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Preparation and Properties of Evaporated CdTe and All Thin Film CdTe/CdS Solar Cells

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Chinese Physics Letters 1991年第5期8卷 255-258页

作者： shahzad Naseem Centre for Solid State Physics University of the PunjabQuaid-e-Azam CampusLahore(PAKISTAN)

Cadmium telluride thin films were prepared by vacuum evaporation of CdTe powder in an attempt to fabricate all thin film solar cells of the type CdTe/*** of CdTe has shown it to have a band gap of 1.522eV and a resistivity of 22Ω-*** prepared,solar cells exhibited low values of output *** quantity of copper was then deposited on top of the CdTe/CdS solar cells and the whole system was annealed at 350℃.This copper doping changed the output parameters favorably with a maximum efficiency of 1.9%.

关键词： CdTe/CdS CdTe copper

Hypersonic reentry trajectory planning by using hybrid fractional-order particle swarm optimization and gravitational search algorithm

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Chinese Journal of Aeronautics 2021年第1期34卷 50-67页

作者： Khurram shahzad SANA Weiduo HU School of Astronautics Beihang UniversityBeijing 102206China

This paper proposes a novel hybrid algorithm called Fractional-order Particle Swarm optimization Gravitational Search Algorithm(FPSOGSA)and applies it to the trajectory planning of the hypersonic lifting reentry flight *** proposed method is used to calculate the control profiles to achieve the two objectives,namely a smoother trajectory and enforcement of the path constraints with terminal *** smoothness of the trajectory is achieved by scheduling the bank angle with the aid of a modified scheme known as a Quasi-Equilibrium Glide(QEG)*** aerodynamic load factor and the dynamic pressure path constraints are enforced by further planning of the bank angle with the help of a constraint enforcement *** maximum heating rate path constraint is enforced through the angle of attack *** Common Aero Vehicle(CAV)flight vehicle is used for the simulation purpose to test and compare the proposed method with that of the standard Particle Swarm Optimization(PSO)method and the standard Gravitational Search Algorithm(GSA).The simulation results confirm the efficiency of the proposed FPSOGSA method over the standard PSO and the GSA methods by showing its better convergence and computation efficiency.

关键词： Fractional-order Gravitational search algorithm Particle swarm optimization Reentry gliding vehicle Trajectory optimization

Elastic-viscoplastic constitutive model for capturing the mechanical response of polymer composite at various strain rates

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Journal of Materials Science & Technology 2020年第22期54卷 12-17页

作者： shahzad Fateh Ali Jitang Fan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing700087China

Recently, polymer composites, consisting of hard segments and soft segments blend, attract a broad research interest because of the high flow stress and large deformation under a high rate loading. They display an outstanding energy absorption capability for impact resistant engineering. In this paper,a physics-based elastic-viscoplastic constitutive model is developed which accounts the activation of molecular chains motion at different segments upon an applied stress as well as the rate dependency of mechanical properties. Accordingly, finite element simulations are conducted to derive the mechanical performance at various strain rates. It involves the linearly elastic deformation to yielding, softening behavior with a slight decrease of stress, plastic flow at a plateau stress accompanied by a considerable straining, densification with a fast increase of stress. The results achieved from model simulations match well with these obtained by experiments and the mechanical response in the strain rate range from 0.0001 s^(-1) to 8000 s^(-1) can be captured by this model. Finally, energy absorption capability of the polymer composite is discussed, and the physical mechanisms in material science are addressed by post-loading analysis. This work is full of interest to develop the constitutive model for designing the impact-resistant polymers and illustrating the dynamic mechanical response, which will promote the application of light-weight transparent protection structure against a high-speed impact.

关键词： Polymer composite Constitutive model Strain rate Mechanical behavior

An approach to Iocational marginal price based zonal congestion management in deregulated electricity market

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Frontiers in Energy 2016年第2期10卷 240-248页

作者： Md SARWAR Anwar shahzad SIDDIQUI Department of Electrical Engineering Jamia Millia Islamia (A Central University) New Delhi 110025 India

Congestion of transmission line is a vital issue and its management pose a technical challenge in power system deregulation. Congestion occurs in deregulated electricity market when transmission capacity is not sufficient to simultaneously accommodate all constraints of power transmission through a line. Therefore, to manage congestion, a locational marginal price （LMP） based zonal congestion management approach in a deregulated elec- tricity market has been proposed in this paper. As LMP is an economic indicator and its difference between two buses across a transmission line provides the measure of the degree of congestion, therefore, it is efficiently and reliably used in deregulated electricity market for conges- tion management. This paper utilizes the difference of LMP across a transmission line to categorize various congestion zones in the system. After the identification of congestion zones, distributed generation is optimally placed in most congestion sensitive zones using LMP difference in order to manage congestion. The performance of the proposed methodology has been tested on the IEEE 14-bus system and IEEE 57-bus system.

