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Dip Coating of Nano Hydroxyapatite on Titanium Alloy with Plasma Assistedγ-Alumina Buffer Layer:A Novel Coating Approach

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Journal of materials Science & Technology 2013年第6期29卷 557-564页

作者： m.khalid m.mujahid A.Nusair khan R.S.Rawat School of Chemical and materials Engineering National University of Sciences and TechnologySector H-12IslamabadPakistan Institute of Industrial Control Systems RawalpindiPakistan NSSE National Institute of EducationNanyang Technological UniversitySingapore

This paper reported a novel coating approach to deposit a （HA） film on Ti6Al4V alloy with Al2O3 buffer layer for thin, crack free and nano-structured hydroxyapatite biomedical implants. The Al2O3 buffer layer was deposited by plasma spraying while the HA top layer was applied by dip coating technique. The X-ray diffraction （XRD） and Raman reflections of alumina buffer layer showed α- to γ-Al2O3 phase transformation; and the fractographic analysis of the sample revealed the formation of columnar grains in well melted splats. The bonding strength between Al2O3 coating and Ti6Al4V substrate was estimated to be about 40 mPa. The presence of dip coated HA layer was confirmed using XRD, scanning electron microscopy （SEm） and energy dispersive X-ray spectroscopy （EDX） analysis. The SEm images exhibited that HA top layer enveloped homogenously the troughs and crests of the underneath rough （Ra = 2.91 μm） Al2O3 surface. It is believed that the novel coating approach adopted might render the implant suitable for rapid cement-less fixation as well as biocompatible for longer periods.

关键词： Ti6Al4V alloy Biomaterials Buffer layer Ceramic coatings

Effect　of　Ballistic-Type　Hot　Atom　Adsorption　mechanism　on　the　Phase　Diagram　of　monomer　Dimer　CO-O2　Surface　Catalytic　Reaction：　A　monte　Carlo　Simulation

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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： m.khalid K.m.khan A.U.Qaisrani Q.N.malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan NuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

Phase Diagram Body-Centredof Catalytic Oxidation of CO on the Surface-Subsurface of a Body-Centred Cubic Structure with Eley-Rideal Process： A monte Carlo Simulation

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Chinese Physics Letters 2004年第9期21卷 1838-1841页

作者： AU.Qaisrani m.khalid musaKaleemBalocht DepartmentofPhysics GomalUniversityD.I.KhanPakistan DepartmentofChemistry GomalUniversityD.I.KhanPakistan

monte Carlo simulation is used to explore the effects of the Eley-Rideal (ER) process on the phase diagram of the Langmuir–Hinshelwood (LH) type monomer–dimer (CO–O2) catalytic reaction on the surface and subsurface of a body-centred cubic structure, which extends to only two layers in the z-direction. The dimer (O2) is adsorbed in such a way that it takes one surface site whereas the second site is from the subsurface. For this mechanism, an interesting situation develops. The production rate of CO2 is found to be consistent with experiment. The qualitative trend of the surface oxygen coverage is not consistent with the experimental situation in one model while it is found to be consistent with that in another model, i.e. the coverage of surface oxygen decreases slowly with increase of concentration of CO (yCO). moreover, the production of CO2 can be predicted in the form of a mathematical relation.

关键词： Phase diagrams

Non-Thermal Effects on CO-NO Surface Catalytic Reaction on Square Surface： monte Carlo Study

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Chinese Physics Letters 2005年第6期22卷 1533-1535页

作者： m.khalid A.U.Qaisrani W.Ahmad DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan PhysicsResearchDivision PakistanInstituteofNuclearScienceandTechnologyPONiloreIslamabadPakistan

A monte Carlo simulation of the CO–NO heterogeneous catalytic reaction over a square surface has already been studied with a model based on the Langmuir–Hinshelwood (LH) mechanism. The results of this study are well known. Here we study the effects of transient non-thermal mobility of monomer (CO) based on precursor mechanism, diffusion of adsorbed nitrogen and oxygen atoms, on the phase diagram. The interesting feature of this model is the yield of a steady reactive window, while simple LH mechanism is not capable of producing a steady reactive state.

