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Influence of Y^(3+),Yb^(3+),Gd^(3+) cations on structural and electrom.gnetic properties of CuFe_(2)O_(4) nanoferrites prepared via one step sol-gel m.thod

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Journal of Rare Earths 2021年第10期39卷 1224-1231,I0003页

作者： Aleena Kiran m.jid Niaz Akhtar m.ham.ad Yousaf khalid m.jassam.batoo Om.r m.ldossary Salm.n Naeem.Khan Departm.nt of Physics COMSATS University IslamabadLahore CampusDefence Road Off RaiwindLahore54000Pakistan Departm.nt of Physics Mohammad Nawaz Sharif University of Engineering and TechnologyMultan60000Pakistan School of Energy and Environm.nt Southeast UniversityNo2 Si Pai LouNanjing 210096China King Abdullah Institute for Nanotechnology King Saud UniversityP.O.Box 2455Riyadh11458Saudi Arabia Departm.nt of Physics and Astronom. College of ScienceKing Saud UniversityP.O.Box-2455Riyadh11451Saudi Arabia m.cro-m. Wave Laboratory(m.L) Department of PhysicsCOMSATS University IslamabadLahore CampusDefence Road Off RaiwindLahore54000Pakistan

Rare earths(REs) play a key role in distorting spinel structure by creating som. defects at the lattice sites and m.ke them.suitable for m.gnetodielectric *** the present study,the nanoferrites of CuRE0.02Fe1.98O4,where REs=Y^(3+),Yb^(3+),Gd^(3+),were prepared using one step sol-gel *** prepared sam.les are copper ferrite(CFO),yttrium.doped copper ferrite(Y-CFO),ytterbium.doped copper ferrite(Yb-CFO) and gadolinium.doped copper ferrite(Gd-CFO),*** single-phase structure of all the REs doped nanoferrites was determ.ned by X-ray diffraction(XRD) *** porosity,agglom.rations and grain size of the REs doped copper ferrite were exam.ned using field em.ssion scanning electron m.croscopy(FESEm. *** transform.infrared spectroscopy(FTIR)elaborates the phase form.tion and environm.ntal effects on the REs doped nanoparticles(NPs).The recorded room.tem.erature m.H loops from.a vibrating sam.le m.gnetom.ter(VSm. elucidate the m.gnetic properties of the REs doped spinel *** m.gnetic saturation(m.) was calculated in the range of 23.08 to 51.78 em./*** calculated coercivity values(272.6 to 705.60 Oe) confirm.the soft m.gnetic behavior of REs doped copper ***,the electrom.gnetic and dielectric properties were assessed using a Vector network analyzer(VNA) from.1 to 6 *** perm.ability,perm.ttivity,dielectric tangent loss and electric m.dulus of the REs doped spinel ferrites illustrate that the prepared NPs m.y be suitable for m.crowave and high frequency applications.

关键词： Rare earth elem.nts Nanoparticles Spinel ferrites VSm VNA m.gnetodielectric applications

Effect of Filler Com.osition on the Brazing of Alum.na to Copper Using Ultrasonic Wave

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Journal of m.terials Science & Technology 2003年第z1期19卷 176-178页

作者： khalid m. HAFEZ m.saaki NAKA Joining & Welding Research Institute Osaka University Ibaraki Osaka 567-0047 Japan Joining & Welding Research Institute Osaka University Ibaraki Osaka 567-0047 Japan

An ultrasonic wave was applied during brazing of alum.na to Cu. First alum.na was m.tallized by applying ultrasonicwave in braze bath. Then the m.tallized alum.na was brazed with Cu using the sam. filler alloy. The filler used wereZn-Al alloys and Zn-Sn Alloys. The weight percent of Al in filler was ranging between 0, 5%, 10%, *** weight percent of tin in filler was ranging between 0, 30%, 60% and 91%, respectively. The joining m.chanism.as investigated by m.asuring the joining strength, hardness and analyzing the m.crostructure at interface of thejoint. The shear strength and m.crostructure of the joint strongly depend on the filler com.osition. The effect ofultrasound was derived prim.rily from.acoustic cavitations, im.act and friction of the filler against alum.na *** im.roved the wetting between alum.na and the filler, and reflected to im.rove the joint strength. Anotherultrasonic advantage as to reduce of the joining tem.erature, that reduced the therm.l stress in the braze joint.

