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Natural Propulsion with Lorentz Force and Nanoparticles in a Bioinspired Lopsided Ciliated Channel

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Journal of Bionic Engineering 2017年第1期14卷 172-181页

作者： Noreen Sher Akbar Liaqat Ali Khan zafar Hayat Khan Nazir Ahmed Mir DBS&H CEME National University of Sciences and Technology Islamabad Pakistan Basic Science Department Ripha International University Islamabad Pakistan Department of Mathematics University of Malakand Chakdara Dir (Lower) Khyber Pakhtunkhwa Pakistan

The transportation of biological and industrial nanofluids by natural propulsion like cilia movement and self-generated contraction-relaxation of flexible walls has tremendous applications in various fields. Inspired by multidisciplinary invention in this direction, a fuid mechanical model is proposed to study the Magneto-hydrodynamics （MHD） and heat transfer for nanofluids fabricated by the dispersion of nanoparticles in water as base fluid. The steady flow is induced by metachronal wave propulsion due to beating cilia. The flow regime is asymmetric channel. The flow is restricted under the low Reynolds number and long wavelength approximations. Cilia boundary conditions for velocity components are employed to find the exact solutions. The impacts of pertinent physical parameters on temperature profile, velocity profile, pressure, and stream lines are computed numerically. It is observed that velocity is inversely proportional to magnetic Reynolds number, Reynolds number, Strommer＇s number and velocity is directly proportional to flow rate. It is analyzed that temperature is inversely proportional to Strommer＇s number and magnetic Reynolds number and directly proportional to Brinkmann number and flow rate. The temperature is maximum at the center of the channel and it starts decreasing towards the boundary walls.

关键词： copper water nanoparticles induced magnetic field asymmetric ciliated channel

Wild melon: a novel non-edible feedstock for bioenergy

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Petroleum Science 2018年第2期15卷 405-411页

作者： Maria Ameen Muhammad zafar Mushtaq Ahmad Anjuman Shaheen Ghulam Yaseen Biofuel Laboratory Department of Plant Sciences Quaid-i-Azam University Department of Environmental Science Female CampusInternational Islamic University Islamabad

In the present research work, a non-edible oil source Cucumis melo var. agrestis （wild melon） was systematically identified and studied for biodiesel production and its characterization. The extracted oil was 29.1% of total dry seed weight. The free fatty acid value of the oil was found to be 0.64%, and the single-step alkaline transesterification method was used for conversion of fatty acids into their respective methyl esters. The maximum conversion efficiency of fatty acids was obtained at 0.4 wt% NaOH （used as catalyst）, 30% （methanol to oil, v/v） methanol amount, 60 ℃ reaction temperature, 600-rpm agitation rate and 60-min reaction time. Under these optimal conditions, the conversion efficiency of fatty acid was 92%. However, in the case of KOH as catalyst, the highest conversion （85%） of fatty acids was obtained at 40% methanol to oil ratio, 1.28 wt% KOH, 60 ℃ reaction temperature, 600-rpm agitation rate and 45 min of reaction time. Qualitatively, biodiesel was characterized through Fourier transform infrared spectroscopy （FFIR） and gas chromatography and mass spectroscopy （GC-MS）. FTIR results demonstrated a strong peak at 1742 cm-1, showing carbonyl groups （C=O） of methyl esters. However, GC-MS results showed the presence of twelve methyl esters comprised of lauric acid, myristic acid, palmitic acid, non-decanoic acid, hexadecanoic acid, octadecadienoic acid and octadecynoic acid. The fuel properties were found to fall within the range recommended by the international biodiesel standard, i.e., American Society of Testing Materials （ASTM）： flash point of 91℃, density of 0.873 kg/L, viscosity of 5.35 cSt, pour point of - 13 ℃, cloud point of -10 ℃, total acid number of 0.242 mg KOH/g and sulfur content of 0.0043 wt%. The present work concluded the potential of wild melon seed oil as excellent non-edible source of bioenergy.

