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friction coefficient and microhardness of anodized aluminum alloys under different elaboration conditions

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Transactions of Nonferrous Metals Society of China 2015年第6期25卷 1950-1960页

作者： M.GUEZMIL W.BENSALAh A.KhALLADI K.ELLEUCh M.DEPETRIS-WERY h.f.ayedi Laboratoire de Génie des Matériaux et Environnement (LGME) IUT Mesures Physiques d’Orsay-University of Paris-Sud 11

The effects of anodizing conditions （electrolyte, current density and temperature） on the friction coefficient and Vickers mierohardness of anodic oxide layers formed on A1 5754 and A1 1050A substrates were investigated. The studied properties were examined using DELTALAB hVS-1000 Vickers mierohardness tester and rotating pin on disc tribometer. It was established that the highest microhardness （〉hV 400） and the lowest friction coefficient （〈0.4） were obtained with the oxalic acid addition of 10 g/L at high current density of 3 A/dm2 and low temperature of 5 ~C. The presence of oxidized Mg through the anodic oxide layer formed on A1 5754 was examined using glow-discharge optical emission spectroscopy （GDOES）. The MgO was found to act negatively on the mechanical property of the layer. finally, the scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS）, and atomic force microscopy （AfM） were used to characterize the anodic layer before and after friction tests. It is found that the wear mechanism is related to many aspects of the initial morphology, chemical composition of the layer （C, S and Mg）, porosity and internal stress.

关键词： aluminium alloy anodization friction coefficient microhardness dry sliding friction surface characterization

Thick and Dense Anodic Oxide Layers formed on Aluminum in Sulphuric Acid Bath

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Journal of Materials Science & Technology 2010年第2期26卷 113-118页

作者： W. Bensalah M. feki M. Wery h.f. ayedi URCIM Department of Materials EngineeringNational School of Engineering IUT Orsay-Paris XI University Plateau du Moulon URCIM Department of Materials Engineering National School of Engineering

Thick and dense oxide layers were obtained on aluminium in sulphuric acid electrolyte. for this purpose, the methodology of experimental design was used. A three-variables Doehlert design （bath temperature, anodic current density, sulphuric acid concentration）, was achieved. In order to maximize the growth rate and the density of the anodic oxide layer, optimum path study was conducted. Under the determined optimal anodizing conditions （5.7℃, 3 ***-2,Csul=140 g.L-1）, the estimated response values were 0.86 μmin-1 and 3.12 ***-2 for growth rate and density, respectively. The morphology of optimum layer was examined by scanning electron microscopy （SEM）. The compactness of the optimum anodic layer can be correlated with its morphology revealed by SEM observations.

关键词： Sulphuric anodization Experimental design Growth rate Density

hybrid Chaotic Salp Swarm with Crossover Algorithm for Underground Wireless Sensor Networks

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Computers, Materials & Continua 2022年第8期72卷 2963-2980页

作者： Mariem ayedi Walaa h.ElAshmawi Esraa Eldesouky first Department of Computer Science College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia MEDIATRON Lab. SUP’COMCarthage UniversityTunis2083Tunisia Department of Computer Science Faculty of Computers and InformaticsSuez Canal UniversityIsmailia41522Egypt faculty of Computer Science Misr International UniversityCairoEgypt

Resource management in Underground Wireless Sensor Networks(UWSNs)is one of the pillars to extend the network *** intriguing design goal for such networks is to achieve balanced energy and spectral resource *** paper focuses on optimizing the resource efficiency in UWSNs where underground relay nodes amplify and forward sensed data,received from the buried source nodes through a lossy soil medium,to the aboveground base station.A new algorithm called the hybrid Chaotic Salp Swarm and Crossover(hCSSC)algorithm is proposed to obtain the optimal source and relay transmission powers to maximize the network resource *** proposed algorithm improves the standard Salp Swarm Algorithm(SSA)by considering a chaotic map to initialize the population along with performing the crossover technique in the position updates of *** experimental results,the hCSSC algorithm proves its outstanding superiority to the standard SSA for resource efficiency ***,the network’s lifetime is ***,the proposed algorithm achieves an improvement performance of 23.6%and 20.4%for the resource efficiency and average remaining relay battery per transmission,***,simulation results demonstrate that the hCSSC algorithm proves its efficacy in the case of both equal and different node battery capacities.

关键词： Underground wireless sensor networks resource efficiency chaotic theory crossover algorithm salp swarm algorithm

Mechanical and Abrasive Wear Properties of Anodic Oxide Layers formed on Aluminium

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Journal of Materials Science & Technology 2009年第4期25卷 508-512页

作者： W. Bensalah K. Elleuch M. feki M. Wery h.f. ayedi Unit'e de Recherche de Chimie Industrielle et Mat'eriaux(URCIM) Departement of Materials EngineeringNational School of Engineering IUT Orsay-Paris XI University

Aluminium oxide coatings were formed on aluminium substrates in oxalic acid-sulphuric acid bath. Abrasion tests of the obtained anodic layers were carried out on a pin-on-disc machine in accordance with the ISO/DP 825 specifications. The rickets microhardness, D （hV0.2）, and the abrasion weight loss, Wa （mg） were measured. Influence of oxalic acid concentration （Cox）, bath temperature （T） and anodic current density （J） on D and Wa has been examined, and the sulphuric acid concentration （Csul） was maintained at 100 g.L-1. It was found that high microhardness and abrasive wear resistance of oxide layers were produced under low temperatures and high current densities with the addition of oxalic acid. The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy （SEM）, atomic force microscopy （AfM）, optical microscopy and glow-discharge optical emission spectroscopy （GDOES）. It was found that the chemistry of the anodizing electrolyte, temperature, and current density are the controlling factors of the mechanical properties of the anodic oxide layer.

关键词： Aluminium oxide Vickers microhardness Abrasive wear

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

Leveraging ROTI map derived from Indonesian GNSS receiver network for advancing study of Equatorial Plasma Bubble in Southeast/East Asia

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Earth and Planetary Physics 2025年第1期9卷 101-116页

作者： Prayitno Abadi Ihsan N.Muafiry Teguh N.Pratama Angga Y.Putra Suraina Gatot h.Pramono Sidik T.Wibowo febrylian f.Chabibi Umar A.Ahmad Wildan P.Tresna Asnawi Research Center for Climate and Atmosphere Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia School of Electrical Engineering Telkom UniversityBandungIndonesia Directorate of Laboratory Management facilities and Science and Technology Park Indonesian National Research and Innovation Agency(BRIN)PontianakIndonesia Geophysics Laboratory Master Program in PhysicsUniversitas Gadjah Mada(UGM)YogyakartaIndonesia Research Center for Space Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia Indonesian Geospatial Information Agency(BIG) JakartaIndonesia Research Center for Photonics Indonesian National Research and Innovation Agency(BRIN)Tangerang SelatanIndonesia Department of Earth and Planetary Sciences Hokkaido UniversitySapporoJapan

This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning *** by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude ***-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast *** provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this *** generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific *** preliminary findings from the ROTI maps of Ina-CORS are ***,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther ***,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East *** have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,*** observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities *** sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionosphe

关键词： Equatorial Plasma Bubble(EPB) GNSS receivers’network Indonesia Continuously Operating Reference Station(Ina-CORS) ionospheric map Rate of TEC change index(ROTI)map

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