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  • IPEN-DOC 26661

    CORREIA, M.M.; CHAMMAS, M.C.; ZAVARIZ, J.D.; ARATA, A. ; MARTINS, L.C.; MARUI, S.; PEREIRA, L.A.A.. Evaluation of the effects of chronic occupational exposure to metallic mercury on the thyroid parenchyma and hormonal function. International Archives of Occupational and Environmental Health, v. 93, n. 4, p. 491-502, 2020. DOI: 10.1007/s00420-019-01499-0

    Abstract: Introduction Experiments in animals exposed to mercury (Hg) in different chemical states have shown thyroid parenchymal and hormone alterations. However, these experiments did not allow the establishment of dose–response curves or provide an understanding of whether these Hg effects on the thyroid parenchyma occur in humans. Objective To evaluate the association between chronic occupational exposure to metallic Hg and alterations in thyroid hormones and gland parenchyma 14 years after the last exposure. Methods A cross-sectional study including 55 males exposed in the past to metallic Hg and 55 non-exposed males, paired by age, was conducted in the Hospital das Clínicas (Brazil) from 2016 to 2017. Serum concentrations of total and free triiodothyronine (TT3 and FT3), free thyroxine (FT4), thyrotropin (TSH), reverse T3 (RT3), selenium and antithyroid antibody titers were obtained. The Hg and iodine concentrations were measured in urine. The thyroid parenchyma was evaluated by B-mode ultrasonography with Doppler. The nodules with aspects suspicious for malignancy were submitted to aspiration puncture with a thin needle, and the cytology assessment was classified by the Bethesda system. The t test or Mann–Whitney test, Chi-square test and Spearman correlation were used to compare the exposed and non-exposed groups and examine the relationships between the variables. Univariate and multivariate logistic regression models were used to trace determinants of the risk of thyroid hormone alteration. Statistical significance was defined by p < 0.05. Results The urinary Hg average was significantly higher in the exposed group than in the non-exposed group (p < 0.01). The mean TSH serum concentration in the exposed group was higher, with a statistically significant difference between the groups (p = 0.03). Serum concentrations of TSH exceeded the normality limit (4.20 μIU/ml) in 13 exposed individuals (27.3%) and 4 non-exposed individuals (7.3%), with a statistically significant association between the hormonal increase and exposure to Hg (p = 0.02). In the logistic regression model, exposure to Hg (yes or no) showed an odds ratio = 4.86 associated with an increase of TSH above the normal limit (p = 0.04). The serum concentrations of RT3 showed a statistically borderline difference between the groups (p = 0.06). There was no statistically significant difference between the mean TT3, FT3 and FT4 serum concentrations in the Hg-exposed group compared to the non-exposed group. The proportions of the echogenicity alterations were higher in the exposed group compared to the non-exposed group (27.3% versus 9.1%; p = 0.03). Papillary carcinomas were documented in three exposed individuals and one non-exposed individual. A follicular carcinoma was recorded in one non-exposed individual. Conclusions Due to the higher serum TSH concentration and the prevalence of parenchymal alterations in the Hg-exposed group, even after cessation of exposure, it is recommended that the thyroid status of exposed workers be followed for a long period.

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  • IPEN-DOC 26459

    SAUEIA, CATIA H.R. ; NISTI, MARCELO B. ; SILVA, PAULO S.C. da ; OLIVEIRA, JONATHAN P. de ; MAZZILLI, BARBARA P. . Lixiviation of rare earth elements in tropical soils amended with phosphogypsum. International Journal of Environmental Analytical Chemistry, v. 100, n. 6, p. 675-685, 2020. DOI: 10.1080/03067319.2019.1638918

    Abstract: In Brazil, the main producers of phosphate fertilisers are responsible for the production of approximately 12 million tons of phosphogypsum (PG) per year. This phosphogypsum has been used for many years in agriculture as a soil amendment. For its safe long-term application, it is necessary to characterise the impurities present in phosphogypsum and to study the leaching or dissemination of such impurities to waters or other ecosystem compartments. This paper aims to evaluate the availability of Rare Earth Elements (REEs): La, Ce, Nd, Sm, Eu, Tb and Lu. The technique used for the determination of the elements of interest in the soil, soil mixed with PG, PG and leachate was the instrumental neutron activation analysis. For this purpose, an experiment was carried out, in which columns filled with sandy and clay Brazilian typical soils mixed with phosphogypsum were percolated with water, to achieve a mild extraction of these elements. The results showed that the ƩREE in PG was in the order of 7,600 mg kg−1 while in the leachate, the sum was in the order of 100 μg L−1 results obtained for the available fraction obtained was below 1%, giving evidence that although the REEs are present in the PG in higher concentrations, they are not available to the water. It can be concluded that the addition of PG to the soils does not contribute to a significant enhancement of the REEs in water.

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  • IPEN-DOC 25762

    BARTOLOMEI, SUELLEN S. ; SANTANA, JULYANA G. ; DIAZ, FRANCISCO R.V.; KAVAKLI, PINAR A.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B. . Investigation of the effect of titanium dioxide and clay grafted with glycidyl methacrylate by gamma radiation on the properties of EVA flexible films. Radiation Physics and Chemistry, v. 169, p. 1-9, 2020. DOI: 10.1016/j.radphyschem.2018.08.022

    Abstract: Many studies report that nanocomposites obtained by dispersion of a small amount nanofiller into the polymer have remarkable improvements achieved in the mechanical and physical properties. However, in order to achieve this great improvement in properties, it is necessary that the nanofillers be dispersed homogeneously into the polymeric matrix. Often this dispersion is difficult to achieve due to the high interfacial energy of the nanoparticles present. This study reports the effect of gamma irradiation induced graft of glycidyl methacrylate (GMA) onto the surface of TiO2 and Clay nanofillers to improve their dispersion into the EVA matrix. The physical and mechanical properties of Ethylene-vinyl acetate copolymer (EVA) flexible films with these nanoparticles were studied. EVA nanocomposite with adding of the different amount of TiO2 and modified montmorillonite clay grafted and un-grafted with glycidyl methacrylate (GMA) using gamma irradiation have been prepared by melt extrusion. The nanocomposite flexible films were produced using a flat die extrusion process. The PGMA-grafted nanofillers were characterized by XRD and TEM analysis. The flexible films were characterized by Tensile tests, ATR–FTIR, UV–VIS, XRD, TG, and FE-SEM analysis to understand the nature of the interaction between the nanofillers and EVA matrix. The results showed that the addition of PGMA-grafted TiO2 and Clay nanofillers into EVA matrix improved the bonding between the nanofillers and matrix. It was also found that the PGMA-grafted nanofillers could be well dispersed into an EVA matrix in contrast to that of un-grafted. The tensile strength and modulus of the resulting EVA/TiO2-PGMA enhanced in comparison to that of un-grafted TiO2. The EVA/Clay-PGMA had slightly decreased tensile strength comparable to that of EVA/Clay but had considerably improved elastic modulus. In addition, the flexible films based on TiO2 exhibited high UV–Vis light absorption with energy gap shifted to the visible region. The results demonstrated that TiO2 and Clay nanofillers grafted with GMA by gamma radiation can be used to prepare EVA flexible films with improved bonding between the nanofillers and matrix and, consequently, enhanced properties for food and cosmetic packaging application.

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  • IPEN-DOC 25091

    FAZOLIN, GABRIELA N. ; VARCA, GUSTAVO H.C. ; KADLUBOWSKI, SLAWOMIR; SOWINSKI, SEBASTIAN; LUGAO, ADEMAR B. . The effects of radiation and experimental conditions over papain nanoparticle formation: towards a new generation synthesis. Radiation Physics and Chemistry, v. 169, p. 1-8, 2020. DOI: 10.1016/j.radphyschem.2018.08.033

    Abstract: Papain is a natural enzyme extracted from the fruit of Carica papaya Linnaeus, successfully applied in the pharmaceutical area as a drug carrier and debridement agent for wounds. In recent studies papain nanoparticles were synthesized and crosslinked with the use of ionizing radiation in the search for biopharmaceutical advantages as well as the development of bioactive nanocarriers. This study addresses the effects of buffer molarity and irradiation conditions on papain nanoparticles formation. Nanoparticles were synthesized on ice bath using ethanol (20%, v/v) as a cosolvent and crosslinked by gamma radiation using a 60Co source. Experimental variables included the synthesis in deionized water and in 1, 10, 25 and 50mM phosphate buffer, under different temperatures of −20 °C, 0 °C and 20 °C before and throughout the irradiation period, and using radiation dose rates of 0.8, 2, 5 and 10 kGy h−1 to reach the dose of 10 kGy. Proteolytic activity was quantified using Nα- benzoyl-DL-arginine-p-nitroanilide hydrochloride. Nanoparticle size and crosslinking by means of bityrosine were evaluated by dynamic light scattering and fluorescence measurements, respectively. Buffer molarity and radiation dose rate were identified to influence bityrosine formation and proteolytic activity without impacting nanoparticle size. Variations in temperature impacted bityrosine formation exclusively. Optimized conditions for papain nanoparticle synthesis were achieved using 50mM phosphate buffer at the dose rate of 5 kGy h−1 and temperature of 0 °C throughout the process.

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  • IPEN-DOC 26851

    MADI, LILIAN L.N. ; SORDI, GIAN-MARIA A.A. ; ARAUJO, EDMIR N. de. Nuclear state liability for damage resulting from nuclear activities. RAP Conference Proceedings, v. 4, p. 61-66, 2019. DOI: 10.37392/RapProc.2019.13

    Abstract: Much has already been seen in the world regarding the damage that may result from an accident in nuclear power plants. In the event of an accident that causes effective damage, either to the environment or to the population, both the Brazilian and foreign standards predict liability for remedying. The Brazilian Federal Constitution of 1988 determines the competence of the Union to operate nuclear services and installations, being State monopoly activities related to nuclear material and its derivatives. Besides that, FC/88 attributed liability stricto sensu for nuclear damage. The Vienna Convention on Civil Liability for nuclear damage, dated May 21, 1993, which was promulgated in Brazil by Decree No. 911/1993, provides that the operator is responsible for nuclear damages, in the case of Brazil, the operator is the State entity (Federal Autarchy) responsible for the operation. Thus, in cases of nuclear damage, the State should be held liable objectively. And here issues begin to arise such as: Is the State always responsible? Is there any possibility of exclusion of the State’s liability? This paper aims to analyze the constitutional text and the infra-constitutional rules in an attempt to answer these and other questions without, however, intending to exhaust the subject.

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  • IPEN-DOC 26850

    PEREIRA, MARIA da C.C. ; MADI FILHO, TUFIC ; BERRETTA, JOSE R. ; TOMAZ, LUCAS F. ; MADI, MIRIAM N. . Optical properties and radiation response of Li ion-doped CsI scintillator crystal. RAP Conference Proceedings, v. 4, p. 131-135, 2019. DOI: 10.37392/RapProc.2019.26

    Abstract: Scintillators are materials that convert the energy of ionizing radiation into a flash of light. Due to the existence of different types of scintillators, they are classified into three groups according to their physicochemical characteristics, namely, inorganic, organic and gaseous scintillators. Among the inorganic crystals, the most frequently used as scintillator consist of alkali metals, in particular alkaline iodides. Scintillation materials have many applications, for instance in medical imaging, security, physics, biology, non-destructive inspection and medicine. In this study, lithium doped CsI scintillator crystals were grown using the vertical Bridgman technique. The concentration of the lithium doping element (Li) studied was 10-4 M to 10-1 M. Analyses were carried out to evaluate the developed scintillators with regard to luminescence emission and optical transmittance. The luminescence emission spectra of these crystals were measured with a monochromator for gamma radiation from 137Cs source excitation. The determination of the dopant distribution along the crystalline axis allowed the identification of the region with Li concentration uniformity, which is the region of the crystalline volume indicated for use as a radiation detector. The crystals were excited with neutron radiation from AmBe source, with the energy range of 1 MeV to 12 MeV. As neutron sources also generate gamma radiation, which can interfere with the measurement, it is necessary that the detector be able to discriminate the presence of such radiation. Accordingly, experiments were performed using gamma radiation in the energy range of 59 keV to 1333 keV in order to verify the ability of the detector to discriminate the presence of different types of radiation.

