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Multidisciplinary design optimization of a dual-spin guided vehicle

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Defence Technology（防务技术） 2024年第7期37卷 133-148页

作者： Jalal Karimi Mohammad Reza rajabi Seyed Hossein Sadati Seyed Mahid Hosseini Department of Aerospace Engineering Malek Ashtar University of TechnologyTehranIran

In this research,a Multidisciplinary Design Optimization approach is proposed for the dual-spin guided flying projectile design considering external and internal parts of the body as design *** this way,a parametric formulation is *** related disciplines,including structure,aerodynamics,guidance,and control are *** total mass,maximum aerodynamic control effectiveness,minimum miss distance,maximum yield stress in all subsystems,controllability and gyroscopic stability constraints are some of objectives/constraints taken into *** problem is formulated in All-At-Ones Multidisciplinary Design Optimization approach structure and solved by Simulated Annealing and minimax *** optimal configurations are evaluated in various *** resulted optimal configurations have met all design objectives and constraints.

关键词： Flying projectile optimal design All-at-ones multidisciplinary optimization Structure discipline Guidance and control discipline Aerodynamic discipline

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

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Journal of Mountain Science 2024年第7期21卷 2320-2333页

作者： Ali M.rajabi Ali EDALAT Yasaman ABOLGHASEMI Mahdi KHODAPARAST Department of Engineering Geology University of TehranTehran ***Iran Department of Civil Engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal Aliabad plain Artificial neural network

挤压速度对搅拌摩擦反挤压法制备Cu-5%Ti_(2)SnC复合丝材性能的影响

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Transactions of Nonferrous Metals Society of China 2024年第3期34卷 935-951页

作者： Amirhossein JAHANI Hamed JAMSHIDI AVAL Mohammad rajabi Roohollah JAMAATI Department of Materials Engineering Babol Noshirvani University of TechnologyShariati AvenueBabol 47148-71167Iran

对粉末冶金法制备的含5%(体积分数)Ti_(2)Sn CMAX相的初始复合材料进行搅拌摩擦反挤压(FSBE)处理,研究FSBE工艺的轴向横移速度对Cu-Ti_(2)Sn C复合线材显微组织、力学性能、电学性能和磨损性能的影响。结果表明,随着挤压速度的增加,显... 详细信息

对粉末冶金法制备的含5%(体积分数)Ti_(2)Sn CMAX相的初始复合材料进行搅拌摩擦反挤压(FSBE)处理,研究FSBE工艺的轴向横移速度对Cu-Ti_(2)Sn C复合线材显微组织、力学性能、电学性能和磨损性能的影响。结果表明,随着挤压速度的增加,显微组织中孪晶增多,Ti_(2)SnC颗粒细化,MAX相和Cu基体之间的界面结合改善。当转速为600r/min,轴向横移速度为25mm/min时,Cu-Ti_(2)SnC复合线材具有最大的硬度、屈服强度和极限抗拉强度,分别为HV 132.7、278.34MPa和485.15MPa,这是其更强的界面结合和更细的MAX相导致的。此外,当转速为600 r/min,轴向横移速度为25 mm/min时,Cu-Ti_(2)SnC复合丝的电导率最高,达到89.21%(IACS),磨损率最低,为0.0015 mg/m,这是其更大的晶粒尺寸、更强的界面结合与更低的密度导致的。

关键词：搅拌摩擦反挤压 Ti_(2)SnC MAX相铜基复合材料电导率

A review on the cooling of energy conversion and storage systems using thermoelectric modules

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Journal of Central South University 2024年第6期31卷 1998-2026页

作者： Amirreza IJADI Mehran rajabi ZARGARABADI Saman RASHIDI Amir Mohammad JADIDI Department of Energy Faculty of New Sciences and TechnologiesSemnan UniversitySemnanIran Faculty of Mechanical Engineering Semnan UniversityP.O.B.***SemnanIran

Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic *** load management of these energy conversion and storage systems is one of their challenges and *** this article,the thermal management of these systems using thermoelectric modules is *** results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot *** modules were effective in reducing panel *** increase the time to reach a temperature above 50℃ in batteries by 3 to 4 ***,in their integration with fuel cells,they increase the power density of the fuel cell.

关键词： cooling photovoltaic lithium-ion batteries fuel cell electronic equipment thermoelectric modules

Hepatoprotective effect of Holothuria leucospilota methanolic extract on dimethyl nitrosamine-induced hepatotoxicity in rats

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Animal Models and Experimental Medicine 2024年第4期7卷 544-552页

作者： Fatemeh Dejan Amineh Daneshi Javad rajabi Aslani Nasrollah Ahmadi Narges Eskandari Roozbahani Elaham Rahmanian Reza Behmanesh Hamid Reza Gheisari Department of Basic Sciences School of Veterinary MedicineShiraz UniversityShirazIran Department of Education Farzanegan High SchoolTehranKohgiluyeh and Boyer AhmadIran Food Hygiene Department School of Veterinary MedicineShiraz UniversityShirazIran Department of Pathology School of Veterinary MedicineShiraz UniversityShirazIran Clinical Research Development Center Imam Reza HospitalKermanshah University of Medical SciencesKermanshahIran Molecular Dermatology Research Center Shiraz University of Medical SciencesShirazIran Department of Anatomy School of MedicineShiraz University of Medical SciencesShirazIran Faculty of Veterinary Medicine Garmsar BranchDepartment of RadiologyIslamic Azad UniversityGarmsarIran

