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Moore-Gibson-Thompson theory for thermoelastic dielectrics

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Applied Mathematics and Mechanics(English Edition) 2021年第2期42卷 309-316页

作者： J.r.FErNANDEZ r.quintanilla Department of Applied Mathematics I University of VigoCampus As Lagoas MarcosendeVigo 36310Spain Department of Mathematics Polytechnic University of CataloniaTerrassa 08222Spain

We consider the system of equations determining the linear thermoelastic deformations of dielectrics within the recently called Moore-Gibson-Thompson(MGT)***,we obtain the system of equations for such a ***,we consider the case of a rigid solid and show the existence and the exponential decay of ***,we consider the thermoelastic case and obtain the existence and the stability of the *** decay of solutions in the one-dimensional case is also recalled.

关键词： Moore-Gibson-Thompson(MGT)thermoelastic dielectrics existence semigroup exponential decay

NUMErICAL ANALYSIS OF A PrOBLEM INVOLVING A VISCOELASTIC BODY WITH DOUBLE POrOSITY

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Journal of Computational Mathematics 2022年第3期40卷 415-436页

作者： Noelia Bazarra Jose r.Fernandez MariCarme Leseduarte Antonio Magana ramon quintanilla Departamento de Matematica Aplicada I Universidade de VigoETSI TelecomunicacionCampus As Lagoas Marcosende s/n36310 VigoSpain Departamento de Matematicas E.S.E.I.A.A.T.-U.P.C.Colom 1108222 TerrassaBarcelonaSpain

We study from a numerical point of view a multidimensional problem involving a viscoelastic body with two porous *** mechanical problem leads to a linear system of three coupled hyperbolic partial differential *** corresponding variational formulation gives rise to three coupled parabolic linear *** existence and uniqueness result,and an energy decay property,are ***,fully discrete approximations are introduced using the finite element method and the implicit Euler scheme.A discrete stability property and a priori error estimates are proved,from which the linear convergence of the algorithm is derived under suitable additional regularity ***,some numerical simulations are performed in one and two dimensions to show the accuracy of the approximation and the behaviour of the solution.

关键词： Viscoelasticity with double porosity Finite elements A priori estimates Numerical simulations

Use of silica nanopowder to accelerate CO_2 sorption by Ca(OH)_2

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Particuology 2013年第4期11卷 448-453页

作者： M.A.S.quintanilla J.M.Valverde Faculty of Physics University of SevilleAvenida Reina Mercedes s/n

Promising technologies have recently emerged to capture CO2 from postcombustion flue gas and to enhance the production of hydrogen from natural gas by steam-methane reforming, on the basis of sorp- tion of CO2 by Ca-based powders. The rate of CO2 sorption on Ca-based powders is limited by both carbonation kinetics and transport of CO2 to unreacted sorption sites. Ca-based powders may exhibit cohesive aggregation, thus hindering gas-solids contact efficiency. In our work, we tested the sorption rate of powder samples prepared by dry mixing of a cohesive Ca（OH）2 powder with a silica nanopowder used as additive. The silica nanopowder serves to improve the dispersibility of Ca（OH）2. Consequently, when a CO2 enriched gas and the modified sorbent are brought into contact, the rate of CO2 sorption is enhanced in the initial fast phase of interest for practical applications.

关键词： FluidizationFine powdersCO2 sorptionNanoparticles

regular Global Attractors of Type Ⅲ Thermoelastic Extensible Beams

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Chinese Annals of Mathematics,Series B 2010年第5期31卷 619-630页

作者： Michele COTI ZELATI Vittorino PATA ramon quintanilla Mathematics Department Indiana UniversityRawles Hall Dipartimento di Matematica "F. Brioschi" Politecnico di Milano Matemtica Aplicada 2 ETSEIAT-UPC Terrassa

For β∈ r,the authors consider the evolution system in the unknown variables u and ααttu+αxxxxu+αxxtα-(β+αxu L22)αxxu=f,αttα-αxxα-αxxtα-αxxtu=0 describing the dynamics of type III thermoelastic extensible beams,where the dissipation is entirely contributed by the second equation ruling the evolution of the thermal displacement α.Under natural boundary conditions,the existence of the global attractor of optimal regularity for the related dynamical system acting on the phase space of weak energy solutions is established.

