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Finite cell method compared to h-version finite element method for elasto-plastic problems

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Applied Mathematics and Mechanics(English Edition) 2014年第10期35卷 1239-1248页

作者： A.ABEDIAN J.PARVIZIAN A.Dster E.RANK Department of Mechanical Engineering Daneshpajoohan Higher Education Institute Department of Mechanical Engineering Isfahan University of Technology Numerische Strukturanalyse mit Anwendungen in der Schiffstechnik (M-10) Technische Universitt Hamburg-Harburg Lehrstuhl fr Computation in Engineering Fakultt fr Bauingenieur-und Vermessungswesen Technische Universitt Mnchen

The finite cell method （FCM） combines the high-order finite element method （FEM） with the fictitious domain approach for the purpose of simple meshing. In the present study, the FCM is used to the Prandtl-Reuss flow theory of plasticity, and the results are compared with the h-version finite element method （h-FEM）. The numerical results show that the FCM is more efficient compared to the h-FEM for elasto-plastic problems, although the mesh does not conform to the boundary. It is also demonstrated that the FCM performs well for elasto-plastic loading and unloading.

关键词： finite cell method (FCM) h-version finite element method (h-FEM),Prandtl-Reuss quadtree octree

Dynamic stress concentration in an infinitely long cylindrical cavity due to a point spherical source embedded within a fluid-saturated poroelastic formation of infinite extent

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 139-156页

作者： h.hOSSEINI O.BALILAShAKI Department of Mechanical Engineering Faculty of EngineeringGolestan University

The effects of a harmonically exciting monopole source on an infinitely long cylindrical cavity embedded entirely within a fluid-saturated poroelastic formation of infinite extent are examined theoretically. It is assumed that the source is located outside the cavity at a specified distance from the borehole axis. The magnitudes of the hoop and radial stresses beside the pore pressures exerted on the interface and inside the porous medium surrounding the borehole are calculated and discussed. Biot's poroelastic modeling along with three types of boundary conditions for the cylindrical interface including the ideal fluid, empty borehole, and rigid inclusion with a hard boundary is employed for the analysis. Utilizing a proper translational addition theorem for expressing the incident spherical wave in terms of cylindrical wave expansions, the proposed boundary conditions at the interface are satisfied. Stresses are formulated by means of wave potential functions in a three-dimensional(3D) manner. The effects of the frequency and the radial distance between the source and borehole on the induced stresses are examined for the first cylindrical modes over frequency spectra. Two permeability conditions for the interface and three types of soils for the porous formation are considered throughout the analysis. To give an overall outline of the study, a numerical example is presented. The results clearly indicate that the distance is a key parameter and has considerable effects on the induced stress values. In addition, the interface permeability condition and soil characteristics play an important role in determining the dynamic response of the borehole. Finally,the obtained results are compared with the relevant analyses existing in the literature for some limit cases, and good agreement is achieved.

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Neuroinflammation as a therapeutic target in huntington's disease

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Neural Regeneration Research 2025年第3期20卷 817-818页

作者： Andrea Kwakowsky Thulani h.Palpagama Center for brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CentreUniversity of GalwayGalwayIreland

In 1872, George huntington presented his essay “On Chorea” to the Meigs and Mason Academy of Medicine and, in doing so, detailed a disease that would later bear his name. huntington's disease(hD) is a genetic, neurodegenerative disease that manifests as the loss of motor control,cognitive impairment,and mood and psychiatric changes in paents.

关键词： huntington inflammation Medicine

Glial response in the midcingulate cortex in huntington’s disease

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Neural Regeneration Research 2025年第1期20卷 207-208页

作者： Thulani h.Palpagama Andrea Kwakowsky Center for brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CenterUniversity of GalwayGalwayIreland

huntington’s disease(hD)is a genetic disease characterized by the progressive degeneration of the striatum and *** can present with a variety of symptoms that can broadly be classified into motor symptoms,inclusive of choreatic movements and rigidity,mood and psychiatric symptoms,such as depression and apathy,and cognitive symptoms,such as cognitive *** causal mutation underlying hD results from an expansion of a CAG repeat sequence on the IT15 gene,resulting in the formation and accumulation of a mutant huntingtin protein.

