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mixed convection stagnation-point flow on vertical stretching sheet with external magnetic field

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Applied mathematics and mechanics(English Edition) 2014年第2期35卷 155-166页

作者： F.m.ALi R.nAZAR n.m.ARiFin i.POP Department of mathematics & institute for mathematical Research Universiti Putra Malaysia UPM School of mathematical Sciences Faculty of Science & TechnologyUniversitiKebangsaan Malaysia UKM Department of mathematics Babes-Bolyai University

The problem of steady laminar magnetohydrodynamic （mHD） mixed con- vection stagnation-point flow of an incompressible viscous fluid over a vertical stretch- ing sheet is studied. The effect of an externally magnetic field is taken into account. The transformed boundary layer equations are solved numerically by using an implicit finite-difference scheme. numerical results are obtained for various values of the mixed convection parameter, Hartmann number, and Prandtl number. The effects of an exter- nally magnetic field on the skin friction coefficient, local nusselt number, velocity, and temperature profiles for both A 〉 1 and A ~ 1, where A is the velocity ratio parameter, are presented graphically and discussed in detail. Both assisting and opposing flows are considered, and it is found that dual solutions exist for the opposing flow.

关键词： boundary layer mixed convection magnetohydrodynamic (mHD) numer-ical result stagnation-point stretching sheet

Synthesis,structure and magnetic properties of Sm_(1.2)Ho_(0.8)Fe_(17)Hx(X=0;4.4)

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Journal of Rare Earths 2021年第9期39卷 1089-1094页

作者： S.V.Veselova m.A.Paukov i.S.Tereshina V.n.Verbetsky K.V.Zakharov D.i.Gorbunov A.n.VasiPev Faculty of Physics M.V.Lomonosov Moscow State UniversityMoscow 119991Russia nuclear Fuel Cycle Department.Centrum Vyzkumu Rez Hlavni 130Husinec-Rez 25068.Czech Republic immanuel Kant Baltic Federal University Kaliningrad 236004Russia Faculty of mathematics and Physics Charles UniversityPrague 12116Czech Republic Hochfeld-magnetlabor Dresden(HLD-emFL) Helmholtz-Zentrum Dresden-RossendorfDresden 07328Germany f National Research South Ural State UniversityChelyabinsk 454080Russia

intermetallic compounds based on rare-earth metals and iron are by far the most promising materials for permanent mag *** this work,the multicomponent compound Sm_(1.2)Ho_(0.8)Fe_(17)was prepared by in duction *** hydride Sm_(1.2)Ho_(0.8)Fe_(17)H_(4.4)with a high hydrogen content was obtained by direct hydrogenation of the intermetallic *** rhombohedral Th2Zn17-type of structure(space group R3^(-)m)is inhere nt to parent compound and hydride as *** effect of hydrogenation on the magneric properties of Sm_(1.2)Ho_(0.8)Fe_(17)was *** temperature of the hydride Sm_(1.2)Ho_(0.8)-Fe_(17)H_(4.4)is higher than that of parent compound by△Tc=138 *** hydrogen embedded in Sm_(1.2)Ho_(0.8)Fe_(17)crystal lattice in creases the saturation magnetization(σs)at T=300 K,but does not significantly affect%at T=4.2 *** ferrimagnetic structure is retained in magnetic fields up to 58 T in the parent compound,while,in the hydride,there is a spin-reorie ntatio n phase transitio n observed at 55 *** is found that the parameter of the in tersublattice exchange interaction decreases significantly in the hydride Sm_(1.2)Ho_(0.8)Fe_(17)Hg_(4.4)(and in the nitride Sm_(1.2)Ho_(0.8)Fe_(17)n_(2.4))which is associated with boosting of the unit-cell volume and distances between magnetic ions.

关键词： intermetallic compound Hydride Crystal structure magnetization magnetic phase transition Exchange interaction

numerical solution of thermo-solutal mixed convective slip flow from a radiative plate with convective boundary condition

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Journal of Hydrodynamics 2016年第3期28卷 451-461页

作者： m.j.uddin o.anwar bég m.n.uddin a.i.md.ismail Department of mathematics American International University-BangladeshDhakaBangladesh Fluid mechanics Spray Research GroupPetroleum and Gas Engineering DivisionRoom G77Newton BuildingSchool of ComputingScience and Engineering(CSE)University of SalfordM54WTUK Department of mathematical Sciences Ball State University2000 W University AvenueMuncieIN 47306USA School of mathematical Sciences Universiti Sains MalaysiaPenang 11800Malaysia

A mathematical model for mixed convective slip flow with heat and mass transfer in the presence of thermal radiation is presented. A convective boundary condition is included and slip is simulated via the hydrodynamic slip parameter. Heat generation and absorption effects are also incorporated. The Rosseland diffusion flux model is employed. The governing partial differential conservation equations are reduced to a system of coupled, ordinary differential equations via Lie group theory method. The resulting coupled equations are solved using shooting method. The influences of the emerging parameters on dimensionless velocity, tempera- ture and concentration distributions are investigated. increasing radiative-conductive parameter accelerates the boundary layer flow and increases temperature whereas it depresses concentration. An elevation in convection-conduction parameter also accelerates the flow and temperatures whereas it reduces concentrations. Velocity near the wall is considerably boosted with increasing momentum slip parameter although both temperature and concentration boundary layer thicknesses are decreased. The presence of a heat source is found to increase momentum and thermal boundary layer thicknesses but reduces concentration boundary layer thickness. Excelle- nt correlation of the numerical solutions with previous non-slip studies is dem.nstrated. The current study has applications in bio- reactor diffusion flows and high-temperature chemical materials processing systems.

