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Acta mechanica Sinica 2018年第3期34卷 507-514页

作者： Z.m.Zheng b.Wang School of Physics Sun Yat-Sen UniversityGuangzhou 510275China Instimt Franco-Chinois de l'Energie Nucleaire Sun Yat-Sen UniversityZhuhai 519000China

Conventional heat transfer fluids usually have low thermal conductivity, limiting their efficiency in many applications. many experiments have shown that adding nanosize solid particles to conventional fluids can greatly enhance their thermal conductivity. To explain this anomalous phenomenon, many theoretical investigations have been conducted in recent years. Some of this research has indicated that the particle agglomeration effect that commonly occurs in nanofluids should play an important role in such enhancement of the thermal conductivity, while some have shown that the enhancement of the effective thermal conductivity might be accounted for by the structure of nanofluids, which can be described using the radial distribution function of particles. However, theoretical predictions from these studies are not in very good agreement with experimental results. This paper proposes a prediction model for the effective thermal conductivity of nanofluids, considering both the agglomeration effect and the radial distribution function of nanoparticles. The resulting theoretical predictions for several sets of nanofluids are highly consistent with experimental data.

关键词： Nanofluid Thermal conductivity modeling Agglomeration Radial distribution function

mechanical properties of thixo-formed austempered ductile iron

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中国有色金属学会会刊：英文版 2010年第S3期20卷 798-804页

作者： b.HEIDARIAN m.NLILI-AHmADAbADI m.mORADI School of metallurgy and materials Engineering University of Tehran

Semi-solid processing of metallic materials has been investigated for some time;however,this innovative production process has not fully established for ferrous alloys like ductile cast iron in the industry *** alloys-specially ductile cast ironbecause of increasing complexity due to high temperature processing and some other limitations have been allocated a small share of this useful forming process to ***,this work describes that thixo-forming of ductile iron despite all of the limitations is possible even for thin sections(less than 1 mm).Die temperature and injection velocity are the most effective parameters to thixo-forming particularly for high melting point materials such as ductile cast *** behavior,shape factor of graphites and fluidity of thixo-formed specimens were *** addition,defects as well as shrinkage and cold laps were examined to achieve sound *** to successful thixo-forming,two step austempering was performed to accomplish a uniform structure with minimum untransformed austenite volume(UAV).Following austempering,tensile test was carried out and the results show good combination of tensile strength and elongation for treated specimens(1 137 mPa strength and 12% elongation in best situation).

关键词： semi-solid ductile iron high pressure mold filling segregation mechanical properties

Practical optimization of deployable and scissor-like structures using a fast GA method

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 557-568页

作者： m.SALAR m.R.GHASEmI b.DIZANGIAN Department of Civil Engineering University of Sistan and BaluchestanZahedanIran Department of Civil Engineering Velayat UniversityIranshahrIran

This paper addresses practical sizing optimization of deployable and scissor-like structures from a new point of *** structures have been recently highly regarded for beauty,lightweight,determine behavior,proper performance against lateral loads and the ability of been compactly *** this time,there is a few studies done considering practical optimization of these *** considered here includes wind and gravity *** foldable scissor-like structures,connections have a complex *** this reason,in this study,the authors used the AbAQUS commercial package as an analyzer in the optimization *** made the obtained optimal solutions highly reliable from the point of view of applicability and construction ***,to do optimization task,a fast genetic algorithm method,which has been recently introduced by authors,was *** results show that despite less weight for aluminum models than steel models,aluminum deployable structures are not affordable because they need more material than steel structures and cause more environmental damage.

关键词： optimization scissor-like structures deployable structures genetic algorithm AbAQUS

mixed convection characteristics in lid-driven cavity containing heated triangular block

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Chinese Journal of Chemical Engineering 2017年第10期25卷 1381-1394页

作者： Krunal m.Gangawane b.manikandan Department of Chemical Engineering University of Petroleum and Energy Studies Dehradun 248007 Uttrakhand India

This research work numerically analyzes 2D,steady state,mixed convective heat transfer for Newtonian fluids in lid driven square enclosure with centered triangular block（blockage—10%or 30%）maintained either at the constant wall temperature or constant heat flux thermal *** fluid flow in the enclosure is initiated by top moving wall in＋x-direction,while all other walls are *** top and bottom walls are thermally *** particular,the governing field equations are solved for range of governing parameters such as,Reynolds number（1–1000）,Prandtl number（1–100）,and Grashof number

关键词： mixed convection Lid-driven cavity Reynolds number Numerical study Grashof number

Characterization of ion irradiated silicon surfaces ablated by laser-induced breakdown spectroscopy

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Chinese Physics b 2018年第8期27卷 505-510页

作者： T Iqbal m Abrar m b Tahir m Seemab A majid S Rafique Department of Physics Faculty of Sciences University of Gujrat Hafiz Hayat Campus Department of Physics Hazara University Mansehra Department of Physics University of Engineering and Technology (UET)Lahore Pakistan

Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such as electrical, morphological, and structural modifications. Thomson parabola technique is used to calculate the energy of these metallic ions whereas the electrical conductivity is calculated with the help of Four-point probe. Interestingly circular tracks forming chain like damage trails are produced via these energetic ions which are carefully examined by optical microscopy. It is observed that excitation, ionization, and cascade collisions are responsible for surface modifications of irradiated samples. Four-point probe analysis revealed that the electrical conductivity of substrate has reduced with increasing trend of atomic number of irradiated metallic ions （A1, Ti, Cu, and Au）. The x-ray diffraction analysis elucidated the crystallographic changes leading to reduction of grain size of N-type silicon substrate, which is also associated with the metallic ions used. The decreasing trend of conductivity and grain size is due to thermal stresses, scattering effect, structural imperfections, and non-uniform conduction of energy absorbed by substrate atoms after the ion irradiation.

