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SDN-Enabled Content Dissemination Scheme for the Internet of Vehicles

Computers, Materials & Continua 2023年第5期75卷 2383-2396页

作者： Abida Sharif Muhammad Imran Sharif Muhammad Attique Khan nisar ali Abdullah Alqahtani Majed Alhaisoni Ye Jin Kim Byoungchol Chang Department of Computer Science COMSATS University IslamabadPakistan Department of Computer Science HITEC University TaxilaPakistan College of Computer Engineering and Sciences Prince Sattam bin Abdulaziz UniversityAl-KharjSaudi Arabia Computer Sciences Department College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityRiyadh11671Saudi Arabia Department of Computer Science Hanyang UniversitySeoul04763Korea Center for Computational Social Science Hanyang UniversitySeoul04763Korea

The content-centric networking(CCN)architecture allows access to the content through name,instead of the physical location where the content is stored,which makes it a more robust and flexible content-based architecture.Nevertheless,in CCN,the broadcast nature of vehicles on the Internet of Vehicles(IoV)results in latency and network congestion.The IoVbased content distribution is an emerging concept in which all the vehicles are connected via the internet.Due to the high mobility of vehicles,however,IoV applications have different network requirements that differ from those of many other networks,posing new challenges.Considering this,a novel strategy mediator framework is presented in this paper for managing the network resources efficiently.Software-defined network(SDN)controller is deployed for improving the routing flexibility and facilitating in the interinteroperability of heterogeneous devices within the network.Due to the limited memory of edge devices,the delectable bloom filters are used for caching and storage.Finally,the proposed scheme is compared with the existing variants for validating its effectiveness.

关键词： Internet of vehicles(IOV) content dissemination multi mediator data traffic management

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Zr-pillared montmorillonite supported cobalt nanoparticles for Fischer–Tropsch synthesis

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Progress in Natural Science:Materials International 2013年第4期23卷 374-381页

作者： nisar Ahmad Syed Tajammul Hussain Bakhtiar Muhammad nisar ali Syed Mustansar Abbas Zulfqar ali Department of Chemistry Hazara University Nano Science and Catalysis Division National Centre for PhysicsQAU CampusIslamabadPakistan Department of Physics University of the Punjab CEES University of the Punjab

In this article Fischer–Tropsch(FT) synthesis was studied over cobalt nanoparticles supported on modifed Montmorillonite(Zr-PILC).Co-loaded/Zr-PILC catalysts were synthesized by hydrothermal methods and were characterized by XRD,XRF,BET,H2-TPR,TGA and SEM techniques.FT reactions were carried out in fxed bed microreactor(T 225 1C,260 1C and 275 1C,P 1,5 and 10 bars).The FT-products obtained over Co-loaded/Zr-PILC catalysts showed increased selectivity of C2–C12hydrocarbons and decreased selectivity towards CH4and higher molecular weight hydrocarbons(C21) at a TOS of 2–30 h as compared to the Co-loaded/NaMMT catalysts.With increase in reaction temperature from225 1C to 275 1C,CO-conversion and CH4selectivity increases while that of C5+hydrocarbons decreases.Decrease in CH4selectivity while increase in C5+hydrocarbons and CO-conversion were observed on increasing the pressure of reaction.

关键词： Fischer–Tropsch synthesis Montmorillonite Cobalt Zirconium pillared clay

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Key synthesis of magnetic Janus nanoparticles using a modified facile method

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Particuology 2014年第6期12卷 59-65页

作者： nisar ali Baoliang Zhang Hepeng Zhang Wajed Zaman Wei Li Qiuyu Zhang Key Laboratory of Applied Physics and Chemistry in Space of Ministry of Education School of ScienceNorthwestern Polytechnical University School of Material Science & Engineering Northwestern Polytechnical University

Inorganic/organic poly（methylmethacrylate-acrylic acid-divinylbenzene） iron oxide Janus magnetic nanoparticles（P（MMA-AA-DVB）/Fe3O4） with strong magnetic domains and unique surface functionalities were prepared using a solvothermal process.The P（MMA-AA-DVB） nanoparticles were prepared via soapfree emulsion polymerization and used as a precursor for preparing Janus nanoparticles.The morphology and magnetic properties of the magnetic Janus nanoparticles formed were characterized using a laser particle size analyzer,transmission electron microscopy,Fourier transform infrared spectroscopy,vibrating sample magnetometry,and thermogravimetric analysis.The synthesized P（MMA-AA-DVB）/Fe3O4 magnetic Janus nanoparticles were characterized by a Janus structure and possessed a stable asymmetric morphology after being dually functionalized.The particle size,magnetic content,and magnetic domain of the P（MMA-AA-DVB）/Fe3O4 magnetic Janus nanoparticles were 200 nm,40%,and 25 emu/g,respectively.The formation mechanism of the Janus nanoparticles was also investigated,and the results revealed that the reduction of Fe3＋ ions and growth of Fe3O4 took place on the surface of the P（MMA-AA-DVB） polymeric precursor particles.The size of the Janus particles could be controlled by narrowing the size distribution of the P（MMA-AA-DVB） precursor nanoparticles.

