IPEN: Recent submissions

  • IPEN-DOC 26192

    AQUINO, SIMONE ; LIMA, JOSE E.A. de; BORRELY, SUELI I. . Bioburden proliferation in vehicle air filters waste: the use of gamma radiation on fungal decontamination. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 999-1008.

    Abstract: This study aimed to analyze the fungal contamination of air-conditioning filters waste (n=20) as an indicator of Quality Air Indoor from different car models, that were collected from 10 exchange stations located in the South, North, West, Downtown and East, of the city of São Paulo in São Paulo State, Brazil, during the period from August 2018 to December 2018. A non-selective fungal agar was used, as a commercially prepared media. Sampling consisted of filters particles (33 fragments of 10 × 10-mm size) were plated onto solidified agar in Petri dishes in triplicate. The samples were incubated for seven days at 25 °C and were stored in a standard Biochemical Oxygen Demand (BOD) incubator, for growth of fungal cultures. After incubation, the fungal culture in the plates was evaluated, and the total counting of infected fragments was expressed as a percentage. The molds were examined by Lactophenol blue solution staining for microscopy. All samples were contaminated with various fungal genera, including Aspergillus, Alternaria, Cladosporium, and Penicillium. The study also aimed to evaluate the fungal enumeration in the samples that were irradiated with a dose of 10 kGy to fungal decontamination of air-conditioning filters waste. Of total samples, 50% were completed decontaminated, but yeasts, Cladosporium spp., Penicillium spp., Aspergillus niger demonstrated radioresistance at the dose of 10 kGy.

    Palavras-Chave: air conditioning; air filters; air quality; automobiles; cobalt 60; contamination; decontamination; fungi; wastes

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  • IPEN-DOC 26191

    SCHENEMANN, GISIELE ; FRANKLIN, ROBSON L.; FAVARO, DEBORAH I.T. . Metal, trace and rare earth elements assessment in a sediment profile from Taiaçupeba Reservoir, São Paulo state, by INAA. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 975-988.

    Abstract: The Taiaçupeba reservoir is located on the border of Mogi das Cruzes and Suzano counties and composes the Alto Tietê Producing System (SPAT). The region shows high population density and industrial production, which cause waste and contaminants generation, which can affect the water supply quality. The purpose of this study was to evaluate the concentration and distribution of As, Ba, Br, Co, Cr, Cs, Fe, Hf, K, Na, Rb, Sb, Sc, Ta, Th, U, Zn and the rare earth elements (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb), present in a sediment profile collected in the Taiaçupeba reservoir. Sampling was performed in 2016 by CETESB for monitoring purposes. Instrumental Neutron Activation Analysis technique was applied for multilemental determinations. A great variation of the concentration for the elements analyzed along the sediment profile was observed, with a concentration peak in the depth of 20cm for all elements and decreasing in the deepest slices. Enrichment factor (EF) and Geoacumulation Index (IGeo) tools used to evaluate the presence of anthropogenic pollution sources indicated As and Zn contamination, mainly in the more recent sediment samples (from 0 to 5 cm depth). When the concentration values for As, Cr and Zn were compared to TEL and PEL for quality sediment evaluation, none of the concentration values for As and Cr surpassed the PEL values but not Zn. The results showed that an important anthropogenic contribution for As, Cr and Zn in the upper layers of the sediment core is occurring.

    Palavras-Chave: aquifers; concentration ratio; elements; metals; neutron activation analysis; rare earths; sampling; sediments; trace amounts; brazil

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  • IPEN-DOC 26190

    GERALDO, RICARDO R.; PASCHUK, SERGEI A.; BARRETO, RAFAEL C.; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da ; SILVA, AMANDA C.M.da; NARLOCH, DANIELLE C.; ARAUJO, ISABELLE C.. Application of semi-empirical model for the evaluation of radium activity in phosphogypsum used as component of clinker. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 965-974.

    Abstract: Phosphogypsum is a residue that has been used by the cement industry as a substitute for the natural gypsum, used as a clinker additive during the production of Portland cement. There is a potential increase in this residue use since the large amount of phosphogypsum is generated as outcome of the phosphate fertilizer industries. However, phosphogypsum can be considered a source of radioactive contamination since it has 226Ra in its composition. Depending on the concentration of 226Ra, from the radiological protection point of view, this may cause a problem because this radionuclide and its direct decay product 222Rn along with other decay products, represent the largest fraction of radiation internal dose received by people. In order to evaluate the level of radiological risk that may be associated with the use of phosphogypsum, it is necessary to identify the concentration of 226Ra in building material. The aim of this research is to analyze the samples of phosphogypsum in relation to the concentrations of 226Ra, determined indirectly through 222Rn activity measurements. This measurement process has the advantage of being fast, convenient and relatively inexpensive when compared to traditional 226Ra concentration in samples measurement methods. Proposed physical-mathematical model was used to establish radium concentration from radon exhalation rate from cement mortar samples. The 222Rn activity measurements were performed with a portable detector with cubic phosphate samples with dimensions of 50x50x50mm3 allocated in a closed atmosphere of sampling chamber until secular equilibrium was reached. Obtained concentrations of radium activity in studied samples of phosphogypsum and cement mortars were found below the limits recommended by CNEN and international regulation.

    Palavras-Chave: concentration ratio; exhalation; gypsum cements; radiation detectors; radiation protection; radium 226; radon 222; brazilian cnen

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  • IPEN-DOC 26189

    THEOPHILO, CAROLINA Y.S. ; COLABUONO, FERNANDA I.; MONTONE, ROSALINDA C.; PETRY, MARIA V.; FIGUEIRA, RUBENS C.L.; MOREIRA, EDSON G. . Mercury and selenium concentrations study on Macronectes Giganteus feathers by instrumental neutron activation analysis. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 916-925.

    Abstract: Southern Giant Petrel (Macronectes giganteus) is a seabird species, from the Procelariiformes order. It has circumpolar distribution and can travel great distances from its breeding area to foraging areas, its diet is composed of fish, squid, crustaceans, carcasses of marine mammals and other birds. It is known that through food or environmental contamination any organism can assimilate different chemical elements. Some chemical elements are essential to metabolism, but some have no function and may end up causing adverse effects, such as Hg, which is considered one of the most toxic contaminants in the environment. The accumulation of Hg is a great danger due to the high potential of toxicity and transference capacity to the trophic web through bioaccumulation and biomagnification processes. Hg can affect the nervous, circulatory and endocrine systems, behavior, reproduction and embryo, in addiction, high concentrations can cause death. Due to the high toxicity of Hg and few studies about toxic elements in Southern Giant Petrel, this study aimed to quantify Hg in feathers of this seabird. The feathers were chosen for analysis because they can be collected without the need to sacrifice the birds. Instrumental Neutron Activation Analysis (INAA) was used for Hg and Se quantification. Hg concentrations ranging between 2.6 and 10.4 mg kg-1 and Se between 1.5 and 10.4 mg kg-1.

    Palavras-Chave: antarctic regions; biological accumulation; birds; concentration ratio; contamination; feathers; mercury; neutron activation analysis; selenium; toxicity

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  • IPEN-DOC 26530

    SCAGLIUSI, SANDRA R. ; CARDOSO, ELIZABETH C.L. ; LUGAO, ADEMAR B. . Butyl rubber recycling by means of gamma radiation followed by mechanical shear. International Journal of Waste Resources, v. 8, p. 53-54, 2018. DOI: 10.4172/2252-5211-C1-011

    Abstract: Polymeric materials (plastics and rubbers) cover a continuously raising proportion of urban and industrial solid wastes discarded in landfills and consequently their impact on environment are more and more concern. Rubbers exhibit a very slow natural decomposition due to their chemical structure weather resistant as well to enzymatic degradation and to microorganisms. Rubber recovering is hampered by its insolubility caused by crosslinked structures. Besides, this tridimensional structure causes various problems for material recovering and reprocessing. Just 8% to 12% of polymeric residues are thermoplastic polymers; remaining are elastomers especially post consumption tires. It is relevant to emphasize that the crosslinking is essential for practical use of rubber and this process is worldwide known as vulcanizing process, discovered by North American Charles Goodyear. The implementation of new technologies in order to reduce polymeric residues, acceptable from the environmental viewpoint and at an effective cost proved to be a great problem due to inherent complexities for polymers reuse. Ionizing radiation has capacity to change structure and properties of polymeric materials. Butyl rubbers have been used in wide scale within a variety of applications such as tires spare-parts and diverse artifacts. Major effect of high energy photon, such as gamma rays in butyl and halo-butyl rubbers is the creation of free radicals accompanied by changes in mechanical properties. This work aims to the development of processes of controlled degradation (de-vulcanizing) of butyl rubber in order to characterize their availability for modification and changes of their properties. Experimental results obtained showed that butyl rubbers irradiated at 25 kGy and further sheared can be used as the starting point for mixtures with pristine rubber.

    Palavras-Chave: rubbers; recycling; gamma radiation; ionizing radiations; environmental protection; shear; mechanical properties; tensile properties

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  • IPEN-DOC 26529

    CARDOSO, QUEZIA de A. ; CASINI, JULIO C.S.; BARBOSA, LUZINETE P. ; SERNA, MARILENE M. ; GALEGO, EGUIBERTO ; SOBRINHO, LUIZA F. ; SAKATA, SOLANGE K. ; FARIA JUNIOR, RUBENS N. de . X-ray diffraction evaluation of the average number of layers in thermal reduced graphene powder for supercapacitor nanomaterial. Materials Science Forum, v. 958, p. 117-122, 2019. DOI: 10.4028/www.scientific.net/MSF.958.117

    Abstract: Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. In this work, the thermal reduction of GO powder has been carried out using back pumping vacuum pressures and investigated employing X-ray diffraction analysis. The experimental results of estimating the number of graphene layers on the reduced powder at various temperatures (200 – 1000 °C) have been reported. Electrical changes have been produced in a graphene oxide with the vacuum reduction process. This study has shown that the ideal processing temperature for reducing graphene oxide nanomaterial was about 400 oC. It has also been shown that at 600 oC the number of layers in the reduced nanomaterial increased. The internal series equivalent resistance (ESR) has been improved substantially with the vacuum thermal treatment even at temperatures above 400 oC. ESR was reduced from 95.0 to about 13.8 Ω cm2 with this processing. These results showed that the process can be applied to the reduction of graphene oxide to produce supercapacitor nanomaterials. The advantage of employing this method is that the processing is a straightforward and low cost thermal treatment that might be used for large amount of nanocomposite material.

    Palavras-Chave: graphene; oxides; x-ray diffraction; vacuum systems; capacitors; capacitive energy storage equipment; nanomaterials; electrical properties

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  • IPEN-DOC 26528

    AGUIAR, V.A.P.; MEDINA, N.H.; ADDED, N.; MACCHIONE, E.L.A.; ALBERTON, S.G.; RODRIGUES, C.L.; SILVA, T.F.; ZAHN, G.S. ; GENEZINI, F.A. ; MORALLES, M. ; BENEVENUTI, F.; GUAZZELLI, M.A.. Thermal neutron induced upsets in 28nm SRAM. Journal of Physics: Conference Series, v. 1291, n. 1, p. 1-4, 2019. DOI: 10.1088/1742-6596/1291/1/012025

    Abstract: In this work, we present the rst results of static tests in a 28nm SRAM under thermal neutron irradiation from the IPEN/IEA-R1 research reactor. The SRAM used was the con guration memory of a Xilinx Zynq-7000 FPGA and the ECC frame was used to detect bit- ips. It was obtained a SEU cross-section of 9:2(21) 10􀀀16 cm2=bit, corresponding to a FIT/Mb of 12(5), in accordance with expected results. The most probable cause of SEU in this device are 10B contamination on tungsten contacts.

    Palavras-Chave: thermal neutrons; reactors; electronic equipment; irradiation devices; iear-1 reactor; research reactors; boron; fission

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  • IPEN-DOC 26188

    BARABÁS, CARLOS ; LIMA, ANA C. de S. ; SABUNDJIAN, GAIANE . Sustainability: the use of the Implicit Association Test (IAT) to identify and measure implicit attitudes. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 891-899.

    Abstract: Over the years, sustainability has been a major theme discussed by the leading environmental organizations around the world. Excessive consumption is one of the factors that is directly connected to environmental issues, interfering with the sustainability capacity of the Earth. Attitudes and behavior are influenced by both conscious (explicit) or unconscious (implicit) associations that subjects have in their memory. In order to identify unconscious associations, specific implicit memory tests are required, such as the Implicit Association Test (IAT), which is widely used to measure implicit associations towards several themes. This work aims to present the results from a pretest using the IAT to identify and measure the implicit associations of a group of environmental specialists regarding consumption and sustainability. By using the FreeIAT software, the IAT was customized for this research. The pretest with environmental specialists was conducted to check the consistency of the customized IAT. The Cronbach´s alpha was applied to measure the reliability of the test and showed good internal consistency. Since the results from the pretest with the specialists demonstrated that the customized IAT is reliable and consistent, this test can be applied to other groups of subjects to identify the implicit associations towards consumption and sustainability. The data obtained from the administration of the customized IAT will contribute to many research fields related to the environment, consumption, sustainability, energy and development.

    Palavras-Chave: computer codes; energy; environment; statistics; sustainability; sustainable development

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  • IPEN-DOC 26187

    SILVA, RITA de C.A. da ; SAIKI, MITIKO ; MOREIRA, EDSON G. ; OLIVEIRA, PAULO T.M.S.; THEOPHILO, CAROLINA Y.S. ; SANCHES, THAIS C.; COIMBRA, AMANDA A.; BIANCHI, TICIANA Z.D.. Trace elements in livers of great egrets (Ardea Alba) from São Paulo metropolitan region: temporal considerations (2006-2013) and the relations with sex and mass of birds. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 881-890.

    Abstract: To evaluate possible variations over time (2006-2013) in trace element levels in livers from adult specimens of great egret from the São Paulo Metropolitan Region (SPMR), recent data and published data have been used. The elements Br, Cl, Co, Cs, Cu, Fe, K, Mg, Mn, Na, Rb, Se and Zn were determined by Neutron Activation Analysis (NAA) and the toxic elements Cd and Hg by Atomic Absorption Spectrometry (AAS). The large inter annual variations observed for several elements showed the importance of expanding the time period for this analysis as the series is considered short (<10 years). However, non-significant increase of Br, Cu, Mn, Fe and Zn and a decrease in Cd, also non- significant, were observed at the end of the series. The concentration relations with sex and mass of the birds were also assessed. Females presented lower concentrations of Br, Co, Cs, Se and Zn and it may be related to metabolic differences, detoxification pathways, and other factors. No relationship between body mass and element levels were observed. Obtained results demonstrated the importance of temporal monitoring of trace elements in livers of great egrets, especially for the results obtained for Cu, Fe and Zn, since the contamination by these elements in the region should be considered. The present study is the first relating contaminant level with conditions of birds in the region, encouraging future studies that evaluate this issue.

    Palavras-Chave: absorption spectroscopy; aquatic organisms; birds; contamination; ecological concentration; elements; liver; neutron activation analysis; trace amounts

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  • IPEN-DOC 26527

    MORAIS, T.S.L. ; DIAS, M.S. . Study of induced activity of 167Ho from different neutron capture paths. Journal of Physics: Conference Series, v. 1291, n. 1, p. 1-4, 2019. DOI: 10.1088/1742-6596/1291/1/012024

    Abstract: The main purpose of this study is to predict the induced activity of 167Ho produced by 165Ho(n,γ)166mHo(n,γ)167Ho, 165Ho(n,γ)166Ho(n,γ)167Ho and 166mHo(n,γ)167Ho reactions to choose the best path to measure the cross section with lowest uncertainty. The activation and decay scheme was established starting from the 165Ho target and considering single, double and triple neutron capture reactions. The activity results were deduced from differential activation equations and decay rates for all reaction products. The calculations were performed considering samples which were taken from a stock solution supplied by the Electrotechnical Laboratory (Japan) for purposes of an international comparison.

    Palavras-Chave: holmium; holmium 167; holmium 165 reactions; holmium 165 target; activation analysis; decay; radioactivity; thermal neutrons

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  • IPEN-DOC 26521

    SANTOS, O.C.B.; LICHTENTHALER, R.; PIRES, K.C.C.; MORO, A.M.; UMBELINO, U.; ZEVALLOS, E.O.N.; ASSUNÇÃO, M.; APPANNABABU, S.; ALCANTARA-NUÑEZ, J.; LARA, A.L. de; SCARDUELLI, V.; GUIMARÃES, V.; LEPINE-SZILY, A.; SERRA, A.S.; LINARES, R.; ZAGATTO, V.A.B.; FARIA, P.N. de; MORCELLE, V.; MORAIS, M.C.; BARIONI, A.; SHORTO, J.M.B. . Spin-orbit effects in the 8Li+58Ni elastic scattering. Journal of Physics: Conference Series, v. 1291, n. 1, p. 1-5, 2019. DOI: 10.1088/1742-6596/1291/1/012030

    Abstract: In this work we present an elastic scattering angular distribution for the 8Li+58Ni system measured at Elab = 26.1 MeV. The 8Li beam was produced in the Radioactive Ion Beams in Brasil (RIBRAS) facility using the 7Li primary beam delivered by the 8-UD Pelletron accelerator. The angular distribution covers the angular range from 20 to 85 degrees in the center of mass frame. The data have been analysed by optical model and coupled channels calculations, including couplings to low-lying states in 8Li and the spin-orbit interaction. Our results indicate that the inclusion of the spin-orbit interaction in the calculations is important to describe the data at backward angles.

    Palavras-Chave: elastic scattering; lithium 8; nickel 58; beams; beams; angular distribution; l-s coupling; monte carlo method; simulation

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  • IPEN-DOC 26186

    ORMENIO, MATHEUS B. ; MAZIERO, JOANA da S. ; ROGERO, SIZUE O. ; ROGERO, JOSE R. . Resveratrol radiomodifier effect on Daphnia similis. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 867-872.

    Abstract: Resveratrol has beneficial properties as a potential antioxidant, protecting cells from free radicals, responsible for the natural aging process, anti-inflammatory action, acts against cardiovascular diseases in addition to showing a radiomodifying effect. Resveratrol is synthesized by a wide variety of plants in response to ultraviolet radiation or the action of certain pathogens. Due to the increasing use of this compound, due to its biological properties, studies are being carried out in the field of Ecotoxicology in order to provide information on the toxicity and radiomodifying effect of resveratrol for the development and adoption of criteria in order to improve environmental quality. It is known that resveratrol has radioprotective or radiosensitizing action, depending on its concentration. The objective of this study was to verify in which concentration resveratrol presents radioprotective effect. To achieve this goal, previous studies were carried out about the toxicity of resveratrol and gamma radiation effect on Daphnia similis to determine the lethal dose (LD50) of radiation and the EC50 (effective concentration) of resveratrol. Based on these data, the study of resveratrol radiomodifier effect on Daphnia similis demonstrated a higher resistance of this organism to gamma radiation at 55 Gy dose when previously exposed to resveratrol at concentrations of 6 and 7 μM, suggesting a radioprotective effect.

    Palavras-Chave: antioxidants; ecology; gamma radiation; microorganisms; polyphenols; radioprotective substances; toxicity

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  • IPEN-DOC 26185

    ISHIMARU, GABRIEL ; SANTOS, ELIANE C. dos ; SAIKI, MITIKO . Evaluation of the spatial variability of the elements in tree barks used as biomonitors of atmospheric pollution. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 856-866.

    Abstract: The tree barks have proven to be a valuable source of information on air quality and nowadays studies with this biomonitor are constantly being developed. However, data of several factors such as bark porosity, duration of the deposition on the bark and dispersion or variability of pollutants in a defined area that affect the accumulation of the pollutants in the barks are scarce in the literature. The aim of this study was to evaluate the spatial variability of chemical elements concentrations accumulated on Sibipiruna (Poincianella pluviosa) barks in order to examine their aerial dispersion in two small urban areas of the Metropolitan Region of São Paulo. The neutron activation analysis (NAA) applied in the analyses consisted of irradiation the aliquots of the sample together the synthetic element standards at the IEA-R1 nuclear reactor. Concentrations of the As, Br, Ca, Co, Cr, Cs, Fe, K, La, Mn, Rb, Sb, Sc, V and Zn were determined in tree barks using short and long irradiations. Results obtained in the analyses of the tree bark samples indicated that the variability of element concentrations depends on the element, study area and numbers of trees. The variability of element concentrations in general was higher for elements presenting low concentrations. Quality control of the analytical results was evaluated by the analysis of INCT-MPH-2 Mixed Polish Herbs Certified Reference Material and these results presented good accuracy with values of standardized difference or |ζ score| ≤ 2, indicating that the procedure of NAA applied is suitable for the analyses.

    Palavras-Chave: air pollution monitoring; bark; biological markers; concentration ratio; elements; neutron activation analysis; trees; brazil

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  • IPEN-DOC 26184

    SANTOS, ELIANE C. dos ; MAIHARA, VERA A. ; GENEZINI, FREDERICO A. ; SAIKI, MITIKO . A study on tree bark samples for atmospheric pollution monitoring. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 845-855.

    Abstract: Tree barks are considered a promising indicator of air pollution monitoring, because of its accumulation of aerosol particles, simplicity of species identification and wide geographical distribution. However, there are no established protocols for its sampling as well as there are no detailed studies on its usability as an alternative or complementary indicator of atmospheric pollution. In this study, barks from very common tree species, Sibipiruna (Poincianella pluviosa) and Tipuana (Tipuana tipu), were analyzed to define experimental conditions for their use as biomonitor of air pollution. Bark samples collected at the São Paulo city were cleaned and ground for analysis. Instrumental neutron activation analysis (INAA) was applied for the determination of As, Br, Ca, Co, Cr, Fe, K, Sb, Sc and Zn and graphite furnace atomic absorption spectrometry (GF AAS) for Cd and Pb. Results obtained in these analyses indicated that species of trees, bark surface layers taken for analysis as well as tree trunk diameter or tree age should be considered for use tree bark as a biomonitor. Analytical control of results carried out by analyzing certified reference materials demonstrated that INAA and GF AAS techniques can provide reliable data for element concentrations with standardized differences, |Enscore | < 1.

