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Size-dependent effect on biaxial and shear nonlinear buckling analysis of nonlocal isotropic and orthotropic micro-plate based on surface stress and modified couple stress theories using differential quadrature method

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Applied mathematics and mechanics(English Edition) 2016年第4期37卷 529-554页

作者： m.mohammadimehr m.A.mohammadimehr P.DASHTI Department of Solid mechanics Faculty of Mechanical EngineeringUniversity of Kashan

The size-dependent effect on the biaxial and shear nonlinear buckling analysis of an isotropic and orthotropic micro-plate based on the surface stress, the modified couple stress theory （mCST）, and the nonlocal elasticity theories using the differential quadrature method （DQm） is presented. main advantages of the mCST over the classical theory （CT） are the inclusion of the asymmetric couple stress tensor and the consideration of only one material length scale parameter. Based on the nonlinear von Karman assumption, the governing equations of equilibrium for the micro-classical plate consid- ering midplane displacements are derived based on the minimum principle of potential energy. Using the DQm, the biaxial and shear critical buckling loads of the micro-plate for various boundary conditions are obtained. Accuracy of the obtained results is validated by comparing the solutions with those reported in the literature. A parametric study is conducted to show the effects of the aspect ratio, the side-to-thickness ratio, Eringen＇s nonlocal parameter, the material length scale parameter, Young＇s modulus of the surface layer, the surface residual stress, the polymer matrix coefficients, and various boundary conditions on the dimensionless uniaxial, biaxial, and shear critical buckling loads. The results indicate that the critical buckling loads are strongly sensitive to Eringen＇s nonlocal parameter, the material length scale parameter, and the surface residual stress effects, while the effect of Young＇s modulus of the surface layer on the critical buckling load is negligible. Also, considering the size dependent effect causes the increase in the stiffness of the orthotropic micro-plate. The results show that the critical biaxial buckling load increases with an increase in G12/E2 and vice versa for E1/E2. It is shown that the nonlinear biaxial buckling ratio decreases as the aspect ratio increases and vice versa for the buckling amplitude. Because of the most lightweight mic

关键词： biaxial and shear nonlinear buckling analysis nonlocal isotropic and orthotropic micro-plate modified couple stress theory (mCST) surface stress effect differential quadrature method (DQm)

Bending and vibration analyses of a rotating sandwich cylindrical shell considering nanocomposite core and piezoelectric layers subjected to thermal and magnetic fields

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Applied mathematics and mechanics(English Edition) 2018年第2期39卷 219-240页

作者： m.mohammadimehr R.ROSTAmI Department of Solid mechanics Faculty of Mechanical Engineering University of Kashan

The bending and free vibration of a rotating sandwich cylindrical shell are analyzed with the consideration of the nanocomposite core and piezoelectric layers subjected to thermal and magnetic fields by use of the first-order shear deformation theory （FSDT） of shells. The governing equations of motion and the corresponding boundary conditions are established through the variational method and the maxwell equation. The closed-form solutions of the rotating sandwich cylindrical shell are obtained. The effects of geometrical parameters, volume fractions of carbon nanotubes, applied voltages on the inner and outer piezoelectric layers, and magnetic and thermal fields on the natural frequency, critical angular velocity, and deflection of the sandwich cylindrical shell are investigated. The critical angular velocity of the nanocomposite sandwich cylindrical shell is obtained. The results show that the mechanical properties, e.g., Young＇s modulus and thermal expansion coefficient, for the carbon nanotube and matrix are functions of temperature, and the magnitude of the critical angular velocity can be adjusted by changing the applied voltage.

关键词： free vibration bending rotating sandwich cylindrical shell nanocompositecore piezoelectric layer

Stress and buckling analysis of a thick-walled micro sandwich panel with a flexible foam core and carbon nanotube reinforced composite (CNTRC) face sheets

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Applied mathematics and mechanics(English Edition) 2020年第7期41卷 1027-1038页

作者： A.AmIRI m.mohammadimehr m.ANVARI Department of Solid mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan 87317Iran

In this paper,the stresses and buckling behaviors of a thick-walled mi-cro sandwich panel with a flexible foam core and carbon nanotube reinforced composite(CNTRC)face sheets are considered based on the high-order shear deformation theory(HSDT)and the modified couple stress theory(mCST).The governing equations of equi-librium are obtained based on the total potential energy *** effects of various parameters such as the aspect ratio,elastic foundation,temperature changes,and volume fraction of the canbon nanotubes(CNTs)on the critical buckling loads,normal stress,shear stress,and deflection of the thick-walled micro cylindrical sandwich panel consider-ing different distributions of CNTs are *** results are compared and validated with other studies,and showing an excellent *** have become very use-ful and common candidates in sandwich structures,and they have been extensively used in many applications including nanotechnology,aerospace,and *** paper also extends further applications of reinforced sandwich panels by providing the modified equations and formulae.

