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Applied mathematics and mechanics(English Edition) 2024年第2期45卷 373-388页

作者： m.RAHmAN m.TURKYILmAzOGLU z.mUSHTAQ Department of mathematics Mirpur University of Science and TechnologyMirpur 10250Pakistan Department of mathematics Hacettepe UniversityBeytepeAnkara 06532Turkiye

In this study,we examine the effects of various shapes of nanoparticles in a steady flow of hybrid nanofluids between two stretchable rotating *** steady flow of hybrid nanofluids with transformer oil as the base fluid and Fe_(3)O_(4)+TiO_(2)as the hybrid nanofluid is *** shapes of Fe_(3)O_(4)+TiO_(2)hybrid nanofluids,including sphere,brick,blade,cylinder,and platelet,are *** shape exists in the same volume of a *** leading equations(partial differential equations(PDEs))are transformed to the nonlinear ordinary differential equations(ODEs)with the help of similarity *** system of equations takes the form of ODEs depending on the boundary conditions,whose solutions are computed numerically by the bvp4c mATLAB *** outputs are compared with the previous findings,and an intriguing pattern is discovered,such that the tangential velocity is increased for the rotation parameter,while it is decreased by the stretching values because of the lower *** the reaction rate parameter,the concentration boundary layer becomes shorter,and the activation energy component increases the rate at which mass transfers come to the higher disk but have the opposite effect on the bottom *** ranges of various parameters taken into account are pr=6.2,Re=2,m=1.0,φ_(1)=φ_(2)=0.03,K=0.5,S=-0.1,Br=0.3,Sc=2.0,α_(1)=0.2,γ=0.1,E_(n)=2.0,and q=1.0,and the rotation factor K is within the range of 0 to 1.

关键词： transformer oil Brinkman number skin friction coefficient double rotating disk Nusselt number Sherwood number

Compressive property and energy absorption characteristic of interconnected porous mg-zn-Y alloys with adjusting Y addition

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Journal of magnesium and Alloys 2024年第1期12卷 171-185页

作者： J.A.Liu S.J.Liu B.Wang W.B.Sun X.J.Liu z.W.Han College of materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-Jilin University Weihai 264205PR China

In this study,interconnected porous mg-2zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption *** characterization methods were then applied to identify the microstructure of the porous mg-zn-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different mg-zn-Y ternary phases appear:I-phase(mg_(3)zn_(6)Y),W-phase(mg_(3)zn_(3)Y_(2)),and LPSO phase(mg_(12)znY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30mPa to 9.23 mPa,and the energy absorption capacity increases from 7.33 mJ/m^(3)to 10.97 mJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous mg-zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous mg-zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements microstructure Compressive behavior Energy absorption characteristic

Assessment of bisphenols in children's toy and baby products in the middle East

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Emerging Contaminants 2024年第3期10卷 336-342页

作者： K.martínez-Guijarro B.Gevao m.Porcelli S.Al-Salem Saif Uddin m.Bahloul H.Taqi m.Hajeyah D.Krishnan S.Rajagopalan A.Boota Environment Pollution and Climate program Kuwait Institute for Scientific ResearchP.O.Box 23884SafatKuwait EPA Sierra Leone

A major concern from the scientific community has been raised since evidence of Bisphenol A(BP-A)can leach out from the products where they are incorporated as well as its endocrine disrupting effects observed in animals and ***-A and several related chemicals such as Bisphenol AP(BP-AP),Bisphenol B(BPeB),Bisphenol S(BPeS),Bisphenol AF(BP-AF),Bisphenol(BPeP),Bisphenol z(BP-z)were analyzed in this ***-A and BP-S were the only bisphenols detected in the samples analyzed in this *** median(range;mean)concentrations of BP-A found in this study was 321 ng/g(11-200932;4893 ng/g).The analysis was carried out by sonicating 0.1 g of a cryo-milled sample aliquot in methanol followed by UPLC-mS/mS *** concentrations of BP-A were found in several products labeled as BP-A free such as nursing bottles which are particularly problematic from the children's exposure point of *** study presents the first reliable bisphenols in children's toys and baby products commercialized in the middle *** is,however,a need to continue monitoring these compounds,especially in low-cost toys,and the so-called BP-A-free products,which appear to have high levels of target contaminants and can pose an exposure risk for infants and children in the region.