    Palavras-Chave: air pollution monitoring; bark; biological markers; detection; neutron activation analysis; pollutants; trees; sensitivity

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  • IPEN-DOC 26183

    COUTINHO, SUELLEN N. ; FIGUEIREDO, ANA MARIA G. ; QUINAGLIA, GILSON A; HELD, BARBARA. Accumulation of rare earth elements, U and Th in floating macrophytes from the Guarapiranga Reservoir. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 835-844.

    Abstract: Macrophytes play a relevant role in aquatic environments since they may accumulate metallic elements and can be an important tool for bioaccumulation studies, especially concerning an important and strategic water supply as Guarapiranga Reservoir. The reservoir is one of the main water supply systems in the São Paulo Metropolitan Region, contributing with 20% of the water provided to the region, which represents a water supply for about 3.7 million people. The industrial use of rare earth elements (REEs) has increased in the last years, affecting the levels of REEs in urban environments. Information about REEs accumulation in macrophytes of reservoirs are scarce, and none for Guarapiranga Reservoir. This study aims to evaluate REEs, U and Th concentration in floating macrophytes of Guarapiranga Reservoir, in order to assess possible sources and potential environmental impacts. Sampling was performed with the support of the Environmental Agency of the state of São Paulo (CETESB) in three points along the reservoir for dry (September 2016) and wet season (March and April 2016). Macrophyte samples were analyzed by Instrumental Neutron Activation Analysis (INAA) for REEs and Th and by Inductively Coupled Plasma Mass Spectrometry (ICP MS) for U. The results obtained were compared to Guarapiranga soil values and to other study using floating macrophytes, indicating a natural source of these elements in Guarapiranga Reservoir.

    Palavras-Chave: aquatic ecosystems; environmental impacts; icp mass spectroscopy; neutron activation analysis; plants; radioecological concentration; rare earths; thorium; uranium; brazil

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  • IPEN-DOC 26182

    CAVALCANTE, FERNANDA ; NISTI, MARCELO B. ; SAUEIA, CATIA H.R. . Estimation of exposure levels of terrestrial biota and radiation exposure around IPEN´s facilities. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 825-834.

    Abstract: Humans are exposed to natural radiation; soil is a major source of external and internal exposure of radiation. The external exposure from the soil is associated with gamma radiation and internal exposure mainly from radon inhalation. The aim of this study is to evaluate the exposure levels of terrestrial biota and to estimate the radiation exposure around IPEN facilities. The Institute comprises several nuclear and radioactive facilities including a research reactor, cyclotrons and a radioisotope and radiopharmaceutical production plant. The ERICA Tool was used to calculate the exposure levels of terrestrial biota; the estimation of radiation exposure for humans was determined using a model proposed by UNSCEAR (Absorbed dose rate in air and Annual effective dose equivalent) and Excess Lifetime Cancer Risk. Six soil points were collected and their activity concentrations were measured by gamma spectrometry, using a HPGe detector. Two soil points showed a risk coefficient greater than 1, suggesting that the screening dose ratio of 10μGy h 1 might be exceeding for the most exposed species, namely lichen and bryophytes, even though the activity concentration values of the analyzed radionuclides showed no evidence of soil contamination due to the atmospheric discharges of the IPEN facilities. Thus, the radioactive discharges in the soil from all facilities are negligible. Hence, the authors concluded that the ERICA Tool can be useful in assisting environmental radiological monitoring program for decision making, especially regarding: points collected, sample types and sampling frequency.

    Palavras-Chave: activity levels; bryophyta; environmental exposure pathway; gamma spectroscopy; high-purity ge detectors; human populations; ionizing radiations; lichens; soils; unscear

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  • IPEN-DOC 26181

    ARRUDA, CLAUDIA S.C. de ; FRANKLIN , ROBSON L.; FIGUEIREDO, ANA M.G. . Metal distribution in sediment cores of Ponte Nova Reservoir, São Paulo, Brazil. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 806-816.

    Abstract: The study of the metal distribution in sediments is very important from the point of view of environmental pollution. One of the objectives of the study of metal pollution in estuarine sediments is the historical record of anthropic activity. Ponte Nova reservoir, located in the upper basin of the Tietê River in the southern region of São Paulo State, covers an area of 25.7 km2 and drains an area of 320 km2. A sediment core was collected in the dam in August 2018 and in February 2019, sliced at every 2.5 cm, totalizing 13 samples in August and 17 samples in February 2019. Instrumental neutron activation analysis (INAA) was applied to the sediment samples to determine some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Tb, Th, U and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements. Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) was applied to determine (Cd, Cu, Mn, Ni, P and Pb). The results were evaluated by comparison to Canadian Sediment Quality Guidelines (TEL and PEL) and by the enrichment factor (EF) in relation to background values. EF>1.5 was obtained for As in both campaigns. In comparison to guidance values from Canada, Cr and Pb exceeded TEL in some superficial samples. Other elements analysed did not show enrichment factors >1.5 and the results were below TEL, indicating that there is not an important anthropogenic contribution of the analyzed elements in the reservoir.

    Palavras-Chave: contamination; mass spectroscopy; metals; neutron activation analysis; quality control; rare earths; sediments; trace amounts; water pollution; brazil

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  • IPEN-DOC 26180

    SILVA, GRAZIELA M. da ; PECEQUILO, BRIGITTE R.S. . Preliminary results of natural radioactivity in flours commercialized in the city São Paulo by high resolution gamma ray spectrometry. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 799-805.

    Abstract: In the present work, the activity concentrations of natural radionuclides 226Ra, 232Th and 40K were analyzed in 32 samples of wheat, corn, manioc and rice flours commonly used by residents of the city of São Paulo, Brazil. All samples were dried, homogenized and tightly sealed in standard 100 mL HDPE flasks with plan screw cap and bubble spigot and measured for 150 ks by gamma spectrometry with an Extended Range Coaxial germanium detector (Canberra GX4020 detector), after approximately 4 weeks storage, in order to ensure secular equilibrium. All spectra were analyzed with the InterWinner 6.0 software. The 226Ra activity concentration was determined from the weighted average concentrations of 214Pb and 214Bi. The 232Th activity concentration was determined from the weighted average concentrations of 228Ac, 212Pb and 212Bi and the 40K one from its single gamma transition. The 226Ra, 232Th and 40K activity concentrations results ranged, respectively, from 0.97 Bq/kg ± 0.42 Bq/kg to 4.75 Bq/kg ± 0.82 Bq/kg, from 8.07 Bq/kg ± 2.36 Bq/kg to 19.02 Bq/kg ± 3.56 Bq/kg and from 25.22 Bq/kg ± 4.38 Bq/kg to 153.5 Bq/kg ± 17.02 Bq/kg.

    Palavras-Chave: activity levels; brazil; flour; food; gamma spectroscopy; ge semiconductor detectors; natural radioactivity; radiation dose units; radioactivity; radioisotopes

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  • IPEN-DOC 26179

    SILVA, TATIANE B. de S.C. da ; OLIVEIRA, CINTIA C. de ; MARQUES, JOYCE R. ; FAUSTINO, MAINARA G. ; STELLATO, THAMIRIS B. ; MONTEIRO, LUCILENA R. ; PIRES, MARIA A.F. ; CONTRIM, MARYCEL E.B. . Estimated pollutant load from nuclear and energy research institute (IPEN/CNEN-SP, Brazil). In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 790-798.

    Abstract: Quantifying the pollutant load in a receiving water body is one of the needed steps to keep its original standards, irrespective of its releases source. Monitoring, and thus, controlling the amount of pollutants to be destined to the water body means ensuring water quality, keeping it free of excessive pollution and harm to human health and the environment. Hence, this paper aims to estimate the pollutant load of sanitary wastewater released by the Nuclear and Energy Research Institute (IPEN / CNEN-SP) during 2015 and 2016. The assay of Cd, Pb, Cu, Cr, Zn, Ba, Ni, Mn, Fe, B and Sn were performed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and As, Hg and Se by Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). The metals and total fixed solids pollutant load estimative carried out, employed wastewater flow measurement, using bromide (Br- ) as tracer and the annual water consumption at IPEN. This evaluation is performed annually by IPEN since 2006 as part of the Environmental Monitoring Program (PMA-Q), in order to comply with the current environmental legislation and the Term of Adjustment of Conduct requirements, agreed with the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA).

    Palavras-Chave: absorption spectroscopy; brazilian cnen; environment; flow rate; metals; pollutants; semimetals; solids; waste water

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  • IPEN-DOC 26178

    RODRIGUES, ELAINE A. ; AQUINO, AFONSO R. de ; CARVALHO, AMANDA R. de. Convergence between studies on ecosystem services and nuclear technology: a necessary approximation. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 774-789.

    Abstract: If in the 19th-century scientific knowledge moved from a generalist perspective to a growing specialization, in recent decades, problems that transcend disciplinary and political boundaries have required solutions based on interdisciplinary research and global actions, which led to the establishment of the Sustainable Development Goals (SDGs) in 2015. In the same perspective, studies on ecosystem services emerged as an area of transdisciplinary knowledge in rapid growth, while advances in the nuclear field enabled applications in industry, health, agriculture and the environment. Considering the development of these two spheres of knowledge, the objective of this study is to evaluate the correlation between the areas of Ecosystem Services and Nuclear Science and Technology, through category building and content analysis applied to articles listed in the Web of Science. From 1980 to June 2019, 22,751 records (article and review) were listed for the term "ecosystem service*". When refining the result with the application of descriptors related to the nuclear area, correspondences were found for "Uranium"=13; "Nuclear Power"=6; "Nuclear Energy"=1; "Nuclear technolog*"=1; "Nuclear fuel*"=1; "Nuclear material*"=1, in a total of 23 correspondences only. On the other hand, the search using key descriptors of the nuclear area, plus the terms "nature" or "ecosystem*" or "environment" for the same period, totaled 9,328 papers (articles and reviews). While the NST is broadly convergent with SE, this correlation needs to be made more explicit in the studies, expanding the prospects for the conservation, preservation and recovery of the ecosystem services and their contribution to human wellbeing.

    Palavras-Chave: data; ecology; ecosystems; environment; information; information retrieval; information systems; nuclear energy

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  • IPEN-DOC 26523

    REGO, ULISSES A. do; LOPES, THIAGO ; BOTT-NETO, JOSE L.; TANAKA, AURO A.; TICIANELLI, EDSON A.. Oxygen reduction electrocatalysis on transition metal-nitrogen modified tungsten carbide nanomaterials. Journal of Electroanalytical Chemistry, v. 810, p. 222-231, 2018. DOI: 10.1016/j.jelechem.2018.01.013

    Abstract: Considering the technological importance of the oxygen reduction reaction (ORR) and the cost constraints of highly catalytically active precious metals, recent research efforts have been focused on designing and synthesizing earth abundant non-precious metal catalysts for this reaction. Among recent advances in this area, transition metal-nitrogen modified tungsten carbides can be pointed as prominent candidates as ORR electrocatalysts. Nevertheless, mechanistically understandings of which active sites are responsible for the ORR electrocatalysis on these materials are required for the rational design of suitable materials. In the present work, various tungsten carbides and iron-nitrogen modified tungsten carbides catalysts are synthesized and in-depth characterized through various physical and electrochemical techniques towards gaining insights on the ORR process on these materials in both acidic and alkaline media. High performance materials are developed, with the most active presenting only a ca. 0.060 V increase in the ORR overpotential, compared to a standard platinum catalyst in an alkaline medium. The in-depth analyses allowed for suggestions on reaction pathways for the oxygen reduction on the hybrid Fe/N/WC/C nanomaterials in terms of active sites. These finds might direct further developments in the research on transition metal-nitrogen modified tungsten carbide materials.

    Palavras-Chave: electrochemical corrosion; oxygen; reduction; carbides; catalysts; transition elements; electrochemistry; energy storage; storage; electrolytes

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  • IPEN-DOC 26522

    COCATO, MARIA L. ; LOBO, ALEXANDRE R.; AZEVEDO-MARTINS, ANNA K.; MANCINI FILHO, JORGE; SA, LILIAN R.M. de; COLLI, CELIA. Effects of a moderate iron overload and its interaction with yacon flour, and/or phytate, in the diet on liver antioxidant enzymes and hepatocyte apoptosis in rats. Food Chemistry, v. 285, p. 171-179, 2019. DOI: 10.1016/j.foodchem.2019.01.142

    Abstract: The effect of moderate Fe overload in the diet and its interaction with phytate, and/or yacon flour (YF), recognized as an inhibitor, and facilitator, of Fe absorption, respectively, was evaluated in healthy rats. For this purpose the following parameters were analyzed: (1) apparent iron (Fe), copper (Cu) and zinc (Zn) absorption; (2) blood Fe; (3) blood lipids (cholesterol, tryacylglicerol); (4) blood AST and ALT; (5) liver histology (histopathology, hemosiderin depots, apoptosis index; (6) liver fatty acid incorporation; (7) liver antioxidant enzyme activity. Moderate Fe overload may cause change in some liver markers (hemosiderin depots, apoptosis index and GPx) and blood lipids (total cholesterol and VLDL) and the interaction with yacon flour, and phytate, in the Fe overloaded diets may exert a protective effect on these alterations.

    Palavras-Chave: iron compounds; iron sulfates; phytic acid; roots; oligosaccharides; plants; solanum tuberosum; liver; blood cells; blood; chemical analysis; blood serum; nutrition; lipoproteins; absorption; antioxidants; enzymes; copper; zinc

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  • IPEN-DOC 26515

    BUSTILLOS, OSCAR V. . O analisador eletromagnético de íons na espectrometria de massas. Revista Analytica, v. 17, n. 101, p. 26-27, 2019.

    Palavras-Chave: ions; electromagnetic interactions; ion emission; mass spectroscopy; ionization; electric fields

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  • IPEN-DOC 26507

    BUSTILLOS, OSCAR V. . Analisadores de íons por quadrupolo na espectrometria de massas. Revista Analytica, v. 17, n. 102, p. 32-34, 2019.

    Palavras-Chave: quadrupoles; mass spectroscopy; ions; ionization; faraday effect

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  • IPEN-DOC 26503

    BUSTILLOS, OSCAR V. . O detector de íons na espectrometria de massas. Revista Analytica, v. 17, n. 103, p. 31-32, 2019.

    Palavras-Chave: mass spectroscopy; ion detection; faraday effect; electron multipliers; electron multiplier detectors; magnetic analyzers

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  • IPEN-DOC 26463

    SILVA, ISRAEL G.F. da; ANDRADE, ARNALDO H.P. de ; MONTEIRO, WALDEMAR A. . Leak-Before-Break methodology applied to different piping materials: a performance evaluation. Frattura ed Integrità Strutturale, v. 13, n. 50, p. 46-53, 2019. DOI: 10.3221/IGF-ESIS.50.06

    Abstract: This paper presents a study of the application of Leak-Before- Break (LBB) to nuclear piping using three different materials. Although had been introduced more than three decades ago, through a fundamentally technical justification, the LBB concept currently has been widely applied in nuclear installations projects in several countries. Based on the fracture mechanics, the LBB concept considers that a leakage from a crack can be detected before it reaches a critical size that implies the pipe failure, that is, the LBB analysis demonstrates through a technical justification that the probability of pipe rupture is extremely low. Among the aspects that involve the application of LBB, the main ones are: the definition of the material properties, which are obtained through tensile and fracture tests; the leakage analysis, which determines the rate of leakage due to the presence of a through-wall crack; and the analysis that verifies if the crack is stable considering the failure modes by ductile tear and plastic collapse. The materials SA-508 Cl. 3, SA-106 Gr. B and SA-376-TP304 were evaluated in relation to their performances for LBB. Data obtained from literature cases were used for the materials properties, and for the geometry and loadings of the pipe, all corresponding to the primary circuit of a PWR reactor. After application of the LBB, it was verified that all three materials met the limits established in the methodology. SA-508 Cl. 3 and SA-376-TP304 steels showed the best performance for ductile tear failure and plastic collapse failure, respectively, and SA-106 Gr. B steel had the lowest performance in both. All three materials presented plastic collapse as the most likely failure mode. In general, SA-376-TP304 steel presented the best performance for the LBB among the three materials evaluated in this work.

    Palavras-Chave: leaks; pipes; performance; materials; pwr type reactors; fracture mechanics; fracture properties; steels; carbon steels; stainless steel-304; stainless steels

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  • IPEN-DOC 26177

    GONÇALVES, PEDRO do N. ; DAMATTO, SANDRA R. ; LEONARDO, LUCIO ; SOUZA, JOSEILTON M. de . Natural radionuclides in soil profiles and sediment cores from Jundiai reservoir, state of São Paulo. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 751-763.

    Abstract: The activity concentration of natural radionuclides in soils and sediments is dependent on many factors, such as the rock parental material, pedogenic and weathering processes, physical and chemical properties of the environment, anthropogenic sources, among other aspects. Naturally occurring radiation in the environment is mostly due to the decay of 238U and 232Th series; another important source of natural radiation is the radionuclide 40K. Reservoirs are artificial systems made in order to stock riverine and rainwater to supply water to the population. There are few studies about the levels of natural radionuclides in reservoirs in both, international and national, literature. The objective of this paper was to evaluate the activity concentration of 238U and 232Th by Instrumental Neutron Activation Analysis and 226Ra, 210Pb, 228Ra, 228Th and 40K by gamma spectrometry in two soil profiles and three sediment cores collected in the catchment area of Jundiai reservoir, located in the state of São Paulo, Brazil. Principal component analysis was applied to verify the correlation of the activity concentrations of the natural radionuclides with physical and chemical properties of soil and sediment samples. In the soil profiles, the radionuclides that showed higher activity concentration when compared to the UNSCEAR values were 232Th in the both profiles and 238U only in one; for the sediment cores, the activity concentrations of 238U and 232Th were higher than the UNSCEAR values in all the samples analyzed and also for the radionuclide 226Ra in two sediment cores.

    Palavras-Chave: chemical properties; natural radioactivity; neutron activation analysis; physical properties; radioecological concentration; sediments; soils; thorium 232; uranium 238; water reservoirs

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  • IPEN-DOC 26434

    LEVY, DENISE ; VILLAVICENCIO, ANNA L.C.H. . Educating the educators: interdisciplinary approaches to enhance science teaching. World Academy of Science, Engineering and Technology: International Journal of Educational and Pedagogical Sciences, v. 13, n. 9, p. 1206-1209, 2019. DOI: 10.5281/zenodo.3461956

    Abstract: In a rapid-changing world, science teachers face considerable challenges. In addition to the basic curriculum, there must be included several transversal themes, which demand creative and innovative strategies to be arranged and integrated to traditional disciplines. In Brazil, nuclear science is still a controversial theme, and teachers themselves seem to be unaware of the issue, most often perpetuating prejudice, errors and misconceptions. This article presents the authors’ experience in the development of an interdisciplinary pedagogical proposal to include nuclear science in the basic curriculum, in a transversal and integrating way. The methodology applied was based on the analysis of several normative documents that define the requirements of essential learning, competences and skills of basic education for all schools in Brazil. The didactic materials and resources were developed according to the best practices to improve learning processes privileging constructivist educational techniques, with emphasis on active learning process, collaborative learning and learning through research. The material consists of an illustrated book for students, a book for teachers and a manual with activities that can articulate nuclear science to different disciplines: Portuguese, mathematics, science, art, English, history and geography. The content counts on high scientific rigor and articulate nuclear technology with topics of interest to society in the most diverse spheres, such as food supply, public health, food safety and foreign trade. Moreover, this pedagogical proposal takes advantage of the potential value of digital technologies, implementing QR codes that excite and challenge students of all ages, improving interaction and engagement. The expected results include the education of the educators for nuclear science communication in a transversal and integrating way, demystifying nuclear technology in a contextualized and significant approach. It is expected that the interdisciplinary pedagogical proposal contributes to improving attitudes towards knowledge construction, privileging reconstructive questioning, fostering a culture of systematic curiosity and encouraging critical thinking skills.

    Palavras-Chave: education; nuclear energy; learning; training; educational tools; information dissemination; nuclear power

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  • IPEN-DOC 26176

    MELO, CAMILA G. ; ROSA, JORGE M. ; GARCIA, VANESSA S.G. ; BORRELY, SUELI I. ; PEREIRA, MARIA da C.C. . Toxicity and color reduction of reactive dyestuff RB21 and surfactant submitted to electron beam irradiation. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 743-750.

    Abstract: There is an unwelcome reaction between the coloring and the water during the dyeing procedure, a portion of the coloring agent is lost in the bathing and it will compose the final whole effluent. The high absorbance index is related to lost dyes and they also contribute with the toxic effects to the aquatic biota. In addition, these effluents contain large quantity of surfactants applied during dyeing baths, which also contribute to the high toxicity in these samples. The objective of this study was to evaluate electron beam irradiation technology, applied in samples of the Color Index Reactive Blue 21 (RB21) dye and in samples of surfactant nonionic and in order to reduce toxicity for both and for RB21, color reduction. Among the objectives of the study there are the dye exhaustion degree, and some physic-chemical parameters. The acute toxicity assays were carried with Daphnia similis microcrustacean and the results for of dyestuff solution were: the irradiated samples with concentration of 0.61g.L-1 did not present significant results, the EC 50(%) value was to 58.26 for irradiated sample with 2.5kGy and EC 50(%) 63.59 for sample irradiated with 5kGy. The surfactant was more toxic than RB 21, with EC 50(%) value at 0.42. The color reduction reached 63.30% for the sample of the lowest concentration of effluent. There was a reduction of pH during irradiation.

    Palavras-Chave: color; dyes; electron beams; irradiation; liquid wastes; ph value; reduction; surfactants; toxicity; water

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  • IPEN-DOC 22303

    RIELLA, HUMBERTO . Da pesquisa básica à produção. Brasil Nuclear, v. 25, n. 49, p. 33-33, 2018.

    Observação: Depoimento

    Palavras-Chave: nuclear fuells; fuel cycle centers; fuel fabrication plants; uranium dioxide; fuel plates; scientific personnel

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  • IPEN-DOC 26175

    GARCIA, VANESSA S.G. ; BOIANI, NATHALIA F. ; ROSA, JORGE M ; BORRELY, SUELI I. . Toxicity of textile effluents treated by electron beam technology. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 735-742.