关键词： Type III thermoelastic extensible beam Lyapunov functional Global attractor

Evaluation of different Krylov subspace methods for simulation of the water faucet problem

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Nuclear Science and Techniques 2021年第5期32卷 1-16页

作者： Hong-Yang Wei Kevin Briggs Victor.quintanilla Yi-Tung Chen Department of Mechanical Engineering University of NevadaLas VegasNV 89154USA

In this study,a one-dimensional two-phase flow four-equation model was developed to simulate the water faucet *** performance of six different Krylov subspace methods,namely the generalized minimal residual(GMrES),transpose-free quasi-minimal residual,quasi-minimal residual,conjugate gradient squared,biconjugate gradient stabilized,and biconjugate gradient,was evaluated with and without the application of an incomplete LU(ILU)factorization preconditioner for solving the water faucet *** simulation results indicate that using the ILU preconditioner with the Krylov subspace methods produces better convergence performance than that without the ILU *** the GMrES demonstrated an acceptable convergence performance under the Krylov subspace methods without the *** velocity and pressure distribution in the water faucet problem could be determined using the Krylov subspace methods with an ILU preconditioner,while GMrES could determine it without the need for a ***,there are significant advantages of using an ILU preconditioner with the GMrES in terms of *** different Krylov subspace methods showed similar performance in terms of computational efficiency under the application of the ILU preconditioner.

关键词： Water faucet problem Krylov subspace methods ILU preconditioner

Convergence in leaf phenology traits of two understorey ferns in the northwestern Iberian Peninsula

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Journal of Plant Ecology 2018年第1期11卷 92-102页

作者： Luis G.quintanilla Beatriz Pías Department of Biology and Geology Physics and Inorganic ChemistrySchool of Environmental Sciences and TechnologyRey Juan Carlos Universityc/Tulipán s/n28933 MóstolesMóstolesSpain Department of Plant Sciences Faculty of BiologyComplutense of Madrid UniversityMadridSpain

Aims Plants control leaf phenology to maximize annual photosynthetic *** ferns play an important ecological role in many habitats,especially forests,their phenology traits have been poorly ***,we investigate the leaf phenology of two ferns of the forest understorey and analyse the relationship between the timing of leaf emergence and spore dispersal and the effect of between-year climatic *** We compared the leafing and sporing phenologies of two ferns with very large(>2 m),overwintering leaves:Culcita macrocarpa and Woodwardia *** regularly monitored individuals of six popu-lations in the northwestern Iberian Peninsula during a 3-year *** studied eight phenology variables:leafing start date,leafing end date,leaf expansion time,number of new leaves per individual,between-individual synchrony,within-individual synchrony,percentage of fertile leaves and spore release *** also determined leaf mass per area(LMA)and gathered data on air temperature and *** findings Both *** and *** produce few leaves(~2 leaves individual−1 year−1),which expand simultaneously for a very long period(from midwinter to early summer),are retained for more than 1 year(37 and 19 months,respectively)and have relatively high *** traits,together with large leaf size,have also been found in seed plants from the forest understorey and represent adap-tations to this light-limited *** of both study ferns are simultaneously released in late winter,with little between-year variation caused by differences in air *** remarkable similarity between species suggests that the convergence in tim-ing of leaf emergence favours the convergence in timing of spore dispersal.

关键词： Culcita macrocarpa leaf phenology spore dispersal temperate forest Woodwardia radicans

Effect of magnetic field orientation on fluidized beds of magnetic particles:Theory and experiment

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Particuology 2014年第1期12卷 54-63页

作者： Miguel ángel Sánchez quintanilla Manuel Jesús Espin José Manuel Valverde Department of Electronics and Electromagnetism University of Seville Department of Applied PhysicsⅡ University of Seville

Geldart-A fluidized beds of fine particles experience a jamming transition between a fluid-like state and a solid-like state at a certain superficial gas velocity, that depends on the relative strength of interparticle attractive forces with respect to particle weight, lnterparticle forces provide the bed with a certain tensile strength in the jammed state. In the work presented here we analyze the behavior of a fluidized bed of magnetic particles subjected to an externally applied magnetic field, which contributes to enhance interparticle forces. The importance of the magnetic contribution to interparticle forces is measured by the changes in the tensile strength and the superficial gas velocity at the jamming transition. The link of the field orientation with the microstructure of the bed is discussed,

