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Cross Section of Heavy ion Reaction （14.5 meV/u） ^132Xe ＋ Bi

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Chinese Physics Letters 2006年第3期23卷 572-575页

作者： G. Sher m.i. shahzad m. Hussain m. A. Rana E. U. Khan Physics Research Division PINSTECH P.O Nilore Islamabad Pakistan Department of Physics University of the Punjab Lahore Pakistan

We investigate the cross section of the heavy ion reaction （14.5 meV/u） ^132Xe ＋ Bi by using a CR-39 plastic track detector. The target-detector assembly is exposed at UNiLAC beam facility of GSi, Germany. After etching under appropriate etching conditions, the detector is scanned for multipronged events produced as a result of interactions of projectile ions with target atoms. The elastic events are separated from binary events and used for the determination of the quarter-point angle. The quarter-point angle obtained is used to determine the total reaction cross section. The total experimental reaction cross section is determined by using statistics of inelastic events of two-pronged and higher multiplicity events. The experimental reaction cross sections determined by using elastic and inelastic data observed in the reaction under study are found to be in good agreement with the theoretically calculated value of reaction cross section using a sharp cutoff model.

关键词： SEQUENTiAL FiSSiON COULOmB BARRiER TRACK DETECTORS NUCLEAR SCATTERiNG PB-208

Fission of Weakly Prolate 119Sn and Weakly Oblate ^(209)Bi Nuclei induced by 500 and 672 meV Negative Pions

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Chinese Physics Letters 2011年第9期28卷 88-91页

作者： mukhtar Ahmed Rana Gul Sher Shahid manzoor m.i.shahzad Physics Division Pakistan Institute of Nuclear Science and Technology(PINSTECH)P.O.NiloreIslamabadPakistan

Fission cross-sections of ^(119)Sn and ^(209)Bi induced by negative pions of two energies 500 and 672 meV were measured using a CR−39 nuclear track ***-detector stacks were exposed to pion beams at the Brookhaven National Laboratory(USA).measurement results are compared with the corresponding calculations using the computer code *** between measurements and calculations is fairly good for the ^(209)Bi target nuclei whereas it is poor for 119Sn at both investigated energies of 500 and 672 *** cross−section results of^( 119)Sn and ^(209)Bi are explained using the equilibrium properties of these nuclides including nuclear electric quadrupole moments which determine the shapes of nuclei.A logarithmic dependence of fission cross−section on Z^(2)/A is observed for the above−mentioned reactions and a critical limit of Z^(2)/A is identified with the value of 30 which divides the curve ofσf versus Z2/A into two regimes,one with weak dependence and the other with strong dependence.

关键词： Weakly mentioned limit

Comparison of Fission induced by Protons and Pions

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Chinese Physics Letters 2011年第8期28卷 58-60页

作者： Zafar Yasin m.i.ram shahzad Physics Division PINSTECHP.O.NiloreIslamabadPakistan

We compare the properties of fission induced by protons and *** different methodologies are used to make this ***,it is shown that pion-induced fission cross sections are not much different in magnitude from proton-induced fission cross sections at the same beam kinetic ***,across the pion-nucleon(3,3)resonance so prominent with free nucleons,it has been observed that there is no significant change in the reaction mechanism.i. the case of ***,it is noted that an em.i.ical expression used for evaluations of proton-induced fission cross sections is also valid for positive pion-induced fission cross sections,at least for actinide *** cross sections computed using a cascade-exciton model code for ^(209)Bi and ^(238)U are also compared with the experimental data available.

关键词： energy beam kinetic

Negative Pion induced Fission with Heavy Target Nuclei

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Chinese Physics Letters 2011年第1期28卷 58-61页

作者： O. Sher mukhtar A. Rana S. manzoor m. i. shahzad Physics Division PINSTECH P.O. Nilore Islamabad Pakistan

We investigate fission induced by negative pions in copper and bismuth targets using CR-39 dielectric track detectors. The target-detector assemblies in 4π-geometric configuration were exposed at the AGS facility of Brookhaven National Laboratory, USA. The exposed detectors were chemically etched under appropriate etching conditions and scanned to collect data in the form of fission fragments tracks produced as a result of interaction of pions with the target nuclei. Using the track counts, the experimental fission cross sections for copper and bismuth have been measured at energies of 500, 672, 1068 and 1665 meV and compared with the calculation using the Cascade-Exciton model code （CEm95）. The values of fission probability based on experimental fission cross-sections have been compared with the theoretically calculated values of fission probabilities obtained using the CEm95 code. Good agreement is observed between the measured and computed results.