Background:Complementary medicine is an interesting field for extracting bio-active compounds from various plant and animal *** hepatoprotective effect of the methanolic extract of a species of sea cucumber called Holothuria leu-cospilota in an animal model of liver cancer caused by dimethyl nitrosamine(DMN)was ***:Wistar female rats were randomly divided into five groups(n=12):control(intact),positive control(received 1%DMN[10 mg/kg/week,intraperitoneally]for 12 weeks),and three treatment groups(received 50,100,and 200 mg/kg/day ***-cospilota extract orally for 12 weeks along with intraperitoneal administration of 1%DMN[10 mg/kg/week]).In all groups,ultrasound was performed on the liver every week to check its *** sampling and liver isolation were performed on three occasions,at 4,8,and 12 weeks,to check liver enzymes and the histopathological condition of the liver tissue(every week,four animals from each group were randomly selected).Results:Liver density changes were evident from the eighth week onward in the positive control *** results indicated pathologic changes in the positive control group after 4 *** increase in liver enzymes in the posi-tive control group was significantly different from that in the treatment and control ***:We demonstrated the hepatoprotective effect of *** on DMN-induced liver damage in rats using biochemical and histological parameters and *** additional research(in silico or in vitro)is needed to find the exact mechanism and the main biological compound in ***.

关键词： dimethyl nitrosamine hepatotoxicity Holothuria leucospilota sea cucumber

Bound States for Hypercentral Singular and Exponential Potentials

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Communications in Theoretical Physics 2006年第4期45卷 669-674页

作者： A.A. rajabi Physics Department Shahrood University of Technology P.O. Box ***-316 Shahrood iran

With a view to obtaining an exact closed form solution to the Schroedinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds of potentials, but in this article it applies to a type of the hypercentral singular potentials V（x） = ax^2 ＋ bx^-4＋ cx^-6 and exponential hypercentral Morse potential U （x） = Uo （ e^-2ax - 2 e^-ax） for three interacting particles. The Morse potential is used for diatomic molecule while this method will be successfully used for many atomic molecules. The three-body potentials are more easily introduced and treated within the hyperspherical harmonic formalism. The internal particle motion is usually described by means of Jacobi relative coordinates p, A, and R, in terms of three particle positions r1, r2, and r3. We discuss some results obtained by using harmonic and anharmonic oscillators, however the hypercentral potential can be easily generalized in order to allow a systematic anaiysis, which admits an exact solution of the wave equation. This method is also applied to some other types of three-body, four-body, ..., interacting potentials.

关键词： hyperspherical harmonic anharmonic three-body Jacobian hypercentral hyperradial

Simulation of proppant transport at intersection of hydraulic fracture and natural fracture of wellbores using CFD-DEM

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Particuology 2022年第4期20卷 112-124页

作者： Siamak Akhshik Majid rajabi Department of Mechanical Engineering Sharif University of TechnologyIran Sustainable Manufacturing Research Laboratory School of Mechanical EngineeringIran University of Science and TechnologyIran

Proppants transport is an advanced technique to improve the hydraulic fracture phenomenon,in order to promote the versatility of gas/oil reservoirs.A numerical simulation of proppants transport at both hydraulic fracture(HF)and natural fracture(NF)intersection is performed to provide a better understand-ing of key factors which cause,or contribute to proppants transport in HF-NF *** fluid dynamics(CFD)in association with discrete element method(DEM)is used to model the complex interactions between proppant particles,host fluid medium and fractured *** effect of non-spherical geometry of particles is considered in this model,using the multi-sphere *** interaction forces between fluid flow and particles are considered in the computational ***,the inter-actions of particle-particle and particle-wall are taken into account via Hertz-Mindlin *** results of the CFD-DEM simulations are compared to the experimental *** is found that the CFD-DEM sim-ulation is capable of predicting proppant transport and deposition quality at intersections which are in agreement with experimental *** results indicate that the HF-NF intersection type,fluid velocity and NF aperture affect the quality of blockage occurrence,presenting a new index,called the blockage coefficient which indicates the severity of the blockage.

关键词： Hydraulic fracture process Proppants transport CFD-DEM method HF-NF intersection Blockage coffcient

A Method to Solve the Schrdinger Equation for Any Power Hypercentral Potentials

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Communications in Theoretical Physics 2007年第7期48卷 151-158页

作者： A.A.rajabi Physics Department Shahrood University of TechnologyP.O.Box ***-316ShahroodIran

An exact closed form of solution to the hyperradial Schrdinger equation is constructed for any generalcase comprising any hypercentral power and inverse-power *** hypercentral potential depends only on thehyperradius,which itself is a function of Jacobi relative coordinates that are functions of particle positions(r_1,r_2,…...,r_N).This article is mainly devoted to the dernonstrat of the fact that any ψ of the form ψ=power series×exp(polynomial)=[f(x)exp(g(x))]is potentially a solution of the Schrdinger equation,where the polynomial g(x)is an ansatz dependingon the interaction potential.

关键词： power hypercenteral potential Shrdinger equation

A NONLINEAR MICROBEAM MODEL BASED ON STRAIN GRADIENT ELASTICITY THEORY

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Acta Mechanica Solida Sinica 2013年第1期26卷 21-34页

作者： Farshid rajabi Shojaa Ramezani Department of Mechanical Engineering Islamic Azad UniversityBandar Anzali BranchAnzaliIran Department of Mechanical Engineering Faculty of EngineeringUniversity of GuilanRashtIran

A micro scale nonlinear beam model based on strain gradient elasticity is developed. Governing equations of motion and boundary conditions are obtained in a variational framework. As an example, the nonlinear vibration of microbeams is analyzed. In a beam having a thickness to length parameter ratio close to unity, the strain gradient effect on increasing the natural frequency is predominant. By increasing the beam thickness, this effect decreases and geometric nonlinearity plays the main role on increasing the natural frequency. For some specific ratios, both geometric nonlinearity and size effects have a significant role on increasing the natural frequency.

关键词： strain gradient elasticity microbeam geometric nonlinearity