    Abstract: The textile industry uses expressive amount of water during the production and generate effluents that contain residuals of dyes, surfactants, peroxides, acids and salts, and toxicity. In addition, the textile effluents are commonly colored, because the dyes used in fibers dyeing usually have low fixation and high solubility. Many of the mentioned products are not easily removed, requiring additional treatment steps. Advanced Oxidative Processes, such as electron beam irradiantion (EBI), can be a good alternative to reduction of organic pollutants from effluents. Therefore, studies on these contaminants in aquatic environment are important for assessing their impacts on ecosystems and water quality. The objective of this study was to evaluate the toxicity of textile effluents treated with EBI. The doses of 2.5 kGy and 5.0 kGy were used. The toxicity assays were performed with Daphnia similis organisms, exposed to samples during 48 hours, and the results expressed by EC50 (median effective concentration). For the textile effluent, EC 50% values ranged from: 2.95 ±0.13 (raw effluent) until 20.90 ±1.48 (irradiated effluent, at 5kGy). The EBI treatment was effective for toxicity reduction, with efficiency higher than 60% (2.5 kGy) and 80% (5.0 kGy). The study of organic and inorganic contaminants, presents in these effluents, demonstred EC 50 values below 5%. These results demonstrate high toxicity of contaminants from textile effluents for aquatic organisms (D. similis, cladocera). Similar data was observed for the raw effluent. These values are relevant for thinking radiation as a possible technology for such a type of effluent.

    Palavras-Chave: chemical effluents; decontamination; electron beams; environment; industrial wastes; irradiation; liquid wastes; pollutants; textile industry; textiles; toxicity; water quality

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  • IPEN-DOC 26174

    FEREIRA, ADEMAR DE OLIVEIRA; PECEQUILO, BRIGITTE R.S. . Dose rates evaluation of some granitic rocks from the Paraná state. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 723-729.

    Abstract: Granitic rocks, widely used as building materials, are known to contain natural radionuclides and can be an important source of radiation for the population. Thirty-four samples of granite rocks from geological occurrences in Paraná state were measured with an HPGe detector for evaluation of226Ra, 232Th and 40K activity concentrations. The effective annual external dose was evaluated from these radionuclides activities using a dosimetric room model with dimensions 4 m x 5 m x 2.8 m in which all walls are internally coated with granites of thickness 2 cm and considering an annual exposure time of 7000 h. This value was suggested by the European Commission on Radiological Protection for superficial coating materials. The internal exposure was evaluated from radon air concentration of the model room, simulated from an exhalation rate of 222Rn, determined with CR-39 solid state nuclear track detectors using the sealed can technique, considering a ventilation rate of 0.5 h-1 and an annual exposure time of 7000 h. The results of this study showed that the increase in the annual effective dose ranged from 62 ± 3 μSv.a-1 to 138 ± 1 μSv.a-1 from external gamma rays and the increase in the annual effective dose ranged from 0.39 ± 0.04 μSv.a-1 to 70 ± 4 μSv.a-1 from radon inhalation. All results stayed below 1 mSv.a-1 recommended by the European Commission on Radiological Protection.

    Palavras-Chave: building materials; environmental effects; high-purity ge detectors; inhalation; potassium 40; radiation doses; radiation protection; radium 226; radon 222; thorium 232

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  • IPEN-DOC 26173

    CAMARGO, GUSTAVO E.; FERREIRA, ADEMAR O.; NERY, ANDRESSA D. ; SAUEIA, CATIA R. ; NISTI, MARCELO B. . Determination of gross alpha and beta radioactivity by liquid scintillation counting in drinking water consumed in the cities of Paraná-Brazil. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 710-715.

    Abstract: The liquid scintillation counting (LSC) is a technique in which the sample is mixed to a chemical organic liquid, forming a scintillation solution, capable to convert the kinetic energy of nuclear emissions into light energy photons. The aim of this study was to quantify the concentration of gross alpha and beta radioactivity in drinking water using the LSC. The water samples were collected in the Paraná cities: Telêmaco Borba, Castro, Tibagi, Reserva, Curiúva, Ponta Grossa, Imbaú and Curitiba. They have free access sources of drinking water to the public. The initial step of the methodology was standardizing the pre-concentration of the water samples by heating on a hot plate from 1 L to a final volume of 50 mL, at maximum temperature of 80°C. An aliquot of 5 mL of the final solution was mixed with 15 mL of the scintillation solution (Hisafe 3) in a vial and measured on a LSC. The equipment used for the measurement of gross alpha and beta activities was a 1220 Quantulus™ Ultra Low Level Liquid Scintillation Spectrometer. The activity concentration of gross alpha varied from <0.10 to 0.20 Bq L-1 and gross beta varied from <0.18 to 0.23 Bq L-1. The results of gross alpha and beta concentration obtained in the samples are below the maximum limits adopted by Ministry of Health in Brazil.

    Palavras-Chave: alpha decay radioisotopes; beta decay radioisotopes; brazil; contamination; drinking water; ecosystems; radiation dose ranges; radioactivity; radioecological concentration; scintillation counting

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  • IPEN-DOC 26526

    CABRAL, EDUARDO L.L. ; LEE, SEUNG MIN ; LIMA, JOSE R. de . Fusão nuclear com confinamento eletrostático assistido por campo magnético – projeto mecânico e elétrico. São Paulo: iInstituto de Pesquisas Energéticas e Nucleares - CEENG, Setembro, 2019. (IPEN-CEN-P&D-CEN-039-00-RELT-001-00). Restrito.

    Título do projeto: Reator de Fusão Nuclear com Confinamento Eletrostático Assistido por Campo Magnético

    Palavras-Chave: thermonuclear reactions; electrostatic analyzers; design; specifications; magnetic fields; solenoids; cooling systems; electric coils; magnetic circuits

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  • IPEN-DOC 26525

    LANDIM, HUGO R. . Operação do Reator IPEN/MB-01 – Ano 2018 : Ano 2018. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - SEORI, Fevereiro, 2019. (IPEN-CEN-INF-CENR-089-00-RELT-001-00). Restrito.

    Título do projeto: Operação do Reator IPEN/MB-01

    Abstract: Este relatório tem o objetivo de apresentar as atividades de operação realizadas no Reator IPEN/MB-01 durante o ano de 2018. O Reator IPEN/MB-01 é uma instalação nuclear que permite a simulação de todas as características nucleares de um reator de grande porte em escala reduzida, sem que haja a necessidade de construir-se um complexo sistema de remoção de calor. Esse tipo de reator é conhecido mundialmente como reator de potência zero ou Unidade Crítica, sendo no nosso caso, projetado para operar a uma potência máxima de 100 watts. Esses reatores representam uma ferramenta básica, que permitem aos pesquisadores estudar não apenas por cálculos teóricos, mas também com medidas experimentais, o desempenho e as características do núcleo de um reator de potência ou de propulsão naval, antes da sua efetiva instalação, simulando as condições de projeto na própria instalação.

    Palavras-Chave: ipen-mb-1 reactor; operations research; reactor operation; reactor operators; experiment results; training reactors; research and test reactors

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  • IPEN-DOC 26520

    GONZALES-LORENZO, CARLOS D.; GUNDU RAO, T.K.; CANO, NILO F.; CARRERA, BETZABEL N.S. ; ROCCAB, RENE R.; CUEVAS-ARIZACA, EDY E.; AYALA-ARENAS, JORGE S.; WATANABE, SHIGUEO . Thermoluminescence and defect centers in β-CaSiO3 polycrystal. Journal of Luminescence, v. 217, p. 1-7, 2020. DOI: 10.1016/j.jlumin.2019.116783

    Abstract: β: CaSiO3 polycrystal was synthesized by the devitrification method. The polycrystal exhibits three thermoluminescence (TL) peaks at 124 ºC, 250 ºC and 306 ºC. Electron paramagnetic resonance (EPR) spectroscopy was used to study the defect centers induced in the polycrystal by gamma irradiation and to identify the centers responsible for the TL process. Three defect centers contribute to the observed spectrum at room temperature. Center I with principal g-values 2.0135, 2.0094 and 2.0038 is attributed to O ion and the center appears to be the recombination center for 124 ºC, 147 ºC and 306 C TL peaks. Center II exhibiting an isotropic g-value of 2.00025 is identified as an Fþ-center (singly ionized oxygen vacancy). Fþ-center is also observed to be a recombination center for several TL peaks. Center III is assigned to a Ti3þcenter displaying an orthorhombic g- tensor with principal values g1 ¼1.9830, g2 ¼1.9741 and g3 ¼1.9046. This center is associated with 124 ºC and 147 ºC TL peaks. TL emission spectrum of β-CaSiO3 shows two emission bands at 370 and 520 nm.

    Palavras-Chave: polycrystals; calcium oxides; calcium silicates; silicon oxides; crystal defects; thermoluminescence; epr spectrometers; electron spin resonance

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  • IPEN-DOC 26450

    BARDELLA, FERNANDO ; RODRIGUES, ANDRE M. ; LEAL NETO, RICARDO M. . The use of crystallographic software as educational support to materials science and engineering. Journal of Materials Education, v. 40, n. 3-4, p. 79-106, 2018.

    Abstract: Justified by the lack of proper didatic tools, a systematic review process was executed to verify at what extent existing crystallographic software can support the teaching process and the understanding of crystal structures in materials science and engineering disciplines. A revision protocol was established and executed, where 26 references were selected and analyzed from a total of 804 software from the International Union of Crystallography (IUCr) software database. The research questions were deemed properly answered by this revision, where both a group of top performers (Class A) and gaps not fulfilled by any software, revealed enhancement possibilities and opportunities for development of new software focused on the educational support to materials science and engineering curricula.

    Palavras-Chave: education; crystallography; data processing; computer codes; engineering; educational tools; training

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  • IPEN-DOC 26524

    LANDIM, HUGO R. . Operação do Reator IPEN/MB-01 – Ano 2012. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - SEORI, Fevereiro, 2019. (IPEN-CEN-INF-CENR-067-00-RELT-001-00). Restrito.

    Título do projeto: Operação do Reator IPEN/MB-01

    Abstract: Este relatório tem o objetivo de apresentar as atividades de operação realizadas no Reator IPEN/MB-01 durante o ano de 2012. O Reator IPEN/MB-01 é uma instalação nuclear que permite a simulação de todas as características nucleares de um reator de grande porte em escala reduzida, sem que haja a necessidade de construir-se um complexo sistema de remoção de calor. Esse tipo de reator é conhecido mundialmente como reator de potência zero ou Unidade Crítica, sendo no nosso caso, projetado para operar a uma potência máxima de 100 watts. Esses reatores representam uma ferramenta básica, que permitem aos pesquisadores estudar não apenas por cálculos teóricos, mas também com medidas experimentais, o desempenho e as características do núcleo de um reator de potência ou de propulsão naval, antes da sua efetiva instalação, simulando as condições de projeto na própria instalação.

    Palavras-Chave: ipen-mb-1 reactor; operations research; reactor operation; reactor operators; experiment results; training reactors; research and test reactors

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  • IPEN-DOC 26448

    ARAUJO, JESUINA C.S.; OTON, LAIS F.; BESSA, BRUNO; NETO, ANTONIO B.S.; OLIVEIRA, ALCINEIA C.; LANG, ROSSANO; OTUBO, LARISSA ; BUENO, JOSE M.C.. The role of Pt loading on La2O3-Al2O3 support for methane conversion reactions via partial oxidation and steam reforming. Fuel, v. 254, p. 1-15, 2019. DOI: 10.1016/j.fuel.2019.115681

    Abstract: The effects of Pt loadings on the catalytic performance of the La2O3-Al2O3-supported Pt nanoparticles are investigated during the partial oxidation (POM) and steam reforming of methane (SRM). From analyses of XRD, UV–Vis, TPR, CO-DRIFTS, XPS, Raman spectroscopy, cyclohexane dehydrogenation reaction, Pt surface species and their dispersions were dully observed. The good degrees of interaction between Pt nanoparticles and lanthana species in the support gave robust catalysts in POM, evidenced by XPS and TEM for low Pt loadings. Arrhenius plots for SRM showed an apparent activation energy of 70 kJ mol−1 for all Pt(x wt%)/Al2O3-La2O3 catalysts. An enrichment of the Pt species at loadings superior to 0.5 wt% resulted in Pt nanoparticles weakly interacting with the La2O3-Al2O3 support and the consequent sintering of the particles in SRM and POM reactions. On the contrary, best catalytic results and a more stable performance during POM in 24 h on stream was observed, when dispersing a 0.5 wt% of Pt on the support. A strong interaction between the PtOx species and the support was crucial for La2O3 preserve the high dispersion of the Pt entities. This favored the reactivity of surface oxygen species coming from LaPtOx[Pto]n. Indeed, this chemical entity was located on the surface of the solid, at the periphery of Pto particles, being further converted into La2PtOx[Pto]n−1. The decomposition of CH4 to CO and H2 as well as the coke gasification on the accessible Pt sites gave better conversions for Pt(0.5 wt%)/Al2O3- La2O3 compared with the other solids with higher Pt loadings.

    Palavras-Chave: nanoparticles; surfaces; particles; lanthanum oxides; catalysts; aluminium oxides; oxidation; steam reformer processes

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  • IPEN-DOC 26172

    SILVA, THALITA T. ; BORRELY, SUELI I. . Use of ionizing radiation for the inhibition and removal of cyanotoxins in the water: a review. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 690-699.

    Abstract: Cyanobacteria blooms have been observed in the aquatic systems in different continents, frequently with the production of cyanotoxins that negatively alter water potability. This work provides a small review of the state of the art of the use of advanced oxidation processes in the degradation of cyanobacteria and their toxins. It is divided into 3 major sections: the first part focuses on cyanobacteria and the mechanisms of production related to the environmental conditions. The second part we exposed the guidance values of the evaluation in drinking water for the control of cyanotoxins worldwide, and Brazil regulations. In the third and last part, we present some studies about the use of the advanced oxidation processes for the inhibition and degradation of cyanotoxins, focuses on ionizing radiation: gamma-ray and electron beam irradiation. In conclusion, the ionizing radiation is an efficient and economically viable alternative on the remediation of areas contaminated by cyanobacteria blooms and their toxins, mainly in the reservoirs destined to the water treatment and supply. As well, some suggestions are provided for additional studies about the use of this technology for the treatment of drinking water.

    Palavras-Chave: algae; bacteria; comparative evaluations; drinking water; ecosystems; environmental effects; gamma radiation; ionizing radiations; radiation doses; toxicity; toxins

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  • IPEN-DOC 26500

    SILVA, ISRAEL G.F. da . Avaliação do desempenho de diferentes materiais de tubulação para aplicação do Leak-Before-Break (LBB) / Performance evaluation of different piping materials for application of Leak-Before-Break (LBB) . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 65 p. Orientador: Waldemar Alfredo Monteiro. DOI: 10.11606/D.85.2019.tde-03072019-152331

    Abstract: Fundamentado na mecânica da fratura, o conceito do Leak-Before-Break (LBB) "Vazamento Antes da Falha" considera que um vazamento proveniente de uma trinca pode ser detectado antes de alcançar um tamanho crítico que implique na falha da tubulação, ou seja, a análise do LBB demostra através de uma justificativa técnica que a probabilidade de ruptura da tubulação é extremamente baixa. Dentre os aspectos que envolvem a aplicação do LBB, os principais são: a definição das propriedades do material, que são extraídos através de ensaios à tração e à fratura; a análise do vazamento, que determina a taxa de vazamento devido à presença de uma trinca passante; e a análise que verifica se a trinca é estável considerando os modos de falha por rasgamento dúctil e por colapso plástico. Os materiais SA-508 Cl. 3, SA-106 Gr. B e SA-376-TP304 foram avaliados quanto aos seus desempenhos para o LBB. Utilizaram-se dados extraídos de casos da literatura para as propriedades dos materiais, e para a geometria e carregamentos da tubulação, todos correspondentes ao circuito primário de um reator PWR. Após aplicação do LBB, constatou-se que todos os três materiais atenderam os limites do estabelecidos na metodologia. Verificou-se que os materiais SA-508 Cl. 3 e SA-376-TP304 mostraram o melhor desempenho para falha por rasgamento dúctil e falha por colapso plástico, respectivamente, e o material SA-106 Gr. B teve o menor desempenho em ambos. Todos os três materiais apresentaram o colapso plástico como modo de falha mais provável. De uma forma generalizada, o material SA-376-TP304 obteve o melhor desempenho para o LBB dentre os três materiais avaliados neste trabalho.

    Palavras-Chave: safety engineering; reactor safety; pressure vessels; pipes; radioactivity transport; gases; oils; reactor control systems

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  • IPEN-DOC 26496

    RIBEIRO JUNIOR, IBERE S. . Uso de sistema de coincidência gama-gama associado à espectroscopia simples em medidas de análise por ativação neutrônica / Use of gamma-gamma coincidence system associated to simple spectroscopy in neutron activation analysis measurements . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 152 p. Orientador: Frederico Antonio Genezini. DOI: 10.11606/T.85.2019.tde-22072019-080949

    Abstract: Nesse trabalho foi desenvolvido um sistema de aquisição γγ que possibilita realizar medidas de Análise por Ativação Neutrônica Instrumental por espectroscopia gama unidimensional e em coincidência simultaneamente para os elementos As, Co, Cs, La, Sc, Se e Sm. Para tal foram realizadas medidas preliminares em sistemas de aquisição γγ baseados em instrumentação analógica e digital a fim de se verificar a eficiência da técnica a partir de medições de padrões sintéticos e análises de materiais de referência certificados. Essas medidas também auxiliaram na escolha do tipo de instrumentação mais apropriada para o desenvolvimento do sistema de aquisição no Laboratório de Física Nuclear Aplicada (LFNA) do IPEN. O sistema montado no LFNA é composto de uma placa digitalizadora da marca CAEN modelo v1724 e dois detectores de germânio hiperpuro. A aquisição dos dados é controlada pelo software MC2Analyzer, que fornece dados brutos de energia e tempo dos pulsos registrados. Foram desenvolvidos dois programas de redução de dados que selecionam os eventos em coincidência a partir dos espectros unidimensionais: o DPP que prepara os dados para serem analisados em programas de análise de espectros bidimensionais; e o AnalisaCaen que trata os dados para sejam analisados em programas de análises de espectros unidimensionais. Foram realizadas análises de materiais de referência certificados biológicos e geológicos, e também padrões sintéticos utilizando-se as técnicas de Análise por Ativação Neutrônica convencional e em coincidência. Os resultados permitiram verificar a confiabilidade dos valores das concentrações dos elementos As, Co, Cs, La, Sc, Se e Sm obtidos com o sistema de coincidência desenvolvido. Os resultados obtidos por ambas as técnicas, Análise por Ativação Neutrônica Convencional e Análise por Ativação Neutrônica em Coincidência, foram comparados e valiados em termos de precisão e exatidão pelo critério de Enscore. Em alguns casos, os resultados de concentração obtidos por meio das medidas de coincidência forneceram melhores do que os resultados obtidos pela espectroscopia gama convencional.

    Palavras-Chave: neutron activation analysis; coincidence spectrometry; coincidence methods; radiation detection; gamma-gamma logging; measure theory; perturbed angular correlation; compton effect; bremsstrahlung; limiter circuits; data acquisition systems; data transmission; digital systems

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  • IPEN-DOC 26492

    PEREIRA JUNIOR, JEDAIAS T. . Desenvolvimento de processos de ablação dos polímeros poliestireno e polidimetilsiloxano com lasers de pulsos ultracurtos / Development of ablation processes of polystyrene and polydimethylsiloxane polymers with ultrashort pulse laser . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 95 p. Orientador: Wagner de Rossi. DOI: 10.11606/D.85.2019.tde-22072019-074048

    Abstract: Através da aplicação de microusinagem com laser de femtossegundos é possível fazer ablação de cavidades com precisão de poucos μm. Se comparado com o processo de litografia, por exemplo, apresenta algumas vantagens como poder ser aplicada em praticamente qualquer tipo de substrato e utilizar tecnologia simples de usinagem assistida por computador para a geração de perfis de duas ou três dimensões. O objetivo deste trabalho foi estudar estratégias e parâmetros com laser de femtossegundos para ablação dos polímeros poliestireno e polidimetilsiloxano (PDMS), de forma a afetar o mínimo possível as características das regiões adjacentes à usinagem. Como exemplos de aplicações, temos o primeiro material que tem sido texturizado para cultura controlada de células do coração e o segundo que faz parte da estrutura de certos circuitos microfluídicos. A fim de se fazer um levantamento dos limiares de ablação destes materiais, foram utilizadas as técnicas D-Scan e regressão de diâmetro. Diversos traços foram realizados variando-se as velocidades de deslocamento da amostra. Com isso, foram analisados os efeitos de incubação e a relação da sobreposição de pulsos com a largura dos traços criados. Por fim foram incluídos incrementos laterais entre os traços, obtendo-se uma área ablacionada. Procurou-se variar a frequência dos pulsos nos experimentos para investigar o aparecimento de um possível efeito térmico com diferentes intervalos de tempo entre pulsos consecutivos. Foram conseguidos parâmetros em que é possível realizar a ablação de pontos, traços e superfícies sem aparente fusão do material. Porém observou-se que o aspecto do perfil ablacionado não tem a tendência de ficar liso e uniforme. Os resultados demonstram a enorme variedade de combinações e parâmetros que podem ser obtidos com a técnica de microusinagem com laser de femtossegundos e favorecem o estudo do processamento destes polímeros.