关键词： Janus Magnetic nanoparticles Solvothermal process Composite Emulsion polymerization

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Femtosecond laser induced nanostructuring of zirconium in liquid confined environment

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Chinese Physics B 2017年第1期26卷 310-319页

作者： nisar ali Shazia Bashir Umm-i-Kalsoom M.Shahid Rafique Narjis Begum Wolfgang Husinsky ali Ajami Chandra S.R.Natahala Laser Laboratories Institute for Applied Physics Vienna University of Technology 1040 Vienna Austria Department of Basic Sciences and Humanities University of Engineering and Technology Lahore Faisalabad Campus Faisalabad Pakistan Laser Laboratories Centre for Advanced Studies m Physics GC University 1-Church Road Lahore Pakistan Department of Physics GC University Kachehri Road Lahore Pakistan Department of Physics Riphah International University Islamahad (Lahore Campus) Lahore Pakistan Department of Physics University of Engineering and Technology Lahore Pakistan Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan

The surface, structural, and mechanical properties of zirconium after irradiation with Ti： sapphire laser（800 nm, 30 fs,1 k Hz） have been investigated. The zirconium targets were exposed for a varying number of laser pulses ranging from 500 to 2000 at a fixed fluence of 3.6 J/cm^2 corresponding to an intensity of 1.2×10^14W/cm^2 in ambient environments of deionized water and propanol. A scanning electron microscope（SEM） was employed to investigate the surface morphology of the irradiated zirconium. The SEM analysis shows the formation of various kinds of features including nanoscale laser induced periodic surface structures（LIPSS）, sponge like surface structure, flakes, conical structures, droplets, pores, and cavities. The energy dispersive x-ray spectroscopy（EDS） analysis exhibits the variation in chemical composition along with an enhanced diffusion of oxygen under both ambient conditions. The crystal structure and phase analyses of the exposed targets were explored by x-ray diffraction（XRD） and Raman spectroscopy techniques, respectively. The XRD analysis confirms the presence of various phases of zirconium hydride and zirconia after ablation in both de-ionized water and propanol. However, excessive hydrides are formed in the case of propanol. The Raman analysis supports the EDS and XRD results. It also reveals the presence of oxides（zirconia） after irradiation in both de-ionized water and propanol environments.The chemical reactivity of zirconium was significantly improved in the presence of liquids which were accountable for the growth of novel phases and modification in the chemical composition of the irradiated Zr. A nanohardness tester was employed to measure the nanohardness of the laser treated targets. The initial increase and then decrease in nanohardness was observed with an increase in the number of laser pulses in the de-ionized water environment. In the case of propanol,a continuous decrease in hardness was observed.

关键词： ambient environments periodic structure crystallinity synthesis

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Engineered Hybrid Materials with Smart Surfaces for Effective Mitigation of Petroleum-Originated Pollutants

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Engineering 2021年第10期7卷 1492-1503页

作者： nisar ali Muhammad Bilal Adnan Khan Farman ali Mohamad Nasir Mohamad Ibrahim Xiaoyan Gao Shizhong Zhang Kun Hong Hafiz MNIqbal Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province National and Local Joint Engineering Research Center for Deep Utilization Technology of Rock-salt ResourceFaculty of Chemical EngineeringHuaiyin Institute of TechnologyHuaian 223003China School of Life Science and Food Engineering Huaiyin Institute of TechnologyHuaian 223003China Institute of Chemical Sciences University of PeshawarPeshawar 25120Pakistan Department of Chemistry Hazara UniversityMansehra 21300Pakistan School of Engineering and Sciences School of Chemical SciencesUniversiti Sains MalaysiaPenang 11800Malaysia School of Engineering and Sciences Tecnologico de MonterreyMonterrey 64849Mexico