关键词： FOPT SOPT CO ZGB

Optimization Study of Pulsed DC Nitrogen-Hydrogen Plasma in the Presence of an Active Screen Cage

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Plasma Science and Technology 2014年第5期16卷 460-464页

作者： A.SAEED A.W.khan F.JAN H.U.SHAH m.ABRAR m.ZAKA-UI-ISLAm m.khalid m.ZAKAULLAH National Centre for Physics Quaid-i-Azam University Campus Islamabad Department of Physics Gomal University Department of Physics Quaid-i-Azam University Department of Physics Hazara University Mansehra Department of Physics Faculty of ScienceUniversity of Jazan

A glow discharge plasma nitriding reactor in the presence of an active screen cage is optimized in terms of current density,filling pressure and hydrogen concentrations using optical emission spectroscopy（OES）.The samples of AISI 304 are nitrided for different treatment times under optimum *** treated samples were analyzed by X-ray diffraction（XRD） to explore the changes induced in the crystallographic *** XRD pattern confirmed the formation of iron and chromium nitrides arising from incorporation of nitrogen as an interstitial solid solution in the iron lattice.A Vickers microhardness tester was used to evaluate the surface hardness as a function of treatment time（h）.The results showed clear evidence of improved surface hardness and a substantial amount of decrease in the treatment time compared with the previous work.

关键词： optical diagnostics plasma nitriding austenitic stainless steel

Decoherence Effects on multiplayer Cooperative Quantum Games

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Communications in Theoretical Physics 2011年第8期56卷 228-234页

作者： Salman khan m.Ramzan m.khalid.khan Department of Physics Quaid-i-Azam University

We study the behavior of cooperative multiplayer quantum games [Q. Chen, Y. Wang, J.T. Liu, and K.L. Wang, Phys. Lett. A 327 （2004） 98; A.P. Flitney and L.C.L. Hollenberg, Quantum Inf. Comput. 7 （2007） 111] in the presence of decoherence using different quantum channels such as amplitude damping, depolarizing and phase damping. It is seen that the outcomes of the games for the two damping channels with maximum values of decoherence reduce to same value. However, in comparison to phase damping channel, the payoffs of cooperators are strongly damped under the influence amplitude damping channel for the lower values of decoherence parameter. In the case of depolarizing channel, the game is a no-payoff game irrespective of the degree of entanglement in the initial state for the larger values of decoherence parameter. The deeoherenee gets the cooperators worse off.

关键词： multiplayer cooperative quantum games payoffs Nash equilibria

Electrical, Thermal, Photocatalytic and Antibacterial Studies of metallic Oxide Nanocomposite Doped Polyaniline

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Journal of materials Science & Technology 2013年第9期29卷 795-800页

作者： Saima Sultana Rafuddin mohammad Zain khan khalid Umar m.muneer membrane Research Laboratory Department of Chemistry Faculty of Science Aligarh Muslim University Department of Civil Environmental and Geomatic Engineering Chadwick Building University College London Environmental Research Laboratory Department of Chemistry Faculty of Science Aligarh Muslim University

ZnO-ZrO2 nanocomposite was prepared by sol-gel method and in-situ polymerization was used to synthesize ZnO-ZrO2 nanocomposite doped polyaniline （PANI）. The materials were characterized by X-ray diffraction （XRD）, Fourier transform infrared （FTIR） spectroscopy, transmission electron microscopy （TEm）, scanning electron microscopy （SEm） and energy dispersive X-ray spectroscopy （EDX） to ensure the crystallite size, functional groups, morphology and chemical composition of the polymer nanocomposite complex. The average particle size of the ZnO-Zr02 nanoparticles was found to be 20.5 nm. Thermal gravimetric analysis （TGA） was used to study the thermal stability of the complex, shows improved thermal stability of polymer nanocomposite as compared to the pure organic polymer. The material also possesses good electrical conductivity. Additionally, the photocatalytic activity of the materials was investigated by monitoring the decolorization of Acid Blue 29 dye in a UV photocatalytic reactor and PANI-ZnO-ZrO2 was found to possess higher photocatalytic activity than pure PANI. Finally, the antibacterial activity of the materials was examined and it was observed that PANI-ZnO-ZrO2 could be used as an excellent antibacterial agent. Hence, desired properties could be integrated by mixing appropriate phases of the materials for specific applications such as heterogeneous catalyst, antibacterial agents, antibiotics delivery and high temperature conducting polymers.

