RAFAEL HENRIQUE LAZZARI GARCIA

Resumo

Ao se formar no Colégio Bandeirantes, em 1998, realizou parte do curso de graduação em Ciências Sociais pela USP (2000 e 2001) e graduou-se em Ciências Com Habilitação Em Química nas Faculdades Oswaldo Cruz (2000 a 2003). Desempenhou parte da iniciação científica no IPEN em 2001, na área de Química Ambiental, e foi bolsista no agrupamento de processos químicos do IPT, de 2001 a 2004, aonde trabalhou com cristalização e caracterização de matérias primas industriais. Obteve o grau de Mestre, em 2007, no Instituto de Pesquisas Energéticas e Nucleares, na Universidade de São Paulo, estudando cerâmicas para células a combustível SOFC, e o grau de Doutor, em 2019, na área de caracterização de combustíveis nucleares. Em 2007, realizou visitas técnicas a centros de pesquisas no Japão, como parte do programa de Intercâmbio de Grupos de Estudo, patrocinado pela Fundação Rotária. De 2008 a 2010 foi professor voluntário no curso de alfabetização de adultos promovido pelo Rotary Liberdade. Atualmente é pesquisador do Instituto de Pesquisas Energéticas e Nucleares, no Centro de Combustíveis Nucleares, responsável pelos laboratórios de fluorescência e difração de raios X, e estuda combustíveis para reatores do tipo MTR. (Texto extraído do Currículo Lattes em 4 maio 2023)

Projetos de Pesquisa
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Resultados de Busca