关键词： Bisphenols Bisphenol A(BP-A) Bisphenol S(BPeS) Children Toys

Solidification, microstructure, and mechanical properties of the as-cast zRE1 magnesium alloy with different praseodymium contents

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International Journal of minerals,metallurgy and materials 2017年第11期24卷 1306-1320页

作者： z.m.Sheggaf R.Ahmad m.B.A.Asmael A.m.m.Elaswad Department of manufacturing and Industrial Engineering Faculty of Mechanical and Manufacturing Engineering Universiti Tun Hussein Onn Malaysia Parit Raja86400 BatuPahat Johor Malaysia Department of mechanical Engineering Eastern Mediterranean University North Cyprus Gazimagsa TRNC Mersin 10 Turkey

The influence of praseodymium(pr) content on the solidification characteristics, microstructure, and mechanical properties of zRE1 magnesium(mg) cast alloy was investigated. The obtained solidification parameters showed that pr strongly affected the solidification time, leading to refinement of the microstructure of the alloys. When the freezing time was reduced to approximately 52 s, the grain size decreased by 12%. mg_(12)zn(Ce,pr) was formed as a new phase upon the addition of pr and was detected via X-ray diffraction analysis. The addition of pr led to a substantial improvement in mechanical properties, which was attributed to the formation of intermetallic compounds; the ultimate tensile strength and yield strength increased by approximately 10% and 13%, respectively. pr addition also refined the microstructure, and the hardness was recovered. The results herein demonstrate that the mechanical properties of mg alloys are strongly influenced by their microstructure characteristics, including the grain size, volume fraction, and distribution of intermetallic phases.

关键词： metal solidification microstructure mechanical properties magnesium alloys intermetallics

Numerical Simulation of Separated Flows in Channels

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Journal of Thermal Science 2012年第2期21卷 145-153页

作者： Petr Louda Jaromír príhoda Petr Sváek Karel Kozel Czech Technical University in prague Fac. of Mechanical Engineering Karlovo nám. 13 CZ-121 35 Praha 2 Institute of Thermomechanics AS CR v.v.i. Dolejkova 5 CZ-182 00 Praha 8

The work deals with numerical modelling of turbulent flows in channels with an expansion of the cross-section where flow separation and reattachment occur. The performance of several eddy viscosity models and an explicit algebraic Reynolds stress model (EARSm) is studied. The used test cases are flows in channels with various backward facing steps where the step is perpendicular or inclined and the top wall is parallel or deflected. Furthermore, a channel with the circular ramp is considered. The numerical solution is achieved by the finite volume method or by the finite element method. The results of both numerical approaches are compared.

关键词： backward facing step flow EARSm model SST model

Influence of Water Pollution on mIC of Stainless Steel 304L

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Journal of Iron and Steel Research International 2002年第2期9卷 45-48页

作者： LING Yun CHEN z G GUEmPL P KAESSER m Jiangsu University of Science and Technology Zhenjiang 212013 China Jiangsu University of Science and Technology Zhenjiang 212013 China Industrial University of Konstance Konstance Germany Industrial University of Konstance Konstance Germany

