MARCELO FRANCIS MADUAR

Resumo

Doctorate (2010) and Master (2000) degrees in Nuclear Technology at São Paulo University, Physics Bachelorate at São Paulo University (1996) and Technologist in Data Processing at Universidade Estadual Paulista Júlio de Mesquita Filho (1989). Experience in Experimental Physics, focusing on Experimental Methods and Instrumentation for Elementary Particles and Nuclear Physics. (Text obtained from the Currículo Lattes on November 16th 2021)


Doutorado (2010) e Mestrado (2000) em Tecnologia Nuclear pela Universidade de São Paulo, Bacharelado em Física pela Universidade de São Paulo (1996) e graduação em Tecnologia Em Processamento de Dados pela Universidade Estadual Paulista Júlio de Mesquita Filho (1989). Tecnologista senior do Instituto de Pesquisas Energéticas e Nucleres (IPEN), órgão da Comissão Nacional de Energia Nuclear (CNEN). Gerente adjunto (desde julho/2018) do Serviço de Gestão de Radiometria Ambiental (SEGRA) do IPEN. Tem experiência na área de Física, com ênfase em Métodos Experimentais e Instrumentação para Detectores de Radiação, atuando principalmente nos seguintes temas: espectrometria gama, radioatividade ambiental e aplicação de métodos computacionais na avaliação de espectros gama, em modelos de dispersão ambiental e em dose externa decorrente de radiação gama. Orientador de Mestrado do Programa de Pós-Graduação em Tecnologia Nuclear do IPEN - área de Aplicações (TNA) a partir de maio de 2019 e docente das disciplinas TNA5754, Radioatividade no meio ambiente e avaliação de impacto radiológico ambiental, e TNA5733, Tópicos Avançados de Medidas Nucleares. (Texto extraído do Currículo Lattes em 16 nov. 2021)

Projetos de Pesquisa
Unidades Organizacionais
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Resultados de Busca

