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Structural and optical properties of thermally reduced graphene oxide for energy devices

Chinese Physics B 2017年第8期26卷 346-352页

作者： Ayesha Jamil Faiza Mustafa Samia Aslam usman Arshad muhammad Ashfaq Ahmad Department of Physics COMSATS Institute of Information TechnologyLahore 54000Pakistan

Natural intercalation of the graphite oxide, obtained as a product of Hummer＇s method, via ultra-sonication of water dispersed graphite oxide has been carried out to obtain graphene oxide（GO） and thermally reduced graphene oxide（RGO）.Here we report the effect of metallic nitrate on the oxidation properties of graphite and then formation of metallic oxide（MO） composites with GO and RGO for the first time. We observed a change in the efficiency of the oxidation process as we replaced the conventionally used sodium nitrate with that of nickel nitrate Ni（NO_3）_2, cadmium nitrate Cd（NO_3）_2,and zinc nitrate Zn（NO_3）_2. The structural properties were investigated by x-ray diffraction and observed the successful formation of composite of MO–GO and MO–RGO（M = Zn, Cd, Ni）. We sought to study the effect on the oxidation process through optical characterization via UV-Vis spectroscopy and Fourier Transform Infrared（FTIR） ***, Thermo Gravimetric Analysis（TGA） was carried out to confirm 〉 90% weight loss in each process thus proving the reliability of the oxidation cycles. We have found that the nature of the oxidation process of graphite powder and its optical and electrochemical characteristics can be tuned by replacing the sodium nitrate（NaNO_3） by other metallic nitrates as Cd（NO_3）_2, Ni（NO_3）_2, and Zn（NO_3）_2. On the basis of obtained results, the synthesized GO and RGO may be expected as a promising material in antibacterial activity and in electrodes fabrication for energy devices such as solar cell, fuel cell,and super capacitors.

关键词： thermal properties of graphene oxide and reduced graphene oxide optical properties structuralproperties fuel cell composite materials

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Facile synthesis of ironenickelecobalt ternary oxide(FNCO)mesoporous nanowires as electrode material for supercapacitor application

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Journal of Materiomics 2022年第1期8卷 221-228页

作者： muhammad usman muhammad Tayyab Ahsan Sofia Javed Zeeshan Ali Yiqiang Zhan Irfan ahmed Sajid Butt Mohammad Islam Asif Mahmood M.Aftab Akram School of Chemical and Materials Engineering National University of Sciences and Technology(NUST)Sector H-12Islamabad44000Pakistan Department of Materials Science and Engineering College of EngineeringPeking University100871BeijingChina State Key Laboratory of ASIC and System Center of Micro-Nano SystemSISTFudan UniversityShanghai200433China Department of Materials Science and Engineering Institute of Space TechnologyIslamabad44000Pakistan New Mexcico Institute of Mining&Technology SocorroNM 87801USA School of Chemical and Biomolecular Engineering The University of Sydney2006SydneyAustralia

Transition Metal Oxides have drawn significant attention due to their reversible chemical redox reaction and long-life *** agglomeration and shrinkage/expansion of transition metal oxides in the nanosize regime have a noticeable effect on their electrochemical *** in this work,mesoporous nanowires(NWs)with a typical composition of iron-nickel-cobalt ternary oxide(FNCO)are synthesized using a simple,facile and cost-effective hydrothermal process followed by furnace *** NWs are then extensively investigated as an electrode material for supercapacitor *** compare the electrochemical properties,nanowires of nickel-cobalt oxide(NCO),iron-cobalt oxide(FCO)and cobalt oxide(CO)were also produced by following the same *** FNCO NWs are found to overcome the shortcomings in the electrochemical energy storage devices by exhibiting higher values of specific capacitance(2197 Fg^(-1))and energy density(109 Whkg^(-1))at 1 Ag^(-1) current ***,the FNCO NWs also showed a cyclic charge/discharge stability of 96%even up to 20,000 ***,a FNCO//graphene asymmetric device,fabricated with FNCO NWs and graphene as positive and negative electrodes,respectively,which exhibit high energy density(47 Whkg^(-1)),power density(375 Wkg^(-1))and excellent capacitance retention(86%)after 15,000 cycles.

