简介:Thecompatibilitybetweendirectcoalliquefactionresidue(DCLR)andfivekindsofpurebitumen(Shell-90,SK-90,ZSY-70,DM-70andKLMY-50)wasevaluatedinthisstudy.Therheologicalcharacteristics,glasstransitiontemperatures(T_g),solubilityparameters(SP)andSARA(saturates,aromatics,resins,andasphaltenes)fractionsofDCLR,fivekindsofpurebitumenandtheirblends(namedasDCLRmodifiedbitumen)weremeasuredusingthedynamicshearrheometer(DSR),differentialscanningcalorimetry(DSC),viscosity,andSARAtests,respectively.AndthecompatibilitybetweenDCLRandpurebitumenwascharacterizedwiththreeapproaches,viz.theCole-Coleplot,T_g,andthesolubilityparameterdifference(SPD)method.Sinceeachmethodhasitsownworkingmechanism,thecompatibilityrankingfortheDCLRandfivekindsofpurebitumenisslightlydifferentaccordingtothethreeapproaches.However,thedifferenceisprettycloseandsometimescanbeignored.Thegeneralcompatibilityrankingdecreasesinthefollowingorder:Shell-90≈SK-90>DM-70≈ZSY-70>KLMY-50,whichisaffectedbytheasphaltenescontentandthecolloidindex(I_c)valueinthepurebitumen.Purebitumenwithlowerasphaltenescontentandcolloidindex(I_c)valuehasbettercompatibilitywithDCLR.
简介:Thedensityofasphaltwasmeasuredwiththepycnometeranddensitometer.Creeppropertiesoftheasphaltwereinvestigatedwiththebendingbeamrheometerattemperaturesrangingfrom0℃to-36℃.Theasphaltdensitydatausedtocorrelatewiththecreeppropertieswerecalculatedfromtheregressionequationofdensityandtemperature.TheasphaltsampleusedtodeterminethecreeppropertywasagedbythestandardRTFOTtestandthePAVtest.Thetestresultsshowedthattheasphaltdensityhadalinearrelationshipwithtemperaturechanges.Thelogarithmofthecreepstiffnessandtheslopeofthelogarithmofthestiffnessat60secondsalldemonstratedalinearrelationshipwiththedensity,andtheregressioncoefficientofthesedatawasaround0.99.Thecreepstiffnessandtheslopeofthecreepstiffnesscanbecalculatedfromtheasphaltdensityatthesametemperature.
简介:Inthispaper,anabinitio,localdensityfunctional(LDF)methodwasusedtoexploretherelationshipbetweenthemolecularpropertiesofadditivesandthelubricatingperformanceofaluminumrollingoil.Thestructuralpropertiesofbutylstearate,dodecanol,docosanol,andmethyldodecanoatewerestudiedaccordingtothedensityfunctionaltheory.Thecalculateddatashowedthattheatomsinoraroundthefunctionalgroupsmightbelikelythereactingsites.Becauseofthedifferentfunctionalgroupsandstructureofesterandalcohol,twotypesofcomplexadditives,dodecanolandbutylstearate,methyldodecanoateandbutylstearate,respectively,werechosenforstudyingtheirtribologicalpropertiesandperformingaluminumcoldrollingexperiments.Thetestresultsagreedwiththecalculatedresultsverywell.Thecomplexester,viz.methyldodecanoateandbutylstearate,hadthebestlubricatingperformancewithafrictioncoefficientof0.0841andapermissive-rollingthicknessof0.040mmascomparedwiththatofdodecanol-butylstearate-baseoilformulation.
简介:Thispaperhadinvestigatedtheeffectsofsurfacewettabilityonthefrictionalresistanceofturbulenthorizontalflowfortapwaterinfivepipesmadeofvariousmaterialsandfourkindsofliquidsinapolytetrafluoroethylene(PTFE)pipe,withthesameinnerdiameterof14mm.Pressuredropsweremeasuredunderdifferentflowratesthroughanexperimentalflowloop.Thecontactanglesandadhesionworkofliquidsincontactwithpipesurfacesweredeterminedusingacontactanglemeter.Basedonthedimensionandregressionanalyses,twokindsofmodifiedrelationshipsbetweenthefrictionalcoefficientandthesurfacewettabilitywereestablishedaccordingtothemeasuredresultscorrespondingtotapwaterinfivepipesandfourliquidsinPTFEpipe.Theexperimentalresultsshowthatthesurfacewettabilityhassomeinfluenceonfrictionalcoefficientofthestudiedliquidsflowinginmacroscalepipes,andthefrictionalcoefficientdecreaseswiththeincreaseofthecontactangleatthesameReynoldsnumber.Meanwhiletheeffectofwettabilityonthehydrophobicsurfaceisgreaterthanthatonthehydrophilicone.Thefrictionalcoefficientspredictedbythemodifiedformulashaveverifiedtobeingoodagreementwiththeexperimentalvalues,therelativeerrorsofwhicharewithin±6%and±3%forthetapwaterflowinginfivedifferentpipesandfourkindsofliquidsflowinginPTFEpipe,respectively.
简介:SixNi-MocatalystswithdifferentmetalcontentswerepreparedandcharacterizedbyN2adsorptionandX-raydiffractometry.TheactivephasemicrostructureofthesecatalystswasexaminedbytheRamanspectroscopy,temperatureprogrammedreduction(TPR),X-rayphotoelectronspectroscopy,andhigh-resolutiontransmissionelectronmicroscopy.Hydrodesulfurization(HDS)activityofcatalystsampleswereanalyzedinaflowfixed-bedmicroreactor.ThesulfidationdegreeofMoandthelengthoftheMoS2slabslightlyincreasedwiththeamountofmetalloadedfollowingsulfidation.Thissmallchangeisattributedtopolymolybdatespeciesobservedinalltheoxidizedcatalysts.Weakmetal-supportinteractions,asdeterminedbytheTPRtechnique,increasedtheNiSxsulfidationphaseandMoS2slabstacking.TheHDSactivityofthecatalystsamplesincreasedwiththenumberofactivesites.Forhighmetalloadingcatalysts,theirHDSactivitywasnearlyidenticalbecausethesulfuratomscannoteasilyapproachactivesites.ThischangeiscausedbythelargenumberofstackedlayersintheMoS2slabsaswellasthedecreaseinthespecificsurfaceareaandporevolumeofthecatalystsampleswithanincreasingmetalloading.