关键词： locational marginal price (LMP) distributed generation pool market deregulated electricity market,congestion management

Thermodynamic Characteristics of Dusty Plasma Studied by Using Molecular Dynamics Simulation

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Plasma Science and Technology 2012年第9期14卷 771-777页

作者： Aamir shahzad 何茂刚 Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education(MOE) Xi'an Jiaotong University Department of Physics Government College University Faisalabad(GCUF)Allama Iqbal RoadFaisalabad 38000Pakistan

Thermodynamic properties of a Debye-Yukawa system of particles are explored by using molecular dynamics simulation in the canonical ensemble. The excess free energy f of the Debye-Yukawa system is calculated by using two different approaches for the liquid phase, and the energy is obtained in a coupling parameter range of 0 ≤ F ≤100 and a wide range of the screening parameter κ. Simulation measurements for excess internal energy and pressure of the system over dimensionless parameters （κ, F） are also presented and compared with previous theoretical and simulated results. A F-expansion-fitting approach for the liquid phase is introduced with the expansion coefficients, which are functions of the screening parameter κ. The fitting coefficients are obtained by directly comparing them with the simulation measurements with a relative deviation of 1% or less. It is shown that the computational results provide a relatively simple method to calculate the excess internal energy and free energy in certain cases, which depend strongly on Г.

关键词： Debye-Yukawa system thermodynamic properties molecular dynamics free energy

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

Morphology and ontogeny of directly differentiating shoot buds and somatic embryos in Santalum album L.

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Journal of Forestry Research 2019年第4期30卷 1179-1189页

作者： Rakhshanda Akhtar Anwar shahzad Plant Biotechnology Section Department of BotanyAligarh Muslim University

Santalum album *** a commercially important tree that yields essential oil of high medicinal *** research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,*** differences between the structures were confirmed using scanning electron microscopy and histological *** medium containing 6-benzyladenine or BA(2.5μM)produced highest number of direct SB,while MS+BA(7.5μM)proved suitable for higher frequency of SE *** differentiating structures attained growth when transferred to MS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis.

关键词： Direct somatic embryos Emblings Histology Hypocotyl Ontogenic

Viscosity Approximation Methods for Nonexpansive Multimaps in Banach Spaces

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Acta Mathematica Sinica,English Series 2010年第6期26卷 1165-1176页

作者： Habtu ZEGEYE Naseer shahzad Bahir Dar University Department of Mathematics King Abdul Aziz University

We prove strong convergence of the viscosity approximation process for nonexpansive nonself multimaps. Furthermore, an explicit iteration process which converges strongly to a fixed point of multimap T is constructed.... 详细信息

关键词： nonexpansive retract Banach spaces fixed point inwardness nonexpansive multimap

Effect of Reaction Temperature and Time on the Structural Properties of Cu(In,Ga)Se_2 Thin Films Deposited by Sequential Elemental Layer Technique

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Journal of Materials Science & Technology 2007年第4期23卷 499-503页

作者： Saira RIAZ shahzad NASEEM Centre for Solid State Physics University of the Punjab QACLahore-54590Pakistan

Thin films of copper indium gallium selenide Cu（In,Ga）Se2 （CIGS） were prepared by sequential elemental layer deposition in vacuum at room temperature. The as-deposited films were heated in vacuum for compound formation, and were studied at temperature as high as 1250℃ for the first time. These films were concurrently studied for their structural properties by X-ray diffraction （XRD） technique. The XRD analyses include phase transition studies, grain size variation and microstrain measurements with the reaction temperature and *** has been observed that there are three distinct regions of variation in all these parameters. These regions belong to three temperature regimes：〈450℃, 450-950℃, and 〉950℃. It is also seen that the compound formation starts at 250℃, with ternary phases appearing at 350℃ or above. Whereas, there is another phase shift at 950℃ without any preference to the quaternary compound.

关键词： Cu(In,Ga)Se2 (CIGS) X-ray Diffraction Thin films Structural analysis