CECILIA CHAVES GUEDES E SILVA

CECILIA CHAVES GUEDES E SILVA

(Fonte: Lattes)

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Possui graduação em Engenharia de Materiais pela Universidade Presbiteriana Mackenzie (1997), mestrado em Tecnologia Nuclear Aplicações pelo Instituto de Pesquisas Energéticas e Nucleares (2000) e doutorado em Tecnologia Nuclear Materiais pelo Instituto de Pesquisas Energéticas e Nucleares (2005). Atualmente é pesquisador do Instituto de Pesquisas Energéticas e Nucleares. Tem experiência na área de Engenharia de Materiais, atuando principalmente nos seguintes temas: materiais cerâmicos, biomateriais e materiais nucleares. (Texto extraído do Currículo Lattes em 08 out. 2021)

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Influence of silicon, strontium and aluminum oxides on silicon nitride ceramics for bone replacements
2020 - NASCIMENTO, SERGIO F. do; RODAS, ANDREA C.D.; CARVALHO, FLAVIO M. de S.; HIGA, OLGA Z.; SILVA, CECILIA C.G. e
Although silicon nitride ceramics have been shown very propitious to be used for bone replacements, some characteristics can be controlled to improve their osseointegrations process. One of them is the intergranular phase whose composition can be specified to stimulate mineralization and osteoblastic production. In this paper, the intergranular glassy phase was projected in order to contain silicon, strontium and aluminum oxides. Silicon nitride samples containing different contents of SiO2, SrO and Al2O3 were sintered at 1815oC for 1 hour and characterized by scanning electron microscopy and X-ray diffraction. Hardness and fracture toughness were determined by Vickers hardness test and compressive strength was evaluated using an universal material testing machine. The biological behavior was studied in regard to cytotoxicity and cell proliferation by means of in vitro experiments. The samples reached high densities (higher than 95 %TD), total α→β-Si3N4 transformation, fracture toughness higher than 6.5 MPa.m1/2, compressive strength up to 2500 MPa and Vickers hardness less than 9.8 GPa. All samples were non-cytotoxic and able to promote cell proliferation with great potential to be used as components for bone replacements. However, that sample with high content of strontium had the best results of cell proliferation, proving the importance of a careful choice of intergranular phase composition in silicon nitride ceramics.
Influence of alumina phases on the molybdenum adsorption capacity and chemical stability for 99Mo/99mTc generators columns
2016 - GUEDES-SILVA, C.C.; FERREIRA, THIAGO dos S.; CARVALHO, FLAVIO, M.S.; PAULA, CAROLINA M. de; OTUBO, LARISSA
Technetium-99m is the clinically most used radionuclide worldwide. Although many techniques can be applied to separate 99Mo and 99mTc, the most commonly used method is the column chromatography with alumina as stationary phase. However, the alumina nowadays used has limited adsorption capacity of molybdate ions which implies the need to develop or improve materials to produce high specific activity generators. In this paper, alumina was obtained by a solid state method and heat treatments at different conditions. The powders had a microstructure with porous particles of γ, δ, θ and α-Al2O3 phases as well as specific surface area between 36 and 312 m2 g-1. Most interesting results were reached by powders calcined at 900oC for 5 hours which had high chemical stability and a molybdenum adsorption capacity of 92.45 mg Mo per g alumina.
Formation of aluminium titanate with small additions of MgO and SiOsub(2)
2016 - GUEDES SILVA, CECILIA C.; CARVALHO, FLAVIO M. de S.; FERREIRA, THIAGO dos S.; GENOVA, LUIS A.
Influence of additive system (aLSUB(2)oSUB(3)-reSUB(2)oSUB(3), re=y,lA,nD.dY,yB) on microstructure and mechanical properties of silicon nitride-based ceramics
2009 - MARCHI, JULIANA; GUEDES e SILVA, CECILIA C.; SILVA, BRUNO B.; BRESSIANI, JOSE C.; BRESSIANI, ANA H. de A.