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  • IPEN-DOC 25729

    GUILHEN, SABINE N. ; ROVANI, SUZIMARA ; PITOL FILHO, LUIZILDO; FUNGARO, DENISE A. . Kinetic study of uranium removal from aqueous solutions by macaúba biochar. Chemical Engineering Communications, v. 206, n. 11, p. 1365-1377, 2019. DOI: 10.1080/00986445.2018.1533467

    Abstract: Macaúba (Acronomia aculeata) is a palm tree native of the Brazilian savanna and a valuable renewable source of vegetable oil for human consumption and biodiesel production. In this study, the potentiality of the macaúba endocarp for biochar (BC) production was demonstrated. Moisture, density, elemental and molecular composition, along with TGA, FTIR, and XRD analyses were performed for the endocarp. Adsorption of uranyl ions, U(VI), from aqueous solutions was studied by batch technique using BC produced by slow pyrolysis of the endocarp at 350 °C (BC350). The effect of contact time on the removal of U(VI) by BC350 was evaluated. Linear and non-linear kinetics models were employed and the best fit for the experimental data was achieved for pseudo-first order non-linear model. The adsorption equilibrium was attained after 180 min of contact time and the equilibrium adsorption capacity achieved was of 400mg g-1. Finally, BC350 was characterized by SEM, FTIR, WDXRF, and XRD techniques.

    Palavras-Chave: kinetics; uranium; aqueous solutions; adsorption; trees; coconut palms; carbon; pyrolytic carbon

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  • IPEN-DOC 25934

    ARAUJO, JOAO V. de S. ; BUGARIN, ALINE de F.S. ; DONATUS, UYIME ; MACHADO, CARULINE de S.C. ; QUEIROZ, FERNANDA M. ; TERADA, MAYSA ; ASTARITA, ANTONELLO; COSTA, ISOLDA . Thermomechanical treatment and corrosion resistance correlation in the AA2198 Al–Cu–Li alloy. Corrosion Engineering, Science and Technology, v. 54, n. 7, p. 575-586, 2019. DOI: 10.1080/1478422X.2019.1637077

    Abstract: The influence of T3, T8 and T851 thermomechanical treatments on the microstructure and corrosion resistance of the AA2198 was investigated. Differential scanning calorimetry and scanning electron microscopy were used for microstructural characterisation, whereas electrochemical methods were employed to analyse the corrosion behaviour of the alloy. The morphology and composition of constituent particles were similar for the T3 and T8 thermomechanical treatments but varied in the T851. There was an inverse relation between T1 phase density and corrosion resistance. The T3 treatment with the highest corrosion resistance was the one with the lowest density of T1 phase. The mechanisms of corrosion varied with the thermomechanical treatments.

    Palavras-Chave: thermomechanical treatments; aluminium alloys; lithium alloys; microstrutura; copper alloys; corrosion resistant alloys; heat treatments

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  • IPEN-DOC 25933

    OLIVEIRA, PATRICIA da S.P. de ; ANDREA, VINICIUS ; SANTIAGO, ELISABETE I. ; LOPES, THIAGO ; ANDRADE, DELVONEI A. de ; LINARDI, MARCELO . A reliability-based strategy for the analysis of single proton exchange membrane fuel cells. Energy and Power Engineering, v. 11, n. 8, p. 303-319, 2019. DOI: 10.4236/epe.2019.118019

    Abstract: The development of power conversion systems based on fuel cells has been demanding reliability studies since the requirements associated with cost and durability of these technological products have become fundamental to their acceptance by the energy market. The experimental part of the reliability study presented in this work consisted of performing life tests with single proton exchange membrane fuel cells (PEMFCs). The proposed reliability analysis methodology covered the application of qualitative and quantitative techniques. In the qualitative approach, a Failure Mode and Effect Analysis was developed in order to identify and evaluate all potential failures associated with the operation of fuel cells. In the quantitative approach, a statistical analysis was applied to the sample data generated in long-term steady-state tests of these devices. A two-parameter exponential distribution was fitted to data and the maximum likelihood estimate for the mean time to failure (MTTF) of the fuel cells was calculated. It is important to point out that the tests performed under the scope of this study were the first long-term experiments performed with the fuel cells produced in the laboratories of IPEN-CNEN/SP, Brazil. Although the results indicated that fuel cell performance and durability were still at a level below the targets normally established for similar commercial devices, the improvement of the main components of PEMFCs has been the objective of several projects developed at the institute. Thus, the main benefit brought by this study is the proposed methodology, which can be implemented as part of a reliability growth analysis of the fuel cells and can be integrated into the design process of these devices.

    Palavras-Chave: fuel cells; reliability; durability; lifetime; energy; failures; hydrogen; brazilian cnen

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  • IPEN-DOC 25915

    SILVA, M.R.M. ; FIM, R.G.T. ; SILVA, S.C. ; CASINI, J.C.S.; WENDHAUSEN, P.A.P.; TAKIISHI, H. . Influence of alloying elements Zr, Nb and Mo on the microstructure and magnetic properties of sintered Pr-Fe-Co-B based permanent magnets. Materials Science Forum, v. 930, p. 440-444, 2018. DOI: 10.4028/www.scientific.net/MSF.930.440

    Abstract: The addition of alloying elements on rare-earth permanent magnets is one of the methods used to improve the magnetic properties. This present work evaluates the influence of alloying elements such as Zr, Nb and Mo on the microstructure and magnetic properties of sintered Pr-FeCo- B based permanent magnets. The permanent magnets were produced by the conventional powder metallurgy route using powder obtained by hydrogen-decrepitation (HD) method from as cast alloys. In order to produce the magnet Pr16Fe66,9Co10,7B5,7Cu0,7 without alloying elements the mixture of alloys method was employed, mixing two compositions: Pr20Fe73B5Cu2 (33% w.t) and Pr14Fe64Co16B6 (67% w.t). With the purpose of evaluating the influence of the alloying elements, the Pr14Fe64Co16B6X0,1 (where X= Zr, Nb or Mo) (67% w.t) alloy was employed. The characterization of the alloys and the magnets was carried out using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS) and the magnetic properties were measured using a permeameter. The magnet without any additions presented the highest intrinsic coercivity (0iHc = 748 KA.m-1) while the magnet with Nb addition presented higher remanence (Br = 1,04 T). The magnet with Zr addition presented the highest maximum energy product (BHmáx = 144 KJ.m-3), and the magnet with Mo addition showed the highest squareness factor (SF = 0,73).

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  • IPEN-DOC 25914

    FIM, R.G.T. ; SILVA, M.R.M. ; SILVA, S.C. ; CASINI, J.C.S.; WENDHAUSEN, P.A.P.; TAKIISHI, H. . Influence of milling time on magnetic properties and microstructure of sintered Nd-Fe-B based permanent magnets. Materials Science Forum, v. 930, p. 445-448, 2018. DOI: 10.4028/www.scientific.net/MSF.930.445

    Abstract: In this paper, the effect of the grain size on sintered Nd-Fe-B based permanent magnets was investigated. In order, the magnets were produced by different milling times at 200 rpm and then vacuum sintered at 1373 K for 60 minutes followed by cooling outside the furnace. The magnets either produced by lower and higher milling times (30 and 75 minutes) exhibited lower remanence and coercivity, due the inhomogeneous distribution of the grain sizes. The magnet produced by intermediary milling time (45 minutes) exhibited the highest properties among all samples, with remanence of 1.06 T, coercivity of 891.3 KA.m-1, maximum energy product of 211 KJ.m3 and a squareness factor equal 0.92.

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  • IPEN-DOC 25893

    CARVALHO, PATRICIA R. ; MUNITA, CASIMIRO S. . Estudos arqueométricos de cerâmicas sul-americanas. Revista da Universidade Ibirapuera, v. 16, p. 52-62, 2018.

    Abstract: As análises realizadas neste trabalho têm como objetivo contribuir com a discussão sobre os materiais utilizados na fabricação, a tecnologia de produção e a idade de objetos cerâmicos de antigas civilizações sul- -americanas. Para isso, quarenta e seis fragmentos de cerâmica de cinco sítios arqueológicos de Cusco, Peru, foram analisados utilizando INAA para determinar a fração de massa de 20 elementos químicos (Na, K, La, Nd, Sm, Yb, Lu, U, Sc, Cr, Fe, Co, Rb, Cs, Ce, Eu, Tb, Hf, Ta e Th). Três métodos estatísticos multivariados, análise de agrupamentos, análise discriminante e gráfico bivariado, foram aplicados no conjunto de dados. Pela análise de agrupamentos encontraram-se três grupos de amostas de composição química similar, os quais, por meio da análise discriminante e do gráfico bivariado, foi possível confirmar que foram classificados corretamente. Os resultados mostram que as amostras foram fabricadas com 3 diferentes fontes de matéria- -prima. O estudo da datação por TL mostrou que os três grupos de amostras estão de acordo com os três períodos do Império Inca. Ademais, o estudo da temperatura de queima realizada pela EPR mostrou que era inferior a 600 °C.

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  • IPEN-DOC 25880

    BORDON, ISABELLA C.; CAMPOS, BRUNO G. de; GUSSO‑CHOUERI, PALOMA K.; MIYAI, CAIO A.; ARAUJO, GIULIANA S. de; EMERENCIANO, ANDREWS K.; SILVA, JOSE R.M.C. da; COTRIM, MARYCEL E.B. ; FAVARO, DEBORAH I.T. ; ABESSA, DENIS M. de S.. Improvements in metal exposure assays: artificial food to assess bioaccumulation in the blue crab Callinectes danae Smith, 1869 (Crustacea, Decapoda, Portunidae). International Journal of Environmental Research, v. 13, n. 2, p. 431-434, 2019. DOI: 10.1007/s41742-019-00170-3

    Abstract: This technical note aims to report, in detail, the development, suitability and analytical validation of an artificial food to assess metal bioaccumulation in the blue crab Callinectes danae after metal exposure assays. For this purpose, lead (Pb) was chosen as the metal of interest. First, a non-contaminated artificial food was prepared by mixing commercial shrimps and agarose. The food was then offered on alternate days to two groups of crabs for 7 and 14 days, respectively. After confirming that this food was well-accepted by crabs, analytical procedures were performed to confirm that Pb added to the mixture would remain in the artificial food. For this purpose, two foods containing Pb at concentrations of 0.5 and 2.0 μg g− 1 were prepared by adding aliquots of an ultrapure Pb standard solution to the mixture. Samples of each food were subjected to an acid extraction and Pb concentrations were determined by a GF-AAS. Pb recoveries in both contaminated foods were > 90%. Subsequently, another experiment was performed, and two groups of crabs were fed with contaminated artificial foods (0.5 and 2.0 μg g− 1 of Pb) during 7 and 14 days, respectively. The observed acceptance of these foods by crabs at both Pb concentrations was of 100%.

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  • IPEN-DOC 25790

    SIMÕES, MARTA F.; MAIORANO, ALFREDO E.; SANTOS, JONAS G. dos; PEIXOTO, LUCIANA; SOUZA, RODRIGO F.B. de ; OLIVEIRA NETO, ALMIR ; BRITO, ANTONIO G.; OTTONI, CRISTIANE A.. Microbial fuel cell‑induced production of fungal laccase to degrade the anthraquinone dye Remazol Brilliant Blue R. Environmental Chemistry Letters, v. 17, n. 3, p. 1413-1420, 2019. DOI: 10.1007/s10311-019-00876-y

    Abstract: The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods have been tested to solve this ecological problem, but there is still a need for efficient methods. We propose here an alternative use of a two-chambered microbial fuel cell (MFC), fuelled with domestic wastewater in the anodic chamber, to degrade a simulated textile dye effluent made of Remazol Brilliant Blue R inoculated with an immobilised fungal strain, Pleurotus ostreatus URM 4809, as a laccase producer, in the cathodic chamber. The MFC showed continuous synthesis of laccase in the cathodic chamber, which, in turn, promoted the rapid decolourisation, of more than 86% of the textile dye effluent. The yield was further increased by the addition of glycerol. Electrochemical monitoring also indicated an increase in power density and current density. After 20 days of MFC operation, 62.1% of organic matter was removed in the anodic compartment, thus leaving the effluent with a much lower toxicity.

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  • IPEN-DOC 25873

    ESCANHOELA, CORDELIA M.F.; SABUNDJIAN, GAIANE ; LIMA, ANA C. de S. . Educação ambiental e sustentabilidade: um reator nuclear inovador para o Brasil. Revista Mais Educação, v. 2, n. 2, p. 220-229, 2019.

    Abstract: Este trabalho apresenta um estudo sobre a implementação do reator inovador System - Integrated Modular Advanced Reactor (SMART) no Brasil. Desenvolvido pelo Korea Atomic Energy Research Institute (KAERI) e com potência elétrica de 100MWe, esse reator pode atender a uma demanda de cerca de 100.000 habitantes. A escolha deste reator nuclear inovador está alicerçada, primeiramente, na análise do cenário energético nacional, no qual é demonstrada tanto a necessidade da expansão energética no Brasil quanto na imprescindível escolha de fontes alternativas de energia de maneira a atender as exigências de sustentabilidade e atenuação dos impactos ambientais. Dentro do contexto de complementariedade da matriz energética nacional associada à descentralização da geração de energia elétrica; o projeto envolvendo um reator nuclear pequeno e modular do tipo Power Water Reactor (PWR) prova ser uma escolha assertiva inclusive do ponto de vista econômico, já comprovado por meio de métodos econômicofinanceiros e ainda, pelo aproveitamento da expertise existente no país.

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  • IPEN-DOC 25870

    SELLERA, FABIO P.; DUTRA, GUSTAVO H.P.; NASCIMENTO, CRISTIANE L.; RODRIGUES, FERNANDA P.; SÁ, LILIAN R.M. de; ALMEIDA-LOPES, LUCIANA; RIBEIRO, MARTHA S. ; POGLIANI, FABIO C.. Investigation of green turtle (Chelonia mydas) cutaneous fibropapillomatosis recurrence rates following diode laser surgery. Journal of Exotic Pet Medicine, v. 28, n. C, p. 180-184, 2019. DOI: 10.1053/j.jepm.2018.10.010

    Abstract: A pilot study was performed to investigate fibropapillomatosis (FP) recurrence rates after 940 nm-diode laser surgeries. Fifteen animals had a total of 274 tumors removed by diode laser. Cutaneous FP recurrence rates were evaluated during a period of 1-year. According to tumor sizes classification, 166 tumors (60.6%) were <1 cm, 67 tumors (24.5%) between 1-4 cm, 31 tumors (11.3%) >4-10 cm and 10 tumors (3.6%) >10 cm. Seven animals (46.6%) were lightly afflicted, 4 (26.7%) moderately, and 4 (26.7%) heavily afflicted. Thirteen animals (86.7%) did not present tumor regrowth and 2 (13.3%) presented small tumors after 1-year.

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  • IPEN-DOC 25869

    SOUZA, ARMANDO C. de; ROSSI, JESUALDO L. ; CIONE, FRANCISCO C. ; MACHADO, NOE G.P. ; SILVA, ALINE C. da; SILVA, WALLACE F. da. Study of a metal-organic composite (Wx%Lig) for the gamma radiation attenuation. Research & Reviews: Journal of Material Sciences, v. 6, n. 4, p. 238-243, 2018. DOI: 10.4172/2321-6212.1000239

    Abstract: The objective of this work was to use tungsten and lignin as precursors to produce a metal-organic composite (Wx%Lig) using different sintering processes. Tungsten is a refractory metal and was selected for the composite due to its superior physical and mechanical properties (mechanical strength, high melting point, and excellent cross section with thermal neutrons). Its choice is also justified because it is widely used for high-energy radiation shielding. Lignin extracted from lignocellulosic biomass was selected to be the organic precursor for the composite because it has multiple applications; it is used in the production of aromatics, adhesives, and as a phenolic resin replacement. Analysis of the composite was performed after sintering processes using a Nexview 3D optical surface profiler and analyse the gamma radiation attenuation coefficient using cobalt source (Co-60). Metal-organic composites in ratios of W5%Lig and W2.5%Lig were produced after different heat treatment processes. Then, the gamma attenuation coefficients of the composite samples in these rations were analysing. The gradient of the attenuation coefficient differed when standard tungsten and the composites of W5%Lig and W2.5%Lig were compared with free source Co-60.

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  • IPEN-DOC 25868

    TEITELBAUM, SUSANA; ANDRADE, DELVONEI A. de ; PAREDES, WILBER E.B. . Perfil de pacientes oncológicos tratados con láser de baja intensidad. Dental Tribune Hispanic & Latin America, v. 15, n. 3, p. 14-19, 2018.

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  • IPEN-DOC 25867

    SILVA, J.O.; CALDAS, L.V.E. . Performance tests of a special ionization chamber for X-rays in mammography energy range. Brazilian Journal of Radiation Sciences, v. 6, n. 2A, p. 1-14, 2018. DOI: 10.15392/bjrs.v6i2%20-%20A.501

    Abstract: A special mammography homemade ionization chamber was developed to be applied for mammography energy range dosimetry. This chamber has a total sensitive volume of 6 cm³ and is made of a PMMA body and graphite coated collecting electrode. Performance tests as saturation, ion collection efficiency, linearity of chamber response versus air kerma rate and energy dependence were determined. The results obtained with this special homemade ionization chamber are within the limits stated in international recommendations. This chamber can be used in quality control programs of mammography energy range. All measurements were carried out at the Calibration Laboratory of IPEN.

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  • IPEN-DOC 25866

    BUSTILLOS, OSCAR V. . A ionização química como fonte de íons na espectrometria de massas. Revista Analytica, v. 17, n. 98, p. 34-35, 2019.

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  • IPEN-DOC 25865

    BUSTILLOS, OSCAR V. . A técnica de ionização por Electrospray na espectrometria de massas. Revista Analytica, v. 17, n. 99, p. 32-33, 2019.

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  • IPEN-DOC 25864

    GONÇALVES, LIVIA de S.; FRANCHI, MARIANA; MATHOR, MONICA B. ; LUGAO, ADEMAR B. ; CARVALHO, VICTOR H.; MEDEIROS, MARISA H.G.; ARTIOLI, GUILHERME G.; VARCA, GUSTAVO H.C. . The molecular structure of β-alanine is resistant to sterilising doses of gamma radiation. PLoS One, v. 14, n. 1, p. 1-13, 2019. DOI: 10.1371/journal.pone.0210713

    Abstract: β-alanine is the rate-limiting point for the endogenous synthesis of carnosine in skeletal muscle. Carnosine has a wide range of implications for health, normal function and exercise performance. Whilst the physiological relevance of carnosine to different tissues remains enigmatic, β-alanine administration is a useful strategy to investigate the physiological roles of carnosine in humans. Intravenous administration of β-alanine is an interesting approach to study carnosine metabolism. However, sterilisation is mandatory due to the nature of the administration route. We evaluated whether sterilising doses of gamma radiation damages the molecular structure and leads to the loss of functional characteristics of β-alanine. Pure β-alanine was sterilised by gamma radiation in sealed glass vials using a 60Co multipurpose irradiator at a dose rate of 8.5 kGy.hour-1 totalising 10, 20, 25 30 and 40 kGy. The molecular integrity was assessed by X-ray Diffraction and changes in content were determined by High Performance Liquid Chromatography (UV-HPLC) and Triple Quadrupole Mass Spectrometer (HPLC/MS-MS). Sterility assurance was evaluated by inoculation assay. To examine whether functional properties were preserved, β-alanine was infused in one participant, who rated the level of paraesthesia on the skin using a 0–3 scale. Urinary β-alanine was quantified before and 24-h following β-alanine infusion using HPLC-ESI+-MS/MS. Irradiation resulted in no change in the crystal structure of β-alanine, no degradation, and no new peaks were identified in the dose range assayed. The inoculation assay showed the absence of viable microorganisms in all β-alanine samples, including those that did not undergo irradiation. Intravenous infusion of β-alanine resulted in paraesthesia and it detected in the urine as per normal. We conclude that gamma radiation is a suitable technique for the sterilisation of β-alanine. It does not lead to degradation, damage to the β-alanine structure, content or loss of function within the evaluated irradiation conditions.

