简介：Multiphaseflowcontrolwithelectromagneticbraking(EMBr)iswidelyusedinthecontinuouscastingofsteelslabs.Thebasicaimoftheflowcontrolsystemoftheprocessistodelivermoltensteelfromtheladlethroughthetundish,uppertundishnozzle,slidegate,andsubmergedentrynozzleintothemoldregionwithminimaldefects.Thisrequirestheoptimizationofturbulencelevelsatameniscustoavoidbothanexcessivelyfastflow(whichcreateshighfluctuationsofthemeniscuslevelinadditiontoslagentrapment,surfacenonuniformities,andsurfacedefects)andinsufficientslowflow(whichleadstomeniscussolidification,inadequatefluxinfiltration,andsurfacedefects).Inthisstudy,aEulerian-LagrangianapproachisusedtoinvestigatetheeffectsofEMBrandArbubbleinjectiononthesurfaceflowvelocity.TheresultsshowthathighArinjectionratescanleadtoanincreaseinsurfacevelocity.

简介：1IntroductionThesupplyofconventionalpetroleumisdecreasingwhileheavyoilresourcesintheworldexceed600milliontons,soheavyoilwillbecomeanimportantenergysourceinthe21stcentury.

简介：Theanalysisofthesolutionoffluidnetworkmodeliscarriedouttomatchtheneedofgraphicallymodularauto-modellingforpowerplantsimulatorsbecauseofthesymmetryandsparsityofthelinearsystemofequations,anewmethodofimprovedGausseliminationispresentedforthesolutionoflargescalematrices.ComparisonofthenewmethodwiththeclassicalGausseliminationmethod,theGauss-Seideliterativemethodaregiven.Theresultsshowthatthealgorithmprovidedisbetterthantheothersandissuitableforauto-modellingoffluidnetowrksofpowerplants.

简介：Wepresentthesimulationofthedynamicsoffluid-cylinderinteractionsinanarrowthree-dimensionalchannelfilledwithaNewtonianfluid,usingaLagrangemultiplierbasedfictitiousdomainmethodologycombinedwithafiniteelementmethodandanoperatorsplittingtechnique.Asexpected,asettlingtruncatedcylinderturnsitsbroadsideperpendiculartothemainstreamdirectionandthecenterofmassmovestothecentralaxisofthechannel.Inthecaseoftwotruncatedcylinders,theyfirstmovearoundeachotherforawhileandthenstaytogetherina"T"shape.Afterthe"T"shapehasbeenformedforalongenoughtime,wefoundnovortexsheddingbehindthecylinders.Whensimulatingthefluidizationof60truncatedcylinders,wecapturedthefeaturesofinteractionsamongfluidizedcylindersasobservedinexperiments.

简介：Osteocytesactasmechanosensorsinbone,whichcansendmechanicalsignalsdirectlytoosteoblaststhroughgapjunctions.However,underphysiologicalconditionsthenumberofgapjunctionsislimitedbecauseofthequantityvarianceofthetwokindsofcells.Inthisstudy,thepossibilityofindirectinteractionbetweenthesetwocellswasinvestigated.Anewflowchamperwasdesignedinwhichosteocytesandosteoblastswerecoculturedintwochampersseparately.OsteocyteswereexposedtofluidflowandthentheALPactivity,osteocalcinandosteopotinofosteoblastsweredetermined.TheresultsshowedthateitherALPactivityorproductionofosteocalcinandosteopotininosteoblaststhatwerecoculturedwithshearedosteocytesincreased,whichindicatedthatosteocytescouldregulateosteoblastsindirectlythroughsomesolublefactors.

简介：Vibrationofacircularmembraneincontactwithafluidhasextensiveapplicationsinindustry.Thenaturalvibrationfrequenciesfortheasymmetricfreevibrationofacircularmembraneincontactwithaboundedincompressiblefluidarederivedinthispaper.Consideringsmalloscillationsinducedbythemembranevibrationinanincompressibleandinviscidfluid,thevelocitypotentialfunctionisusedtodescribethefluidfield.Twoapproachesareusedtoderivethefreevibrationfrequenciesofthesystem,whichincludeavariationalformulationandanapproximatesolutionemployingtheRayleighquotientmethod.Agoodcorrelationisfoundbetweenfreevibrationfrequenciesevaluatedbythesemethods.Finally,theeffectsofthefluiddepth,themassdensity,andtheradialtensiononthefreevibrationfrequenciesofthecoupledsystemareinvestigated.