关键词： Magneto-fluidization Jamming transition Fluidization Fine powders Cohesion Magnetization

Ectopic papilla of Vater in the pylorus

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World Journal of Gastroenterology 2009年第41期15卷 5221-5223页

作者： Iván Guerra Luis ramón rábago Fernando Bermejo Elvira quintanilla Silvia García-Garzón Gastroenterology Service University Hospital Severo Ochoa Leganés 28911 Madrid Spain

The major papilla of Vater is usually located in the second portion of the duodenum, to the posterior medial wall. Sometimes the mouth of the biliary duct is located in other areas. Drainage of the common bile duct into the pylorus is extremely rare. A 73-year old man, with a history of duodenal ulcer, was admitted to hospital with the diagnosis of cholangitis. Dilatation of the extrahepatic biliary duct was observed by abdominal ultrasonography, and endoscopic retrograde cholangiopancreatography （ErCP） was performed. No area suggesting the presence of the papilla of Vater was found within the second duodenal portion. Finally the major papilla was located in the theoretical pyloric duct. Cholangiography was performed and choledocholithiasis was found in the biliary tree. The patient underwent dilatation of the papilla with a balloon tyre and removal of a 7 mm stone using a Dormia basket, which solved the problem without further complications. This anomaly increased the difficulty of performing therapeutic interventions during ErCr This alteration in anatomy may increase the risk of complications during papillotomy, with a theoretically higher risk of perforation. Dilatation using a balloon was the chosen therapeutic technique both in our case and in the literature, due to its low rate of complications.

关键词： Ectopic common bile duct Endoscopic dilatation Endoscopic retrograde cholangiopancreatog- raphy Papilla of Vater Papillotomy Pyloric drainage

The use of fibroblasts as a valuable strategy for studying mitochondrial impairment in neurological disorders

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Translational Neurodegeneration 2022年第1期11卷 401-425页

作者： Margrethe A.Olesen Francisca Villavicencio-Tejo rodrigo A.quintanilla Laboratory of Neurodegenerative Diseases Facultad de Ciencias de La SaludInstituto de Ciencias BiomédicasUniversidad Autónoma de ChileSantiagoChile

Neurological disorders(NDs)are characterized by progressive neuronal dysfunction leading to synaptic failure,cognitive impairment,and motor *** these diseases,Alzheimer’s disease(AD),Parkinson’s disease(PD),Huntington’s disease(HD),and amyotrophic lateral sclerosis(ALS)have raised a significant research *** disorders present common neuropathological signs,including neuronal dysfunction,protein accumulation,oxidative damage,and mitochondrial *** this context,mitochondrial impairment is characterized by a deficiency in ATP production,excessive production of reactive oxygen species,calcium dysregulation,mitochondrial transport failure,and mitochondrial dynamics *** defects in mitochondrial health could compromise the synaptic process,leading to early cognitive dysfunction observed in these ***,skin fibroblasts from AD,PD,HD,and ALS patients have been suggested as a useful strategy to investigate and detect early mitochondrial abnormalities in these *** this context,fibroblasts are considered a viable model for studying neurodegenerative changes due to their metabolic and biochemical relationships with ***,studies of our group and others have shown impairment of mitochondrial bioenergetics in fibroblasts from patients diagnosed with sporadic and genetic forms of AD,PD,HD,and ***,these mitochondrial abnormalities have been observed in the brain tissues of patients suffering from the same ***,fibroblasts represent a novel strategy to study the genesis and progression of mitochondrial dysfunction in AD,PD,HD,and *** review discusses recent evidence that proposes fibroblasts as a potential target to study mitochondrial bioenergetics impairment in neurological disorders and consequently to search for new biomarkers of neurodegeneration.

关键词： Mitochondria Fibroblasts Cell reprogramming Alzheimer’s disease Parkinson’s disease Huntington’s disease Amyotrophic lateral sclerosis Mitochondrial dysfunction