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  • IPEN-DOC 25863

    CHURA-CHAMBI, ROSA M. ; SILVA, CLEIDE M.R. da ; PEREIRA, LENNON R.; BARTOLINI, PAOLO ; FERREIRA, LUIS C. de S.; MORGANTI, LIGIA . Protein refolding based on high hydrostatic pressure and alkaline pH: application on a recombinant dengue virus NS1 protein. PLoS One, v. 14, n. 1, p. 1-14, 2019. DOI: 10.1371/journal. pone.0211162

    Abstract: In this study we evaluated the association of high hydrostatic pressure (HHP) and alkaline pH as a minimally denaturing condition for the solubilization of inclusion bodies (IBs) generated by recombinant proteins expressed by Escherichia coli strains. The method was successfully applied to a recombinant form of the dengue virus (DENV) non-structural protein 1 (NS1). The minimal pH for IBs solubilization at 1 bar was 12 while a pH of 10 was sufficient for solubilization at HHP: 2.4 kbar for 90 min and 0.4 kbar for 14 h 30 min. An optimal refolding condition was achieved by compression of IBs at HHP and pH 10.5 in the presence of arginine, oxidized and reduced glutathiones, providing much higher yields (up to 8-fold) than association of HHP and GdnHCl via an established protocol. The refolded NS1, 109 ± 9.5 mg/L bacterial culture was recovered mainly as monomer and dimer, corresponding up to 90% of the total protein and remaining immunologically active. The proposed conditions represent an alternative for the refolding of immunologically active recombinant proteins expressed as IBs.

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  • IPEN-DOC 25706

    VERRIJSSEN, AN-SOFIE; OPBROEK, THIRZA; BELLEZZO, MURILLO ; FONSECA, GABRIEL P.; VERHAEGEN, FRANK; GERARD, JEAN-PIERRE; MYINT, ARTHUR S.; LIMBERGEN, EVERT J.V.; BERBEE, MAAIKE. A systematic review comparing radiation toxicity after various endorectal techniques. Brachytherapy, v. 18, n. 1, p. 71-86, 2019. DOI: 10.1016/j.brachy.2018.10.001

    Observação: Corrigendum anexado. Brachytherapy, v. 18, p. 427, 2019. DOI: 10.1016/j.brachy.2018.10.001

    Abstract: PURPOSE: A clinical complete response is seen after neoadjuvant chemoradiation for rectal tumors in 15%e20% of patients. These patients can potentially be spared mutilating total mesorectal excision surgery through a watch-and-wait policy. Recent studies show that dose escalation by a radiation boost increases the clinical complete response rate. The boost dose to the tumor can be administered through external beam radiotherapy or through internal radiotherapy using techniques like contact therapy, low-dose-rate or high-dose-rate brachytherapy (BT). However, limited information is available concerning treatment-related toxicity of these techniques. With this systematic review, we aim to summarize and compare published data concerning acute and late toxicity after contact X-ray therapy (CXT) and BT for rectal cancer. METHODS AND MATERIALS/RESULTS: Thirty-eight studies reporting toxicity after endorectal radiation techniques for rectal cancer were included, resulting in 3682 patients for analysis. Direct comparison of toxicity by the different radiation modes was hampered by various combinations of endorectal techniques, a lack of clear reporting of toxicity scores, dose prescription, technique used, and treated volumes. $ Grade 3 rectal toxicity was reported in 2.9% of patients having received only CXT; 6.3% of patients who received only BT had Grade 3 rectal toxicity, and BT also caused Grade 3 urinary toxicity in 1 patient. CONCLUSION: All techniques reported some$Grade 3 toxicity. Toxicity after CXTwas confined to the rectum, whereas after BT, urogenital toxicity and skin toxicity were seen as well. Unfortunately, few specific conclusions could be drawn regarding the dose-related risk of toxicity for the various techniques due to nonuniform reporting strategies and missing information. To enable future comparisons and improvements, the endorectal radiation field urgently needs consensus guidelines on dose reporting, dose prescription, treatment volume specification, and toxicity reporting. 2018 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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  • IPEN-DOC 25860

    PARREIRA, LUANNA S.; ANTONIASSI, RODOLFO M. ; FREITAS, ISABEL C.; OLIVEIRA, DANIELA C. de; SPINACE, ESTEVAM V. ; CAMARGO, PEDRO H.C.; SANTOS, MAURO C. dos. MWCNT-COOH supported PtSnNi electrocatalysts for direct ethanol fuel cells: low Pt content, selectivity and chemical stability. Renewable Energy, v. 143, p. 1397-1405, 2019. DOI: 10.1016/j.renene.2019.05.067

    Abstract: PtSnNi electrocatalysts (60: 40: 40 mass ratio) supported on Vulcan® XC-72 (Cabot) carbon and COOHfunctionalized multiwalled carbon nanotubes (Cheaptubes®) with 15% of metal loading were prepared. The nanoparticles size of 2e3 nm for both supports was estimated by HRTEM. In the direct ethanol fuel cell experiments, PtSnNi/C presents 50 mA cm 2 reaching the maximum power density (MPD) of 12mWcm 2 and decreasing at higher currents, while PtSnNi/MWCNT-COOH obtains similar values of MPD (60 mA cm 2), but keeping the best performance. By GC (gas chromatography) technique, it was possible to observe that the electrocatalyst supported on MWCNT-COOH favored the ethanol oxidation to acetaldehyde and acetic acid, although the material supported on Vulcan® XC-72 carbon presented almost 100% of selectivity for acetaldehyde. This behavior was maintained also when the current of 0.1 A was applied for 80 min. For the PtSnNi/C electrocatalyst, the selectivity to only acetaldehyde can be related to Sn and Ni dissolution process that can become the electrocatalytic activity similar to Pt/C, decreasing the power density as observed in our experiments. Established by EDS analysis, after 80 min of polarization, the Ni and Sn relative atomic ratio was lower on the catalytic anodic layer of PtSnNi/C than on PtSnNi/MWCNT-COOH.

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  • IPEN-DOC 25859

    POZZO, LORENA ; MONTEIRO, LUCILENA R. ; CERCI, JULIANA J.; FANTI, STEFANO; NEGRO, ANTONELLA; TRINDADE, EVELINDA. HTA in nuclear medicine: [Ga-68]PSMA PET/CT for patients with prostate cancer. Clinical and Translational Imaging, v. 7, n. 1, p. 7-20, 2019. DOI: 10.1007/s40336-019-00313-8

    Abstract: The [ 68Ga]PSMA PET/CT has been an option on clinical research tools to stage and to restage prostate cancer patients, although, with promising results, this radiopharmaceutical cannot be commercialized yet. Hence, up to date, [ 68Ga]PSMA has been used in a clinical research context. Once regulatory body approved it for marketing, health systems are responsible for the reimbursement decision. Health Technology Assessments (HTA) tools should be considered to base and to help decision-makers to spread or not this new technology. Regarding [ 68Ga]PSMA, under HTA framework, the present study searched for secondary studies and hence assessed three systematic reviews with meta-analyses published considering prostate cancer patients in different scenarios, same imaging technology but different comparators and outputs. The secondary studies considered outputs such as accuracy, detectability, positivity and change of management. Using AMSTAR-2, the meta-analysis methods and results were evaluated with 16 questions able to identify critical weaknesses, such as risk of bias, publication bias, true effect, and study heterogeneity. To increase the observational number of patients, to register positive and negative findings, and consolidate regional and multi-center clinical data which were suggestions on study design, structure and statistics made to improve the quality in future primary and secondary studies.

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  • IPEN-DOC 25858

    PETRI, A.R. ; MANGIAROTTI, A.; GONCALVES, J.A.C. ; BUENO, C.C. . Effect of the ohmic drop in a RPC-like chamber for measurements of electron transport parameters. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-11, 2019. DOI: 10.15392/bjrs.v7i2A.637

    Abstract: The main advantage of Resistive Plate Chambers (RPCs), applied, for instance, in High-Energy Experiments and Positron Emission Tomography (PET), is that it is spark-protected due to the presence of, at least, one high-resistive electrode. However, the ohmic drop across the latter can affect the charge multiplication significantly. In this work, we investigate this effect in a RPC-like chamber. The counter was filled with nitrogen at atmospheric pressure and the primary ionization was produced by the incidence of nitrogen pulsed laser beam on an aluminum cathode. The illumination area of the cathode was measured using a foil of millimetric paper overlaid on this electrode. In this way, the resistance of the glass anode could be estimated using the known resistivity of the glass (ρ=2×1012 Ω.cm). Therefore, the voltage drop across the dielectric was calculated by the product of the current across the gas gap and the anode resistance. In order to mitigate the effect of the resistive electrode, the laser beam intensity was limited by interposing metallic meshes between the laser and the chamber window. The dependence of the ohmic drop from the applied voltage was analyzed. The results obtained shown that, without the meshes, the ohmic drop corresponds up to 7% of the applied voltage, preventing the detection system to reach values of density-normalized electric fields in the gas gap (Eeff/N) higher than 166 Td. By minimizing the laser beam intensity and, consequently, the primary ionization, the ohmic drop represented only 0.2% of the applied voltage, extending the Eeff /N range up to 175 Td.

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  • IPEN-DOC 25857

    OLIVEIRA-SILVA, TAMIRES de; ALVARENGA, LETICIA H.; LIMA-LEAL, CINTIA; GODOY-MIRANDA, BIANCA; CARRIBEIRO, PAMELA; SUZUKI, LUIS C. ; RIBEIRO, MARTHA S. ; KATO, ILKA T.; PAVANI, CHRISTIANE; PRATES, RENATO A.. Effect of photodynamic antimicrobial chemotherapy on Candida albicans in the presence of glucose. Photodiagnosis and Photodynamic Therapy, v. 27, p. 54-58, 2019. DOI: 10.1016/j.pdpdt.2019.05.032

    Abstract: Background: Candida albicans is an opportunistic commensal microorganism, often associated with severe infections in immunosuppressed individuals. C. albicans has hexose transporters that may favor the intracellular accumulation of photosensitizer (PS). the aims of this study were to investigate the influence of glucose load on photodynamic antimicrobial chemotherapy (PACT); and the role that membrane transport system plays on this therapy in the presence of glucose. Material and methods: Strains of C. albicans were selected: ATCC 10231, YEM 12, YEM 13, YEM 14 and YEM 15. All strains were grown aerobically on Sabouraud agar and incubated at 30 °C for 24 h. The strains were treated with and without glucose, and divided into Control (no treatment), LED light (660 nm, 166 mW/cm2), Photosensitizer (100 μM methylene blue) and PACT at 1, 3 and 6 min of irradiation groups. The colony forming units were counted and data submitted to statistical analysis (ANOVA) and Tukey's test. The concentration of methylene blue (MB) outside the yeast was measured by fluorescence spectroscopy. Results: PACT inactivate C. albicans and the presence of glucose did not affect the killing effect for most strains. Only YEM12 was partially affected by its presence. Regarding efflux systems, ABC overexpressing strain showed a protective effect on the yeast cells. We observed that yeast with overexpression of major facilitator superfamily (MFS) membrane pore tended to accumulate more MB in its cytoplasm, whereas strains that overexpressed ABC pumps (ATP-binding cassette transporters) tended to decrease MB uptake and survive the photodynamic challenge. Conclusion: Presence of glucose showed a small effect on PACT . The accumulation of MB on yeast induces more photodynamic inactivation; however, the photodynamic efficacy depends on the type and characteristics of the microbial strain.

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  • IPEN-DOC 25856

    JUNOT, DANILO O. ; SANTOS, ANA G.M.; ANTONIO, PATRICIA L. ; REZENDE, MARCOS V.S.; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . Dosimetric and optical properties of CaSO4:Tm and CaSO4:Tm,Ag crystals produced by a slow evaporation route. Journal of Luminescence, v. 210, p. 58-65, 2019. DOI: 10.1016/j.jlumin.2019.02.005

    Abstract: The motivation of this work was to produce TL dosimeters based on crystals of CaSO4 doped with thulium and silver, by means of a suitable new route. The crystals were produced by an adaptation of the slow evaporation route using calcium carbonate (CaCO3) as precursor, and incorporating the dopants (Tm2O3 and silver nanoparticles) in a solution of sulfuric acid, which is evaporated resulting in CaSO4:Tm or CaSO4:Tm,Ag crystal powders. X-ray diffraction analyses showed that the produced samples exhibit only a single phase corresponding to the crystal structure of anhydrite. Optical characterization was performed to determine the band gap of the materials. Samples did not show a reasonable OSL signal after stimulation with blue LEDs. TL characteristics such as glow curves, linearity and reproducibility of response, minimum detectable dose and fading were evaluated. The CaSO4:Tm samples showed TL emission glow curves with peaks in temperatures proper for dosimetry. The CaSO4:Tm,Ag samples presented a very intense peak displaced to high temperatures that could only be observed by applying heating rates below 4 °C/s. Samples doped with thulium oxide and silver nanoparticles showed the highest TL intensity and lowest fading.

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  • IPEN-DOC 25855

    AGUIAR, D.J.M. de; PADILHA, A.F.; PLAUT, R.L.; SILVA, M.R. da; LIMA, N.B. de . Comparative study on the forming and reversion of strain-induced martensite in two duplex stainless steels: developing a model for VSM. Journal of Magnetism and Magnetic Materials, v. 485, p. 8-15, 2019. DOI: 10.1016/j.jmmm.2019.04.054

    Abstract: An original feature of this work is the proposal of two equations to fit the volume fraction of ferromagnetic (α+α′) phases that can be applied in the measurement of magnetic saturation of comminuted duplex and superduplex stainless steels (for example, powders or filed chips). Duplex stainless steels contain similar volume fractions of austenite (γ) and ferrite (α) in their microstructure. Two steels exemplify this class, namely the most widely used duplex UNS S31803 and superduplex UNS S32520 stainless steels. The phenomena of work hardening, formation, and reversion of strain-induced martensite (α′) in austenite were compared in both stainless steels. Samples were work-hardened and annealed under identical conditions, and their behavior was evaluated mainly through X-ray diffraction and magnetic measurements. Notably, the volume fraction of strain-induced α′ in duplex stainless steel was as high as 32%, which indicated that this steel had a greater tendency to form α′ than superduplex stainless steel, for which the corresponding value equaled 15%. Annealing at 650 °C for 2 h promoted the reversion of strain-induced α′ into γ, decreasing the volume fraction of the former phase from 32 to 2% (duplex) and from 15 to 6% (superduplex).

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  • IPEN-DOC 25854

    GABBAI-ARMELIN, P.R.; FERNANDES, K.R.; MAGRI, A.M.P.; SILVA, A.C. da; FORTULAN, C.A.; RENNO, A.C.M.. Characterization and cytotoxicity evaluation of bio-inspired bioactive Glass/Collagen/Magnesium composites. Materials Chemistry and Physics, v. 228, p. 201-209, 2019. DOI: 10.1016/j.matchemphys.2019.02.072

    Abstract: Bone fractures are a common clinical event related to trauma, aging or diseases. Since bone repair is complex, abnormal consolidation may occur or, even, non-union. Biomaterials have a key role in this context, since they can stimulate bone cell differentiation, accelerating the healing process. Bioactive glasses (BG) represent a promising class of biomaterials due to its high bioactivity and osteogenic potential. Nevertheless, the osteoconductive properties of BG may not be enough to stimulate consolidation in critical situations. Thus, it was hypothesized that enriching BG with other materials such as collagen (Col) and magnesium (Mg), trying to make a composite with similar properties to bone tissue, would constitute a more suitable graft for tissue engineering. This work aimed at obtaining BG/Col/Mg composites and evaluating their physicochemical features. Moreover, L929 and MC3T3-E1 cell culture studies were done to investigate the cytotoxicity of the composites. The results showed that Mg could be successfully introduced, at different percentages (1, 3 and 5%), into BG and BG/Col composites, improving mechanical properties and retaining the bioactivity of BG. Ca assay measurements demonstrated that reactions in the Mg/solution interface, i.e. reactions between Mg and the ions in the simulated body fluid (SBF) have led to an increased Ca uptake for compositescontaining 3 and 5% Mg compared to plain BG and BG/Col. In vitro studies showed that BG and BG/Col containing 1% of Mg were non-cytotoxic and biocompatible. This percentage of Mg is promising for forward works. Our data on the present BG/Mg and BG/Col/Mg-based composites are encouraging and may lead to further molecular and cell culture studies, and in vivo investigations to clarify the biological performance of these new biomaterials.

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  • IPEN-DOC 25853

    PINHEIRO, ANDRE L.G.; CARMO, JOSE V.C. do; CARVALHO, DAVI C.; OLIVEIRA, ALCINEIA C.; RODRIGUEZ-CASTELLON, ENRIQUE; TEHUACANERO-CUAPA, SAMUEL; OTUBO, LARISSA ; LANG, ROSSANO. Bio-additive fuels from glycerol acetalization over metals-containing vanadium oxide nanotubes (MeVOx-NT in which, Me=Ni, Co, or Pt). Fuel Processing Technology, v. 184, p. 45-56, 2019. DOI: 10.1016/j.fuproc.2018.11.008

    Abstract: The biodiesel production has led to a drastic surplus of glycerol and catalytic conversion of glycerol into valueadded products is of great industrial importance. Thus, the acetalization of glycerol with ketone or aldehydes allows the glycerol transformation into bio–additive fuels. In this work, metals-containing vanadium oxides nanotubes (MeVOx NT in which, Me=Co, Pt or Ni) have been synthesized with additional internal porosity and tested in the acetalization of glycerol with acetone (AG) for valuable biofuels production. The catalysts showed remarkable performances in the AG reaction. Furthermore, by variation of the composition, catalyst loading and temperature and using distinct substrates (butyraldehyde, furfuraldehyde and benzaldehyde), NiVOxNT is active, being very selective to solketal and reciclable for 4 times in the AG reaction. On the contrary, pure VOx NT easily deactivated due to the structure agent removal during the reaction, which promote the collapse of the tubular structure. The CoVOxNT and PtVOxNT catalysts did not exhibit such a stable structure and easily deactivated in the reaction due to leaching of the metals oxides during the AG.

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  • IPEN-DOC 25851

    BENEDETTO, RAQUEL ; MASSICANO, ADRIANA V.F.; CRENSHAW, BRYANT K.; OLIVEIRA, RENATO; REIS, RUI M.; ARAUJO, ELAINE B. ; LAPI, SUZANNE E.. Zr-89-DFO-cetuximab as a molecular imaging agent to identify cetuximab resistance in head and neck squamous cell carcinoma. Cancer Biotherapy and Radiopharmaceuticals, v. 34, n. 5, p. 288-296, 2019. DOI: 10.1089/cbr.2018.2616

    Abstract: Background: Despite the improvement in clinical outcomes for head and neck squamous cell carcinoma (HNSCC) as the result of cetuximab, patients may present with or develop resistance that increases tumor recurrence rates and limits clinical efficacy. Therefore, identifying those patients who are or become resistant is essential to tailor the best therapeutic approach. Materials and Methods: Cetuximab was conjugated to p-NCS-Bz-DFO and labeled with 89Zr. The resistance model was developed by treating FaDu cells with cetuximab. Western blotting (WB) and specific binding assays were performed to evaluate epidermal growth factor receptor (EGFR) expression and 89Zr-DFO-cetuximab uptake in FaDu cetuximab-resistant (FCR) and FaDu cetuximab-sensitive (FCS) cells. Positron emission tomography imaging and biodistribution were conducted in NU/NU nude mice implanted with FCR or FCS cells. Results: Cetuximab was successfully radiolabeled with 89Zr (‡95%). Binding assays performed in FCR and FCS cells showed significantly lower 89Zr-DFO-cetuximab uptake in FCR ( p < 0.0001). WB suggests that the resistance mechanism is associated with EGFR downregulation ( p = 0.038). This result is in agreement with the low uptake of 89Zr-DFO-cetuximab in FCR cells. Tumor uptake of 89Zr-DFO-cetuximab in FCR was significantly lower than FCS tumors ( p = 0.0340). Conclusions: In this work, the authors showed that 89Zr-DFO-cetuximab is suitable for identification of EGFR downregulation in vitro and in vivo. This radiopharmaceutical may be useful for monitoring resistance in HNSCC patients during cetuximab therapy.