简介：Thechaotictransientsofacurvedfluidconveyingtubesubjectedtoanonlinearfoundationareinvestigated.TheassumptionoftheinextensibilityofthetubeisappliedtoderivethenonlineardifferentialequationofmotionviatheNewtonianapproach,withthedifferentialquadraturemethodusedtodiscretizethecurvedtubemodelinthespatialdomain.Andthenonlineardynamicmotionequationisobtained.Thenumericalanalysisshowsthat,thefinalsteadystatesaresensitivetotheinitialsystemconditionsinalargeparameterregionofthefluidspeed.Thisphenomenonofchaotictransientsisinfrequentforfluidconveyingtubes.

简介：Theuniquecharacteristicsofgas-solidstwo-phaseflowandfluidizationintermsoftheflowstructuresandtheapparentbehaviorofparticlesandfluid-particleinteractionsarecloselylinkedtophysicalpropertiesoftheparticles,operatingconditionsandbedconfigurations.Fluidizedbedsbehavequitedifferentlywhensolidproperties,gasvelocitiesorvesselgeometriesarevaded.Anunderstandingofhydrodynamicchangesandhowthey,inturn,influencethetransferandreactioncharacteristicsofchemicalandthermaloperationsbyvariationsingas-solidcontact,residencetime,solidcirculationandmixingandgasdistributionisveryimportantfortheproperdesignandscale-upoffluidizedbedreactors.Inthispaper,ratherthanattemptingacomprehensivesurvey,weconcentrateonexaminingsomeimportantpositiveandnegativeimpactsofparticlesizes,bubbles,clustersandcolumnwallsonthephysicalandchemicalaspectsofchemicalreactorperformancefromtheengineeringapplicationpointofviewwiththeaimofforminganadequateconceptforguidingthedesignofmultiphasefluidizedbedchemicalreactors.

简介：Inthispaper,anequationsystemofelectrohydrodynamics(EHD)basedonthefluidmotionequationsisdiscussed.Emphasisisputontheeffectsofelectricalforceandsurfacetensionuponthefluidmotion.TheMarkerandCellmethodisusedtosetupacomputationalsimulationprogramofelectricallydrivenmotionoffluid.Withthehelpoftheprogram,acylindricalfluidundertheinfluencesofelectricalfieldandsurfacetensionhasbeencalculated.Theresultisingoodagreementwiththeexperimentalobservation.

简介：Objective:Theexpressionofvascularendothelialgrowthfactor(VEGF)iscorrelatedtotheinvasionandmetastasisoftumorcellsinmanyclinicalcarcinomas.Inthisstudy,wedetectedsolubleVEGFlevelsinascitesandperitonealfluidandexploreditsclinicalsignificance.Methods:Atotalof91sampleswerecollectedanddividedinto5experimentalgroups:petitonealfluidofpatientswithbenign(n=10)andmalignantdisease(n=14),cirrhoticascites(n=36),tuberculousascites(n=8)andmalignantascites(n=23).Usingasandwichenzyme-linkedimmunoadsorbentassay,theconcentrationofsolubleVEGFwasmeasuredinascites(n=67)andpetitonealfluid(n=24).Results:VEGFlevelsinmalignantasciteswere640.74(264.81pg/ml,significantlyhigherthanthoseincirrhoticascites,tuberculousascitesandperitonealfluidofpatientswithbenignandmalignantdisease(P<0.01,separately).However,thedifferenceofVEGFlevelsamongthelatter4groupshadnostatisticsignificance(P>0.05),separately).Furthermore,VEGFlevelsinmalignantascitesfrompatientswithovariancancerwerehigherthanthosewithgastricandcoloncancer(P<0.01,respectively),whiletherewasnosignificantdifferencebetweengastriccancerandcoloncancer(P>0.05).UsingVEGFlevelof118.96pg/mlasaminimumcutofflimit,thesensitivityandspecificityofVEGFofthisassaytodiagnosemalignantasciteswere91.3%and73.9%respectively.Conclusion:TheelevatedlevelsofVEGFmaybeusefulasanindexindifferentialdiagnosisofbenignandmalignantascites.ItappearsthatVEGFplaysanimportantroleinmalignantascitesformation.

