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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.Ikram 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 in the case of ***,it is noted that an empirical 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

Radiative properties of matter based on quantum statistical method

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Chinese Physics B 2017年第7期26卷 234-243页

作者： Rukhsana Kouser G Tasneem muhammad Saleem shahzad S Sardar Amjad Ali m h Nasim m Salahuddin Department of Physics and Applied mathematics Pakistan Institute of Engineering and Applied Sciences hefei National Laboratory for Physical Sciences at microscale and Department of modern Physics University of Science and Technology of China

We present the preliminary results of our code OPAQS（opacity calculation using quantum statistical model） that is based on the self consistent hartree-Fock-Slater model for the average atom. The code is capable of performing robust calculations of average charge state, frequency-dependent and mean opacities. The accuracy of the atomic model is verified by comparing the calculations of average charge state with various published results. The monochromatic opacities for iron computed at different sets of temperatures and densities are compared with LEDCOP. The Rosseland and Planck opacities for iron and aluminum are validated with some state-of-the-art codes. The results are in good agreement with the published data.

关键词： self-consistent average atom model average ionization state Rosseland opacity Planck opacity

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. Streamlines 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

Effect of radiation on compressibility of hot dense sodium and iron plasma using improved screened hydrogenic model with𝑙splitting

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Chinese Physics B 2021年第3期30卷 225-236页

作者： Amjad Ali G Shabbir Naz Rukhsana Kouser Ghazala Tasneem m Saleem shahzad Aman-ur-Rehman m h Nasim Department of Physics and Applied mathematics Pakistan Institute of Engineering and Applied SciencesIslamabad 45650Pakistan Department of Nuclear Engineering Pakistan Institute of Engineering and Applied SciencesIslamabad 45650Pakistan

high pressure investigations of matter involve the study of strong shock wave dynamics within the materials which gives rise to many thermal effects leading to dissociation of molecules,ionization of atoms,and radiation emission,*** response of materials experiencing a strong shock can be determined by its shock hugoniot calculations which are frequently applied in numerical and experimental studies in inertial confinement fusion,laboratory astrophysical plasma,*** studies involve high energy density plasmas in which the radiation plays an important role in determining the energy deposition and maximum compressibility achieved by the shock within *** this study,we present an investigation for the effect of radiation pressure on the maximum compressibility of the material using shock hugoniot *** shock hugoniot calculations,an equation of state(EOS)is developed in which electronic contributions for EOS calculations are taken from an improved screened hydrogenic model with−l splitting(I-ShmL)[high Energy Density Physics(2018)2648]under local thermodynamic equilibrium(LTE)*** thermal ionic part calculations are adopted from the state of the art Cowan model while the cold ionic contributions are adopted from the scaled binding energy *** Shock hugoniot calculations are carried out for sodium and iron plasmas and our calculated results show excellent agreement with published results obtained by using either sophisticated self-consistent models or the first principle study.

关键词： self-consistent-field methods thermodynamics of plasmas average atom model shock hugoniot calculation

Ion population fraction calculations using improved screened hydrogenic model with l-splitting

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Chinese Physics B 2018年第10期27卷 424-432页

作者： Amjad Ali G Shabbir Naz Rukhsana Kouser Ghazala Tasneem m Saleem shahzad Aman-ur-Rehman m h Nasim Department of Physics and Applied mathematics Pakistan Institute of Engineeringand Applied Sciences Department of Nuclear Engineering Pakistan Institute of Engineeringand Applied Sciences

Ion population fraction（IPF） calculations are very important to understand the radiative spectrum emitted from the hot dense matter. IPF calculations require detailed knowledge of all the ions and correlation interactions between the electrons of an ion which are present in a plasma environment. The average atom models, e.g., screened hydrogenic model with l-splitting（ShmL）, now have the capabilities for such calculations and are becoming more popular for in line plasma calculations. In our previous work [Ali A, Shabbir Naz G, shahzad m S, Kouser R, Rehman A and Nasim m h 2018 high Energy Density Phys. 26 48], we have improved the continuum lowering model and included the exchange and correlation effects in ShmL. This study presents the calculation of IPF using classical theory of fluctuation for our improved screened hydrogenic model with l-splitting（I-ShmL） under local thermodynamic equilibrium conditions for iron and aluminum plasma over a wide range of densities and temperatures. We have compared our results with other models and have found a very good agreement among them.

关键词： self-consistent average atom model average ionization state ion population

Fragmentation Cross Sections of 158 AGeV Pb Projectiles

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Chinese Physics Letters 2007年第10期24卷 2800-2803页

作者： G. Sher m.I. shahzad m. hussain Physics Division PINSTECH Islamabad Pakistan Department of Physics University of the Punjab Lahore Pakistan

We investigate the fragmentation cross sections of 158 AGeV ^207Pb projectile interacting with different targets using CR39 nuclear track detectors. The exposure is made at SPS beam facility of CERN. The detectors are chemically etched to obtain data in the form of etched cone length. The nuclear and electromagnetic contributions to the measured total charge-changing cross sections are investigated. The estimated results are compared with those found in the literature for similar research work.

关键词： coated conductor buffer layer self-epitaxy CeO2

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 Iqbal 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 infiltration 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

mass dependence of pion-induced fission cross sections on the level density parameter

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Chinese Physics C 2012年第9期36卷 831-835页

作者： Zafar Yasin Warda Iram m.Ikram shahzad Physics Division PINSTECHP.O.NiloreIslamabadPakistan Physics Department Islamia UniversityBahawalpurPakistan

Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile. In this research work, a cascade-exciton model （using CEm95 computer code） has been implemented to observe the dependence of pion-induced fission cross sections and fission probabilities on the target mass and ratio of the level density parameter in fission to neutron emission. The analysis has been performed for both the positive and negative pions as the projectile at 80, 100 and 150 meV energies. The computed cross sections satisfactorily reproduced the experimental findings when compared with the available experimental data in the literature. We observed a smooth dependence at 150 meV, and a sharper dependence at 80 and 100 meV pion energy, in the fissility region above 29.44.

关键词： CEm95 fission cross section level density parameter