关键词： Electrochemistry Hydrothermal synthesis Nanowires Supercapacitor Transition metal oxides

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Smart Healthcare Using Data-Driven Prediction of Immunization Defaulters in Expanded Program on Immunization (EPI)

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Computers, Materials & Continua 2021年第1期66卷 589-602页

作者： Sadaf Qazi muhammad usman Azhar Mahmood Aaqif Afzaal Abbasi muhammad Attique Yunyoung Nam Predicitive Analytics Laboratory Shaheed Zulfikar Ali Bhutto Institute of Science and TechnologyIslamabad44000Pakistan Department of Software Engineering Foundation University IslamabadIslamabad44000Pakistan Department of Software Sejong UniversitySeoul05006Korea Department of Computer Science and Engineering Soonchunhyang UniversityAsan31538Korea

Immunization is a noteworthy and proven tool for eliminating lifethreating infectious diseases,child mortality and *** Program on Immunization(EPI)is a nation-wide program in Pakistan to implement immunization activities,however the coverage is quite low despite the accessibility of free *** study proposes a defaulter prediction model for accurate identification of *** proposed framework classifies defaulters at five different stages:defaulter,partially high,partially medium,partially low,and unvaccinated to reinforce targeted interventions by accurately predicting children at high risk of defaulting from the immunization *** machine learning algorithms are applied on Pakistan Demographic and Health Survey(2017–18)*** Perceptron yielded 98.5%accuracy for correctly identifying children who are likely to default from immunization series at different risk stages of being *** this paper,the proposed defaulters’prediction framework is a step forward towards a data-driven approach and provides a set of machine learning techniques to take advantage of predictive ***,predictive analytics can reinforce immunization programs by expediting targeted action to reduce ***,the accurate predictions support targeted messages sent to at-risk parents’and caretakers’consumer devices(e.g.,smartphones)to maximize healthcare outcomes.

关键词： Smart healthcare routine immunization predictive analytics defaulters vaccination machine learning targeted messaging

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Studies on batch adsorptive removal of cadmium and nickel from synthetic waste water using silty clay originated from Balochistan-Pakistan

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1171-1176页

作者： Abdul Samad muhammad Imran Din Mahmood ahmed Institute of Chemistry University of the PunjabLahore 54590Pakistan Renacon Pharma Limited Lahore 54600Pakistan

The potentials of silty clay(SC),acquired from Chaman,Balochistan,were investigated as adsorbent for Ni(Ⅱ)and Cd(Ⅱ)removal from contaminated *** influence of different operating factors like dose,pH,temperature,and time of contact was explored,and optimum values were noted under batch adsorption *** study was conducted with varying concentrations of solutions on optimized conditions and different adsorption models i.e.,Langmuir,Freundlich,Temkin and Dubinin-Radushkevich(D-R)isotherm,which were employed to interpret the *** isothermal data of both Ni(Ⅱ)and Cd(Ⅱ)were well fitted to Langmuir isotherm suggesting the formation of monolayer of metal ions on silty *** values of adsorption capacity noted for Ni(Ⅱ)and Cd(Ⅱ)were 3.603 mg·g^-1 and 5.480 mg·g^-1,*** studies affirmed that pseudo second order(PSO)kinetics was being obeyed by the removal of Ni(Ⅱ)and Cd(Ⅱ).Thermodynamic variables like free energy change(ΔG°),enthalpy change(ΔH°)and entropy change(ΔS°)were *** negative value ofΔG°and the positive values ofΔH°andΔS°unfolded that the removal process of both metal ions of by SC was spontaneous,endothermic and feasible.

关键词： Adsorption Kinetics Isotherm Toxicity Silty clay Thermodynamics

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Energy and flux measurements of laser-induced silver plasma ions by using Faraday cup

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Plasma Science and Technology 2021年第8期23卷 188-198页

作者： muhammad usman Aslam BHATTI Shazia BASHIR Asma HAYAT Khaliq MAHMOOD Rana AYUB Mubashir JAVED muhammad Shahzad KHAN Centre for Advanced Studies in Physics(CASP) GC UniversityLahore 54000Pakistan

Silver(Ag)plasma has been generated by employing Nd:YAG laser(532 nm,6 ns)laser *** energy and flux of ions have been evaluated by using Faraday cup(FC)using time of flight(TOF)*** dual peak signals of fast and slow Ag plasma ions have been *** energy and flux of fast and slow ions tend to increase with increasing irradiance from 7 GW cm-2 to 17.9 GW cm-2 at all distances of FC from the target *** a decreasing trend of energies and flux of ions has been observed with increasing distance of FC from the *** maximum value of flux of the fast component is21.2×10^(10) cm^(-2),whereas for slow ions the maximum energy and flux values are 8.8 keV,8.2×10^(10) cm^(-2) *** the analysis of plume expansion dynamics,the angular distribution of ion flux measurement has also been *** overall analysis of both spatial and angular distributions of Ag ions revealed that the maximum flux of Ag plasma ions has been observed at an optimal angle of~15°.In order to confirm the ion acceleration by ambipolar field,the self-generated electric field(SGEF)measurements have also been performed by electric probe;these SGEF measurements tend to increase by increasing laser *** maximum value of 232 V m^(-1) has been obtained at a maximum laser irradiance of 17.9 GW cm^(-2).