关键词： Nanocomposites Polyaniline Electrical conductivity Photocatalyst Antibacterial agents

Effect of Precursor mechanism on CO-NO Catalytic Reaction on Body-Centred Cubic Structure： monte Carlo Simulation

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Chinese Physics Letters 2005年第9期22卷 2422-2425页

作者： A. U. Qaisrani m. khalid m. K. khan Department of Physics Gomal University Dera Ismail Khan Pakistan Department of Physics Quaid-i-Azam University Islamabad Pakistan

The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by monte Carlo simulation. The simple Langmuir-Hinshelwood （LH） mechanism yields a steady reactive window, which is separated by continuous and discontinuous irreversible phase transitions. The effect of precursor mechanism on the phase diagram of the system is also studied. According to this mechanism, the precursor motion of CO molecules is considered only on the surface of bcc lattice. Some interesting observations are reported.

关键词： KINETIC PHASE-TRANSITIONS SURFACE-REACTION mODEL SUBSURFACE OXYGEN HEXAGONAL SURFACES SQUARE LATTICE REDUCTION PLATINUm PT(100) O-2

Recent progress and challenges in silicon-based anode materials for lithium-ion batteries

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Industrial Chemistry & Materials

Industrial Chemistry & materials 2024年第2期2卷 226-269页

作者： Gazi Farhan Ishraque Toki m.khalid Hossain Waheed Ur Rehman Rana Zafar Abbas manj Li Wang Jianping Yang State Key Laboratory for modification of Chemical Fibers and Polymer materials College of Materials Science and EngineeringDonghua UniversityShanghaiChina Institute of Electronics Atomic Energy Research EstablishmentBangladesh Atomic Energy CommissionDhaka 1349Bangladesh

Anode materials for Li-ion batteries(LIBs)utilized in electric vehicles,portable electronics,and other devices are mainly graphite(Gr)and its ***,the limited energy density of Gr-based anodes promotes the exploration of alternative anode materials such as silicon(Si)-based materials because of their abundance in nature and low ***,Si can store 10 times more energy than Gr and also has the potential to enhance the energy density of *** the many advantages of Si-based anodes,such as high theoretical capacity and low price,their widespread use is hindered by two major issues:charge-induced volume expansion and unreliable solid electrolyte interphase(SEI)*** this detailed review,we highlight the key issues,current advances,and prospects in the rational design of Si-based electrodes for practical *** first explain the fundamental electrochemistry of Si and the importance of Si-based anodes in *** excessive volume increase,relatively low charge efficiency,and inadequate areal capacity of Si-based anodes are discussed to identify the barriers in enhancing their performance in ***,the use of binders(e.g.,linear polymer binders,branched polymer binders,cross-linked polymer binders,and conjugated conductive polymer binders),material-based anode composites(such as carbon and its derivatives,metal oxides,and mXenes),and liquid electrolyte construction techniques are highlighted to overcome the identified ***,tailoring Si-based materials and reshaping their surfaces and interfaces,including improving binders and electrolytes,are shown to be viable approaches to address their drawbacks,such as volume expansion,low charge efficiency,and poor areal ***,we highlight that research and development on Si-based anodes are indispensable for their use in commercial applications.

关键词： Lithium-ion battery Silicon-based anode Volume expansion Solid electrolyte interphase propagation Binders Composite anode materials