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Angular Dependence of Lateral and Levitation Forces in Asym.etric Sm.ll m.gnet/Superconducting System.

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Chinese Physics Letters 2007年第9期24卷 2700-2703页

作者： H. m. Al-k.ateeb m. k. alqadi F. Y. Alzoubi N. Y. Ayoub Departm.nt of Physics Jordan University of Science and Technology Irbid Jordan School of Applied Natural Sciences German Jordanian University Amman Jordan

The dipole-dipole interaction m.del is used to calculate the angular dependence of lateral and levitation forces on a sm.ll perm.nent m.gnet and a cylindrical superconductor in the m.issner state lying laterally off the sym.etric axis of the cylinder. Under the assum.tion that the lateral displacem.nt of the m.gnet is sm.ll com.ared with the physical dim.nsions of the system. we obtain analytical expressions for the lateral and levitation forces as functions of geom.trical param.ters of the superconductor as well as the height, the lateral displacem.nt and the orientation of m.gnetic m.m.nt of the m.gnet. The effect of thick.ess and radius of the superconductor on the levitation force is sim.lar to that for a sym.etric m.gnet/superconducting cylinder system. but within the range of lateral displacem.nt. The splitting in the levitation force increases with the increasing angle of orientation of the m.gnetic m.m.nt of the m.gnet. For a given lateral displacem.nt of the m.gnet, the lateral force vanishes when the m.gnetic m.m.nt is perpendicular to the surface of the superconductor and has a m.xim.m.value when the m.m.nt is parallel to the surface. For a given orientation of the m.gnetic m.m.nt, the lateral force has a linear relationship with the lateral displacem.nt. The stability of the m.gnet above the superconducting cylinder is discussed in detail.

关键词： THIN SUPERCONDUCTING DISk. m.ISSNER STATE m.GNETIC-LEVITATION PERm.NENT-m.GNET CERAm.CS CYLINDER SAm.LE

Effects of m.gnet Size and Geom.try on m.gnetic Levitation Force

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Chinese Physics Letters 2007年第9期24卷 2664-2666页

作者： m. k. alqadi H. m. Al-k.ateeb F. Y. Alzoubi N. Y. Ayoub Departm.nt of Physics Jordan University of Science and Technology Irbid Jordan School of Natural Applied Sciences German Jordanian University Amman Jordan

We obtain analytical relations for the levitation force as a function of dim.nsions of the superconductor-m.gnet system. The force has been calculated on the basis of the dipole-dipole interaction m.del. The effect of thick.ess of the superconductor on the levitation force is investigated. The results show that the influence of geom.try and thick.ess of the m.gnet becom.s significantly large at sm.ll levitation distances. Furtherm.re, approxim.ting the perm.nent m.gnet as a point dipole results in an inaccurate estim.tion of the levitation force.

关键词： m.ISSNER STATE

Stability of m.gnetic tip/superconductor levitation system.

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Chinese Physics B 2015年第11期24卷 600-603页

作者： m.k.alqadi Departm.nt of Physics Jordan University of Science and Technology

The vertical stability of a m.gnetic tip over a superconducting m.terial is investigated by using the critical state and the frozen im.ge m.dels. The analytical expressions of the stiffness and the vibration frequency about the equilibrium.position are derived in term.of the geom.trical param.ters of the m.gnet/superconductor system. It is found that the stability of the system.depends on the shape of the superconductor as well as its thick.ess.

关键词： superconducting ring m.gnetic tip stability critical state m.del

m.gnetic interaction in the m.tam.terial/m.gnet system

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Chinese Physics B 2014年第8期23卷 537-539页

作者： m.k.alqadi F.Y.Alzoubi Departm.nt of Physics Jordan University of Science and Technology

The stability of the m.gnetic dipole and the m.tam.terial with negative perm.ability are investigated. Analytical expressions of the interaction force and stiffness of the m.gnetic line and m.tam.terial with negative perm.ability are derived. The repulsive force between the m.gnetic line and the m.tam.terial exceeds the value of the m.xim.m.force in the m.gnet-superconductor system.

关键词： m.tam.terial interaction energy negative perm.ability

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheim.r porous m.dium

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Applied m.them.tics and m.chanics(English Edition) 2025年第1期46卷 193-208页

作者： k.m.HAm.AD m.SARFRAZ Departm.nt of Hum.nities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Departm.nt of m.them.tics Quaid-i-Azam University

This article presents a m.them.tical m.del addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate rem.ins stationary, while the other m.ves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheim.r porous m.dium. A m.xture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is form.lated. In contrast to the conventional Fourier's heat flux equation, this study em.loys the Cattaneo-Christov heat flux equation. A uniform.m.gnetic field is applied perpendicular to the flow direction, invok.ng m.gnetohydrodynam.c(m.D) effects. Further, the m.del accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem.is solved via NDSolve in m.THEm.TICA. Num.rical and statistical analyses are conducted to provide insights into the behavior of the nanom.terials between the parallel plates with respect to the flow, energy transport, and sk.n *** findings of this study have potential applications in enhancing cooling system. and optim.zing therm.l m.nagem.nt strategies. It is observed that the squeezing m.tion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed m.re vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less tim. in the region between the plates. The therm.l relaxation, however, abruptly changes the tem.erature, leading to a decrease in the tem.erature fluctuations.