关键词： ablation Thomson parabola technique four-point probe

mETHOD OF mOmENT EXCITATION IN TESTING OF STRUCTURES

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Acta mechanica Solida Sinica 1995年第3期8卷 277-282页

作者： b.m.Gibbs Acoustics Research Unit Liverpool University P.O.Box 147Liver pool L69 3BXU.K.

The method of the moment excitation in the studies of the structure-borne sound using a moment actuator is introduced. Some design considerations for the moment actuator are presented. A standard mechanical system is established to calibrate the performance of the moment actuator. The frequency and mechanical power performances of the actuator are discussed.

关键词： mOmENT ACTUATOR ANALOGOUS CIRCUIT CROSS-SPECTRUm mETHOD

Effect of periodic heat transfer on the transient thermal behavior of a convective-radiative fully wet porous moving trapezoidal fin

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Applied mathematics and mechanics(English Edition) 2023年第4期44卷 653-668页

作者： b.J.GIREESHA m.L.KEERTHI Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India

A moving trapezoidal profiled convective-radiative porous longitudinal fin wetted in a single-phase fluid is considered in the current *** periodic variation in the fin base temperature is taken into account along with the temperature sensitive thermal conductivity and convective heat transfer *** modeled problem,which is resolved into a non-linear partial differential equation(PDE),is made dimensionless and solved by employing the finite difference method(FDm).The results are displayed through graphs and *** effects of amplitude,frequency of oscillation,wet nature,Peclet number,and other relevant quantities on the distribution of temperature through the fin length and with the dimensionless time are *** is deciphered that the periodic heat transfer gives rise to the wavy nature of the fin thermal profile against *** analysis is beneficial in the design of fin structures for applications like solar collectors,space/airborne applications,and refrigeration industries.

关键词： convection fully wet porous fin trapezoidal profile moving fin unsteady periodic thermal condition

microstructural Evolution during Partial Remelting of Al—Si Alloys Containing Different Amounts of magnesium

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Journal of materials Science & Technology 2013年第10期29卷 971-978页

作者： A.Abedi m.Shahmiri b.Amir Esgandari b.Nami Department of mechanical Engineering Shahid Rajaee Teacher Training University (SRTTU) School of metallurgy and materials Science Iran University of Science and Technology (IUST)

The effect of magnesium on the microstructures of A356 aluminum alloy in as-cast and semi-solid conditions was investigated. The result showed that magnesium refined the size of primary α（Al） phase and eutectic silicon. magnesium also modified considerably the eutectic silicon and decreased the size of globular α（Al） solid phase in the semi-solid processed alloy. Coarsening rate of the solid α（Al） phase during partial remelting at semi-solid temperature decreased by adding magnesium, probably due to the decrease of both the solid- liquid interfacial energy and inter-diffusion coefficient of solute atoms.

关键词： Al--Si alloys magnesium microstructure Semi-solid processing Coarsening

Analysis of the Interaction of Pulsed Laser with Nanoporous Activated Carbon Cloth

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Journal of materials Science & Technology 2011年第11期27卷 979-984页

作者： b.V. Kaludjerovi m.S. Trtica b.b. Radak J.m. Stai S.S. Krsti muovi V.m. Dodevski Laboratory of material Science Vina Institute for Nuclear Sciences University of BelgradeP.O. Box 522 11001 Serbia Laboratory of Physical Chemistry Vina Institute for Nuclear Sciences University of BelgradeP.O. Box 522 11001 Serbia

Interaction of pulsed transversely excited atmospheric （TEA） CO2-1aser radiation at 10.6 μm with nanoporous activated carbon cloth was investigated. Activated carbon cloth of different adsorption characteristics was used. Activated carbon cloth modifications were initiated by laser pulse intensities from 0.5 to 28 mW/cm^2, depending on the cloth adsorption characteristics. CO2 laser radiation was effectively absorbed by the used activated carbon cloth and largely converted into thermal energy. The type of modification depended on laser power density, number of pulses, but mostly on material characteristics such as specific surface area. The higher the surface area of activated carbon cloth, the higher the damage threshold.

关键词： Activated carbon cloth Transversely excited atmospheric (TEA) C02 laser Nanoporous material Laser-material interaction

New Soliton Wave Solutions to a Nonlinear Equation Arising in Plasma Physics

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Computer modeling in Engineering & Sciences 2023年第10期137卷 827-841页

作者： m.b.Almatrafi Abdulghani Alharbi Department of mathematics Faculty of ScienceTaibah UniversitySaudi Arabia

The extraction of traveling wave solutions for nonlinear evolution equations is a challenge in various mathematics,physics,and engineering *** article intends to analyze several traveling wave solutions for themodified regularized long-wave(mRLW)equation using several approaches,namely,the generalized algebraic method,the Jacobian elliptic functions technique,and the improved Q-expansion *** successfully obtain analytical solutions consisting of rational,trigonometric,and hyperbolic *** adaptive moving mesh technique is applied to approximate the numerical solution of the proposed *** adaptive moving mesh method evenly distributes the points on the high error *** method perfectly and strongly reduces the *** compare the constructed exact and numerical results to ensure the reliability and validity of the methods *** better understand the considered equation’s physical meaning,we present some 2D and 3D *** exact and numerical approaches are efficient,powerful,and versatile for establishing novel bright,dark,bell-kink-type,and periodic traveling wave solutions for nonlinear PDEs.

关键词： The modified regularized long wave equation soliton solutions plasma physics numerical solutions