关键词： laser ablation laser-induced plasma ions Faraday cup time of flight measurements self-generated electric field angular distribution

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Intelligent wireless walls for contactless in-home monitoring

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Light(Science & Applications) 2022年第10期11卷 2308-2320页

作者： muhammad usman James Rains Tie Jun Cui muhammad Zakir Khan Jalil Ur Rehman Kazim muhammad Ali Imran Qammer H.Abbasi University of Glasgow James Watt School of EngineeringGlasgow G128QQUK State Key Laboratory of Millimetre Waves Southeast UniversityNanjingChina

Human activity monitoring is an exciting research area to assist independent living among disabled and elderly *** techniques have been proposed to recognise human activities,such as exploiting sensors,cameras,wearables,and contactless microwave *** these,the microwave sensing has recently gained significant attention due to its merit to solve the privacy concerns of cameras and discomfort caused by ***,the existing microwave sensing techniques have a basic disadvantage of requiring controlled and ideal settings for high-accuracy activity detections,which restricts its wide adoptions in non-line-of-sight(Non-LOS)***,we propose a concept of intelligent wireless walls(IWW)to ensure high-precision activity monitoring in complex environments wherein the conventional microwave sensing is *** IWW is composed of a reconfigurable intelligent surface(RIS)that can perform beam steering and beamforming,and machine learning algorithms that can automatically detect the human activities with high *** complex environments are considered:one is a corridor junction scenario with transmitter and receiver in separate corridor sections and the other is a multi-floor scenario wherein the transmitter and receiver are placed on two different floors of a *** each of the aforementioned environments,three distinct body movements are considered namely,sitting,standing,and *** subjects,one male and one female perform these activities in both *** is demonstrated that IWW provide a maximum detection gain of 28%in multi-floor scenario and 25%in corridor junction scenario as compared to traditional microwave sensing without RIS.

关键词： microwave environments floor

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Analysis of Factors that Affect Government Digitization:A Pilot Case Study of Pakistan

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Computers, Materials & Continua 2021年第1期66卷 291-301页

作者： Salman ahmed muhammad Ali Khan Department of Computer Systems Engineering University of Engineering&TechnologyPeshawarPakistan

One of the greatest factors that affects the economic condition of a country is its *** the model of good governance,the primary elements for stronger institution include efficiency,transparency,and accountability;and technology plays a major role in improving these ***,there are myriad of challenges when it comes to practical integration of technology in these institutions for *** is more challenging when a country is developing and one that is already weak *** is also important to mention that the challenges of digitization in public sector is not limited to developing countries *** is equally challenging,even today,in already developed countries to digitally transform their public institutions for improved policymaking and for responsive service *** factors contribute to the failure of such digitization initiatives,more so within developing *** the purpose of this paper is to identify those factors,to measure the significance of each of those factors,and to realize and overcome *** research considered the case study of Pakistan;however,the results are very likely to match the conditions of other developing regions around the *** questionnaires and interviews,valuable feedback was gathered from up to 25 senior government officers that are closely associated with digitization initiatives in public *** feedback to the questions were overall *** results indicate the most significant of factors that affect government digitization in this developing region,including some factors that were not expected.

关键词： E-governance government digitization information management sustainability

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Triple Key Security Algorithm Against Single Key Attack on Multiple Rounds

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Computers, Materials & Continua 2022年第9期72卷 6061-6077页

作者： muhammad Akram muhammad Waseem Iqbal Syed Ashraf Ali muhammad usman Ashraf Khalid Alsubhi Hani Moaiteq Aljahdali Department of Computer Science Superior University Lahore54000Pakistan Department of Software Engineering Superior University Lahore54000Pakistan Department of Computer Science The Institute of Management Sciences(PAK-AIMS)Lahore54000Pakistan Department of Computer Science GC Women University SialkotPakistan Department of Computer Science King Abdulaziz UniversityJeddahSaudi Arabia Faculty of Computing and Information Technology King Abdulaziz UniversityJeddahSaudi Arabia

In cipher algorithms,the encryption and decryption are based on the same *** are some limitations in cipher algorithms,for example in polyalphabetic substitution cipher the key size must be equal to plaintext otherwise it will be repeated and if the key is known then encryption becomes *** paper aims to improve the said limitations by designing of Triple key security algorithm(TKS)in which the key is modified on polyalphabetic substitution cipher to maintain the size of the key and *** plaintext character is substituted by an alternative *** mode of substitution is transformed cyclically which depends on the current position of the modified *** keys are used in the encryption and decryption process on 8 or 16 rounds with the Exclusively-OR(XOR)of the 1st *** study also identifies a single-key attack on multiple rounds block cipher in mobile communications and applied the proposed technique to prevent the *** utilization of the TKS algorithm,the decryption is illustrated,and security is analyzed in detail with mathematical examples.