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  • IPEN-DOC 25850

    FRIMAIO, AUDREW ; NASCIMENTO, BRUNA C.; BARRIO, RAMON M.M.; CAMPOS, LETICIA L. ; COSTA, PAULO R.. X-ray spectrometry applied for determination of linear attenuation coefficient of tissue-equivalent materials. Radiation Physics and Chemistry, v. 160, p. 89-95, 2019. DOI: 10.1016/j.radphyschem.2019.03.021

    Abstract: Resin-based materials equivalent to water were developed and four different samples were obtained. The linear attenuation coefficients of all samples was evaluated using X-ray spectrometry with primary and transmitted beams using voltages at the ranging from 60 to 120 kV. The experimental measured values were compared with theoretical reference values to water and with that obtained using the Least Square Method algorithm methodology (method applied to diagnostic radiology and radiotherapy). Our results show that differences between the measured values and the target μ(E) was lower than 7% ± 0.3 in the energy range from 20 to 80 keV. These results enable to consider that the material developed and produced is a good option to be used as a waterequivalent material and the experimental method adequate to its quantitative evaluation.

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  • IPEN-DOC 25849

    BARROSO, A.G.; GARCIA, R.H.L. ; DEL MASTRO, N.L. . X-ray diffraction pattern and relative crystallinity of irradiated arrowroot starch. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-7, 2019. DOI: 10.15392/bjrs.v7i2A.645

    Abstract: After cereals, tubers and roots are the major source of starch for food and industrial uses. Arrowroot refers to any plant of the genus Marantha, but the term is most commonly used to describe the easily digested starch ob-tained from the rhizomes of Marantha arundinacae. The rhizomes of this herbaceous plant contain about 20% of starch. As few studies exist on arrowroot starch, the objective of this preliminary work was to study the X-ray diffraction (XRD) patterns of arrowroot starch when treated by γ-radiation with doses up to 15 kGy in a 60Co source. The XRD patterns of the arrowroot starch exhibited A-type crystalline arrangements with strong peaks at approximately 15º, 17º, 18º and 23º (2θ). A slight increase of diffractogram peaks intensity was noticed after the irradiation process. The cristallinity index was calculated using Bruker DIFFRAC.EVA version 4.2 software. Relative crystallinity seems to increase with irradiation at low doses that could be attributed to different radia-tion sensitivity among the amorphous and crystalline regions of the arrowroot starch molecule. Present results will contribute to elucidate the behavior under radiation treatment of this starchy component increasingly em-ployed by the food industry.

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  • IPEN-DOC 25848

    ICHIKAWA, R.U. ; LINHARES, H.M.S.M.D.; SILVA, A.S.B. da ; TEIXEIRA, M.I. ; RANIERI, I.M. ; TURRILLAS, X.; MARTINEZ, L.G. . X-ray diffraction analysis of KY3F10 nanoparticles doped with Nd and preliminary studies for its use in high-dose radiation dosimetry. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i2A.586

    Abstract: In this work, the structure and microstructure of Nd:KY3F10 nanoparticles was probed using X-ray synchrotron diffraction analysis. Rietveld refinement was applied to obtain cell parameters, atomic positions and atomic dis-placement factors to be compared with the ones found in literature. X-ray line profile methods were applied to determine mean crystallite size and crystallite size distribution. Thermoluminescent (TL) emission curves were measured for different radiation doses, from 0.10 kGy up to 10.0 kGy. Dose-response curves were obtained by area integration beneath the peaks from TL. The reproducibility of the results in this work has shown that this material can be considered a good dosimetric material.

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  • IPEN-DOC 25847

    ANDRADE, ADRIANO B.; BISPO, GIORDANO F. da C.; MACEDO, ZELIA S.; BALDOCHI, SONIA L. ; YUKIHARA, EDUARDO G.; VALERIO, MARIO E.G.. VUV excited luminescence and thermoluminescence investigation on Er3+- or Pr3+-doped BaY2F8 single crystals. Optical Materials, v. 90, p. 238-243, 2019. DOI: 10.1016/j.optmat.2019.02.044

    Abstract: Photoluminescence (PL), thermoluminescence (TL) emission spectra and TL glow curves of barium yttrium fluoride (BaY2F8 – BaYF), undoped and doped with erbium (Er3+) or praseodymium (Pr3+) were measured to investigate the fundamental absorption (band gap – Eg), the nature of the trapping centers, as well as the electronic transitions of Ln3+ in BaYF host. The band gap energy Eg of BaY2F8 was determined by vacuum ultraviolet (VUV) excitation measurements to be around 11.2 eV. Additionally, the electronic transition from excited states of Ln3+ ions and the exciton state were also identified. TL emission spectra showed that the TL emission of doped samples is related to the Ln3+ ion, indicating that the related host trapping centers are not affected by the new trapping centers originated due the dopant ions. Trap depths were calculated by fitting the glow curves using a first order kinetics model. Host-related trapping centers were attributed to intrinsic defects such as Vk and F centers and the new TL peaks observed for Ere and Pr-doped samples was associated to the electrons trapping centers. These results lead us to propose a simple model to explain the origin of the TL emission in BaYF.

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  • IPEN-DOC 25846

    SOUZA, C.H. ; SHORTO, J.M.B. ; SIQUEIRA, P.T.D. ; NUNES, M.G. ; SILVA JUNIOR, I.A. ; YORIYAZ, H. . Verification of angular dependence in MOSFET detector. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-11, 2019. DOI: 10.15392/bjrs.v7i2A.734

    Abstract: In vivo dosimetry is an essential tool for quality assurance programs, being a procedure commonly performed with thermoluminescent dosimeters (TLDs) or diodes. However, a type of dosimeter that has increasing popularity in recent years is the metal-oxide-semiconductor field effect transistor (MOSFET) detector. MOSFET dosimeters fulfill all the necessary characteristics to realize in vivo dosimetry since it has a small size, good precision and feasibility of meas-urement, as well as easy handling. Nevertheless, its true differential is to allow reading of dose in real time, enabling immediate intervention in the correction of physical parameters deviations and anticipation of small anatomical changes in the patient during treatment. In order for MOSFET dosimeter to be better accepted in clinical routine, information reporting performance should be available frequently. For this reason, this work proposes to verify reproducibility and angular dependence of a standard sensitivity MOSFET dosimeter (TN-502RD-H) for Cs-137 and Co-60 sources. Exper-imental data were satisfactory and MOSFET dosimeter presented a reproducibility of 3.3% and 2.7% (±1 SD) for Cs-137 and Co-60 sources, respectively. In addition, an angular dependence of up to 6.1% and 16.3% for both radioactive sources, respectively. It is conclusive that MOSFET dosimeter TN-502RD-H has satisfactory reproducibility and a considerable angular dependence, mainly for the Co-60 source. This means that although precise measurements, special attention must be taken for applications in certain anatomical regions in a patient.

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  • IPEN-DOC 25845

    CARVALHO, P.R. ; MUNITA, C.S. ; LAPOLLI, A.L. . Validity studies among hierarchical methods of cluster analysis using cophenetic correlation coefficient. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.668

    Abstract: The literature presents many methods to produce data set clusters and the better method choice becomes hardest because the various combinations between them based on different dissimilarity measures can lead to different cluster patterns and false interpretations. Nevertheless, little effort has been expended in evaluating these methods empirically using an archeological data set. In this way, this work has the objective to develop a comparative study of the cluster analysis methods and to identify what is the most appropriate for an archeological data set. For this, 45 ceramic fragments samples data set was analyzed by instrumental neutron activation analysis (INAA). And, five hierarchical methods of cluster were used to this data set: Single linkage, Complete linkage, Average linkage, Centroid and Ward. The validation was done calculating cophenetic correlation coefficient values by a statistical program R and the comparison between them showed the average linkage method was more accurate for the 45 ceramic fragments samples data set. With this, the statistical program R showed be an tool option for other scientists to calculate their cophenetic correlation coefficient and to identify the more accurate methods for their archeological data set.

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  • IPEN-DOC 25844

    DEL NERO, R.A. ; NAKANDAKARI, M.V.N.; YORIYAZ, H. . Validating a virtual source model based in Monte Carlo method for profiles and percent depth doses calculation. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-8, 2019. DOI: 10.15392/bjrs.v7i2A.689

    Abstract: The Monte Carlo method for radiation transport has been adapted for medical physics application. More specifically, it has received more attention in clinical treatment planning with the development of more efficient computer simulation techniques. In linear accelerator modeling by the Monte Carlo method, the phase space data file (phsp) is an alternative representation for radiation source. However, to create a phase space file and obtain good precision in the results, it is necessary detailed information about the accelerator's head and commonly the supplier does not provide all the necessary data. An alternative to the phsp is the Virtual Source Model (VSM). This alternative approach presents many advantages for the clinical Monte Carlo application. This is the most efficient method for particle generation and can provide an accuracy similar when the phsp is used. This research propose a VSM simulation with the use of a Virtual Flattening Filter (VFF) for profiles and percent depth doses calculation. Two different sizes of open fields (40 x 40 cm² and 40 x 40 cm² rotated 45°) were used and two different source to surface distance (SSD) were applied: the standard 100 cm and custom SSD of 370 cm, which is applied in radiotherapy treatments of total body irradiation. The data generated by the simulation was analyzed and compared with experimental data to validate the VSM. This current model is easy to build and test.

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  • IPEN-DOC 25843

    YAMAGATA, C. ; LEME, D.R. ; CASTANHO, S.R.H.M. . Use of waste water glass as silica supplier in synthesis of pure and Mg-doped lanthanum silicate powders for IT-SOFC application. Journal of the European Ceramic Society, v. 39, n. 12, p. 3416-3420, 2019. DOI: 10.1016/j.jeurceramsoc.2019.03.045

    Abstract: Water glass in alkali solution (Na2SiO3/NaOH) an abundant effluent, generated in the alkaline fusion of zircon sand, represents a potential silica source to be converted in useful silica technological application. Actually, the generation of energy by environmental-friendly method is one of the major challenges for researchers. Solid Oxide Fuel Cells (SOFC) is efficient and environmentally clean technique to energy production, since it converts chemical energy into electrical power, directly. Apatite-type lanthanum silicates are promising materials for application as an electrolyte in intermediate temperature SOFC (IT-SOFC) because of their higher ionic conductivity, in temperatures of range 600–700 °C, than conventional zirconia electrolytes. In this work, pure (La9,56(SiO4)6O2,34) and Mg-doped (La9,8Si5,7Mg0,3O26,4) lanthanum silicate were synthesized, from that rich effluent. Using the sol-gel followed by precipitation method, the single crystalline apatite phase of both silicates was obtained by thermal treatment at 900 °C of their precursors. Sintered ceramic samples reached density of higher than 90%.

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  • IPEN-DOC 25842

    CARVALHO, LUMA R. de ; BONFIM, LETICIA ; VIEIRA, DANIEL P. . Use of 2-color flow cytometry to assess radiation-induced genotoxic damage on CHO-KI cells. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i2A.570

    Abstract: The micronucleus assay is an important technique used to evaluate genotoxic damage of chemical or physical agents (as ionizing radiations) on cells, based on quantification of cells bearing micronuclei, which are fragments derived from damage (breakage) of the DNA. Currently, this technique was updated to an automated approach that relies on plasma membrane dissolution to analyze fluorescent dye-labelled nuclei and micronuclei by flow cytometry. Cell suspensions were irradiated in PBS by a 60Co source in doses between 0 and 16 Gy, and incubat-ed by 72h. Cell membranes were lysed in the presence of SYTOX Green and EMA dyes, so EMA-stained nuclei could be discriminated as from dead cells, and nuclei and micronuclei could be quantified. Amounts of micronu-clei (percent of events) in the samples, were found to be proportional to radiation doses, and could be fitted to a linear-quadratic model (R² = 0.993). Only higher doses (8 and 16 Gy) and positive control could induce relevant increases in micronucleus amounts. The incorporation EMA showed an increase in irradiated cells. Mid- to high doses (4, 8 and 16 Gy) induced reduction of cell proliferation. Experiments showed the suitability of the tech-nique to replace traditional microscopy analysis in evaluation of the effects of ionizing radiations on cells, with possibility to use in biological dosimetry.

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  • IPEN-DOC 25841

    VIEIRA, LUDMILA C. ; ARAUJO, LEANDRO G. de; FERREIRA, RAFAEL V. de P.; SILVA, EDSON A. da; CANEVESI, RAFAEL L.S.; MARUMO, JULIO T. . Uranium biosorption by Lemna sp. and Pistia stratiotes. Journal of Environmental Radioactivity, v. 203, p. 179-186, 2019. DOI: 10.1016/j.jenvrad.2019.03.019

    Abstract: Biosorption-based technologies have been proposed for the removal of radionuclides from radioactive liquid waste containing organic compounds. Nevertheless, pytoremediation potential of uranium (U) by nonliving aquatic macrophytes Lemna sp. and Pistia stratiotes has not been previously addressed. In this study, uranium biosorption capacity by Pistia stratiotes and Lemna sp. was evaluated by equilibrium and kinetics experiments. The biomasses were added to synthetic and real waste solutions. The assays were tested in polypropylene vials containing 10 mL of uranium nitrate solution and 0.20 g of biomass. Solutions ranging from 0.25 to 84.03 mmol l−1 were employed for the assessment of uranium concentration in each macrophyte. The equilibrium time was 1 h for both macrophytes. Lemna sp. achieved the highest sorption capacity with the use of the synthetic solution, which was 0.68 mmol g−1 for the macrophyte. Since Lemna sp. exhibit a much higher adsorption capacity, only this biomass was exposed to the actual waste solution, being able to adsorb 9.24×10−3 mmol g−1 U (total). The results show that these materials are potentially applicable to the treatment of liquid radioactive waste.

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  • IPEN-DOC 25840

    APPANNABABU, S.; LICHTENTHALER, R.; ALVAREZ, M.A.G.; RODRIGUEZ-GALLARDO, M.; LEPINE-SZILY, A.; PIRES, K.C.C.; SANTOS, O.C.B.; SILVA, U.U.; FARIA, P.N. de; GUIMARÃES, V.; ZEVALLOS, E.O.N.; SCARDUELLI, V.; ASSUNÇÃO, M.; SHORTO, J.M.B. ; BARIONI, A.; ALCANTARA-NUNEZ, J.; MORCELLE, V.. Two-neutron transfer in the He-6 + Sn-120 reaction. Physical Review C, v. 99, n. 1, p. 014601-1 - 014601-7, 2019. DOI: 10.1103/PhysRevC.99.014601

    Abstract: A large yield of α particles produced in the 120Sn(6He, α) reaction was measured at 20.3-, 22.2-, 22.4-, and 24.5-MeV bombarding energies. The α particles are distributed over a broad energy range in the vicinity and below the elastic scattering 6He peak. Energy integrated α-particle cross sections have been obtained at θlab = 36◦, 40◦, and 60◦. The α energy distributions have been analyzed at a fixed laboratory angle (≈60◦) in terms of the reaction Q value, considering the 2n-transfer reaction kinematics 120Sn(6He, α)122Sn. A kinematical analysis of the Q-value distribution shows that the recoil system 120Sn + 2n is formed in highly excited states in the continuum, at increasing excitation energies as the bombarding energy increases. It is shown that by using Brink’s formula, the excitation energy depends on the transferred angular momentum following a linear relation with the square of the angular momentum, indicating that some kind of dinuclear rotating system is formed after the reaction.

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  • IPEN-DOC 25839

    ESPOSITO, VINCENZO; KABIR, AHSANUL; ROSA, MASSIMO; NONG, NGO V.; RODRIGUES, THENNER S. ; RODRIGUES, LAYS N. ; MACHADO, MARINA F.S. ; MORAES, LETICIA P.R. ; MARANI, DEBORA; FONSECA, FABIO C. . Tuning diffusion paths in shaped ceria nanocrystals. CrystEngComm, v. 21, n. 27, p. 4025-4029, 2019. DOI: 10.1039/c9ce00414a

    Abstract: Mass diffusion controls material structuring from the atomic to the macro-scale defining properties and functionalities. We show here that surface energy in Ce0.9Gd0.1O3-d shaped nanocrystals, i.e. nanocubes, nanorods and spherical nanoparticles, can control solid state diffusion mechanisms over a long range, leading to extreme microstructural diversity.

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  • IPEN-DOC 25838

    COURROL, DANIELLA dos S.; LOPES, CARLA R.B.; PEREIRA, CAMILA B.P.; FRANZOLIN, MARCIA R.; SILVA, FLAVIA R. de O. ; COURROL, LILIA C.. Tryptophan silver nanoparticles synthesized by photoreduction method: characterization and determination of bactericidal and anti-biofilm activities on resistant and susceptible bacteria. International Journal of Tryptophan Research, v. 12, p. 1-8, 2019. DOI: 10.1177/1178646919831677

    Abstract: The high rates of antibiotics use in hospitals have resulted in a condition where multidrug-resistant pathogens have become a severe threat to the human health worldwide. Therefore, there is an increasing necessity to identify new antimicrobial agents that can inhibit the multidrugresistant bacteria and biofilm formation. In this study, antibacterial and anti-biofilm activities of tryptophan silver nanoparticles (TrpAgNP) were investigated. The TrpAgNPs were synthesized by photoreduction method, and the influence of irradiation time and concentration of reagents were analyzed. The nanoparticles were characterized by transmission electron microscopy, Zeta Potential and (UV)-absorption spectra. The antibacterial activity of TrpAgNPs was tested for antibiotic-resistant and susceptible pathogens, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Salmonella typhimurium, and Pseudomonas aeruginosa, evaluating the influence of photoreduction parameters in bactericidal effect. The results have shown that TrpAgNPs solutions with lower tryptophan/silver nitrate (AgNO3) ratio and higher AgNO3 concentration have higher bactericidal action against bacteria with inhibition of ~100% in almost all studied bacterial strains. The antimicrobial activity of TrpAgNPs within biofilms generated under static conditions of antibiotic-resistant and susceptible strains of S. aureus, S. epidermidis, E. coli, K. pneumoniae, C. freundii, and P. aeruginosa was also investigated. The results showed that TrpAgNPs have an inhibitory effect against biofilm formation, exceeding 50% in the case of Gram-negative bacteria (E. coli, K. pneumoniae, C. freundii, and P. aeruginosa—54.8% to 98.8%). For Gram-positive species, an inhibition of biofilm formation of 68.7% to 72.2 % was observed for S. aureus and 20.0% to 40.2% for S. epidermidis.

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  • IPEN-DOC 25837

    ROSA, JORGE M. ; GARCIA, VANESSA S.G. ; BOIANI, NATHALIA F. ; MELO, CAMILA G.; PEREIRA, MARIA C.C. ; BORRELY, SUELI I. . Toxicity and environmental impacts approached in the dyeing of polyamide, polyester and cotton knits. Journal of Environmental Chemical Engineering, v. 7, n. 2, p. 1-7, 2019. DOI: 10.1016/j.jece.2019.102973

    Abstract: Three colouration process was analyzed, in which consumption of water, the spent of electrical and thermal energy, emission of carbon dioxide besides effluent toxicity of dyeing of polyamide, cotton and polyester knits were approached. the dyeing of polyamide knit presented lowest consumption of electrical energy, the dyeing of polyester knit presented the lowest consumption of thermal energy and emission of co2 molecules into atmosphere, and the effluent of cotton dyeing presented lowest acute toxicity (CE50) to Daphnia similis.

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  • IPEN-DOC 25836

    CANO, NILO F.; RAO, T.K.G.; AYALA-ARENAS, JORGE S.; GONZALES-LORENZO, CARLOS D.; OLIVEIRA, LETICIA M. ; WATANABE, SHIGUEO. TL in green tourmaline: study of the centers responsible for the TL emission by EPR analysis. Journal of Luminescence, v. 205, p. 324-328, 2019. DOI: 10.1016/j.jlumin.2018.09.034

    Abstract: Electron paramagnetic resonance (EPR) studies have been carried out to identify the defect centers responsible for the thermoluminescence (TL) peaks in the mineral tourmaline. The mineral exhibits three TL peaks approximately at 170, 250 and 310 °C. The EPR spectrum of the green tourmaline sample pre-heated to 500 °C presented a large signal around g=4.3 due to Fe3+ ion. Room temperature EPR spectrum of irradiated green tourmaline shows the formation of two defect centers in the region of g=2.0. One of the centers (center II) with a g factor equal to 1.96 is identified as an F+-center and is related to the observed high temperature 250 and 310 °C TL peaks. Center I exhibiting a doublet is due to hydrogen atoms (H0), stable in the crystal lattice at room temperature and this center correlates with the TL peak at 170 °C of the green tourmaline. An optical absorption measurement also was carried out. Bands at around 430, 730 and 1100 nm have been observed.