简介：Thisworkinvestigatestheflowofathirdgradefluidinarotatingframeofreference.Thefluidisincompressibleandmagnetohydrodynamic(MHD).Theflowisboundedbetweentwoporousplates,thelowerofwhichisshrinkinglinearly.Mathematicalmodellingoftheconsideredflowleadstoanonlinearproblem.Thesolutionofthisnonlinearproblemiscomputedbythehomotopyanalysismethod(HAM).Graphsarepresentedtodemonstratetheeffectofseveralemergingparameters,whichclearlydescribetheflowcharacteristics.

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简介：Anexactsolutionisdevelopedforthetimeperiodicelectroosmoticflowofanon-Newtonianfluidbetweenthemicro-parallelplates.TheconstitutiveequationsofageneralizedBurgersfluidareusedinthemathematicalformulation.TheresultingproblemissolvedbyaFouriertransformtechnique.Graphsareplottedanddiscussedforvariousemergingparametersofinterest.

简介：ThesedimentationofcircularparticlesinaverticalchannelfilledwithOldroyd-BfluidwasstudiedbyanimprovedDistributedLagrangeMultiplier/fictitiousdomain(DLM)method.Thesedimentingbehaviorsoftwoparticlesarepresentedfirstly,whichshowsthat,whentheparticlesaredroppedinaviscoealsticfluid,thestableconfigurationistheonewheretheparticlesarealignedparalleltotheflowdirectionwhentheMachnumberMislessthan1andtheelasticitynumberEisgreaterthan1.ThisagreeswellwiththeknownexperimentalinRef.[1]andsimulationresultsinRef.[2].Oursimulationsalsoshowthat,asinNewtonianfluid,thesedimentationoftheparticleswillbeacceleratedduetotheinteractionbetweenparticlesinaviscoealsticfluid.

简介：目的:对现有的关于研究水合状态对运动员身体活动能力影响的证据进行批判性分析。方法:从多个数据库检索获取符合纳入标准的文献,随后采用唐斯和布莱克协议(DownsandBlackprotocol)对纳入文献进行批判性评估。结果:9篇文章符合入选标准,平均79%在方法论质量上代表高标准的研究。结论:证据表明在持续30s以上的活动中,脱水状态在身体表现中有消极作用:然而在少于15s的持续运动中,脱水状态对身体表现并无显著影响。

简介：ThesedimentationsoftwocylindricalparticlesinthreedifferentinitialrelativepositionsarenumericallysimulatedusingthelatticeBoltzmannmethod.Themovementcharacteristicsandparticleinteractionsduringtheirsedimentationarepresentedanddiscussedindetail.Theresultsshowthat,(i)ifthetwoparticlesarereleasedparallelbutseparatedhorizontally,theypushawayeachother,rotateinwardsandseparatehorizontallyastheyfall;(ii)ifthetwoparticlesarereleasedparallelbutseparatedvertically,thesedimentationbehaviorcanbeclassifiedintothreestages:trailing,tumblingandseparating;(iii)ifthetwoparticlesarereleasedperpendicularbutseparatedvertically,thesedimentationbehaviorcanbecharacterizedas:trailingandrotating,touchingandsliding.Inordertovalidateoursimulation,experimentswerealsoconductedandtheresultsagreewellwiththenumericalones.