关键词： Cucumis melo var. agrestis Wild melon seed oil (WMSO) Transesterification Bioenergy Characterization Fuel properties

Influence of ectomycorrhizal inoculation on Pinus wallichiana and Cedrus deodara seedlings under nursery conditions

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Frontiers in Biology 2014年第1期9卷 82-88页

作者： Zahoor Ahmad ITOO zafar A. RESHI Biological Invasions Research Lab Department of Botany University of Kashmir Srinagar 190006 India

A study was undertaken to examine the extent of root colonization by four locally isolated ectomycorrhizal （ECM） fungi （Hebeloma theobrominum, Boletus dryophilus, Scleroderma citrinum and Suillus luteus） and their effects on seedling growth in Pinus wallichiana and Cedrus deodara under nursery conditions. Seedlings of the two conifers were inoculated with mycelium of ECM fungi and were grown in pots containing sterilized forest soil for six months. The percentage of ECM colonization of roots was 38%-52% in Pinus wallichiana and 33%-48~ in Cedrus deodara. ECM colonization increased shoot height, needle number, shoot and root biomass and survival of inoculated seedlings. Among the four ECM fungi Hebeloma theobrominum was more effective with Pinus wallichiana and Scleroderma citrinum with Cedrus deodara in promoting seedling survival and overall growth. All the four ECM fungi used enhanced growth of inoculated seedlings and thus can be used in afforestation and regeneration programmes in degraded forests ecosystems.

关键词： afforestation colonization ectomycorrhizal mycelium seedling survival

Nitrite sensor using activated biochar synthesised by microwave-assisted

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Waste Disposal and Sustainable Energy 2023年第1期5卷 1-11页

作者： Scarlett Allende Yang Liu Muhammad Adeel zafar Mohan V.Jacob Electronics Material Lab College of Science and EngineeringJames Cook UniversityTownsvilleQLD4811Australia College of Science and Engineering James Cook UniversityTownsvilleQLD4811Australia

Developing applications for the by-products obtained from waste processing is vital for resource *** synthesis of ZnCl2-activated biochar with high electrocatalytic activity was carried out by the microwave-assisted pyrolysis of pineapple peel and subsequent chemical activation *** biochar is employed in the electrochemical sensing of nitrite by drop casting in a glassy carbon electrode(GCE).The activated biochar exhibited a stacked carbon sheet,254 m2 g−1 Brunauer,Emmett and Teller(BET)surface area,0.076 cm3 g−1 pore volume,189.53 m2 g−1 micropore area and oxygen-containing functional *** electrochemical impedance spectroscopy of the modified GCE showed a reduced charge transfer resistance of 61%.This is crucial to determine the electrochemical properties of *** sensor showed a significant current response and an excellent limit of detection of 0.97µmol L−*** modified-activated biochar electrochemical sensor demonstrated high selectivity,reproducibility(RSD=2.4%),and stability(RSD=2.6%).

关键词： Microwave-assisted pyrolysis Biochar Nitrite Electrochemical sensor

Estimation of boundary-layer flow of a nanofluid past a stretching sheet: A revised model

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Journal of Hydrodynamics 2016年第4期28卷 596-602页

作者： Naeema ISHFAQ zafar Hayat KHAN Waqar Ahmad KHAN Richard J.CULHAM School of Mathematical Sciences Peking University Department of Mathematics University of MalakandDir (Lower) Department of Mechanical and Industrial Engineering College of EngineeringMajmaah University Department of Mechanical Engineering University of Waterloo

The previous model for the boundary layer nanofluid flow past a stretching surface with a specified nanoparticle volume fraction on the surface is *** major limitation of the previous model is the active control of the nanoparticle volume fraction on the *** a revised model proposed in this paper,the nanoparticle volume fraction on the surface is passively controlled,which accounts for the effects of both the Brownian motion and the thermophoresis under the boundary condition,whereas the Buongiorno＇s model considers both effects in the governing *** assumption of zero nanoparticle flux on the surface makes the model physically more *** the revised model,the dimensionless heat transfer rates are found to be higher whereas the dimensionless mass transfer rates are identically zero due to the passive boundary *** is also found that the Brownian motion parameter has a negligible effect on the Nusselt number.

关键词： stretching Brownian dimensionless revised identically governing realistic physically electrically negligible

High power supercontinuum generation by dual-color femtosecond laser pulses in fused silica

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Chinese Physics B 2022年第8期31卷 436-439页

作者： Saba zafar Dong-Wei Li Acner Camino Jun-Wei Chang Zuo-Qiang Hao Shandong Provincial Engineering and Technical Center of Light Manipulation&Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China Department of Physics Women University MardanMardan 23200Pakistan School of Science Changchun University of Science and TechnologyChangchun 130022China

High power supercontinuum(SC) is generated by focusing 800 nm and 400 nm femtosecond laser pulses in fused silica with a microlens array. It is found that the spectrum of the SC is getting broader compared with the case of a single laser pulse, and the spectral energy density between the two fundamental laser wavelengths is getting significantly higher by optimizing the phase matching angle of the BBO. It exceeds μJ/nm over 490 nm range which is from 380 nm to 870 nm,overcoming the disadvantage of relative lower power in the ranges far from the fundamental wavelength.

