MARIA DA CONCEICAO COSTA PEREIRA

MARIA DA CONCEICAO COSTA PEREIRA

(Fonte: Lattes)

ScopusID

ResearcherID

Resumo

Possui graduação em Química Industrial pela Escola Superior de Química Oswaldo Cruz (1984), Mestrado pelo Instituto de Pesquisas Energéticas e Nucleares - USP (1997) e Doutorado pelo Instituto de Pesquisas Energéticas e Nucleares - USP (2006). Atualmente é pesquisadora do Instituto de Pesquisas Energéticas e Nucleares. Possui experiência na área de Química e Engenharia Nuclear, atuando principalmente nos seguintes temas: detectores de radiação, tempo de decaimento de luminescência, cintilação e crescimento de cristais cintiladores inorgânicos. Orientadora de Mestrado (Texto extraído do Currículo Lattes em 16 nov. 2021)

Página do item completo

Resultados de Busca

Agora exibindo 1 - 3 de 3

Determination of the bromine, manganese and antimony in Nicotiana tabacum solanaceae by using the neutron activation analysis technique
2022 - MADI FILHO, TUFIC; FERREIRA, ELSON B.; BERRETTA, JOSE R.; PEREIRA, MARIA da C.C.
Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability. Smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have conducted research about heavy metals and the toxicity of tobacco. It is, frequently, found in low concentrations in the ground, and superficial and underground waters, even though they do not have environmental anthropogenic contributions. However, with the increase of industrial activities and mining together with the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of these materials increases and is released into the biosphere, where they are often accumulated in the superior layer of the ground, accessible to the roots of the plants. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used; consequently, the smoke from cigarette smoking presents various toxic substances, such as bromine (Br), manganese (Mn) and antimony (Sb), elements studied in this work. The procedures for the preparation of the samples were carried out in our laboratories and submitted to irradiation with thermal neutrons at Nuclear and Energy Research Institute (IPEN/CNEN-SP), in the Atomic Energy Institute IEA-R1 research reactor. The irradiated material was, then, analyzed by gamma spectrometry, using a high purity germanium detector (HPGe).
Characteristics of the CsI:Tl scintillator crystal for X-Ray imaging applications
2018 - PEREIRA, MARIA da C.C.; MADI FILHO, TUFIC; BERRETTA, JOSE R.; MESQUITA, CARLOS H. de
Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10−3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.
Scintillation characteristics of CsI crystal doped Br under gamma and alpha particles excitation
2014 - PEREIRA, MARIA da C.C.; MADI FILHO, TUFIC