Crystallization kinetics of pr 8Fe 86 x zr x B 6 ( x =0, 1, 2) amorphous alloys was studied by DTA and XRD methods. The experimental results showed that the crystalline phases of pr 8Fe 86 B 6 alloy are composed of α Fe phase, pr 2Fe 23 B 3 and pr 2Fe 14 B, when crystallization temperature is below 900 ℃. The activation energy of α Fe phase remains relatively constant about 306.09 kJ/mol, as the crystalline fraction of α Fe phase is below 8 %. At the beginning of crystallization, the activation energy of pr 2Fe 23 B 3 and pr 2Fe 14 B phases are 510.85 kJ/mol and 725.97 kJ/mol, respectively, and then the activation energy of three phases declines with increasing the crystalline fraction. The crystallization behavior of α Fe and pr 2Fe 14 B essentially results in the formation of a α Fe/pr 2Fe 14 B composite microstructure with a coarse grain size in annealed pr 8Fe 86 B 6 alloy, which is attributed to a difficult nucleation and an easy growth for both the α Fe and pr 2Fe 14 B in the alloy. zr can be used to change the crystallization behavior of the α Fe phase in pr Fe B amorphous alloy, which is helpful to the formation of the α Fe/pr 2Fe 14 B nanocomposite microstructure with a fine grain size for the α Fe phase in the alloy.

关键词： pr 8Fe86-x zr xB 6 amorphous alloy crystallization kinetics activation energy

Computational aerodynamic analysis on perimeter reinforced(pr)-compliant wing

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Chinese Journal of Aeronautics 2013年第5期26卷 1093-1105页

作者： N.I.Ismail A.H.zulkifli m.z.Abdullah m.Hisyam Basri Norazharuddin Shah Abdullah Faculty of mechanical Engineering Universiti Teknologi MARA40450 Shah AlamSelangorMalaysia School of mechanical Engineering Universiti Sains MalaysiaEngineering Campus14300 Nibong TebalPenangMalaysia School of materials and mineral Resources Engineering Universiti Sains MalaysiaEngineering Campus14300 Nibong TebalPenangMalaysia

Abstract Implementing the morphing technique on a micro air vehicle （mAV） wing is a very chal- lenging task, due to the mAWs wing size limitation and the complex morphing mechanism. As a result, understanding aerodynamic characteristics and flow configurations, subject to wing structure deformation of a morphing wing mAV has remained obstructed. Thus, this paper presents the investigation of structural deformation, aerodynamics performance and flow formation on a pro- posed twist morphing mAV wing design named perimeter reinforced （pr）-compliant wing. The numerical simulation of two-way fluid structure interaction （FSI） investigation consist of a quasi- static aeroelastic structural analysis coupled with 3D incompressible Reynolds-averaged Navier- Stokes and shear-stress-transport （RANS-SST） solver utilized throughout this study. Verification of numerical method on a rigid rectangular wing achieves a good correlation with available exper- imental results. A comparative aeroelastic study between pr-compliant to pr and rigid wing per- formance is organized to elucidate the morphing wing performances. Structural deformation results show that pr-compliant wing is able to alter the wing＇s geometric twist characteristic, which has directly influenced both the overall aerodynamic performance and flow structure behavior. Despite the superior lift performance result, pr-compliant wing also suffers from massive drag penalty, which has consequently affected the wing efficiency in general. Based on vortices investigation, the results reveal the connection between these aerodynamic performances with vortices formation on pr-comoliant wing.

关键词： Aerodynamics Aeroelasticity Fluid structure interaction micro air vehicle (mAV) morphing wing

A quantitative microplasticity-based approach to rationalize the poor strengthening response of polycrystalline mg alloys

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Journal of magnesium and Alloys 2023年第5期11卷 1656-1671页

作者： X.z.Jin W.C.Xu D.B.Shan B.Guo B.Jin m.T.Pérez-prado National Key Laboratory for precision Hot processing of metals&School of materials Science and Engineering Harbin Institute of TechnologyHarbin 150001PR China ImDEA materials Institute C/Eric Kandel2GetafeMadrid 28906Spain Advanced Composites Simulation Lab University of Southern CaliforniaLos AngelesCA 90089U.S.A m.C.Gill Composites Center University of Southern CaliforniaLos AngelesCA 90089U.S.A