简介：基于连续统的有限变丑理论和poroelastic理论，为在自然、起始的坐标的浸透液体的多孔的媒介(FSPM)的acoustoelastic理论被开发在波浪速度上调查有效压力和液体毛孔压力的影响。第一，在FSPM的大部分静态的变丑前上附加的一个小动态运动的假设产出自然、起始、最后的配置，谁的排水量，紧张，和压力稳固骨骼并且在一个FSPM粒子的液体能分别地在自然、起始的坐标被描述。第二，从运动和FSPM的非线性的组成的关系的介绍的最后状态的方程的平衡的起始状态的方程的减法为小动态运动导致运动的方程。第三，同类的变丑前的考虑和小动态运动的飞机泛音形式给一个acoustoelastic方程，它为快纵的波浪的关系提供分析明确的表达，快砍波浪，慢砍波浪，并且有稳固骨骼的压力和液体毛孔压力的慢纵的波浪。最后，在靠近毛孔的jacketed条件，开毛孔的jacketed条件，传统的unjacketed条件，和triaxial状况下面的各向同性的FSPM作为一个例子被拿讨论速度快并且慢砍沿着起始的主要稳固骨骼的紧张之一的方向宣传的波浪。详细讨论证明FSPM的波浪速度被有效压力和液体毛孔压力通常影响。仅仅，液体毛孔压力在FSPM的波浪速度上有小效果应用起始的主管的部件稳固骨骼强调或紧张是相等的，它与以前的试验性的结果一致。

简介：AfluidbuffermodelwithMarkovmodulatedinput-outputratesisconsidered.Whentrafficintensityisnearitscriticalvalue,thesystemisknownasinheavytraffic.Itisshownthatasuitablyscaledsequenceoftheequilibriumbuffercontentshasaweakordistributionallimitunderheavytrafficconditions.ThisweaklimitisafunctionalofadiffusionprocessdeterminedbytheMarkovchainmodulatingtheinputandoutputrates.Thefirstpassagetimeofthereflectedprocessisexamined.ItisshownthatthemeanfirstpassagetimecanbeobtainedviaasolutionofaDirichletproblem.ThenthetransitiondensityofthereflectedprocessisderivedbysolvingtheKolmogorovforwardequationwithaNeumannboundarycondition.Furthermore,whenthefastchangingpartofthegeneratoroftheMarkovchainisaconstantmatrix,therepresentationoftheprobabilitydistributionofthereflectedprocessisderived.Upperandlowerboundsoftheprobabilitydistributionarealsoobtainedbymeansofasymptoticexpansionsofstandardnormaldistribution.

简介：这篇论文基于inviscid和imcompressible液体和无旋的流动在液体/结构影响上论述工作的评论。焦点在和边界元素方法(BEM)的速度潜力理论上。充分非线性的边界条件在未知免费表面和动人的身体的弄湿的表面上被强加。评论包括(1)在常数或规定变化速度的身体的垂直、倾斜的水入口，以及免费秋天运动，(2)液体微滴或列影响以及波浪影响身体，(3)膨胀身体的类似答案。它盖住二维(2D)，axisymmetric并且三维(3D)盒子。在数字模拟使用的关键技术被构画出，包括multivalued上的网孔产生免费表面，为扩展域的拉长的坐标系统，压力的相互的依赖和身体打手势的为去耦的辅助函数方法，并且为喷气或薄液体电影的处理在影响期间发展了。

简介：Thepresentpaperisfocussedontheeffectsofviscousandturbulentshearstressesonbothverticalvelocityandconcentrationdistributionsinlargesuspensionofsands.Whentheflowcarrieslargeamountofsedimentsinsuspension,thepropertiesoffluidmixturearechangedintermsofmodifiedviscosity,densityandfallvelocity,andhencetheflowcharacteristics.Theoreticalmodelshavebeendevelopedforbothvelocityandconcentrationprofiles,takingintoaccounttheviscousandturbulentshearstresses,whicharethefunctionofvolumetricconcentration.Comparisonoftheoreticalmodelswithexperimentaldatarevealsthat(i)themodifiedvelocityandconcentrationprofilesagreewellwiththeobserveddataforhighsuspension,(ii)thehigherthesedimentsuspension,thesmallerthevonKarmanconstant,and(iii)sedimentdiffusioncoefficientislessthanmomentumdiffusioncoefficientforfinesandsinsuspension.