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Diffusion in FsW Joints by Inserting the Metallic Foils

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Journal of Materials science & Technology 2013年第11期29卷 1091-1095页

作者： s.Gholami shiri A.sarani s.r.elmi hosseini G.roudini school of Materials science and Engineering Department of EngineeringShiraz University Department of Materials science & Engineering Faculty of EngineeringUniversity of Sistan and Baluchestan

The aims of this investigation were to study diffusion phenomenon in friction stir welding （FsW） joints and its influence on the tensile strength of joints. To study diffusion in stir zone, various metallic foils were inserted between two pure aluminium plates. The thin foils of pure copper, pure zinc, brass and Cu-Zn-Ni alloy with the thickness of 250 μm were used as metallic foils. The transversal cross sections of welds were observed by optical microscopy and scanning electron microscopy （sEM） equipped with an energy dispersive X-ray spectroscopy （EDs） system. The spot analyses near the metallic foils indicated that diffusion occurs from foils into the aluminium plates during welding; consequently, the strength of stir zone increases even by 50%. Besides, the metallic foils could reveal the flow of metal after FsW process.

关键词： Friction stir welding Diffusion Metallic foil Pure aluminium Tensile strength

A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： s.sAUrABH r.KIrAN D.sINGH r.VAIsH V.s.CHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the C0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(Hr), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

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Influence of soaking time in deep cryogenic treatment on the microstructure and mechanical properties of low-alloy medium-carbon HY-TUF steel

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 658-666页

作者： Ahmad Zare s.r.hosseini Department of Materials Engineering Maleke-ashtar University of Technology

The influence of soaking time in deep cryogenic treatment on the tensile and impact properties of low-alloy medium-carbon HY-TUF steel was investigated in this study. Microstructural studies based on phase distribution mapping by electron backscatter diffraction show that the deep cryogenic process causes a decrease in the content of retained austenite and an increase in the volume fraction of η-carbide with increasing soaking time up to 48 h. The decrease in the content of retained austenite from ~1.23vol% to 0.48vol% suggests an isothermal martensitic transformation at 77 K. The η-type precipitates formed in deep cryogenic-treated martensite over 48 h have the Hirotsu and Nagakura orientation relation with the martensitic matrix. Furthermore, a high coherency between η-carbide and the martensitic matrix is observed by high-resolution transmission electron microscopy. The variations in macrohardness, yield strength, ultimate tensile strength, and ductility with soaking time in the deep cryogenic process show a peak/plateau trend.

关键词： low alloy steel medium carbon steel cryogenic treatment microstructure mechanical properties fractography

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： r.A.JAFArI-TALOOKOLAEI H.GHANDVAr E.JUMAEV s.KHATIr T.CUONG-LE school of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and science Center for Engineering Application and Technology solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANsYs, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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Mixing and segregation of solid particles in a conical spouted bed： Effect of particle size and density

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Particuology 2017年第3期15卷 132-140页

作者： M. Kiani M.r. rahimi s.H. hosseini G. Ahmadi Department of Chemical Engineering Faculty of Engineering Yasouj University Yasouj lran Department of Chemical Engineering Faculty of Engineering llam University Ilam 69715-516 Iran Department of Mechanical and Aeronautical Engineering Clarkson University Potsdam NY 13699-5725 USA

In this work, the mixing and segregation of binary mixtures of particles with different sizes and densities in a pseudo-2D spouted bed were studied experimentally. A binary mixture of solid particles including sand, gypsum, and polyurethane was used. To determine the particles mass fraction, and their mixing and segregation in the bed, an image-processing technique was developed and used. Important hydrodynamic parameters, such as the axial and radial segregation profiles of the solid particles, were measured. The effects of air velocity, particle size, and particle mass fraction were also evaluated. The flow regime in the spouted bed and the time required for reaching the equilibrium state of the solid particles were discussed. The results showed that the segregation of solid particles and the time to equilibrium both decreased when the air velocity increased to much larger than the minimum spouting velocity. The axia! segregation increased with the diameter ratio of the particles. Upon completion of the test, coarse particles were concentrated mainly in the spout region, while fine particles were aggregated in the annulus region. Examination of the flow pattern in the spouted bed showed that the particles near the wall had longer flow paths, while those near the spout region had shorter flow paths.

