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Effect of porosity on active damping of geometrically nonlinear vibrations of a functionally graded magneto-electro-elastic plate

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Defence Technology（防务技术） 2022年第6期18卷 891-906页

作者： L.sh Esayas Subhaschandra Kattimani Department of mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This paper investigates the effect of porosity on active damping of geometrically nonlinear vibrations(GNLV)of the magneto-electro-elastic(mEE)functionally graded(FG)plates incorporated with active treatment constricted layer damping(ATCLD)*** perpendicularly/slanted reinforced 1-3 piezoelectric composite(1-3 PZC)constricting *** constricted viscoelastic layer of the ATCLD is modeled in the time-domain using Golla-Hughes-mc Tavish(GHm)*** types of porosity distribution in the porous magneto-electro-elastic functionally graded PmEE-FG plate graded in the thickness *** the coupling effects among elasticity,electrical,and magnetic fields,a three-dimensional finite element(FE)model for the smart PmEE-FG plate is obtained by incorporating the theory of layer-wise shear *** geometric nonlinearity adopts the von K arm an *** study presents the effects of a variant of a power-law index,porosity index,the material gradation,three types of porosity distribution,boundary conditions,and the piezoelectric fiber’s orientation angle on the control of GNLV of the PmEE-FG *** results reveal that the FG substrate layers’porosity significantly impacts the nonlinear behavior and damping performance of the PmEE-FG plates.

关键词： Nonlinear vibration magneto-electro-elastic(mEE)plates Active treatment constricted layer damping(ATCLD) Porosity distribution Porous functionally graded

Natural Convection of a Power-Law Nanofluid in a Square Cavity with a Vertical Fin

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Fluid Dynamics & materials Processing 2024年第9期20卷 2091-2108页

作者： Amira m’hadbi mohammed El Ganaoui Haïkel Ben Hamed Amenallah Guizani Khalid Chtaibi LERmAB Department of Transition and Energy Efficiency ProfessionsIUT H Poincaréde LongwyUniversity of LorraineLongwy54400France LPT Center for Energy Research and Technologies(Borj Cedria2084)University of Tunis El ManarTunis1068Tunisia LTI Department of Mechanical Engineering and ProductionIUTUniversity of Picardie Jules-VerneAmiens80025France

The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated *** particular,the impact of nanofluids,composed of water and Al_(2)O_(3),TiO_(2),and Cu nanoparticles,on heat transfer enhancement is *** aim of this research is also to analyze the influence of different parameters,including the Rayleigh number(Ra=10^(4)-10^(6)),nanoparticle volume fraction(φ=0%-20%),non-Newtonian power-law indexes(n=0.6-1.4),and fin dimensions(Ar=0.3,0.5,and 0.7).Streamlines and isotherms are used to depict flow and related heat transfer *** indicate that thermal performance improves with increasing Rayleigh number,regardless of the nanoparticle type or nanofluid rheological *** suggests that the buoyancy force has a significant impact on heat transfer,particularly near the heat *** Nusselt number is more sensitive to variations in Cu nanoparticle volume fractions compared to Al₂O₃and TiO₂.moreover,the average Nusselt numbers for power-law nanofluids with n1)are greater(smaller)than for Newtonian fluids due to the decrease(increase)in viscosity with increasing(decreasing)shear rate,at the same values of Rayleigh number Ra owing to the amplification(attenuation)of the convective ***,the most substantial enhancement is observed with Cu-water shear-thinning nanofluid,where the Nusselt number increases by 136%when changing from Newtonian to shear thinning behavior and by 154.9%when adding 16%nanoparticle volume ***,an even larger increase of 57%in the average Nusselt number is obtained on increasing the fin length from 0.3 to 0.7.

关键词： Heat transfer nanofluid non-Newtonian fluid natural convection

Influences of substrate temperature on microstructure and corrosion behavior of APS Ni_(50)Ti_(25)Al_(25) inter-metallic coating

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Chinese Physics B 2018年第2期27卷 607-612页

作者： sh Khandanjou m Ghoranneviss sh Saviz m Reza Afshar Plasma Physics Research Center Science and Research Branch Islamic Azad University Department of materials Engineering Science and Research Branch Islamic Azad University

In the present investigation, Ni_（50）Ti_（25）Al_（25）（at.%） mechanically alloyed powder is deposited on carbon steel *** the coating process, the substrate is heated to temperature ranging from room temperature to 400℃. The microstructure, porosity, microhardness, adhesion strength, and corrosion behavior of the coating are investigated at different substrate temperatures. Results show that coating porosity is lower on high temperature surface. microhardness and adhesion strength of the deposition layer on the substrate without preheating have lower values than with preheating. The polarization test result shows that corrosion performance of the coating is dependent on micro cracks and porosities and the increasing of substrate temperature can improve the quality of coating and corrosion performance.

