SILAS CARDOSO DOS SANTOS
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Artigo IPEN-doc 23196 Bio-prototyping of europium-yttria based rods for radiation dosimetry2017 - SANTOS, S.C.; RODRIGUES JUNIOR, O.; CAMPOS, L.L.The application of solid state dosimeters in radiation protection has grown significantly as consequence of advances in the development of dosimetric materials using rare earths. The conception of new dosimetric materials concerns synthesis methods, which control the evolution of material structure, including further processing steps as, shaping, drying, and sintering. The present study reports a full bio-prototyping approach to produce europium doped yttria rods with potential application in radiation dosimetry. Ceramic particles synthesized by hydrothermal route were characterized by Photon Correlation Spectroscopy (PCS), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). The effect of europium on promoting electronic defects in yttria host was evaluated by Electron Paramagnetic Resonance (EPR). Low pressure hydrothermal synthesis led to formation of rounded particles with mean diameter of 410 nm. Aqueous suspensions with 20 vol% of particles prepared at pH 10, and 0.2 wt% binder exhibited apparent viscosity of 213 mPa s, being suitable for bio-prototyping of rods. Sintering of shaped samples at 1600 degrees C for 4 h provided formation of dense ceramic rods. Europium-yttria rods containing 5 at.% Eu exhibited the most intense EPR response.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 19522 A viscoelastic approach from 'alfa'-Alsub(2)Osub(3) suspensions with high solids content2013 - SETZ, LUIZ F.G.; SILVA, ANTONIO C.; SANTOS, SILAS C.; MELLO CASTANHO, SONIA R.H.; MORELLI, MARCIO R.