关键词： slip flow thermal radiation lie group theory heat source/sink materials processing

insights from an academic endeavor into central nervous system drug discovery

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neural Regeneration Research 2025年第6期20卷 1717-1718页

作者： Lieve van Veggel An m.Voets Tim Vanmierlo Rudy Schreiber BiOmED Biomedical Research institute Faculty of Medicine and Life SciencesHasselt UniversityHasseltBelgium Department of Psychiatry and neuropsychology Division of Translational NeuroscienceEuropean Graduate School of NeuroscienceSchool for Mental Health and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands Section of Psychopharmacology Neuropsychology and PsychopharmacologyFaculty of Psychology and NeuroscienceMaastricht UniversityMaastrichtThe Netherlands University mS Center(UmSC) Hasselt-PeltBelgium

Historically,"big pharma"did most central nervous system drug discovery R&D ***,in modern times their"managem.nt reductionism"resulted in disappointing pipelines and pharma resided to(late)development,regulatory approval,and marketing(Thong,2015).This had significant consequences for financing and executing research,resulting in a larger role for funding by governments and patient-organizations and a shift of research to academia(mazzucato,2013).

关键词： academic approval consequences

Simplified approach for design of raft foundations against fault *** i:free-field

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Earthquake Engineering and Engineering Vibration 2008年第2期7卷 147-163页

作者： i. Anastasopoulos n. Gerolymos G. Gazetas m. F. Bransb School of Civil Engineering National Technical University of AthensGreece Civil LecturerEngineeringUniversity of DundeeScotlandUK School of Civil Engineering National Technical University of AthensGreece Civil Engineering University of DundeeScotlandUK

Over the past few decades, earthquake engineering research mainly focused on the effects of strong seismic shaking. After the 1999 earthquakes in Turkey and Taiwan, and thanks to numerous cases where fault rupture caused substantial damage to structures, the importance of faulting-induced deformation has re-emerged. This paper, along with its companion （Part Ⅱ）, exploits parametric results of finite elem.nt analyses and centrifuge model testing in developing a four-step semi-analytical approach for analysis of dip-slip （normal and thrust） fault rupture propagation through sand, its emergence on the ground surface, and its interaction with raft foundations. The present paper （Part Ⅰ） focuses on the effects of faulting in the absence of a structure （i.e., in the free-field）. The semi-analytical approach comprises two-steps： the first deals with the rupture path and the estimation of the location of fault outcropping, and the second with the tectonically- induced displacem.nt profile at the ground surface. in both cases, simple mechanical analogues are used to derive simplified semi-analytical expressions. Centrifuge model test data, in combination with parametric results from nonlinear finite elem.nt analyses, are utilized for model calibration. The derived semi-analytical expressions are shown to compare reasonably well with more rigorous experimental and theoretical data, thus providing a useful tool for a first estimation of near-fault seismic hazard.

关键词： fault rupture semi-analytical expression soil-structure interaction earthquake

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Physical properties and maximum allowable mass-radius relation of complexity-free compact stellar objects within modified f(R,T)gravity formalism

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Chinese Physics C 2024年第7期48卷 273-288页

作者： m.K.jasim S.K.maurya Abdelghani Errehymy Ali Khalid Jassim Kottakkaran Sooppy nisar Abdel-Haleem Abdel-Aty Department of mathematical and Physical Sciences College of Arts and SciencesUniversity of NizwaNizwa 616Sultanate of Oman Astrophysics Research Centre School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa Electrical Engineering Department College of EngineeringMustansiriyah UniversityBaghdadIraq Department of mathematics College of Science and Humanities in AlkharjPrince Sattam bin Abdulaziz UniversityAl KharjSaudi Arabia Department of Physics College of SciencesUniversity of BishaP.O.Box 344Bisha 61922Saudi Arabia

