检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2023年第9期44卷 1563-1576页

作者： s.i.abdelsalam A.Z.ZAHER instituto de Ciencias MatemHu DiNGticas iCMAT Madrid 28049Spain Basic science Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt Basic science Department Faculty of EngineeringShubra-Benha UniversityCairo 11884Egypt

in this article,an investigation is conducted to study the precise role of zirconium nanoparticles that exist in a slime-like fluid subject to specific *** gliding is a technique of mobility used by bacteria that lack motility components,bacteria travel on their own strength in gliding locomotion by secreting a layer of slime on the substrate.A model of an undulating sheet over a layer of slime of a Rabinowitsch fluid is investigated as a potential model of bacteria’s gliding *** the aid of long wavelength approximation,the equations governing the circulation of slime underneath the cells are established and analytically *** effects of pseudoplasticity,dilatation and non-Newtonian parameter on the behavior of zirconium concentration,speed of microorganism(bacteria),streamline patterns,and pressure rise for non-Newtonian and Newtonian fluids are *** power required for propulsion is also *** interpretation for the pertinent variables has been graphically discussed against the parameters under *** is found that with the increase in the concentration of zirconium nanoparticles,the bacterial flow is accelerated and attains its maximum near the rigid substrate wall while an opposite behavior is noticed in the rest region.

关键词： zirconium nanoparticle gliding bacterium Grashof heat transfer glider's speed Rabinowitsch fluid

Anomalous reactivity of thermo-bioconvective nanofluid towards oxytactic microorganisms

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 711-724页

作者： s.i.abdelsalam M.M.BHATTi Basic science Department Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt instituto de Matemáticas-Juriquilla Universidad Nacional Autónoma de MéxicoBlvd.Juriquilla 3001Quer´etaro 76230M´exico College of Mathematics and systems science Shandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina

The peristaltic flow of a non-Newtonian nanofluid with swimming oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented *** is noticed that the pressure rise and friction forces attain smaller values for the endoscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, e.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

关键词： oxytactic swimming microorganism swimming variable magnetic field blood clotting endoscopy non-Newtonian fluid

Performance enhancement of a DC-operated micropump with electroosmosis in a hybrid nanofluid:fractional Cattaneo heat flux problem

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 931-944页

作者： A.M.ALsHARiF A.i.ABDELLATEEF Y.A.ELMABOUD s.i.abdelsalam Department of Mathematics and statistics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Applied Mathematics and science Faculty of EngineeringNational University of Science and TechnologySeeb 111Sultanate of Oman Department of Mathematics College of Science and Arts at KhulisUniversity of JeddahJeddah 21589Saudi Arabia Department of Mathematics Faculty of ScienceAl-Azhar University(Assiut Branch)Assiut 71254Egypt Department of Basic science Faculty of EngineeringThe British University in EgyptCairo 11837Egypt

The purpose of this investigation is to theoretically shed some light on the effect of the unsteady electroosmotic flow(EOF)of an incompressible fractional secondgrade fluid with low-dense mixtures of two spherical nanoparticles,copper,and *** flow of the hybrid nanofluid takes place through a vertical micro-channel.A fractional Cattaneo model with heat conduction is *** the DC-operated micropump,the Lorentz force is responsible for the pressure difference through the *** Debye-H¨ukel approximation is utilized to linearize the charge *** semianalytical solutions for the velocity and heat equations are obtained with the Laplace and finite Fourier sine transforms and their numerical *** addition to the analytical procedures,a numerical algorithm based on the finite difference method is introduced for the given domain.A comparison between the two solutions is *** variations of the velocity heat transfer against the enhancements in the pertinent parameters are thoroughly investigated *** is noticed that the fractional-order parameter provides a crucial memory effect on the fluid and temperature *** present work has theoretical implications for biofluid-based microfluidic transport systems.

关键词： hybrid nanofluid fractional Cattaneo heat flux Caputo-Fabrizio derivative

interaction between compressibility and particulate suspension on peristaltically driven flow in planar channel

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第1期38卷 137-154页

作者： i.M.ELDEsOKY s.i.abdelsalam R.M.ABUMANDOUR M.H.KAMEL K.VAFAi Department of Basic Engineering sciences Faculty of EngineeringMenoufia UniversityMenoufia 32511Egypt Department of Mechanical Engineering University of CaliforniaCalifornia 92521U.S.A. Basic science Department Faculty of EngineeringThe British University in EgyptCairo 11837Egypt Department of Engineering Mathematics and Physics Faculty of Engineering Cairo UniversityGiza 12613Egypt

The peristaltic pumping of a viscous compressible liquid mixed with rigid spherical particles of the same size in a channel is theoretically investigated. The momentum equations for the compressible flow are solved with a perturbation analysis. The analysis is carried out by duly accounting for the nonlinear convective acceleration terms for the fluid part on the wavy wall. The zeroth-order terms yield the Poiseuille flow, and the first-order terms give the Orr-sommerfeld equation. The explicit expression for the net axial velocity is derived. The effects of the embedded parameters on the axial fluid velocity are studied through different engineering applications. The features of the flow characteristics are analyzed and discussed in detail. The obtained results are evaluated for various parameters associated with the blood flow in the blood vessels with diameters less than 5 500 μm, whereas the particle diameter has been taken to be 8 μm. This study provides a scope to evaluate the effect of the theory of two-phase flow characteristics with compressible fluid problems, and is helpful for understanding the role of engineering applications of pumping solid-fluid mixture by peristaltically driven motion.