    Palavras-Chave: polystyrene; organic silicon compounds; organic polymers; ablation; microstructure; machine tools; electromagnetic pulses; amplification; lasers; scanning electron microscopy; process development units

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  • IPEN-DOC 26491

    MACHI, ANDRE R. . Efeitos da radiação ionizante nas fases do ciclo evolutivo de Aedes aegypti L. visando o seu controle através da técnica do inseto estéril / Ionizing radiation effects on stages of evolution cicle of Aedes aegypti L. aiming the control across of the insect sterile technique . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 75 p. Orientador: Valter Arthur. DOI: 10.11606/T.85.2019.tde-20052019-085251

    Abstract: Aedes aegypti L. é um dos principais insetos causadores de doenças no mundo, sendo assim, é importante trabalhos envolvendo o seu manejo. O objetivo do projeto foi avaliar os efeitos da radiação gama do Cobalto-60 nas fases do ciclo evolutivo de A. aegypti, visando a aplicação da TIE. O trabalho foi realizado no Laboratório de Radiobiologia e Ambiente do Centro de Energia Nuclear na Agricultura (CENA/USP) em Piracicaba- SP. A criação do A. aegypti foi mantida nas instalações do laboratório, sob condições de 25±2°C, UR 50-70% e fotofase de 12 horas. A irradiação de todas as fases do ciclo foi realizada em uma fonte de Cobalto-60 tipo Gammacell-220, instalada no CENA/USP, nas seguintes doses: 0 (controle) até 70 Gy sob uma taxa de dose de 0,356 kGy/hora. Quando ovos foram irradiados, avaliou-se viabilidade contando o número médio de larvas L4, pupas e adultos fêmeas e machos emergidos. Foi também avaliado a porcentagem de eclosão em larvas L1 da geração F1. Para larvas irradiadas, avaliaram-se a o número médio de larvas L4, pupas, adultos fêmeas e machos emergidos, porcentagem de eclosão em larvas L1 e larvas L4 F1. Das pupas irradiadas, avaliaram-se a média de eclosão de larvas F1, de larvas L4 F1, porcentagem de pupas F1 e média de adultos machos e fêmeas F1. Em adultos irradiados, avaliaram-se a média de eclosão de larvas F1, larvas L4 F1, pupas F1 e adultos machos e fêmeas F1. Avaliaram-se parâmetros de competitividade e longevidade de machos F1. Os resultados mostraram que as doses esterilizantes para as fases irradiadas: ovo, larva e pupa foram de 15 Gy, 20 Gy e 60 Gy, respectivamente. Já para adultos da geração F,1 as doses de 45 Gy e 50 Gy para macho e fêmea. Para a fase adulta, doses de 40 Gy e 45 Gy foram esterilizantes para machos e fêmeas. No teste de competitividade, a proporção de 10 machos estéreis: 1 macho não irradiado: 1 fêmea não irradiada causou 92,2% de ovos inviáveis, na dose de 50 Gy. A longevidade dos machos foi reduzida em pupas e adultos irradiados com a dose de 40 Gy.

    Palavras-Chave: mosquitoes; sterile insect release; sterile male technique; irradiation; sterilization; radiosterilization; biological effects; pest control; viral diseases; comparative evaluations

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  • IPEN-DOC 26489

    GARCIA NETO, JOSE dos S. . Análise da viabilidade de um sistema de produção de energia limpa a partir da fonte primária solar convertida em energia química : o hidrogênio / Analysis of the viability of a clean energy production system from the solar primary source converted into chemical energy: hydrogen . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 225 p. Orientador: Adonis Marcelo Saliba Silva. DOI: 10.11606/D.85.2019.tde-03072019-141816

    Abstract: Frente a um panorama de escassez de combustível convencional fóssil e disponibilidade hidráulica para a produção de energia elétrica, fontes alternativas de energia renovável se tornam cada vez mais urgentes e necessárias. O hidrogênio é o elemento químico mais abundante disponível no planeta, tornando-se um potente candidato para suprir essa escassez de energia, pois, é capaz de conter um grande potencial energético comparável aos combustíveis fósseis, como a gasolina ou carvão. Sendo ele um vetor energético, não se tem a possibilidade de sua "extração" direta, porém, técnicas de obtenção do hidrogênio são bastante flexíveis, conhecidas e utilizadas comercialmente. Este trabalho teve como objetivo o estudo e construção de um sistema para produção de energia limpa a partir da produção de hidrogênio gasoso por eletrólise da água em meio alcalino, fazendo uso de um painel fotovoltaico como fonte alternativa de energia elétrica, bem como, a análise da eficiência energética desta produção. Para garantir a obtenção dos gases hidrogênio e oxigênio separadamente foi utilizada uma membrana separadora de gases, o Zirfon® Perl, permitindo a eletrólise pelo eletrolisador projetado e construído especificamente para este estudo, sem a necessidade de um sistema de circulação do eletrólito. Para uma análise comparativa das eficiências, produziu-se hidrogênio por eletrólise alcalina de uma solução aquosa de KOH (1M) com energia fornecida por uma fonte externa DC e por um painel solar ligado diretamente ao eletrolisador. O cálculo dessa eficiência foi feito pela relação entre a energia fornecida à eletrólise pelas fontes (solar e externa) e a energia do hidrogênio produzido com base no seu poder calorífico inferior (LHV). Além disso, curvas de carga de tensão e corrente do painel solar foram levantadas e estudadas para garantir a efetividade da ligação direta com o eletrolisador, bem como ensaios de EIE (Espectroscopia de Impedância Eletroquímica) foram realizados para análise da corrosão do eletrodo anódico e determinação da resistência ôhmica do sistema eletrolisador. Foram realizadas medidas e obtidas a eficiência energética com quatro montagens de sistemas eletrolisadores: 4 células com suprimento de energia por uma fonte externa DC, resultando em uma eficiência de 48,21%; 4 células e painel solar, 44,85%; 1 célula e fonte externa, 23,52 %; 1 célula e painel solar, 23,10%. Também foram calculadas eficiências energéticas da produção do hidrogênio em função do aumento de energia fornecida à eletrólise. Todas as aquisições dos parâmetros da eletrólise foram realizadas com um sistema automático projetado e construído especificamente para este trabalho, de forma que os dados foram obtidos a cada segundo, fornecendo valores em tempo real. Os resultados obtidos, tanto sobre os parâmetros importantes para que uma eletrólise para produção de hidrogênio possa se tornar eficiente energeticamente, como sobre as soluções para o desenvolvimento de um sistema com painel fotovoltaico que alimente diretamente o eletrolisador, serão de vital importância para continuação da pesquisa que envolva a utilização otimizada do hidrogênio em locais onde a energia elétrica proveniente de concessionárias seja escassa ou até mesmo inexistente.

    Palavras-Chave: solar cells; photovoltaic conversion; sodium hydroxides; membrane pores; electrolytes; alkaline hydrolysis; potassium hydroxides; hydrogen fuel cells; hydrogen generators; gases; zirconium alloys; electrolysis; energy efficiency; energy source development

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  • IPEN-DOC 26484

    SILVA, KATIA da C. . Síntese de material zeolítico de valor agregado a partir de fontes alternativas de silício e alumínio / Synthesis of value-added zeolitic material from alternative sources of silicon and aluminum . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 91 p. Orientador: Denise Alves Fungaro. DOI: 10.11606/D.85.2019.tde-26062019-084821

    Abstract: Amostras de cinzas geradas na combustão do carvão e de cinzas provenientes da queima dos resíduos da cana-de açúcar foram usadas como fonte de silício e alumínio para sintetizar zeólita 4A pelos métodos IZA e fusão alcalina seguida de tratamento hidrotérmico. A razão molar de Si/Al para a formação da zeólita foi ajustada pela adição de resíduo de alumínio da indústria terciária como fonte alternativa de alumínio. Os efeitos da temperatura, do tempo de fusão e o tempo da reação hidrotérmica foram investigados. Os resíduos e os produtos sintetizados foram caracterizados por diferentes técnicas, tais como: fluorescência de Raio X, difração de Raio X, capacidade de troca catiônica, entre outros. A zeólita sintetizada a partir de cinzas leves de carvão foi usada para a remoção de Cd2+ e Zn2+ de solução aquosa em sistema de batelada. Os dados de equilíbrio de adsorção foram avaliados usando-se equações não lineares dos modelos de Langmuir, Freundlich, Temkin e Dubinin-Radushkevich (D-R). Os modelos de D-R e Freundlich foram os que melhor se ajustaram aos dados experimentais do Cd2+ e Zn2+, respectivamente. A capacidade máxima de adsorção foi de 78,0 mg.g-1 para o Cd2+ e 35,8 mg.g-1 para o Zn2+. Os resultados mostraram que o resíduo de alumínio e as cinzas de carvão e de biomassa podem ser usados como matéria prima para obtenção de zeólita 4A, considerado um material de valor agregado e com promissoras propriedades de adsorção.

    Palavras-Chave: synthesis; zeolites; hydrothermal alteration; residues; coal; ashes; aluminium; bagasse; biomass; adsorption; property values; silicon alloys; waste processing

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  • IPEN-DOC 26464

    CARVALHO, LUMA R. de . Análise automatizada da frequência de micronúcleos em culturas celulares expostas a agentes genotóxicos físicos e quimícos / Automated analysis of the frequency of micronuclei in cell cultures exposed to physical and chemical genotoxic agents . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 58 p. Orientador: Daniel Perez Vieira. DOI: 10.11606/D.85.2019.tde-22072019-075930

    Abstract: O ensaio de frequência de micronúcleos é uma técnica importante utilizada para avaliar danos genotóxicos de agentes químicos ou físicos (como radiação ionizante) em células, baseado na quantificação de células contendo micronúcleos, que são fragmentos derivados de DNA danificado com coloração semelhante ao dos núcleos principais, mas com 5 a 30% do seu tamanho. Tradicionalmente, este ensaio é realizado usando microscopia de coloração convencional de acordo com Giemsa, mas atualmente esta técnica está sendo atualizada para uma abordagem automatizada que se baseia na dissolução da membrana plasmática por detergentes levando em conta apenas núcleos e micronúcleos com seu DNA corados por corantes fluorescentes, que pode discriminar núcleos de células viáveis dos das células inviáveis e permite a contagem por citometria de fluxo. Este trabalho avaliou a extensão de dano genotóxico radioinduzido por radiação gama (60Co) em doses entre 0,5 e 16Gy, e o potencial genotóxico de três peptídeos utilizados em medicina nuclear (PSMA-617, PSMA-11 e Ubiquicidina 29-41). As membranas celulares foram lisadas na presença dos corantes SYTOX® Green e EMA, e núcleos marcados com os dois fluorocromos foram considerados provenientes de células inviáveis e, portanto, removidos da análise. As quantidades de micronúcleos (porcentagem de eventos) nas amostras, foram proporcionais às doses de radiação, e puderam ser ajustadas a um modelo linear-quadrático (R2 = 0,993). Somente doses mais altas (8 e 16 Gy) e controles positivos induziram aumentos relevantes nas quantidades de micronúcleos. Os radiofármacos foram testados com concentrações de 0,1x, x, 10x e 100x a concentração utilizada em adultos, e não induziram dano em concentrações praticáveis.

    Palavras-Chave: cell cultures; gene regulation; dna; chelating agents; toxic frequency control; microstructure; substances control acts; physical properties; chemical properties; radiopharmaceuticals; gamma radiation

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  • IPEN-DOC 26433

    SOUZA, ANDERSON L. de . Tratamento de efluentes provenientes da indústria curtidora, empregando acelerador de elétrons / Treatment of effluents from tannery, using electron accelerator . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 98 p. Orientador: Sueli Ivone Borrely. Coorientador: Maria Aparecida Faustino Pires. DOI: 10.11606/D.85.2019.tde-21112019-155745

    Abstract: A indústria curtidora brasileira está entre os principais países produtores de couro do mundo. O processo produtivo de um curtume tem por finalidade transformar a pele animal em couro e envolve uma sequência de reações químicas complexas e o consumo significativo de água. O efluente do processo de curtimento se caracteriza pela alta salinidade, alto teor de matéria orgânica, presença de corantes, surfactantes, sulfeto e cromo. Os curtumes normalmente possuem estações de tratamento de efluentes, visando minimizar seus impactos ambientais e atender à legislação vigente para padrões de lançamento. Dentre as tecnologias alternativas de tratamento de efluentes, têm-se os Processos de Oxidação Avançada (POA's). O objetivo deste trabalho foi avaliar a eficiência da radiação ionizante para o tratamento de efluentes da indústria curtidora, empregando acelerador de elétrons. Os efluentes brutos de um curtume foram irradiados com doses de 10, 20, 30, 40, 50 e 60 kGy. A eficiência deste processo e do tratamento convencional (coagulação/floculação) foram avaliadas pelos resultados dos parâmetros de cromo hexavalente, demandas química e bioquímica de oxigênio (DQO e DBO), óleos e graxas, sólidos suspensos totais e sulfeto, além do ensaio de toxicidade aguda com o microcrustáceo Daphnia similis. A radiação ionizante mostrou-se eficiente, alcançando remoção média para DBO (29,4%), DQO (20,2%), óleos e graxas (26,7%), sólidos suspensos totais (36,6%) e sulfeto (74,3%). Quanto ao parâmetro ecotoxicidade, as amostras originalmente apresentaram-se com elevada toxicidade para efeito agudo em dafnídeos e a irradiação resultou em remoção média de 34,0% da toxicidade nos efluentes irradiados.

    Palavras-Chave: liquid wastes; waste water; waste processing; leather; industrial wastes; toxicity; acute irradiation; daphnia; microorganisms; linear accelerators; electron beams; ionizing radiations

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  • IPEN-DOC 26432

    ALVES, MAURICIO B. . Avaliação do organismo ouriço do mar (Lytechinus variegatus e Sterechinus neumayeri) como biomonitor de contaminação por elementos tóxicos e traço em ambientes marinhos : costa brasileira e região Antártica / Evaluation of sea urchin (Lytechynus variegatus and Sterechinus neumayeri) as biomonitor of contamination by toxic and trace elements in marine environments: Brazilian coast and Antarctic region . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 176 p. Orientador: Déborah Inês Teixeira Fávaro. DOI: 10.11606/D.85.2019.tde-17102019-134707

    Abstract: A contaminação de ecossistemas marinhos costeiros pode ser avaliada por meio de programas de biomonitoramento, utilizando-se organismos indicadores. No presente estudo, utilizou-se o organismo ouriço do mar para fins de biomonitoramento passivo para elementos possivelmente tóxicos e traço. Foram analisados tecidos de ouriços-do-mar provenientes da região de São Sebastião, São Paulo (espécie Lytechinus variegatus) e da região da Estação Comandante Ferraz, Antártica (espécie Sterechinus neumayeri), em dois locais (não impactado e impactado). Determinaram-se as concentrações dos elementos: As, Ba, Br, Ca, Co, Cr, Fe, K, Na, Rb, Sc, Se e Zn por meio da técnica de análise por ativação neutrônica instrumental (INAA) e dos elementos potencialmente tóxicos (Cd, Hg, Ni e Pb), e Cu por espectrometria de absorção atômica (AAS). Os resultados de concentração obtidos foram comparados com outros organismos utilizados em biomonitoramento e com os valores de concentração em sedimentos, para cada região estudada neste trabalho. Os elementos Cd, Cr, Cu, Fe, Hg, Ni, Sc e Zn apresentaram maior concentração em São Sebastião (local mais impactado). Para a região Antártica, os ouriços da região da Estação Ferraz (local possivelmente mais impactado) apresentaram maiores níveis de Br, Co, Cr, Cs, K, Se e Zn. Para a espécie L. variegatus este estudo indicou a possibilidade de biomonitorar Cd, Ni e Sc independente do sexo; os elementos Co, Cr, Hg, Pb e Cu nas fêmeas e Zn, nos machos. Para a espécie S. neumayeri os resultados sugeriram a possibilidade de biomonitoramento para os elementos Co, Cr, Cu, Fe, Pb, Se e Zn. O presente estudo contribuiu também para o conhecimento da composição mineral das espécies de ouriço-do-mar L. variegatus e S. neumayeri.

    Palavras-Chave: aquatic organisms; sea urchins; cytological technique; toxicity; bioremediation; sediments; trace amounts; elements; environmental impacts; contamination; water pollution monitors; water treatment; oxide minerals; uranium minerals; geochemistry; neutron activation analysis; absorption spectroscopy; brazil; antarctic regions

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  • IPEN-DOC 26421

    BETINI, EVANDRO G. . Avaliação das propriedades estruturais e térmicas de soldas realizadas em aço inoxidável duplex para aplicação em embalado para o transporte de substâncias radioativas / Assessment of the thermal and structural properties of duplex stainless-steel welded plates for application in container for transport of radioactive material . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 128 p. Orientador: Jesualdo Luiz Rossi. DOI: 10.11606/T.85.2019.tde-04112019-113030

    Abstract: Neste trabalho foram avaliadas propriedades térmicas de soldas em aço inoxidável duplex UNS32304 observando a influência do processo de soldagem GTAW pulsado sobre as características estruturais desse material. Este aço apresenta-se como material candidato a revestimento externo dos receptáculos de contenção para transporte de substâncias que sejam fontes de alta radioatividade, em especial 99Mo, com atividade acima de 0,6 TBq (16,2 Ci). O transporte de radiofármacos é definido pela norma CNEN NE-5.01 que exige um embalado com requisitos de segurança determinados pela resistência mecânica ao impacto, baixa fadiga térmica e resistência à corrosão já conferida pela grade duplex UNS S32304. Chapas de 1,8 mm de aço inoxidável duplex foram soldadas pelo processo GTAW variando os gases de proteção entre Ar puro e Ar + 2%N2 sem metal de adição. Os ciclos térmicos de soldagem foram estudados por um sistema de termopares tipo K e S fixados próximos à linha de soldagem. A distribuição de temperatura ao longo do cordão de solda foi determinada alcançando valores dentro do intervalo de transformação de fase desse material. Através de uma avaliação quantitativa e semiquantitativa de elementos foi calculada a relação Creq/Nieq para os grãos de ferrita, austenita e austenita secundária da zona solidificada, ZAC e metal de base. Mapeamentos e perfis transversais de cromo, níquel e nitrogênio foram gerados por microssonda eletrônica mostrando as alterações desse elemento devido os ciclos térmicos de soldagem obtidos. A adição de 2% de N2 no gás de proteção provocou maior formação de austenita na zona solidificada quando comparada com a soldagem sem adição de N2, sendo a atmosfera mais adequada para soldagem em aços inoxidáveis duplex. Além disso, essa mistura de gases provocou leve aumento da dureza na zona solidificada. As propriedades termofísicas foram estudadas por método de flash de laser (MFL) utilizado para a determinação da difusividade térmica do material na direção da espessura e o calor específico da zona solidificada foi obtido via análises térmicas por calorimetria exploratória diferencial (DSC). Foram obtidas medidas de porosidades e massa específica da zona solidificada e comparada com o metal de base e metal como recebido. Com estas informações foi possível avaliar a condutividade térmica do material pós processo de soldagem. O aumento da condutividade térmica foi encontrado para ambas as amostras soldadas e sugerem correlação com aumento da fase ferrítica e a diminuição da porosidade também observadas para zona solidificada.

    Palavras-Chave: gas tungsten-arc welding; stainless steels; thermodynamic properties; physical properties; transport; packaging; radiopharmaceuticals; impact parameter; mechanical properties; resistance welding; calorimetry; differential thermal analysis; materials testing; performance; safety standards; radiation protection

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  • IPEN-DOC 26416

    LITVAC, DANIEL . Desenvolvimento de um kit postal dosimétrico para calibração de aplicadores clínicos de betaterapia no Brasil / Development of a dosimetric postal kit for calibration of clinical beta therapy applicators in Brazil . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 93 p. Orientador: Linda Viola Ehlin Caldas. DOI: 10.11606/D.85.2019.tde-21112019-165533

    Abstract: O sistema de saúde no Brasil, como um todo, possui déficits em mão de obra e em infraestrutura. A betaterapia é uma das alternativas que o Sistema Único de Saúde e serviços particulares implantam para suprir a demanda. Aplicadores clínicos de 90Sr/90Y são utilizados para tratamentos dermatológicos e oftálmicos, substituindo o uso de aceleradores lineares, porque são de custo mais baixo, mais práticos e possuem 28,8 anos de meia-vida. A calibração e a recalibração periódica destes aplicadores, para verificação da taxa de dose absorvida, são essenciais para garantir a segurança nos tratamentos clínicos. Trabalhos de pesquisas mostram discrepâncias entre a calibração do fabricante e a realizada em laboratórios, podendo ter consequências danosas para os pacientes. Além disso, são poucos os laboratórios de calibração do tipo padrão primário para fontes de radiação beta no mundo. Na América Latina não existem laboratórios de calibração com este perfil. Foi desenvolvido neste trabalho um kit postal dosimétrico que permitiu a recalibração dos aplicadores clínicos utilizados em hospitais, de maneira prática, rápida e com instruções, por meio de seu envio aos proprietários, e depois retornando ao IPEN para posterior avaliação. Para isto, alguns materiais dosimétricos foram caracterizados em feixes padronizados de radiação beta, utilizando as técnicas de termoluminescência e luminescência opticamente estimulada para comparação de resultados da resposta quanto à reprodutibilidade, linearidade, curva dose-resposta e dependência angular, definindo as condições mais adequadas e o grupo de dosímetros para calibração dos aplicadores clínicos.

    Palavras-Chave: radiotherapy; dosimetry; beta decay; radiation doses; dose-response relationships; quality control; quality assurance; testing; clinical trials; performance; uses; tissue distribution; skin; eyes; radiation metrology; calibration; brazil

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  • IPEN-DOC 26412

    CAVALHEIRA, ELTON D. . Caracterização mecânica e microestrutural do zircaloy-4 obtido por HD e metalurgia do pó / Mechanical and microstructural characterization of zircaloy-4 obtained by HD and powder metallurgy . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 74 p. Orientador: Hidetoshi Takiishi. DOI: 10.11606/D.85.2019.tde-18112019-111622

    Abstract: A etapa de usinagem para fabricação de tubos e tampões (end caps) de Zircaloy-4 (Zr-4) utilizados em reatores nucleares à água pressurizada (reatores PWRs) geram grandes quantidades de rejeitos deste material. Devido ao alto custo do Zr-4 faz-se necessário sua reciclagem, que representa uma grande economia para a política Nuclear Brasileira e também evita seu descarte para o meio ambiente. Neste trabalho, os rejeitos da usinagem do Zr-4 foram aquecidos em atmosfera de hidrogênio (923 K), sendo o pó resultante desta etapa, peneirado em malha 200 e 325 mesh (<75 e <45 μm). Nesta etapa, foram retirados os materiais que não absorvem hidrogênio proveniente da usinagem, diminuindo a contaminação final por Fe da liga Zr-4. A moagem foi realizada em moinho de alta energia, utilizando pote e esferas de zircônia para diminuir a contaminação do pó. Os experimentos foram realizados em diferentes tempos de moagem (0 a 120 min). A amostra foi prensada a 200 MPa (prensagem isostática) e sinterizada a 1423 K por 10 h. A microestrutura foi analisada por microscopia eletrônica de varredura (MEV) e foi determinada a microdureza Vickers. Os resultados mostraram que após 60 min de moagem o tamanho médio das partículas foi de 2,4 μm. a microdureza Vickers após sinterização foi de 425 HV e tamanho médio de grão em torno de 50 μm. As amostras apresentaram valores de densidade hidrostática de 99% em relação à teórica, e a microestrutura apresentou morfologia típica do Zr-4 da fase α e grãos equiaxiais. Para redução de áreas de armazenamento dos cavacos obteve-se uma redução de 27 vezes no volume ocupado após hidretação, cominuição e prensagem. Foi possível usinar os tampões a partir das amostras com menor medida de microdureza.