Agora exibindo 1 - 10 de 23
  • Artigo IPEN-doc 31156
    Polymeric membranes grafted by ionizing radiation for uranium adsorption
    2024 - CARDOSO, A.C.P.; GARCIA, R.H.L.; CARVALHO, E.F.U.; AL SHEIKHLY, M.; KODAMA, Y.
    Fuel elements production by IPEN-CNEN has a perspective to be increased to attend Brazilian Multipurpose Reactor, under construction. This production generates liquid waste that requires proper treatment to minimize environmental impacts, promoting more sustainable practices. Considering the rise on nuclear power energy generation, and that there is global lack of terrestrial uranium sources, the increasing demand for this element has been leading to uranium exploit alternatives. So, several researches are available on uranium adsorption from sea water. Adsorption is one of process for removing metals from wastewater, due to its high selectivity and low environmental impact. Taking into account this scenary, in this study, Winged Polypropylene (WPP) fabric was grafted via ionizing radiation (RIG) with the monomer Bis[2-(methacryloyloxy) ethyl] phosphate (B2MP). RIG promotes functionalization of WPP with phosphate groups that are prone to capture U from solution. Synthesized WPP-g-polyB2MP membranes were characterized by Scanning electron microscopy (SEM), Raman spectroscopy, thermogravimetry and, uranium adsorption capacity by ICP-OES and gamma spectrometry. WPP-g-polyB2MP membranes were successfully synthesized by ionizing radiation grafting direct method. Reaction parameters, like reactants concentration, radiation absorbed dose, affected the degree of grafting (DoG). By physico-chemical characterization results it was possible to observe DoG differences with parameters variation. Optimization of these parameters was sought in order to achieve uranium adsorption, and to increase the adsorption capacity of the membrane.
  • Artigo IPEN-doc 30663
    Polymeric membranes grafted by ionizing radiation for uranium adsorption
    2024 - CARDOSO, A.; GARCIA, R.L.; CARVALHO, E.F.U. de; AL SHEIKHLY, M.; KODAMA, Y.
  • Artigo IPEN-doc 30646
    Radiation Induced Graft polymerization (RIG) of B2MP onto nylon fabric for uranium adsorption
    2024 - CARDOSO, A.C.P.; GARCIA, R.H.L.; CARVALHO, E.F.U. de; AL SHEIKHLY, M.; KODAMA, Y.
  • Artigo IPEN-doc 30621
    A purification process for the tetrauranium fluoride effluent
    2024 - GARCIA, R.H.L.; KODAMA, Y.; CARVALHO, E.F.U.; RIELLA, H.G.; SCHAFFER, D.; CONTURBIA, G.C.
  • Artigo IPEN-doc 26323
    Adsorção líquida no siliceto de urânio
    2019 - OLIVEIRA, VITORIA A.; CARVALHO, ELITA U.; DURAZZO, MICHELANGELO; SAKATA, SOLANGE K.; GARCIA, RAFAEL H.L.
    O siliceto de urânio é um intermetálico usado como combustível nuclear na maioria dos reatores de pesquisa modernos, incluindo os reatores MB-01 e IEA-R1 do IPEN. Durante a produção, o material é submetido a um rigoroso controle de qualidade, que inclui análises de tamanho de partícula, densidade, caracterização e composição da fase cristalina. A quantificação das fases cristalinas presentes é realizada por difração de raios X (DRX) e refinamento dos dados usando o método Rietveld. No entanto, devido à alta absorção de raios X por esse material, no que diz respeito ao método de quantificação adotado, é muito importante reduzir o tamanho das partículas. Para este objetivo, um moinho vibratório dedicado é usado antes da análise de DRX, reduzindo o diâmetro médio das partículas para poucos micrômetros. Para evitar a oxidação das amostras, o processo de moagem ocorre em meio isopropanóico, o qual é seco posteriormente, em vácuo a 80 ºC. Porém, em muitos casos, verifica-se que as massas das amostras moídas são maiores do que as iniciais. Nesse sentido, esse trabalho propõe analisar a causa dessa diferença de massa. Granulometria a laser, termogravimetria (TG). Os resultados de TG sugerem que uma camada é fortemente adsorvida ao material, protegendo o pó de oxidação em temperaturas acima de 4000C.
  • Artigo IPEN-doc 24335
    Analysis of slag formation during UF4 magnesiothermic reduction
    2017 - DURAZZO, MICHELANGELO; SALIBA-SILVA, ADONIS M.; GARCIA, RAFAEL H.L.; CARVALHO, ELITA F.U. de; RIELLA, HUMBERTO G.
    Metallic uranium is a fundamental raw material for producing nuclear fuel elements for research reactors and irradiation targets for producing 99Mo, as U3Si2, UMo alloy, UAlx, and uranium thin foils. Magnesiothermic reduction of UF4 is a possible route in the nuclear fuel cycle for producing uranium as a metal ingot. The main concern about the reducing scale to produce low-enriched (metallic) uranium (LEU) (around 1 kg) is the relatively low yield compared to calciothermic reduction. Nevertheless, the magnesiothermic reduction has the advantages of having lower cost and being a safer method for dealing with uranium processing. The magnesiothermic process, as a batch, is closed inside a sealed crucible. In the present study, in order to have a qualitative idea of the kinetics during the ignition moment, the slag projected over the lateral inner face of the crucible was used to sketch the general magnesiothermic evolution. The methods used were metallographic observation and X-ray diffraction followed by Rietveld refinement. The results of these analyses led to the conception of a general reaction development during the short time between the ignition of the reducing reaction and final settlement of the products. Relevant information from this study led to the conclusion that uranium is not primarily present in the lateral slag projection over the crucible during the reaction, and the temperature level may reach 1500°C or more, after the ignition.
  • Artigo IPEN-doc 24357
    Production of uranium tetrafluoride from the effluent generated in the reconversion via ammonium uranyl carbonate
    2017 - SILVA NETO, JOAO B.; CARVALHO, ELITA F.U. de; GARCIA, RAFAEL H.L.; SALIBA-SILVA, ADONIS M.; RIELLA, HUMBERTO G.; DURAZZO, MICHELANGELO
    Uranium tetrafluoride (UF4) is the most used nuclear material for producing metallic uranium by reduction with Ca or Mg. Metallic uranium is a raw material for the manufacture of uranium silicide, U3Si2, which is the most suitable uranium compound for use as nuclear fuel for research reactors. By contrast, ammonium uranyl carbonate is a traditional uranium compound used for manufacturing uranium dioxide UO2 fuel for nuclear power reactors or U3O8-Al dispersion fuel for nuclear research reactors. This work describes a procedure for recovering uranium and ammonium fluoride (NH4F) from a liquid residue generated during the production routine of ammonium uranyl carbonate, ending with UF4 as a final product. The residue, consisting of a solution containing high concentrations of ammonium (NH4 þ), fluoride (F ), and carbonate (CO3 2 ), has significant concentrations of uranium as UO2 2þ. From this residue, the proposed procedure consists of precipitating ammonium peroxide fluorouranate (APOFU) and NH4F, while recovering the major part of uranium. Further, the remaining solution is concentrated by heating, and ammonium bifluoride (NH4HF2) is precipitated. As a final step, NH4HF2 is added to UO2, inducing fluoridation and decomposition, resulting in UF4 with adequate properties for metallic uranium manufacture.
  • Resumo IPEN-doc 18445
    Study of the crystallinity of the intermetallic compound U3Si2, used as nuclear fuel, by synchrotron radiation diffraction
    2012 - ICHIKAWA, R.U.; MARTINEZ, L.G.; SILVA, R.S.S.; RIELLA, H.G.; CARVALHO, E.F.U.; CONTUBIA, G.; GARCIA, R.H.L.; IMAKUMA, K.
  • Resumo IPEN-doc 18419
    Microstructural characterization of UF4 by high-resolution synchrotron diffraction
    2012 - ICHIKAWA, R.U.; MARTINEZ, L.G.; SILVA, R.S.S.; RIELLA, H.G.; CARVALHO, E.F.U.; CONTUBIA, G.; GARCIA, R.H.L.; IMAKUMA, K.
  • Artigo IPEN-doc 18494
    Uranium electrodeposition for irradiation targets
    2012 - SALIBA-SILVA, A.M.; GARCIA, R.H.L.; BERTIN, E.; URANO de CARVALHO, E.F.; DURAZZO, M.