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  • IPEN-DOC 26849

    MADI FILHO, TUFIC ; PEREIRA, MARIA da C.C. ; BERRETTA, JOSE R. ; TOMAZ, LUCAS F. ; MADI, MIRIAM N. . Study and development of neutron detectors using doped CsI crystals. RAP Conference Proceedings, v. 4, p. 117-121, 2019. DOI: 10.37392/RapProc.2019.23

    Abstract: The development of new radiation detectors using scintillation crystals, which increase response speed, dose and energy accuracy and, at the same time, the feasibility of simplifying and reducing costs in the production process are always necessary. In the CTR-IPEN laboratory, pure and doped CsI crystals were grown using the Bridgman technique. This work shows the obtained results using a doped CsI scintillator with the converters: Br, Pb, Tl, Li as alpha, beta, gamma and neutron detectors.

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  • IPEN-DOC 26742

    CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J.I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; CHAVEZ LOMELI, E.R.; COLONNA, M.; D’AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKH, N.; FARIA, P.N. de; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J.L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FLORES, A.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; GONGORA, B.; HACISALIHOGLU, A.; HAZAR, S.; HUERTA, A.; KOTILA, J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LA VIA, F.; LAY, J. A.; LENSKE, H.; LINARES, R.; LONGHITANO, F.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MARTINEZ, S.; MAS, J.; MEDINA, N.H.; MENDES, D.R.; MEREU, P.; MORALLES, M. ; OLIVEIRA, J.R.B.; ORDONEZ, C.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; REZA, G.; RIES, P.; RIFUGGIATO, D.; RODRIGUES, M.R.D.; RUSSO, A.D.; RUSSO, G.; SANDOVAL, S.; SANTOPINTO, E.; SANTOS, R.B.B.; SGOUROS, O.; SILVEIRA, M.A.G. da; SOLAKCI, S.O.; SOULIOTIS, G.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VSEVOLODOVNA, R.I.M.; VARGAS, H.; VEGA, G.; WANG, J.S.; WERNER, V.; YANG, Y.Y.; YILDIRIN, A.; ZAGATTO, V.A.B.. The NUMEN Project @ LNS: status and perspectives. Il Nuovo Cimento C, v. 42, n. 2-3, p. 1-7, 2019. DOI: 10.1393/ncc/i2019-19057-2

    Abstract: The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular attention is given to the (18O,18Ne) and (20Ne,20O) reactions as tools for β+β+ and β − β − decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models will be developed in order to extract the nuclear structure information from the measured cross sections.

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  • IPEN-DOC 26741

    LINO, JULIANA dos S. ; AQUINO, AFONSO R. de . Index of contaminated areas in São Paulo city, Brazil. WIT Transactions on Ecology and the Environment, v. 238, p. 199-208, 2019. DOI: 10.2495/SC190181

    Abstract: Environment contamination is a problem that most countries need to deal with in fields such as urban planning, public health, and availability of natural resources. Contaminated land, inside this topic, is a critical issue to discuss in the metropolis. Old areas have housed industrial activities, gas stations, and irregular waste disposal, can have the presence of toxic substances in the soil, underground, and in groundwater too, and this could lodge risk and a difficulty to change their land use and occupation, frequent in the dynamics of the societies. It is quite essential to create tools to handle this question, acknowledging the situation, and understanding how to achieve sustainable urban planning. Considering the existence of contaminated sites on the city and managing this, while The Sustainable Development Goals, as the Sustainable Cities and Communities, for instance, are applying. In this research, an index was developed of contaminated areas for the city of São Paulo, Brazil. The index was aimed to demonstrate in which districts are concentrated the contaminated sites and comprehend how the contamination it was spread at the city. The territorial unit used to divide the town was the district. The results indicated that the main contamination is concentrated near the downtown area and in older industrial districts. This data can be useful to define strategies on urban planning, because it can suggest which region is more indicated, or not, to receive different enterprises, around the city, like residential, commercial. Furthermore, the index can help to define what areas could need more specific environmental investigation and analysis to ensure the sustainability of the city and the citizens’ safety.

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  • IPEN-DOC 26739

    ENOKIHARA, C.T. ; SCHULTZ-GUTTLER, R.A.; RELA, P.R. . Gamma radiation of quartz from Entre Rios (SC) and Quaraí (RS). Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-12, 2019. DOI: 10.15392/bjrs.v7i2A.634

    Abstract: The availability of gamma ray irradiators in Brazil increased the possibilities of the treatment of gemstones for color enhancement. One of the minerals with very high potential for these treatments is the quartz, a very widespread mineral with many colored commercial varieties. There is a specific variety of quartz in nature, showing a green color that may be produced artificially, by gamma radiation (60Co). In Brazil, the widely scattered geode occurrence from Quaraí, at Brazil southernmost location up to Uberlandia, in Minas Gerais, is one of these events. Quartz from these occurrences have been formed by strong hydrothermal activities. Hence, many quartz crystals showed a very fast growth occurrence, facilitating the formation of consequent defects and the uptake of water under the form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work, the material analyzed is from hydrothermal regimes located near the towns Entre Rios and Quaraí. To characterize these materials, analyses have been made by ICP, NAA, electron microscopy, water loss techniques plus UV-VIS and NIR-FTIR spectroscopic measurements. Silanol complexes have been found by radiation, due to gamma rays forming the color center NBOHC (Non-Bonding Oxygen Hole Center), showing absorption between 590 to 620 nm and leaving a transmission window at about 550nm, responsible for the green color. The spectroscopic water determination showed less molecular water (up to 2300 ppm, per weight), probably due to remaining silanol complexes. The water content, with up to 3200 ppm by weight, exceeds the amount of charge balancing cations (Fe, Al, Li).

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  • IPEN-DOC 26738

    GLICKER, HAYLEY S.; LAWLER, MICHAEL J.; ORTEGA, JOHN; SA, SUZANE S. de; MARTIN, SCOT T.; ARTAXO, PAULO; BUSTILLOS, OSCAR V. ; SOUZA, RODRIGO de; TOTA, JULIO; CARLTON, ANNMARIE; SMITH, JAMES N.. Chemical composition of ultrafine aerosol particles in central Amazonia during the wet season. Atmospheric Chemistry and Physics, v. 19, n. 20, p. 13053-13066, 2019. DOI: 10.5194/acp-19-13053-2019

    Abstract: Central Amazonia serves as an ideal location to study atmospheric particle formation, since it often represents nearly natural, pre-industrial conditions but can also experience periods of anthropogenic influence due to the presence of emissions from large metropolitan areas like Manaus, Brazil. Ultrafine (sub-100 nm diameter) particles are often observed in this region, although new particle formation events seldom occur near the ground despite being readily observed in other forested regions with similar emissions of volatile organic compounds (VOCs). This study focuses on identifying the chemical composition of ultrafine particles as a means of determining the chemical species and mechanisms that may be responsible for new particle formation and growth in the region. These measurements were performed during the wet season as part of the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/ 5) field campaign at a site located 70 km southwest of Manaus. A thermal desorption chemical ionization mass spectrometer (TDCIMS) characterized the most abundant compounds detected in ultrafine particles. Two time periods representing distinct influences on aerosol composition, which we label as “anthropogenic” and “background” periods, were studied as part of a larger 10 d period of analysis. Higher particle number concentrations were measured during the anthropogenic period, and modeled back-trajectory frequencies indicate transport of emissions from the Manaus metropolitan area. During the background period there were much lower number concentrations, and back-trajectory frequencies showed that air masses arrived at the site predominantly from the forested regions to the north and northeast. TDCIMS-measured constituents also show distinct differences between the two observational periods. Although bisulfate was detected in particles throughout the 10 d period, the anthropogenic period had higher levels of particulate bisulfate overall. Ammonium and trimethyl ammonium were positively correlated with bisulfate. The background period had distinct diurnal patterns of particulate cyanate and acetate, while oxalate remained relatively constant during the 10 d period. 3-Methylfuran, a thermal decomposition product of a particulate-phase isoprene epoxydiol (IEPOX), was the dominant species measured in the positive-ion mode. Principal component analysis (PCA) was performed on the TDCIMS-measured ion abundance and aerosol mass spectrometer (AMS) mass concentration data. Two different hierarchical clusters representing unique influences arise: one comprising ultrafine particulate acetate, hydrogen oxalate, cyanate, trimethyl ammonium and 3-methylfuran and another made up of ultrafine particulate bisulfate, chloride, ammonium and potassium. A third cluster separated AMS-measured species from the two TDCIMS-derived clusters, indicating different sources or processes in ultrafine aerosol particle formation compared to larger submicron-sized particles.

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  • IPEN-DOC 26688

    BARCESSAT, ANA R. ; GURGEL-JUAREZ, NALIA C.; WETTER, NIKLAUS U. . Vital tooth bleaching using different techniques: a clinical evaluation. Future Dental Journal, v. xxx, n. xxx, p. xxx-xxx, 2019. DOI: 10.1016/j.fdj.2018.11.003

    Abstract: Objectives: This clinical trial aimed to evaluate dental color stabilization after different bleaching techniques. Methods: Four dental bleaching techniques were tested in 60 healthy volunteers aged from 25 to 35 years randomly assigned to four groups. Group 1 (G1): conventional in-office bleaching using 35% hydrogen peroxide. Group 2 (G2): in-office application of 3% hydrogen peroxide followed by in-office bleaching using 35% hydrogen peroxide. Group 3 (G3): in-office application of 3% hydrogen peroxide and activation with a light emitting diode (LED) lamp. Group 4 (G4): at-home bleaching using 10% carbamide peroxide. The color of canines and incisors was scored using a digital spectrophotometer to analyze lightness, chroma and hue. Results: All groups resulted in shade change. Lightness increased in all groups with no statistical difference among groups 60 days after finishing the treatment regardless of the technique used (p > 0.05). Differences were found in a short-term evaluation between some groups (p < 0.05). Chroma showed no statistical differences for central incisors after bleaching (p > 0.05). Analyzing canines, G4 showed higher chroma compared to G1 (p < 0.05) and G2 (p < 0.05). For hue, only G2 behaved differently for canines and incisors (p < 0.05). In other groups, hue scores decreased after bleaching. Conclusions: All techniques improved lightness. The addition of 3% hydrogen peroxide to conventional in-office whitening only increased appointment time, but no further benefits were noticed. Clinical relevance: This study is important to help clinicians deciding which is the most suitable dental bleaching for each patient in the current high aesthetic demanding world.

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  • IPEN-DOC 25904

    MEDEIROS, I.M.M.A. ; ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; MEDEIROS, J.A.G.. Sodium analysis in sweeteners by neutron activation analyses technique. Journal of Physics: Conference Series, v. 1291, p. 1-3, 2019. DOI: 10.1088/1742-6596/1291/1/012021

    Abstract: Evaluation of Sodium in sweeteners is important in nutritional investigations and for consumers: excessive sodium consumption is one of the major risk factors, responsible for hypertension and cardiovascular diseases. In this study, twelve brands acquired in markets of São Paulo city were analysed by Instrumental Neutron Activation Analyses technique (INAA). The aim was to verify compliance with ANVISA recommendation in relation to sodium level. The results were compared with the amounts recommended and with the tolerable intake limit (< 0.4 g/kg). The sodium concentration in sweeteners samples showed low content for most of the brands. The results shown that for the general population, it is not risk.

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  • IPEN-DOC 25903

    ZAHN, G.S. ; GENEZINI, F.A. ; RIBEIRO JUNIOR, I. . AnalisaCAEN, a simple software suite to reduce and analyze coincidence data collected using CAEN v1724 digitizer. Journal of Physics: Conference Series, v. 1291, p. 1-3, 2019. DOI: 10.1088/1742-6596/1291/1/012044

    Abstract: In this work a small software suite for the reduction and analysis of coincidence data collected using CAEN’s proprietary software was developed. These software check the output files for coincidences, generate a single list mode file with the coincident events, build histograms for each input, plus a time difference histogram and a 2-detector data matrix, perform time gates and allows for the subtraction of accidental coincidences, and perform energy gating on the final data matrices, generating histograms with the gated spectra. Moreover, the suite has an integrator that guides the user through all the required steps.