    Palavras-Chave: powder metallurgy; zircaloy 4; tubes; capsules; sample preparation; elements; pwr type reactors; environmental policy; contamination; microstructure; microhardness; vickers hardness; indentation testing; hardness; sintering; materials testing; hydrostatics; power density; materials processing reactors; materials recovery; waste processing; scanning electron microscopy

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  • IPEN-DOC 26411

    SILVA, EZEQUIEL da . Avaliação do desempenho de câmaras de ionização para radioproteção em condições ambientais variadas / Performance evaluation of ionization chambers for radiation protection in various environmental conditions . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 74 p. Orientador: Maria da Penha Albuquerque Potiens. DOI: 10.11606/D.85.2019.tde-30102019-105510

    Abstract: Esse trabalho apresenta uma proposta metodológica para verificar o desempenho das câmaras de ionização comerciais para radioproteção utilizadas no levantamento radiométrico em radiodiagnóstico nas cinco regiões brasileiras para os parâmetros de umidade e temperatura.Para isso, foi construído um sistema de climatização para simular as diversas condições ambientais as quais estes instrumentos de medição são expostos quando utilizados em campo.O presente trabalho teve como objetivo diminuir erros na medição em função do desempenho das câmaras de ionização, aumentando a segurança dos trabalhadores ocupacionalmente expostos, dos usuários, do público em geral e impactar na redução com custos estruturais tais como troca de visoresplumbíferos, revestimento adequado das paredes das salas de radiologia dentre outras ações de radioproteção.Foram simuladas as condições climáticas das cinco regiões do território nacional, todos os estados simulados apresentaram coeficientes de variação em relação as taxas de dose acumulada menores que 5%. O sistema de climatização desenvolvido de baixo custo apresentou boa eficiência nas faixas de umidade no intervalo de 40% a 100% e para simulações partindo da temperatura ambiente até 50 °C. O sistema de climatização pode ainda ser utilizado para tratar a umidade dos instrumentos de medição melhorando significativamente sua performance.

    Palavras-Chave: dosimetry; ionization chambers; quality control; testing; performance; uses; exposure chambers; humidity; well temperature; controlled atmospheres; radiation doses; absorbed dose range; personnel; employment; nuclear medicine; radiation protection

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  • IPEN-DOC 26408

    COSTADELLE, EWERTON L. . Modernização de máquina de ensaio de fluência para estudo da liga Ti-6AI-4V / Creep-test machine modernization for Ti-6Al-4V alloy study . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 74 p. Orientador: Antonio Augusto Couto. DOI: 10.11606/D.85.2019.tde-22112019-115423

    Abstract: Este trabalho teve como objetivo desenvolver um conjunto de modernização para um equipamento de ensaio de fluência da marca The Electronic and Mechanical Engineering Co. Ltd. (EMEC), de propriedade do IPEN. Para tanto, obteve características mecânicas. Além disso, modelou e simulou o comportamento do dispositivo de aplicação de tração. Este estudo também desenvolveu um dispositivo eletrônico de baixo custo baseado na plataforma Arduino para registrar a deformação e controlar a temperatura da amostra em torno de ±2°C. Para validar os resultados, foram realizados ensaios em amostras do mesmo lote. Tanto no equipamentos EMEC quanto em outros dois modelos diferentes, eles eram um Zwick (fabricado em 2015 e pertencente à UPM) e um Mayes (modernizado há cerca de 20 anos e pertencente ao DCTA). No EMEC a taxa de fluência estacionária para a liga Ti6Al4V foi de 2,71 x 10-4 s-1 e tempo total até a ruptura foi de 619 s, no Zwick estes valores foram de 2,85 x 10-4 s-1 e 615 s, respectivamente, e no Mayes, 5,04 x 10-4 s-1 e 321 s.

    Palavras-Chave: mechanical properties; thermodynamic properties; thermoelectric conversion; analog-to-digital converters; creep; electrical equipment; quality control; testing; performance; uses; retrofit; titanium alloys

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  • IPEN-DOC 26407

    MELO, GLEISER R. de . Desenvolvimento de estação de monitoramento para registro de temperatura, umidade e tensão de alimentação de detectores HPGe-Germânio Hiper-Puro / Development of monitoring station to record temperature, humidity and supply voltage of HPGe - Hyper-Pure Germanium detectors . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 81 p. Orientador: Frederico Antonio Genezini. DOI: 10.11606/D.85.2019.tde-05112019-151542

    Abstract: Um sistema baseado em micro controladores e sensores de baixo custo para o monitoramento ambiental dos laboratórios onde os detectores de HPGe são utilizados foi desenvolvido, visando a automatização da tarefa de controle das condições necessárias para garantir a qualidade das medidas, que tem sido realizado há muitos anos de forma manual, nem sempre com a frequência necessária. A proposta deste trabalho foi desenvolver uma estação de monitoramento, juntamente com seu software controlador, baseada em um micro controlador Arduino UNO equipada com quatro sensores termohigrômicos para monitorar diferentes partes do ambiente a qual o detector de Germânio hiper-puro está instalado, um sensor de tensão para monitorar sua tensão de alimentação, além de um termopar para monitorar o interior do dewar. Um software baseado na linguagem C-Sharp, e um banco de dados MySQL dedicado, foi desenvolvido com interface amigável e permitindo exportar os resultados obtidos na forma de relatórios. O sistema foi testado em um detector Canberra modelo GC2018, onde os quatro termohigrômetros foram posicionados em diferentes locais, permitindo monitorar as condições com intervalos determinados de no mínimo um minuto. Para garantir a confiabilidade das medidas os sensores foram calibrados por meio de medidas em ambientes com condições variadas e monitorado por aparelho termohigrômetro com certificado de calibração. Foi verificado que apenas um sensor dentro e outro fora da blindagem são necessários. O termopar se mostrou adequado para monitorar a refrigeração do detector e o sensor de tensão não se mostrou adequado. As medidas de umidade e temperatura foram feitas junto com medidas de resolução dos detectores e não foi possível observar correlação entre os resultados, indicando que o detector é pouco sensível às variações observadas. O sistema pode ser replicado se desejado, com os aprimoramentos sugeridos neste estudo, resultando em uma estação de baixo custo e eficiente, inclusive no próprio LAN para outros equipamentos.

    Palavras-Chave: dosimetry; semiconductor detectors; high-purity ge detectors; quality control; testing; performance; uses; humidity; well temperature; controlled atmospheres; programming; computers; control equipment

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  • IPEN-DOC 26519

    SOUZA, LUIZA F. de; CALDAS, LINDA V.E. ; JUNOT, DANILO O.; SILVA, ANDERSON M.B.; SOUZA, DIVANIZIA N.. Thermal and structural properties of magnesium tetraborate produced by solid state synthesis and precipitation for use in thermoluminescent dosimetry. Radiation Physics and Chemistry, v. 164, p. 1-5, 2019. DOI: 10.1016/j.radphyschem.2019.108382

    Abstract: Magnesium tetraborate is a phosphor with relevant characteristics for radiation dosimetry purposes. One of the main challenges on this material is still the understanding of its structure and luminescent processes involved in dosimetric performance. In this work, all the steps of the material production through DTA/TG, XRD and SEM techniques were evaluated to understand the main physical and chemical changes during the thermal process (calcination and sinterization) to produce the MgB4O7 samples. Two synthesis processes of MgB4O7 were studied: precipitation (P.S) and solid state (S.S). Finally, the luminescence efficiency of the pellets was investigated in function of different sintering temperatures. The initial stage of DTA/TG curves of the material just after the mixing of starting materials, regardless the synthesis, is marked by endothermic events caused by dehydration, decomposition of hydroxyl groups and hydrated borate phases. At higher temperatures, the curves are marked by exothermic events related to crystalline transitions, but the peak obtained for the S.S is better defined in comparison to P.S. Moreover, the DTA/TG analyses of the pellets prior and after the sinterization, showed that the process is more relevant for the MgB4O7 pellets produced by S.S (950 °C), dramatically reducing its higroscopicity. The SEM images reinforce the importance of the sintering process to create a resistant detector and with a more homogenous and cohesive surface, therefore increasing it luminescence properties. The thermoluminescent (TL) sensitivity of MgB4O7:Dy0,5% pellets produced via S.S, sintered at 950 °C, is 4 times higher compared to the ones sintered at 950 °C, via P.S. The materials produced via P.S did not present relevant changes in their TL sensitivity for sintering temperatures above 400 °C.

    Palavras-Chave: dosimetry; magnesium; dysprosium; sintering; scanning electron microscopy; thermoluminescence; thermal analysis; synthesis

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  • IPEN-DOC 26518

    NARDINI, ELISA F.; ALMEIDA, THIAGO S.; YOSHIMURA, TANIA M. ; RIBEIRO, MARTHA S. ; CARDOSO, RIELSON J.; GARCEZ, AGUINALDO S.. The potential of commercially available phytotherapeutic compounds as new photosensitizers for dental antimicrobial PDT: a photochemical and photobiological in vitro study. Photodiagnosis and Photodynamic Therapy, v. 27, p. 248-254, 2019. DOI: 10.1016/j.pdpdt.2019.05.027

    Abstract: The present study evaluated the effectiveness of extracts of commercially available Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum as photosensitizers in Antimicrobial Photodynamic Therapy (aPDT). Each photosensitizer (PS) was analyzed in a spectrophotometer between 350 and 750 nm to determine the ideal light source. Once the absorption bands were determined, three light sources were selected. To determine the concentration of use, the compounds were tested at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, the PSs were evaluated for dark toxicity and phototoxicity on fibroblast and bacteria culture. Each compound was then irradiated with each light source and evaluated for the production of reactive oxygen species (ROS). The bacterial reduction was tested on E. faecalis culture in planktonic form and on biofilm using an energy of 10 J and an Energy Density of 26 J/cm2. The tested compounds exhibited light absorption in three bands of the visible spectrum: violet (405 nm), blue (460 nm) and red (660 nm). At a 1:6 concentration, none of the compounds caused tooth staining as they did not exhibit significant toxicity in the cells or bacterial suspension. Additionally, significant ROS production was observed when the compounds were irradiated at each wavelength. When aPDT was performed on the plactonic and biofilm bacteria, significant microbial reduction was observed in both cases, reaching a reduction of up to 5Logs. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum exhibited potential for use as photosensitizing agents in aPDT.

    Palavras-Chave: plants; biological materials; medicinal plants; photosensitivity; photochemical reactions; in vitro; dentistry; antimicrobial agents; chemotherapy; bacteria; streptococcus; therapy; photochemistry; teeth

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  • IPEN-DOC 26516

    SILVA, REJANE M.P. da ; MILAGRE, MARIANA X. ; OLIVEIRA, LEANDRO A. de; DONATUS, UYIME ; ANTUNES, RENATO A.; COSTA, ISOLDA . The local electrochemical behavior of the AA2098‐T351 and surface preparation effects investigated by scanning electrochemical microscopy. Surface and Interface Analysis, v. 51, n. 10, p. 982-992, 2019. DOI: 10.1002/sia.6682

    Abstract: In this work, scanning electrochemical microscopy (SECM) measurements were employed to characterize the electrochemical activities on polished and as‐received surfaces of the 2098‐T351 aluminum alloy (AA2098‐T351). The effects of the near surface deformed layer (NSDL) and its removal by polishing on the electrochemical activities of the alloy surface were evaluated and compared by the use of different modes of SECM. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were also employed to characterize the morphology of the surfaces. The surface chemistry was analyzed by X‐ray photoelectron spectroscopy (XPS). The surface generation/tip collection (SG/TC) and competition modes of the SECM were used to study hydrogen gas (H2) evolution and oxygen reduction reactions, respectively. H2 evolution and oxygen reduction were more pronounced on the polished surfaces. The feedback mode of SECM was adopted to characterize the electrochemical activity of the polished surface that was previously corroded by immersion in a chloride‐containing solution, in order to investigate the influence of the products formed on the active/passive domains. The precorroded surface and as‐received surfaces revealed lower electrochemical activities compared with the polished surface showing that either the NSDL or corrosion products largely decreased the local electrochemical activities at the AA2098‐T351 surfaces.

    Palavras-Chave: aluminium alloys; electrochemistry; scanning electron microscopy; corrosion; electrochemical corrosion; surface finishing; surface properties; lithium alloys

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  • IPEN-DOC 26514

    SOARES, J.J.S. ; JACOVONE, R.M.S. ; SANTOS, P.S. ; ZAIM, M.H.; FARIA, D.L.A.; SAKATA, S.K. . The effect of gamma radiation on the structure of graphene oxide and graphene oxide functionalized with amino-PEG. Brazilian Journal of Radiation Sciences, v. 7, n. 3, p. 1-12, 2019. DOI: 10.15392/bjrs.v7i3.837

    Abstract: Covalent functionalization of graphene oxide (GO) with polyethylene glycol (PEG) has been widely used in drug delivery systems. This nanocomposite exhibits excellent stability in the presence of high concentrations of salts and proteins and shows low toxicity compared to its raw form. However, it must be sterilized prior to use in medical devices, and for this purpose, the gamma irradiation shows a promising option. Sterilization by ionizing energy through gamma rays, generated by Cobalt-60 self-disintegration, consists in exposing the materials to short electromagnetic waves. The irradiation process provides substantial advantages when compared to thermal and chemical processes, such as, more precise control of the process, lower energy consumption, and less environmental pollution. In this work the effects of gamma radiation on GO and GO functionalized with amino-PEG (GO-PEG-NH2) irradiated with doses (15, 25, 35 and 50 kGy) at rate dose of 7.3 kGy.h-1 were evaluated. The analyses were performed by Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The results showed that gamma radiation up to 50 kGy did not cause any defects on the nanomaterials.

    Palavras-Chave: cobalt 60; dose rates; fourier transformation; gamma radiation; graphene; infrared spectra; polyethylene glycols; radiation doses; radiation effects; raman spectroscopy; sterilization; synthesis

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  • IPEN-DOC 26513

    SANTOS, ADIMIR dos ; DINIZ, RICARDO . The correlation matrix for the effective delayed neutron parameters of the IPEN/MB-01 reactor. Annals of Nuclear Energy, v. 136, p. 1-7, 2020. DOI: 10.1016/j.anucene.2019.107008

    Abstract: The correlation matrix for the effective delayed neutron parameters of the IPEN/MB-01 reactor has been successfully built in this work. A standard procedure employed in several least-squares approaches was adopted to cope with this task. One of the most important applications of the effective delayed neutron parameters is to serve as input data for the relationship between reactivity and asymptotic period of a nuclear reactor given by the Inhour equation. Employing this equation, the reactivity was calculated for several periods both negative and positive. The reactivity error propagation was considered with and without the correlation matrix. The analyses of this procedure reveal that the consideration of the correlation matrix is very important. In general, the introduction of the correlation matrix reduces the overall uncertainty by a reasonable amount. There are huge cancellations in the uncertainty analyses. The analyses also reveal that the uncertainty in the reactivity will depend on the specific period range where this quantity is considered. Considering the correlation and for most of the period range considered, the reactivity uncertainties for negative periods are around 3.5% while for positive ones they are nearly 2%. If the correlation matrix is not considered the reactivity uncertainties are as high as 6%. All uncertainties considered in this work are 1-r values. There are two extreme cases where the correlation matrix plays no role; very large negative periods and very small positive periods. In the first case, the first decay constant plays a fundamental role while in the second the prompt neutron generation is of major importance. The experiments performed at the IPEN/MB-01 reactor and evaluated for inclusion in the IRPhE handbook for the determination of the effective delayed neutron parameters will be extremely benefited considering the inclusion of their correlation matrix. The final product can be considered extremely useful to validate methods and nuclear data related to the reactivity determination of thermal reactors fueled with Uranium.

    Palavras-Chave: reactivity; reactivity coefficients; delayed neutrons; transients; correlations; matrix elements; reactor noise; reactor components; thermal reactors; brazilian cnen

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  • IPEN-DOC 26512

    ROSSI, WAGNER de ; VIEIRA, ALEXANDRE. Texturization of engine components with shaped ultrashort laser pulses. Journal of Laser Micro Nanoengineering, v. 14, n. 2, p. 142-146, 2019. DOI: 10.2961/jlmn.2019.02.0005

    Abstract: The aim of this work was to texturize surfaces of steel engine components to reduce the coefficient of dynamic friction and wear between two surfaces. The elements of the texture had the shape of a spherical half-shell and were produced by the overlap of femtosecond laser pulses with donut shape. The incubation effect was estimated using the D-scan method to relate the ablation threshold to the number of overlapping pulses. Thus, the control of the focal position of the laser beam and the number of overlapped pulses, taking into account the effects of incubation, made it possible to obtain this type of dimple with controlled shape and size. A distribution of dimples with density of 11% caused an 18% reduction in the coefficient of friction in a tribological pair DIN 16MnCr5 and SAE 52100 steel sphere.

    Palavras-Chave: texture; lasers; machining; microstructure; laser radiation; laser beam machining; steels; beam shaping; friction

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  • IPEN-DOC 26511

    GONÇALVES, KARINA de O. ; SILVA, FLAVIA R. de O. ; VIEIRA, DANIEL P.; COURROL, LILIA C.. Synthesis and characterization of aminolevulinic acid with gold and iron nanoparticles by photoreduction method for non‑communicable diseases diagnosis and therapy. Journal of Materials Science: Materials in Electronics, v. 30, n. 18, SI, p. 16789-16797, 2019. DOI: 10.1007/s10854-019-01337-6

    Abstract: Non-communicable diseases (NCDs) are a group of chronic diseases resulted by genetic, epigenetic and environmental factors and life style. The main types of NCDs are cardiovascular diseases and cancers. Some of therapeutic treatments for NCDs induce severe cytotoxicity to normal cells. New treatments as photodynamic and sonodynamic therapies have been proposed trying to improve the cure rate and reduce the side-effects. In these treatments certain drugs as porphyrins precursors associated to metal nanoparticles (MNPs) have become of extreme interest since have high targeting ability and potentiality to destroy tumor tissues. MNPs can induce cell death through various processes, including reactive oxygen species (ROS) generation and DNA damage, among others. In this work, we describe synthesis of MNPs by photoreduction with aminolevulinic acid (ALA), a protoporphyrin IX precursor. To obtain ALA:MNPs (M = Au or/and Fe), ALA, polyethylene glycol, and Tetrachloroauric acid and/or iron powder water solutions were irradiated by Xenon lamp. The UV–vis spectra, transmission electron microscopy and zeta potential were measured to characterize nanoparticles. The proposed mechanism of nanoparticle formation was described from a physicochemical perspective. The THP-1 macrophages cytotoxicity was determined, and photodynamic therapy (PDT) with high power LED at 590 nm for 2 min were performed. The results have suggested that the gold/iron nanoparticles interfere in the selectivity of iron transport across the mitochondrial inner membrane and enhance the effectiveness of the PDT acting as important agent for NCDs control.

    Palavras-Chave: aminolevulinic acid; synthesis; gold; iron; nanoparticles; reduction; diseases; toxicity

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  • IPEN-DOC 26510

    THEOPHILO, C.Y.S. ; FIGUEIRA, R.C.L.; COLABUONO, F.I.; MONTONE, R.C.; MOREIRA, E.G. . Study on elements concentrations on seabird feathers by instrumental neutron activation analysis. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.599

    Abstract: Seabirds are very sensitive to environmental changes and due to their large longevity, they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose was to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were collected by the Albatross Project with permission of collection given by ICMBio (SISBIO 19560-1). The specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a High Purity Germanium (HPGe) detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds.

    Palavras-Chave: birds; concentration ratio; ecological concentration; elements; feathers; high-purity ge detectors; neutron activation analysis; gamma spectroscopy

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  • IPEN-DOC 26509

    OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V. ; SILVA, REJANE M.P. da ; LIMA, NELSON B. de ; OLIVEIRA, JEFFERSON T.D. de; OLIVEIRA, LEANDRO A. de; ANTUNES, RENATO A.. Structural, adhesion and electrochemical characterization of electroless plated Ni-P-carbon black composite films on API 5L X80 steel. Journal of Materials Engineering and Performance, v. 28, n. 8, p. 4751-4761, 2019. DOI: 10.1007/s11665-019-04245-2

    Abstract: In this work, composite Ni-P-carbon black coatings were obtained by electroless deposition on API 5L X80 substrates. The effect of carbon black on structural, adhesion and electrochemical properties of the plated samples was evaluated. Scanning electron microscopy analyses were carried out to examine the top surface and cross section of the films. Scratch tests were employed to evaluate coating adhesion properties. Potentiodynamic polarization tests were carried out to investigate the global electrochemical behavior of the deposited layers. Scanning electrochemical microscopy (SECM) was employed to measure local electrochemical activity over the coated surfaces. The carbon black concentration markedly affects the morphology, adhesion and electrochemical properties of the Ni-P-carbon black layers. The results point to an optimum carbon black content to achieve the best performance against corrosion. The coatings obtained at a carbon black concentration of 0.25 g L21 provided the best protection ability. The results are discussed with respect to coating morphology, adhesion and electrochemical activity.