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  • IPEN-DOC 25835

    MURATA, CAMILA H.; HONDA, CRISTIANE J.C. ; LAVINIA, NICOLAS C.; CALDAS, LINDA V.E. ; MEDEIROS, REGINA B.. The performance of a prototype device designed to evaluate quality parameters of radiological equipment: complementary study. Radiation Physics and Chemistry, v. 159, p. 131-137, 2019. DOI: 10.1016/j.radphyschem.2019.02.034

    Abstract: Quality control measurements in radiological equipment are essential to verify their achievable performance standards, as average peak voltage (kVp), practical peak voltage (kVpp), exposure time, radiation dose and halfvalue layer (HVL). In a recent study, a multifunctional prototype's partial results were presented using a solidstate detector to evaluate quality parameters as kVp, exposure time and HVL of radiological equipment. In the present work, the accuracy of these measurements was improved, and dosimetric parameters were developed aiming to comply with normative requirements. The prototype board hardware was built with four sensors PIN RD100 A and a dedicated software based on their signals. In a single exposure, these signals were used in settled polynomial functions to determine kVp, kVpp, exposure time, radiation dose, dose rate and HVL. Characterization tests were undertaken at an instruments calibration laboratory and at a clinical research laboratory. A mathematical function was fitted for 50–120 kVp range, with R2 =0.999. This new algorithm allowed improving the kVp accuracy from [0.3–2.3%] to [0.03–1.5%]. The reproducibility and accuracy of the radiation dose rate reached 0.94% and 0.34%, respectively. The dose range measurements varied from 0.01 to 40 mGy. In addition, calibration tests were performed in calibration laboratory at standard traceable radiation qualities of RQR6 and RQR8. The total uncertainty associated with this calibration did not exceed 2%. In conclusion, the prototype can be considered a multifunctional non-invasive instrument appropriate to evaluate radiological equipment performance with an effective range from 50 kV to 120 kV.

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  • IPEN-DOC 25834

    DONATUS, UYIME ; KLUMPP, RAFAEL E. ; MOGILI, NAGA V.V.; ANTUNES, RENATO A.; MILAGRE, MARIANA X. ; COSTA, ISOLDA . The effect of surface pretreatment on the corrosion behaviour of silanated AA2198‐T851 Al‐Cu‐Li alloy. Surface and Interface Analysis, v. 51, n. 2, p. 275-289, 2019. DOI: 10.1002/sia.6584

    Abstract: The corrosion behaviour of silanated AA2198‐T851 alloy substrates with and with no manufacturing‐process induced near‐surface deformed layer (MPI‐NSDL) has been investigated. Two methods (alkaline etching + desmutting and mechanical polishing) were employed in removing the MPI‐NSDL. Silanization was performed using 2‐bistriethoxysilylethane. Electrochemical impedance spectroscopy (EIS), salt spray test, and microscopy techniques were employed in the investigation of the corrosion behaviours. The studies revealed that polishing appeared to be the best silanating pre‐treatment (compared with degreasing and etching + desmutting) for the new generation AA2198‐T851 Al‐Cu‐Li alloy, and this was reflected in the EIS spectra. The etched + desmutted and the degreased surface with MPI‐NSDL did not respond well to silanization and presented more pitting sites per square millimeter. However, the severity of corrosion per pit was more on the polished sample compared with the other two. Also, the corrosion mechanisms were different for the three cases.

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  • IPEN-DOC 25833

    CASTRO, MICHELE C.B. de ; COUTO, ANTONIO A. ; ALMEIDA, GISELE F.C. ; MASSI, MARCOS; LIMA, NELSON B. de ; SILVA SOBRINHO, ARGEMIRO da; CASTAGNET, MARIANO ; XAVIER, GLEICY L. ; OLIVEIRA, RENE R. . The effect of plasma nitriding on the fatigue behavior of the Ti-6Al-4V alloy. Materials, v. 12, n. 3, p. 1-13, 2019. DOI: 10.3390/ma12030520

    Abstract: The Ti-6Al-4V alloy is widely used in the manufacture of components that must have low density and high corrosion resistance and fatigue strength. The fatigue strength can be improved by surface modification. The aim of this study was to determine the influence of plasma nitriding on the fatigue behavior of a Ti-6Al-4V alloy with a lamellar microstructure (Widmanstätten type). Nitriding was executed at 720 C for 4 h in an atmosphere with N2, Ar, and H2. Microstructure characterization of the samples was carried out by X-ray diffraction analysis, optical microscopy, and scanning electron microscopy. The average roughness of the specimens was determined, and fatigue tests were executed in a bending–rotating machine with reverse tension cycles (R = 􀀀1). X-ray diffraction analysis of the nitrided alloy revealed the following matrix phases: , , "-Ti2N, and -TiN. A nitrogen diffusion layer was formed between the substrate and the titanium nitrides. Plasma nitriding resulted in an increase in low-cycle fatigue strength, whereas at high cycles of 200 MPa, both conditions exhibited similar behaviors. The fracture surface of the fatigue-tested specimens clearly revealed the lamellar microstructure. The fracture mechanism in the non-nitrided specimens appears to be due to cracking at the interface of the and phases of the lamellar microstructure.

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  • IPEN-DOC 25832

    DONATUS, UYIME ; ARAUJO, JOAO V. de S. ; MACHADO, CARULINE de S.C. ; MOGILI, NAGA V.V.; ANTUNES, RENATO A.; COSTA, ISOLDA . The effect of manufacturing process induced near-surface deformed layer on the corrosion behaviour of AA2198-T851 Al–Cu–Li alloy. Corrosion Engineering, Science and Technology, v. 54, n. 3, p. 205-215, 2019. DOI: 10.1080/1478422X.2018.1558932

    Abstract: The effect of the near-surface deformed layer on the corrosion behaviour of AA2198-T851 Al–Cu–Li alloy has been investigated using microscopy and electrochemical techniques. This shows that a deformed layer developed by rolling was more active but only exhibited superficial attack compared to a mechanically polished surface, which produced severe localised corrosion associated with the presence of hexagonal T1 particles. The rolled surface became increasingly corrosion resistant with time, but when coupled, galvanically enhanced severe localised corrosion sites developed on the surface over time.

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  • IPEN-DOC 25831

    SILVA, JULIO C.M.; NTAIS, SPYRIDON; RAJARAMAN, VISHWANATHAN; TEIXEIRA-NETO, ERICO; TEIXEIRA-NETO, ANGELA A.; NETO, ALMIR O. ; ANTONIASSI, RODOLFO M. ; SPINACE, ESTEVAM V. ; BARANOVA, ELENA A.. The catalytic activity of Pt:Ru nanoparticles for ethylene glycol and ethanol electrooxidation in a direct alcohol fuel cell. Electrocatalysis, v. 10, n. 3, p. 203-213, 2019. DOI: 10.1007/s12678-019-00515-8

    Abstract: In this study, we investigated the carbon-supported PtRu nanoparticles with atomic ratios of Pt:Ru of 100:0, 90:10, 70:30, and 50:50 for ethanol and ethylene glycol electrooxidation in alkaline media. The nanoparticles were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon. The nanoparticle mean sizes were 7.3 nm, 5.7 nm, 5.2 nm, and 5.1 nm for Pt/C, Pt90Ru10/C, Pt70Ru30/C, and Pt50Ru50/C, respectively. X-ray diffraction (XRD) analysis revealed that Pt and PtRu electrocatalysts have face-centered cubic (fcc) structure and suggests the alloy formation for all PtRu/C materials, which was further supported by the X-ray photoelectron spectroscopy (XPS). Based on XPS analysis, Pt50Ru50/C has higher amount of Pt oxides on the surface than Pt70Ru30/C. Electrochemical results demonstrated that the addition of Ru to Pt enhances the catalytic activity towards ethanol and ethylene glycol electrooxidadion. The catalyst of Pt50Ru50/C composition showed the lowest onset potential for ethanol and ethylene glycol electrooxidation, which were 160 and 70 mV lower than for Pt/C, respectively. Furthermore, this catalyst outperformed Pt/C and other PtRu/C compositions in chronoamperometric and direct alcohol fuel cell (DAFC) experiments. DAFC experiments using Pt50Ru50/C as anode had the power density 40 and 14% higher than using Pt/C for ethanol and ethylene glycol, respectively. The promotion is due to the bi-functional mechanism and/or electronic effect of two metals in the alloy.

    Palavras-Chave: nanoparticles; electrocatalysts; oxidation; ethanol; ethylene glycols; electrochemical corrosion; fuel cells; direct ethanol fuel cells

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  • IPEN-DOC 25830

    SCIANI, JULIANA M.; NEVES, ADRIANA; VASSÃO, RUTH C.; SPENCER, PATRICK ; ANTONIAZZI, MARTA M.; JARED, CARLOS; PIMENTA, DANIEL C.. The amphibian diacylglycerol O-acyltransferase 2 (DGAT2): a ‘paleoprotein’ with conserved function but unique folding. Protein Journal, v. 38, n. 1, p. 83-94, 2019. DOI: 10.1007/s10930-019-09814-x

    Abstract: Amphibians are, currently, considered the first vertebrates that had performed the aquatic to terrestrial transition during evolution; therefore, water balance and dehydration control were prerequisites for such environment conquering. Among anurans, Phyllomedusa is a well-studied genus, due to its peptide-rich skin secretion. Here, we have analyzed the skin secretion of Phyllomedusa distincta targeting the proteins present in the skin secretion. The major soluble protein was chromatographically isolated and utilized to immunize rabbits. Through proteomics approaches, we were able to identify such protein as being the diacylglycerol O-acyltransferase 2 (DGAT2), a crucial enzyme involved in lipid synthesis and in the skin water balance. Immunohistochemistry assays revealed the protein tissular distribution for different animal species, belonging to different branches of the phylogenetic tree. Specifically, there was positivity to the anti-DGAT2 on Amphibians’ skin, and no antibody recognition on fish and mammals’ skins. The DGAT2 multiple sequence alignment reveals some degree of conservation throughout the genera; however, there is a different cysteine pattern among them. Molecular modeling analyses corroborate that the different cysteine pattern leads to distinct 3D structures, explaining the different antibody recognition. Moreover, the protein phylogenetic analyses place the Xenopus DGAT2 (the available amphibian representative) next to the Coelacanthus enzyme, which have led the authors to term this a ‘paleo-protein’. DGAT2 would be, therefore, an ancient protein, crucial to the terrestrial environment conquest, with a unique folding—as indicated by the molecular models and immunohistochemistry analyses—a consequence of the different cysteine pattern but with conserved biological function.

    Palavras-Chave: amphibians; peptides; skin; proteins; secretion; chemical analysis; temperature control

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  • IPEN-DOC 25829

    LOPES, FABIO J.S. ; SILVA, JONATAN J. ; MARRERO, JUAN C.A.; TAHA, GHASSAN; LANDULFO, EDUARDO . Synergetic aerosol layer observation after the 2015 Calbuco volcanic eruption event. Remote Sensing, v. 11, n. 2, p. 1-22, 2019. DOI: 10.3390/rs11020195

    Abstract: On 22 April 2015, the Calbuco volcano in Chile (Lat: 41.33 S, Long: 72.62 W) erupted after 43 years of inactivity followed by a great amount of aerosol injection into the atmosphere. The pyroclastic material dispersed into the atmosphere posed a potential threat to aviation traffic and air quality over affected a large area. The plumes and debris spread from its location to Patagonian and Pampean regions, reaching the Atlantic and Pacific Oceans and neighboring countries, such as Argentina, Brazil and Uruguay, driven by the westerly winds at these latitudes. The presence of volcanic aerosol layers could be identified promptly at the proximities of Calbuco and afterwards by remote sensing using satellites and lidars in the path of the dispersed aerosols. The Cloud-Aerosol Lidar and Pathfinder Satellite Observations (CALIPSO), Moderate Resolution Imaging Spectroradiometer (MODIS) on board of AQUA/TERRA satellites and Ozone Mapping and Profiler Suite (OMPS) on board of Suomi National Polar-orbiting Partnership (Suomi NPP) satellite were the space platforms used to track the injected layers and a multi-channel lidar system from Latin America Lidar Network (LALINET) SPU Lidar station in South America allowed us to get the spatial and temporal distribution of Calbuco ashes after its occurrence. The SPU lidar stations co-located Aerosol Robotic Network (AERONET) sunphotometers to help in the optical characterization. Here, we present the volcanic layer transported over São Paulo area and the detection of aerosol plume between 18 and 20 km. The path traveled by the volcanic aerosol to reach the Metropolitan Area of São Paulo (MASP) was tracked by CALIPSO and the aerosol optical and geometrical properties were retrieved at some points to monitor the plume evolution. Total attenuated backscatter profile at 532 nm obtained by CALIPSO revealed the height range extension of the aerosol plume between 18 and 20 km and are in agreement with SPU lidar range corrected signal at 532 nm. The daily evolution of Aerosol Optical Depth (AOD) at 532 and 355 nm, retrieved from AERONET sunphotometer, showed a substantial increasing on 27 April, the day of the volcanic plume detection at Metropolitan Area of São Paulo (MASP), achieving values of 0.33 0.16 and 0.22 0.09 at 355 and 532 nm, respectively. AERONET aerosol size distribution was dominated by fine mode aerosol over coarse mode, especially on 27 and 28 April. The space and time coincident aerosol extinction profiles from SPU lidar station and OMPS LP from the Calbuco eruption conducted on 27 April agreed on the double layer structure. The main objective of this study was the application of the transmittance method, using the Platt formalism, to calculate the optical and physical properties of volcanic plume, i.e., aerosol bottom and top altitude, the aerosol optical depth and lidar ratio. The aerosol plume was detected between 18 and 19.3 km, with AOD value of 0.159 at 532 nm and Ånsgtröm exponent of 0.61 0.58. The lidar ratio retrieved was 76 27 sr and 63 21 sr at 532 and 355 nm, respectively. Considering the values of these parameters, the Calbuco volcanic aerosol layers could be classified as sulfates with some ash type.

    Palavras-Chave: volcanoes; ashes; aerosols; boundary layers; atmospheric circulation; optical radar; south america; air quality

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  • IPEN-DOC 25828

    BETINI, E.G. ; GOMES, M.P. ; MILAGRE, M.X. ; MACHADO, C.S.C. ; REIS, L.A.M. ; MUCSI, C.S. ; ORLANDO, M.T.D.; LUZ, T.S.; MARTINEZ, L.G. ; ROSSI, J.L. . Study on welding thermal cycle and residual stress of UNS S32304 duplex stainless steel selected as external shield for a transport packaging of Mo-99. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-13, 2019. DOI: 10.15392/bjrs.v7i2A.679

    Abstract: Thin plates of duplex stainless steel UNS S32304 were welded using the pulsed gas tungsten arc GTAW process (butt joint) without filler addition. The used shielding gas was pure argon and 98% argon plus 2% of nitrogen. The thermal cycles were acquired during welding, in regions near the melting pool. This alloy is candidate for the external clad of a cask for the transport of high activity radiopharmaceuticals substances. For the residual stress measurements in austenite phase an X-ray diffractometer was used in a Bragg-Brentano geometry with CuKα radiation (λ= 0.154 nm) and for ferrite phase was used a pseudo-parallel geometry with CrKα radiation (λ= 0.2291nm). The results of residual stress using sin2 methodology showed that the influence of the high welding temperature leads to compressive stresses for both phases of the duplex steels mainly in the heat-affected zone. It was observed a high temperature peak and an increase of the mean residual stress after addition of ni-trogen to the argon shielding gas.

    Palavras-Chave: thermal cycling; molybdenum 99; containers; gas tungsten-arc welding; nitrogen; residual stresses; stainless steels; temperature range 0400-1000 k; x-ray diffractometers; radioactive materials

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  • IPEN-DOC 25827

    PUGLIESI, REYNALDO ; PEREIRA, MARCO A.S. ; ANDRADE, MARCOS L.G. ; BASSO, JULIANA M.L.; VOLTANI, CIBELE G.; GONZALES, IVONE C.. Study of the fish fossil Notelops brama from Araripe-Basin Brazil by Neutron Tomography. Nuclear Instruments and Methods in Physics Research, A, v. 919, p. 68-72, 2019. DOI: 10.1016/j.nima.2018.12.001

    Abstract: In the last decade, Neutron Tomography significantly gained importance as an analyzing tool to inspect samples of paleontological interest. In general, neutrons are able to provide new and complementary information when compared to the ones provided by X-rays imaging methods. Specifically, in the present paper, the Neutron Tomography equipment of the IPEN-CNEN/SP was successfully applied to investigate the internal structure of a fish fossil, embedded in a calcareous concretion. The resulting images, which will be presented, has revealed different contrast between several regions within the specimen enabling the differencing of osteological structures of the fossil, information about its state of conservation, degree of embedding, inclusions as well as regions within the concretion which could be related to humidity or to other substances and minerals containing hydrogen naturally added to the fossil. The technique is non-destructive and non-invasive allowing a close analysis of the specimen. Furthermore, the obtained images have demonstrated the feasibility of the equipment at IPENCNEN/ SP for investigating this kind of sample.

    Palavras-Chave: tomography; fossils; fishes; paleontology; neutron beams; brazil; brazilian cnen

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  • IPEN-DOC 25826

    FONTES, ERIC H. ; RAMOS, CARLOS E.D. ; NANDENHA, JULIO ; PIASENTIN, RICARDO M. ; OLIVEIRA NETO, ALMIR ; LANDERS, RICHARD. Structural analysis of PdRh/C and PdSn/C and its use as electrocatalysts for ethanol oxidation in alkaline medium. International Journal of Hydrogen Energy, v. 44, n. 2, p. 937-951, 2019. DOI: 10.1016/j.ijhydene.2018.11.049

    Abstract: The Pd/C, PdRh(50:50)/C and PdSn(50:50)/C nanomaterials were used as electrocatalysts for ethanol (EtOH) oxidation in Direct Ethanol Fuel Cell (DEFC) in an alkaline medium. This work aims to provide a complete physical characterization of the nanomaterials, elucidate the bifunctional mechanism concerning ethanol oxidation reaction and understand the influence of carbon e metal bonding in the electrochemical activity. These nanomaterials were investigated by X-ray photoelectron spectroscopy (XPS) and revealed that the atomic percentage of the surface is different of those obtained by Energy Dispersive X-ray spectroscopy (EDS). Raman spectroscopy showed a bonding between palladium and carbon atoms which can play a decisive role in the performance of the materials. Attenuated Total Reflectance technique coupled to the Fourier Transform Infrared spectroscopy (ATR-FTIR) made possible to investigate the oxidation products originated by the ethanol oxidation, and all the electrocatalysts showed the presence of acetaldehyde, carbonate ions, acetate and carbon dioxide, suggesting that the mechanism of oxidation is incomplete. Among all the nanomaterials studied, PdSn(50:50)/C showed the best electrochemical and Fuel Cell's results. It is about 33% better than Pd/C. The micrographs obtained by Transmission Electron Microscopy (TEM) revealed some agglomerate regions, but they are consistent with the literature data.

