简介:Becauseoflimitedresourceofembeddedplatforms,thecomputationalcomplexityofadvancedcontrolalgorithmsraisessignificantchallengesfortheuseofembeddedsystemsincomplexcontrolfield.AScilab/Scicosbasedembeddedcontrollerisdevelopedonwhichvariouscontrolsoftwarecanbeeasilymodeled,simulated,implemented,andevaluatedtomeettheever-expandingrequirementsofindustrialcontrolapplications.BuiltontheCirrusLogicEP9315ARMsystems-on-chipboard,thisembeddedcontrollerispossibletodevelopcomplexembeddedcontrolsystemsthatemployadvancedcontrolstrategiesinarapidandcost-efficientfashion.Duetothefreeandopensourcenatureofthesoftwarepackagesused,thecostoftheembeddedcontrollerisminimized.
简介:Horizontalimpedancefunctionsofinclinedsinglepilesaremeasuredexperimentallyformodelsoil-pilesystemswithboththeeffectsoflocalsoilnonlinearityandresonantcharacteristics.Twopracticalpileinclinationsof5掳and10掳inadditiontoaverticalpileembeddedincohesionlesssoilandsubjectedtolateralharmonicpileheadloadingsforawiderangeoffrequenciesareconsidered.Resultsobtainedwithlow-to-highamplitudeoflateralloadingsonmodelsoil-pilesystemsencasedinalaminarshearboxshowthatthelocalnonlinearitieshaveaprofoundimpactonthehorizontalimpedancefunctionsofpiles.Horizontalimpedancefunctionsofinclinedpilesarefoundtobesmallerthantheverticalpileandthevaluesdecreaseastheangleofpileinclinationincreases.Distinctvaluesofhorizontalimpedancefunctionsareobtainedforthe'positive'and'negative'cyclesofharmonicloadings,leadingtoasymmetricforce-displacementrelationshipsfortheinclinedpiles.Validationoftheseexperimentalresultsiscarriedoutthroughthree-dimensionalnonlinearfiniteelementanalyses,andtheresultsfromthenumericalmodelsareingoodagreementwiththeexperimentaldata.Sensitivityanalysesconductedonthenumericalmodelssuggestthattheconsiderationoflocalnonlinearityatthevicinityofthesoil-pileinterfaceinfluencetheresponseofthesoil-pilesystems.
简介:Aseriesof3wt%Ruembeddedonorderedmesoporouscarbon(OMC)catalystswithdifferentporesizeswerepreparedbyautoreductionbetweenrutheniumprecursorsandcarbonsourcesat1123K.RunanoparticleswereembeddedonthecarbonwallsofOMC.CharacterizationtechnologiesincludingpowerX-raydiffraction(XRD),nitrogenadsorption-desorption,transmissionelectronmicroscopy(TEM),andhydrogentemperature-programmedreduction(H2-TPR)wereusedtoscrutinizethecatalysts.ThecatalystactivityforFischer-Tropschsynthesis(FTS)wasmeasuredinafixedbedreactor.Itwasrevealedthat3wt%Ru-OMCcatalystsexhibitedhighlyorderedmesoporousstructureandlargesurfacearea.Comparedwiththecatalystswithsmallerpores,thecatalystswithlargerporeswereinclinedtoformlargerRuparticles.These3wt%Ru-OMCcatalystswithdifferentporesizesweremorestablethan3wt%Ru/ACcatalystduringtheFTSreactionsbecauseRuparticleswereembeddedonthecarbonwalls,suppressingparticlesaggregation,movementandoxidation.ThecatalyticactivityandC5+selectivitywerefoundtoincreasewiththeincreasingporesize,however,CH4selectivityshowedtheoppositetrend.ThesechangesmaybeexplainedintermsofthespecialenvironmentoftheactiveRusitesandthediffusionofproductsintheporesofthecatalysts,suggestingthattheactivityandhydrocarbonselectivityaremoredependentontheporesizeofOMCthanontheRuparticlesize.
简介:Anumericalstudyofanon-Darcymixedconvectiveheatandmasstransferflowoveraverticalsurfaceembeddedinaporousmediumundertheefectsofdoubledispersion,melting,andthermalradiationisinvestigated.Thesetofgoverningboundarylayerequationsandtheboundaryconditionsistransformedintoasetofcouplednonlinearordinarydiferentialequationswiththerelevantboundaryconditions.ThetransformedequationsaresolvednumericallybyusingtheChebyshevpseudospectralmethod.Comparisonsofthepresentresultswiththeexistingresultsintheliteraturearemade,andgoodagreementisfound.Numericalresultsforthevelocity,temperature,concentrationprofiles,andlocalNusseltandSherwoodnumbersarediscussedforvariousvaluesofphysicalparameters.
简介:Theinfluenceofinitialstrainstateonthedynamicresponseofanendbearingpileembeddedinisotropicsaturatedsoilisinvestigatedthroughthelinearizedtheoryofsmallelasticperturbationsuperposedonlargelystressedbodies.Thegoverningequationsforsoil,basedonBiot’sporoelasticitytheory,arederivedinthecylindricalcoordinates,andthepileismodeledbyusingtheone-dimensionalelastictheory.Theanalyticalsolutionsofpileimpedance,frequencyresponseofbothtwistangleandtimehistoryofvelocityresponseareobtainedbyusingofseparationofvariablestechnique.Finally,aparametricstudyoftheinfluenceofinitialstrainsonthetorsionalimpedance,twistangle,andvelocityresponseatthetopofthepileiscarriedout.