    Palavras-Chave: nickel; phosphorus; nickel phosphides; carbon black; composite materials; corrosion; electrochemistry; scanning electron microscopy; electrochemical corrosion

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  • IPEN-DOC 26508

    BENTO, RODRIGO T. ; FERRUS FILHO, ANDRE; FUMAGALLI, MARCO A.. Structural design and stress analysis of a high‑speed turbogenerator assembly supported by hydrodynamic bearings. Journal of the Brazilian Society of Mechanical Sciences and Engineering, v. 41, n. 10, p. 1-9, 2019. DOI: 10.1007/s40430-019-1946-x

    Abstract: Turbine and bushing bearing are the most critical components of high-speed machines. This paper describes the design of a high-speed turbine supported by hydrodynamic bearings. The mathematical dimensioning and the FEM analysis are presented to validate the mechanical strength of the turbine and the bushing bearing models. Fatigue life and factor of safety are also determined. The simulations show that the maximum von Mises stress values obtained are associated with the centrifugal force generated by the system rotational movement. The results variation is mainly due to the properties of the materials proposed. For the turbine, 7075-T6 aluminum alloy and SAE 4340 steel obtained satisfactory behavior under a constant operating speed of 30,000 RPM. For the hydrodynamic bearing, the TM23 bronze alloy exhibited excellent results, without fracture, and low mechanical deformation. The models exhibited a great potential employment in several applications, such as biogas systems to generate electrical energy, and educational test bench for thermodynamic and tribological simulations.

    Palavras-Chave: hydrodynamics; bearings; finite element method; thermal stresses; turbines; stress analysis; steam turbines; turbogenerators; machinery

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  • IPEN-DOC 26506

    FONSECA, GABRIEL P.; BELLEZZO, MURILLO ; YORIYAZ, HELIO . Sistemas de planejamento em radioterapia / Radiotherapy planning systems. Revista Brasileira de Física Médica, v. 13, n. 1, p. 92-98, 2019. DOI: 10.29384/rbfm.2019.v13.n1.p92-98

    Abstract: Este artigo apresenta uma breve descrição do histórico do desenvolvimento de sistemas de planejamento, seguida da descrição dos atuais sistemas comerciais utilizados nos centros de radioterapia no país e no mundo. É apresentado também um novo sistema de planejamento denominado A Medical Image-based Graphical platfOrm (AMIGO). Esse software foi desenvolvido em parceria com o Instituto de Pesquisas Energéticas e Nucleares, a Universidade de São Paulo e a Universidade de Maastricht. A primeira versão do software foi desenvolvida para simular tratamentos braquiterápicos por meio de uma interface gráfica com recursos similares aos sistemas de planejamento comerciais. Uma nova versão está sendo desenvolvida para uso em teleterapia, como uma alternativa aos softwares comercias, e permitirá a análise de diversos detalhes do tratamento, além da validação dos cálculos realizados pelos sistemas comerciais.

    Palavras-Chave: algorithms; calculation methods; monte carlo method; phantoms; planning; radiation doses; radiotherapy

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  • IPEN-DOC 26505

    ALCANTARA, M.T.S. ; LINCOPAN, N.; SANTOS, P.M.; RAMIREZ, P.A.; BRANT, A.J.C. ; RIELLA, H.G. ; LUGAO, A.B. . Simultaneous hydrogel crosslinking and silver nanoparticle formation by using ionizing radiation to obtain antimicrobial hydrogels. Radiation Physics and Chemistry, v. 165, p. 1-9, 2019. DOI: 10.1016/j.radphyschem.2019.108369

    Observação: Referred to by Radiation Physics and Chemistry, v. 169, 2020. DOI: 10.1016/j.radphyschem.2020.108777 (em anexo)

    Abstract: Hydrogel dressings are crosslinked hydrophilic polymers able of swelling in presence of water and can be used in many different types of wound care. In turn, in wound care, silver has been used for a long time as an effective antimicrobial agent. Recent studies have demonstrated an increase of its antimicrobial action when it is used at nanometer scale, that is, as silver nanoparticles (AgNPs), which have anti-inflammatory effect on infected wounds, rashes, and mesh skin grafts. The objective of this work was to study hydrogel dressings containing AgNPs from silver nitrate, synthesized by radiation involving the formation of silver nanoparticles with simultaneous occurrence of crosslinking and sterilization of the polymer systems. One of the hydrogels was prepared with poly(N-vinyl-2- pyrrolidone) (PVP) and the other with poly(vinyl alcohol) (PVA) as main studied polymers. An aqueous solution of AgNO3 was added to both polymer systems separately. The AgNPs synthesis, polymer crosslinking and dressing sterilization were achieved simultaneously by irradiating the resultant solutions with gamma-rays from a 60Co source. Gel fraction, swelling in reverse osmosis water, SEM-EDS, UVvisible spectroscopy, and antimicrobial activity were performed and characterized. The obtained results showed that the dressings have a soft consistency, high degree of crosslinking and swelling, homogeneous distribution of AgNPs with peaks of plasmonic bands about 400 nm, but only PVP hydrogel showed antimicrobial properties to P. aeruginosa and normal S. aureus. Moreover, this hydrogel also showed antimicrobial properties to S. aureus strain multiresistant to penicillins, cephalosporins, carbapenems, sulfonamides, tetracyclines, quinolones, and aminoglycosides, whereas the PVA hydrogel showed antimicrobial properties to P. aeruginosa and bacteriostatic activity to S. aureus. The results suggest that both synthesized dressings have potential for use in wounds and burns infected with gram-positive and gram-negative bacteria.

    Palavras-Chave: hydrogels; silver; nanoparticles; ionizing radiations; antimicrobial agents; silver nitrates; wounds; antimitotic drugs; antipyretics; sintering; radiations

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  • IPEN-DOC 26504

    LEE, S.M. ; LAPA, N.S.; SABUNDJIAN, G. . Simulation of a severe accident at a typical PWR due to break of a hot leg ECCS injection line using MELCOR code. Brazilian Journal of Radiation Sciences, v. 7, n. 2B, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i2B.682

    Abstract: The aim of this work was to simulate a severe accident at a typical PWR, initiated with a break in Emergency Core Cooling System line of a hot leg, using the MELCOR code. The model of this typical PWR was elaborated by the Global Research for Safety and provided to the CNEN for independent analysis of the severe accidents at Angra 2, which is similar to this typical PWR. Although both of them are not identical, the results obtained of that typical PWR may be valuable because of the lack of officially published simulation of severe accident at Angra 2. Relevant parameters such as pressure, temperature and water level in various control volumes, after the break at the hot leg, were calculated as well as degree of core degradation and hydrogen production within the containment. The result obtained in this work could be considered satisfactory in the sense that the physical phenomena reproduced by the simulation were in general very reasonable, and most of the events occurred within acceptable time intervals. However, the uncertainty analysis was not carried out in this work. Furthermore, this scenario could be used as a base for the study of the effectiveness of some preventive or/and mitigating measures of Severe Accident Management by implementing each measure in this model.

    Palavras-Chave: gesellschaft fuer anlagen- und reaktorsicherheit; lbloca; m codes; pwr type reactors; reactor cores; boundary conditions; brazilian cnen; eccs; computerized simulation

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  • IPEN-DOC 26502

    ZAGATTO, V.A.B.; CREMA, E.; SHORTO, J.M.B. ; MORAIS, M.C.; LUBIAN, J.; ADDED, N.; SIMÕES, R.F.; MONTEIRO, D.S.; HUIZA, J.F.P.; PAES, B.; GOMES, P.R.S.. Scattering of 16,18O beams on 63,65Cu targets: a systematic study of different reaction channels. Physical Review C, v. 100, n. 4, p. 044602-1 - 044602-11, 2019. DOI: 10.1103/PhysRevC.100.044602

    Abstract: Precise quasielastic experimental excitation function for the 18O + 65Cu system has been measured and its barrier distribution has been derived. Several reaction channels have been observed on the experimental spectra, revealing the presence of two-neutron and α-stripping processes, as well as the proton pickup transfer, for which excitation functions were also measured. Extensive coupled channel and coupled reaction channel calculations have been performed to describe the experimental data. The inelastic couplings of target and projectile, and the ground state reorientation of the target, were important to the proper description of data. The transfer data were well described by calculations; however, it was shown that they almost do not affect the excitation function of 18O + 65Cu quasielastic scattering. Whenever possible, structure shell model calculations have been performed to obtain the spectroscopic amplitudes of projectile and target overlaps. The two-neutron and α-transfer reactions have been calculated considering the transferred particle as a cluster with spin 0.

    Palavras-Chave: excitation systems; inelastic scattering; nuclear reactions; copper 63 reactions; copper 65 reactions; oxygen 16 reactions; oxygen 18 reactions; beams

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  • IPEN-DOC 26501

    SOUPIONA, O.; SAMARAS, S.; ORTIZ-AMEZCUA, P.; BOCKMANN, C.; PAPAYANNIS, A.; MOREIRA, G.A. ; BENAVENT-OLTRA, J.A.; GUERRERO-RASCADO, J.L.; BEDOYA-VELASQUEZ, A.E.; OLMO, F.J.; ROMAN, R.; KOKKALIS, P.; MYLONAKI, M.; ALADOS-ARBOLEDAS, L.; PAPANIKOLAOU, C.A.; FOSKINIS, R.. Retrieval of optical and microphysical properties of transported Saharan dust over Athens and Granada based on multi-wavelength Raman lidar measurements: study of the mixing processes. Atmospheric Environment, v. 214, p. 1-15, 2019. DOI: 10.1016/j.atmosenv.2019.116824

    Abstract: In this paper we extract the aerosol microphysical properties for a collection of mineral dust cases measured by multi-wavelength depolarization Raman lidar systems located at the National Technical University of Athens (NTUA, Athens, Greece) and the Andalusian Institute for Earth System Research (IISTA-CEAMA, Granada, Spain). The lidar-based retrievals were carried out with the Spheroidal Inversion eXperiments software tool (SphInX) developed at the University of Potsdam (Germany). The software uses regularized inversion of a two-dimensional enhancement of the Mie model based on the spheroid-particle approximation with the aspect ratio determining the particle shape. The selection of the cases was based on the transport time from the source regions to the measuring sites. The aerosol optical depth as measured by AERONET ranged from 0.27 to 0.54 (at 500 nm) depending on the intensity of each event. Our analysis showed the hourly mean particle linear depolarization ratio and particle lidar ratio values at 532 nm ranging from 11 to 34% and from 42 to 79 sr respectively, depending on the mixing status, the corresponding air mass pathways and their transport time. Cases with shorter transport time showed good agreement in terms of the optical and SphInXretrieved microphysical properties between Athens and Granada providing a complex refractive index value equal to 1.4 + 0.004i. On the other hand, the results for cases with higher transport time deviated from the aforementioned ones as well as from each other, providing, in particular, an imaginary part of the refractive index ranging from 0.002 to 0.005. Reconstructions of two-dimensional shape-size distributions for each selected layer showed that the dominant effective particle shape was prolate with diverse spherical contributions. The retrieved volume concentrations reflect overall the intensity of the episodes.

    Palavras-Chave: aerosols; minerals; dusts; aerial monitoring; deserts; optical radar; depolarization; computer codes; aerosol monitoring

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  • IPEN-DOC 26497

    MADUAR, M.F. ; MAZZILLI, B.P. ; NISTI, M.B. . Radiation hazard indices in the application of phosphogypsum mixtures as a building material: proposal for a Brazilian regulation. Brazilian Journal of Radiation Sciences, v. 7, n. 3, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i3.839

    Abstract: Phosphogypsum (PG), a by-product from the phosphoric acid industry, is being worldwide stockpiled, posing environmental problems. Viability of the PG safe re-use in civil construction has been studied, as PG can contain natural radionuclides in significant concentrations. We propose a policy for using PG as a building material, limiting the total concentration of 226Ra plus 228Ra by mixing PG with natural gypsum. It was concluded that PG from the largest Brazilian deposits could be used without any dilution, when the sum of the activity concentrations of 226Ra and 228Ra does not exceed 150 Bq kg-1. For higher values, the approach is to mix PG with increasing amounts of natural gypsum, so that the final concentration does not exceed 1000 Bq kg-1. We show that PG re-use in such a way is feasible in terms of radiological protection and recommended to minimize PG piles environmental impact.

    Palavras-Chave: building materials; gypsum; natural radioactivity; radiation hazards; radiation protection; radium 226; radium 228; waste product utilization

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  • IPEN-DOC 26495

    MARIANO, DOUGLAS O.C.; PREZOTTO-NETO, JOSE P. ; SPENCER, PATRICK J. ; SCIANI, JULIANA M.; PIMENTA, DANIEL C.. Proteomic analysis of soluble proteins retrieved from Duttaphrynus melanostictus skin secretion by IEx-batch sample preparation. Journal of Proteomics, v. 209, p. 1-24, 2019. DOI: 10.1016/j.jprot.2019.103525

    Abstract: Amphibians display a toxic secretion that works as chemical defenses against predators and/or microorganisms that is stored in specialized glands located in the tegument. For some animals, such glands have accumulated in specific regions of the body and formed prominent structures known as macroglands. The Bufonidae family displays conspicuous macroglands in a post-orbital position, termed parotoids, which secretions are known to be extremely viscous and rich in alkaloids and steroids. Few proteins have been described in this material, though. Mainly, because of the difficulties to handle such biological matrix. In this context, we have performed a proteomic study on the parotoid macrogland secretion of the Asian bufonid Duttaphrynus melanostictus. By employing the Ion-Exchange (IEx)-batch chromatography (anionic, cationic and both) we obtained six fractions - bound and unbound – that were submitted to an in solution-trypsin digestion followed by LC-MS/MS. Proteins related to: antioxidant activity, binding processes (carbohydrate/lipid/protein), energy metabolism, hydrolases, lipid metabolism and membrane traffic were identified. Moreover, IEx was able to preserve the biological activity of the retrieved proteins (peptidasic). The current study increases the knowledge on the proteins present in the bufonids parotoid macrogland secretion, providing a better understanding of the physiological role played by such molecules. Significance: The current approach allowed a detailed proteomic analysis of the several proteins synthesized in the D. melanostictus parotoid macrogland (Bufonidae) that are secreted into the skins, but embedded within a complex viscous biological matrix. Moreover, our results aim to increase the knowledge on the biological role played by such proteins at the skin.

    Palavras-Chave: amphibians; skin; secretion; ion exchange chromatography; protein structure; structural chemical analysis; animal tissues; solubility; frogs

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  • IPEN-DOC 26494

    MARIANO, DOUGLAS O.C.; MESSIAS, MARCELA D.G. ; SPENCER, PATRICK J. ; PIMENTA, DANIEL C.. Protein identification from the parotoid macrogland secretion of Duttaphrynus melanostictus. Journal of Venomous Animals and Toxins including Tropical Diseases, v. 25, p. 1-12, 2019. DOI: 10.1590/1678-9199-JVATITD-2019-0029

    Abstract: Background: Bufonid parotoid macrogland secretion contains several low molecular mass molecules, such as alkaloids and steroids. Nevertheless, its protein content is poorly understood. Herein, we applied a sample preparation methodology that allows the analysis of viscous matrices in order to examine its proteins. Methods: Duttaphrynus melanostictus parotoid macrogland secretion was submitted to ion-exchange batch sample preparation, yielding two fractions: salt-displaced fraction and acid-displaced fraction. Each sample was then fractionated by anionic-exchange chromatography, followed by in-solution proteomic analysis. Results: Forty-two proteins could be identified, such as acyl-CoA-binding protein, alcohol dehydrogenase, calmodulin, galectin and histone. Moreover, de novo analyses yielded 153 peptides, whereas BLAST analyses corroborated some of the proteomicidentified proteins. Furthermore, the de novo peptide analyses indicate the presence of proteins related to apoptosis, cellular structure, catalysis and transport processes. Conclusions: Proper sample preparation allowed the proteomic and de novo identification of different proteins in the D. melanostictus parotoid macrogland secretion. These results may increase the knowledge about the universe of molecules that compose amphibian skin secretion, as well as to understand their biological/physiological role in the granular gland.

    Palavras-Chave: proteins; secretion; amphibians; frogs; glands; skin; protein structure; chromatography; spectroscopy

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  • IPEN-DOC 26493

    SILVA, M.V.S.; SANTO, A.M.E.; BALDOCHI, S.L. ; GONÇALVES, A.M.; EIRAS, J.A.; LENTE, M.H.. Production and characterization of (K Na)(Nb Cu)O3 crystal fibers grown by micro-pulling-down method. Ferroelectrics, v. 545, n. 1, SI, p. 89-96, 2019. DOI: 10.1080/00150193.2019.1621693

    Abstract: Cu-doped sodium potassium niobate single crystal fibers (KNN-Cu) were grown by the micro-pulling-down technique under different atmospheres, namely, argon, synthetic air and oxygen. The structural analysis revealed that all fibers were grown in the perovskite phase with no secondary phase. In comparison with the precursors powders, the results from EDX showed no significative chemical changes, suggesting that monocrystalline and stoichiometric KNN-Cu fibers were produced. The ferroelectric phase transitions characterized by thermal strain measurements corroborated this assumption. The dielectric results showed that the fibers produced under synthetic air presented the best results. Piezoresponse measurements revealed domains with typically orthorhombic symmetry morphology.

    Palavras-Chave: ferroelectric materials; sodium; potassium; niobates; monocrystals; crystal growth methods; piezoelectricity; crystal structure

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  • IPEN-DOC 26490

    SIQUEIRA, PAULO T.D. ; YORIYAZ, HELIO ; SHORTO, JULIAN M.B. ; CAVALIERI, TASSIO A. . Princípios e aplicações da terapia por captura de nêutrons por boro / Principles and applications of boron neutron capture therapy. Revista Brasileira de Física Médica, v. 13, n. 1, p. 116-121, 2019. DOI: 10.29384/rbfm.2019.v13.n1.p116-121

    Abstract: A terapia por captura de nêutrons (neutron capture therapy — NCT) é uma técnica radioterápica bimodal com princípios de funcionamento muito vantajosos para o tratamento de cânceres difusos. Contudo, apesar dessa vantagem conceitual e de sua primeira proposição já exceder 80 anos, essa técnica ainda não se encontra consolidada na comunidade clínica internacional como proposta terapêutica. Esse insucesso em seu estabelecimento não tem impedido que diversos grupos de pesquisa de diversos países do mundo invistam tempo e recursos em seu desenvolvimento. Neste texto apresentamos brevemente um histórico da NCT e dos principais desafios enfrentados pelos diversos grupos de pesquisas, uma comunidade de entusiastas da técnica, no seu desenvolvimento e na consolidação terapêutica da sua vertente mais estudada, a boron neutron capture therapy (BNCT). É apresentado também um resumo dos principais resultados alcançados com a técnica, além de um breve relato dos estudos realizados na instalação experimental de BNCT no Brasil.

    Palavras-Chave: boron; boron 10; brazilian cnen; carriers; dosimetry; gadolinium; neutron capture therapy; neutron sources; radiotherapy

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  • IPEN-DOC 26488

    PERINI, EFRAIN A. ; SKOPCHENKO, MIKHAIL; HONG, TRAN T.; HARIANTO, RAHMAT; MAITRE, ALEXIS; RODRIGUEZ, MAIDELYS R.R.; SANTOS, NATHALIA de O.; GUO, YINGLEI; QIN, XIANGYU; ZEITUNI, CARLOS A. ; STAROVOITOVA, VALERIIA N.. Pre-feasibility study for establishing radioisotope and radiopharmaceutical production facilities in developing countries. Current Radiopharmaceuticals, v. 12, n. 3, p. 187-200, 2019. DOI: 10.2174/1874471012666190328164253

    Abstract: Background: A significant number of developing countries have no facilities to produce medical radioisotopes and radiopharmaceuticals. Objective: In this paper we show that access to life-saving radioisotopes and radiopharmaceuticals and the geographical distribution of corresponding infrastructure is highly unbalanced worldwide. Methods: We discuss the main issues which need to be addressed in order to establish the production of radioisotopes and radiopharmaceuticals, which are especially important for developing countries as newcomers in the field. The data was gathered from several sources, including databases maintained by the International Atomic Energy Agency (IAEA), World Health Organization (WHO), and other international organizations; personal interactions with representatives in the nuclear medicine field from different regions of the world; and relevant literature. Results: Developing radioisotope and radiopharmaceutical production program and installing corresponding infrastructure requires significant investments, both man-power and financial. Support already exists to help developing countries establish their medical radioisotope production installations from several organizations, such as IAEA. Conclusion: This work clearly shows that access to life-saving radioisotopes and the geographical distribution of corresponding infrastructure is highly unbalanced. Technology transfer is important as it not only immediately benefits patients, but also provides employment, economic activity and general prosperity in the region to where the technology transfer is implemented.

    Palavras-Chave: radiopharmaceuticals; isotope production; feasibility studies; radioisotopes; developing countries; nuclear medicine; nuclear facilities; positron computed tomography; emission computed tomography

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  • IPEN-DOC 26487

    AZEVEDO, MARIANGELA de B.M. de ; MELO, VITOR H.S. ; SOARES, CARLOS R.J. ; GAMARRA, LIONEL F.; BARROS, CAIO H.N.; TASIC, LJUBICA. Poly(3-hydroxi-butyrate-co-3-hydroxy-valerate) (PHB-HV) microparticles loaded with holmium acetylacetonate as potential contrast agents for magnetic resonance images. International Journal of Nanomedicine, v. 14, p. 6869-6889, 2019. DOI: 10.2147/IJN.S191274

    Abstract: Introduction: Biodegradable polymers that contain radioactive isotopes such as Holmium 166 have potential applications as beta particle emitters in tumor tissues. Also, Ho(III) is paramagnetic, which makes it suitable as a contrast agent for magnetic resonance (MR) images. Methods: Holmium acetylacetonate (Ho(acac)3) loaded poly(3-hydroxy-butyrate-co-3- hydroxy-valerate) microspheres, with 5% or 8% of 3-hydroxy-valerate (HV), were prepared by emulsification/evaporation process within 20–53 μm size. Microspheres characterization was done using scanning electron microscopy, energy-dispersive X-ray, and infrared spectroscopies. The release of holmium(III) in sodium phosphate buffer (pH 7.4) was followed for 9 days with inductively coupled plasma. Finally, T2 and T2* magnetic resonance images (MRI) were acquired and compared with the MRI of the inclusion complex of holmium acetylacetonate in some β-cyclodextrins. Results: Holmium acetylacetonate loading, evaluated by thermogravimetry, was up to 20 times higher for copolymer with 5% of HV. It was shown that microspheres loaded with Ho(acac)3 exhibited an accumulation of Ho(III) on their surfaces but were stable over time, as no expressive release of holmium(III) was detected in 9-day exposition to sodium phosphate buffer. Holmium acetylacetonate in both microspheres or inclusion complexes was very efficient in obtaining T2 and T2* weighted images in magnetic resonance, thus, might be used as contrast agents. Conclusion: This is the first description of the use of inclusion complexes of holmium acetylacetonate in biodegradable polymers as contrast agents. New investigations are underway to evaluate the resistance of PHB-HV polymer microparticles to nuclear activation to assess their potential for use as radiopharmaceuticals for the treatment of liver cancer.