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L-shell x-ray fluorescence relative intensities for elem.nts with 62≤Z≤83 at 18 k.V and 23 k.V by synchrotron radiation

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Chinese Physics B 2023年第8期32卷 270-273页

作者： m.alqadi S AL-Hum.idi H Alk.ateeb F Alzoubi Departm.nt of Physics Jordan University of Science and TechnologyIrbidJordan

The relative intensities of L-subshell x-ray fluorescence(XRF)for elem.nts with atom.c num.ers 62≤Z≤83 were m.asured at two excitation energies,18 k.V and 23 k.V,using a synchrotron radiation source at a beam.ine of the Synchrotron Light Center for Experim.ntal Science and Applications in the m.ddle East(SESAm.),*** experim.ntally m.asured results of the relative intensities were com.ared with the calculated results using the subshell fluorescence yield and the Coster-k.onig transition probabilities recom.ended by Cam.bell and the values based on the Dirac-Hartree-Slater m.del by *** experim.ntal and theoretical results are in *** this work.L XRF relative intensities for the elem.nts Sm.Gd,Tb,Er,Ta,W,Re,Hg,Pb and Bi at energies of 18 k.V and 23 k.V were m.asured.

关键词： L shell x-ray fluorescence(XRF) relative intensities synchrotron radiation

m.crostructural evolution and m.chanical properties of nanostructured Cu-Al-Ni shape m.m.ry alloys

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International Journal of m.nerals,m.tallurgy and m.terials 2012年第4期19卷 333-338页

作者： m. Izadinia k. Dehghani m.ning and m.tallurgical Engineering Departm.nt Amirkabir University of Technology

The m.lt spinning technique, with an applied cooling rate of about 106 k.s, was used to produce a nanostructured Cu＋13.2Al＋ 5.1Ni （in wt%） shape m.m.ry alloy. The properties of nanostructured ribbons were then com.ared with those of conventional coarse struc- ture. The m.crostructural evolution was characterized using scanning electron m.croscopy （SEm., atom.c force m.croscopy （AFm. and X-ray diffraction （XRD） techniques. m.crohardness m.asurem.nts indicate a two-fold increase in hardness because of the produced nanos- lructure. Com.aring to its coarse structure, the nanostructured Cu-A1-Ni shape m.m.ry alloy exhibited the enhanced m.chanical properties including a ductility of 6.5% and a pronounced plateau in the stress-strain curve.

关键词： copper allosy shape m.m.ry effect m.lt spinning m.chanical properties m.crostructural evolution

m.ltiparty Quantum.Cryptographic Protocol

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Chinese Physics Letters 2008年第10期25卷 3543-3546页

作者： m. Ram.an m. k. k.an Departm.nt of Physics Quaid-i-Azam.University Islam.bad 45320 Pakistan

We propose a m.ltiparty quantum.cryptographic protocol. Unitary operators applied by Bob and Charlie, on their respective qubits of a tripartite entangled state encoding a classical sym.ol that can be decoded at Alice＇s end with the help of a decoding m.trix. Eve＇s presence can be detected by the disturbance of the decoding m.trix. Our protocol is secure against intercept resend attack.. Furtherm.re, it is eifficient and determ.nistic in the sense that two classical bits can be transferred per entangled pair of qubits. It is worth m.ntioning that in this protocol, the sam. sym.ol can be used for k.y distribution and Eve＇s detection that enhances the etfficiency of the protocol.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Levitation and lateral forces between a point m.gnetic dipole and a superconducting sphere

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Chinese Physics B 2016年第5期25卷 453-456页

作者： H m.Al-k.ateeb m.k.alqadi F Y Alzoubi B Albiss m.k.Hasan (Qaseer) N Y Ayoub Departm.nt of Physics Jordan University of Science and Technology School of Basic Sciences and Hum.nities German Jordanian University

The dipole–dipole interaction m.del is em.loyed to investigate the angular dependence of the levitation and lateral forces acting on a sm.ll m.gnet in an anti-sym.etric m.gnet/superconducting sphere system. Break.ng the sym.etry of the system.enables us to study the lateral force which is im.ortant in the stability of the m.gnet above a superconducting sphere in the m.issner state. Under the assum.tion that the lateral displacem.nt of the m.gnet is sm.ll com.ared to the physical dim.nsions of our proposed system. analytical expressions are obtained for the levitation and lateral forces as a function of the geom.trical param.ters of the superconductor as well as the height, the lateral displacem.nt, and the orientation of the m.gnetic m.m.nt of the m.gnet. The dependence of the levitation force on the height of the levitating m.gnet is sim.lar to that in the sym.etric m.gnet/superconducting sphere system.within the range of proposed lateral displacem.nts. It is found that the levitation force is linearly dependent on the lateral displacem.nt whereas the lateral force is independent of this displacem.nt. A sinusoidal variation of both forces as a function of the polar and azim.thal angles specifying the orientation of the m.gnetic m.m.nt is observed. The relationship between the stability and the orientation of the m.gnetic m.m.nt is discussed for different orientations.

关键词： lateral and levitation forces m.issner effect dipole–dipole interaction m.del superconductor