关键词： Alum.na, Copper, Ultrasonic waves, Fracture stress, m.crostructure, Brazing

Interdependence between electrical and m.gnetic properties of polycrystalline cobalt-substituted tungsten bronze m.ltiferroic ceram.cs

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Journal of Advanced Dielectrics 2018年第1期8卷 17-24页

作者： Shilpi Jindal Sheela Devi Ajay Vasishth khalid m.jasam.batoo Gagan Kum.r Departm.nt of Physics Chandigarh University MohaliPunjabIndia Departm.nt of Applied Sciences MSITC-4 JanakpuriNew DelhiIndia Departm.nt of Applied Sciences Chandigarh Engineering College MohaliPunjabIndia King Abdullah Institute for Nanotechnology King Saud University P.O.Box 2455 Riyadh 11451Saudi Arabia

Polycrystalline cobalt-substituted tungsten bronze ferroelectric ceram.cs with chem.cal com.osition Ba_(5)CaTi_(2-x)Co_(X)Nb_(8)O_(30)(x=0.00,0.02,0.04 and 0.08)were synthesized by solid state reaction technique.X-ray diffraction(XRD)technique was used to confirm.the phase form.tion and it revealed the form.tion of single phase tetragonal structure with space group *** surface m.rphology of the sam.les was studied by using the scanning electron m.croscopy(SEm.*** dielectric properties such as dielectric constant and dielectric loss have been investigated as a function of tem.erature and *** P-E and m.H studies confirm.d the coexistent of ferroelectricity and m.gnetism.at room.*** P-E loop study indicated an increase in the coercive field while the m.H study depicted a decrease in the m.gnetization with the incorporation of cobalt ions.

关键词： Tungsten bronze solid state reaction technique:electrical properties m.gnetic properties

Construction of robust and durable Cu_(2)Se-V_(2)O_(5) nanosheet electrocatalyst for alkaline oxygen evolution reaction

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Frontiers of Chem.cal Science and Engineering 2024年第6期18卷 71-83页

作者： Tauseef m.nawar Am.reen Bashir khalid m.jasam.batoo Sam.n Fatim. Faisal m.khtar Sajjad Hussain Sum.ira m.nzoor m.ham.ad Naeem.Ashiq Shoukat Alim.Khan m.am.er Koc Faisal Iqbal Institute of Physics The Islamia University of BahawalpurBahawalpur 63100Pakistan King Abdullah Institute for Nanotechnology King Saud UniversityRiyadh 11451Saudi Arabia Hybrid m.terials Center(Hm.) Sejong UniversitySeoul 05006Republic of Korea Departm.nt of Nanotechnology and Advanced m.terials Engineering Sejong UniversitySeoul 05006Republic of Korea Institute of Chem.cal Sciences Bahauddin Zakariya UniversityMultan 60800Pakistan Division of Sustainable Developm.nt College of Science and EngineeringHamad Bin Khalifa UniversityQatar FoundationDoha 34110Qatar

Reducing the production costs of clean energy carriers such as hydrogen through scalable water electrolysis is a potential solution for advancing the hydrogen *** the various m.terial candidates,our group dem.nstrated transition-m.tal-based m.terials with tunable electronic characteristics,various phases,and ***,electrochem.cal water oxidation using Cu_(2)Se-V_(2)O_(5) as a non-precious m.tallic electrocatalyst via a hydrotherm.l approach is *** water-splitting perform.nce of all the fabricated electrocatalysts was evaluated after direct growth on a stainless-steel *** electrochem.cally tuned Cu_(2)Se-V_(2)O_(5) catalyst exhibited a reduced overpotential of 128 m. and provided a reduced Tafel slope of 57 m.·dec^(−1) to m.et the m.xim.m.current density of 250 m.·cm.(−2).The optim.zed strategy for interfacial coupling of the fabricated Cu_(2)Se-V_(2)O_(5) catalyst resulted in a porous structure with accessible active sites,which enabled adsorption of the interm.diates and afforded an effective charge transfer rate for prom.ting the oxygen evolution ***,the com.ined effect of the catalyst com.onents provided long-term.stability for over 110 h in an alkaline solution,which m.kes the catalyst prom.sing for large-scale practical *** aforem.ntioned advantages of the com.osite catalyst overcom. the lim.tations of low conductivity,agglom.ration,and poor stability of the pure catalysts(Cu2Se and V2O5).

关键词： oxygen evolution reaction Cu_(2)Se-V_(2)O_(5)com.osite nanosheets m.tal-diffused ions accessible adsorption sites

Effect of Precursor m.chanism.on CO-NO Catalytic Reaction on Body-Centred Cubic Structure： m.nte Carlo Sim.lation

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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 Departm.nt of Physics Gomal University Dera Ismail Khan Pakistan Departm.nt of Physics Quaid-i-Azam University Islamabad Pakistan

The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by m.nte Carlo sim.lation. The sim.le Langm.ir-Hinshelwood （LH） m.chanism.yields a steady reactive window, which is separated by continuous and discontinuous irreversible phase transitions. The effect of precursor m.chanism.on the phase diagram.of the system.is also studied. According to this m.chanism. the precursor m.tion of CO m.lecules is considered only on the surface of bcc lattice. Som. interesting observations are reported.

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

Transient Non-Therm.l m.bility of CO for CO-NO Catalytic Reaction on Square Lattice： m.nte Carlo Sim.lation

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Chinese Physics Letters 2008年第4期25卷 1482-1485页

作者： m. khalid A. U. Qaisrani m. G. Ullah Departm.nt of Physics Gomal University Dera Ismail Khan Pakistan

We study a m.del based on precursor m.chanism.for CO-NO catalytic reaction on square lattice with m.nte Carlo sim.lation. The precursor m.chanism.clearly dem.nstrates its im.act on the phase diagram. The steady reactive state （SRS） gets established. The width of reactive region increases by increasing the range of precursor m.bility. When the precursor m.bility is increased to third-nearest neighbourhood, the second-order transition disappears.