关键词： Encryption decryption cipher symmetric key cryptography single key attack

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Performance Evaluation of MWCNTs Reinforced Cement Mortar Composites using Natural and Commercial Surfactants

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Journal of Wuhan University of Technology(Materials Science) 2022年第1期37卷 47-57页

作者： Qareeb Ullah Rao Arsalan Khushnood Sajjad Ahmad muhammad usman Shad muhammad Jean-Marc Tulliani School of Civil and Environmental Engineering National University of Sciences and TechnologyIslamabad-44000Pakistan Department of Structural Geotechnical and Building EngineeringPolitecnico di TorinoTurin-10129Italy Department of Civil Engineering FE&TBahauddin Zakariya UniversityMultan-56000Pakistan Department of Applied Science and Technology Politecnico di TorinoTurin-10129Italy

An efficient and promising approach for effectively dispersing multi-walled carbon nanotubes(MWCNTs)in cementitious composites has been *** naturally occurring organic extracts from species of indigenously known‘Keekar’trees scattered along tropical and sub-tropical regions;is found as an exceptional replacement to the non-natural commercial *** the initial phase of investigation,ideal surfactant’s content required for efficient dispersion of MWCNTs in solution was determined using ultra-violet *** experimental investigations were then extended to five different cement composite formulations containing 0.0,0.025,0.05,0.08 and 0.10%MWCNTs by weight of *** was observed that the natural surfactant produced efficient dispersion at much reduced cost(approx.14%)compared with the commercial *** estimated weight efficiency factor f was found 6.5 times higher for the proposed sustainable replacement to the conventional along with remarkable increase of 23%in modulus of rupture on 0.08 wt%addition of *** strength enhancement,the dispersed MWCNTs also improved the first crack and ultimate fracture toughness by 51.5%and 35.9%,*** field emission scanning electron microscopy of the cryofractured samples revealed efficient dispersion of MWCNTs in the matrix leading to the phenomenon of effective crack bridging and crack branching in the composite ***,the proposed scheme significantly reduced the early age volumetric shrinkage by 39%.

关键词： MWCNTs acacia nilotica gum keekar triton X-100 fracture crack bridging cement mortar early age micro-cracking sustainability

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Evaluation of cotton germplasm for morphological and biochemical host plant UPdates resistance traits against sucking insect pests complex

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Journal of Cotton Research 2021年第3期4卷 211-218页

作者： RIZWAN muhammad ABRO Saifullah ASIF muhammad usman HAMEED Amjad MAH BOOB Wajid DEHO Zaheer ahmed SIAL Mahboob Ali Nuclear Institute of Agriculture(NIA) TandojamSindh 70060Pakistan Nuclear Institute for Agriculture and Biology(NIAB) Faisalabad 38000Pakistan College of Plant Science and Technology Huazhong Agricultural UniversityWuhan 430070China

Background:Sucking insect pests cause severe damage to cotton crop *** development of insect resistant cotton cultivars is one of the most effective measures in curtailing the yield *** the role of morphological and biochemical host plant resista nee(HPR)traits in plant defense,12 cotton genotypes/varieties were evaluated for leaf area,leaf glanding,total soluble sugars,total soluble proteins,total phenolics,tannin and total flavonoids against fluctuating populations of whitefly,thrips and jassid under field ***:The population of these insects fluctuated during the growing seas on and remained above threshold level(whitefly>5,thrips>(8-10)f or jassid>1 per leaf)during late June and early *** and negative association of whitefly(r=-0.825)and jassid(r=-0.929)with seed cotton yield was *** population of insects were the highest in Glandless-1 followed by NIA-82 and ***-Kiran followed by NI AB-878 and Sadori were the most resistant,with the mean population of 1.41,1.60,1.66(whitefly);2.24,232,2.53(thrips)and 037,0.31,036(jassid),*** resistant variety NIAB-Kiran showed less soluble sugars(8.54 mg.g^(-1)),soluble proteins(27.11 mg.g^(-1))and more phenolic(36.56 mg.g^(-1))and flavonoids(13.10mg.g^(-1))as compared with the susceptible check ***,all insect populations were positively correlated with total soluble sugars and *** populations exhibited negative response to leaf gossypol glands,total phenolics,tannins and *** thrips and jassid populations had a significant and negative correlation with these four biochemical HPR ***:The ide ntified resistant resources and HPR traits can be deployed against sucking in sect pests'complex in future breeding programs of developing insect resistant cotton varieties.

关键词： Gossypium Insect resistance Plant defense Plant breeding Resistant traits Sucking in sects

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