关键词： Nuclear physics

Generalized Ⅰ-Nonexpansive Selfmaps and invariant Approximations

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Acta mathematica Sinica,English Series 2008年第5期24卷 867-876页

作者： m.A.AL-THAGAFi Naseer shahzad Department of mathematics King AbduIAziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

Common fixed point results for new classes of noncommuting selfmaps satisfying generalized i-contraction or i-nonexpansive type conditions are established. We apply them to obtain several invariant approximation resul... 详细信息

关键词： common fixed point occasionally weakly compatible map ultraoccasionally weakly compatible map generalized i-nonexpansive map invariant approximation

Hydrodynamics of viscous fluid through porous slit with linear absorption

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Applied mathematics and mechanics(English Edition) 2016年第3期37卷 361-378页

作者： A.m.SiDDiQUi T.HAROON A.shahzad Department of mathematics Pennsylvania State UniversityYork Campus Department of mathematics COMSATS Institute of Information Technology

The exact solutions for the viscous fluid through a porous slit with linear ab- sorption are obtained. The Stokes equation with non-homogeneous boundary conditions is solved to get the expressions for the velocity components, pressure distribution, wall shear stress, fractional absorption, and leakage flux. The volume flow rate and mean flow rate are found to be useful in obtaining a convenient form of the longitudinal velocity component and pressure difference. The points of the maximum velocity components for a fixed axial distance are identified. The value of the linear absorption parameter is ran- domly chosen, and the rest available data of the rat kidney to the tabulate pressure drop and fractional absorption are incorporated. The effects of the linear absorption, uniform absorption, and flow rate parameters on the flow properties are discussed by graphs. it is found that forward flow occurs only if the volume flux per unit width is greater than the absorption velocity throughout the length of the slit, otherwise back flow may occur. The leakage flux increases with the increase in the linear absorption parameter. Stream.i.es are drawn to help the analysis of the flow behaviors during the absorption of the fluid flow through the renal tubule and purification of blood through an artificial kidney.

关键词： exact solution porous slit linear absorption renal tubule

FiXED POiNT THEOREmS AND BEST APPROXimATiON iN CONVEX mETRiC SPACES

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Analysis in Theory and Applications 1992年第4期8卷 97-105页

作者： i.Beg N.shahzad m.i.bal Quaid-i-Azam University Pakistan

Results regarding best approximation and best Simultaneous approximation on convex metric spaces are *** of fixed points for an ultimately nonexpansive semigroup of mappings is also shown.

关键词： CiG FiXED POiNT THEOREmS AND BEST APPROXimATiON iN CONVEX mETRiC SPACES

mass Transfer： a Deciding Factor for the multiplicity of an Event in Deep inelastic Collisions

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Chinese Physics Letters 2006年第10期23卷 2714-2716页

作者： Tabassum Nasir J.J.Baluch E.U.Khan F.N.Khattak m.i.shahzad Department of Physics Gomal University D.I. Khan Pakistan Department of Physics CIIT Islamabad Pakistan U.W.C. Gomal UniversityD.I.KhanPakistan physics Research Division PINSTECH Islamabad Pakistan

intermediate stage of the three and four-pronged events is investigated in the reaction ^208Pb＋^197Au at beam energy 11.67 meV/u. multiprong events are analysed numerically using an em.i.ical mass-dependent velocityrauge relation. Using the measured three-dimensional coordinates of correlated tracks, it is possible to determine the quantities such as mass transfer and total kinetic energy loss. These quantities are then used to study the intermediate stage of the reaction. it has been observed that mass transfer and total kinetic energy loss at the first step of the reaction decides the multiplicity of an event at the second stage of the sequential fission process.

关键词： HEAVY-iON iNTERACTiON miCA TRACK DETECTORS CHANNELS FiSSiON U-238

Theoretical study of reactive melt infiltration to fabricate Co-Si/C composites

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Chinese Physics B 2021年第11期30卷 434-439页

作者： Saqib shahzad Khurram.i.bal Zaheer Uddin Department of Physics University of KarachiKarachiSindh 75270Pakistan College of Computer Science and information Systems Institute of Business Management(IoBM)KarachiSindh 75190Pakistan

Cobalt-silicon based carbon composites(Co–Si/C)have established a noteworthy consideration in recent years as a replacement for conventional materials in the automotive and aerospace *** achieve the composite,a reactive melt infiltration process(Rmi)is used,in which a melt impregnates a porous preform by capillary *** method promises a high-volume fraction of reinforcement and can be steered in such a way to get the good“near-net”shaped components.A mathematical model is developed using reaction-formed Co–Si alloy/C composite as a prototype system for this *** wetting behavior and contact angle are discussed;surface tension and viscosity are calculated by Wang’s and Egry’s equations,*** radii of 5μm and 10μm are set as a reference on highly oriented pyrolytic *** graphs are plotted using the model,to study some aspects of the infiltration *** highlights the possible connections among the various *** this attempt,the Co–Si(62.5 at.%silicon)alloy’s maximum.i.filtration at 5μm and 10μm radii are found as 0.05668 m at 125 s and 0.22674 m at 250 s,respectively.

关键词： cobalt-silicon/carbon composites Co-Si alloy reactive melt infiltration(Rmi) carbon preforms