    Palavras-Chave: electrocatalysts; ethanol; x-ray diffraction; direct ethanol fuel cells; oxidation; nanomaterials; raman spectroscopy

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  • IPEN-DOC 25825

    LOPES, THIAGO ; BERUSKI, OTAVIO ; MANTHANWAR, AMIT M.; KORKISCHKO, IVAN ; PUGLIESI, REYNALDO ; STANOJEV, MARCO A. ; ANDRADE, MARCOS L.G. ; PISTIKOPOULOS, EFSTRATIOS N.; PEREZ, JOELMA; FONSECA, FABIO C. ; MENEGHINI, JULIO R.; KUCERNAK, ANTHONY R.. Spatially resolved oxygen reaction, water, and temperature distribution: experimental results as a function of flow field and implications for polymer electrolyte fuel cell operation. Applied Energy, v. 252, p. 1-13, 2019. DOI: 10.1016/j.apenergy.2019.113421

    Abstract: In situ and ex situ spatially-resolved techniques are employed to investigate reactant distribution and its impacts in a polymer electrolyte fuel cell. Temperature distribution data provides further evidence for secondary flows inferred from reactant imaging data, highlighting the contribution of convection in heat as well as reactant distribution. Water build-up from neutron tomography is linked to component degradation, matching the pattern seen in the reactant distribution and thus suggesting that high, non-uniform local current densities shape degradation patterns in fuel cells. The correlations shown between different techniques confirm the use of the versatile reactant imaging technique, which is used to compare commonly used flow field designs. Among serpentine-type designs, the single serpentine is superior in both equivalent current density and reactant distribution, showing large contributions from convective flow. On the other hand, the interdigitated design is shown to produce larger equivalent current densities, while showing a somewhat poorer reactant distribution. Considering the correlations drawn between the techniques, this suggests that the interdigitated design compromises durability in favour of power output. The results highlight how established techniques provide a robust background for the use of a new and flexible imaging technique toward designing advanced flow fields for practical fuel cell applications.

    Palavras-Chave: fuel cells; catalysts; layers; oxygen; temperature distribution; tomography

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  • IPEN-DOC 25824

    POLO, IVON O. ; JUNOT, DANILO O. ; CALDAS, LINDA V.E. . SOL-GEL α-Al2O3 samples: analysis of the TL kinetics. Journal of Applied Physics, v. 125, n. 18, p. 185102-1 - 185102-14, 2019. DOI: 10.1063/1.5088139

    Abstract: The analysis of the thermoluminiscence (TL) kinetics parameters of SOL-GEL α-Al2O3 with several different concentrations of impurities prepared through the solgel process is reported. A TL glow curve measured at 0.2 K/s after beta irradiation to 0.5 Gy revealed one peak at approximately 447 K. TL spectra were acquired and showed luminescent emission bands around 420 nm and 750 nm. The activation energies, the frequency factors, and the kinetic order involved in the TL emission were evaluated using the maximum peak temperature response, the peak shape of the TL glow curve, the TL glow curve area, and the glow curve fitting methods. The order of kinetics of the peak was evaluated as first order using TM dependence on the radiation dose. The (TM–Tstop) technique was used for determining the number of peaks in the glow curve. The activation energies obtained are in agreement with all the applied methods. The activation energy calculated by various methods varied from 0.885 ± 0.008 eV to 1.05 ± 0.10 eV. The frequency factor determined by all methods was of the order of 109 s−1. The dosimetric peak is affected by thermal quenching. The following thermal quenching parameters were estimated: the activation energy of the thermal quenching W= 1.05 ± 0.15 eV and the constant C = 8.27 × 1010 s−1. The trapping parameters of SOL-GEL α-Al2O3 detectors are reported in the present work for the first time.

    Palavras-Chave: sol-gel process; thermoluminescence; samplers; aluminium oxides; crystal structure; activation energy; emission spectra; rpl dosemeters

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  • IPEN-DOC 25823

    BATISTA, R.M. ; REIS, S.L. ; MUCCILLO, R. ; MUCCILLO, E.N.S. . Sintering evaluation of doped lanthanum gallate based on thermodilatometry. Ceramics International, v. 45, n. 5, p. 5218-5222, 2019. DOI: 10.1016/j.ceramint.2018.11.217

    Abstract: The sintering behavior of La0.9Sr0.1Ga0.8Mg0.2O3-δ oxide-ion conductor was systematically investigated by thermodilatometry. The shrinkage data obtained with heating rates of 4, 7, 10 and 12 °C min−1 were analyzed by the constant rate of heating model and by construction of the master sintering curve. Validation of the master sintering curve was carried out by measurements of density in conventionally sintered specimens. Slight anisotropy of shrinkage data was found and changes to the basic equation of density was proposed to account for this effect. Plotting the data determined by the constant rate of heating model versus density allowed an easy identification of the density range of constant activation energy. The activation energy (865 kJ mol−1) obtained from the master sintering curve correlates quite well with that (874 kJ mol−1) obtained by the constant rate of heating model.

    Palavras-Chave: sintering; oxides; gadolinium oxides; perovskites; fuel cells; ceramics; powders; lanthanum; doped materials

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  • IPEN-DOC 25822

    BEDOYA-VELASQUEZ, ANDRES E.; NAVAS-GUZMAN, FRANCISCO; MOREIRA, GREGORI de A. ; ROMAN, ROBERTO; CAZORLA, ALBERTO; ORTIZ-AMEZCUA, PABLO; BENAVENT-OLTRA, JOSE A.; ALADOS-ARBOLEDAS, LUCAS; OLMO-REYES, FRANCISCO J.; FOYO-MORENO, INMACULADA; MONTILLA-ROSERO, ELENA; HOYOS, CARLOS D.; GUERRERO-RASCADO, JUAN L.. Seasonal analysis of the atmosphere during five years by using microwave radiometry over a mid-latitude site. Atmospheric Research, v. 218, p. 78-89, 2019. DOI: 10.1016/j.atmosres.2018.11.014

    Abstract: This work focuses on the analysis of the seasonal cycle of temperature and relative humidity (RH) profiles and integrated water vapor (IWV) obtained from microwave radiometer (MWR) measurements over the mid-latitude city of Granada, southern Spain. For completeness the study, the maximum atmospheric boundary layer height (ABLHmax) is also included. To this end, we have firstly characterized the HATPRO-RPG MWR errors using 55 colocated radiosondes (RS) by means of the mean-bias (bias) profile and the standard deviation (SDbias) profile classified under all-weather conditions and cloud-free conditions. This characterization pointed out that temperature from HATPRO-MWR presents a very low bias respects RS mostly below 2.0 km agl, ranging from positive to negative values under all-weather conditions (from 1.7 to −0.4 K with SDbias up to 3.0 K). Under cloud-free conditions, the bias was very similar to that found under allweather conditions (1.8 to −0.4 K) but with smaller SDbias (up to 1.1 K). The same behavior is also seen in this lower part (ground to 2.0 km agl) for RH. Under all-weather conditions, the mean RH bias ranged from 3.0 to −4.0% with SDbias between 10 and 16.3% while under cloud-free conditions the bias ranged from 2.0 to −0.4% with SDbias from 0.5 to 13.3%. Above 2.0 km agl, the SDbias error increases considerably up to 4 km agl (up to −20%), and then decreases slightly above 7.0 km agl (up to−5%). In addition, IWV values from MWR were also compared with the values obtained from the integration of RS profiles, showing a better linear fit under cloudfree conditions (R2=0.96) than under all-weather conditions (R2=0.82). The mean bias under cloud-free conditions was −0.80 kg/m2 while for all-weather conditions it was −1.25 kg/m2. Thus, the SDbiasfor all the statistics (temperature, RH and IWV) of the comparison between MWR and RS presented higher values for allweather conditions than for cloud-free conditions ones. It points out that the presence of clouds is a key factor to take into account when MWR products are used. The second part of this work is devoted to a seasonal variability analysis over five years, leading us to characterize thermodynamically the troposphere over our site. This city atmosphere presents a clear seasonal cycle where temperature, ABLHmax and IWV increase from winter to summer and decrease in autumn, meanwhile RH decreases along the warmer seasons. This city presents cold winters (mean daily maximum temperature: 10.6 ± 1.1 °C) and dry/hot summers (mean daily maximum temperature of 28.8 ± 0.9 °C and mean daily maximum of surface RH up to 55.0 ± 6.0%) at surface (680m asl). Moreover, considering temporal trends, our study pointed out that only temperature and RH showed a linear increase in winters with a mean-rate of (0.5 ± 0.1) °C/year and (3.4 ± 1.7) %/year, respectively, from ground to 2.0 km agl, meanwhile IWV presented a linear increase of 1.0 kg·m−2/year in winters, 0.78 kg·m−2/year in summers and a linear decrease in autumns of −0.75 kg·m−2/year.

    Palavras-Chave: microwave radiation; atmospheres; seasonal variations; remote sensing; thermodynamic properties; boundary layers; radiometers

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  • IPEN-DOC 25821

    ALBUQUERQUE, C.R. ; MAIHARA, V.A. ; ALVES, C.B.L. ; SILVA, P.S.C. . Seaweed as a source of essential elements. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.687

    Abstract: Overtime seaweed species have been used as a food, mainly due to their high nutritional value. This type of food is considered as a functional food and it contributes to the nutritional human requirements, being beneficial to human health. In this study 13 edible seaweed samples acquired in São Paulo city markets were analyzed and the concentrations of Cl, K, Mg, Mn and Na were determined by Instrumental Neutron Activation Analysis (INAA). The following edible seaweed species were analyzed: Nori (Porphyra umbilicates); Hijiki (Hijikia fusiforme); Kombu (Laminaria sp.) and Wakame (Undaria pinnatifida) from China, USA, Japan and South Korea. Undaria pinnatifida species presented the highest Na concentration and the lowest K level. The highest concentration variation was obtained for Mn in the Porphyra umbilicates species.

    Palavras-Chave: seaweeds; elements; concentration; concentration ratio; neutron activation analysis; ecological concentration; quality control; aquatic organisms

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  • IPEN-DOC 25820

    SOUZA, CARLA D. de ; NOGUEIRA, BEATRIZ R. ; ROSTELATO, MARIA E.C.M. . Review of the methodologies used in the synthesis gold nanoparticles by chemical reduction. Journal of Alloys and Compounds, v. 798, p. 714-740, 2019. DOI: 10.1016/j.jallcom.2019.05.153

    Abstract: This paper presents a review in gold nanoparticles focusing on chemical reduction synthesis mechanisms. We hope to aid students and researchers starting in the nanotechnology field by compiling the most used synthesis methods, so they can select the ones that best suit them. The compiled information in this paper approached the following methods: Turkevich Method; Synthesis with NaBH4 with/without citrate; Seeding- Growth; Synthesis by Ascorbic Acid; Green Synthesis; Brust-Schiffrin; and synthesis using other reducing agents. Papers that had clear synthesis information were selected for this work, but that doesn't mean they were synthesis focused. Over 150 papers were analyzed. After compiling the information for these papers, we can conclude that nanoscience is revolutionizing all the areas that are applied to.

    Palavras-Chave: gold; nanoparticles; synthesis; chemical reactions; reduction; nanotechnology; citrates; sodium compounds; ascorbic acid; surfactants; borohydrides; bromides; seeds

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  • IPEN-DOC 25819

    CREMA, E.; ZAGATTO, V.A.B.; SHORTO, J.M.B. ; PAES, B.; LUBIAN, J.; SIMÕES, R.F.; MONTEIRO, D.S.; HUIZA, J.F.P.; ADDED, N.; MORAIS, M.C.; GOMES, P.R.S.. Reaction mechanisms of the O-16 + Cu-65 system. Physical Review C, v. 99, n. 5, p. 054623-1 - 054623-10, 2019. DOI: 10.1103/PhysRevC.99.054623

    Abstract: We have measured a precise quasielastic excitation function for the 16O + 65Cu system, at θLAB = 161◦, and at bombarding energies near the Coulomb barrier. A quasielastic barrier distribution for this system was deduced from the experimental quasielastic excitation function. An α-stripping excitation function has also been measured at the same experimental conditions. These new data have been used to investigate the relative importance of several reaction channels in the reaction mechanism of the 16O + 65Cu system. Large-scale coupled-channel calculations and coupled-reaction-channel calculations have been performed. No imaginary potential was used at the barrier region because many channels have been explicitly included in the calculations. Only an inner short-range potential was used to account for the fusion process. We did not fit data by varying potential parameters, and our theoretical results were compared directly to data. Good agreement was found between data and calculations. Owing to the high sensitivity of the barrier distribution, important results have been obtained. The first excited state (1/2−) of 65Cu has less influence in the reaction mechanism than the second (5/2−) and third (7/2−) states, which are the most relevant among all the investigated ones. We have also observed a striking influence of the reorientation of the ground-state spin of the 65Cu nucleus on the elastic scattering at backward angles. In addition, calculations have shown that the excitation of the states 3− , 2+ , 1−, and 2− of the projectile 16O are also important for excellent agreement obtained with both the excitation function and the distribution of barriers. The α-stripping data have been compared to the results of coupled-reaction-channel calculations and good agreement was obtained with the inclusion of the first excited state of 12C in the coupling scheme. However, the α-transfer process has a small influence on the reaction dynamics of this system at the investigated energies.

    Palavras-Chave: copper isotopes; oxygen 16 reactions; copper 65 target; elastic scattering; chemical reactions; theoretical data; experimental data

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  • IPEN-DOC 25817

    CRISTANTE, ALEXANDRE F.; BARBIERI, FABIO; SILVA, ALMY A.R. da; DELLAMANO, JOSE C. . Radiation exposure during spine surgery using C-arm fluoroscopy / Exposição a radiação durante cirurgias de coluna com radisocopia. Acta Ortopédica Brasileira, v. 27, n. 1, p. 46-49, 2019. DOI: 10.1590/1413-785220192701172722

    Abstract: Objective: To evaluate the radiation dose received by staff in spine surgeries, including those who are not considered occupationally exposed workers. Methods: All spinal surgeries performed in the same department during a period of 12 months were evaluated with regard to the exposure of surgeons, scrub nurses, and auxiliary personnel working in the operating room to radiation from C-arm fluoroscopy. Radiation was measured by 15 film badge dosimeters placed on the professionals’ lapels, gloves, and room standardized sites. The films were analyzed in the dosimetry laboratory by collections per period. Results: During the 12 months, 81 spinal surgeries were performed by the same team, with surgical times ranging from 1 to 6 hours. The total radiation dose ranged from 0.16 mSv to 2.29 mSv depending on the dosimetry site. The most exposed site was the wrist of the main surgeon. Conclusion: The results showed that in the spinal surgeries in our setting, the radiation doses are low and within legal limits. Nevertheless, constant training of professionals is essential for radiation protection of medical staff and patients. Level of evidence I/b, exploratory cohort study.

    Palavras-Chave: radiation absorption analysis; radiation doses; fluoroscopy; spinel; surgery

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  • IPEN-DOC 25816

    GUILHEN, S.N. ; MASEK, O.; ORTIZ, N. ; IZIDORO, J.C. ; FUNGARO, D.A. . Pyrolytic temperature evaluation of macauba biochar for uranium adsorption from aqueous solutions. Biomass and Bioenergy, v. 122, p. 381-390, 2019. DOI: 10.1016/j.biombioe.2019.01.008

    Abstract: This study aims to evaluate the effect of the pyrolytic temperature on the biochar derived from the macauba endocarp for the removal of uranium (VI) from aqueous solutions. The endocarp was subjected to six different pyrolytic temperatures, ranging from 250 °C to 750 °C. The biochars obtained at each temperature were evaluated for their adsorption capacities (“q”). The highest adsorption capacities were obtained for the biochar produced at 250 °C (BC250), followed by the one obtained at 350 °C (BC350), with removal efficiencies of 86% and 80%, respectively. The best condition was achieved when the endocarp was subjected to temperatures between 300 and 350 °C, at which it was possible to obtain a satisfactory balance among adsorption capacity, gravimetric yield and fixed carbon content. This characteristic, combined with the high removal efficiency, points to an ideal working temperature of 350 °C. Elemental analysis showed a decrease of the H/C and O/C ratios when higher pyrolytic temperatures were applied, indicating an inverse relationship between the carbonization and the surface polar functional groups, which were likely responsible for an increased adsorptive capacity in biochars produced at lower temperatures. Both FTIR and XPS analysis indicated that oxygen-containing groups such as hydroxyls and carboxylic acids were involved with the binding of uranyl ions.

    Palavras-Chave: biomass; carbon; pyrolysis; pyrolytic carbon; temperature dependence; radioactive wastes; uranium; adsorption; coconut palms

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  • IPEN-DOC 25815

    VESELOVSKII, IGOR; GOLOUB, PHILIPPE; HU, QIAOYUN; PODVIN, THIERRY; WHITEMAN, DAVID N.; KORENSKIY, MIKHAEL; LANDULFO, EDUARDO . Profiling of CH4 background mixing ratio in the lower troposphere with Raman lidar: a feasibility experiment. Atmospheric Measurement Techniques, v. 12, n. 1, p. 119-128, 2019. DOI: 10.5194/amt-12-119-2019

    Abstract: We present the results of methane profiling in the lower troposphere using LILAS Raman lidar from the Lille University observatory platform (France). The lidar is based on a frequency-tripled Nd:YAG laser, and nighttime profiling up to 4000 with 100m height resolution is possible for methane. Agreement between the measured photoncounting rate in the CH4 Raman channel in the free troposphere and numerical simulations for a typical CH4 background mixing ratio (2 ppm) confirms that CH4 Raman scattering is detected. The mixing ratio is calculated from the ratio of methane (395.7 nm) and nitrogen (386.7 nm) Raman backscatters, and within the planetary boundary layer, an increase of the CH4 mixing ratio, up to a factor of 2, is observed. Different possible interfering factors, such as leakage of the elastic signal and aerosol fluorescence, have been taken into consideration. Tests using backscattering from clouds confirmed that the filters in the Raman channel provide sufficient rejection of elastic scattering. The measured methane profiles do not correlate with aerosol backscattering, which corroborates the hypothesis that, in the planetary boundary layer, not aerosol fluorescence but CH4 is observed. However, the fluorescence contribution cannot be completely excluded and, for future measurements, we plan to install an additional control channel close to 393 nm, where no strong Raman lines exist and only fluorescence can be observed.

    Palavras-Chave: raman spectroscopy; optical radar; troposphere; methane; feasibility studies

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  • IPEN-DOC 25814

    DURAZZO, M. ; UMBEHAUN, P.E. ; TORRES, W.M. ; SOUZA, J.A.B. ; SILVA, D.G. ; ANDRADE, D.A. . Procedures for manufacturing an instrumented nuclear fuel element. Progress in Nuclear Energy, v. 113, p. 166-174, 2019. DOI: 10.1016/j.pnucene.2019.01.021

    Abstract: The IEA-R1 is an open pool research reactor that operated for many years at 2 MW. The reactor uses plate type fuel elements which are formed by assembling eighteen parallel fuel plates. During the years of reactor operation at 2 MW, thermohydraulic safety margins with respect to design limits were always very high. However, more intense oxidation on some external fuel plates was observed when the reactor power was increased to 5 MW. At this new power level, the safety margins are significantly reduced due to the increase of the heat flux on the plates. In order to measure, experimentally, the fuel plate temperature under operation, an instrumented fuel element was constructed to obtain temperature experimental data at various positions of one or more fuel plates in the fuel element. The manufacturing method is characterized by keeping the original fuel element design specifications. Type K stainless sheathed thermocouples are mounted into supports pads in unrestricted positions. During the fuel element assembling, the supports pads with the thermocouples are mechanically fixed by interference between two adjacent fuel plates. The thermocouple wires are directed through the space existing at the bottom of the mounting slot where the fuel plate is fixed to the side plates. The number of thermocouples installed is not restricted and depends only on adaptations that can be made on the mounting slots of the standard fuel element side plates. This work describes the manufacturing procedures for assembling such an instrumented fuel element.