This work aims to understand the inefficiency of nanoprecipitates to strengthen a weakly textured,polycrystalline mg-Gd-Y-zr *** experimental micromechanical approach consisting on micropillar compression combined with analytical electron microscopy is put in place to analyze the effect of nanoprecipitation on soft and hard basal slip and twinning in individual grains with different *** study shows that,in grains that are favorably oriented for basal slip(“soft”basal slip),aging leads to extreme localization due to the ability of basal dislocations to shear the nanoparticles,resulting overall in the softening of basal ***,in grains in which the c-axis is almost perpendicular to the compression axis,prismatic slip dominates deformation in the solid solution state and nanoprecipitation favors twinning due to the concomitant lattice solute ***,in grains oriented with their c-axis making an angle of about 5-7°with respect to the compression axis,which deform mainly by“hard”basal slip,precipitation leads to the strengthening of basal systems in the absence of obvious *** work reveals that the poor hardening response of the polycrystalline alloy is related to the capability of basal dislocations to shear the nanoparticles,in the absence of Orowan looping events,and to the associated basal slip localization.

关键词： magnesium precipitation Basal slip Particle shearing Slip localization

An In Vitro model of Perineural Invasion of Adenoid Cystic Carcinoma

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An In Vitro Model of Perineural Invasion of Adenoid Cystic C...

microstructure and mechanical properties of mg-3.0Nd-0.4zn-0.4zr magnesium alloy

第八次全国口腔颌面—头颈肿瘤会议

作者： Shao z Shang zJ (Department of Oral and maxillofacial Surgery,School and Hospital of Stomatology,Wuhan University,Wuhan,pr China)

Background & Objectives:preineural invasion is the major mechanism of adenoid cystic carcinoma(ACC) spread outside the salivary *** is understood regarding mechanisms of perineural invasion in *** present an in vitro model to observe the interaction between nerves and ACC ***:mouse dorsal root ganglia(DRG) and human ACC-m cell lines were co-cultured in matrigel *** cultures consisted ACC cells only and DRG *** outgrowth,cell colony growth,neurite-cell contact,and retrograde extension were quantitated with dark phase microscopy.A modified mTT assay and Transwell assays were performed to determine the proliferation and migration alteration of ACC cells using the conditioned media from perineural invasion model. Results:Directional outgrowth of neurites was observed projecting into ACC-m colonies within 72 hr of *** the contact was established neurite growth diminished,suggesting an active attraction between neutrie and ACC ***,ACC cells migrated along neurites in a retrograde fashion into nerve establishing perineural *** addition to perineural invasion,ACC-m colony growth was elevated in regions near the DRG rclative to regions fra away from the DRG in *** conditioned media from perineural invasion model could induce the ACC cells survival and ***:This study shows the in vitro model of perineural invasion of adenoid cystic *** model can be used to study specific mechanism of ACC cell-nerve interaction. These data suggest that the process of perineural invasion involve active and reciprocal interactions between ACC cells and nerves and ACC cells acquire a survival and migration advantage by contact with neuritis.

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Journal of magnesium and Alloys 2014年第1期2卷 85-91页

作者： L.H.Wen z.S.Ji m.L.Hu H.Y.Ning machinery and Electric Department Heilongjiang Institute of Technology999 Hongqi StreetHarbin 150050PR China School of materials Science and Engineering Harbin University of Science and Technology4 Linyuan RoadHarbin 150040PR China

mg-3.0Nd-0.4zn-0.4zr magnesium alloy were prepared by cast-extruding and ***,tensile and creep properties of the alloy were *** results show that the alloy exhibit particle dynamic recrystallization during *** cast extruded-T6 rods at room temperature have a highest tensile strength of 258.5 mPa and a highest yield strength of 135.7 *** the increase of test temperature,the strength of the alloy declines and the elongation *** 473 K,creep strain in the primary creep stage increases with increasing the creep *** 110 mPa,time spent during primary creep decreases with increasing the test *** exponent and creep activation energy of the alloy are 4.4 and 104 kJ/mol,*** of the alloy can be controlled by dislocation climb *** morphology of the fracture surfaces was examined by employing scanning electron microscope.

关键词： mg-3.0Nd-0.4zn-0.4zr alloy Hot extrusion microstructure properties Fracture behavior