet coating, but during exposure. Significant depletion of the nonreactable light stabilizers from the topcoat
occurs as early as 1500 hours of Xenon boro/boro exposure.
This paper was awarded first place in the Shelby F. Thames Best Paper Award, at the 30th International Waterborne, High-Solids
and Powder Coatings Symposium, February 26–28, 2003, in New Orleans, LA. 相似文献
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We consider a mathematical model describing magnetization dynamics with inertial effects. The model consists of a modified form of the Landau–Lifshitz–Gilbert equation for the evolution of the magnetization vector in a rigid ferromagnet. We discuss global existence of weak solutions and characterize the \(\omega \) -limit set for the model. 相似文献
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