关键词： huntington degeneration cortex

A creative method to tune Fe–O interaction in ferrites

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Journal of Advanced Ceramics 2023年第8期12卷 1612-1624页

作者： Farshad Farshidfar Arash Fattahi Ralf brüning Dominic h.Ryan Khashayar Ghandi Department of Chemistry University of GuelphGuelph N1G 2W1Canada Physics Department Mount Allison UniversitySackville E4L 1E6Canada Physics Department McGill UniversityMontreal H3A 2T8Canada

To be able to regulate the anionic oxygen position in ferrites,an original compositing method is developed by introducing a porous p-type phase in the n-type matrix of ferrite spinel semiconductors.A result of this method is the synergetic effect of the enhanced mass and charge transport that impacted the morphology and anionic oxygen position within the MgFe_(2)O_(4) *** hypothesis is that fine tuning of the anionic oxygen position in ferrites allows us to regulate their physicochemical properties significantly,with the implications for diverse *** electron exchange interaction(J)between O-centered and octahedral-occupying iron(Fe)-centered orbitals affected both the electrical and magnetic properties of the matrix significantly,supporting our *** three-dimensional variable range electron hopping is one such effect.

关键词： Fe_(2)O_(4) spinel structural distortion electron hopping

Does mesenchymal stem cell’s secretome affect spinal sensory circuits?Implication for pain therapies

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Neural Regeneration Research 2025年第1期20卷 181-183页

作者： Francesco Ferrini Esri h.Juárez Adalberto Merighi Department of Veterinary Sciences University of TurinGrugliascoTOItaly Department of Psychiatry and Neuroscience UniversitéLavalQuébec CityQCCanada

Mesenchymal stem cells(MSCs)are multipotent adult stem cells of mesodermal origin that can be isolated from various tissues,including bone marrow,tooth pulp,adipose tissue,and umbilical *** have gained significant attention in regenerative medicine due to their ability to modulate the immune system and favor tissue *** enrich the medium in which they are cultivated with a broad range of bioactive molecules,including growth factors,cytokines,chemokines,enzymes,nucleic acids,and extracellular vesicles that collectively compose the MSC *** increasing number of pre-clinical studies suggest that delivering in vivo an MSC-conditioned medium(i.e.,the medium collected from MSC cultures after at least 3 days of exposure)exerts neuroprotective and anti-inflammatory effects in a variety of neurological conditions.

关键词： protective clinical collective

Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura h.AL-REKABI A.A.ALWAhIB Electrical Technique Department Al Suwayrah Technical Institute Middle Technical University Laser and Optoelectronics Department University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium（Cr） has been investigated. One of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human, animals and plants are hexavalent Cr（Ⅵ）. Consequently, highly sensitive sensor to detect Cr is essential. Surface plasmon resonance（SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study, three types of prism-based SPR sensor, gold（Au）/silver（Ag）, Au/polyaniline（PANI） and Au/titanium dioxide（TiO2） nanostructured films, are investigated as potential sensing material to detect the presence of Cr（Ⅵ） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag, Au/PANI nanofibers and Au/TiO2sensor films, the Cr（Ⅵ） concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm-1, 0.082 °ppm-1and 0.039 °ppm-1, respectively. Based on these results, the Au/PANI nanofibers are the most sensitive to Cr（Ⅵ） among the tested sensing materials.

关键词： Titanium dioxide

A chip-scale second-harmonic source via self-injection-locked all-optical poling

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Light(Science & Applications) 2023年第12期12卷 2778-2787页

作者： Marco Clementi Edgars Nitiss Junqiu Liu Elena Durán-Valdeiglesias Sofiane Belahsene hélène Debrégeas Tobias JKippenberg Camille-Sophie brès Photonic Systems Laboratory(PhOSL) École Polytechnique Fédérale de Lausanne1015 LausanneSwitzerland Laboratory of Photonics and Quantum Measurements(LPQM) École Polytechnique Fédérale de Lausanne1015 LausanneSwitzerland Almae Technologies Route de Nozay91460 MarcoussisFrance

Second-harmonic generation allows for coherently bridging distant regions of the optical spectrum,with applications ranging from laser technology to self-referencing of frequency ***,accessing the nonlinear response of a medium typically requires high-power bulk sources,specific nonlinear crystals,and complex optical setups,hindering the path toward large-scale *** we address all of these issues by engineering a chip-scale second-harmonic(Sh)source based on the frequency doubling of a semiconductor laser self-injection-locked to a silicon nitride *** injection-locking mechanism,combined with a high-Q microresonator,results in an ultra-narrow intrinsic linewidth at the fundamental harmonic frequency as small as 41 *** to the extreme resonant field enhancement,quasi-phase-matched second-order nonlinearity is photoinduced through the coherent photogalvanic effect and the high coherence is mapped on the generated Sh *** show how such optical poling technique can be engineered to provide efficient Sh generation across the whole C and L telecom bands,in a reconfigurable fashion,overcoming the need for poling *** device operates with milliwatt-level pumping and outputs Sh power exceeding 2 mW,for an efficiency as high as 280%/W under electrical *** findings suggest that standalone,highly-coherent,and efficient Sh sources can be integrated in current silicon nitride photonics,unlocking the potential of x(2)processes in the next generation of integrated photonic devices.

关键词： resonator harmonic injection

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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