SILAS CARDOSO DOS SANTOS
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Artigo IPEN-doc 23921 Yttria nettings by replica processing2014 - SANTOS, S.C.; YAMAGATA, C.; ACCHAR, W.; MELLO-CASTANHO, S.R.H.In the context of green economy supported and widespread by United Nations (UN), the renewable energy sources are the unique mechanism to universalize the access to energy. Face to this strategic direction of change is essential to develop efficient components for saving energy such as porous ceramics that associate light with mechanical strength. Thus, the objective of this work concerns to improve the homogeneity of porous size distribution of yttria porous ceramics by evaluating their morphology during replica processing. Samples were subject to immersion into 30vol% yttria aqueous suspensions during an interval from 1min to 120min and sintered through careful thermal conditions. Based on the results, the weight and morphology of porous structure samples were directly influenced by immersion time, whereby intervals from 30-120min showed the best final products.Artigo IPEN-doc 22838 Processing, microstructure and thermoluminescence response of biomorphic yttrium oxide ceramics2016 - SANTOS, S.C.; YAMAGATA, C.; CAMPOS, L.L.; MELLO-CASTANHO, S.R.H.The present work reports a fast-direct bio-prototyping process using Luffa Cylindrica vegetable sponge to produce biomorphic yttrium oxide ceramics with reticulated-porous architecture and thermoluminescence response. Processing parameters as rheology of yttrium oxide suspensions, bio-template surface treatment and thermal decomposition of bio-template were investigated. Shear thinning suspensions of 30 vol% yttrium oxide with apparent viscosity of 243mPa.s provided a successful impregnation of samples, whereby bio-templates with smooth ceramic layer and hierarchical reticulated architecture were formed. By thermal treatment at 1600 degrees C for 2 h biomorphic yttrium oxide ceramics with porous microstructure and TL response at 150 degrees C and lambda=550 nm were produced. The proposed fast direct bio-prototyping process is suitable for the production of ceramic components with complex shape and demonstrates potential for general applicability to any bio-template. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.Artigo IPEN-doc 22509 Processing and thermoluminescent response of porous biomorphic dysprosium doped yttrium disilicate burner2016 - SANTOS, S.C.; YAMAGATA, C.; CAMPOS, L.L.; MELLO CASTANHO, S.R.H.Artigo IPEN-doc 21769 Bio-prototyping and thermoluminescence response of cellular rare earth ceramics2016 - SANTOS, S.C.; YAMAGATA, C.; CAMPOS, L.L.; MELLO CASTANHO, S.R.H.The use of renewable materials is essential toward green economy. Vegetable structures are abundant, exhibit complex hierarchically built shape and an architecture that is promising to form functional materials. In this work using a mixture of rare earth oxides, which contain around 57 wt% yttrium oxide, cellular ceramics by bio-prototyping from the vegetable sponge Luffa cylindrica were produced and the thermoluminescence response was evaluated. By colloidal processing aqueous suspensions with 25 vol% solids content, pH 10, 1 wt% deffloculant and 0.2 wt% binder exhibited shear thinning behavior and apparent viscosity suitable for replica method. By thermal treatment at 1600 ◦C for 2 h in air biomorphic rare earth ceramics with dense microstructure and reticulated architecture were produced.Artigo IPEN-doc 20312 Lighting by biogas burners: Perspectives on development in Brazil2014 - SANTOS, SILAS C.; YAMAGATA, CHIEKO; MELLO CASTANHO, SONIAArtigo IPEN-doc 16255 Rheological behaviour of yttria aqueous suspensions for impregnation method2010 - SANTOS, S.C.; YAMAGATA, C.; MELLO CASTANHO, S.R.H.Artigo IPEN-doc 16254 Rare earth porous membranes by colloidal processing2010 - SANTOS, S.C.; MELLO CASTANHO, S.R.H.Rare earth porous membranes (RePM) were manufactured by colloidal processing and impregnation method. Ceramic suspensions based on rare earth concentrated (ReC) with 25vol% were prepared. The rheological behavior of ceramic suspensions as function of solid load and binder concentration was evaluated by flow curves with shearing rate interval from 0 to 1000s-1. A nyloncotton netting (NC) was selected as template. Impregnated NC templates were subjected to a careful thermal treatment seeing that burning off the organic template could induce sensible residual stress and disrupting the ceramic structure. Sintering at 1600ºC/15h the morphology of RePMs were like NC templates and presented a good handle strength.Artigo IPEN-doc 15843 Obtencao de membranas porosas a base de terras raras por processamento coloidal2010 - SANTOS, S.C.; MELLO CASTANHO, S.R.H.Artigo IPEN-doc 18384 Análise reológica de suspensões cerâmicas concentradas: abordagem viscoelástica2012 - SETZ, L.F.G.; SILVA, A.C.; SANTOS, S.C.; MELLO CASTANHO, S.R.H.; MORELLI, M.R.Artigo IPEN-doc 19175 Yttrium disilicate stability in aqueous medium2013 - SANTOS, S.C.; ACCHAR, W.; SILVA, A.C.; YAMAGATA, C.; MELLO CASTANHO, S.R.H.