    Palavras-Chave: programming languages; computer codes; data processing; digital systems; digitizers; coincidence methods

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  • IPEN-DOC 25902

    ZAHN, G.S. ; GENEZINI, F.A. ; MORALLES, M. ; SIQUEIRA, P.T.D. ; MEDINA, N.H.; AGUIAR, V.A.P.; MACCHIONE, E.L.A.; ADDED, N.; SILVEIRA, M.A.G. da. A proposal to study long-lived isotopes produced by thermal neutron irradiation of digital devices. Journal of Physics: Conference Series, v. 1291, p. 1-3, 2019. DOI: 10.1088/1742-6596/1291/1/012020

    Abstract: In this work, we present a facility to study errors in digital devices exposed to thermal neutrons from a beam hole in the IEA-R1 nuclear reactor, as well as the long-lived isotopes produced in the irradiation of digital electronic devices under a slow neutron field. Preliminary results obtained with the analysis of a 28nm SRAM-based Xilinx Zynq-7000 FPGA are presented.

    Palavras-Chave: isotopes; reactors; digital systems; equipment; neutrons; radiations; iear-1 reactor; electronic equipment; beam holes; thermal neutrons; ionizing radiations

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  • IPEN-DOC 25901

    MIURA, V.M. ; ZAMBONI, C.B. ; TASSO, O.G.; LEWGOY, H.R. ; JESUS, K.A.; SILVA, R.Y.R.. Investigation of ions in human whole saliva by analytic techniques. Journal of Physics: Conference Series, v. 1291, p. 1-4, 2019. DOI: 10.1088/1742-6596/1291/1/012026

    Abstract: In this study, ions of clinical relevance in non-stimulated human whole saliva obtained from healthy subject’s donors (adults and children) at São Paulo city (Brazil), were investigated. The Instrument Neutron Activation Analysis (INAA) and Energy Dispersive X-Ray Fluorescence (EDXRF) techniques were used. The comparison concentration between adults and children for Cl, K, Ca and Fe showed significant differences for all elements, emphasizing the need of adopting different reference values.

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  • IPEN-DOC 25900

    GIOVANNI, D.N.S. ; ALMEIDA, M.R. ; ZAMBONI, C.B. ; METAIRON, S. ; BALDUINO, K.N. ; SUZUKI, M.F. ; BUENO JUNIOR, C.R.. Ions concentration in blood samples of SJL/J dystrophic mice strains using X-ray fluorescence spectrometry. Journal of Physics: Conference Series, v. 1291, p. 1-4, 2019. DOI: 10.1088/1742-6596/1291/1/012023

    Abstract: Star This study proposes an investigation of ions in whole blood of the dystrophic animal model SJL/J (mice strain with dysferlin protein deficiency) and in the control group (C57BL/6J) using the Energy Dispersive X-ray Fluorescence (EDXRF) spectrometry technique. The comparison between control and dystrophic mice results shown an increase in blood for P, S, K and Fe (p < 0.05) while a decrease in Ca (p < 0.05). This elemental analysis will contribute to evaluate the best diagnostic, care and treatment procedures, for the Progressive Muscular Dystrophy.

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  • IPEN-DOC 25899

    ALMEIDA, M.R. ; ZAMBONI, C.B. ; GIOVANNI, D.N.S. ; AZEVEDO, M.R.A.. Sulfur status in judo athletes by XRF. Journal of Physics: Conference Series, v. 1291, p. 1-4, 2019. DOI: 10.1088/1742-6596/1291/1/012011

    Abstract: The human biomonitoring, measurement of chemical and/or their metabolites in human fluids, is an important tool for assessing the health condition of subjects, included athletes. In this study, sulfur levels were investigated in blood of judo athletes using Energy Dispersive X-ray Fluorescence (EDXRF) technique. Twenty athletes participated of this study. Two groups of athletes were selected: judo with a balanced diet with multivitamin/mineral supplements consumption and judo with diet not controlled. These data were compared with the control group (subjects of the same age but not involved with physical activities). There was a significant increase of S levels in athletes with diet not controlled. These data can be useful to a well-planned nutritional proposition that can contribute to better performance of athletes.

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  • IPEN-DOC 26718

    JACOVONE, RAYNARA M.S. ; SOARES, JAQUELINE J.S. ; SOUSA, THAINA S. ; SILVA, FLAVIA R.O. ; GARCIA, RAFAEL H.L. ; NGUYEN, HANG N.; RODRIGUES, DEBORA F.; SAKATA, SOLANGE K. . Antibacterial activity of silver/reduced graphene oxide nanocomposite synthesized by sustainable process. Energy, Ecology and Environment, v. 4, n. 6, p. 318-324, 2019. DOI: 10.1007/s40974-019-00136-3

    Abstract: Traditional methods to incorporate metals into graphene oxide (GO) usually require toxic reagents or high temperatures. This study proposes an innovative and sustainable method to incorporate silver (Ag) into graphene oxide using electron beam and evaluate its antibacterial activities. The method is based on green synthesis, without toxic reagents or hazardous wastes, and can be carried out at room temperature, in short reaction times. To synthesize the Ag/rGO nanocomposite, a water/isopropanol solution with dispersed graphene oxide and silver nitrate was submitted to a dose range from 150 to 400 kGy. The product was characterized by thermogravimetry analysis, X-ray diffraction and transmission electron microscopy. The antibacterial activity of Ag/rGO was observed against Gram-negative Escherichia coli by plate count method and atomic force microscopy. The results showed that concentrations as low as 100 lg/mL of produced Ag/rGO were enough to inactivate the cells.

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  • IPEN-DOC 26451

    MACHADO, JOÃO P.S.L.; JELINEK, ANDREA R.; BICCA, MARCOS M.; STEPHENSON, RANDELL; GENEZINI, FREDERICO A. . West Gondwana orogenies and Pangaea break-up: thermotectonic effects on the southernmost Mantiqueira Province, Brazil. Journal of the Geological Society, v. 176, n. 6, p. 1056-1075, 2019. DOI: 10.1144/jgs2019-018

    Abstract: Through the joint use of apatite fission tracks (AFT) and (U–Th)/He analysis in apatite (AHe) and zircon (ZHe), we evaluate the thermotectonic evolution of the Sul-Rio-Grandense Shield (SRGS), southernmost Mantiqueira Province, Brazil. Formed during the assembly of West Gondwana (Neoproterozoic), the shield comprises four tectonostratigraphic terranes separated by regional faults and shear zones. The central and eastern terranes present Mesozoic AFT ages, whereas the western terrane ages are mostly late Paleozoic. AHe ages show considerable dispersion, although most are Mesozoic. ZHe ages from the east are early Permian, whereas the west presents Devonian ages. Inverse thermal modelling indicates a Devonian to Carboniferous cooling phase in the west, time correlated with orogenies occurring at the SW margin of Gondwana, which affected the regional geodynamics and are possibly linked to limited uplift of the shield. From the Permian to Jurassic a major cooling phase took place in the SRGS, probably related to lithosphere thinning and uplift preceding the South Atlantic rifting. Samples closer to the Atlantic coast suggest a subtle reheating after this event, provisionally linked to a geothermal disturbance related to ocean opening and associated magmatism. A final post-Paleocene cooling phase towards surface conditions affected the entire SRGS.

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  • IPEN-DOC 25794

    SANTANA, JESSICA C.C. de C.; SILVA, REJANE M.P. da ; ANTUNES, RENATO A.; SANTOS, SYDNEY F.. Surface analysis, microstructural characterization and local corrosion processes in decarburized SAE 9254 spring steel. Corrosion, v. 75, n. 12, p. 1474-1486, 2019. DOI: 10.5006/3234

    Abstract: The aim of the present work was to study the surface chemistry, microstructure and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 850 and 900 °C, and oil quenched. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by X-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization were employed to assess the global corrosion behavior of the decarburized samples. Scanning electrochemical microscopy (SECM) was used to evaluate the influence of decarburization on the local corrosion activity. Microstructural characterization and XPS analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and Si oxides in the decarburized layer.

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  • IPEN-DOC 26499

    AGODI, C.; CAPPUZZELLO, F.; ACOSTA, L.; ALTANA, C.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J.I.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CHARON GARCIA, L.E.; CHAVEZ LOMELI, E.R.; CIRALDO, I.; COLONNA, M.; D’AGOSTINO, G.; DJAPO, H.; GERONIMO, G. de; DELAUNAY, F.; DE LOS RIOS, K.; DESHMUKH, N.; FERRARESI, C.; FERREIRA, J.L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; HACISALIHOGLU, A.; HUERTA-HERNANDEZ, A.; KOTILA, J.; KUCUK, Y.; IAZZI, F.; LA FAUCI, L.; LANZALONE, G.; LA VIA, F.; LAY, J.A.; LENSKE, H.; LINARES, R.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MAS RUIZ, J.; MEDINA, N.H.; MENDES, D.R.; MEREU, P.; MORALLES, M. ; NERI, L.; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; RIES, P.; RODRIGUES, M.R.D.; RUSSO, A.D.; RUSSO, G.; SANTOPINTO, E.; SANTOS, R.B.B.; SERBINA, L.; SGOUROS, O.; SILVEIRA, M.A.G. da; SOLAKCI, S.O.; SOULIOTIS, G.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VSEVOLODOVNA, R.I.M.; VARGAS HERNANDEZ, H.; WANG, J.S.; WERNER, V.; YANG, Y.Y.; YILDIRIM, A.; ZAGATTO, V.A.B.. Recent results on Heavy-Ion induced reactions of interest for 0νββ decay. Journal of Physics: Conference Series, v. 1308, p. 1-5, 2019. DOI: 10.1088/1742-6596/1308/1/012002

    Abstract: An updated overview of recent results on Heavy-Ion induced reactions of interest for neutrinoless double beta decay is reported in the framework of the NUMEN project. The NUMEN idea is to study heavy-ion induced Double Charge Exchange (DCE) reactions with the aim to get information on the nuclear matrix elements for neutrinoless double beta (0νββ) decay. Moreover, to infer the neutrino average masses from the possible measurement of the half- life of 0νββ decay, the knowledge of the nuclear matrix elements is a crucial aspect.

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  • IPEN-DOC 26694

    QUITERO, MAYRA F.Z.; SIRIANI, LUCIANA K.; AZEVEDO, CYNTHIA S. de; FREITAS, ANDERSON Z. de ; SCARAMUCCI, TAIS; SIMIONATO, MARIA R.L.; MATOS, ADRIANA B.. Optical coherence tomography and polarized light microscopy for the evaluation of artificial caries: a preliminary study. General Dentistry, v. 67, n. 1, p. e1-e6, 2019.

    Abstract: This study was designed to investigate whether there is a correlation between the findings of optical coherence tomography (OCT) and polarized light microscopy (PLM) when these techniques are used to evaluate standard enamel white-spot lesions developed by distinct cariogenic challenges. Bovine enamel fragments (N = 168) were randomly allocated into 6 experimental groups according to the microbiologic model (Streptococcus mutans UA159, Streptococcus sobrinus ATCC 33478, or mixed S mutans and S sobrinus) and carbohydrate sources (1% sucrose or combined 1% sucrose and 1% starch). Specimens were examined by OCT and PLM every day within a period of 7 days. Five measurements of demineralization depth were recorded for each specimen, and means were calculated. Data were analyzed with analysis of variance and Tukey tests (α = 0.05), and a correlation test was performed. All cariogenic challenges created sub-superficial lesions. In both the OCT and PLM analyses, the demineralization depth reached its peak between days 6 and 7 of the cariogenic challenge, except for the group challenged with S sobrinus supplemented with combined sucrose and starch; for that group, demineralization peaked on day 5 in the OCT analysis. There was a significant correlation between OCT and PLM (P = 0.00; r = 0.842). This preliminary study suggests that OCT is a reliable, nondestructive method to measure the demineralization depth of enamel whitespot lesions, which can be useful for the laboratory and has potential for clinical studies. Using the 1% sucrose and S mutans model for 6 days is a simple and effective method to induce enamel caries–like lesions without compromising the depth and morphologic features of the obtained lesions.

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  • IPEN-DOC 26693

    SCAGLIUSI, SANDRA R. ; CARDOSO, ELISABETH C.L. ; LUGAO, ADEMAR B. . Radiation effects on crosslinking of butyl rubber compounds. Acta Scientific Microbiology, v. 2, n. 9, p. 160-164, 2019. DOI: 10.31080/ASMI.2019.02.0356

    Abstract: When butyl rubbers are subjected to high energy radiation, they form easy free radicals that initiate various chemical reactions. These reactions alter the molecular distribution of irradiated rubbers by crosslinking or scission affect their physical and mechanical properties. This work aims to the analysis of effect induced by γ-exposure on the crosslinking density in butyl rubbers by swelling measurements accomplished before and after irradiation at 25, 50, 100 and 200 kGy, with further evaluation of crosslinking density accomplished by Flory-Rehner equation; this is a proper procedure for the qualification of radiation resistance. It can be noticed that changes in material structure was due to build-up of new three-dimensional network in studied rubbers. Changes in crosslinking density of butyl rubber compounds emphasize that degradation mechanism is strongly influenced by gamma-radiation doses higher than 50 kGy, since chain scission process predominates over crosslinking reaction.