This paper investigates the physical properties and predicted radii of compact stars generated by the Tolman-iV complexity-free model within the background of modified gravity theory,particularly the f(R,T)-gravity theory,under complexity formalism for a spherically symmetric spacetime proposed by ***[Phys Rev D 97:044010,2018].By solving the resulting set of differential equations,we obtain the explicit forms of the energy-momentum(em)tensor components,including the density,radial pressure,and tangential *** influence of the parameterχon various physical properties of the star is thoroughly *** model undergoes a series of rigorous tests to determine its physical *** findings indicate that the model exhibits regularity,stability,and a surface with vanishing *** boundary of this surface is determined by carefully selecting the parameter *** complexity method employed in f(R,T)gravity offers an interesting approach for developing astrophysical models that are consistent with observable events as dem.nstrated by recent *** this regard,we use observational data from the GW190814 event,detected by the LiGO and Virgo observatories,to investigate the validity of the Tolman-iV model in f(R,T)*** analysis includes comparing the model's predictions with the observed characteristics of the compact object involved in the *** addition,data from two-millisecond pulsars,PSR J1614-2230 and PSR J0952-0607,are incorporated to further constrain the theoretical ***,we present a diagram depicting the relationship between the total mass and radius of the compact object candidates for different values ofχ.

关键词： complexity modified gravity compact Stars

nonlinear Temperature Dependence of magnetization of Two-Band Superconductors near Upper Critical Field

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Communications in Theoretical Physics 2007年第5X期48卷 949-952页

作者： i.n. Askerzade Abdus Salam international Center for Theoretical Physics Faculty of Sciences Strada Costeria 11 34014 Trieste Italy institute of Physics Azerbaijan National Academy of Sciences Baku-Az1143 Azerbaijan Physics Department Faculty of Sciences Ankara University 06100 Tandogan Ankara Turkey

Temperature dependence of the magnetization m （T） of two-band superconductors is studied in the vicinity of upper critical field He2 by using a two-band Ginzburg-Landau （GL） theory. it is shown that magnetization m（T） has a nonlinear character due to positive curvature of upper critical field Hc2（T） and temperature dependence of effective Ginzburg-Landau parameter neff（T）. The results are shown to be in qualitative agreem.nt with experimental data for the superconducting magnesium diboride, mgB2.

关键词： two-band superconductivity Ginzburg-Landau theory magnetization

Comparative numerical study of single and two-phase models of nanofluid heat transfer in wavy channel

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Applied mathematics and mechanics(English Edition) 2014年第7期35卷 831-848页

作者： m.m.RASHiDi A.HOSSEini i.POP S.KUmAR n.FREiDOOnimEHR Department of mechanical Engineering Faculty of EngineeringBu-Ali Sina UniversityHamedan 65178-38695 Iran Department of mathematics Babe?Bolyai UniversityCluj-Napoca 400084Romania Department of mathematics National Institute of TechnologyJamshedpur 831014Jharkhand India Young Researchers & Elite Club Hamedan BranchIslamic Azad UniversityHamedan 65181-15743 Iran

The main purpose of this study is to survey numerically comparison of two- phase and single phase of heat transfer and flow field of copper-water nanofluid in a wavy channel. The computational fluid dynamics （CFD） prediction is used for heat transfer and flow prediction of the single phase and three different two-phase models （mixture, volume of fluid （VOF）, and Eulerian）. The heat transfer coefficient, temperature, and velocity distributions are investigated. The results show that the differences between the temperature fie].d in the single phase and two-phase models are greater than those in the hydrodynamic tleld. Also, it is found that the heat transfer coefficient predicted by the single phase model is enhanced by increasing the volume fraction of nanoparticles for all Reynolds numbers; while for the two-phase models, when the Reynolds number is low, increasing the volume fraction of nanoparticles will enhance the heat transfer coefficient in the front and the middle of the wavy channel, but gradually decrease along the wavy channel.

关键词： nanofluid two-phase model wavy channel semi implicit method for pres-sure linked equation (SimPLE) method

Analytical and simulation studies for diode and triode ion beam extraction systems

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Chinese Physics C 2012年第4期36卷 344-349页

作者： m. m. Abdelrahman n. i. Basal S. G. Zakhary Accelerators & ion Sources Department Nuclear Research Center Atomic Energy Authority P.O. Box: 13759 Inchas Atomic Energy Authority

This work is concerned with ion beam dynamics and compares the emittance to aberration ratios of two-and three-electrode extraction systems. The study is conducted with the aid of Version 7 of SimiOn 3D ray-tracing software. The beam dependence on various parameters of the extraction systems is studied and the numerical results lead to qualitative conclusions. ion beam characteristics using diode and triode extraction systems are investigated with the aid of the computer code SimiOn 3 D, Version 7.0. The diode （two electrode extraction system） and triode （three- electrode extraction, acceleration-deceleration system） extraction systems are designed and optimized with different geometric parameters of the electrode system, voltage applied to the extraction electrode, and plasma parameters inside the ion source chamber, as well as by the ion beam space charge. This work attempts to describe the importance of the acceleration-deceleration extraction system. it shows that besides an increase of the beam energy, the ion beam has lower emittance than the two-electrode extraction system. ion beams of the highest quality are extracted whenever the half-angular divergence is minimum for which the perveance current intensity and the extraction gap have optimum value. Knowing the electron temperature of the plasma is necessary to determine plasma potential and the exact beam energy.

关键词： ion beam emittance plasma meniscus space charge ion beam SimiOn computer program