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Unsteady three-dimensional MHD flow of the micropolar fluid over an oscillatory disk with Cattaneo-Christov double diffusion

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Applied Mathematics and Mechanics(English Edition) 2019年第10期40卷 1471-1486页

作者： A.RAUF s.A.sHEHZAD Z.ABBAs T.HAYAT Department of Mathematics COMSATS University Islamabad Sahiwal 57000 Pakistan Department of Mathematics The Islamia University of Bahawalpur Bahawalpur 63100 Pakistan Department of Mathematics Quiad-i-Azam University Islamabad 44000 Pakistan

Cattaneo-Christov heat and mass flux models are considered rather than Fourier and Fick laws due to the presence of thermal and concentration transport hyperbolic phenomena. The generalized form of the Navier-stokes model is considered in hydromagnetic flow. Three-dimensional (3D) unsteady fluid motion is generated by the periodic oscillations of a rotating disk. similarity transformations are used to obtain the normalized fluid flow model. The successive over relaxation (sOR) method with finite difference schemes are accomplished for the numerical solution of the obtained partial differential non-linear system. The flow features of the velocity, microrotation, temperature, and concentration fields are discussed in pictorial forms for various physical flow parameters. The couple stresses and heat and mass transfer rates for different physical quantities are explained via tabular forms. For better insight of the physical fluid model, 3D fluid phenomena and two-dimensional (2D) contours are also plotted. The results show that the micropolar fluids contain microstructure having non-symmetric stress tensor and are useful in lubrication theory. Moreover, the thermal and concentration waves in Cattaneo-Christov models have a significance role in the laser heating and enhancement in thermal conductivity.

关键词： three-dimensional (3D) flow micropolar fluid magnetohydrodynamics (MHD) Cattaneo-Christov theory oscillatory disk

Optimization of thermoacoustic refrigerator using response surface methodology

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Journal of Hydrodynamics 2013年第1期25卷 72-82页

作者： HARIHARAN N. M. sIVAsHANMUGAM P. KAsTHURIRENGAN s. Department of Chemical Engineering National Institute of Technology Centre for Cryogenic Technology Indian Institute of Science

Thermoacoustic refrigerator （TAR） converts acoustic waves into heat without any moving parts. The study presented here aims to optimize the parameters like frequency, stack position, stack length, and plate spacing involving in designing TAR using the Response surface Methodology （RsM）. A mathematical model is developed using the RsM based on the results obtained from DeltaEC software. For desired temperature difference of 40 K, optimized parameters suggested by the RsM are the frequency 254 Hz, stack position 0.108 m, stack length 0.08 m, and plate spacing 0.0005 m. The experiments were conducted with optimized parameters and simulations were performed using the Design Environment for Low-amplitude ThermoAcoustic Energy Conversion （DeltaEC） which showed similar results.

关键词： Design Environment for Low-amplitude ThermoAcoustic Energy Conversion (DeltaEC) optimization Response surface Methodology (RsM) temperature difference thermoacoustic refrigerator (TAR)

Review of deployment technology for tethered satellite systems

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Acta Mechanica sinica 2018年第4期34卷 754-768页

作者： B.s.Yu H.Wen D.P.Jin state Key Laboratory of Mechanics and Control of Mechanical structures Nanjing University of Aeronautics and Astronautics

Tethered satellite systems（Tsss） have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a Tss. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. Hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

关键词： Tethered satellite Deployment Dynamics Control Experiment

Electronic structure and magnetic properties of rare-earth perovskite gallates from first principles

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Chinese Physics B 2017年第1期26卷 375-385页