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  • IPEN-DOC 26692

    MACHADO, M. ; MORAES, L.P.R. ; RODRIGUES, L.N. ; TABANEZ, M. ; FERRAZOLI, M.; FONSECA, F.C. . Evaluation of Fe-doped CGO electrolyte for application in IT-SOFCs. ECS Transactions, v. 91, n. 1, p. 1209-1216, 2019. DOI: 10.1149/09101.1209ecst

    Abstract: A challenge encountered with intermediate temperature solid oxide fuel cells (IT-SOFCs) is lowering the densification temperature of the doped ceria electrolyte and improving its ionic conductivity. Ceria doped with 10 mol% gadolinium oxide and 0, 1, 5 mol% iron oxide were synthesized by a low temperature precipitation route based on hexamethylenetetramine as the precipitating agent. The as-synthesized precursors are nanocrystalline powders with a homogeneous morphology. Co-doping with Fe3+ changes the sintering behaviour of the doped cerium oxide and favours densification at lower temperatures. Through a comprehensive elementary, structural, microstructural and electrochemical analysis of the co-doped cerium oxide, it was established the doping mechanism of Fe3+ and its effect on the bulk and grain boundary conductivities. The overall aim is to evaluate its suitability for application as an electrolyte in IT-SOFC applications.

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  • IPEN-DOC 26691

    MACHADO, M. ; MORAES, L.P.R. ; RODRIGUES, L.N. ; RODRIGUES, T.S. ; FONSECA, F.C. . Lowering the sintering temperature of a SOFC by morphology control of the electrolyte powder. ECS Transactions, v. 91, n. 1, p. 1193-1199, 2019. DOI: 10.1149/09101.1193ecst

    Abstract: Solid oxide fuel cells are fabricated by two-step sintering at low temperature by controlling the morphology of the gadolinium-doped cerium oxide (GDC) electrolyte powders. The GDC electrolyte was synthesized by a hydrothermal route to obtain highly reactive nanorods that can fully densify at temperatures around 1150 °C. The developed system consists of the GDC electrolyte support, lanthanum strontium cobalt ferrite (LSCF) cathode and Ni/GDC anode. The electrolyte support was prepared by uniaxial die pressing and sintered at 1150 °C, and fuel cells were obtained by co-sintering electrode layers at the same temperature. The performance of the cell was evaluated in hydrogen at intermediate temperatures (IT). The experimental results indicate that high-performance IT-SOFC can be obtained at low sintering temperatures by controlling the morphology of electrolyte powder.

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  • IPEN-DOC 26690

    BRAGA, ELISABETE S.; AZEVEDO, JULIANA S.; KUNIYOSHI, LEONARDO; FAVARO, DEBORAH I.T. . Zn, Co, Cr, As, and genotoxic effects in the ichthyofauna species from polluted and non-polluted/protected estuaries of the São Paulo coast, Brazil. Anais da Academia Brasileira de Ciências, v. 91, n. 4, p. 1-18, 2019. DOI: 10.1590/0001-3765201920190066

    Abstract: The human impact on estuarine regions results in an increasing concentration of trace elements in the environment, exposing aquatic organisms. In this study, Zn, Co, Cr, and As were determined in the muscle tissue of some fish species from Santos-São Vicente (SSV), a recognized polluted region, and in the Cananeia estuary (CAN). Genotoxicity was also determined for the evaluation of the chronic effect on ichthyofauna, to enlarge the bank of environmental data regarding the effects of pollution, and to suggest other fish bioindicator species that may contribute to monitoring programs. The obtained data showed a similar profile of an accumulation of Co and Zn in Micropogonias furnieri and Chaetodipterus faber, where: Santos Bay > CAN > inner area of SSV. A low frequency of micronucleus was observed. However, in general, fish from the inner area of the SSV estuary presented more nuclear abnormalities than fish from Santos Bay and CAN. In the inner area of SSV, Centropomus paralelus and Diapterus rhomneus showed more changes than other fish species. It was possible to consider that the habits of each species, contributed to a different profile of trace element accumulation, followed by the chemical components in the organism offering different vulnerability.

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  • IPEN-DOC 26689

    SAMPAIO, CAMILA S.; ARIAS, JESSICA F.; ATRIA, PABLO J.; CACERES, EDUARDO; DIAZ, CAROLINA P.; FREITAS, ANDERSON Z. ; HIRATA, RONALDO. Volumetric polymerization shrinkage and its comparison to internal adaptation in bulk fill and conventional composites: A μCT and OCT in vitroanalysis. Dental Materials, v. 35, n. 11, p. 1568-1575, 2019. DOI: 10.1016/j.dental.2019.07.025

    Abstract: Objective. To quantify the volumetric polymerization shrinkage (VPS) of different conventional and bulk fill resin composites, through micro-computed tomography (μCT), and qualitative comparison of gap formation through optical coherence tomography (OCT). Methods. Box-shaped class I cavities were prepared in 30 third-molars and divided into 5 groups (n = 6): G1- Filtek Z100 (Z100); G2- Tetric Evoceram Bulk Fill (TEC); G3- Tetric EvoFlow Bulk fill (TEF); G4- Filtek Bulk fill (FBU); and G5- Filtek Bulk fill Flowable (FBF). All groups were treated with Adper Single Bond Plus adhesive and light cured (Bluephase 20i). Each tooth was scanned three times using a μCT apparatus: after cavity preparation (empty scan); after cavity filling (uncured scan) and after light curing of the restorations (cured scan). The μCT images were imported into a three-dimensional rendering software, and volumetric polymerization shrinkage percentage was calculated (%) for each sample. In the same images, interfacial gaps in the pulpal floor were qualitatively evaluated. After μCT evaluation, the pulpal floor from each tooth was polished until a thin tooth structure was obtained and OCT images were obtained by scanning the pulpal portion. Gap formation was observed and qualitatively compared to the μCT images.

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  • IPEN-DOC 26687

    BELLONI, MARCIO ; CONTI, THADEU das N. . The connection of solar generators to the electricity distribution network as a means of mitigating environmental impacts by dispensing the banks of accumulators. Energy and Power Engineering, v. 11, n. 12, p. 392-397, 2019. DOI: 10.4236/epe.2019.1112026

    Abstract: Solar generators are known worldwide as a means of generating clean electricity. However, the existence of battery banks causes alarm in the community by the existence of materials that degrade the environment by discarding them outside the norm. With the publication of Regulatory Standards 482/12 and 687/15, solar generators can be connected to the distribution grid, which serves as a means of accumulating the generated energy. The new changes were seen as an economic possibility, but there are more benefits. This has proved very important to make solar generation greener because it no longer needs large battery banks. This has also been shown to significantly lower the final value of the solar generator, bringing economic benefits. This paper aims to analyze the economic and environmental benefits of battery bank distribution in solar generation.

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  • IPEN-DOC 26686

    CREMA, E.; PAES, B.; ZAGATTO, V.A.B.; HUIZA, J.F.P.; LUBIAN, J.; SHORTO, J.M.B. ; SIMÕES, R.F.; MONTEIRO, D.S.; ADDED, N.; MORAIS, M.C.; GOMES, P.R.S.. Strong neutron-transfer coupling effects in the reaction mechanism of the 18O + 64Zn system at energies near the Coulomb barrier. Physical Review C, v. 100, n. 5, p. 054608-1 - 054608-11, 2019. DOI: 10.1103/PhysRevC.100.054608

    Abstract: The precise quasielastic excitation function for the 18O + 64Zn system was measured at energies near and below the Coulomb barrier at θlab = 161◦, from which its correlated quasielastic barrier distribution was derived. The excitation functions for the two-neutron, α, and tritium transfer reactions have also been measured at the same conditions. These data were well described by the coupled channel and coupled reaction channel calculations. The comparison of the data with theoretical calculations shows the strong influence of three inelastic channels in the coupling process: the quadrupole and octupole vibrational states of 64Zn, 2+ 1 and 3− 1 , and the quadrupole vibrational state of 18O, 2+ 1 . In addition, theoretical calculations indicate that the two-neutron stripping is mostly due to a one-step process, which has a striking effect on the reaction mechanism of this system.

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  • IPEN-DOC 26685

    MANTECON, J.G. ; NETO, M.M. . Simplified CFD model of coolant channels typical of a plate-type fuel element: an exhaustive verification of the simulations. Brazilian Journal of Radiation Sciences, v. 7, n. 2B, p. 1-16, 2019. DOI: 10.15392/bjrs.v7i2B.621

    Abstract: The use of parallel plate-type fuel assemblies is common in nuclear research reactors. One of the main problems of this fuel element configuration is the hydraulic instability of the plates caused by the high flow velocities. The current work is focused on the hydrodynamic characterization of coolant channels typical of a flat-plate fuel element, using a numeri-cal model developed with the commercial code ANSYS CFX. Numerical results are compared to accurate analytical solutions, considering two turbulence models and three different fluid meshes. For this study, the results demonstrated that the most suitable turbulence model is the k- model. The discretization error is estimated using the Grid Conver-gence Index method. Despite its simplicity, this model generates precise flow predictions.

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  • IPEN-DOC 26683

    OLIVEIRA, LEANDRO A. de; SILVA, REJANE M.P. da ; ANTUNES, RENATO A.. Scanning Electrochemical Microscopy (SECM) study of the electrochemical behavior of anodized AZ31B magnesium alloy in simulated body fluid. Materials Research, v. 22, n. 5, p. 1-8, 2019. DOI: 10.1590/1980-5373-MR-2019-0079

    Abstract: In this work, scanning electrochemical microscopy (SECM) was employed to study the corrosion behavior of anodized AZ31B magnesium alloy exposed to simulated body fluid. SECM measurements were carried out in surface generation/tip collection mode. The hydrogen evolution flux caused during corrosion of the magnesium alloy was oxidized at the ultra-microelectrode (UME). Thus, this experimental procedure allowed evaluating the effect of the anodic protection in this alloy from the SECM analysis of Z- approximation curves, cyclic voltammograms and topographic maps. The results evidence differences in the local electrochemical response of magnesium alloy in the anodized and pristine conditions. The main sites of H2 evolution were verified in the magnesium alloy without anodizing at short exposure times.

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  • IPEN-DOC 26682

    ISHIBAZAWA, AKIHIRO; PRETTO, LUCAS R. de ; ALIBHAI, A. YASIN; MOULT, ERIC M.; ARYA, MALVIKA; SOROUR, OSAMA; MEHTA, NIHAAL; BAUMAL, CAROLINE R.; WITKIN, ANDRE J.; YOSHIDA, AKITOSHI; DUKER, JAY S.; FUJIMOTO, JAMES G.; WAHEED, NADIA K.. Retinal nonperfusion relationship to arteries or veins observed on widefield optical coherence tomography angiography in diabetic retinopathy. Investigative Ophthalmology & Visual Science, v. 60, n. 13, p. 4310-4318, 2019. DOI: 10.1167/iovs.19-26653

    Abstract: PURPOSE. To evaluate whether retinal capillary nonperfusion is found predominantly adjacent to arteries or veins in eyes with diabetic retinopathy (DR). METHODS. Sixty-three eyes from 44 patients with proliferative DR (PDR) or non-PDR (NPDR) were included. Images (12 3 12-mm) foveal-centered optical coherence tomography (OCT) angiography (OCTA) images were taken using the Zeiss Plex Elite 9000. In 37 eyes, widefield montages with five fixation points were also obtained. A semiautomatic algorithm that detects nonperfusion in full-retina OCT slabs was developed, and the percentages of capillary nonperfusion within the total image area were calculated. Retinal arteries and veins were manually traced. Based on the shortest distance, nonperfusion pixels were labeled as either arterial-side or venous-side. Arterial-adjacent and venous-adjacent nonperfusion and the A/V ratio (arterial-adjacent nonperfusion divided by venous-adjacent nonperfusion) were quantified. RESULTS. Twenty-two eyes with moderate NPDR, 16 eyes with severe NPDR, and 25 eyes with PDR were scanned. Total nonperfusion area in PDR (median: 8.93%) was greater than in moderate NPDR (3.49%, P < 0.01). Arterial-adjacent nonperfusion was greater than venousadjacent nonperfusion for all stages of DR (P < 0.001). The median A/V ratios were 1.93 in moderate NPDR, 1.84 in severe NPDR, and 1.78 in PDR. The A/V ratio was negatively correlated with the total nonperfusion area (r ¼ 0.600, P < 0.0001). The results from the widefield montages showed similar patterns. CONCLUSIONS. OCTA images with arteries and veins traced allowed us to estimate the nonperfusion distribution. In DR, smaller nonperfusion tends to be arterial-adjacent, while larger nonperfusion tends toward veins.