关键词： two-phase flow peristaltic transport compressible liquid perturbation method

Couple stress fluid flow in a rotating channel with peristalsis

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2018年第2期30卷 307-316页

作者： Y.Abd elmaboud sara i.abdelsalam Kh.s.Mekheimer Mathematics Department Faculty of Science and Arts Khulais University Of Jeddah Mathematics Department Faculty of Science Al-Azhar University (Assiut Branch) Department of Mechanical Engineering University of CaliforniaRiverside USA Basic science Department Faculty of Engineering The British University in Egypt Mathematics Department Faculty of Science Al-Azhar University

This article describes a new model for obtaining closed-form semi-analytical solutions of peristaltic flow induced by sinusoidal wave trains propagating with constant speed on the walls of a two-dimensional rotating infinite channel. The channel rotates with a constant angular speed about the z-axis and is filled with couple stress fluid. The governing equations of the channel deformation and the flow rate inside the channel are derived using the lubrication theory approach. The resulting equations are solved, using the homotopy perturbation method（HPM）, for exact solutions to the longitudinal velocity distribution, pressure gradient, flow rate due to secondary velocity, and pressure rise per wavelength. The effect of various values of physical parameters, such as, Taylor＇s number and couple stress parameter, together with some interesting features of peristaltic flow are discussed through graphs. The trapping phenomenon is investigated for different values of parameters under consideration. it is shown that Taylor＇s number and the couple stress parameter have an increasing effect on the longitudinal velocity distribution till half of the channel, on the flow rate due to secondary velocity, and on the number of closed streamlines circulating the bolus.

关键词： Homotopy perturbation method (HPM) couple stress fluid rotating channel peristaltic transport

simultaneous effects of magnetic field and space porosity on compressible Maxwell fluid transport induced by a surface acoustic wave in a microchannel

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第12期22卷 323-332页

作者： Khaled s.Mekheimer soliman R.Komy sara i.abdelsalam Mathematics & statistics Department Faculty of Science Taif University Department of Mathematics Faculty of Science (Men) Al-Azhar University Department of Mathematics Faculty of Science Helwan University Basic science Department Faculty of Engineering The British University in Egypt

Peristaltic motion induced by a surface acoustic wave of a viscous, compressible and electrically conducting Maxwell fluid in a confined parallel-plane microchannel through a porous medium is investigated in the presence of a constant magnetic field. The slip velocity is considered and the problem is discussed only for the free pumping case. A perturbation technique is employed to analyze the problem in terms of a small amplitude ratio. The phenomenon of a “backward flow” is found to exist in the center and at the boundaries of the channel. in the second order approximation, the net axial velocity is calculated for various values of the fluid parameters. Finally, the effects of the parameters of interest on the mean axial velocity, the reversal flow, and the perturbation function are discussed and shown graphically. We find that in the non-Newtonian regime, there is a possibility of a fluid flow in the direction opposite to the propagation of the traveling wave. This work is the most general model of peristalsis created to date with wide-ranging applications in biological, geophysical and industrial fluid dynamics.

关键词： peristaltic flow Maxwell fluid porous medium slip flow microchannel

Arctic sea-ice extent: No record minimum in 2023 or recent years

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic science Letters 2025年第1期18卷 52-55页

作者： Ola M.Johannessen Tor i.Olaussen Nansen scientific society BergenNorway Nansen Environmental and Remote sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in september. On 11 september 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in september, while the remainder is caused by natural variability.

关键词： sea ice Arctic Minimum ice Climate

Coarse to Fine: The Role of severe Plastic Deformation in Advancing Titanium-Based Medical implants - A Comprehensive Review

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials science) 2025年第1期40卷 295-306页

作者： Dragana R Mihajlović Bojan i Međo ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča institute of Nuclear sci-ences-National institute of the Republic of serbia University of Belgrade11001BeogradSerbia innovation Centre of the Faculty of Technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

This paper describes severe plastic deformation(sPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the sPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPT)process,as one of the sPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPT process parameters,primarily hydrostatic pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the sPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties

Revisiting cerebral endothelial cells in Alzheimer’s disease

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第10期20卷 2911-2912页

作者： Amira s.Hanafy Department of Neurosurgery University Hospital BonnBonnGermany

Alzheimer’s disease(AD)is the most common neurodegenerative disorder characterized by slow and progressive decline of cognitive and memory *** only approximately 5%of the cases,AD is familial,as often predisposed by genetic mutations(Hoogmartens et al.,2021),while sporadic AD accounts for approximately 95%of the *** amyloid cascade hypothesis is one of the fundamental hypotheses put out to explain AD pathogenesis as dysregulated homeostasis of amyloid-β(Aβ)peptides that leads to the accumulation of Aβplaques in the parenchyma,an anatomical hallmark of AD.

关键词： Alzheimer Aβ cerebral

Deciphering the mechanobiology of microglia in traumatic brain injury with advanced microsystems

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第8期20卷 2304-2306页

作者： Anthony Procès sylvain Gabriele Univ.Grenoble Alpes InsermU1216Grenoble Institut des NeurosciencesGrenobleFrance Mechanobiology&Biomaterials Group CIRMAPResearch Institute for BiosciencesUniversity of MonsMonsBelgium

Advanced microsystems in traumatic brain injury research:Traumatic brain injury(TBi)results from a mechanical insult to the brain,leading to neuronal and axonal damage and subsequently causing a secondary *** minutes ... 详细信息

关键词： traumatic injury damage