    Palavras-Chave: polymers; holmium; holmium 166; acetylacetone; contrast media; magnetic resonance; neoplasms; therapy; microspheres

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  • IPEN-DOC 26486

    IZIDORO, JULIANA de C. ; MIRANDA, CAIO ; CASTANHO, DAVI ; ROSSATI, CARLOS ; CAMPELLO, FELIPE ; GUILHEN, SABINE N. ; FUNGARO, DENISE A. ; WANG, SHAOBIN. Physical and chemical characteristics of feed coal and its by-products from a Brazilian thermoelectric power plant. Journal of Applied Materials and Technology, v. 1, n. 1, p. 1-14, 2019. DOI: 10.31258/Jamt.1.1.1-14

    Abstract: In this study, feed coal (FC) from the Figueira Thermoelectric Power Plant (FTPP), located in the state of Paraná (PR), Brazil was characterized by X-ray fluorescence (XRF), X-ray diffractometry (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), particle size distribution analysis by laser diffraction, loss of ignition (LOI), total carbon content (TC), pH and conductivity. FC-derived by-products (CCBs) collected at the FTPP were: bottom ash (BA), fly ash from cyclone filter (CA) and fly ash from bag filter (FA). In addition to the techniques used for feed coal characterization, CCBs were also characterized by total surface area (by using BET method), external surface area (by using laser diffraction), cation exchange capacity (CEC), bulk density, besides leaching and solubilization tests. FC sample contains 72.2% of volatile material, of which 55.3% is total carbon content. LOI, FTIR, TGA and TC analyzes corroborated with these results. The main crystalline phases in the FC sample were found to be quartz, kaolinite and pyrite. The elements As, Cr, Ni and Pb were encountered in the FC sample, indicating that the use of FTPP feed coal should be monitored due to the toxic potential of these elements. The three coal ashes were classified as class F according to ASTM and presented similar chemical composition, with total content of the main oxides (SiO2, Al2O3 and Fe2O3) above 72%. Ashes enrichment factor analysis (EF) showed that As, Zn and Pb concentrate mainly in fly ash from bag filter (FA), whereas the elements K and Mg presented higher enrichment in the bottom ash (BA) . All ashes presented quartz, mullite and magnetite as crystalline phases, as well as the same functional groups, related to the presence of humidity, organic matter and Si and Al compounds. XRD, XRF, TGA, FTIR, LOI and TC techniques were correlated and confirmed the obtained results. Total and external surface area values of CCBs were related to the total carbon content (TC), as well as to the results of particle size distribution and the scanning electron micrographs of the samples. On the other hand the CEC of the ashes showed relation with the particle size distribution and with the external surface area. Leaching and solubilization tests of CCBs showed that FA sample was considered hazardous and classified as class I waste, while CA and BA samples were considered non-hazardous and non-inert wastes and classified as class II-A. FA sample from Figueira power plant must be discarded only after treatment or a stringent disposal criterion must be followed to avoid contamination on site. In this work, feed coal sample was also compared to the CCBs samples generated from it. The results showed the differences between fuel and products through the different characterization techniques. In addition to contributing to the understanding of the relationship between coal and its combustion products, this work can also help to reduce the environmental impacts caused by the CCBs disposal, as well as can also be used to compare the characteristics of CCBs from FTPP with the new wastes that will be generated by the same thermal power plant that will be soon modernized.

    Palavras-Chave: thermal power plants; thermoelectricity; coal; materials; thermal analysis; chemical composition; combustion products; physical chemistry; brazil; electric power

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  • IPEN-DOC 26485

    BENTO, RODRIGO T. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Photocatalytic activity of undoped and sulfur-doped TiO2 films grown by MOCVD for water treatment under visible light. Journal of the European Ceramic Society, v. 39, n. 12, p. 3498-3504, 2019. DOI: 10.1016/j.jeurceramsoc.2019.02.046

    Abstract: Titanium dioxide ceramic coatings have been used as catalysts in green technologies for water treatment. However, without the presence of a dopant, its photocatalytic activity is limited to the ultraviolet radiation region. The photocatalytic activity and the structural characteristics of undoped and sulfur-doped TiO2 films grown at 400 °C by metallorganic chemical vapor deposition (MOCVD) were studied. The photocatalytic behavior of the films was evaluated by methyl orange dye degradation under visible light. The results suggested the substitution of Ti4+ cations by S6+ ions into TiO2 structure of the doped samples. SO4 2− groups were observed on the surface. S-TiO2 film exhibited good photocatalytic activity under visible light irradiation, and the luminous intensity strongly influences the photocatalytic behavior of the S-TiO2 films. The results supported the idea that the sulfur-doped TiO2 films grown by MOCVD may be promising catalysts for water treatment under sunlight or visible light bulbs.

    Palavras-Chave: titanium oxides; photocatalysis; ceramics; surface coating; sulfur; doped materials; chemical vapor deposition; dyes; hydrogen sulfates; water treatment

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  • IPEN-DOC 26483

    AMARAL-SANTOS, E.; JELINEK, A.R.; ALMEIDA-ABREU, P.A.; GENEZINI, F.A. . Phanerozoic cooling history of Archean/Paleoproterozoic basement in the southern Espinhaço Range, southeastern Brazil, through apatite fission-track analysis. Journal of South American Earth Sciences, v. 96, p. 1-13, 2019. DOI: 10.1016/j.jsames.2019.102352

    Abstract: Apatite fission track thermochronology of basement rocks from the southern Espinhaço Range and Quadrilátero Ferrífero in southeastern Brazil unravels the tectonic history of this portion of the Brazilian Shield. The study area encompasses an Archean and Paleoproterozoic granitoid-gneiss basement, in the southern border of the São Francisco Craton, and an Archean to Paleo-Mesoproterozoic sedimentary cover. Apatite fission track ages (AFT) vary from 187 ± 18 to 91.8 ± 7.3 Ma and horizontal confined track lengths vary from 9.62 ± 1.81 μm to 12.85 ± 1.35 μm. Thermal history modeling shows an accelerated cooling episode starting in the Upper Devonian to Early Permian. After this event, quiescence lasted from 115 to 170 Ma. Apatite samples lack evidence of far-field effects from rifting and opening of the South Atlantic Ocean, and also evidence from alkaline and basaltic magmatism emplacement during Mesozoic-Cenozoic. The AFT thermochronometer remained undisturbed during Transminas mafic dyke swarm intrusion. Finally, the last cooling event in the Espinhaço Range- Quadrilátero Ferrífero basement records ascension to surface temperatures due to epeirogeny after new configurations of the Nazca, South American and African plates. A climatic origin for the ascension is supported by accentuated erosion rates, even though a weathering-prone phase is registered in weathering profiles.

    Palavras-Chave: fission tracks; apatites; tectonics; geologic history; sedimentary rocks; brazil; soils

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  • IPEN-DOC 26482

    NANDENHA, J. ; PIASENTIN, R.M. ; SILVA, L.G.M. ; FONTES, E.H. ; NETO, A.O. ; SOUZA, R.F.B. de . Partial oxidation of methane and generation of electricity using a PEMFC. Ionics, v. 25, n. 10, p. 5077-5082, 2019. DOI: 10.1007/s11581-019-03186-z

    Abstract: The aim of this work was to produce methanol through partial oxidation of methane. The gas fed in a solid membrane reactor- PEM fuel cell type (H2/H2O2 + CH4) has been used for electrosynthesis of methanol at room temperature, with electricity cogeneration as a benefit. It was observed that the current density measured when injected CH4 in the cathode decreased about 45%. This occurs due to the conversion of methane inmethanol in some ranges of potentials. In the other hand, in lower ranges of cell potential, formaldehyde was found. In this work, methane was injected on the cathode together with H2O2 solution, where it was observed that the catalytic layer adsorbed CH4 and H2O2 in active sites, which produced OH− radicals that reacted with the hydrocarbon.

    Palavras-Chave: proton exchange membrane fuel cells; membrane transport; methane; electrodes; synthesis; electrochemistry; electric generators; methanol

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  • IPEN-DOC 26481

    ARAUJO, JESUINA C.S.; OTON, LAIS F.; OLIVEIRA, ALCINEIA C.; LANG, ROSSANO; OTUBO, LARISSA ; BUENO, JOSE M.C.. On the role of size controlled Pt particles in nanostructured Pt-containing Al2O3 catalysts for partial oxidation of methane. International Journal of Hydrogen Energy, v. 44, n. 50, p. 27329-27342, 2019. DOI: 10.1016/j.ijhydene.2019.08.176

    Abstract: The effect of the Pt loadings and particles sizes on the stability of Pt(x wt%)/Al2O3 catalysts were investigated in the partial oxidation of methane (POM) reaction. The Al2O3 support was prepared by sol-gel method and different Pt loadings, varying from 0.5 to 2.0 wt% were incorporated to alumina through the incipient wetness impregnation method. The physicochemical features of the catalysts were determined by XRD, ICP-OES, Nitrogen-sorption, UVeVisible, H2-TPR, CO-DRIFTS, SEM-EDS, XPS and HRTEM techniques. The metal dispersion was evaluated in the cyclohexane dehydrogenation reaction. Lower Pt loadings resulted in well dispersed Pto nanoparticles with an enhanced activity in cyclohexane dehydrogenation and POM reactions. With increasing Pt loading to 2.0 wt%, the Pt nanoparticles of the Pt(2.0 wt%)/Al2O3 showed a methane conversion of 63% in 24 h of time on stream, and the catalyst was very selective to H2 and CO. Based on the HRTEM, XPS and Raman spectroscopy techniques, an increment in the Pt loadings evidenced an enrichment of Pto clusters on the surface, however, no heavy carbon deposits formation was observed.

    Palavras-Chave: methane; oxidation; aluminium oxides; platinum; nanostructures; catalysts; carbon

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  • IPEN-DOC 26480

    ASSUNÇÃO, ISRAEL P.; CARNEIRO NETO, ALBANO N.; MOURA JUNIOR, RENALDO T.; PEDROSO, CASSIO C.S.; SILVA, IVAN G.N.; FELINTO, MARIA C.F.C. ; TEOTONIO, ERCULES E.S.; MALTA, OSCAR L.; BRITO, HERMI F.. Odd-even effect on luminescence properties of europium aliphatic dicarboxylate complexes. ChemPhysChem, v. 20, n. 15, p. 1931-1940, 2019. DOI: 10.1002/cphc.201900603

    Abstract: The odd–even effect in luminescent [Eu2(L)3(H2O)x]·y(H2O) complexes with aliphatic dicarboxylate ligands (L: OXA, MAL, SUC, GLU, ADP, PIM, SUB, AZL, SEB, UND, and DOD, where x=2–6 and y=0–4), prepared by the precipitation method, was observed for the first time in lanthanide compounds. The final dehydration temperatures of the Eu3+ complexes show a zigzag pattern as a function of the carbon chain length of the dicarboxylate ligands, leading to the so-called odd-even effect. The FTIR data confirm the ligand–metal coordination via the mixed mode of bridge–chelate coordination, except for the Eu3+-oxalate complex. XRD results indicate that the highly crystalline materials belong to the monoclinic system. The odd– even effect on the 4 f–4 f luminescence intensity parameters (Ω2 and Ω4) is explained by using an extension of the dynamic coupling mechanism, herein named the ghost-atom model. In this method, the long-range polarizabilities (a*) were simulated by a ghost atom located at the middle of each ligand chain. The values of a* were estimated using the localized molecular orbital approach. The emission intrinsic quantum yield (QLn Ln) of the Eu3+ complexes also presented an the odd-even effect, successfully explained in terms of the zigzag behavior shown by the Ω2 and Ω4 intensity parameters. Luminescence quenching due to water molecules in the first coordination sphere is also discussed and rationalized.

    Palavras-Chave: luminescence; europium; dicarboxylic acids; atoms; odd-even nuclei; photoluminescence

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  • IPEN-DOC 26479

    BRAGA, THAIS L.; PINTO, SUYENE R.; REIS, SARA R.R. dos; PORTILHO, FILIPE L.; BARROS, ALINE O. da S. de; BERNARDES, EMERSON S. ; SANTOS, SOFIA N. dos ; ALENCAR, LUCIANA M.R.; RICCI-JUNIOR, EDUARDO; SANTOS-OLIVEIRA, RALPH. Octreotide nanoparticles showed affinity for in vivo MIA Paca-2 inducted pancreas ductal adenocarcinoma mimicking pancreatic polypeptide-secreting tumor of the distal pancreas (PPoma). Pharmaceutical Research, v. 36, n. 10, p. 1-8, 2019. DOI: 10.1007/s11095-019-2678-4

    Abstract: Purpose Pancreatic Polypeptide-secreting tumor of the distal pancreas (PPoma) is a rare, difficult and indolent type of cancer with a survival rate of 5-year in only 10% of all cases. The PPoma is classified as a neuroendocrine tumor (NET) not functioning that overexpresses SSTR 2 (somatostatin receptor subtype 2). Thus, in order to improve the diagnosis of this type of tumor, we developed nanoparticulate drug carriers based on poly-lactic acid (PLA) polymer loaded with octreotide and radiolabeled with Technetium-99 m (99mTc). Methods PLA/PVA octreotide nanoparticles were developed by double-emulsion technique. These nanoparticles were characterized by Atomic Force Microscopy (AFM) and Dynamic Light Scattering (DLS) and radiolabeled with 99mTc by the direct via forming 99mTc-PLA/PVA octreotide nanoparticles. The safety of these nanosystems was evaluated by the MTT cell toxicity assay and their in vivo biodistribution was evaluated in xenografted inducted animals. Results The results showed that a 189 nm sized nanoparticle were formed with a PDI of 0,097, corroborating the monodispersive behavior. These nanoparticles were successfully radiolabeled with 99mTc showing uptake by the inducted tumor. The MTT assay corroborated the safety of the nanosystem for the cells. Conclusion The results support the use of this nanosystem (99mTc-PLA/PVA octreotide nanoparticles) as imaging agent for PPoma.

    Palavras-Chave: nanoparticles; radiopharmaceuticals; pancreas; carcinomas; images; image processing; light scattering; tumor cells; cell cultures

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  • IPEN-DOC 26478

    CABRAL, FERNANDA V. ; PELEGRINO, MILENA T.; SAUTER, ISMAEL P.; SEABRA, AMEDEA B.; CORTEZ, MAURO; RIBEIRO, MARTHA S. . Nitric oxide-loaded chitosan nanoparticles as an innovative antileishmanial platform. Nitric Oxide, v. 93, p. 25-33, 2019. DOI: 10.1016/j.niox.2019.09.007

    Abstract: Leishmaniasis is a neglected tropical disease that demands for new therapeutic strategies due to adverse side effects and resistance development promoted by current drugs. Nitric oxide (NO)-donors show potential to kill Leishmania spp. but their use is limited because of their instability. In this work, we synthesize, characterize, and encapsulate S-nitroso-mercaptosuccinic acid into chitosan nanoparticles (NONPs) and investigate their activity on promastigotes and intracellular amastigotes of Leishmania (Leishmania) amazonensis. Cytotoxicity on macrophages was also evaluated. We verified that NONPs reduced both forms of the parasite in a single treatment. We also noticed reduction of parasitophorous vacuoles as an evidence of inhibition of parasite growth and resolution of infection. No substantial cytotoxicity was detected on macrophages. NONPs were able to provide a sustained parasite killing for both L. (L.) amazonensis infective stages with no toxicity on macrophages, representing a promising nanoplatform for cutaneous leishmaniasis.

    Palavras-Chave: chitin; nanoparticles; nitric oxide; protozoa; parasitic diseases; bioluminescence; fluorescence; macrophages; antimitotic drugs; antimicrobial agents

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  • IPEN-DOC 26477

    SPATAFORA, A.; CAPPUZZELLO, F.; CARBONE, D.; CAVALLARO, M.; LAY, J.A.; ACOSTA, L.; AGODI, C.; BONANNO, D.; BONGIOVANNI, D.; BOZTOSUN, I.; BRISCHETTO, G.A.; BURRELLO, S.; CALABRESE, S.; CALVO, D.; LOMELI, E.R.C.; CIRALDO, I.; COLONNA, M.; DELAUNAY, F.; DESHMUKH, N.; FERREIRA, J.L.; FINOCCHIARO, P.; FISICHELLA, M.; FOTI, A.; GALLO, G.; HACISALIHOGLU, A.; IAZZI, F.; LANZALONE, G.; LENSKE, H.; LINARES, R.; PRESTI, D.L.; LUBIAN, J.; MORALLES, M. ; MUOIO, A.; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; REITO, S.; RUSSO, G.; SANTAGATI, G.; SGOUROS, O.; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V.A.B.. 20Ne + 76Ge elastic and inelastic scattering at 306 MeV. Physical Review C, v. 100, n. 3, p. 034620-1 - 034620-8, 2019. DOI: 10.1103/PhysRevC.100.034620

    Abstract: Background: Double charge exchange (DCE) nuclear reactions have recently attracted much interest as tools to provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double-β decay. In this framework, a good description of the reaction mechanism and a complete knowledge of the initial and final-state interactions are mandatory. Presently, not enough is known about the details of the optical potentials and nuclear response to isospin operators for many of the projectile-target systems proposed for future DCE studies. Among these, the 20Ne + 76Ge DCE reaction is particularly relevant due to its connection with 76Ge double-β decay. Purpose: We intend to characterize the initial-state interaction for the 20Ne + 76Ge reactions at 306 MeV bombarding energy and determine the optical potential and the role of the couplings between elastic channel and inelastic transitions to the first low-lying excited states. Methods: We determine the experimental elastic and inelastic scattering cross-section angular distributions, compare the theoretical predictions by adopting different models of optical potentials with the experimental data, and evaluate the coupling effect through the comparison of the distorted-wave Born approximation calculations with the coupled channels ones. Results: Optical models fail to describe the elastic angular distribution above the grazing angle (≈9.4◦). A correction in the geometry to effectively account for deformation of the involved nuclear systems improves the agreement up to about 14◦. Coupled channels effects are crucial to obtain good agreement at large angles in the elastic scattering cross section. Conclusions: The analysis of elastic and inelastic scattering data turned out to be a powerful tool to explore the initial and final-state interactions in heavy-ion nuclear reactions at high transferred momenta.

    Palavras-Chave: neon 20; germanium 76; isotopes; charge-exchange reactions; elastic scattering; inelastic scattering; decay; scattering amplitudes

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  • IPEN-DOC 26476

    ABESSA, D.M.S.; RACHID, B.R.F.; ZARONI, L.P.; GASPARRO, M.R.; PINTO, Y.A.; BICEGO, M.C.; HORTELLANI, M.A. ; SARKIS, J.E.S. ; MUNIZ, P.; MOREIRA, L.B.; SOUSA, E.C.P.M.. Natural factors and chemical contamination control the structure of macrobenthic communities in the Santos Estuarine System (SP, Brazil). Community Ecology, v. 20, n. 2, p. 121-137, 2019. DOI: 10.1556/168.2019.20.2.3

    Abstract: The Santos Estuarine System (SES) is a complex of bays, islands, estuarine channels, and rivers located on the Southeast coast of Brazil, in which multiple contaminant sources are situated in close proximity to mangroves and other protected areas. In this study, the composition and structure of the macrobenthic communities of SES were described and ninetynine species were identified, with the predominance of polychaetes and bivalve mollusks. The benthic assemblages also showed strong signs of stress, as indicated by the low abundance, richness and diversity, and the dominance of opportunistic species. Integrated analysis including sediment characteristics related to natural and anthropogenic factors (e.g., sediment chemistry, and toxicity) indicated that benthic fauna from the inner portions of the SES and vicinities of the SSOS diffusers as Santos Bay were affected. Some locations at the mouths of Santos and Sao Vicente estuaries exhibited moderate disturbance. In other sites from the mouth of São Vicente and Bertioga channels, and Santos Bay, the benthic fauna were considered not degraded. Our results suggest that a combination of both environmental factors and contaminants were responsible for the benthic community structure.

    Palavras-Chave: aquatic organisms; benthos; water pollution; estuaries; aquatic ecosystems; pollution sources; chemical effluents; chemical wastes; environmental impacts; sediments; grain size; metals; concentration ratio; brazil

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  • IPEN-DOC 26475

    ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; SALVADOR, V.L.R. ; SATO, I.M. ; MENDONÇA, R.Z.; WEN, F.H.; SIMONS, M.S.. Multielemental analyses of Lonomia obliqua (Lepidoptera, Saturniidae) caterpillar using EDXRF and INAA techniques. X-Ray Spectrometry, v. 48, n. 5, SI, p. 465-475, 2019. DOI: 10.1002/xrs.3076

    Abstract: In this study, multielemental analysis of Lonomia obliqua (Lepidoptera, Saturniidae) caterpillar was performed using energy dispersive X‐ray fluorescence and instrumental neutron activation analysis techniques. This caterpillar is poisonous and has the ability to cause fatal hemorrhagic effects in humans after contact. The need of this study is related to morphological changes (mainly size and color) observed in some caterpillars used for preparation of antilonomic serum (antivenom). The samples were classified as healthy (caterpillars of control) and unhealthy (caterpillars visibly modified). The XRF measurements were performed in an energy dispersive X‐ray fluorescence spectrometer and the instrumental neutron activation analysis using the IEAR1 nuclear reactor at IPEN. The results show significant differences for several elements (mainly, P, Cl, Ca, Ti, Mn, Fe, Ni, and Zn) in unhealthy caterpillars that can affect the development of this species as well as the quality and yield of the antivenom. Furthermore, its elemental characterization contributes for the understanding the potential pharmacological (procoagulant and antithrombotic) in the prevention of life‐threatening blood clots.