关键词： stress and buckling analysis thick-walled micro cylindrical sandwich panel flexible foam core carbon nanotube reinforced composite(CNTRC)face sheet high-order shear deformation theory(HSDT)

Control and vibration analyses of a sandwich doubly curved micro-composite shell with honeycomb,truss,and corrugated cores based on the fourth-order shear deformation theory

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Applied mathematics and mechanics(English Edition) 2024年第10期45卷 1773-1790页

作者： F.SHIRDELAN m.mohammadimehr F.BARGOZINI Department of Solid mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan 87317-53153Iran

Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive ***,the inability of controlling and regulating vibrations and destroying them afterward is a challenge to *** this paper,the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms.A five-layer sandwich doubly curved micro-composite shell,comprising two piezoelectric layers for the sensor and actuator,is modeled by the fourth-order shear deformation *** core(honeycomb,truss,and corrugated)is analyzed for the bearing of transverse shear *** results show that the honeycomb core has a greater effect on the *** the parameters related to the core and the weight percentage of graphene increase,the frequency *** uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency ***,without taking into account the piezoelectric layers,the third-order shear deformation theory(TSDT)and fourth-order shear deformation theory(FOSDT)align ***,when the piezoelectric layers are incorporated,these two theories diverge significantly,with the frequencies in the FOSDT being lower than those in the TSDT.

关键词： vibration and control doubly curved shell micro-composite honeycomb truss corrugate core

Vibration and wave propagation analysis of twisted micro-beam using strain gradient theory

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Applied mathematics and mechanics(English Edition) 2016年第10期37卷 1375-1392页

作者： m.mohammadimehr m.J.FARAHI S.ALImIRZAEI Department of Solid mechanics Faculty of Mechanical Engineering University of Kashan

In this research, vibration and wave propagation analysis of a twisted micro- beam on Pasternak foundation is investigated. The strain-displacement relations （kine-matic equations） are calculated by the displacement fields of the twisted micro-beam. The strain gradient theory （SGT） is used to implement the size dependent effect at micro-scale. Finally, using an energy method and Hamilton＇s principle, the governing equations of motion for the twisted micro-beam are derived. Natural frequencies and the wave prop- agation speed of the twisted micro-beam are calculated with an analytical method. Also, the natural frequency, the phase speed, the cut-off frequency, and the wave number of the twisted micro-beam are obtained by considering three material length scale parameters, the rate of twist angle, the thickness, the length of twisted micro-beam, and the elastic medium. The results of this work indicate that the phase speed in a twisted micro-beam increases with an increase in the rate of twist angle. moreover, the wave number is in- versely related with the thickness of micro-beam. meanwhile, it is directly related to the wave propagation frequency. Increasing the rate of twist angle causes the increase in the natural frequency especially with higher thickness. The effect of the twist angle rate on the group velocity is observed at a lower wave propagation frequency.

关键词： vibration and wave propagation analysis twisted micro-beam strain gradient theory (SGT) rate of twist angle

Bending,buckling and vibration analyses of mSGT microcomposite circular-annular sandwich plate under hydro-thermo-magneto-mechanical loadings using DQm

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International Journal of Smart and Nano materials 2018年第4期9卷 233-260,I0002页

作者： m.mohammadimehr m.Emdadi H.Afshari B.Rousta Navi Department of Solid mechanics Faculty of Mechanical EngineeringUniversity of KashanKashanIran

The purpose of this paper is to investigate the bending,buckling,vibration analyses of microcomposite circular-annular sandwich plate with CNT reinforced composite facesheets under hydro-thermo-magneto-mechanical loadings are presented using first order shear deformation theory(FSDT)and modified strain gradient theory(mSGT)that includes three material length scale ***,an isotropic homogeneous core is considered for microcomposite circular-annular sandwich *** generalized rule of mixture is employed to predict mechanical,moisture and thermal properties ofmicrocomposite sandwich *** using Hamilton’s principle,governing equations are solved by differential quadrature method(DQm)for a circular annular sandwich *** predicted results are validated by carrying out the comparison studies for the FGm plates by modified couple stress theory(mCST).The obtained results are given to indicate the influence of the material length scale parameter,core-to-facesheet thickness ratios,magnetic effect,thermal andmoisture effects on the dimensionless deflection,critical buckling load,and natural frequency of microcomposite circular sandwich *** results can be employed in solid-state physics,materials science,nano-electronics,and nano electro-mechanical devices such as microactuators,and microsensor.