The generation and controlled or uncontrolled release of hydrocarbon-contaminated industrial wastewater effluents to water matrices are a major environmental concern.The contaminated water comes to surface in the form of stable emulsions,which sometimes require different techniques to mitigate or separate effectively.Both the crude emulsions and hydrocarbon-contaminated wastewater effluents contain suspended solids,oil/grease,organic matter,toxic elements,salts,and recalcitrant chemicals.Suitable treatment of crude oil emulsions has been one of the most important challenges due to the complex nature and the substantial amount of generated waste.Moreover,the recovery of oil from waste will help meet the increasing demand for oil and its derivatives.In this context,functional nanostructured materials with smart surfaces and switchable wettability properties have gained increasing attention because of their excellent performance in the separation of oil–water emulsions.Recent improvements in the design,composition,morphology,and fine-tuning of polymeric nanostructured materials have resulted in enhanced demulsification functionalities.Herein,we reviewed the environmental impacts of crude oil emulsions and hydrocarbon-contaminated wastewater effluents.Their effective treatments by smart polymeric nanostructured materials with wettability properties have been stated with suitable examples.The fundamental mechanisms underpinning the efficient separation of oil–water emulsions are discussed with suitable examples along with the future perspectives of smart materials.

关键词： Emulsion Hydrocarbon-contamination Environment impacts Hybrid nanomaterials Oil-water separation Wastewater treatment

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Effect of Power and Nitrogen Content on the Deposition of CrN Films by Using Pulsed DC Magnetron Sputtering Plasma

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Plasma Science and Technology 2013年第7期15卷 666-672页

作者： Umm-i-KALSOOM R.AHMAD nisar ali I.A.KHAN Sehrish SALEEM Uzma IKHLAQ Nasarullah KHAN Department of Physics Govt. College UniversityLahore 54000 Pakistan Department of Physics Govt. College UniversityFaisalabad 38000 Pakistan

CrN thin films are deposited on stainless steel （AISI-304） substrate using pulsed DC magnetron sputtering in a mixture of nitrogen and argon plasma. Two set of samples are prepared. The first set of sample is treated at different powers （100 W to 200 W） in a mixture of argon （95%） and nitrogen （5%）. The second set of samples is treated at different nitrogen concentrations （5% to 20%） in argon （95% to 80%） for a constant power （150 W）. X-ray diffraction （XRD） analysis exhibits the development of new phases related to different compounds. The crystallinity of CrN varies by varying the applied power and nitrogen content. Crystallite size and residual stresses of the CrN （111） plane show similar variation for the applied power and nitrogen contents. Scanning electron microscopy （SEM） analysis shows the formation of a granular surface morphology that varies with the change of powers and nitrogen content. The thickness of the film is measured using SEM cross sectional images and using atomic force microscopy （AFM） scratch analysis. The maximum film thickness （about 755 nm） is obtained for the film deposited at 5% nitrogen in 95% argon at 150 W power. For these conditions, maximum hardness is also observed.

关键词： sputtering crystallinity morphology thickness roughness

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Effect of fluence and ambient environment on the surface and structural modification of femtosecond laser irradiated Ti

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Chinese Physics B 2016年第1期25卷 789-795页

作者： Umm-i-Kalsoom Shazia Bashir nisar ali M Shahid Rafique Wolfgang Husinsky Chandra S R Nathala Sergey V Makarov Narjis Begum Institute for Applied Physics Vienna University of TechnologyViennaAustria Centre for Advanced Studies in Physics GC University LahorePakistan Department of Physics The University of LahorePala'stan Department of Basic Sciences and Humanities University of Engineering and Technology FasalabadPakistan Department of Physics University of Engineering and Technology LahorePakistan P.N.Lebedev Physics Institute RAS MoscowRussia Department of Physics COMSATS Institute of Information and TechnologyIslamabadPakistan

Under certain conditions, ultrafast pulsed laser interaction with matter leads to the formation of self-organized conical as well as periodic surface structures （commonly reffered to as, laser induced periodic surface structures, LIPSS）. The purpose of the present investigations is to explore the effect of fsec laser fluence and ambient environments （Vacuum ＆ 02） on the formation of LIPSS and conical structures on the Ti surface. The surface morphology was investigated by scanning electron microscope （SEM）. The ablation threshold with single and multiple （N = 100） shots and the existence of an incubation effect was demonstrated by SEM investigations for both the vacuum and the 02 environment. The phase analysis and chemical composition of the exposed targets were performed by x-ray diffraction （XRD） and energy dispersive x-ray spectroscopy （EDS）, respectively. SEM investigations reveal the formation of LIPSS （nano ＆ micro）. FFT d-spacing calculations illustrate the dependence of periodicity on the fluence and ambient environment. The periodicity of nano-scale LIPSS is higher in the case of irradiation under vacuum conditions as compared to 02. Furthermore, the 02 environment reduces the ablation threshold. XRD data reveal that for the 02 environment, new phases （oxides of Ti） are formed. EDS analysis exhibits that after irradiation under vacuum conditions, the percentage of impurity element （A1） is reduced. The irradiation in the 02 environment results in 15% atomic diffusion of oxygen.

