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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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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

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

Effects of Welding and rotational speeds on the Microstructure and hardness of Friction stir Welded single-Phase Brass

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Acta Metallurgica sinica(English Letters) 2015年第6期28卷 766-771页

作者： sajjad Emami Tohid saeid Materials Engineering Faculty Sahand University of Technology

This study focuses on the effects of rotational and welding speeds on the microstructure and hardness of joints in friction stir welded single-phase brass. Welds were achieved under low heat input conditions at rotational and welding speeds of 400-800 r/min and 100-300 mm/min, respectively. In order to characterize the obtained welds, optical microscopy and Vickers hardness measurements were taken on the weld cross sections. According to the obtained results, increasing the welding speed and/or decreasing the rotational speed caused the grain size of the stir zone to decrease and, hence, improved the average hardness of this region. These results are discussed with respect to the interplay between the welding parameters and the peak temperature in the weld thermal cycle.

关键词： Friction stir welding single-phase brass Dynamic recrystailization hardness

strong interfacial charge transfer between hausmannite manganese oxide and alumina for efficient photocatalysis

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Chinese Journal of Chemical Engineering 2021年第5期34卷 147-159页

作者： Aisha Kanwal shamaila sajjad sajjad Ahmed Khan Leghari Muhammad Naeem Khan International Islamic University H-10 IslamabadPakistan Pakistan Institute of Engineering and Applied sciences Islamabad 44000Pakistan Department of Chemistry Government College of ScienceLahorePakistan

Well crystalline manganese oxide(Mn_(3)O_(4))nanoparticles anchored on gamma alumina(γ-Al_(2)O_(3))have been successfully tailored via a proficient and cost effective chemical process as an efficient material for photo *** indicated the composite formation ofγ-Al_(2)O_(3) and hausmannite structure of Mn_(3)O_(4).sEM and TEM revealed that hetero structure of Mn_(3)O_(4)/γ-Al_(2)O_(3) exhibits an amalgam of aggregated nanoparticles and *** demonstrated the chemical states of binary *** band gap tuning has been performed withγ-Al_(2)O_(3) nanoparticles by assimilating hausmannite Mn_(3)O_(4) particles into flower like microstructure of Al_(2)O_(3).The photoluminescence spectra affirmed the enhancement in charge separation in Mn_(3)O_(4)/γ-Al_(2)O_(3) binary hybrid *** band gap becomes narrow with the increase in concentrations of Mn_(3)O_(4).The narrowing of band gap is concorded with crystalline domains of primary aggregated *** elucidate the mechanism of the photocatalytic activity linear sweep voltammetry was *** results showed that Mn_(3)O_(4)/γ-Al_(2)O_(3) nanocomposite revealed the enhancement in current density as compared to pureγ-Al_(2)O_(3) which confirmed the electron transfer from Mn_(3)O_(4) toγ-Al_(2)O_(3) through the interfacial potential gradient in conduction *** optimum concentration of 6.0%Mn_(3)O_(4)/γ-Al_(2)O_(3) for hybrid structure showed an excellent photocatalytic activity under visible light due to narrow band gap *** degree distribution of Mn_(3)O_(4) nano architects overlying onγ-Al_(2)O_(3) induces a significant synergic effect betweenγ-Al_(2)O_(3) and hausmannite phase of manganese oxide(Mn_(3)O_(4)).This strong interfacial contact betweenγ-Al_(2)O_(3) and Mn_(3)O_(4) endures the quick transfer of photo generated charge carriers across interface.

关键词： hausmannite Mn_(3)O_(4) Alumina Band gap tuning Interfacial charge transfer Nanomaterials Catalysis

Effects of the deep rolling process on the surface roughness and properties of an Al-3vol%siC nanoparticle nanocomposite fabricated by mechanical milling and hot extrusion

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 814-825页

作者： sajjad sattari Amir Atrian Department of Mechanical Engineering Najafabad Branch Islamic Azad University Najafabad Iran Modem Manufacturing Technologies Research Center Najafabad Branch Islamic Azad University Najafabad lran

Deep rolling is one of the most widely used surface mechanical treatments among several methods used to generate compressive residual stress. This process is usually used for axisymmetric components and can lead to improvements of the surface quality, dimensional accuracy, and mechanical properties. In this study, we deduced the appropriate deep rolling parameters for Al-3vol%si C nanocomposite samples using roughness and microhardness measurements. The nanocomposite samples were fabricated using a combination of mechanical milling, cold pressing, and hot extrusion techniques. Density measurements indicated acceptable densification of the samples, with no porosity. The results of tensile tests showed that the samples are sufficiently strong for the deep rolling process and also indicated near 50% improvement of tensile strength after incorporating si C nanoparticle reinforcements. The effects of some important rolling parameters, including the penetration depth, rotation speed, feed rate, and the number of passes, on the surface quality and microhardness were also investigated. The results demonstrated that decreasing the feed rate and increasing the number of passes can lead to greater surface hardness and lower surface roughness.

关键词： deep rolling nanocomposite mechanical milling hot extrusion roughness hardness

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

Electron heat Diffusivity Measurement by Perturbative Method on hT-7 Tokamak

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Plasma science and Technology 2008年第6期10卷 681-684页

作者：杜勤凌必利提昂高翔费勤山 s.sajjad 熊川 Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

spatio-temporal evolutions of the sawteeth activities are measured simultaneously with a 16 channel high spatio-temporal resolution electron cyclotron emission （ECE） heterodyne radiometer on hT-7 and the evolutions of the sawteeth are found to be diffusive in character. By a perturbative analysis, the electron heat diffusivity Хe inferred by time-to-peak method and Fourier transform shows a good agreement. The value of electron heat diffusivity shows radial asymmetry between the low magnetic field side （LFs） and the high magnetic field side （hFs）. It is observed that with the increase in plasma density, the electron heat diffusivity decreases and the confinement of energy is improved. By comparing with Хe^pb inferred by static power balance analysis, the result indicate that Хe^hp is larger than Хe^pb by a factor ranging from 2 to 10.

关键词： ECE electron thermal diffusivity time-to-peak Fourier transform