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CES Transactions on Electrical Machines and Systems 2024年第4期8卷 404-413页

作者： Mahmoud-Reza Kheiri arash kiyoumarsi Hasan Zamani Department of Electrical Engineering University of IsfahanIsfahan ***Iran

In this manuscript,a new axial-flux permanentmagnet machine(AFPMM)is designed,analyzed,improved,and successfully tested.A double-sided AFPM generator with four layers of stator winding is initially designed using a well-known quasi-3D analytical ***,the designed machine is simulated using commercial *** is shown that modification techniques are required to improve the performance of both the torque ripple and the ratio of the third to the fundamental harmonics of the induced ***,a new improvement technique is proposed,in which the layers of the stator winding are shifted relative to each *** this new technique significantly improves the third harmonic problem,the design still has a high torque ripple and,thus,it is suggested to combine the proposed method with the conventional magnet shifting *** is revealed numerically that the resulting combination properly resolves both third harmonic and torque ripple ***,this design is considered the main design of the present *** the end,a prototype of the main design is manufactured and *** is shown that the measurement results are in good agreement with those of numerical software.

关键词： Axial-flux permanent-magnet(AFPM)machines Third-harmonic reduction Torque ripple reduction

Five-phase Synchronous Reluctance Machines Equipped with a Novel Type of Fractional Slot Winding

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CES Transactions on Electrical Machines and Systems 2024年第3期8卷 264-273页

作者： S.M.Taghavi Araghi A.kiyoumarsi B.Mirzaeian Dehkordi Department of Electrical Engineering Faculty of EngineeringUniversity of IsfahanIsfahanIran

Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ***,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill *** five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive ***,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core *** manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.

关键词： Finite element analysis Five-phase machine Fractional slot concentrated winding(FSCW) Machine slot/pole combination MMF harmonics Synchronous reluctance machine Winding factor

Right Lateral Shear and Rotation in the Northeast of the Arabian-Iranian Collision Zone

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Journal of Earth Science 2018年第3期29卷 616-628页

作者： arash Barjasteh Deputy for Dam and Power Plant Development Khuzestan Water and Power Authority

Accommodation of continental convergence by crustal thickening and lateral transport is mainly featured as strike-slip faulting along the trends roughly orthogonai to the orientation of plate convergence. This style of faulting will affect seismicity of the involving areas which can be proved in low seismic zones by determining regional stress pattern using numerical methods. Accordingly, the stress distribution and deformation pattern of the South Sanandaj-Sirjan zone in the northeastern part of the Iranian-Arabian collision zone is investigated here using a three dimen-sional mechanical model. The modeled area is bounded between the Zagros thrust fault on the west and Dehshir-Baft fault in the east. The model is composed of three layers： the upper two layers represent the upper brittle and lower ductile crust of the collided continent and the lowest layer represents the lithospheric mantle. The upper crust behaves as an elastic material while the lower crust is considered as a non-Newtonian viscous fluid layer. The lithospheric mantle is taken as a low-viscosity material which is not allowed to move in any direction relative to the overlying layers. The Zagros thrust fault was treated with two different dip values saying 90° and 45° but Dehshir-Baft fault was modeled as a vertical fault and allowed to have a dextral movement regarding to the existing evidence. The driving mechanism applied to the western side of the model was chosen considering two different approaches including a kinematic approach （the Arabian-Eurasian convergence velocity; 35 mm/yr） and a dynamic approach （an external boundary force equal to 3.55E＋17 N）. The resulted stress field indicates an orogen-parallel component of right lateral shear along the Zagros fault implying a rotational deformation pattern within the modeled region that suggests a stress partitioning in the study area. The pattern also indicates a stress accumulation towards the south which could be a reason for the regional seis

关键词： Zagros thrust fault Sanandaj-Sirjan belt numerical modeling shear zone Eghlid-Deh Bid.

Enhancing durability of 3D printed polymer structures by metallization

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Journal of Materials Science & Technology 2020年第18期52卷 185-191页

作者： arash Afshar Dorina Mihut School of Engineering Mercer UniversityMaconGA 31207USA

Additive manufacturing or three dimensional(3D)printing is a promising technique for producing complex geometries and high precision structures from various types of *** technique was particularly developed for polymer materials such as acrylonitrile–butadiene–styrene(ABS)and found its way to different industries such as aerospace,automotive,electronics,medicine and ***,during service in outdoor environments,3D printed polymer structures are exposed to different environmental conditions such as UV radiation and moisture,causing a significant degradation in the microstructure and mechanical properties of the *** study offers a novel method to improve durability of 3D printed polymer structures against accelerated environmental conditions by deposition of a metallic thin film(***)on the structural *** specimens are 3D printed using fused deposition modeling(FDM)technique and metalized via DC magnetron *** characterization of durability of 3D printed ABS specimens in outdoor environments is carried out by monitoring flexural properties and microstructure of samples over the course of exposure in a controlled environmental chamber.

关键词： Fused deposition modeling ABS Environmental exposure Copper thin film DC magnetron sputtering

Dielectric microspheres enhance microscopy resolution mainly due to increasing the effective numerical aperture

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Light(Science & Applications) 2023年第1期12卷 17-19页

作者： arash Darafsheh Vahid Abbasian Department of Radiation Oncology Washington University School of Medicine in St.LouisSt.LouisMO 63110USA

Microsphere-assisted microscopy utilizing a microsphere in immediate proximity of the specimen boosts the imaging resolution mainly as a result of an increase in the effective numerical aperture of the system.