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  • IPEN-DOC 26681

    GERALDO, BIANCA ; ARAUJO, LEANDRO G. de ; TADDEI, MARIA H.T.; FERREIRA, MARCELO T.; MADUAR, MARCELO F. ; VICENTE, ROBERTO ; MARUMO, JULIO T. . Radiochemical characterization of spent filter cartridges from the primary circuit of a research reactor. Journal of Radioanalytical and Nuclear Chemistry, v. 322, n. 3, p. 1941-1951, 2019. DOI: 10.1007/s10967-019-06864-4

    Abstract: Radiochemical-based analyses have been used for the characterization of radioactive waste. Nevertheless, the determination of alpha, beta and gamma emitters by radiochemical analysis of spent cartridge filters from a swimming-pool type reactor has not been previously addressed. This work aims at identifying and quantifying the radionuclides present in this waste, including the difficult to measure radionuclides. The distribution of the radionuclides in the filter was investigated by the determination of gamma-emitting nuclides and the z-score of the measured activity concentrations. The results indicated that all the filters are homogeneous, meeting the homogeneity criteria recommended by the International Atomic Energy Agency.

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  • IPEN-DOC 26677

    CABRAL, EDUARDO L.L. ; SABUNDJIAN, GAIANE ; CONTI, THADEU das N. . Pixel-position-based lossless image compression algorithm. International Journal of Innovative Studies in Sciences and Engineering Technology, v. 5, n. 12, p. 21-30, 2019.

    Abstract: In this paper we present a novel lossless image compression method that is very simple and fast. The method uses linear prediction followed by arithmetic coding. Different prediction functions are used to estimate the intensity of image pixels. Two variants of the prediction algorithm are presented. One variant uses two different prediction functions and the other uses three different prediction functions. The position of the pixel in the image determines which prediction function is used. The method can be applied for images of any size and of high bit-depths. Standard images available in the literature are used to test the method. The compression ratios obtained with the proposed method are compared with the compression ratios obtained with the JPEG-LS and JPEG2000 methods and the results are satisfactory.

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  • IPEN-DOC 26676

    SILVEIRA, SILVESTRE J.S. da; SPENCER, PATRICK J. . Perfil clínico e epidemiológico da Leishmaniose Tegumentar Americana no Hospital de Doenças Tropicais da Universidade Federal do Tocantins / Clinical and epidemiological profile of American Cutaneous Leishmaniasis at the Tropical Diseases Hospital of the Federal University of Tocantins. Brazilian Journal of Development, v. 5, n. 11, p. 24780-24793, 2019. DOI: 10.34117/bjdv5n11-158

    Abstract: O objetivo principal deste artigo é caracterizar o Perfil Clínico e Epidemiológico da Leishmaniose Tegumentar Americana, no período de 2010 a 2016, do Hospital de Doenças Tropicais (HDT) da Universidade Federal do Tocantins no município de Araguaína-TO, área considerada endêmica para a referida doença. Como objetivos específicos, pretende-se contribuir para o conhecimento da doença nos aspectos de: a) mostrar a distribuição geográfica regional da LTA; b) caracterizar o perfil epidemiológico regional da LTA; c) retratar as formas clínicas e sua frequência na região; d) descrever os critérios diagnósticos utilizados no HDT; e d) descrever as terapêuticas empregadas para LTA no Serviço e discutir sobre os dados de acordo com a literatura atual, visto que a doença que faz parte da lista de doenças negligenciada, e as mesmas são as principais causas de morbidade e mortalidade em todo o mundo.

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  • IPEN-DOC 26675

    CARMO, L.S. do ; WATANABE, S. ; DEWITT, R.. OSL-SAR dating of sediments from Brazilian aeolian system: Dama Branca, Rio de Janeiro, morphodynamic study. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-17, 2019. DOI: 10.15392/bjrs.v7i2A.688

    Abstract: It has been reported that the formation and stabilization of coastal dune fields in Brazil have a dependence on the climatic changes, Relative Sea Level (RSL) variations, etc. In this work, a dune field known as “Dama Branca”, located in the city of Cabo Frio, Rio de Janeiro, has been studied to understand its mobility. Dating by trapped charge dating techniques as Optically Stimulated Luminescence (OSL) using the Single Aliquot Regenerative protocol (SAR), helps us to understand the formation and dynamics of aeolian systems in Brazil. Samples from two positions; DB and 2DB, were collected from different heights and points for dating. The results obtained by OSL-SAR showed that ages decrease as the height from the dune base increases and older samples are found in deeper horizontal positions. The ages from the base of the studied dunes indicated that its stabilization occurred during the recess of the sea level and that erosion caused by the wind action is revealing an old generation of this dune filed.

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  • IPEN-DOC 26674

    SEO, E.S.M. ; SILVA, N.S. da; BARBOSA, I.T.F.; ATHIE, A.A.R.; LUCA, A.C. de. Obtenção de um copo mais sustentável: preparação e caracterização de fibras naturais e de biocompósitos / Obtaining a more sustainable cup: preparation and characterization of natural fibers and biocomposits. InterfacEHS - Revista de Saúde, Meio Ambiente e Sustentabilidade, v. 14, n. 2, p. 3-12, 2019.

    Abstract: O presente artigo tem como objetivo contribuir apresentando tanto as características de fibras naturais de cana-de-açúcar e de coco verde, como avaliar à resistência à compressão dos biocompósitos. No processo de mercerização foram testadas as concentrações de hidróxido de sódio e na fabricação de copos de polietileno, foram adicionadas fibras com concentrações de 3%, 5% e 7% em massa. Na fabricação de copos por processo de injeção foram adicionadas fibras como reforço do polímero de alta densidade. As fibras naturais foram tratadas por processo de mercerização e caracterizadas por meio das técnicas de picnometria por gás hélio, fluorescência por raios X, análise termogravimétrica e microscopia eletrônica de varredura, evidenciado que o processo é adequado para obtenção de fibras sem a presença de celulose ou hemicelulose. Verificou-se que as fibras naturais com concentrações de 5% em massa apresentaram maiores resistência a tração.

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  • IPEN-DOC 26672

    ALMEIDA, JORGE V. de; SIQUEIRA, GLAUCIO L.; MOSSO, MARBEY M.; SARTORI, CARLOS A.F. . Mu-negative metamaterials seen as band-limited non-foster impedances in inductive power transmission systems. Journal of Microwaves, Optoelectronics and Electromagnetic Applications, v. 18, n. 4, p. 492-504, 2019. DOI: 10.1590/2179-10742019v18i41625

    Abstract: In the last decade, various works have demonstrated that a class of artificial material called metamaterials (MTM) can synthesize mu-negative (MNG) media capable of evanescent-wave focusing which largely enhances the magnetic coupling between coils, which is the basic mechanism of Inductive Power Transmission (IPT) systems. In the present work, MTM-enhanced coupling in IPT systems is examined through analytical and numerical results, which are validated by experimental data. Adopting a transmission-line (TL) based approach to describe the general MTM-enhanced IPT system, it is evidenced that MNG MTMs can be interpreted as a negative impedance from a circuital point of view.

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  • IPEN-DOC 26671

    FONSECA, DANIELA P. ; MONTEIRO, WALDEMAR A. . The microstructure and properties of copper with ceria nanoparticles addition. Journal of Materials Science and Chemical Engineering, v. 7, n. 10, p. 40-48, 2019. DOI: 10.4236/msce.2019.710004

    Abstract: Copper-based composites strengthened by ceria nanoparticles were processed by conventional powder metallurgy: mixing (30 min and 46 rpm), compaction (cold, uniaxial, 1080 MPa for 10 s) and sintering (800˚C for 6 h in vacuum atmosphere of 10−5 torr). It was studied the microstructure (optical microscopy, scanning electron microscopy), X-ray diffraction with Rietveld refinement and some properties (electrical conductivity, Vickers hardness and fracture analysis) of the compositions 92 wt% Cu - 8 wt% CeO2 and 80 wt% Cu - 20 wt% CeO2. The results showed uniform phase distribution, low porosity and ceria disperse inside copper grain. In despite of properties, the composites had electrical conductivity of 38% IACS and 15% IACS and hardness of 69 and 88 HV5, respectively. The results of 92 wt% Cu - 8 wt% CeO2 composites were promising, and they are in according with actual literature.

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  • IPEN-DOC 26670

    MASOUMI, MOHAMMAD; LIMA, NELSON B. de ; TRESSIA, GUSTAVO; SINATORA, AMILTON; GOLDENSTEIN, HELIO. Microstructure and crystallographic orientation evolutions below the superficial white layer of a used pearlitic rail. Journal of Materials Research and Technology, v. 8, n. 6, p. 6275-6288, 2019. DOI: 10.1016/j.jmrt.2019.10.021

    Abstract: Although several studies have been conducted on the mechanism of the formation ofwhite layer by cyclic large shear deformation, and its effect on rolling contact fatigue,limited research has been carried out to find a correlation between sub-superficial layerof running contact surface and the crystallographic orientation, microstructural changes,and distribution of shear deformation and dislocation density. In order to understandthe microstructural evolution (i.e., microstructure and crystallographic orientation) a usedpearlitic rail sample removed from the heavy-haul railroad was investigated in the currentwork. A very thin superficial white layer was observed, approximately 15 m below the run-ning contact surface. X-ray diffraction analysis confirmed the formation of a supersaturatedferrite phase with carbon content of approximately 3.78 C wt%. It could be attributed to thecementite dissolution due to severe shear and compressive stresses, during intense shearplastic deformation, from the rail-wheel interaction. The dominance of {110} ferrite grainsparallel to the rail direction was characterised, in the transition layer between white layerand non-deformed pearlite structure, by X-ray diffraction and electron backscattered diffrac-tion techniques. Formation of these grains, corresponding to the closed-pack plane of theferrite matrix at the transition region, leads to great ductility and retarded crack formation.

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  • IPEN-DOC 26669

    SIERRA, JULIAN H.; RANGEL, RICARDO C.; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ALAYO, MARCO I.; CARVALHO, DANIEL O.. Low-loss pedestal Ta2O5 nonlinear optical waveguides. Optics Express, v. 27, n. 26, p. 37516-37521, 2019. DOI: 10.1364/OE.27.037516

    Abstract: In this work, we investigate a pedestal tantalum oxide (Ta2O5) material platform for integrated nonlinear optics (NLO). In order to achieve low propagation losses with this material, pedestal waveguides with Ta2O5 cores were designed. The nonlinear refractive index n2 of this new platform was obtained by measuring the amount of spectral broadening due to self-phase modulation (SPM) of 23 fs optical pulses at 785 nm propagating through the waveguides. In this manner, a nonlinear index of (5.8 2.0) 10􀀀19 m2W􀀀1 was found for this material, which is in good agreement with values reported in related works where strip waveguides were used for a similar purpose. Furthermore, due to the pedestal configuration, propagation losses as low as 1.6 dB cm􀀀1 for narrow waveguides and 0.1 dB cm􀀀1 for large waveguides were obtained. Finite element method (FEM) mode analysis was performed to calculate the mode characteristics, as well as the effective areas of the waveguides. The high nonlinear and linear refractive indices, wide bandgap and low propagation losses make this platform ideal for applications extending from the visible into the mid-IR regions of the optical spectrum. Due the large gap, Ta2O5 should have low two photon absorption at the near-IR as well.