关键词： Bending buckling free vibration analyses circular annular sandwich plate CNT reinforced composite facesheets first order shear deformation and modified strain gradient theories

Forced vibration analysis of nano-composite rotating pressurized microbeam reinforced by CNTs based on mCST with temperature-variable material properties

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Theoretical & Applied mechanics Letters 2018年第2期8卷 97-108页

作者： R.Rostami m.mohammadimehr m.Ghannad A.Jalali Department of Solid mechanics Faculty of Mechanical EngineeringShahrood University of Technology Department of Solid mechanics Faculty of Mechanical EngineeringUniversity of Kashan

In this study, free and forced vibration analysis of nano-composite rotating pressurized microbeam reinforced by carbon nanotubes （CNTs） under magnetic field based on modify couple stress theory （mCST） with temperature-variable material propertiesis presented. Also, the boundary conditions at two ends of nano-composite rotating pressurized microbeam reinforced by CNTs are considered as simply supported. The governing equations are obtained based on the Hamilton＇s principle and then computed these equations by using Navier＇s solution. The magnetic field is inserted in the thickness direction of the nano-composite microbeam. The effects of various parameters such as angular velocity, temperature changes, and pressure between of the inside and outside, the magnetic field, material length scale parameter, and volume fraction of nanocomposite microbeam on the natural frequency and response systemare studied. The results show that with increasing volume fraction of nano-composite microbeam, thickness, material length scale parameter, and magnetic fields, the natural frequency increases. The results of this research can be used for optimization of micro-structures and manufacturing sensors, displacement fluid, and drug delivery.

关键词： Forced vibration analysis Nano-composite rotating pressurized microbeam Carbon nanotubes modify couple stress theory Temperature-variable material properties

Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa Department of Psychology and Neuroscience Duke UniversityDurhamNCUSA Department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

SBL-JP-0004:A promising dual inhibitor of JAK2 and PI3KCD against gastric cancer

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Oncology Research 2025年第1期33卷 235-243页

作者： HASSAN m.OTIFI Department of Pathology College of MedicineKing Khalid UniversityAbha62521Saudi Arabia

Background:Gastric cancer(GC)remains a global health burden and is often characterized by heterogeneous molecular profiles and resistance to conventional *** phosphoinositide 3-kinase and PI3K and Janus kinase(JAK)signal transducer and activator of transcription(JAK-STAT)pathways play pivotal roles in GC progression,making them attractive targets for therapeutic ***:This study applied a computational and molecular dynamics simulation approach to identify and characterize SBL-JP-0004 as a potential dual inhibitor of JAK2 and PI3KCD *** and SNU-5 GC cells were used for in vitro ***:SBL-JP-0004 exhibited a robust binding affinity for JAK2 and PI3KCD kinases,as evidenced by molecular docking scores and molecular dynamics *** interactions and Gibbs binding free energy estimates confirmed stable and favorable interactions with target ***-JP-0004 displayed an half-maximal inhibitory concentration(IC_(50))value of 118.9 nm against JAK2 kinase and 200.9 nm against PI3KCD ***-JP-0004 exhibited potent inhibition of cell proliferation in KATOIII and SNU-5 cells,with half-maximal growth inhibitory concentration(GI50)values of 250.8 and 516.3 nm,respectively.A significant elevation in the early phase apoptosis(28.53%in KATOIII cells and 26.85%in SNU-5 cells)and late phase apoptosis(17.37%in KATOIII cells and 10.05%in SNU-5 cells)were observed with SBL-JP-0004 treatment compared to 2.1%and 2.83%in their respective ***:The results highlight SBL-JP-0004 as a promising dual inhibitor targeting JAK2 and PI3KCD kinases for treating GC and warrant further preclinical and clinical investigations to validate its utility in clinical settings.

关键词： Gastric cancer(GC) Dual inhibition JAK2 PI3KCD SBL-JP-0004 molecular docking molecular dynamics simulation