关键词： Experimental segregation Binary particles 2D spouted bed

A novel control strategy for load converter of DC isolated distribution system under unbalanced loading conditions

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2009年第6期10卷 890-899页

作者： r.NOrOOZIAN M.ABEDI G.B.GHArEHPETIAN s.H.hosseini Department of Electrical Engineering Amirkabir University of Technology Department of Electrical and Computer Engineering Tabriz University

A novel control strategy for the load converter supplying the unbalanced AC load in a DC isolated distribution system is presented. The control algorithm results in balanced and sinusoidal load voltages under unbalanced AC loading. The unbalanced load is characterized in the d-q-0 rotating coordinate based on symmetrical sequence components. Also, the mathematical model of the load converter in both a-b-c and d-q-0 coordinates is derived by using the average large signal model. Then, two control strategies for the load converter are presented. The first one uses the conventional d-q-0 controller to ensure the voltage and current regulation. The second one is a newly proposed control strategy based on the decomposition of the voltage and current into in-stantaneous positive, negative, and zero sequences. These three sequences are controlled independently in their own reference frames as DC signals. The performance of the load converter using these two control strategies is compared. simulation results show the validity and capability of the newly proposed control strategy.

关键词： Unbalanced load Power quality symmetrical components Control strategy

An efficient synthesis of substituted alkyl acrylates using α-keto amides

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Chinese Chemical Letters 2008年第2期19卷 175-179页

作者： r. Baharfar M. Tajbakhsh A. Hamedaninejad s.J. hosseini Department of Chemistry University of Mazandaran P.O. Box 453 Babolsar Iran

The addition of α-keto amides as a NH-acid to alkyl propiolates and dialkyl acetylenedicarboxylates in the presence of a catalytic amount of triphenylphosphine gives the corresponding substituted alkyl acrylates.

关键词： Alkyl propiolate Triphenylphosphine NH-acids Organophosphorus compounds

Effect of tritium reduction in determining energy gain by using r-matrix method direct laser fusion in D-T reaction

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Nuclear science and Techniques 2007年第3期18卷 129-136页

作者： s.N.hosseini MOTLAGH sh.s.MOHAMADY M.Kh.MOrADKHANI r.sHAMsI Department of Physics Iran University of science and Technology IranDepartment of PhysicsIran University of Science and Technology IranDepartment of PhysicsIran University of Science and Technology IranDepartment of Industrial EngineeringMazandaran University of Science and Technology Iran

The laser fusion criterion is known as the ρr-Criterion, also called high-gain condition. This parameter is temperature dependent and can be calculated by r-matrix method. This method is applied for determining improved fusion cross-section for the reactions T(d,n)4He, 3He(d,p)4He, D(d,p)T, D(d,n)3He. In this paper the time dependent reaction rate equations for fusion reaction T(d,n)4He are solved and by using the obtained results we computed the fu- sion power density, energy gain versus temperature and ρr-parameter. The obtained results show that a suitable com- bination may be a deuterium fraction fD=0.65 and fT=0.35 which would lead 30% reduction in the tritium content of the fuel mixture, and this choice would not change the energy gain value very much. Finally, the obtained energy gain for D-T reaction by using r-matrix is in good agreement with other theories.

关键词：氘氚反应激光聚合等离子体交叉断面

Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

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World Journal of Methodology 2025年第1期15卷 20-25页

作者： Nadeesha r samarasinghe Taniya s Nagpal Michele L Barbeau Charys M Martin Division of General surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada Department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are well ***,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary *** investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(MsK)anatomy course *** synchronous sessions were co-taught by a group fitness instructor and an anatomy *** fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving MsK anatomy knowledge,PA levels,and mental *** participants completed surveys;a majority agreed that the classes increased understanding of MsK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw benefit in PA based interventions to supplement MsK course *** with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： Medical education Musculoskeletal Anatomy Exercise Online learning