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  • IPEN-DOC 26668

    HAMLAT, S.; PAN, P.; FERREIRA, A.; MAZZILLI, B.; ST‑AMANT, N.; CERUTTI, G.; GOMEZ, I.M.F.; ESPARZA, L.J.R.; PONCE, E.Q.; CUBERO, M.; ODINO, R.; PINONES, O.; PITOIS, A.; RINKER, M.. International Atomic Energy Agency’s Analytical Laboratories for the Measurement of Environmental Radioactivity network: experiences and perspectives in the North and Latin America region. Radiation Protection and Environment, v. 42, n. 3, p. 68-76, 2019. DOI: 10.4103/rpe.RPE_24_19

    Abstract: The International Atomic Energy Agency (IAEA) Network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) is a worldwide network of laboratories capable of providing reliable and timely analysis of radionuclides in environmental samples during normal or accidental/intentional events that result in the release of radioactivity in the environment. ALMERA is coordinated by the Environment Laboratories of the IAEA and organized into five regional groups, including the North and Latin America region (NLAR), led by the Canadian Nuclear Safety Commission. Capacity building in the NLAR for the measurements of environmental radioactivity is achieved through qualitative study that consists of experiences of ALMERA core activities and perspectives of the regional initiatives, respectively. Outcomes’ analysis showed that the ALMERA core activities have contributed to the improvements of the analytical capacity and capability, and the regional initiatives assisted in the strengthening of the collaboration and networking, in the NLAR region. The immediate impact of these achievements consisted of gaining technical competence in measuring environmental radioactivity and establishing a network of laboratories. In the long term, sustained efforts between ALMERA and the regional coordination will continue upgrading national and regional competence in the radio analytical services.

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  • IPEN-DOC 26667

    RIBEIRO, ELOANA P. ; COUTO, ANTONIO A. ; OLIVEIRA, LEANDRO A. de; ANTUNES, RENATO A.. Influence of the treatment time on the surface chemistry and corrosion behavior of cerium-based conversion coatings on the AZ91D magnesium alloy. Materials Research, v. 22, suppl.1, p. 1-10, 2019. DOI: 10.1590/1980-5373-MR-2018-0862

    Abstract: The aim of the present work was to investigate the effect of the treatment time on the surface chemistry and corrosion behavior of cerium-based chemical conversion coatings on the AZ91D magnesium alloy. The conversion coating was prepared by the immersion technique from a bath consisting of 0.05 mol.L-1 Ce(NO3)3.6H2O and 0.254 mol.L-1 H2O2 (30 wt.%) for times ranging from 20 s to 120 s. The surface chemistry was examined by X-ray photoelectron spectroscopy (XPS). The corrosion behavior was assessed by electrochemical impedance spectroscopy and potentiodynamic polarization. XPS analysis detected the presence of cerium oxides (Ce2O3 and CeO2) and cerium/ magnesium hydroxides. The best corrosion behavior was observed for the treatment conducted for 60 s. The results are discussed with respect to coating morphology and composition.

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  • IPEN-DOC 26663

    PEREIRA, JONATHAS X.; SANTOS, SOFIA N. dos ; PEREIRA, THAIS C.; CABANEL, MARIANA; CHAMMAS, ROGER; OLIVEIRA, FELIPE L. de; BERNARDES, EMERSON S. ; EL-CHEIKH, MARCIA C.. Galectin-3 regulates the expression of tumor glycosaminoglycans and increases the metastatic potential of breast cancer. Journal of Oncology, v. 2019, p. 1-15, 2019. DOI: 10.1155/2019/9827147

    Abstract: Galectin-3 (Gal-3) is a multifunctional β-galactoside-binding lectin that once synthesized is expressed in the nucleus, cytoplasm, cell surface, and extracellular environment. Gal-3 plays an important role in breast cancer tumors due to its ability to promote interactions between cell-cell and cell-extracellular matrix (ECM) elements, increasing tumor survival and metastatic dissemination. Still, the mechanism by which Gal-3 interferes with tumor cell migration and metastasis formation is complex and not fully understood. Here, we showed that Gal-3 knockdown increased the migration ability of 4T1 murine breast cancer cells in vitro. Using the 4T1 orthotopic breast cancer spontaneous metastasis mouse model, we demonstrated that 4T1-derived tumors were significantly larger in the presence of Gal-3 (scramble) in comparison with Gal-3 knockdown 4T1-derived tumors. Nevertheless, Gal-3 knockdown 4T1 cells were outnumbered in the bone marrow in comparison with scramble 4T1 cells. Finally, we reported here a decrease in the content of cell-surface syndecan-1 and an increase in the levels of chondroitin sulfate proteoglycans such as versican in Gal-3 knockdown 4T1 cells both in vitro and in vivo. Overall, our findings establish that Gal-3 downregulation during breast cancer progression regulates cell-associated and tumor microenvironment glycosaminoglycans (GAGs)/proteoglycans (PG), thus enhancing the metastatic potential of tumor cells.

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  • IPEN-DOC 26662

    SANTOS, SILAS C. dos ; RODRIGUES JUNIOR, ORLANDO ; CAMPOS, LETICIA L. . Formation and EPR response of europium-yttria micro rods. QUARKS: Brazilian Electronic Journal of Physics, Chemistry and Material Science, v. 1, n. 1, p. 53-56, 2019. DOI: 10.34019/2674-9688.2019.v1.28229

    Abstract: Designing new materials with suitable dose-response efficiency is a great challenge in radiation dosimetry search. Yttria (Y2O3) has excellent optical, mechanical, chemical, and thermal properties. Besides, yttria exhibits crystal characteristics that provide insertion of other rare earths, forming innovative materials. Nevertheless, there are quite few studies on formation, microstructural and EPR response evaluation of yttria. This work reports the formation and EPR characterization of europium-yttria micro rods for radiation dosimetry. Ceramic rods obtained by sintering at 1600ºC/4h in air were exposed to gamma radiation with doses from 1Gy to 150kGy. Particle, microstructural and dosimetry characterizations were performed by PCS, XRD, SEM, OM, and EPR techniques. As sintered europiumyttrium rods exhibited dense microstructure (90% theoretical density) and linear EPR dose response behavior up to 10kGy. These results show that europium-yttria is a promising material for radiation dosimetry.

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  • IPEN-DOC 26659

    BRANCO, ISABELA S.L. ; ANTUNES, PAULA C.G. ; SIQUEIRA, PAULO T.D. ; SHORTO, JULIAN M.B. ; YORIYAZ, HELIO . Estudo dos efeitos de composição e densidade de materiais tecido equivalentes na distribuição de dose longitudinal em protonterapia / Study of the composition and density effects of tissue equivalent materials on the longitudinal dose distribution in proton therapy. Revista Brasileira de Física Médica, v. 13, n. 3, p. 2-7, 2019. DOI: 10.29384/rbfm.2019.v13.n3.p2-7

    Abstract: A eficiência de procedimentos radioterápicos depende do equilíbrio entre o fornecimento de altas doses conformadas ao volume tumoral e a restrição das doses recebidas pelos tecidos e órgãos saudáveis circundantes. Sendo uma modalidade de radioterapia, a protonterapia destaca-se neste cenário por possuir vantagens dosimétricas, que, quando combinadas com avanços tecnológicos, permitem que um grande potencial na conformidade da distribuição de dose. Este trabalho visa contribuir em um estudo dosimétrico, especificamente considerando os efeitos da heterogeneidade devido à presença de materiais tecido equivalentes com diferentes densidades e composições químicas, de modo a analisar qual destes parâmetros exerce maior influência na distribuição de dose longitudinal. A metodologia desenvolvida neste trabalho foi baseada em simulações de Monte Carlo com o código GEANT4 (através da interface TOPAS). Os objetos simuladores cilíndricos representados foram compostos inteiramente por diversos materiais tecido-equivalentes. Três grupos de estudo guiaram as simulações, o primeiro manteve a composição e densidade originais dos materiais, ao seguinte foi atribuída a todos os materiais heterogêneos a mesma densidade da água, mas mantiveram-se suas composições químicas originais; e por fim, foram realizadas simulações com as densidades originais dos materiais heterogêneos e composição química da água para todos os casos. Através da análise da distribuição de dose longitudinal variando com a profundidade, foi possível observar o comportamento da influência dos parâmetros de composição e densidade no alcance do feixe (d90) para os diferentes materiais e energias analisados. O estudo mostrou que, o efeito que a densidade dos materiais tecido equivalentes exerce sobre a deposição de dose é mais expressivo que o efeito de sua composição. A maior exatidão no range de tratamento permite evitar uma sub ou sobre dosagem da área irradiada. Esta é uma das diversas linhas de pesquisa que contribuem para a diminuição das incertezas em protonterapia.

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  • IPEN-DOC 26658

    BOIANI, N.F. ; SILVA, V.H.O.; GARCIA, V.S.G. ; DEL SOLE, S.V. ; BORRELY, S.I. . Electron beam irradiation of pharmaceuticals aiming at toxicity reduction: a binary mixture of fluoxetine and propranolol. Ecotoxicology and Environmental Contamination, v. 14, n. 1, p. 53-58, 2019. DOI: 10.5132/eec.2019.01.06

    Abstract: Significant evidence is available in the literature justifying the search for treatment technologies or process combinations to improve the decomposition of dozens of pharmaceuticals in wastewater. Conventional processing techniques are insufficient in removal of the pharmaceuticals, for having resistant waste and low biodegradability. Electron beam irradiation (EBI) may play an important role in this context, and relatively low doses have been reported for such purposes. The objective of this study was to apply the process of irradiation with electron beam in order to reduce the toxic effects of fluoxetine, propranolol, and a binary mixture of these pharmaceuticals in aqueous solution. Ecotoxicological tests conducted in two model organisms, Daphnia similis microcrustacean, and Vibrio fischeri bacterium. It was observed that D. similis was more sensitive to the pharmaceuticals and binary mixture, when compared to V. fischeri. When EBI was applied, all doses showed significant reduction of toxicity for D. similis, and the opposite for V. fischeri, when only 5.0 kGy showed a significant reduced of toxicity for the pharmaceuticals and binary mixture. 5.0 kGy was the best removal efficiency for toxicity, approximately 80% for D. similis and 20% for V. fischeri.

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  • IPEN-DOC 26657

    CASTRO, DIONE P. de ; SARTORI, MARIANA do N. ; SILVA, LEONARDO G. de A. e . Effects of gamma radiation on the properties of the thermoplastic starch/poly (butylene adipate-co-terephthalate) blends. Materials Research, v. 22, suppl.1, p. 1-6, 2019. DOI: 10.1590/1980-5373-MR-2019-0072

    Abstract: The development of blends made from matrices of synthetic biodegradable polymers, and natural additives, are considered less environmentally aggressive materials. This work aimed to study the effects of gamma radiation on the properties of the thermoplastic starch (TPS)/poly(butylene adipateco- terephthalate) (PBAT). In this work, blends of TPS/PBAT were prepared with glycerol, castor oil and TWEEN® 80, which were prepared by extrusion and then subjected to the radiation process and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated increased thermal degradation for the F2 (composed by OM) and F3 (composed by OM and TWEEN® 80) regarding F0 (composed by glycerol) e F1 (composed by glycerol and TWEEN® 80) blends. A good blend component chemical interaction and partial miscibility for the blends F0 and F1 was observed and compared to the others. However, F2 and F3 blends did not present co-continuous phases; being that the XRD curve patterns were not altered by the gamma radiation. The tests performed demonstrated that the irradiated and non-irradiated samples did not have their properties significantly altered. Thus, it was concluded that it is feasible to replace castor oi l with glycerol in TPS/PBAT blends.

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  • IPEN-DOC 26656

    BARROS, JULIO O.A. de ; POLITANO, RODOLFO . Effects of frequency, temperature and test duration in the viscoelasticity of Brazilian hardwoods used in handmade musical instruments. Materials Research, v. 22, suppl.1, p. 1-5, 2019. DOI: 10.1590/1980-5373-MR-2019-0190

    Abstract: This study aims to make a comprehensive analysis on the viscoelastic behavior of typical tropical hardwoods and its influences in making musical instruments. For that a Dynamic-Mechanical Analysis was done and the mechanical parameters dependence on test control parameters like temperature, frequency and test duration time were measured. For Dalbergia Nigra the final value of Module of Elasticity (MOE) was 17551.0MPa and 0.022020 for tangent delta (tg(δ)), but a great variation in those parameters was observed during the tests, for all species the MOE increases and tg(δ) decreases, even with constant temperatures, which may be caused by water loss. Besides that, a discussion was made relating the obtained data and historical knowledge about the usages of the studied woods for musical instruments manufacture, and density was shown as the main variable for that purpose.