作者： A Dahani H Alamri B Merabet A Zaoui s Kacimi A Boukortt M Bejar Laboratoire de Physique Computationnelle des Materiaux Universite Dfillali Liabes de Sidi Bel-Abbes Sidi Bel-Abbes 22000 Algeria Universite Moulay Tahar Faculte de Technologie Saida 20000 Algeria Umm AI-Qura University Physics Department-University College Makkah Saudi Arabia Universite Mustapha stambouli Faculte de Technologie Mascara 29000 Algeria Elaboration Characterization Physico-Mechanics of Materials and Metallurgical Laboratory ECP3M Faculty of Sciences and Technology Abdelhamid Ibn Badis University of Mostaganem Mostaganem 27000 Algeria Laboratoire de Physique Appliquee Faculte des Sciences Universite de Sfax Sfax 3000 Tunisia

The density functional calculation is performed for centrosymmetric（La–Pm） GaO3 rare earth gallates, using a full potential linear augmented plane wave method with the LsDA and LsDA＋U exchange correlation to treat highly correlated electrons due to the very localized 4f orbitals of rare earth elements, and explore the influence of U = 0.478 Ry on the magnetic phase stability and the densities of states. LsDA＋U calculation shows that the ferromagnetic（FM） state of RGaO3 is energetically more favorable than the anti-ferromagnetic（AFM） one, except for LaGaO3 where the NM state is the lowest in energy. The energy band gaps of RGaO3 are found to be in the range of 3.8–4.0 eV, indicating the semiconductor character with a large gap.

关键词： DFT+U+sO strongly correlated electron systems magnetism rare earth gallates perovskites

Effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids by using the Lord-shulman and dual-phase-lag models

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1135-1154页

作者： s.M.ABO-DAHAB A.M.ABD-ALLA A.A.KILANY Department of Mathematics Faculty of SciencesTaif UniversityTaif 888Saudi Arabia Department of Mathematics Faculty of ScienceSouth Valley UniversityQena 83523Egypt Department of Mathematics Faculty of ScienceSohag UniversitySohag 82524Egypt

The effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids in a generalized thermoplastic half-space are studied by using the Lord-shulman (L-s) model and the dual-phase-lag (DPL) model. The analytical solutions for the displacements, stresses, temperature, diffusion concentration, and volume fraction field with different values of the magnetic field, the rotation, the gravity, and the initial stress are obtained and portrayed graphically. The results indicate that the effects of gravity, rotation, voids, diffusion, initial stress, and electromagnetic field are very pronounced on the physical properties of the material.

关键词： electromagnetic field gravity field rotation initial stress voids diffusion normal mode analysis Lord-shulman (L-s) model dual-phase-lag (DPL) model

Moisture effect on the combustion of a single copper concentrate particle in a flash smelting furnace

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International Journal of Minerals,Metallurgy and Materials 2014年第3期21卷 251-258页

作者： E.Hassan Zaim s.H.Mansouri A.Arab solghar Department of Mechanical Engineering School of Engineering Shahid Bahonar University Department of Mechanical Engineering School of Engineering Vali-e-Asr University

A mathematical model has been presented to study the combustion of a single copper concentrate particle with high moisture content. By using the presented model, the effect of particle moisture content on particle temperature, sulfur oxidation, and combustion heat generation has been evaluated. The mineralogical composition of the commonly used concentrate at Khatoonabad flash smelting furnace has been used in this study. It was found that the particle moisture content is removed in the sub-second time range and thus the moisture has marginal impact on the variation of particle temperature and on the reaction rate when the gas temperature is assumed to be constant in the reaction shaft. When a concentrate with high moisture content is charged, the particle size enlargement due to the agglomeration of concentrate particles causes an abrupt fall in the particle reaction rate.