关键词： resolution numerical utilizing

Recent advances in thin film composites membranes for brackish groundwater treatment with critical focus on Saskatchewan water sources

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Journal of Environmental Sciences 2019年第7期31卷 181-194页

作者： arash Mollahosseini Amira Abdelrasoul Department of Chemical and Biological Engineering University of Saskatchewan Global Institute of Water Security

Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations(pesticides,herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their *** is followed by a discussion of Saskatchewan's groundwater status and various ***, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.

关键词： Thin film composite membrane Groundwater Brackish water Water pollution Polyamide Canada Saskatchewan

Buckling analysis of functionally graded plates partially resting on elastic foundation using the differential quadrature element method

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Acta Mechanica Sinica 2019年第1期35卷 174-189,I0005页

作者： arash Shahbaztabar Koosha Arteshyar Department of Ocean Engineering AmirKabir University of TechnologyTehran 15914Iran Department of Mechanical Engineering Islamic Azad UniversityKarajAlborzIran

We extend the differential quadrature element method (DQEM) to the buckling analysis of uniformly in-plane loaded functionally graded (FG) plates fully or partially resting on the Pasternak model of elastic support. Material properties of the FG plate are graded in the thickness direction and assumed to obey a power law distribution of the volume fraction of the constituents. To set up the global eigenvalue equation, the plate is divided into sub-domains or elements and the generalized differential quadrature procedure is applied to discretize the governing, boundary and compatibility equations. By assembling discrete equations at all nodal points, the weighting coefficient and force matrices are derived. To validate the accuracy of this method, the results are compared with those of the exact solution and the finite element method. At the end, the effects of different variables and local elastic support arrangements on the buckling load factor are investigated.

关键词： Differential quadrature element method Pasternak elastic support Critical buckling load Functionally graded plates

Maximizing the potential applications of plasma electrolytic oxidation coatings produced on Mg-based alloys in anti-corrosion,antibacterial,and photocatalytic targeting through harnessing the LDH/PEO dual structure

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Journal of Magnesium and Alloys 2024年第7期12卷 2674-2694页

作者： Elham Nikoomanzari arash Fattah-alhosseini Department of Materials Engineering Faculty of EngineeringBu-Ali Sina UniversityHamedanIran

There is an increasing interest in the development of Mg alloys,both for industrial and biomedical applications,due to their favorable characteristics such as being lightweight and ***,the inadequate corrosion resistance and lack of antibacterial properties pose significant challenges in the industrial and biomedical applications,necessitating the implementation of advanced coating engineering *** electrolytic oxidation(PEO)has emerged as a preferred coating technique because of its distinctive properties and successful surface modification ***,there is a continuous need for further enhancements to optimize the performance and functionalities of protective surface *** integration of layered double hydroxide(LDH)into PEO coatings on Mg alloys presents a promising approach to bolstering protective *** thorough review delves into the latest developments in integrating LDH into PEO coatings for corrosion-related *** particularly emphasizes the significant improvements in corrosion resistance,antibacterial effectiveness,and photocatalytic performance resulting from the incorporation of LDH into PEO *** two key mechanisms that enhance the corrosion resistance of PEO coatings containing LDH are the anion exchangeability of the LDH structure and the pore-sealing ***,the antibacterial activity of PEO coatings with LDH stemmed from the release of antibacterial agents stored within the LDH structure,alterations in pH levels,and the photothermal conversion ***,by incorporating LDH into PEO coatings,new opportunities emerge for tackling environmental issues through boosted photocatalytic properties,especially in the realm of pollutant degradation.

关键词： Mg alloy PEO LDH Corrosion Antibacterial activity Photocatalytic degradation

Effect of glycine-starch mixing ratio on the structural characteristics of MgAl2O4 nano-particles synthesized by sol-gel combustion

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Particuology 2016年第1期14卷 108-112页

作者： arash Motevalian Shiva Salem Faculty of Chemical Engineering Urrnia University of Technology Urrnia lran

Sol-gel auto-ignition was used to prepare nano-scale magnesium aluminate spinel, using nitrate salts as an oxidizer and glycine-starch mixtures as the fuel. The glycine-starch mixture was varied to understand the effect of fuel mixing ratio on the structural characteristics of the resulting magnesium aluminate. The products were characterized by thermogravimetric-differential thermal analyses, Fourier-transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurements, and trans- mission electron microscopy. The phase purity and crystallite size of the powder products depended on the fuel mixing ratio. The presence of starch in the fuel facilitated the preparation of pure nano-particles. To prepare nano-particles of uniform spherical morphology and diameter of 〈 13 nm, the starch content should be Ol^timized to avoid agglomeration.

关键词： MgAl2O4 Starch Sol-gel Combustion Nano-particle Agglomeration

Free vibration analysis of non-homogeneous orthotropic plates resting on Pasternak elastic foundation by Rayleigh-Ritz method

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Journal of Central South University 2016年第2期23卷 413-420页

作者： Ahmad Rahbar-Ranji arash Shahbaztabar Department of Ocean Engineering Amir Kabir University of Technology

Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonalization procedure and adopted in the Rayleigh-Ritz method. Accuracy and applicability of the method are examined by comparison of the results for different boundary conditions and material types with those available in literature. It is found that this method has good accuracy regardless of type of boundary condition and yields very accurate results even with low number of terms of orthogonal polynomials for the first mode of vibration. For higher modes of vibration, higher terms of orthogonal polynomials should be used. The effects of foundation parameter, density and non-homogeneity parameters on natural frequency are examined. It is concluded that natural frequency of plates are more sensitive to shearing layer coefficient rather than Winkler coefficient and density parameter has weakening effect on natural frequency.

关键词： free vibration non-homogeneous orthotropic plate Pastemak foundation Rayleigh-Ritz method Gram-Schmidt procedure