    Palavras-Chave: insects; x-ray fluorescence analysis; neutron activation analysis; multi-element analysis; venoms; toxicity; pharmacology; brazil; anticoagulants; blood coagulation

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  • IPEN-DOC 26474

    LANGE, CAMILA N.; MONTEIRO, LUCILENA R. ; FREIRE, BRUNA M.; FRANCO, DANIEL F.; SOUZA, ROGERIO O. de; FERREIRA, CECILIA S. dos R.; SILVA, JULIO J.C. da; BATISTA, BRUNO L.. Mineral profile exploratory analysis for rice grains traceability. Food Chemistry, v. 300, p. 1-10, 2019. DOI: 10.1016/j.foodchem.2019.125145

    Abstract: Rice geographical traceability requires analytical procedures and data evaluation capable of linking its composition to the producing area. In this work, major and trace elements in soil and rice grains and husk from 9 cities and 17 producers were evaluated. Arsenic species were measured solely in rice grains. The rice mineral profile evaluated by principal component analysis allowed the identification of controlling variables and origin fingerprints. Vectors controlling data variability were linked to the geographical area, to crop management, producers and in a lower extent to soil composition. Elemental discrimination through 3D models was proposed. Arsenic species in the grains and elemental husk composition were decisive to achieve the required discrimination. Rice discrimination was obtained by cities, producers and varieties. The present work model was compared with others from similar studies.

    Palavras-Chave: rice; cereals; arsenic; minerals; geographical variations; agriculture; brazil; soils; toxic materials

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  • IPEN-DOC 26473

    SILVA, R.; ARANA, C.; MALAFAIA, A.M. de S.; MENDES FILHO, A.A.; PASCAL, C.; OTUBO, J. ; SORDI, V.L.; ROVERE, C.A.D.. Microstructure and surface oxidation behavior of an austenitic Fe-Mn-Si-Cr-Ni-Co shape memory stainless steel at 800 °C in air. Corrosion Science, v. 158, p. 1-10, 2019. DOI: 10.1016/j.corsci.2019.108103

    Abstract: In the present research, the microstructure and oxidation behavior of an Fe-8.26Mn-5.25Si-12.80Cr-5.81Ni- 11.84Co shape memory stainless steel (SMSS) was studied at 800 °C in air for up to 120 h. Phase changes and oxidation mechanism were discussed based on microscopy analyses, thermogravimetric measurements and thermodynamic simulations. The results show that oxidation exposure promotes the formation of the σ, χ and ferrite phases in the metallic substrate. The oxidation behavior follows a parabolic law, with the kinetics of oxidation being controlled by the Mn2O3 oxide growth in the first hours, and by Mn3O4 and MnCr2O4 spinel growth after 24 h of exposure.

    Palavras-Chave: microstructure; oxidation; stainless steels; shape memory effect; temperature range 0400-1000 k; scanning electron microscopy; transmission electron microscopy; optical microscopy; thermodynamics; simulation; thermal gravimetric analysis

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  • IPEN-DOC 26472

    MIRANDA. RANULFO B. de P.; BORGES, ROGER; MARCHI, JULIANA; LIMA, NELSON B. de ; CESAR, PAULO F.. Microstructure and flexural strength of the Y:TZP/BG composite. International Journal of Applied Ceramic Technology, v. 16, n. 5, SI, p. 1979-1988, 2019. DOI: 10.1111/ijac.13306

    Abstract: The addition of bioactive glasses to a Y:TZP matrix represents a feasible alternative to provide bioactivity to this material and optimize osseointegration. This work evaluated the effect of the BG concentration (0 and 10 wt%) and the sintering temperature (1200°C and 1300°C) on the microstructure, relative density, and flexural strength of the composite Y:TZP/BG. The Y:TZP and Y:TZP/BG powders were uniaxially pressed and sintered at 1200°C or 1300°C for 1 h. The microstructure was characterized by X‐ray diffraction analysis, scanning electron microscopy, and energy‐dispersive X‐ray Spectroscopy. Relative density was calculated from density values obtained using the Archimedes’ principle. For the flexural strength, specimens (n = 6) were fractured in a biaxial flexural setup using a piston‐on‐three‐balls fixture in a universal testing machine. Bioactivity test was performed in simulated body fluid solution. The results suggested that BG addition decreased the grain size of the composite, increased porosity and caused a significant decrease in the relative density and flexural strength. Crystalline phases of calcium stabilized cubic zirconia and sodium zirconium silicate were formed after the addition of BG. Finally, it was concluded that composite specimens sintered at 1300°C showed the highest density values and larger grains compared to those sintered at 1200°C.

    Palavras-Chave: glass; biological materials; microstructure; dentin; implants; yttrium; polycrystals; zirconium; sintering; ceramics; powders

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  • IPEN-DOC 26471

    BELLEZZO, MURILLO ; BAEZA, JOSE A.; VONCKEN, ROBERT; RENIERS, BRIGITTE; VERHAEGEN, FRANK; FONSECA, GABRIEL P.. Mechanical evaluation of the Bravos afterloader system for HDR brachytherapy. Brachytherapy, v. 18, n. 6, p. 852-862, 2019. DOI: 10.1016/j.brachy.2019.06.005

    Abstract: PURPOSE: The Bravos afterloader system was released by Varian Medical Systems in October of 2018 for high-dose-rate brachytherapy with 192Ir sources, containing new features such as the CamScale (a new device for daily quality assurance and system recalibration), channel length verification, and different settings for rigid and flexible applicators. This study mechanically evaluated the Bravos system precision and accuracy for clinically relevant scenarios, using dummy sources. METHODS AND MATERIALS: The system was evaluated after three sets of experiments: (1) The CamScale was used to verify inter- and intra-channel dwelling variability and system calibration; (2) A high-speed camera was used to verify the source simulation cable movement inside a transparent quality assurance device, where dwell positions, dwell times, transit times, speed profiles, and accelerations were measured; (3) The source movement inside clinical applicators was captured with an imaging panel while being exposed to an external kV source. Measured and planned dwell positions and times were compared. RESULTS: Maximum deviations between planned and measured dwell positions and times for the source cable were 0.4 mm for the CamScale measurements and 0.07 seconds for the high-speed camera measurements. Mean dwell position deviations inside clinical applicators were below 1.2 mm for all applicators except the ring that required an offset correction of 1 mm to achieve a mean deviation of 0.4 mm. CONCLUSIONS: Features of the Bravos afterloader system provide a robust and precise treatment delivery. All measurements were within manufacturer specifications.

    Palavras-Chave: afterloading; irradiation procedures; brachytherapy; calibration; dose rates; dosimetry; radiation dose distributions

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  • IPEN-DOC 26470

    INVERNIZZI, BRUNO P. ; SILVA, LEANDRO G. ; NEVES, MAURICIO D.M. das . Mechanical properties for circumferential welding applied to UNS S32750 Super Duplex Stainless Steel using the GMAW process with CMT control. Engineering, v. 11, n. 9, p. 576-591, 2019. DOI: 10.4236/eng.2019.119040

    Abstract: Super Duplex Stainless Steel has been studied for oil and gas industry applications since the 90 s, but their welding always is a technical issue. Then different methods were developed to meet all requirements presents in ASME standards, where most of are applied for lower production, when compared to other materials such carbon steel. This study accomplished circumferential welding experiments in base material (BM)—UNS S32750 Super Duplex Stainless Steel with a thickness of 3.68 mm. Welding was performed using GMAW (Gas Metal Arc Welding) process with CMT (Cold Metal Transfer) control and the aid of a Motoman robot and a turntable device, which were used to ensure the accurate positioning of the torch and that the welding has been fully implemented in the 1 G position, respectively. This process achieves higher production in relation other welding process usually applied for this material class. The joints which presented adequate dimensional results were, then, subjected to tensile and hardness Vickers tests. To avoid the lack of penetration problem, the welding was performed using the CMT process combined with pulsed arc, thus, resulting in full penetration and improved surface finish. The results have shown that the CMT procedure, combined with pulsed arc, led to an adequate superficial finishing, mechanical properties and corrosion resistance in accomplishment with the requirements presented in applicable standards.

    Palavras-Chave: corrosion resistant alloys; electric arcs; heat exchangers; mechanical properties; nuclear energy; pipes; stainless steels; vickers hardness; welded joints; welding; microstructure

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  • IPEN-DOC 26469

    FONSECA, T.C.F.; ANTUNES, P.C.G. ; BELO, M.C.L.; BASTOS, F.; CAMPOS, T.P.; GERALDO, J.M.; MENDES, A.M.; MENDES, B.M.; PAIXÃO, L.; SANTANA, P.C.; SENIWAL, B.; SQUAIR, P.L.; YORIYAZ, H. . MCMEG: intercomparison exercise on prostate radiotherapy dose assessment. Radiation Physics and Chemistry, v. 167, p. 1-7, 2020. DOI: 10.1016/j.radphyschem.2019.04.045

    Abstract: The improvement of the Monte Carlo (MC) community skills on computational simulations in Medical Physics is crucial to the field of radiotherapy as well as radiology. The Monte Carlo Modelling Expert Group (MCMEG) is an expert network specialized in MC radiation transport modelling and simulation applied to the radiation protection and dosimetry research fields. The MCMEG addressed a multigroup dosimetric intercomparison exercise for modelling and simulating a case of prostate radiation therapy (RT) protocol. This intercomparison was launched in order to obtain the dose distribution in the prostate target volume and in the neighboring organs. Dose assessments were achieved by using TLDs. A protocol using two pair of parallel-opposed fields were planned and performed with Alderson-Rando Pelvic Phantom. The assessed organs at risk were the urinary bladder, rectum and right and left femur heads. The RT simulations were performed using the MCNPx, MCNP6 and egs++ and BEAMnrc/DOSXYZnrc modules of EGSnrc Monte Carlo codes. The dose to the target volume, mean doses and standard deviation in the organs at risk, and dose volume data were computed. A comparison between the simulated results and the experimental values obtained from TLD measurements was made. In some cases the results obtained using MC simulations showed large deviations in comparison to the results obtained from the TLD measurements and these variations can be explained by the difficulties in the modelling of the geometry, selection of MC parameters required for the simulations and the statistical errors and inaccuracies in experimental measurements. Even though, the exercise has been a great opportunity for the MC groups to learn and share the main difficulties found during the modelling and the analysis of the results. Concerned to the obtained variations, the MCMEG team consider that this was expected for the level of complexity of the exercise and must be studied by the MC groups.

    Palavras-Chave: monte carlo method; simulation; radiotherapy; prostate; irradiation; formation damage; phantoms; interlaboratory comparisons; radiation doses; therapy; radiology

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  • IPEN-DOC 26468

    SOUZA, LUIZA F.; SANTOS, WILLIAM S. ; BELINATO, WALMIR; SILVA, ROGERIO M.V.; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.. Mass energy absorption coefficients and energy responses of magnesium tetraborate dosimeters for 0.02 MeV to 20 MeV photons using Monte Carlo simulations. Applied Radiation and Isotopes, v. 148, p. 232-239, 2019. DOI: 10.1016/j.apradiso.2019.04.015

    Abstract: Thermoluminescence dosimeters containing boron, such as magnesium tetraborate (MgB4O7), are of interest because of their very high sensitivity, near tissue-equivalent absorption coefficients, low cost, easy handling, and very large linearity range for absorbed dose. Another important parameter that should be considered when working with thermoluminescent dosimeter (TLD) is the mass energy absorption coefficient (μen/ρ), which is a close approximation to the energy available for production of chemical, biological and other effects associated with exposure to ionizing radiation, therefore important in estimating dose in medical and health physics. In this study the mass energy absorption coefficients and energy responses of undoped and some doped magnesium tetraborates were calculated by Monte Carlo N-particle transport code for a range of photon energies between 20 keV and 20 MeV. The calculated parameters for MgB4O7, MgB4O7:Dy and MgB4O7:Dy,Li were evaluated in comparison with standard TLDs as Al2O3:C and TLD-100 (LiF: Mg, Ti) and ICRU tissue data. The influence of the dopant concentration in the MgB4O7 matrix on the energy dependence of TLD was also investigated. The analyses indicated a good agreement between the simulations and theoretical calculations. The μen/ρ and energy dependence of the materials are higher in the low energy range (E < 100 keV), which is related to the high probability of interaction between radiation and matter due to photoelectric absorption. With regard to the influence of dysprosium concentration in the MgB4O7 matrix an increase in the energy dependence of MgB4O7 for higher concentrations of dopants was observed in the low energy range.

    Palavras-Chave: absorbed radiation doses; borates; boron; computerized simulation; concentration ratio; doped materials; energy absorption; energy dependence; icru; ionizing radiations; kev range; lithium fluorides; magnesium; magnesium compounds; mev range; monte carlo method; radiation protection; sensitivity; thermoluminescent dosemeters

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  • IPEN-DOC 26467

    DUARTE, LUIS F. de A.; MORENO, JULIAN B.; CATHARINO, MARILIA G.M. ; MOREIRA, EDSON G. ; TROMBINI, CHIARA; PEREIRA, CAMILO D.S.. Mangrove metal pollution induces biological tolerance to Cd on a crab sentinel species subpopulation. Science of the Total Environment, v. 687, p. 768-779, 2019. DOI: 10.1016/j.scitotenv.2019.06.039

    Abstract: Metals are persistent pollutants, able to accumulate in the biota andmagnify in trophicweb. In the specific case of cadmium contamination, it has been the subject of considerable interest in recent years because of its biological effects and it is one ofmajor pollutant in estuarine areas. Ucides cordatus is considered amangrove local sentinel crab species in Brazil and there are previous studies reporting crab subpopulations living frompristine to heavily metal impacted areas in São Paulo coast (Southeastern Brazil). Taking into account the background knowledge about these subpopulations, we proposed the hypothesis that crabs from a highly polluted mangrove (Cubatão - CUB) have developed biological tolerance to cadmium compared to animals from an Environmental Protected Area (Jureia - JUR). Aiming to verify this hypothesis, we have investigated total bioaccumulation and subcellular partition of Cd, besides biomarkers' responses during a long-termexposure bioassay (28 days, withweekly sampling) using a supposedly safe Cd concentration (0.0022 mg L−1). Specimens from the pristine area (JUR) accumulated higher total Cd, as such as in its biologically active form in gills. Animals living in the polluted site (CUB) presented higher amounts of Cd in themainly detoxifying tissue (hepatopancreas), which could be considered a pathway leading to tolerance for this metal. Multivariate analysis indicated that bioaccumulation (active, detoxified and total Cd) is linked to geno-cytotoxic damages. CUB subpopulationwas considered more tolerant since it presented proportionally less damage and more capacity to allocate Cd in themain detoxifying forms and tissues.

    Palavras-Chave: metals; pollutants; pollution sources; toxicity; mangroves; subcellular distribution; biological markers; crabs; environmental impacts; cadmium; ecological concentration; concentration ratio; brazil

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  • IPEN-DOC 26466

    BOSCH-SANTOS, B. ; NASCIMENTO, N.M. ; SAIKI, M. ; CORREA, E.L. ; SALES, T.S.N. ; PEREIRA, L.F.D. ; CABRERA-PASCA, G.A.; SAXENA, R.N. ; SCHELL, J.; CARBONARI, A.W. . Magnetic field at Ce impurities in La sites of La0.5Ba0.5MnO3 double perovskites. AIP Advances, v. 9, n. 3, p. 035245-1 - 035245-5, 2019. DOI: 10.1063/1.5080094

    Abstract: Due to its rich variety of electromagnetic properties, such as a colossal magnetoresistance, charge and orbital ordering, and metal-insulator transition, the magnetic behavior in La0.5Ba0.5MnO3 double perovskite compounds has been investigated by several techniques, however more experimental data, especially from atomic resolution techniques, are still necessary to understand such complex behavior. In this paper, we have used a nuclear and short-range technique, the Perturbed Angular Correlation (PAC) spectroscopy, to investigate the magnetic hyperfine interaction at the 140Ce and 111Cd probe nuclei as impurities occupying La sites. This double perovskite samples were synthesized by Sol- Gel route. The crystal structure was determined by X-ray diffraction and the analyses showed that this method produced perovskite oxides with cubic structure in Pm-3m space group and the homogeneity was determined by Transmission Electron Microscopy (TEM). The local properties investigated by PAC spectroscopy revealed a ferromagnetic transition temperature above 300 K and a pure antiferromagnetic interaction below 100 K. Moreover, it also indicates an anomalous behavior of the temperature dependence of magnetic hyperfine field at La sites measured with 140Ce probe nuclei, which can be ascribed to the contribution of 4f band of Ce to Magnetic Hyperfine Field (Bhf) at low temperatures due to the increase in its localized character.

    Palavras-Chave: magnetic fields; spectroscopy; perturbed angular correlation; transmission electron microscopy; perovskite; cerium alloys; impurities; polycrystals; lanthanum

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  • IPEN-DOC 26465

    SOUZA, LUIZA F.; NOVAIS, ANDREA L.F.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.. Luminescent properties of MgB4O7:Ce,Li to be applied in radiation dosimetry. Radiation Physics and Chemistry, v. 164, p. 1-6, 2019. DOI: 10.1016/j.radphyschem.2019.108353

    Abstract: MgB4O7 is a promising matrix host for use in radiation dosimetry due to its low effective atomic number (Zeff=8.2). The present work aims to investigate dosimetric and luminescent properties of the MgB4O7:Ce0,5%,Li0.5%, produced through solid-state synthesis, using the optically stimulated luminescence (OSL) technique. The first part of this work discusses the luminescent aspects of this phosphor, such as thermoluminescent emission spectra, photoluminescence emission, lifetime of emission centers and the effect of different lithium concentrations as co-dopant. In the second part, the basic OSL properties were evaluated, including dose-response curve, minimum detectable dose (MDD), step annealing, and best bleaching set-up for reuse of MgB4O7:Ce0,5%Li0.5% composites. The photoluminescence and thermoluminescence emission spectra of the composites present an emission peak at UV-VIS range centered around 370 nm, which is the most suitable for OSL dosimetry; this emission is related to Ce3+ electronic transitions and has a luminescence center lifetime of 0.003 ms. From the step-annealing analyses, it can be seen that the OSL emission is related to different depth trap centers in the band gap. The OSL dose-response curve is linear from 0.1 Gy to 100 Gy, with a MDD around 1 mGy. These properties make this material a strong candidate for different applications in radiation dosimetry field.

    Palavras-Chave: dosimetry; luminescence; thermoluminescent dosimetry; photoluminescence; emission spectra; magnesium; borates; doped materials

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  • IPEN-DOC 26462

    LANGE, C.N.; FLUES, M. ; HIROMOTO, G. ; BOSCOV, M.E.G.; CAMARGO, I.M.C. . Long-term leaching of As, Cd, Mo, Pb, and Zn from coal fly ash in column test. Environmental Monitoring and Assessment, v. 191, n. 10, p. 1-12, 2019. DOI: 10.1007/s10661-019-7798-0

    Abstract: Globally, millions of tons of coal fly ash (CFA) are generated per year, and the majority of this material is usually stored in stock piles or landfills, and in a long-term, it can be an environmental hazard if rainwater infiltrates the ashes. Long-term leaching studies of Brazilian ashes are scarce. The purpose of this study was to evaluate arsenic, cadmium, molybdenum, lead, and zinc leaching behavior from a Brazilian CFA by a column experiment designed to simulate field conditions: slightly acid rain considering seasonality of precipitation and temperature for a long-term leaching period (336 days). All elements were leached from CFA, except lead. Elements leaching behavior was influenced by leaching time, leaching volume, and temperature. Higher leachability of As and Cd from CFA during warm and wet season was observed. Results indicate a potential risk to soil and groundwater, since ashes are usually stored in uncovered fields on power plants vicinity.

    Palavras-Chave: fly ash; coal; testing; leaching; trace amounts; elements; hazardous materials; toxic materials; arsenic; cadmium; molybdenum; lead; zinc; brazil

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  • IPEN-DOC 26461

    EL HAJJ, THAMMIRIS M.; GANDOLLA, MAURO P.A.; SILVA, PAULO S.C. da ; TORQUATO, HENRIQUE; DELBONI JUNIOR, HOMERO. Long-term prediction of non-processed waste radioactivity of a niobium mine in Brazil. Journal of Sustainable Mining, v. 18, n. 3, p. 142-149, 2019. DOI: 10.1016/j.jsm.2019.04.003

    Abstract: This work analyzed samples from a niobium mine in Brazil which produces massive quantities of non-processed waste (NPW) each year. Due to concerns about the environmental impact of stacking up this material in the longterm, investigations have had been made to evaluate its re-use options. Nevertheless, there are no regulations from the Brazilian National Commission of Nuclear Energy about commercializing this sub-product which has highly variable radiological activity because of the different lithologies present in the mine. Thus, the activity concentrations of 238U, 232Th, 226Ra, 228Ra, 228Th and 40K of the naturally radioactive ore (53 boreholes) and of the NPW (8 samples) were measured. Radiological hazard indices, radium equivalent, internal and external hazard and their equivalent doses were also calculated. Moreover, the X-ray diffraction, depth and coordinates of all samples were used to identify radioactive prone areas in the mine. For the NPW samples, the activity concentrations (in Bq/kg) were, on average, 64.9 of 238U, 104.8 of 226Ra, 1813.9 of 232Th, 1292.2 of 228Th, 1224.3 of 228Ra and 1184.2 of 40K. The analysis showed great variability between samples and the results can be used to evaluate possible uses such as building materials or foundation for roadbeds.

    Palavras-Chave: naturally occurring radioactive materials; niobium ores; radiation hazards; mining; radioactive waste processing; waste processing; mines; brazil; hazardous materials

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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

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A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.