    Palavras-Chave: fuel elements; iear-1 reactor; research reactors; fuel plates; fuel fabrication plants; thermocouples

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  • IPEN-DOC 25813

    ZAHN, GUILHERME S. ; RIBEIRO JUNIOR, IBERE S. ; GENEZINI, FREDERICO A. . Pile-up correction for coincidence counting using a CAEN 1724 digitizer. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-10, 2019. DOI: 10.15392/bjrs.v7i2A.578

    Abstract: In conventional gamma-ray spectrometry, the probability of pile-up effects is considered to be proportional to the dead-time, and is usually neglected for low dead-times (below 4-5%). In gamma-gamma coincidence spectrometry, though, while the dead time takes into account only events that are actually digitized, the pile-up effects are proportional to the actual gamma-ray detection rate in each detector, not only to the ones that trigger the coincidence gate. Thus, the pile-up corrections may not be so easy to assess as in single spectrometry systems. In this work, a system composed of two HPGe detectors coupled to a CAEN v1724 digitizer is studied. A 3kBq 60Co source was analyzed, both alone and in the presence of other radioactive sources (137Cs, 133Ba and 152Eu), and the resulting coincidence peak areas were compared to assess the effectiveness of two distinct corrections: a simple normalization by the live time of acquisition and the normalization by the count rate obtained using a pulse generator. The results obtained stress the need to use the pulse generator in this specific setup in order to get accurate results.

    Palavras-Chave: corrections; digitizers; data acquisition; dead time; gamma radiation; barium 133; europium 152; cesium 137; cobalt 60; data acquisition; high-purity ge detectors; pulse pileup

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  • IPEN-DOC 25812

    BARROSO, ALINE G.; MASTRO, NELIDA L. del . Physicochemical characterization of irradiated arrowroot starch. Radiation Physics and Chemistry, v. 158, p. 194-198, 2019. DOI: 10.1016/j.radphyschem.2019.02.020

    Abstract: The term arrowroot is used for the starch obtained from the rhizomes of Maranta arundinacea. In the present work effects of 60Co radiation treatment (dose up to 15 kGy) on structural characteristics and pasting properties of arrowroot starch were evaluated. Thermal properties, granule size and shape and size distribution, by means of optical and scanning electron microscopy and Fourier transform IR (FTIR) spectra were also obtained. On pasting properties strong decrease in peak and final viscosities, as well as breakdown, were observed. In the dose range applied, minimal changes in crystallinity, molecular composition and structure of arrowroot starch were found.

    Palavras-Chave: starch; cassava; physical chemistry; irradiation; gamma radiation; thermodynamic properties; thermal analysis; food

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  • IPEN-DOC 25811

    BORBOREMA, SAMANTA E.T. ; OSSO JUNIOR, JOAO A. ; ANDRADE JUNIOR, HEITOR F. de; NASCIMENTO, NANCI do . Pharmacokinetics of neutron-irradiated meglumine antimoniate in Leishmania amazonensis-infected BALB/c mice. Journal of Venomous Animals and Toxins including Tropical Diseases, v. 25, p. 1-9, 2019. DOI: 10.1590/1678-9199-JVATITD-1446-18

    Abstract: Background: Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach. Methods: Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured. Results: Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice. Conclusions: neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.

    Palavras-Chave: parasitic diseases; protozoa; antimony; radioisotopes; chemotherapy; bioassay

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  • IPEN-DOC 25810

    ALVARENGA, LETICIA H.; GOMES, ANA C.; CARRIBEIRO, PAMELA; GODOY-MIRANDA, BIANCA; NOSCHESE, GIOVANE; RIBEIRO, MARTHA S. ; KATO, ILKA T.; BUSSADORI, SANDRA K.; PAVANI, CHRISTIANE; GERALDO, YHAGO G.E.; SILVA, DANIELA de F.T. da; HORLIANA, ANNA C.R.T.; WAINWRIGHT, MARK; PRATES, RENATO A.. Parameters for antimicrobial photodynamic therapy on periodontal pocket: randomized clinical trial. Photodiagnosis and Photodynamic Therapy, v. 27, p. 132-136, 2019. DOI: 10.1016/j.pdpdt.2019.05.035

    Abstract: Background: Antimicrobial photodynamic therapy (aPDT) has been investigated as an adjunctive to periodontal treatment but the dosimetry parameters adopted have discrepancies and represent a challenge to measure efficacy. There is a need to understand the clinical parameters required to obtain antimicrobial effects by using aPDT in periodontal pockets. The aim of this study was to investigate parameters relating to the antimicrobial effects of photodynamic therapy in periodontal pockets. Material and methods: This randomized controlled clinical trial included 30 patients with chronic periodontitis. Three incisors from each patient were selected and randomized for the experimental procedures. Microbiological evaluations were performed to quantify microorganisms before and after treatments and spectroscopy was used to identify methylene blue in the pocket. A laser source with emission of radiation at wavelength of ʎ=660 nm and output radiant power of 100mW was used for 1, 3 and 5 min. One hundred μM methylene blue was used in aqueous solution and on surfactant vehicle. Results: The results demonstrated the absence of any antimicrobial effect with aqueous methylene blue-mediated PDT. On the other hand, methylene blue in the surfactant vehicle produced microbial reduction in the group irradiated for 5 min (p < 0.05). Spectroscopy showed that surfactant vehicle decreased the dimer peak signal at 610 nm. Conclusion: Within the parameters used in this study, PDT mediated by methylene blue in a surfactant vehicle reached significant microbial reduction levels with 5 min of irradiation. The clinical use of PDT may be limited by factors that reduce the antimicrobial effect. Forms of irradiation and stability of the photosensitizers play an important role in clinical aPDT.

    Palavras-Chave: methylene blue; antimicrobial agents; dosimetry; clinical trials; therapy; dentistry; bacteria; irradiation; absorption

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  • IPEN-DOC 25809

    AZEVEDO, JULIANA de S.; HORTELLANI, MARCOS A. ; SARKIS, JORGE E. de S. . Organotropism of total mercury (THg) in Cichla pinima, ecological aspects and human consumption in fish from Amazon region, Brazil. Environmental Science and Pollution Research, v. 26, p. 21363-21370, 2019. DOI: 10.1007/s11356-019-05303-x

    Abstract: Specimens of the Cichla pinima are of ecological and economic importance in the Amazon region and are a good bioindicator species of Hg bioaccumulation. Adult specimens of Cichla pinima were obtained by fisheries in the Tapajós river region’s impacted gold mining area. Tissues such as muscle, liver, skin, and gill were submitted for total mercury (THg) analysis. For hepatic bioavailability, assays were carried out in the whole liver and in the sub-cellular hepatic fraction. The weight–length relationship showed an equation ofW= 2E− 06L3.3002 (R2 = 0.856) indicating an allometric growth. The mean THg values found in the muscle tissue of 676 ± 258 μg kg−1 were below the maximum limit established for human consumption, but were similar to Cichla fish from other areas impacted by Hg in the Amazon region. The trends of levels in the tissues were as follows: liver>muscle>gonads>skin>gill, with no significant differences between the gills and skin. A significant and positive correlation as rs = 0.65 was obtained between the THg contents in cytosolic fraction and the total hepatic THg (liver homogenate). However, only 7% of the THg were found and were available to the sub-cellular hepatic fraction. This profile can be an indicative of a hepatic cellular transference in fish exposed to high Hg levels in the Amazon region now that low concentrations of Hg have been found in the sub-cellular fraction. However, data of differential THg partition in the subcellular compartments should be considered, since others’ hepatic fractions can act in the Hg linkage into the cell.

    Palavras-Chave: fishes; amazon river; brazil; mercury; concentration ratio; environmental impacts

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  • IPEN-DOC 25808

    LEITE, ANTONIO M. dos S. ; TERADA, MAYSA; PEREIRA, VICTOR F.; FONSECA, EDUARDO B. da; LIMA, NELSON B. de ; COSTA, ISOLDA . On the pitting resistance of friction stir welded UNS S82441 lean duplex stainless steel. Journal of Materials Research and Technology, v. 8, n. 3, p. 3223-3233, 2019. DOI: 10.1016/j.jmrt.2019.05.010

    Abstract: Friction stir welding has been considered as an alternative to fusion welding processes ofstainless steels. A lean duplex stainless steel, grade UNS S82441, has been recently developedand is prone to localized corrosion, such as pitting when exposed to harsh conditions duringuse. However, pitting resistance of UNS S82441 has not been previously investigated. In thisstudy, UNS S82441 lean duplex stainless steel was friction stir welded, and its microstructureand localized corrosion resistance were investigated by phase volumetric fraction, scanningelectron microscopy, transmission electron microscopy and electrochemical tests. The pit-ting resistance of each zone was investigated by polarization tests and by determining thecritical pitting temperature. The results indicated that microstructural changes promotedby friction stir welding affected the pitting resistance of the lean duplex stainless steel.

    Palavras-Chave: pitting corrosion; corrosion resistance; friction; stainless steels; friction welding; austenitic steels; transmission electron microscopy

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  • IPEN-DOC 25807

    GOMES, MAURILIO P. ; COSTA, ISOLDA ; PEBERE, NADINE; ROSSI, JESUALDO L. ; TRIBOLLET, BERNARD; VIVIER, VINCENT. On the corrosion mechanism of Mg investigated by electrochemical impedance spectroscopy. Electrochimica Acta, v. 306, p. 61-70, 2019. DOI: 10.1016/j.electacta.2019.03.080

    Abstract: This work reported a detailed analysis of the electrochemical impedance spectra obtained for the Mg electrode during immersion in a sodium sulfate solution. A model was proposed which took into account the presence of: (i) a thin oxide film (MgO) which progressively covered the Mg electrode surface, (ii) film-free areas where the Mg dissolution occurs in two consecutive steps, (iii) a thick layer of corrosion products (Mg(OH)2), (iv) an adsorbed intermediate ðMgþ ads Þ which is responsible for the chemical reaction allowing the negative difference effect to be explained. From the impedance data analysis, various parameters were extracted such as the thin oxide film thickness, the resistivity at the metal/oxide film interface and at the oxide film/electrolyte interface, the active surface area as a function of the exposure time to the electrolyte, the thickness of the thick Mg(OH)2 layer and the kinetic constants of the electrochemical reaction.

    Palavras-Chave: corrosion; impedance; spectroscopy; electrochemical corrosion; magnesium; tin oxides; adsorption

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  • IPEN-DOC 25806

    PARALOVO, SARAH L.; BARBOSA, CYBELLI G.G.; CARNEIRO, ISABELA P.S.; KURZLOP, PRISCILA; BORILLO, GUILHERME C.; SCHIOCHET, MARIA F.C.; GODOI, ANA F.L.; YAMAMOTO, CARLOS I.; SOUZA, RODRIGO A.F. de; ANDREOLI, RITA V.; RIBEIRO, IGOR O.; MANZI, ANTONIO O.; KOURTCHEV, IVAN; BUSTILLOS, JOSE O.V. ; MARTIN, SCOT T.; GODOI, RICARDO H.M.. Observations of particulatematter, NO2, SO2, O3, H2S and selected VOCs at a semi-urban environment in the Amazon region. Science of the Total Environment, v. 650, p. 996-1006, 2019. DOI: 10.1016/j.scitotenv.2018.09.073

    Abstract: This research aims to assess air quality in a transitional location between city and forest in the Amazon region. Located downwind of the Manaus metropolitan region, this study is part of the large-scale experiment GoAmazon2014/5. Based on their pollutant potential, inhalable particulate matter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), hydrogen sulfide (H2S), benzene, toluene, ethylbenzene and meta-, orto-, para-xylene (BTEX) were selected for analysis. Sampling took place during the wet season (March–April 2014) and dry season (August–October 2014). The number of forest fires in the surroundings was higher during the dry wet season. Results show significant increase during the dry season in mass concentration (wet: b0.01–10 μg m−3 ; dry: 9.8–69 μg m−3 ), NH4 + soluble content (wet: 13–125 μg m−3 ; dry: 86–323 μg m−3 ) and K+ soluble content (wet: 11–168 μg m−3 ; dry 60–356 μg m−3 ) of the PM2.5, and O3 levels (wet: 1.4–14 μg m−3 ; dry: 1.0–40 μg m−3 ), indicating influence of biomass burning emissions. BTEX concentrations were lowin both periods, but also increased during the dry season. Aweak correlation in the time series of the organic and inorganic gaseous pollutants indicates a combination of different sources in both seasons and NO2 results suggest a spatial heterogeneity in gaseous pollutants levels beyond initial expectations.

    Palavras-Chave: air quality; brazil; amazon river; forests; urban areas; biomass; statistical data; particulates; air pollution monitoring; environmental effects

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  • IPEN-DOC 25805

    MANTECON, JAVIER G. ; MATTAR NETO, MIGUEL . Numerical analysis on stability of nuclear fuel plates with inlet support comb. Nuclear Engineering and Design, v. 342, p. 240-248, 2019. DOI: 10.1016/j.nucengdes.2018.12.009

    Abstract: Many nuclear research reactors use or are planned with cores containing flat-plate-type fuel elements. One of the problems of this fuel element design is the mechanical stability of the fuel plates. High-velocity coolant flowing through the narrow channels that separate the plates can cause large deflections of these plates leading to local overheating, structural failure or plate collapse. In particular, in real fuel elements and experimental tests, flowinduced deflections at the leading edge and along the length of the plates have been detected. Some authors have indicated that the use of a support comb removes the leading-edge static divergence, but it has been also suggested that, even with the comb, there are significant deflections away from the inlet. In this work, a fluid-structure interaction study is conducted to examine the effectiveness of using an inlet comb on the mechanical stability of fuel plates. The system consists of two fuel plates bounded by three-equal coolant channels. The pressure loadings caused by the fluid flow are calculated using a CFD model and the structural response of the plates and the support comb are determined by means of an FEA model. The two-way fluid-structure interaction method was employed for coupling the fluid and solid solvers. The results presented here show that the static divergence at the inlet end is effectively eliminated with the installation of a support comb. Nevertheless, the main contribution of this work is the detection of deformation of the plates along their length and that it was an increasing function of the fluid velocity in the channels. As a consequence, the flow channels could be constricted or completely closed, thus affecting the safe operation of the nuclear reactor. To the best of our knowledge, this is the first numerical analysis reported in the literature that models the fluid-structure interaction phenomenon of adjacent plates with the support comb located at the midpoint of their inlet end.

    Palavras-Chave: fuel plates; fuel elements; critical velocity; fluid-structure interactions; numerical data; nuclear fuels

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  • IPEN-DOC 25804

    ASSIS, IGOR M. de; MORAES, MARIA O.S. de; CONCEIÇÃO, RELEM C. da; ROMAGUERA-BARCELAY, YONNY; SOUZA, RODRIGO F.B. de ; LARRUDE, DUNIESKYS R.G.; ROCCO, MARIA L.M.; BRITO, WALTER R.. Novel electrochemical sensor based on molecularly imprinted polymer for selective recognition of sesquiterpene β-caryophyllene. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, v. 217, p. 271-277, 2019. DOI: 10.1016/j.saa.2019.03.097

    Abstract: Molecularly imprinted polymers provide an excellent platform for the modification of selective electrodes for sensing applications. Herein, we present a novel modified carbon paste electrode (CPE) with a selectivemolecularly imprinted polymer (MIP) for recognition of sesquiterpene β-caryophyllene, constituted of important plants oil-resins and extracts. The non-covalentMIPwas synthesized using AA, EGDMA, and AIBNas a functional monomer, cross-linker and initiator agent, respectively. Structural and chemical characterization of the synthesized MIP was conducted through scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). It was possible to verify the functional features of the synthesized MIP related to the extraction process of the template molecule. The CPE modified withMIP for sesquiterpene β-caryophyllene recognition was characterized by electrochemical techniques as cyclic voltammetry (CV) and squarewave voltammetry (SWV). The highest selective recognition electrode enables to detect concentrations in the range between 1.5 × 10−7 and 7.5 × 10−7 M, showing great potential for applications in monitoring content of sesquiterpene β-caryophyllene in technological processes and for predicting the quality of extracts, oils, and resins of plants.

    Palavras-Chave: polymers; raman spectra; scanning electron microscopy; terpenes; electrodes; polymers; sensors; plants; resins; oils; organic polymers

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  • IPEN-DOC 25803

    REGO, ULISSES A. do; LOPES, THIAGO ; BOTT-NETO, JOSE L.; GOMEZ-MARIN, ANA M.; TANAKA, AURO A.; TICIANELLI, EDSON A.. Non-noble Fe-Nx/C electrocatalysts on tungsten carbides/N-doped carbons for the oxygen reduction reaction. Electrocatalysis, v. 10, n. 2, p. 134-148, 2019. DOI: 10.1007/s12678-018-0503-1

    Abstract: This work investigates the influence of different nitration protocols of a carbon black, the addition of tungsten carbide (WC), and the presence of iron, in terms of the catalytic activity of electrocatalysts containing Fe-Nx moieties towards the oxygen reduction reaction (ORR) in acidic and alkaline media. The synthesized materials were characterized using X-ray diffraction (XRD), Raman spectroscopy (Raman), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) with a rotating ring-disk electrode (RRDE), in addition to durability tests. In acidic media, the performance of the catalysts varied according to the type of nitration protocol, the presence of iron, and the heat treatment temperature, which is accompanied by variations in the ORR mechanism. In alkaline electrolyte, the electrocatalysts presented higher performances, with only an ~0.04-V difference relative to that of a standard platinum on carbon catalyst. The number of electrons transferred per oxygen molecule, the amounts of hydrogen peroxide generated in the ORR, the effect of catalyst loading, and the presence of iron in the catalysts were investigated with the aim of understanding the ORR mechanism and assisting in the production of high-performance and durable materials. Finally, the two best electrocatalysts were submitted to a standard durability test, which evidenced promising high stability at both pHs.

    Palavras-Chave: electrocatalysts; nitration; redox reactions; tungsten carbide; raman spectra; electrochemistry; iron; carbon black; nitrogen

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  • IPEN-DOC 25802

    PACHECO, R.R.; FREIRE, L.O. ; ROCHA, M.S. ; SCURO, N.L. ; MENEZES, M.O. ; ANDRADE, D.A. . New formulation for semi-empirical correlations for penetration jets. World Journal of Nuclear Science and Technology, v. 9, n. 2, p. 96-111, 2019. DOI: 10.4236/wjnst.2019.92007

    Abstract: Correlations for the extension of a water vapor jet injected in a liquid pool were historically proposed considering the mass flux (kg/m2/s) as a constant. The results were satisfactory, however adjusting the values by linear regression. Although, it presents the following drawbacks: 1) the formulation is only valid for the specific range of data for what it was created; 2) it does not allow the analytical evaluation of the heat transfer coefficient from the extension equation. This paper proposes a new formulation for the calculation of the mass flux, in such a way to remove both of these drawbacks.

    Palavras-Chave: water vapor; vapor jet ejectors; steam jet ejectors; reynolds number; heat transfer; vapor condensation; boiling

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  • IPEN-DOC 25801

    TAPPIZ, B. ; MOREIRA, E.G. . Neutron activation analysis characterization procedures for fish consumed at São Paulo city. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.710

    Abstract: The characterization of edible tissues of fishes consumed by humans is very important for determination of sev-eral toxic and potentially toxic elements, ensuring the food safety. The Instrumental Neutron Activation Analysis (INAA) comparative method allows the determination of several of these elements, as well as others, for example of nutritional character. This study is part of an International Atomic Energy Agency (IAEA) technical coopera-tion project of Latin America and Caribbean countries to ensure the quality of food and biomonitoring of con-taminants in shellfish and fishes. Ten specimens of 4 of the most consumed fish in São Paulo city: whitemouth croaker (Micropogonias Furnieri), smooth weakfish (Cynoscion learchus), common snook (Centropomus undeci-malis) and Brazilian sardine (Sardinella brasiliensis) were analyzed. Complete procedures for analysis, which includes purchase in the largest warehouse in Latin America, transport to the laboratory, storage, freeze-drying, milling, weighting and others preparations of the subsamples, and the short irradiation parameters for the de-termination of Br, Cl, K, Mg, Mn and Na are reported. Results obtained under the same irradiation conditions for reference materials (oyster and mussel tissues) for macro and microelements are presented and are in agreement with their certificates, which indicate that the performed analyses were appropriate. Regarding to the mass fraction values obtained for the fish samples, they were in agreement with the literature.