关键词： Ni50Ti25Al25 coating air plasma spray planetary ball milling inter-metallic compounds corrosion resistance

Thermo-economic analysis of the performance of the combined system with evacuated tube collectors

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Clean Energy 2023年第2期7卷 242-252页

作者： Ghassan Fadhil Smaisim Salema K.Hadrawi Azher m.Abed Hasan sh.majdi Ali shamel Department of mechanical Engineering Faculty of EngineeringUniversity of Kufa54001Iraq Nanotechnology and Advanced materials Research Unit(NAmRU) Faculty of EngineeringUniversity of Kufa54001Iraq Refrigeration and Air-conditioning Technical Engineering Department College of Technical EngineeringThe Islamic UniversityNajaf54001Iraq Computer Engineering Department Imam Reza UniversityMashhadIran Department of Air Conditioning and Refrigeration Al-Mustaqbal University CollegeBabylon51001Iraq Department of Chemical Engineering and Petroleum Industries Al-Mustaqbal University CollegeBabylon51001Iraq Department of Chemistry Ardebil BranchIslamic Azad UniversityArdebilIran

Using combined cooling,heat and power systems can be an appropriate substitute for preventing emissions of pollutants and excessive consumption of fossil *** renewable energy in these systems as a source of power generation can be an appropriate substitute for fossil-fuel-based ***,in this paper,cogeneration cooling,heat and power systems based on gas-fired internal combustion engines with a solar-thermal system with evacuated tube collectors have been modelled and thermo-economic analysis has been done to compare fossil-fuel-based *** required rate of heat to supply the hot water is 50 *** the studied system,the internal combustion engine produces electrical ***,the solar-thermal system with evacuated tube collectors and the gas-burning generator provide the thermal energy required by the studied building and the primary stimulus of the absorption chiller for *** this study,two different scenarios are conducted in states considering simultaneous production systems and regardless of this environmental and thermo-economic analysis *** results showed that the efficiency of the studied system was 60% in summer and 56% in winter.

关键词： combined cooling,heat and power thermo-economic analysis evacuated tube collectors environmental analysis solar-thermal energy

Preparation and Characterization of Some Ferrites from CuO-ZnO-Fe_2O_3 mixtures

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Journal of materials Science & Technology 1998年第3期14卷 236-240页

作者： A.A.Hanna H.I Saleh and m.sh.khalil(Inorg. Chem. Dept., National Research Centre, Dokki, Cairo, Egypt) Inorg. Chem. Dept. National Research Centre Dokki Cairo Egypt

The ferrites of Cuo-ZnO-Fe2o3 solid solution series near the molar ratio of ZnxCu1-x were prepared by direct heating of their coprecipitated hydroxides using NH4OH as precipitating agent where x=0.0, 0.2, 0.5, 0.8 and 1.0. Additional amounts of Cu and Zn sulphates were added to compensate the loss during the coprecipitation of the hydroxides. The ferritized samples were characterized by chemical analysis, XRD. DTA, TGA and SEm. XRD of both Zn0.2Cu0.8Fe2O4 and Zn0.5Cu0.5 Fe2O4 that indicates the formation of a heterogeneous ferrite material of ZnFe2O4 and CuFe2O4 mixed with variable amounts of α-Fe2O3. Zn and Cu ferrites were observed only in *** TGA-time relation, the activation energy of the different transformation phases were calculated. It is found that, the activation energy of ZnFe2O4 is slightly equal to 3/2 of that for CuFe2O4. Dielectric measurements show that the electrical behaviour depends on the ordering and disordering of the phases.

关键词： CuO ZnO Fe Preparation and Characterization of Some Ferrites from CuO-ZnO-Fe2O3 mixtures

modelling and optimization of combined heat and power system in microgrid based on renewable energy

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Clean Energy 2023年第4期7卷 735-746页

作者： Ghassan F.Smaisim Azher m.Abed Salema K.Hadrawi Hasan sh.majdi Ali shamel Department of mechanical Engineering Faculty of EngineeringUniversity of Kufa54001Iraq Nanotechnology and Advanced materials Research Unit(NAmRU) Faculty of EngineeringUniversity of Kufa54001Iraq Air Conditioning and Refrigeration Techniques Engineering Department Al-Mustaqbal University CollegeBabylon51001Iraq Refrigeration and Air-conditioning Technical Engineering Department College of Technical EngineeringThe Islamic UniversityNajafIraq Department of Chemical Engineering and Petroleum Industries Al-Mustaqbal University CollegeBabylon 51001Iraq Department of Chemistry Ardebil BranchIslamic Azad UniversityArdebilIran

