ANDRE SANTOS BARROS DA SILVA
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Artigo IPEN-doc 25848 X-ray diffraction analysis of KY3F10 nanoparticles doped with Nd and preliminary studies for its use in high-dose radiation dosimetry2019 - ICHIKAWA, R.U.; LINHARES, H.M.S.M.D.; SILVA, A.S.B. da; TEIXEIRA, M.I.; RANIERI, I.M.; TURRILLAS, X.; MARTINEZ, L.G.In this work, the structure and microstructure of Nd:KY3F10 nanoparticles was probed using X-ray synchrotron diffraction analysis. Rietveld refinement was applied to obtain cell parameters, atomic positions and atomic dis-placement factors to be compared with the ones found in literature. X-ray line profile methods were applied to determine mean crystallite size and crystallite size distribution. Thermoluminescent (TL) emission curves were measured for different radiation doses, from 0.10 kGy up to 10.0 kGy. Dose-response curves were obtained by area integration beneath the peaks from TL. The reproducibility of the results in this work has shown that this material can be considered a good dosimetric material.Dissertação IPEN-doc 25462 Desenvolvimento de ferramentas computacionais para análise de perfis de difração de raios X2018 - SILVA, ANDRÉ S.B. daNeste trabalho foi desenvolvido um conjunto de ferramentas computacionais, em linguagem de programação Python, para a análise de perfis de difração de raios X, tanto para o estudo quanto para obtenção dos valores microestruturais como tamanhos médios de cristalitos e microdeformações, através de dos métodos de: Scherrer, Single-Line, Williamson-Hall e Warren-Averbach. Para aplicar os métodos de análise de perfis, foram também implementados métodos de remoção da contribuição instrumental pelo método de Stokes e ajuste de funções, remoção de ruídos pelo método de Savitzky-Golay, correção da radiação de fundo pelo método de ajuste linear, correção do fator de Lorentz-Polarização e correção do dubleto Kalfa2 .Artigo IPEN-doc 24174 X-ray diffraction analysis of KY3F10 nanoparticles doped with Nd and preliminary studies for its use in high-dose radiation dosimetry2017 - ICHIKAWA, RODRIGO U.; LINHARES, HORACIO M.S.M.D.; SILVA, ANDRE S.B. da; TEIXEIRA, MARIA I.; RANIERI, IZILDA M.; TURRILLAS, XAVIER; MARTINEZ, LUIS G.In this work, the structure and microstructure of Nd:KY3F10 nanoparticles was probed using X-ray synchrotron diffraction analysis. Rietveld refinement was applied to obtain cell parameters, atomic positions and atomic displacement factors to be compared with the ones found in literature. X-ray line profile methods were applied to determine mean crystallite size and crystallite size distribution. Thermoluminescent (TL) emission curves were measured for different radiation doses, from 0.10kGy up to 10.0kGy. Dose-response curves were obtained by area integration beneath the peaks from TL. The reproducibility of the results in this work has shown that this material can be considered a good dosimetric material.Artigo IPEN-doc 24172 Structural and microstructural analysis of the U-GD-O system using X-ray diffraction data2017 - DARIN, GASPAR; IMAKUMA, KENGO; MARTINEZ, LUIS G.; TURRILAS, XABIER M.; ICHIKAWA, RODRIGO U.; SILVA, ANDRE S.B.; DURAZZO, MICHELANGELO; RIELLA, HUMBERTO G.; URANO, ELITAGadolinium is one of the best neutron absorber materials and its usage can be considered as a burnable poison for Light Water Reactors (LWR) and as a sacrificial material in Sodium Fast Reactor (SFR). Most of the experiments in the literature focus on nuclear fuel with up to 12 wt% Gd2O3. Recently, the phase diagram and melting point has been investigated for high contents of Gd2O3 in the U-Gd-O system, that means a solid solution of the composition (U1-x, Gdx)O2 for 0