关键词： flash smelting furnaces copper smelting moisture combustion

Investigation on the dissolution of η phase in a cast Ni-based superalloy

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International Journal of Minerals,Metallurgy and Materials 2013年第1期20卷 42-48页

作者： M.R. Jahangiri H. Arabi s.M.A. Boutorabi school of Metallurgy and Materials Engineering Iran University of Science and Technology Metallurgy Department Niroo Research Institute Center of Excellence for Advanced Materials & Processing Iran University of Science and Technology

The dissolution behavior of rI phase has been investigated in a cast Ni-based superalloy. The results showed that the platelets and blocks of η phase were formed within the interdendritic regions of the microstructure. Applying standard solution annealing at 1150-1160℃ for a period of 4 h did not result in the complete dissolution of η phase. For the complete dissolution of η phase without residual incipient melting, a 2-step solution annealing has been recommended. After dissolution at high tem- peratures, the TI phase transforms to two MC-type carbides： one is enriched in Ti, Nb, and Ta, and the other is of （Zr,Ti）C type.

关键词： superalloys nickel alloys phase transitions dissolution heat treatment carbides

Impact of antibacterial drugs on human serum paraoxonase-1(hPON1)activity:an in vitro study

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Asian Pacific Journal of Tropical Biomedicine 2014年第8期4卷 603-609页

作者： Hakan syt Elif Duygu Kaya skr Beydemir Department of Primary Education Faculty of EducationBayburt University69000 BayburtTurkey Department of Food Engineering Faculty of EngineeringIgdir University76000 lgdirTurkey Department of Chemistry Faculty of ScienceAtatrk University25240 ErzurumTurkey

Objective:To investigate the in vitro effects of the antihacterial drugs,mcropenem *** sodium,and cefoperazone sodium,on the activity of human serum paraoxonase ***:hPQN1 was purified from human serum using simple chromatographic *** DEAE-sephadex anion exchange and sephadex G-200 gel filtration ***:The three antihacterial drugs decreased in vitro hPON1 *** mechanisms meropcnem trihydrate was noncompetitive while piperacillin sodium and cefoperazone sodium were ***:Our results showed that antihacterial drugs significantly inhibit hPON1 activity,both in vitro,with rank order meropenem trihydrate piperacillin sodium cefoperazone sodium in vitro.

关键词： Paraoxonase Inhibition Meropenem trihydrate Piperacillin sodium Cefoperazone sodium

Continuous monitoring of residual water content in boiling waterhydrocarbon emulsions during thermomechanical dehydration

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Chinese Journal of Chemical Engineering 2024年第12期76卷 118-123页

作者： A.safiulina s.Khusnutdinov I.Khusnutdinov I.Goncharova Institute of Petroleum Chemistry and NanotechnologiesKazan National Research Technological University 420015Russia Chair of Mining Engineering and Mineral Economics University of Leoben 4820Austria

significant waste resources are generated in the form of water-oil *** emulsions cannot be effectively destroyed on an industrial scale by traditional methods that rely on the settling of the aqueous phase,and therefore,they accumulate in large *** dehydration,based on the evaporation of the water phase,presents a promising process for recycling such ***,within the framework of thermomechanical dehydration,the issue of optimizing energy costs for heating raw materials and controlling the water content in the product *** methods of determining water content under the boiling conditions of highly stable water-hydrocarbon emulsions are characterized by low efficiency,as they require constant sampling and the involvement of additional equipment and ***,this presents a challenge in predicting and creating an automated thermomechanical dehydration ***,dynamic curves depicting changes in the water content of these emulsions,depending on the temperature of the boiling liquid,have been *** is proposed to determine the rate of temperature increase(dT/dt)of the boiling emulsion for continuous,real-time monitoring of the residual water content and for recording the moment of complete *** a boiling emulsion temperature of 130-170℃(or higher)and/or the rate of temperature increase from 3.0 to 5.5(or above)indicates the complete dehydration of the *** proposed method can be implemented in any industrial or laboratory-scale unit for thermomechanical dehydration without significant capital *** is based on the use of simple devices consisting of temperature sensors and a computing unit for determining the temperature and rate of heating.

关键词： Continuous water content monitoring during thermomechanical evaporation Final dehydration temperature The rate of temperature increase Waste treatment Emulsions Process control