Due to the short distance between the sources of production and consumption,microgrids(mGs)have received considerable attention because these systems involve fewer losses and waste less *** another advantage of mGs is that renewable energy sources can be widely used because these resources are not fully available and can provide a part of the required *** purpose of this research is to model the mG considering the production sources of microturbines,gas turbines and internal combustion *** energies such as wind turbines(WTs)and photovoltaic(PV)cells have been used to provide part of the required power and,because of the lack of access to renewable energy sources at all times,energy reserves such as batteries and fuel cells(FCs)have been *** power of the microturbine,gas turbine,internal combustion engine,FC and battery in this system is 162,150,90,100 and 225 kW,*** modelling the studied system,optimization was done using the imperialist competitive algorithm to minimize production costs and provide maximum thermal and electrical *** maximum production power for PVs is equal to 0.6860 mWh and at this time this value for WTs is equal to 0.3812 mWh,in which case the excess electricity produced will be sold to the grid.

关键词： microgrid energy management system optimization optimal power flow combined heat and power sustainable development

Solving two-dimensional Volterra-Fredholm integral equations of the second kind by using Bernstein polynomials

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Applied mathematics(A Journal of Chinese Universities) 2017年第1期32卷 68-78页

作者： m.sh.Dahaghin sh.Eskandari Department of mathematics Shahrekord University Shahrekord Iran

In this paper, we present a numerical method for solving two-dimensional VolterraFredholm integral equations of the second kind（2DV-FK2）. Our method is based on approximating unknown function with Bernstein polynomials. We obtain an error bound for this method and employ the method on some numerical tests to show the efficiency of the method.

关键词： Volterra approximating approximate variational proof iterative uniformly exact wavelet inequality

Corrosion protection and mechanical properties of the electroless Ni-P-mOF nanocomposite coating on Am60B magnesium alloy

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Journal of magnesium and Alloys 2022年第8期10卷 2280-2295页

作者： Z.Rajabalizadeh D.Seifzadeh A.Khodayari sh.Sohrabnezhad Applied Chemistry Department University of Mohaghegh ArdabiliArdabil ***Iran Department of Chemistry Faculty of ScienceUniversity of GuilanP.O.Box 1914RashtIran

Al-based mIL-53 mOF nanostructure was synthesized hydrothermally and then co-deposited in the electroless nickel coating on Am60B magnesium alloy using Zr pretreatment as an eco-friendly *** mIL-53(Al)nanostructure was synthesized in the form of layered semi-cube crystals with the surface area and mean pore diameter of 985.72 m^(2)g^(-1) and 2.00 nm,*** SEm images captured with two various zooming scales from the surface of the plain and mOF containing electroless layers showed cauliflower-like morphology with even distribution of nodule ***,the sub-grains of the plain coating disappeared after incorporation of the ***,both the normal and nanostructure-containing electroless layers have crystalline-amorphous structure,but the nanocomposite coating showed less *** average surface roughness of the plain electroless coating was about 309 nm,which decreased to about 222 nm after incorporation of the *** XRD patterns showed that the characteristic peak of Ni broadened after incorporation of the mOF,probably due to the decreasing of the *** the heat-treated normal and mOF containing coatings at 200℃ no phase transition takes place,but new peaks appeared for heat-treated coatings at 400℃ due to the crystallization and second-phase *** results of the EIS tests showed an increase in the amount of the charge transfer resistance(from 19 to 29 kΩcm^(2))after addition of the mOF,which means an improvement in the corrosion ***,low Jcorrof the composite coating represents its higher corrosion resistance with respect to the plain *** micro-hardness values of the composite coating before and after the heat treatment were higher than the plain ***,the Ni-P-mOF coating has a lower wear rate both before and after the heat treatment due to an improvement in its micro-hardness.

关键词： Electroless plating mOF magnesium alloy Wear EIS

Kerosene-alumina nanofluid flow and heat transfer for cooling application

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Journal of Central South University 2016年第4期23卷 983-990页

作者： m.mahmoodi sh.Kandelousi Department of Aerospace Engineering Malek-Ashtar University of Technology Department of mechanical Engineering Babol University of Technology

Kerosene-alumina nanofluid flow and heat transfer in the presence of magnetic field are studied. The basic partial differential equations are reduced to ordinary differential equations which are solved semi analytically using differential transformation method. Velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number are determined analytically. The influence of pertinent parameters such as magnetic parameter, nanofluid volume fraction, viscosity parameter and Eckert number on the flow and heat transfer characteristics is discussed. Results indicate that skin friction coefficient decreases with increase of magnetic parameter, nanofluid volume fraction and viscosity parameter. Nusselt number increases with increase of magnetic parameter and nanofluid volume fraction while it decreases with increase of Eckert number and viscosity parameter.

关键词：流体流动纳米流体氧化铝煤油 Nusselt数常微分方程应用冷却