简介：Ricehuskwasusedtopreparethesilicaofamorphousnaturebeingseveraltimesmorereactivethanthatobtainedfromthemineralkingdom.Numberofricehuskbatcheswerepyroprocessedundervaryingtime-temperatureparametersforthispurpose.Theashresultingfromabatchpyroprocessedat500℃for8hcontained92.01%silica.Itwasupgradedto98.50%byapplyingphysicochemicalpurificationprocedures.Themineral,wollastonite(CaSiO3),wassynthesizedfromthuspreparedsilicaandlimestonecontaining55.91%CaO.Solidstatereaction,betweenCaOandSiO2wasattemptedatdifferenttemperaturesinthepresenceofamineralizer.Thesinteringtemperature,foraffectingthesaidsynthesis,wasrangedbetween900℃to1300℃withthestepsof100℃.SpecificchemicalanalysistechniqueswereappliedtodeterminetheeffectivenessofcarriedoutreactionandpromisingbatchesweresubsequentlysubjectedtoXRDinvestigations.Theproducedmineralwasalsocharacterizedregardingitsphysicalpropertieslike:colour,hardness,meltingpointandspecificgravity.Percentyieldoftheproducedwollastonitewasalsoestimatedandcomparedwiththatofobtainedbyotherresearcherswhosynthesizeditbyusingsilicafrommineralkingdom.Batchessinteredat1200℃and1300℃for1hshowedtheoverallbestresults.

简介：Electrochemicalandcorrosionbehaviourofreinforcedsteelembeddedincementpastesincorporatingdifferentamountsofsilicafumeasapartialreplacementofcementhasbeenstudiedinchlorideandsulphatesolutionsbyusingdifferentelectrochemicaltechniques.Theresultsindicatethat,whilesteelpassivitydegreeislowinthecontrolsamples'uponsoakinginthecorrosivemedia,ithasbeenhighihsamplesincorporatingsilicafumeandincreasedwithincreasingsilicafumecontent.Theimprovementeffectofsilicafumemaybeattributedtotheporesolutionstructureofthecementpaste,whichlimitsthemobilityofaggressiveionsnearthesurfaceofthesteel.Themechanismofsteelcorrosionduetochlorideandsulphateattackandpassivationeffectofsilicafumearediscussed.

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简介：Thehydrothermalreactivityofsilicasandwasstudiedusingcementkilndust(CKD)asanactivatorinadditiontothePortlandcementfractionofEl-Karnakcement(ablendofordinaryPortlandcementandgroundsand).AutoclavedEl-Karnakcementpasteswerestudiedatpressuresof0.507,1.013and1.520MPaofsaturatedsteamwithrespecttotheircompressivestrength,kineticsofhydrothermalreactionandthephasecompositionoftheformedhydrates.TheroleofCKDinaffectingthephysicochemicalandmechanicalpropertiesofEl-Karnakcementpasteswasstudiedbyautoclavingofseveralpastescontaining5,7.5,10and20%CKDatapressureof1.013MPaofsaturatedsteam.CKDwasaddedeitherasarawCKD(unwashed)orafterwashingwithwater(washedCKD).TheresultsofthesephysicochemicalstudiesobtainedcouldberelatedasmuchaspossibletotheroleofCKD(raworwashed)inaffectingthehydrothermalreactivityofsilicasandinEl-Karnakcementpastes.

简介：在原处，有在硅石矩阵的柳酸(柳安)的铽建筑群的合成被一个二拍子的圆舞大音阶的第五音胶化过程做。有柳酸的铽建筑群在大音阶的第五音胶化被形成导出硅石胶化，并且由光刺激系列证实了并且红外线(红外)系列。作为与纯铽建筑群粉末相比，包含铽建筑群的硅石胶化展出它的典型排放并且为纯建筑群比那介绍更长的荧光一生。复杂包含硅石胶化的光性质被调查，与那些相比，两个，铽做了硅石胶化和纯复杂粉末。导致上述结果的原因也被讨论。(编辑作者摘要)7个裁判员。