关键词： filamentation supercontinuum generation microlens array

Structure and Thermal Parameters of Ni_(20)Pd_(80) Alloy

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Journal of Materials Science & Technology 2009年第2期25卷 208-210页

作者： S. Ahmad A.B. Ziya A. Aziz Z.I. zafar Department of Physics Bahauddin Zakariya University Department of Chemistry Bahauddin Zakariya University

The structure and thermal parameters of Ni20Pd80 alloy were studied by X-ray diffraction（XRD）. The diffraction experiments performed in the temperature range of 308-1100 K revealed that the alloy formed a face centered cubic （fcc） Al-type structure. The temperature dependence of the lattice parameters was investigated by using the Bragg line displacement method showing that the lattice parameter increases with the increase of temperature. The mean linear thermal expansion （MLTE（%））, coefficient of thermal expansion （CTE, α）, the characteristic Debye temperature （（θD） and mean square amplitudes of vibration were determined from XRD data. The value of Debye temperature was found to be 253 K. It was found that temperature factor was independent of the static displacements.

关键词： Alloys Structure Thermal parameters X-ray diffraction (XRD)

Properties of Chemically Synthesized Nano-geopolymer Cement based Self-Compacting Geopolymer Concrete(SCGC)

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Journal of Wuhan University of Technology(Materials Science) 2019年第1期34卷 98-106页

作者： Muhammad Ali Sikandar Byung Wan Jo zafar Baloch Muhammad Asad Khan Department of Civil and Environmental Engineering Hanyang University Department of Civil and Environmental Engineering CECOS University

The physical and mechanical properties of self-compacting geopolymer concrete(SCGC) using chemically synthesized nano-geopolymer cement was investigated. Nano-geopolymer cement was synthesized using nano-silica, alkali activator, and sodium aluminate in the laboratory. Subsequently, nine nanogeopolymer cement sbased SCGC mixes with varying nano-geopolymer cement content, alkali activator content, coarse aggregate(CA) content, and curing temperature were produced. The workability-related fresh properties were assessed through slump flow diameter and slump flow rate measurements. Mechanical performances were evaluated through compressive strength, splitting tensile strength, and modulus of elasticity measurements. In addition, rapid chloride penetration test, water absorption, and porosity tests were also performed. It was assessed that all mix design parameters influenced the fresh and hardened properties of SCGC mixes. Based on test results, it was deduced that nano-geopolymer cement SCGC performed fairly well. All the SCGC mixes achieved the 28-day compressive strength in the range of 60-80 MPa. Additionally, all mixes attained 60% of their 28-day strength during the first three days of elevated temperature curing. FTIR and SEM analyses were performed to evaluate the degree of polymerization and the microstructure respectively for SCGC mixes.

关键词： geopolymer compressive strength self-compacting concrete alkali activator nano-silica

Implication of 14-3-3ζ-BDNF pathway in long-lasting memory enhancement and the rescue from memory deficits

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Neural Regeneration Research 2022年第12期17卷 2685-2686页

作者： Mariam Masmudi-Martín Irene Navarro-Lobato zafar U.Khan Brain Metastasis Group National Cancer Research Centre(CNIO)MadridSpain Donders Institute for Brain Cognition and Behaviour Radboud UniversityNijmegenThe Netherlands Laboratory of Neurobiology CIMESUniversity of MalagaMalagaSpain Department of Medicine Faculty of MedicineUniversity of MalagaMalagaSpain CIBERNED Institute of Health Carlos ⅢMadridSpain

Intact memory function is critical for carrying out daily life activities,such as managing finances,remembering to take medications,driving in familiar environments,remembering a grandchild’s birthday,and learning to use a new ***,memory deficits not only accompany normal aging but are also comorbid with many psychiatric,neurological,and neurodegenerative *** disability,autism,attention deficit disorder,learning disability,schizophrenia,and depression all have memory deficit components,as do Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and other neurodegenerative diseases(Khan et al.,2014).Therefore,a large proportion of the human population is affected by this brain disorder.

关键词： Huntington remember finance