    Palavras-Chave: neutron activation analysis; fishes; brazil; contamination; gamma spectroscopy; quality assurance; quality management; high-purity ge detectors; radioisotopes; food; quality control

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  • IPEN-DOC 25800

    DIMMER, JESICA; CABRAL, FERNANDA V. ; SABINO, CAETANO P. ; SILVA, CAMILA R. ; NUNEZ-MONTOYA, SUSANA C.; CABRERA, JOSE L.; RIBEIRO, MARTHA S. . Natural anthraquinones as novel photosentizers for antiparasitic photodynamic inactivation. Phytomedicine, v. 61, n. 152894, p. 1-7, 2019. DOI: 10.1016/j.phymed.2019.152894

    Abstract: Background: Cutaneous leishmaniasis (CL) is a vector-borne disease caused by obligate protist parasites from the genus Leishmania. The potential toxicity as well as the increased resistance of standard treatments has encouraged the development of new therapeutical strategies. Photodynamic inactivation (PDI) combines the use of a photosensitizer and light to generate reactive oxygen species and kill cells, including microorganisms. Vegetal kingdom constitutes an important source of bioactive compounds that deserve to be investigated in the search of naturally occurring drugs with leishmanicidal activity. Purpose: The purpose of this study was to test the antiparasitic activity of PDI (ApPDI) of five natural anthraquinones (AQs) obtained from Heterophyllaea lycioides (Rusby) Sandwith (Rubiacae). To support our results, effect of AQ mediated-PDI on parasite´s morphology and AQ uptake were studied. Cytotoxicity on fibroblasts was also evaluated. Study design/Methods: Two monomers, soranjidiol (Sor) and 5-chlorosoranjidiol (5-ClSor) plus three bi-anthraquinones (bi-AQs), bisoranjidiol (Bisor), 7-chlorobisoranjidiol (7-ClBisor) and Lycionine (Lyc) were selected for this study. Recombinant L. amazonensis promastigote strain expressing luciferase was subjected to AQs and LED treatment. Following irradiation with variable light parameters, cell viability was quantified by bioluminescence. Alteration on parasite's morphology was analyzed by scanning electron microscopy (SEM). In addition, we verified the AQ uptake in Leishmania cells by fluorescence and their toxicity on fibroblasts by using MTT assay. Results: Bisor, Sor and 5-ClSor exhibited photodynamic effect on L. amazonensis. SEM showed that promastigotes treated with Bisor-mediated PDI exhibited a significant alteration in shape and size. Sor and 5-ClSor presented higher uptake levels than bi-AQs (Bisor, Lyc and 7-ClBisor). Finally, Sor and Bisor presented the lowest toxic activity against fibroblasts. Conclusion: Taking together, our results indicate that Sor presents the highest specificity towards Leishmania cells with no toxicity on fibroblasts.

    Palavras-Chave: parasitic diseases; anthraquinones; antimitotic drugs; therapy; photosensitivity; inactivation; monomers

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  • IPEN-DOC 25799

    SILVA, P.S.C. ; SEMMLER, R. ; ZAHN, G.S. ; ROCHA, F.R. ; DAMATTO, S.R. ; FAVARO, D.I.T. . Natural and artificial nuclides in Salesópolis reservoir. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.657

    Abstract: Natural radioactivity is ubiquitous in the environment mainly due to the presence of the nuclides from the ura-nium and thorium series and 40K. Although in the South Hemisphere nuclear tests have been fewer in number than that in the North, artificial radionuclides can also be found spread at ground level. In this study, the activity concentrations of natural nuclides from the uranium and thorium series, 40K and the artificial 137Cs were deter-mined in a sediment core with 42 cm depth collected in the middle of the Salesópolis reservoir, located in the Metropolitan Region of São Paulo city (SPMR). The Usina Parque Rio Tietê reservoir belongs to the Alto do Tietê system for the capture, storage and treatment of water for SPMR. Therefore, the quality of the water and sediments of this dam is of great importance. The activity concentrations were measured by gamma spectrome-try. Samples were measured and saved at regular intervals at a maximum of 160 000 seconds. The gross area were determined for each peak and plotted against time and the counting rate was obtained by the slope of the curve. Background and reference materials were also counted and treated in the same way. Results showed that 226Ra varied from 45 to 116 Bq kg-1; 228Ra, from 80 to 165 Bq kg-1; 40K, from 155 to 1 187 Bq kg-1 and 137Cs varied from 0.3 to 7 Bq kg-1. The methodology applied for determining low levels of 137Cs in sediment proved to be effi-cient and reproducible.

    Palavras-Chave: natural radioactivity; water reservoirs; uranium; thorium; potassium 40; cesium 137; sediments; brazil; radioisotopes; gamma spectroscopy; water quality

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  • IPEN-DOC 25798

    LOPES, A.C.O.; COELHO, P.G.; WITEK, L.; BENALCAZAR JALKH, E.B.; GENOVA, L.A. ; MONTEIRO, K.N.; CESAR, P.F.; LISBOA FILHO, P.N.; BERGAMO, E.T.P.; RAMALHO, I.S.; BONFANTE, E.A.. Nanomechanical and microstructural characterization of a zirconiatoughened alumina composite after aging. Ceramics International, v. 45, n. 7, p. 8840-8846, 2019. DOI: 10.1016/j.ceramint.2019.01.211

    Abstract: This study's objective was to mechanically characterize and validate the synthesis method of a polycrystalline composite comprised of 80% alumina reinforced with 20% translucent zirconia (zirconia-toughened alumina, ZTA) and compare to an experimental translucent zirconia. Experimental ZTA (ZTA ZPEX 80/20) and translucent Y-TZP (ZPEX) green-state disc-shaped specimens were obtained via uniaxial/isostatic ceramic powder pressing technique. The discs were sintered using a predefined protocol after both sides of the discs were polished. The specimens were subjected to nanoindentation testing to acquire their elastic modulus (E) and hardness (H) before and after a simulated low temperature degradation (LTD) challenge. Subsequently, the fabricated discs had their 3D surface topographical (Sa/Sq) parameters assessed via interferometry before and after exposure to a simulated LTD aging protocol. The specimens were evaluated using X-ray diffraction (XRD) to assess the tetragonal-monoclinic phase transformation and via scanning electron microscopy (SEM) to evaluate the homogeneity of the surfaces and distribution of the grains. The apparent density was measured using Archimedes’ principle. All of the data were statistically evaluated through repeated measures ANOVA following post-hoc comparisons using the Tukey test (p < 0.05). The XRD patterns indicated a higher increase in the monoclinic peak for ZPEX compared to ZTA ZPEX 80/20 aged. LTD aging did not have an effect on the surface roughness (Sa/Sq) for both groups (p > 0.05). A significant decrease in the E values after the aging protocol was observed for both groups (p < 0.01). While ZTA ZPEX 80/ 20 did not show statistically significant differences in the hardness values after the aging protocol (p=0.36), ZPEX demonstrated a significant decrease in the H values (p=0.03). For ZTA ZPEX 80/20, simulated LTD aging did not affect the tested properties, except for the E values. Although artificial aging did not affect the surface roughness of ZPEX, the E and H values significantly decreased after aging.

    Palavras-Chave: microstructure; composite materials; mechanical properties; zirconium oxides; aluminium oxides; nanostructures; synthesis; aluminates

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  • IPEN-DOC 25797

    POLO, IVON O. ; SANTOS, WILLIAM S. ; CALDAS, LINDA V.E. . Monte Carlo modeling of a holder for irradiation of dosimeters in beta radiation beams. Applied Radiation and Isotopes, v. 143, p. 60-66, 2019. DOI: 10.1016/j.apradiso.2018.10.020

    Abstract: A study of the influence of a dosimetric holder and its cover for the irradiation of the dosimeters in the Beta Secondary Standard BSS2 radiation fields is reported. The correction factors for attenuation or scattering were calculated taking into account the BSS2 beta source energy, as well as the detector source distance. The study and the determination of these factors were carried out using the Monte Carlo Method. The results of the correction factors showed that the absorption and scattering of the electrons depend greatly on the energy of beta radionuclides. The determined correction factors are in agreement with the international report ISO 6980.

    Palavras-Chave: monte carlo method; radiation sources; attenuation; radiation protection; dosemeters; scattering

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  • IPEN-DOC 25796

    CORDEIRO, THIAGO da S. ; AMARAL, MARCELLO M.; MATOS, RICARDO A. de; SILVA, FLAVIA R.O. ; VIEIRA JUNIOR, NILSON D. ; COURROL LILIA C.; ROSSI, WAGNER de ; SAMAD, RICARDO E. . Modifying the second order dispersion of femtosecond laser pulses to crack silver nanoparticles and control their dimensions. Optics and Laser Technology, v. 118, p. 1-7, 2019. DOI: 10.1016/j.optlastec.2019.04.034

    Abstract: The potential application of metallic nanoparticles had been attracting attention and interest from different areas of academia and industry. The nanoparticles properties and applications depend heavily on their dimension and shape, thus special interest is aimed to controlling the nanoparticles sizes. Ultrashort laser pulses are known to change metallic nanoparticles characteristics, but the interaction mechanism is still not completely understood. In this work we reduced the dimension of silver nanoparticles with ultrashort pulses and demonstrated that there is a dependence of the particles size on the second order dispersion introduced in the pulses, which became smaller as the dispersion becomes more negative. Based on the results, we propose that the Coulomb explosion that reduces the nanoparticles size is predominantly initiated by multiphotonic ionization for the intensities used (1014 W/cm2).

    Palavras-Chave: nanoparticles; nanomaterials; lasers; silver; spectroscopy

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  • IPEN-DOC 25795

    FERREIRA, NELSON D.; LEAL NETO, RICARDO M. ; FILGUEIRA, MARCELLO; FERREIRA, LUCAS M.; ALVES, MANUEL F.R.P.; RAMOS, ERIKA C.T.; NUNES, CARLOS A.; SANTOS, CLAUDINEI dos; RAMOS, ALFEU S.. Microstructure and Vickers hardness of mechanically alloyed and spark plasma sintered Ti-2Zn-22Si-11B and Ti-6Zn-22Si-11B alloys. Journal of Alloys and Compounds, v. 794, p. 615-624, 2019. DOI: 10.1016/j.jallcom.2019.04.172

    Abstract: This work reports on effect of zinc and milling time on microstructure and Vickers hardness of mechanically alloyed and spark plasma sintered (66,7-x)Ti-xZn-22,2Si-11,1B alloys (at.-%, with x ¼ 2 and 6 at.-%). Ball milling at different times (20, 60, 180 and 300 min) was performed under argon atmosphere in a planetary ball mill from these elemental powder mixtures. Cylinder bodies with 10mm diameter were consolidated by spark plasma sintering (1100 C, 12 min, 20MPa) under argon atmosphere. Asmilled powders and sintered Ti-Zn-Si-B samples were evaluated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, laser diffraction particle size analysis, and Vickers hardness tests. It was noted a similar behavior during ball milling of Ti-Zn-Si-B powder mixtures. Only the a-Ti and Si peaks were indexed in XRD patterns of Ti-Zn-Si-B powders milled for 300min. Rietveld refining indicated that the amount of amorphous structures has increased during milling up to 300 min, which was more pronounced for the Ti-6Zn-22Si-11B powders. The particle sizes of the Ti-2Zn-22Si-11B and Ti-6Zn-22Si-11B powder mixtures increased during milling from 94 (20 min) to 156 (300min) mm and from 101 (20 min) to 136 (300 min) mm, respectively. Coherently, the average specific surface area of powder particles was continuously reduced during milling. Despite the adopted parameters, the SPS process produced dense Ti-xZn-22Si-11B (x ¼ 2 and 6 at.-%) alloys with 98% from their theoretical specific mass. Regardless of milling time, the Ti6Si2B formation was inhibited in microstructure of the spark plasma sintered Ti-6Zn-22Si-11B alloy previously milled for longer times. EDS analysis indicated that the Ti6Si2B phase dissolved close to 1.8 at.-% Zn. Beside the TiB and Ti5Si3, the Ti2Zn and Ti3Zn (not explored) phases were also found in microstructure of sintered Ti-Zn-Si-B alloys. The Ti-2Zn-22Si-11B alloy presented average Vickers hardness values higher than 1050 HV whereas the Ti-6Zn-22Si-11B alloy varied between 970 and 1036 HV, which could be associated with the Ti6Si2B formation.

    Palavras-Chave: zinc; titanium alloys; vickers hardness; plasma; sintering; microstructure; healing; bone mineral density

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  • IPEN-DOC 25793

    SOUZA, ARMANDO C. ; ARISTONE, FLAVIO; ROSSI, JESUALDO L. ; MARTINEZ, LUIS G. ; CIONE, FRANCISCO C. ; TSAKIROPOULOS, PANOS; GRANDINI, CARLOS R.; SILVA, WALLACE F. da. Microstructural characterization of Zr1Nb alloy after hot rolling. International Journal of Refractory Metals & Hard Materials, v. 80, p. 216-224, 2019. DOI: 10.1016/j.ijrmhm.2018.12.015

    Abstract: The nuclear industries have large interest on the development of new alloys involving zirconium (Zr) because this material presents extraordinary mechanical properties, outstanding resistance to corrosion and high permeability to thermal neutrons, being suitable for applications in areas such as energy and human health. The alloy studied in this paper is formed by Zr and niobium (Nb), normally expressed as Zr1Nb. These two elements have large chemical affinities with oxygen, carbon, and nitrogen, elements that normally are responsible for a series of damages in the alloy. The principal goal of this work is to obtain Zr1Nb alloys and to perform microstructural characterizations before and after the hot rolling process. The resulting alloys were subjected to a process of heat treatment, the temperature was increased at a rate of 10 K/min up to 1273 K and maintained for 2 h, after which it was cooled down at −10 K/min until room temperature, with the only purpose of relieving residual stresses. The next step was to apply the hot rolling process to the alloy. The sample initially measured, approximately, 1.5 cm of thickness when it was inserted into the furnace at 1203 K to start the hot rolling. Every pass on the hot rolling reduced the thickness by 0.5 mm, originating uniform and homogeneous samples of 2.5mm thickness. Auxiliary technical tools, such as XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy), and EDS (Energy Dispersive X-Ray Spectroscopy), were used to analyze the microstructure of the samples before and after the hot rolling process. The XRD results show the formation of only a single α-HCP (Hexagonal Close Packed) phase for our samples, indicating that they are free of other phases that can damage the material. This result is consistent and coherent with both SEM and EDS analysis. The observed homogeneity of our samples is very good; proving that both techniques employed to obtain Zr1Nb as well as the hot rolling process was well succeeded. Therefore, the obtained alloy can be directly used in the pipes of nuclear combustible industries.

    Palavras-Chave: microstructure; zirconium alloys; niobium alloys; nitrites; oxide minerals; transition element alloys; melting; rolling

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  • IPEN-DOC 25792

    RESTIVO, THOMAZ A.G. ; BECCARI, RAFAEL F.; PADILHA, WELLINGTON R.; DURAZZO, MICHELANGELO ; TELLES, VICTOR B.; COLETI, JORGE; YAMAGATA, CHIEKO ; SILVA, ANTONIO C. da ; SUZUKI, EDUARDO; TENORIO, JORGE A.S.; MELLO-CASTANHO, SONIA R.H. . Micrograded ceramic-metal composites. Journal of the European Ceramic Society, v. 39, n. 12, p. 3484-3490, 2019. DOI: 10.1016/j.jeurceramsoc.2019.03.018

    Abstract: The article shows new designed cermets and processes concerning primary to applications as thermal insulation materials with low emissivity. A new projected microstructure was obtained where dense regions (micropellets) rest inside the main porous pellet. The feature resembles a frozen hypercube, therefore such architecture is called hyper-pellet/ cermet. The processing method to obtain the hyper-cermet is based on sequential tape castings and sintering techniques. Ni-zirconia lamellae were prepared by a special mechanochemical process followed by sintering, which remain inside the main pellets as a dense region. The whole pellet is turned to be porous by employing pore-forming additives. All the constituents and porosity shapes are aligned along the disc/ flake planes. Thermal conductivity is estimated for the materials up to 800 °C by a flash diffusivimeter. Ceramographic analyses show graded density regions with directional constituents and pores. Applications of such materials are foreseen as temperature insulation materials and thermal radiation shields.

    Palavras-Chave: cermets; ceramics; radiations; shields; thermal insulation; emissivity; heat transfer; thermal conductivity

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  • IPEN-DOC 25791

    CASTRO, L. ; MOREIRA, E.G. ; VASCONCELLOS, M.B.A. . Micro-homogeneity evaluation of a bovine kidney candidate reference material. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.576

    Abstract: The minimum sample intake for which a reference material remains homogeneous is one of the parameters that must be estimated in the homogeneity assessment study of reference materials. In this work, Instrumental Neutron Activation Analysis was used to evaluate this quantity in a bovine kidney candidate reference material. The mass fractions of 9 inorganic constituents were determined in subsamples between 1 and 2 mg in order to estimate the relative homogeneity factor (HE) and the minimum sample mass to achieve 5% and 10% precision on a 95% confidence level. Results ob-tained for HE in all the analyzed elements were satisfactory. The estimated minimum sample intake was between 2 mg and 40 mg, depending on the element.

    Palavras-Chave: neutron activation analysis; kidneys; cattle; gamma spectra; irradiation; calibration standards; intake; high-purity ge detectors; homogenates

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  • IPEN-DOC 25789

    VILLIBOR, FERNANDA F.; GUILHEN, SABINE N. ; DANTAS, ELIZABETH S.K. ; PIRES, MARIA A.F. . Mercury exposure among dental staff in the legal Amazon / Exposição a mercúrio entre profissionais da área odontológica na Amazônia legal. Brazilian Journal of Health Review, v. 2, n. 4, p. 2530-2544, 2019. DOI: 10.34119/bjhrv2n4-025

    Abstract: Elemental mercury is highly toxic and may be absorbed by dental professionals through direct skin contact or inhalation. The use of mercury in dental amalgam has been a concern of the academic community for years, for its incorporation is likely to affect vital organ systems. Several studies have been conducted to address the possible risks of occupational exposure to mercury vapor in dental offices. The present study aimed to present evidences that mercury is assimilated by exposed workers through the determination of urinary mercury (HgU) from dental professionals (n = 91) of public offices in Araguaína (Tocantins, Brazil). This uptake was verified against samples from unexposed individuals (n = 43), which activities are not dentistry related. Cold vapor atomic absorption spectrometry (CV-AAS) technique enabled the subjects’ biological monitoring. Approximately 44.8% (n = 60) of the 134 participants were aged between 21 and 30 years and were at the beginning of their professional lives; 9.7% (13) of the study participants were men and 90.3% (121) were women. Hg concentrations in all samples analyzed were within the maximum biological limit set by the World Health Organization (WHO) (<50 μgHg·L−1). HgU concentrations in dental professionals were within the limits proposed by the Brazilian regulatory standard, Regulatory Norm-7 (RN-7) (≤35 μgHg·g−1 creatinine). Nevertheless, the average concentration of HgU was approximately 8 times higher in the potentially exposed group (5.61 μgHg·g−1 creatinine) than in the unexposed group (0.65 μgHg·g−1 creatinine), highlighting the potential risk of occupational exposure to mercury.

    Palavras-Chave: mercury; occupational exposure; dentistry; mercury alloys; monitoring; absorption spectroscopy; validation; brazil

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  • IPEN-DOC 25788

    OLIVEIRA, MAURO M. de ; COUTO, ANTONIO A. ; ALMEIDA, GISELE F.C. ; REIS, DANIELI A.P.; LIMA, NELSON B. de ; BALDAN, RENATO. Mechanical behavior of Inconel 625 at elevated temperatures. Metals, v. 9, n. 3, p. 1-13, 2019. DOI: 10.3390/met9030301

    Abstract: Inconel 625 is a nickel-based alloy that is mainly used in high-temperature applications. Inconel 625 exhibits an unstable plastic flow at elevated temperatures characterized by serrated yielding, well-known as the Portevin-Le Chatelier effect. The evaluation of the mechanical properties of Inconel 625 at high temperatures is the aim of this work. The tensile tests were executed in temperatures ranging from room temperature to 1000 C with strain rates of 2 10􀀀4 to 2 10􀀀3 s􀀀1. The creep tests were executed in the temperature range of 600–700 C and in the stress range of 500–600 MPa in a constant load mode. The optical and scanning electron microscopes were used for surface fracture observation. In the curves obtained at 200–700 C the serrated stress-strain behavior was observed, which was related to the dynamic strain aging effect. The yield strength and the elongation values show anomalous behavior as a function of the test temperature. An intergranular cracking was observed for a specimen tensile tested at 500 C that can be attributed to the decohesion of the carbides along the grain boundaries. The fracture surface of the specimen tensile tested at 700 C showed the predominance of transgranular cracking with tear dimples with a parabolic shape.