关键词： LIPSS ablation threshold incubation coefficient structural modification

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Viscous effects on plasmoid formation from nonlinear resistive tearing growth in a Harris sheet

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Plasma Science and Technology 2022年第1期24卷 18-29页

作者： nisar AHMAD 朱平 Ahmad ali 曾市勇 CAS Key Laboratory of Geospace Environment and Department of Engineering and Applied Physics University of Science and Technology of ChinaHefei 230026People's Republic of China International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China Department of Engineering Physics University of Wisconsin-MadisonMadisonWisconsin 53706United States of America Pakistan Tokamak Plasma Research Institute Islamabad 44000Pakistan Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People’s Republic of China

In this work,the evolution of a highly unstable m=1 resistive tearing mode,leading to plasmoid formation in a Harris sheet,is studied in the framework of full MHD model using the Non-Ideal Magnetohydrodynamics with Rotation,Open Discussion simulation.Following the initial nonlinear growth of the primary m=1 island,the X-point develops into a secondary elongated current sheet that eventually breaks into plasmoids.Two distinctive viscous regimes are found for the plasmoid formation and saturation.In the low viscosity regime(i.e.P_(r)■1),the plasmoid width increases sharply with viscosity,whereas in the viscosity dominant regime(i.e.P_(r)■1),the plasmoid size gradually decreases with viscosity.Such a finding quantifies the role of viscosity in modulating the plasmoid formation process through its effects on the plasma flow and the reconnection itself.

关键词： viscosity reconnection plasmoids Prandtl number

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A Color Image Encryption Scheme Based on Singular Values and Chaos

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Computer Modeling in Engineering & Sciences 2023年第10期137卷 965-999页

作者： Adnan Malik Muhammad ali Faisal S.Alsubaei nisar Ahmed Harish Kumar Electrical Engineering Department University of Engineering and TechnologyLahore54000Pakistan Department of Cybersecurity College of Computer Science and EngineeringUniversity of JeddahJeddah21959Saudi Arabia Computer Engineering Department University of Engineering and TechnologyLahore54000Pakistan Department of Computer Science College of Computer ScienceKing Khalid UniversityAbha61421Saudi Arabia

The security of digital images transmitted via the Internet or other public media is of the utmost importance.Image encryption is a method of keeping an image secure while it travels across a non-secure communication medium where it could be intercepted by unauthorized entities.This study provides an approach to color image encryption that could find practical use in various contexts.The proposed method,which combines four chaotic systems,employs singular value decomposition and a chaotic sequence,making it both secure and compression-friendly.The unified average change intensity,the number of pixels’change rate,information entropy analysis,correlation coefficient analysis,compression friendliness,and security against brute force,statistical analysis and differential attacks are all used to evaluate the algorithm’s performance.Following a thorough investigation of the experimental data,it is concluded that the proposed image encryption approach is secure against a wide range of attacks and provides superior compression friendliness when compared to chaos-based alternatives.

关键词： Encryption image encryption chaos theory color image encryption singular value decomposition compression friendliness

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Surface Analysis Correlated with Structural and Mechanical Properties of Laser Irradiated Brass

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Materials Sciences and Applications 2015年第1期6卷 23-32页

作者： Shahbaz Ahmad Shazia Bashir Daniel Yousaf nisar ali Tousif Hussain Center for Advanced Studies in Physics Government College University Lahore Pakistan

Brass targets were irradiated with various laser pulses of Excimer laser ranging from 1200 to 3000 for constant fluence of 3.4 J/cm2 in oxygen atmosphere (100 Torr). The surface morphology and crystallographic analyses were performed by using Scanning Electron Microscope (SEM) and X-Ray Diffractometer (XRD). SEM analysis reveals the formation of laser-induced micro-sized cavities, bumps, cones and wave-like ridges with non-uniform shape and density distribution. These features are formed for all number of pulses;however with increasing number of pulses from 1200 to 2400, the density of cavities decreases whereas, the wave-like ridges become more pronounced and bump-formation is vanished. For maximum number of 3000 shots, the appearance of cones and wave-like ridges becomes diffusive, whereas the density and size of cavities increase again. XRD analysis demonstrates that no new phases are formed in irradiated brass. However, the change in peak intensity along with lower and higher angle shifting is observed which is attributed to generation of laser induced stresses. The Yield Stress (YS), Ultimate Tensile Strength (UTS) as well as Microhardness increase monotonically with increasing number of laser pulses.

关键词： Laser Pulses Surface Morphology Mechanical Properties Crystallographic Alteration

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