Agora exibindo 1 - 10 de 29
  • Artigo IPEN-doc 30655
    One year of Be-7 measurement in rainfall collected in different points in the city of São Paulo, Brazil
    2024 - DOMINGOS, R.M.; LEONARDO, L.; DAMATTO, S.R.; MIRANDA JUNIOR, P.; ISIKI, V.L.; NISTI, M.B.; ALENCAR, M.M.; TEIXEIRA, L.F.L.; MADUAR, M.F.; NETO, J.O.A.
  • Artigo IPEN-doc 30513
    Pb-210 activity concentration measured in rainfall in different sampling heights
    2024 - ALMEIDA NETO, J.O.; DAMATTO, S.R.; MADUAR, M.F.; LEONARDO, L.; TEIXEIRA, L.F.L.
  • Artigo IPEN-doc 28199
    Counting time optimization for gamma-ray spectrometry analysis
    2021 - NISTI, M.B.; MADUAR, M.F.; SAUEIA, C.H.R.; CAVALCANTE, F.
  • Artigo IPEN-doc 28198
    Counting efficiency in gamma ray spectrometry with different volumes for the same geometry
    2021 - NISTI, M.B.; MADUAR, M.F.; DAMATTO, S.R.; ALENCAR, M.M.
  • Artigo IPEN-doc 27080
    Radiochemical method for characterization of the filter cartridges from the IEA-R1 reactor
    2016 - GERALDO, BIANCA; VICENTE, ROBERTO; FERREIRA, ROBSON J.; MADUAR, MARCELO F.; GOES, MARCOS M.; MARUMO, JULIO T.
    The filter cartridges used in water purification system of the IEA-R1 research reactor become radioactive waste after the end of their useful life. The characterization of this waste is one step in their management, which aims at identifying and quantifying the radionuclides present, including those known as "difficult to measure" (DTM) radionuclides. Wastes from nuclear reactors contain fission and activation products and transuranic elements, only few of them emitting gamma radiation measurable by simple gamma spectrometry methods. In routine waste management activities, the concentrations of the DTM can only be estimated by indirect methods such as scaling factors. The method of the scaling factors uses empirically determined proportions between the concentrations of DTM radionuclides and that of easily measurable gamma emitters called key nuclides (KN), to calculate DTM concentrations. Determining the scaling factors for the filter cartridges is a hard task when the number of samples is large, not only because the preparation of samples is difficult but also because the number of radionuclides to analyze is large. If it can be demonstrated that DTM and KN are both distributed evenly in the filters, less samples from each filter are necessary, reducing lab work. The aim of this paper is to present the results of the assessment of homogeneity along the filter cartridges by gamma spectrometry of chemically reduced samples. Five thin slices of five filters were burnt and the ashes quantitatively dissolved and the activity concentration of the solutions determined by gamma spectrometry.
  • Artigo IPEN-doc 26206
    Gamma spectrometry of iodine-125 produced in IEA-R1 nuclear reator, using HPGe detector and fixation into epoxy matrix disc
    2019 - COSTA, OSVALDO L. da; SOUZA, DAIANE C.B. de; CASTANHO, FABIO G.; FEHER, ANSELMO; MOURA, JOÃO A.; SOUZA, CARLA D. de; OLIVEIRA, HENRIQUE B. de; MADUAR, MARCELO F.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.
    Few places in the world produce iodine-125. In Brazil, the first production happened in nuclear reactor IEA-R1 located at Nuclear and Energy Research Institute – IPEN. To verify the quality of iodine-125 produced, because contaminants as iodine-126, caesium-134 and caesium-137 among others, may be produced in irradiation process, iodine-125 samples were immobilized into epoxy matrix disc, with the same geometry of a barium-133 reference radioactive source, used to calibrate an HPGe detector. The HPGe detector has a thin carbon composite window, which allows measure the iodine-125 photopeaks, between 27.1 and 35.4 keV.
  • Artigo IPEN-doc 24079
    Natural radionuclides from U-238 and TH-232 series and inorganic chemical characterization of soil profiles and sediment cores of the Taiaçupeba Reservoir, São Paulo, Brazil
    2017 - SOUZA, J.M.; DAMATTO, S.R.; LEONARDO, L.; SURKOV, A.M.; SILVA, A.R.; MADUAR, M.F.; GONÇALVES, P.N.
    Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides 238U, 226Ra, 210Pb, 232Th, 228Th, 228Ra and 40K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides 40K and 228Th and the lowest for 210Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide 210Pb and the lowest for 226Ra and 228Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiacupeba reservoir.
  • Artigo IPEN-doc 22974
    Radiological implications of using phosphogypsum as building material
    2016 - MAZZILLI, BARBARA P.; MADUAR, MARCELO F.; NISTI, MARCELO B.; CAMPOS, MARCIA P. de
  • Artigo IPEN-doc 13900
    High strength phosphogypsum and its use as a building material
    2007 - KANNO, WELLINGTON M.; ROSSETTO, HEBERT L.; SOUZA, MILTON F. de; MADUAR, MARCELO F.; CAMPOS, MARCIA P. de; MAZZILLI, BARBARA P.
    A new process (patent applied) that works equally well with both plaster of mineral gypsum and phosphogypsum for the preparation of gypsum components, UCOS, has been developed. The process consists of the following steps: humidification of plaster by fine water droplets, uni-axial compression, hydration reaction and drying. Strong hydrogen bonds develop among the crystals together with adhesion provided by confined water that accounts for nearly 70% of the adhesion forces. By reducing the plaster to water ratio to close the minimum necessary, new features are generated. An experimental house has been constructed, in which walls and ceilings have been built of gypsum and phosphogypsum. Since phosphogypsum potentially contain radioactive elements, the application of an activity concentration index to the phosphogypsum employed in the building was carried out.
  • Artigo IPEN-doc 19395
    Natural gamma-ray emitters in clays used for therapeutic purposes
    2013 - MADUAR, MARCELO F.; PONCIANO, RICARDO; SILVA, PAULO S.C. da