AUREA BEATRIZ CERQUEIRA GERALDO

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Licenciada e bacharel em Química pela Universidade Federal do Paraná (1991), mestre em Físico-Química pela Universidade Estadual de Campinas (1993) e doutora em Engenharia Metalúrgica e de Materiais pela Universidade Federal do Rio de Janeiro (1998). Atualmente é tecnologista do Instituto de Pesquisas Energéticas e Nucleares. Atua principalmente nos seguintes temas: a) eletroquímica: eletroanalítica, eletrodissolução/eletrodeposição, b) materiais modificados por radiação: modificação e caracterização de materiais poliméricos, caracterização de materiais ligados a radioisótopos, estudo e caracterização de materiais para a produção de radioisótopos primários e c) ensino de química (Texto extraído do Currículo Lattes em 4 out. 2021)

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Agora exibindo 1 - 7 de 7
  • Resumo IPEN-doc 26555
    Effect of ionizing irradiation on tilapia (Oreochromis niloticus) skin
    2011 - FROSE, C.A.P.; MOURA, E.; YAMAGUISHI, R.B.; SOMESSARI, E.S.R.; SILVEIRA, C.G.; LEME, E.; GERALDO, A.B.C.; MANZOLI, J.E.
    The culture of tropical tilapia (Oreochomis niloticus), as a non-native freshwater fish specie in Brazil, have had importance in the last decade due its fast growing, fast reproduction characteristics, high tolerance of climate variations in our country and high disease resistance. The high demand of whole fish or fillets is related to its good taste. Althought, its skin, that represents from 4.5 % to14 % of fish weight, is a byproduct that is generally discared or sold at low cost to feed mills. The general animal skin composition comprises protein, water, minerals and fatty matter where the relative portions of these materials depends of upon animal specie, age, breed, feeding and other animal habits. The putrecible raw animal skins can be chemically and physically treated to make it in non-putrecible stabilized material; it results in a soft and flexible polymeric material. The chemical process to obtain this material generally involves a crosslinking of carboxyl groups or amino groups of skin proteins and the chemical reactive specie [1]. Also, physical process as UV irradiation have been successfully employed to crosslink collagenous biomaterials and thus, improved some mechanical characteristics [2]. The goal of this work was to study the tilapia skins exposed to ionizing irradiation from electron beams. The raw skins and the chemically degreased skins were the studied materials. The tensile strenght and elongation at break were the mechanical parameters evaluated. The optical microscopy was used to evaluate some histological characteristics in irradiated and non-irradiated samples. Also, the polymeric product obtained when skins are treated with oxidizing ions were used to compare some results. The tilapia raw skins were kindly available by APTA, a governmental agribusiness technological agency. These skins were scales free, slighted and frosted. The skins were irradiated in atmosphere air on a Job 188 Dynamitron® Electron Beam Accelerator with 1.5 MeV energy under comprised doses of 20 kGy and 40 kGy and dose rates of 2.2 kGy/s and 7.4 kGy/s. The mechanical parameters were measured at a Lloyd LXR tensile tester at a crosshead speed of 10.00 mm/min. Irradiated samples shows high integrity and high tensile strength in comparison to the polymeric product obtained by oxidizing ions reaction. These results are discussed.
  • Artigo IPEN-doc 24187
    Study of bixin oxidation by ionizing irradiation
    2017 - FONSECA, THAIS N.; TEIXEIRA, PAULA S.; MOURA, EDUARDO de; GERALDO, AUREA B.C.
    Brazil is the world's largest producer of anatto, followed by Kenya and Peru. The fruit of the annatto tree is constituted by a capsule containing external spines and internal seeds with reddish coloration, providing a natural pigment which is environmentally efficient, being able to replace synthetic pigments and dyes. The active substance of the pigment is Bixin, which is a type of carotenoid which constitutes a greater percentage of pigment in these seeds and has a lipo soluble character. Bixin reacts with NaOH in a saponification reaction giving norbixin, which is water soluble. It is known that the destination of the dye extracted from the fruit is intended for industry, especially the food industry. The culture of annatto tree brings prospects of development in agricultural programs for medium and small producers, which are able to use decadent areas of other crops. In addition to the food sector, new applications for the pigment helps the development of family farming. The pigment extracted from annatto undergoes a natural oxidation; this work aims to evaluate this phenomenon and also the oxidation of the pigment after the irradiation process. This work also evaluates of the how the oxidation process is affected by irradiation and the modifications introduced to irradiated pigments. Irradiated and nonirradiated samples were characterized by thermogravimetry, UV-vis spectrophotometry and infrared spectroscopy (FTIR). The results are then discussed.
  • Artigo IPEN-doc 22778
    In vitro study of the composition and microhardness of the hard tissues from oral cavity submitted to gamma irradiation
    2016 - PAREDES, WILBER E.B.; ARI, SANDRA F.; GERALDO, AUREA B.C.; ANDRADE, DELVONEI A. de
    Introduction: Clinical Radiotherapy is one of the most important techniques for the treatment of malignant lesions of the head and neck, however, exposure to ionizing radiation can lead to systemic complications or sites during and after radiation treatment. Among these immediate local complications in oral cavity, it stands out the xerostomia and consequent oral mucositis. Regarding late complications produced by radiation, decay of radiation and osteoradionecrosis, both dose-dependent lesions, which mostrate a high level of incidence in recent decades (1-30%) and unwieldy, although these are presented after completion of treatment and under the influence of local factors. Methodology: The methodology proposed in this study aims to examine the direct effect of ionizing radiation after gamma irradiation of enamel, root dentin and jawbone samples, through the dose rate used in patients suffering with head and neck cancer. The samples were analyzed by microhardness surface analysis, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR) before and after irradiation. Results and discussion: The data were analyzed statistically with a significance level of 95% (p <0.05%), through the parametric Student's t-test for related averages and ANOVA statistical test, finding a statistically significant result (p = 0.00) for the four groups of samples. Conclusion: From the statistical results, it is concluded that the effect of gamma radiation on hard tissues of the oral cavity was highly significant regarded to physical, compositional and morphological properties.
  • Artigo IPEN-doc 21149
    Evaluation of electron beam irradiation under heating process on vulcanized EPDM
    2015 - GABRIEL, LEANDRO; CARDOSO, JESSICA R.; MOURA, EDUARDO; GERALDO, AUREA B.C.
  • Resumo IPEN-doc 20585
    Irradiation process applied in fishs scales: in improvement of its capacity for metallic sorption
    2014 - BAZANTE YAMAGUISHI, RENATA; GERALDO, AUREA B.C.; MOURA, EDUARDO
  • Artigo IPEN-doc 19470
    Ionizing radiation as optimization method for aluminum detection from drinking water samples
    2013 - BAZANTE YAMAGUISHI, RENATA; GERALDO, AUREA B.C.; MOURA, EDUARDO; MANZOLI, JOSE E.
  • Artigo IPEN-doc 17180
    Polymerization of tilapia (Oreochromis niloticus) skin by electron beam irradiation
    2011 - FROSE, CAMILA A.P.; MOURA, EDUARDO; YAMAGUISHI, RENATA B.; SOMESSARI, ELISABETH S.R.; SILVEIRA, CARLOS G.; LEME, EDNILSE; GERALDO, AUREA B.C.; MANZOLI, JOSE E.