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  • IPEN-DOC 26655

    SOUZA FILHO, EDVAN A. de ; PIERETTI, EURICO F. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Effect of nitrogen-doping on the surface chemistry and corrosion stability of TiO2 films. Journal of Materials Research and Technology, v. 9, n. 1, p. 922-934, 2020. DOI: 10.1016/j.jmrt.2019.11.032

    Abstract: TiO2 and N-doped TiO2 films were grown on AISI 316 stainless steel substrates and on Si (100) by metallorganic chemical vapor deposition (MOCVD) at 400 ◦C and 500 ◦C. X-ray photoelectron spectroscopy, scanning electron microscopy, and contact angle techniques were used to characterize de films. The corrosion behavior was assessed by monitoring the open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization tests in 3.5 wt% NaCl solution at room temperature. The results show that 6.18 at% of nitrogen was introduced in the films grown at 400 ◦C and 8.23 at% at 500 ◦C, and that besides TiO2, nitrogen phases were identified. All the films are hydrophilic and the contact angles varied from 48◦ to 72◦. The films presented good homogeneity, low porosity and rounded grains in the range of 40–90 nm. The RMS roughness varied between 5.5 and 18.5 nm. Titanium dioxide films grown at 400 ◦C showed better corrosion resistance than those grown at 500 ◦C due to its compact morphology. Nitrogen-doping was not efficient to protect the substrate from corrosion.

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  • IPEN-DOC 26654

    TERADA, MAYSA ; QUEIROZ, FERNANDA M.; COSTENARO, HELEN; AYUSSO, VICTOR H. ; OLIVIER, MARJORIE; COSTA, ISOLDA ; MELO, HERCILIO G. de. Effect of cerium addition to a hydrothermal treatment on the corrosion protection of the tartaric-sulfuric acid anodized AA2524-T3. Corrosion, v. 75, n. 9, p. 1110-1117, 2019. DOI: 10.5006/3063

    Abstract: To protect Al alloys from corrosion, standard procedures in the aerospace industry use chromium-based acid anodizing with subsequent post-treatment steps also containing hexavalent chromium (Cr(VI)) ions. However, environmental and health related concerns associated with Cr(VI) have encouraged the search for new surface treatments providing effective corrosion protection without the drawback of generating toxic residues. In this investigation, a hydrothermal treatment in aqueous solution with cerium ions is proposed as a post-treatment for tartaric-sulfuric acid (TSA) anodizing, and its effects on the AA2524-T3 alloy corrosion resistance investigated. The effect of Ce on the characteristics of the surface film formed, such as morphology and corrosion resistance, is investigated by scanning electron microscopy and electrochemical impedance spectroscopy (EIS). The results show that the hydrothermal treatment in solution containing Ce(III) ions presents a less stable behavior than the treatment in boiling water. However, the results of the EIS experiments show recovery of the protective properties of the system, indicating that some self-healing properties must be imparted to the system.

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  • IPEN-DOC 26653

    BENAVENT-OLTRA, JOSE A.; ROMAN, ROBERTO; CASQUERO-VERA, JUAN A.; PEREZ-RAMIREZ, DANIEL; LYAMANI, HASSAN; ORTIZ-AMEZCUA, PABLO; BEDOYA-VELASQUEZ, ANDRES E.; MOREIRA, GREGORI de A. ; BARRETO, AFRICA; LOPATIN, ANTON; FUERTES, DAVID; HERRERA, MILAGROS; TORRES, BENJAMIN; DUBOVIK, OLEG; GUERRERO-RASCADO, JUAN L.; GOLOUB, PHILIPPE; OLMO-REYES, FRANCISCO J.; ALADOS-ARBOLEDAS, LUCAS. Different strategies to retrieve aerosol properties at night-time with the GRASP algorithm. Atmospheric Chemistry and Physics, v. 19, n. 22, p. 14149-14171, 2019. DOI: 10.5194/acp-19-14149-2019

    Abstract: This study evaluates the potential of the GRASP algorithm (Generalized Retrieval of Aerosol and Surface Properties) to retrieve continuous day-to-night aerosol properties, both column-integrated and vertically resolved. The study is focused on the evaluation of GRASP retrievals during an intense Saharan dust event that occurred during the Sierra Nevada Lidar aerOsol Profiling Experiment I (SLOPE I) field campaign. For daytime aerosol retrievals, we combined the measurements of the ground-based lidar from EARLINET (European Aerosol Research Lidar Network) station and sun–sky photometer from AERONET (Aerosol Robotic Network), both instruments co-located in Granada (Spain). However, for night-time retrievals three different combinations of active and passive remote-sensing measurements are proposed. The first scheme (N0) uses lidar night-time measurements in combination with the interpolation of sun–sky daytime measurements. The other two schemes combine lidar night-time measurements with nighttime aerosol optical depth obtained by lunar photometry either using intensive properties of the aerosol retrieved during sun–sky daytime measurements (N1) or using the Moon aureole radiance obtained by sky camera images (N2). Evaluations of the columnar aerosol properties retrieved by GRASP are done versus standard AERONET retrievals. The coherence of day-to-night evolutions of the different aerosol properties retrieved by GRASP is also studied. The extinction coefficient vertical profiles retrieved by GRASP are compared with the profiles calculated by the Raman technique at night-time with differences below 30% for all schemes at 355, 532 and 1064 nm. Finally, the volume concentration and scattering coefficient retrieved by GRASP at 2500ma.s.l. are evaluated by in situ measurements at this height at Sierra Nevada Station. The differences between GRASP and in situ measurements are similar for the different schemes, with differences below 30% for both volume concentration and scattering coefficient. In general, for the scattering coefficient, the GRASP N0 and N1 show better results than the GRASP N2 schemes, while for volume concentration, GRASP N2 shows the lowest differences against in situ measurements (around 10 %) for high aerosol optical depth values.

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  • IPEN-DOC 26652

    LEAO, CLAUDIO ; BUSTILLOS, OSCAR V. . Determination of sodium chloroacetates in cocoamide propyl betaine by gas chromatography: FID, ECD and MS. International Journal of Latest Engineering and Management Research, v. 4, n. 11, p. 90-102, 2019.

    Abstract: This study regards a development of analytical method for determination of sodium monochloroacetate MCAS and sodium dichloroacetate DCAS incocoamidepropyl betaine CAPB by gas chromatography. CAPB is a feedstock for consumer products of the cosmetic and household segments and MCAS and DCAS are toxic, irritating and harmful impurities, so that, low contents are required (parts per million level) in process control of producers and regulatory affairs. To this end, the analytical method developed has: 1) appropriate performance parameters precision, accuracy and low quantification limit; 2) alternative detection modes by flame ionization FID and mass spectrometer MS, since the most conventional electron capture detector ECDrequires government control andqualified radiological protection from manufacturer due radioactive source 63Ni; 3) efficient analyte derivation and separation by employ ethanol and liquid-liquid extraction, respectively. The validation process was applied to ensure a selective, robust, accurate and reproducible analytical determination for the developed methodologies.

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  • IPEN-DOC 26651

    MARTINS, ANDRE L.T.; COUTO, ANTONIO A. ; LIMA, NELSON B. de ; ALMEIDA, GISELE F.C. . Crystallographic texture evolution of aluminum alloy 3104 in the Drawn and Wall Ironing (DWI) process. Materials Research, v. 22, suppl.1, p. 1-6, 2019. DOI: 10.1590/1980-5373-MR-2019-0037

    Abstract: Aluminum beverage cans should have very specific crystallographic textures to increase productivity, reduce losses and reduce the amount of material. The present work seeks to add information on the crystallographic texture of aluminum alloy 3104 H-19 during the different manufacturing steps, which undergoes a flat sheet of metal for a cylindrical body. The work scope encompasses from the cup drawing to the final ironing operation and its objective is to add information on the texture evolution of the aluminum alloy undergoes in the intermediary steps. Crystallographic texture continues to change from the drawn cup through the ironing stages. This rotation is assumed to be a grain alignment with the plastic flow of the material.

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  • IPEN-DOC 26650

    MACHADO, CARULINE de S.C. ; DONATUS, UYIME ; MILAGRE, MARIANA X. ; MOGILI, NAGA V.V.; GIORJÃO, RAFAEL A.R.; KLUMPP, RAFAEL E. ; ARAUJO, JOAO V. de S. ; FERREIRA, RAPHAEL O.; COSTA, ISOLDA . Correlating the modes of corrosion with microstructure in the friction stir welded AA2198-T8 alloy in aqueous hydrogen peroxide-chloride medium. Corrosion, v. 75, n. 6, p. 628-640, 2019. DOI: 10.5006/3054

    Abstract: In this study, different types of localized corrosion in the friction stir welding (FSW) zones of an AA2198-T8 when the alloy is subjected to a corrosion test in a hydrogen peroxide–chloride solution (according to ASTM G110 standard) has been investigated. The corrosion modes were correlated with microstructure, especially with respect to the T1 phase and coarse Al-Cu-Fe phase distribution across the weldment. Simulated thermal profile and microhardness measurements were used to establish the variations in T1 phase distribution. Two types of corrosion were observed in the FSW zones: intense pitting and intergranular corrosion—type I; and the formation of cavities and trenches—type II. Type I is associated with the T1 phase while type II is associated with Al-Cu-Fe coarse intermetallics. Both types were found on the base metal (BM) and heat affected zone, but the type I reduced in the latter toward the stir zone (SZ). The SZ/thermomechanically affected zone (TMAZ) exhibited only type II. Also, Cu enrichment was observed around the type II sites in the SZ/TMAZ. Furthermore, an inverse correlation between microhardness and corrosion resistance which was related to T1 phase concentration in the different zones was also observed. Moreover, the SZ and BM were isolated and evaluated by an immersion test and electrochemical analysis using the ASTM G110 test solution. The results indicated galvanic coupling effects, as the SZ was strongly attacked when exposed separately compared to when it was coupled with the other zones.

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  • IPEN-DOC 26649

    MIRANDA, ANA C.C. ; LOBATO, DENISE R.; ARAUJO, ELAINE B. de . Comparative overview of innovation and patent filings in Radiopharmacy / Panorama comparativo da inovação e do depósito de patentes em Radiofarmácia. einstein (São Paulo), v. 18, p. 1-7, 2020. DOI: 10.31744/einstein_journal/2020GS4816

    Abstract: Objective: To expose the current situation of the Brazilian Nuclear Medicine in relation to innovation, taking into account the Intellectual Property protection and the particularities of this field. Methods: The number and the origin of patents filings from Brazil, United States and European Patent Convention countries were retrospectively compared in a 20-year period. Results: The number of accumulated patents filings of conventional pharmaceuticals was ten times higher compared to the radiopharmaceuticals in the three regions studied. Conclusion: The largest number of Brazilian patents filings corresponded to the international patent applications, which is related to the country development conditions, as well as to the difficulties in the process of patent filing.

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  • IPEN-DOC 26648

    ALMEIDA JUNIOR, JULIO C. de; HELAL-NETO, EDWARD; PINTO, SUYENE R.; SANTOS, SOFIA N. dos ; BERNARDES, EMERSON S. ; AL-QAHTANI, MOHAMMED; NIGRO, FIAMMETTA; ALENCAR, LUCIANA M.R.; RICCI-JUNIOR, EDUARDO; SANTOS-OLIVEIRA, RALPH. Colorectal Adenocarcinoma: imaging using 5-Fluoracil nanoparticles labeled with technetium 99 metastable. Current Pharmaceutical Design, v. 25, n. 30, p. 3282-3288, 2019. DOI: 10.2174/1381612825666190816235147

    Abstract: Background: Adenocarcinoma of colon and rectum are one of the most common cancers worldwide, responsible for over 1,300,000 people diagnosed. Also, they are responsible for metastasis, which leads to death in less than 5 years. Methods: In this study, we developed, characterized, and pre-clinically tested a new nano-radiopharmaceutical for early and differential detection of adenocarcinoma of colon and rectum. Results and Conclusion: Results demonstrated the specificity of the developed nanosystem and the ability to reach the tumor with very specific targeting. Also, the imaging data support the use of this nano-agent as a nanoimaging- guided-radiopharmaceutical.