    Palavras-Chave: inconel 625; nickel alloys; temperature range 1000-4000 k; strain aging; mechanical properties; tensile properties; deformation

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  • IPEN-DOC 25787

    SÁ, A.P.N. ; GOES-FAVONI, S.S.P.; GIANNONI, J.A.; ARTHUR, V.; VILLAVICENCIO, A.L.C.H. . Irradiation effect on lipid oxidation index on okara-based soybean flour. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-10, 2019. DOI: 10.15392/bjrs.v7i2A.662

    Abstract: Seasoned flour, also known as “farofa”, is a low cost industrialized product easy to prepare, which may be enriched with nutrients in order to improve its nutritional value. Typically, it’s made from maize or yuca tem-pered flour. However, soy seasoned flour (SSF), which is made from okara (inert-flavored-mass obtained as a residue from the soybean extract), is a viable alternative for nutritional enrichment in relation to the previous conventional tempered flour. This work aimed to reuse a by-product of processing of soybean okara to elaborate soy-seasoned flour and to analyze the possible effect of gamma irradiation at doses of 1 and 3 kGy, in the analy-sis of determination of lipid peroxidation. The preparation of SSF containing okara, dehydrated condiments and flavor uplifting proceeded at FATEC Marília. SSF samples were processed at “Centro de Energia Nuclear na Agricultura” (CENA), University of Piracicaba-SP, and irradiated with doses of 1 and 3 kGy in 60Co source. The dose rate was 0.269/h. Analysis were performed to determine the peroxide index of control samples and irra-diated in triplicate at 1, 15, 30 and 45 storage days according to the methodology for oils and fats with modifica-tions. Using this peroxide methodology, it was not detected changes in oxidative quality in the samples, whatever was the storage period. The flour having as a parameter 29.92% of lipids. We conclude that this product have excellent nutritional attributes regards to the conventional flour, though we must apply a different methodology to detect any radiation damage on lipid compounds using doses up to 3kGy.

    Palavras-Chave: soybeans; radiation effects; food processing; flour; ionizing radiations; lipids; radiation doses; preservation; dose rates; cobalt 60; oxidation; peroxides

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  • IPEN-DOC 25786

    VILLANI, D. ; DORES, D.R.S.A.; SILVA, V.R. da; COSTA, Z.M. da; CAMPOS, L.L. . Investigations on luminescence properties of erbium-doped phosphate glass produced at Juiz de Fora Federal University. Radiation Measurements, v. 125, p. 29-33, 2019. DOI: 10.1016/j.radmeas.2019.04.005

    Abstract: Rare Earth doped-phosphate glasses have received a great deal of attention on research because of their applications in biomaterial engineering, however, little to no attention has been given to potential luminescent properties from “heating” these materials when exposed to ionizing radiation. This paper aims to presents results on investigations of Thermoluminescent (TL) and Optically Stimulated Luminescence (OSL) properties of the Er3+-doped phosphate glasses produced at the Physics Department of Federal University of Juiz de Fora on a characterization for beta radiation dosimetry. It was used a RISØ TL/OSL reader and its coupled 90Sr/90Y beta source. The experimental findings indicate that the material presents linear responses of thermo (TL) and optically stimulated luminescence (OSL) over the absorbed dose range of 2 to 20Gy. Its emitted TL and OSL signal is more intense and with extended linearity range compared with undoped phosphate glass, probably caused by two absorption bands on 350–380 nm from Er3+. Further investigations are being carried out on its applications to other types and qualities of radiation.

    Palavras-Chave: thermoluminescence; luminescence; dosimetry; rare earths; erbium; phosphate glass; beta dosimetry; ionizing radiations

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  • IPEN-DOC 25784

    GUILHEN, S.N. ; COLETI, J.; TENORIO, J.A.S.; FUNGARO, D.A. . Influence of adsorption parameters on uranium adsorption capability by biochar derived from macauba coconut residue. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.590

    Abstract: Biochar (BC) is a carbon-rich product obtained when biomass is thermally decomposed at relatively low temperatures (under 700ºC) and limited supply of oxygen in a process called pyrolysis. Because of its porous structure, charged sur-face and surface functional groups, BC exhibits a great potential as an adsorbent. Its characteristics strongly depend on the feedstock and the pyrolysis conditions. The aim of this study was to evaluate the adsorption potential for the remov-al of uranium, U(VI) from aqueous solutions using BC obtained through slow pyrolysis of the macauba coconut endo-carp. The influence of parameters such as pH, sorbent dose and initial concentration on the adsorption of U(VI) was investigated. The BC obtained at 350 °C (BC350) presented a removal percentage of approx. 80 %, demonstrating its applicability for the treatment of uranium contaminated aqueous solutions.

    Palavras-Chave: adsorption; uranium; chars; biological materials; concentration ratio; coconut palms; temperature dependence; waste water; pyrolysis; ph value

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  • IPEN-DOC 25783

    DAGUANO, JULIANA K.M.B.; MILESI, MARIANA T.B.; RODAS, ANDREA C.D.; WEBER, ALINE F.; SARKIS, JORGE E.S. ; HORTELLANI, MARCOS A. ; ZANOTTO, EDGAR D.. In vitro biocompatibility of new bioactive lithia-silica glass-ceramics. Materials Science & Engineering C, v. 94, p. 117-125, 2019. DOI: 10.1016/j.msec.2018.09.006

    Abstract: Glass-ceramics based on the Li2O-SiO2 system have been extensively used as restorative dental materials due to their excellent chemical durability, aesthetics, inertness in the buccal environment, and high fracture strength; but they are not bioactive. On the other hand, all known bioactive glasses show ability to bond to bone, teeth and cartilage coupled to osteoconduction and osteoinduction, but their fracture strength and toughness are rather low. The aim of this study is to develop and evaluate the in vitro biocompatibility of a new type of (bioactive and strong) lithia-silica glass-ceramic. For these purposes, two types of glass-ceramics based on a multicomponent lithia-silica system were studied: lithium metasilicate (LM) and lithium disilicate (LD). The in vitro bioactivity study was conducted in a SBF solution, before and after different times of immersion; the new materials were analyzed by XRD, FTIR, and SEM. Some samples were subjected to in vitro biodegradation tests to quantify the release of lithium and the weight loss. Cytotoxicity, adhesion, and cell proliferation on different samples were examined by using the Methyl Tetrazolium salt (MTS) and Alizarin Red. For ~40 vol% crystallinity, lithium metasilicate was detected as the major phase, whereas for ~80 vol% crystallinity, lithium disilicate was the major phase. The LD proved to be strong (3p-bending strength of 233 ± 12 MPa) and bioactive after 14 days of immersion in SBF. In terms of lithium ion release, the LD was outside the toxic range (> 8.3 ppm). The LM and LD are not cytotoxic. The LD shows the best cellular adhesion and proliferation, leading to the formation of a mineralized matrix after 21 days. These results clearly suggest that the new LD brand is strong and highly biocompatible and warrants further study.

    Palavras-Chave: biology; compatibility; dentistry; teeth; biological regeneration; in vitro; crystallization; lithium; ceramics; glass

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  • IPEN-DOC 25782

    WETTER, NIKLAUS U. ; SILVA, DIEGO S. da; KASSAB, LUCIANA R.P.; JIMENEZ-VILLAR, ERNESTO . Improving performance in ytterbium-erbium doped waveguide amplifiers through scattering by large silicon nanostructures. Journal of Alloys and Compounds, v. 794, p. 120-126, 2019. DOI: 10.1016/j.jallcom.2019.04.141

    Abstract: Optical waveguide amplifiers have seen a growing interest in the last years due to their applications in telecommunication. This paper reports a notable increase of the relative gain of Yb3þ/Er3þ codoped Bi2O3 eGeO2 waveguides by introducing disorder in the form of silicon nanostructure as scattering centers. A photoluminescence enhancement of about 10 times for the 520 nm and 1530 nm emission bands is observed in the waveguides when the silicon nanostructures are introduced. Increase of the Yb3þ/Er3þ effective absorption, due to the scattering provided by the silicon nanostructures, and decrease of [Biþ], caused by the introduction of silicon, are proposed as likely causes for the luminescence and gain enhancement. The pedestal waveguides were fabricated by RF-sputtering followed by optical lithography and reactive ion etching. RF-sputtering of silicon together with Yb/Er and Bi2O3eGeO2 glass, followed by heat treatment, produced Yb3þ/Er3þ codoped Bi2O3eGeO2 waveguides with silicon nanostructures of size 25e30 nm. The resulting relative gain reached 5.5 dB/cm at 1542 nm representing an enhancement of 50% with respect to waveguides without silicon nanostructures. This strategy of introducing appropriate disorder may open an avenue for designing and manufacture of novel photonic devices in this emerging field of integrated optics.

    Palavras-Chave: ytterbium; erbium; doped materials; nanostructures; optical properties; sputtering; amplifiers; scanning electron microscopy

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  • IPEN-DOC 25781

    MUCCILLO, R. ; MUCCILLO, E.N.S. . Improved densification and ionic conductivity in flash-sintered gamma-ray irradiated yttria-stabilized zirconia. Scripta Materialia, v. 170, p. 120-123, 2019. DOI: 10.1016/j.scriptamat.2019.06.004

    Abstract: Experiments on electric field-assisted pressureless sintering were conducted, with a dilatometer connected to a power supply, in zirconia: 8 mol% yttria polycrystalline ceramics exposed to gamma radiation. During heating to 1000 °C, an electric field of 150 V cm−1 was applied at room temperature up to a sharp thickness shrinkage occurred (flash sintering). It was found that the higher the imparted gamma radiation dose the higher the shrinkage. The shrinkage enhancement and the increase of the total ionic conductivity, when compared to nonirradiated sample, were probably due to the increase of oxygen vacancy concentration after exposure to gamma radiation.

    Palavras-Chave: ionic conductivity; irradiation; zirconium oxides; sintering; yttrium; gamma radiation; heating

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  • IPEN-DOC 25780

    VELO, A.F. ; ALVAREZ, A.G. ; HAMADA, M.M. ; MESQUITA, C.H. . Image quality analysis of an industrial instant non-scanning tomography system with different collimators. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.561

    Abstract: An instant non-scanning tomography system is being developed at the IPEN. This type of tomography system, due to its configurations, provides a low spatial resolution; however, it presents a high temporal resolution as an advantage. In this sense, it has high applicability in industrial processes involving dynamic multiphase processes, like distillation columns. Thereby, to obtain the best conditions of image acquisition, this tomography system comprising different collimators was simulated with Monte Carlo using the MCNP4C.The image quality was evaluated with Matlab® 2013b analyzing the contrast to noise ratio (CNR), root mean square ratio (RMSE), signal to noise ratio (SNR) and the spatial resolution by the Modulation Transfer Function (MTF(f)), to identify which collimator fits better to the tomography in development. It was simulated three situations; (i) with no collimator; (ii) ø 25x 50 mm2 cylindrical collimator with a septum of ø5.0 x 50 mm2; (iii) ø25 x 50 mm2 cylindrical collimator with a slit septum of 24 x 5.0 x 50 mm3. RMSE values for no collimator presented better results. CNR showed that no collimator and slit collimator reaches the same CNR values, but no collimator decreases more than the slit collimator as the number of iteration rises. The hole collimator reaches a higher CNR value, however decreases more than the others. The spatial resolution with no collimator and slit collimator were around 31.9 mm, and for the hole collimator was around 20 mm.

    Palavras-Chave: collimators; tomography; computerized tomography; computerized simulation; monte carlo method; quality assurance; quality management; image processing; nai detectors; signal-to-noise ratio; radiation detectors; radiation detectors; industrial plants; brazilian cnen

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  • IPEN-DOC 25778

    MACHI, ANDRE R. ; MAYNE, RAQUEL R.; GAVA, MARCIO A.; ARTHUR, PAULA B. ; ARTHUR, VALTER . Gamma radiation sterilization dose of adult males in Asian tiger mosquito pupae. Insects, v. 10, n. 4, p. 1-11, 2019. DOI: 10.3390/insects10040101

    Abstract: The pathogen-carrying tiger mosquito, Aedes albopictus, has spread from theWestern Pacific and Southeast Asia to Europe, Africa, the Middle East, North and South America, and the Caribbean. This species of mosquito transmits arboviral infections, such as yellow fever, chikungunya, dengue, zika, and several encephalitides. The objective of this research was to provide a radiation dose inducing sterilization in adult male Ae. albopictus in the pupal stage. A cobalt-60 source of gamma radiation at a dose rate of 381 Gy/h was used. The pupae were irradiated with doses of 0 (control), 20, 30, 40, 50, and 60 Gy. Each treatment had a total of five replications using 60 pupae. After irradiation, the different phases of Ae. albopictus development (egg, larva, pupa, and adult) in the F1 generation were observed daily. Parameters such as viability, fertility, longevity, and mortality were recorded. The results from these studies showed that a dose of 60 Gy was necessary to sterilize 100% of the male Ae. albopictus pupae.

    Palavras-Chave: gamma radiation; sterilization; mosquitoes; viruses; ionizing radiations; radiation effects; cobalt 60; viral diseases; radiation doses

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  • IPEN-DOC 25777

    MESQUITA, C.H. de ; CALVO, W.A.P. ; AOKI, P.E. ; SILVA, V.C. da ; HARAGUCHI, M.I. ; VELO, A.F. ; ALVAREZ, A.G. ; HAMADA, M.M. . Gallium-67 citrate used as a tracer of acetone production routes. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.562

    Abstract: In this work the pathway of the chemical product and the kinetics parameters were evaluated in a laboratory plant settled, using 0.4 GBq (10 mL) of 67Ga citrate as radiotracer and 18 NaI(Tl) radiation detectors. The AnaComp program was used to estimate the kinetic para ameters of the acetone production. The yield of the acetone production was estimated by the percentage ratio between the areas under the curve (AUC) of the curve profiles of the final product compartment divided by the concentration found inside the chemical reactor whose result was 87% yield during the first 30 minutes of reaction.

    Palavras-Chave: gallium 67; citrates; multi-channel analyzers; acetone; nai detectors; tracer techniques; calibration; radioactivity; kinetics

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  • IPEN-DOC 25775

    RAELE, MARCUS P. ; DE PRETTO, LUCAS R. ; ROSSI, WAGNER de ; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Focus tracking system for femtosecond laser machining using low coherence interferometry. Scientific Reports, v. 9, p. 1-8, 2019. DOI: 10.1038/s41598-019-40749-6

    Abstract: We designed a real time, single-laser focus tracking system using low coherence properties of the machining femtosecond laser itself in order to monitor and correct the sample position relative to the focal plane. Using a Michelson Interferometer, the system collects data arising from part of the beam backscattered at the ablation spot. The data is analyzed by a custom software for position correction (employing an XYZ automated translation stage). With the focus tracking enabled we were able to etch channels with a stable cross-section profile on a bovine tooth with relief amplitude tens of times greater than the Rayleigh length of the system, keeping the sample inside the confocal parameter during most of the processing time. Moreover, the system is also capable of monitoring crater depth evolution during the ablation process, allowing for material removal assessment.

    Palavras-Chave: interferometry; laser radiation; michelson interferometer; laser beam machining; ablation; optical systems

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  • IPEN-DOC 25774

    BARBEZAN, ANGELICA B. ; SANTOS, CARLA J.B. ; CARVALHO, LUMA R. ; VIEIRA, DANIEL P. ; SANTELLI, GLAUCIA M.M.; VILLAVICENCIO, ANNA L.C.H. . Flow cytometry based micronucleus assay for evaluation of genotoxic potential of 2-ACBs in hepatic cells HepG2. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-24, 2019. DOI: 10.15392/bjrs.v7i2A.684

    Abstract: Food irradiation is approved for use in more than 60 countries for applications and purposes in a wide variety of foods, being an effective and safe method for preservation and long-term storage. 2- Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated from foods that contain fatty acids (Triglycerides) when irradiated. The acids analyzed in this study are palmitic and stearic, which when irradiated form 2-Dodecylcyclobutanones (2-dDCB) and 2-Tetradecylcyclobutanone (2-tDCB). Part of the 2-ACBs ingested is excreted through feces and part is deposited in adipose tissues. In vitro studies so far have been only in colon cells. The work used a human hepatoma cell line (HepG2) since the accumulation of fat in this organ is quite common. Micronucleus test was selected to evaluate possible genotoxic effects of 2-dDCB and 2-tDCB compounds when exposed to high concentrations (447, 1422 and 2235 μM) for 4 and 24 hours. Tests were performed in quadriplicates using flow cytometric analysis. None detectable genotoxic damage was observed after 4 hours of exposure to the compounds, and cytotoxic effects were only significant at the highest concentration (2235 μM) of 2-dDCB. After 24 hours of exposure, slight genotoxic damage was observed at all concentrations evaluated, and cytotoxic effects were only present when exposed to compound 2-tDCB. Although there is a genotoxic and cytotoxic effect in some of the situations tested, the two compounds predominantly induced proliferation reduction effects of this hepatic tumor cell line.

    Palavras-Chave: food processing; irradiation; hexadecanoic acid; cell flow systems; dodecyl radicals; hepatomas; in vitro; octadecanoic acid; radiation effects; toxicity; carcinomas

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  • IPEN-DOC 25773

    MUCCILLO, REGINALDO ; FERLAUTO, ANDRE S.; MUCCILLO, ELIANA N.S. . Flash sintering samaria-doped ceria-carbon nanotube composites. Ceramics, v. 2, n. 1, p. 64-73, 2019. DOI: 10.3390/ceramics2010006

    Abstract: Composite ceramic green pellets were prepared by attrition milling a mixture of (CeO2)0.8(Sm2O3)0.2 (samaria-doped ceria, SDC) ceramic powder and carbon nanotubes (CNTs), followed by uniaxial and isostatic pressing. The pellets were sintered inside a dilatometer by applying AC electric fields at 850 C and limiting the electric current to 1 A, achieving 20.2% final shrinkage. The SDC samples reached 13.3% shrinkage under the same conditions. Higher average grain sizes were measured in specimens flash sintered with CNTs. Impedance spectroscopy analyses show that the specimens flash sintered with addition of CNTs have higher electrical conductivity. Higher delivered Joule heating at the interfaces due to the presence of the electronic conductors (CNTs) are proposed as the main reason for that improvement of the electrical behavior.

    Palavras-Chave: samarium oxides; cerium oxides; solid oxide fuel cells; doped materials; sintering; spectroscopy; nanotubes; composite materials

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  • IPEN-DOC 25772

    NASCIMENTO, C.R.; ASFORA, V.K.; BARROS, V.S.M.; GONCALVES, J.A.C. ; ANDRADE, L.F.R.; KHOURY, H.J.; BUENO, C.C. . Feasibility studies of using thin entrance window photodiodes for clinical electron beam dosimetry. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2A.577

    Abstract: The response of the commercial XRA-24 PIN photodiode (5.76 mm2 active area) for clinical electron beam dosimetry covering the range of 8-12 MeV was investigated. Within this energy range, the charge generated in the diode’s sensitive volume is linearly dependent on the absorbed dose up to 320 cGy. However, charge sensitivity coefficients evidenced that the dose response of the diode is slightly dependent on the electron beam energy. Indeed, the diode’s energy dependence was within 8.5% for 8-12 MeV electron beams. On the other hand, it was also observed an excellent repeatability of these results with a variation coefficient (VC) lower than 0.4%, which is within the 1% tolerance limit recommended by the AAPM TG-62. Furthermore, the agreement between the percentage depth dose profiles (PDD) gathered with the diode and the ionization chamber allowed achieving the electron beam quality within 1% of that obtained with the ionization chamber. Based on these results, the photodiode XRA-24 can be a reliable and inexpensive alternative for electron beams dosimetry.

    Palavras-Chave: dosimetry; electron beams; feasibility studies; ionization chambers; photodiodes; depth dose distributions; energy dependence; mev range 01-10; silicon diodes

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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.