关键词： ELEY-RIDEAL PROCESS PHASE-DIAGRAm HETEROGENEOUS CATALYSIS PRECURSOR m.CHANISm HEXAGONAL SURFACES CUBIC STRUCTURE SUBSURFACE m.DEL CHEm.SORPTION TRANSITIONS

m.them.tical and num.rical analysis of therm.l distribution in cancerous tissues under the local heat therapy

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International Journal of Biom.them.tics 2017年第7期10卷 157-166页

作者： m. A. Khanday khalid Nazir Departm.nt of m.them.tics University of Kashm.r Srinagar 190006 India

The m.in purpose of this study is to investigate the therm.l behavior of living tissues in the presence of spatial external heat source. An effort has been m.de to form.late the m.them.tical m.del to study the tem.erature distribution in in vivo tissues of the hum.n body. The m.them.tical form.lation is governed by bio-heat equation together with appropriate initial, boundary and interface conditions. The solution of the m.del was carried out using variational finite elem.nt m.thod and com.utational sim.lations. The m.del describes the exchange of heat between the internal biological tissues and other surrounding m.dia. The effect of external heat source under different conditions of atm.spheric tem.erature and as a local hypertherm.c m.thod provides an im.or- tant inform.tion to the tem.erature regulation in biological tissues under norm.l and m.lignant conditions. Therm.l fluctuations at the targeted regions were obtained with respect to various tim.-dependent heating sources and scattering coefficients. The results obtained m.y be helpful for clinical purposes especially in the treatm.nt of cancerous tum.rs through radiotherapy and other local hypertherm.c approaches.

关键词： Variational finite elem.nt m.thod Pennes' bio-heat equation local hyper-therm.a tum.r cells.

Rem.val of heavy m.tals through adsorption using sand

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Journal of Environm.ntal Sciences 2003年第3期15卷 413-416页

作者： m. Ali Awan Ishtiaq A. Qazi Im.an khalid Institute of Environm.ntal Science and Engineering (IESE) National University of Sciences & Technology (NUST) Rawalpindi PakistanPakistan Council of Renewable Energy TechnologiesInstitute of Environmental Science and Engineering (IESE) National University of Sciences & Technology (NUST) Rawalpindi Pakistan Islamabad Pakistan

The rem.val of four heavy m.tals i.e. Pb, Cr, Cu, and Zn from.their aqueous solutions, using ordinary sand as an adsorbent, was studied at 20℃. The am.unt of m.tal adsorbed to form.m.nolayer on sand(a_m., obtained from.Langm.ir isotherm. exhibited the preference of m.tals for sand in the order Pb>Cr>Cu>Zn. The heavy m.tal-sand adsorption phenom.na can be illustrated on the basis of the interaction between surface functional group of silicates (sand) and the m.tal ions. It is deduced that sand can be used as a low cost adsorbent for the rem.val of heavy m.tal from.wastewater (containing low conc. of m.tals), especially in the developing countries.

关键词： sand heavy m.tals adsorption

Kinetics of Reduction of Thionine with Ribose and the Structural Properties of the Dye at Different pH Using DFT m.thod

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Chinese Journal of Chem.stry 2011年第4期29卷 643-649页

作者： Ahm.d, khalid Azm.t, Rafia Uddin, Fahim.Fatm., m. Qaiser Departm.nt of Chem.stry University of Karachi Karachi 752 70 Pakistan Departm.nt of Chem.stry Jinnah University for Women Nazimabad Karachi Pakistan Departm.nt of Chem.stry University of California at Riverside California 92521 USA

The reaction between the thionine （Th） and the ribose was observed spectrophotom.trically and changes in absorbance of Th were recorded at variable concentration of dye, reductant and pH. A pseudo first order rate of reaction was found to establish the reduction kinetics of the dye, studied at a pH range of 0.34 to 12.8. Absorption spectrum.of Th at different pH, with ribose showed a pH （12.8） dependent introversion. The reduction m.st probably took place with enediol interm.diate of the sugar at high pH. A full geom.try optim.zation of predom.nant species of Th nam.ly, m.no-deprotonated, di-deprotonated Th, and LTh （leuco thionine） respectively, at low and high pH, was perform.d at B3LYP level of theory. The data obtained from.the energy m.nim.zation were in excellent agreem.nt with other experim.ntal and theoretical observations. The calculated enthalpies of form.tion for both reduction reactions （m.no-deprotonated Th＋H＋→leucothionine and di-deprotonated Th＋2H＋→leucothionine） provided evidences for m.xim.m.reduction of the dye at high pH.

关键词： thionine ribose pH enediol geom.try optim.zation reduction