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  • IPEN-DOC 26647

    BORTOLETTO, LUIZ A.; LIMA, ERICO da S.; FAVARO, DEBORAH I.T. ; ULRICH, JOAO C. ; SOUZA, VANESSA A.F. de; COTRIM, MARYCEL E.B. ; BEZERRA, FERNANDA de C.. Avaliação de metais tóxicos de alfaces cultivadas em horta urbana na cidade de São Paulo, São Paulo / Evaluation of toxic metals in lettuces grown of an urban garden in the city of São Paulo, state of São Paulo, Brazil. Revista Brasileira de Ciências Ambientais, v. 52, p. 99-118, 2019. DOI: 10.5327/Z2176-947820190462

    Abstract: As hortas urbanas trazem benefícios alimentares e sociais, mas os poluentes atmosféricos são nocivos à saúde. Então, surge a questão: os alimentos das hortas urbanas são seguros? Para investigar, neste estudo utilizou-se a alface crespa, a mais consumida em São Paulo e bioindicadora de metais tóxicos. A pesquisa ocorreu de agosto a outubro de 2018, em horta urbana no telhado de um grande shopping da cidade de São Paulo, cercado de intenso tráfego de veículos. Utilizaram-se dois tratamentos, cultivo a céu aberto (T1) e cultivo em estufa com controle de ar (T2), com nove repetições cada. Após 60 dias, quantificaram-se as concentrações médias, nas amostras, dos elementos arsênio (As), cádmio (Cd), cromo (Cr), chumbo (Pb) e zinco (Zn), que não ultrapassaram os limites máximos preconizados pela Agência Nacional de Vigilância Sanitária (ANVISA). Concluiu-se que as alfaces não oferecem riscos à saúde humana, e o tratamento T2 reduziu o teor de Zn na alface (p<0,05).

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  • IPEN-DOC 26621

    PASQUALINI, ALEXANDRE A. ; IRAZUSTA, SILVIA P.; ARTHUR, VALTER; BALSAMO, PAULO J.. Avaliação da radiação ioniante em ovários de Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) através da técnica do cometa / Ionian radiation evaluation in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) ovaries through the comet technique. Revista Faculdades do Saber, v. 4, n. 7, p. 466-471, 2019.

    Abstract: Este trabalho avaliou os efeitos genotóxicos em tecidos ovarianos de ácaros do gênero Rhipicephalus (Boophilus) microplus, um carrapato que infesta, preferencialmente, bovinos com o intuito de aprimorar conhecimentos para se adaptar à técnica do inseto estéril como um meio de controle populacional deste parasita. Fêmeas ingurgitadas de sangue e em fase de pré postura foram irradiadas com doses de 0, 5, 10, 15, 20 e 25 Gy com Cobalto-60 e dentro de 24 horas foram dissecadas e seus ovários formaram uma amostra pool com os quais foi realizado o teste do cometa e a genotoxicidade inferida nestes tecidos foi proporcional ao aumento das doses ionizantes.

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  • IPEN-DOC 26620

    LEAL, GEORGIA B. ; SILVA, DANIELA C.L. da ; WATACABE, BEATRIZ N. ; CIOTTI, LIGIA ; ANTONIASSI, RODOLFO M. ; GIUDICI, REINALDO; LINARDI, MARCELO ; VAZ, JORGE M. ; SPINACE, ESTEVAM V. . Au/TiO2 catalysts prepared by borohydride reduction for preferential CO oxidation at near-ambient temperature. Catalysis for Sustainable Energy, v. 6, n. 1, p. 6-12, 2019. DOI: 10.1515/cse-2019-0002

    Abstract: Au nanoparticles were prepared in solution using HAuCl4.3H2O as Au precursor, sodium citrate as stabilizing agent and sodium borohydride as reducing agent. The influence of synthesis parameters such as BH4:Au and Citrate:Au ratios were studied. In a further step, the stabilized Au nanoparticles were supported on TiO2 with different Au loadings (wt%). The resulting Au/ TiO2 catalysts were characterized by Energy-dispersive X-ray spectroscopy, X-ray diffraction and Transmission Electron Microscopy and tested for the preferential oxidation of carbon monoxide in hydrogen-rich stream. Au nanoparticles stabilized in solution were obtained with sizes in the range of 3-4 nm. After supported on TiO2, the Au nanoparticles size did not change and the Au/TiO2 catalysts exhibited excellent performance and stability in the temperature range of 20 - 50 °C.

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  • IPEN-DOC 26619

    NANDENHA, J. ; NAGAHAMA, I.H.F. ; YAMASHITA, J.Y. ; FONTES, E.H. ; AYOUB, J.M.S. ; SOUZA, R.F.B. de ; FONSECA, F.C. ; NETO, A.O. . Activation of methane on PdZn/C electrocatalysts in an acidic electrolyte at low temperatures. International Journal of Electrochemical Science, v. 14, n. 12, p. 10819-10834, 2019. DOI: 10.20964/2019.12.76

    Abstract: PdZn/C electrocatalysts were prepared by sodium borohydride utilized as reducing agent for activation methane in an acidic medium at room temperature and in a proton exchange membrane fuel cell (PEMFC) at 80°C. The materials prepared were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The diffractograms of the PdZn/C electrocatalysts showed only peaks associated with Pd face-centered cubic (fcc) structure. Cyclic voltammograms (CV) of all electrocatalysts after adsorption of methane shown an increment in current during the anodic scan, this effect was more pronounced for Pd(70)Zn(30)/C. In situ ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) experiments was not observed the formation of intermediates adsorbed for PdZn/C electrocatalysts, this behavior indicated that the methane oxidation occurs by parallel mechanisms. Polarization curves at 80°C in PEMFC show that Pd(90)Zn(10)/C has superior performance over the other electrocatalysts in methane oxidation.

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  • IPEN-DOC 26646

    SILVA, J.P.L. ; TEIXEIRA, L.F. ; BELLINI, M.H. . [6]-Gingerol decreases clonogenicity and radioresistance of human prostate cancer cells. Clinical Oncology and Research, v. 2, n. 5, p. 1-3, 2019. DOI: 10.31487/j.COR.2019.05.07

    Abstract: The phenolic compound [6]-Gingerol, isolated from Zingiber officinale, has been demonstrated to have antitumor activity for different types of malignant tumours. Prostate cancer is the most common malignancy among males worldwide, being the second leading cause of cancer death in men. In the present study, we investigated the antitumor action of [6]-Gingerol on a human prostate cancer cell line (LNCaP). Our data shows that [6]-Gingerol treatment induced a dose-dependent decrease in the cell viability. Compared with the vehicle control, the cell viabilities were 79.90 ± 3.56% and 53.06 ± 7.82% when the LNCaP cells were exposed to 150 μg/mL and 300 μg/mL of [6]-Gingerol, respectively. The treatment of LNCaP with 300 μM of [6]-Gingerol led to a significant reduction (~25%) on the clonogenic survival of these cells. Furthermore, [6]-gingerol acted as a radiosensitizer for LNCaP cells. The pretreatment of these cells with [6]-Gingerol significantly enhanced the killing effects of ionizing radiation with a dose enhancement ratio of 1.25. Our results demonstrate the anti-tumour activities of [6]-Gingerol. Further studies are needed to elucidate the mechanisms involved.

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  • IPEN-DOC 26645

    BONFIM, LETICIA ; PASSOS, PRISCILA de Q.S. ; GONÇALVES, KARINA de O.; COURROL, LILIA C.; SILVA, FLAVIA R. de O. ; VIEIRA, DANIEL P. . Microwave-mediated synthesis of iron-oxide nanoparticles for use in magnetic levitation cell cultures. Applied Nanoscience, v. 9, n. 8, p. 1707-1717, 2019. DOI: 10.1007/s13204-019-00962-1

    Abstract: The use of three-dimensional cell cultures has been widely used for efficacy and/or toxicity testing of compounds. One of the most promising systems, based on magnetic levitation, is dependent on proper cell magnetization, achieved through adsorption of iron-oxide nanoparticles on cell membranes. These particles must bare not only significant responses to magnetic fields, but also a stable mechanism to attachment to cells. This work proposes a simple, one-pot synthesis method to produce magnetite nanoparticles, using a Fe2+ precursor associated with amino acids under microwave heating, and successive steps to confer positive charges to particles. X-ray diffraction could confirm Fe3O4 composition, and TEM analysis showed cubic-like crystallites with less than 50 nm. Zeta-potential experiments showed that particles remained positively charged (20.98 ± 0.28 mV) in physiological pH, suggesting ability to attach to (negatively charged) cell membranes, observed through optical microscopy. Iron colloid was found to be non-cytotoxic in concentrations up to 8% in cell culture media. Finally, human prostate cancer cells were cultured in 96-well plates using magnetic levitation and could be kept 8 days in culture. The results showed a feasible way to produce spheroids relying on magnetic levitation, using a newly described method of magnetic and cell adherent nanoparticle production.

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  • IPEN-DOC 26644

    DONATUS, UYIME ; SILVA, REJANE M.P. da ; ARAUJO, JOAO V. de S. ; MILAGRE, MARIANA X. ; ABREU, CAIO P. de ; MACHADO, CARULINE de S.C. ; COSTA, ISOLDA . Macro and microgalvanic interactions in friction stir weldment of AA2198-T851 alloy. Journal of Materials Research and Technology, v. 8, n. 6, p. 6209-6222, 2019. DOI: 10.1016/j.jmrt.2019.10.015

    Abstract: The galvanic interactions within and between the friction stir weld zones of the AA2198-T851alloy have been investigated using electrochemical and microscopy techniques. The parentmaterial (PM) was the most anodic region and exhibited pronounced severe localized corro-sion (SLC) both when coupled and isolated. The stir zone was the most resistant to corrosionand exhibited no SLC when coupled, but exhibited SLC when isolated. Profiles associatedwith dissolved oxygen consumption and hydrogen generation currents across the weldmentwere inversely related because the anodic (PM) region produced higher hydrogen bubblesand, interestingly, consumed more dissolved oxygen compared with the other regions.

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  • IPEN-DOC 26643

    MILAGRE, MARIANA X. ; DONATUS, UYIME ; MACHADO, CARULINE S.C. ; ARAUJO, JOAO V.S. ; FERREIRA, RAPHAEL O.; SILVA, REJANE M.P. ; ANTUNES, RENATO A.; COSTA, ISOLDA . Exfoliation corrosion susceptibility in the zones of friction stir welded AA2098-T351. Journal of Materials Research and Technology, v. 8, n. 6, p. 5916-5929, 2019. DOI: 10.1016/j.jmrt.2019.09.066

    Abstract: In the present study, the exfoliation susceptibility of the weld zones in friction stir weldedAA2098-T351 was compared with that of the base metal (BM) according to ASTM G34 stan-dard practice. Friction stir welding (FSW) had a significant effect on the microstructure of theAl alloy tested and the susceptibility to exfoliation was strongly affected by the microstruc-ture. Different features of corrosion attack and exfoliation susceptibility were observed whenthe zones affected by FSW were tested isolated or coupled. Also, the near-surface deformedlayer had an important effect on the Al alloy susceptibility to exfoliation. These are themain findings of this work. The corrosion features were correlated with the microstructuralmodifications related to the welding process and with the electrochemical response. TheT1 phase morphology, distribution and size were critical for exfoliation susceptibility. Thestir zone (SZ) was the zone most resistant to exfoliation. However, resistance to exfoliationvaried with the temperatures reached in the heat affected zones (HAZs). The HAZ exposedto the lowest temperatures during welding, HAZ (LT), was the most susceptible to exfoli-ation, whereas the HAZ exposed to the highest temperatures, HAZ (HT), presented highresistance to exfoliation, similarly to the SZ. The ASTM-G34 practice was an effective anduseful method in identifying the different exfoliation resistances of the BM and the vari-ous zones affected by FSW. The results of this practice were supported by electrochemicalimpedance spectroscopy (EIS) tests.

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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.

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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 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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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

    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.

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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.

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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.

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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.

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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.

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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.

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A pesquisa no RD utiliza os recursos de busca da maioria das bases de dados. No entanto algumas dicas podem auxiliar para obter um resultado mais pertinente.

É possível efetuar a busca de um autor ou um termo em todo o RD, por meio do Buscar no Repositório , isto é, o termo solicitado será localizado em qualquer campo do RD. No entanto esse tipo de pesquisa não é recomendada a não ser que se deseje um resultado amplo e generalizado.

A pesquisa apresentará melhor resultado selecionando um dos filtros disponíveis em Navegar

Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

A opção Busca avançada utiliza os conectores da lógica boleana, é o melhor recurso para combinar chaves de busca e obter documentos relevantes à sua pesquisa, utilize os filtros apresentados na caixa de seleção para refinar o resultado de busca. Pode-se adicionar vários filtros a uma mesma busca.

Exemplo:

Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).

ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

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.

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.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.