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  • IPEN-DOC 26529

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

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


  • IPEN-DOC 26528

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

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


  • IPEN-DOC 26527

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

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


  • IPEN-DOC 26521

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

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


  • IPEN-DOC 26523

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

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


  • IPEN-DOC 26522

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

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


  • IPEN-DOC 26515

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


  • IPEN-DOC 26507

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


  • IPEN-DOC 26503

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


  • IPEN-DOC 26463

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

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


  • IPEN-DOC 26434

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

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


  • IPEN-DOC 26520

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

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


  • IPEN-DOC 26450

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

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


  • IPEN-DOC 26448

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

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


  • IPEN-DOC 26519

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

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


  • IPEN-DOC 26518

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

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


  • IPEN-DOC 26516

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

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


  • IPEN-DOC 26514

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

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


  • IPEN-DOC 26513

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

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


  • IPEN-DOC 26512

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

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


  • IPEN-DOC 26511

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

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


  • IPEN-DOC 26510

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

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


  • IPEN-DOC 26509

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

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


  • IPEN-DOC 26508

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

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


  • IPEN-DOC 26506

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

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


  • IPEN-DOC 26505

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

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


  • IPEN-DOC 26504

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

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


  • IPEN-DOC 26502

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

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


  • IPEN-DOC 26501

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

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


  • IPEN-DOC 26497

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

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


  • IPEN-DOC 26495

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

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


  • IPEN-DOC 26494

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

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


  • IPEN-DOC 26493

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

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


  • IPEN-DOC 26490

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

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


  • IPEN-DOC 26488

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

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


  • IPEN-DOC 26487

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

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


  • IPEN-DOC 26486

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

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


  • IPEN-DOC 26485

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

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


  • IPEN-DOC 26483

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

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


  • IPEN-DOC 26482

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

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


  • IPEN-DOC 26481

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

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


  • IPEN-DOC 26480

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

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


  • IPEN-DOC 26479

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

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


  • IPEN-DOC 26478

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

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


  • IPEN-DOC 26477


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


  • IPEN-DOC 26476

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

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


  • IPEN-DOC 26475

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

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


  • IPEN-DOC 26474

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

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


  • IPEN-DOC 26473

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

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


  • IPEN-DOC 26472

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

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


  • IPEN-DOC 26471

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

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


  • IPEN-DOC 26470

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

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


  • IPEN-DOC 26469

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

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


  • IPEN-DOC 26468

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

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


  • IPEN-DOC 26467

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

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


  • IPEN-DOC 26466

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

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


  • IPEN-DOC 26465

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

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


  • IPEN-DOC 26462

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

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


  • IPEN-DOC 26461

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

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


  • IPEN-DOC 26460

    URIOSTE, ARIEL; ZAJAC, MARIA A.L.; AQUINO, SIMONE ; RIBEIRO, ANDREZA P.. Logística reversa de explantes cirúrgicos em um hospital filantrópico: implantação de um novo modelo ecoeficiente de gerenciamento de resíduo hospitalar / Reverse logistics of surgical explant in a philanthropic hospital: implementation of a new ecoefficient model of management hospital waste. Revista de Gestão em Sistemas de Saúde, v. 7, n. 3, p. 257-273, 2018. DOI: 10.5585/rgss.v7i3.415

    Abstract: Explantes cirúrgicos são dispositivos metálicos que foram implantados cirurgicamente em pacientes e que depois de retirados seguem uma destinação diferenciada dos demais resíduos hospitalares, já que devem ser submetidos ao processo de esterilização para serem considerados resíduos sem risco biológico. O presente estudo teve como objetivo implantar um sistema de gerenciamento de descarte de explantes cirúrgicos, após um diagnóstico realizado por meio do uso parcial da ferramenta de avaliação o Sistema Contábil Gerencial Ambiental (SICOGEA), considerando as etapas de preparação dos materiais, desde a geração do resíduo até sua disposição final. Para a implantação do sistema de gerenciamento foram aplicadas ferramentas de controle, elaboração de fluxo e capacitação dos funcionários, cujos métodos foram preparados em conjunto com os responsáveis pelas as áreas técnicas envolvidas e, por fim, após o explante ser considerado resíduo inservível é encaminhado a uma empresa especializada no tratamento dos resíduos de explantes para a manufatura reversa. Estudos futuros devem ser realizados para ampliar a análise para outros estabelecimentos de serviços de saúde, bem como realizar uma análise mais aprofundada da ecoeficiência do processo hospitalar. Com as medidas supracitadas implantadas, foi observado que houve um aumento de 45% para 100% da ecoeficiência nas operações relacionadas à destinação de resíduos de explantes, como resultado das melhorias implantadas no gerenciamento de descarte e encaminhamento para manufatura reversa.


  • IPEN-DOC 26458

    CARVALHO, LEANDRO G. de; PLAUT, RONALD L.; LIMA, NELSON B. de ; PADILHA, ANGELO F.. Kinetics of martensite reversion to austenite during overaging in a maraging 350 steel. ISIJ International, v. 59, n. 6, p. 1119-1127, 2019. DOI: 10.2355/isijinternational.ISIJINT-2018-610

    Abstract: The present work has studied the kinetics of partial reversion of martensite into austenite, which occurred during overaging between 520 and 600°C in a maraging 350 steel. The microstructural modifications were followed using optical microscopy, scanning electron microscopy, X-ray diffraction and ferritoscopy. The observations carried out using microscopy showed that the reverted austenite is formed at interface regions such as grain boundaries, boundaries of the packets and martensite laths boundaries of the martensitic structure starting at 520°C, while the reverted austenite observed inside the martensite lath was formed starting at 560°C. The maximum percentage volumetric fractions of retained austenite were 18%, 25% and 37%, respectively for 520, 560 and 600°C. The higher the aging temperature, the faster the volumetric fraction attained its plateau of maximum constant value. The activation energy for the kinetics of the austenite reversion process has been determined as being 332 kJ/mol. The Avrami constant for the kinetics of the reverted austenite at 520°C was close to 1, while at 560°C was close to 2. The values determined for the activation energy and of the Avrami constants have been discussed and correlated with the possible transformation mechanisms.


  • IPEN-DOC 26457

    PIRES, J.A. ; HARDER, M.N.C.; ARTHUR, V.; SILVA, L.C.A.S.. Ionizing radiation effects in Brazilian grape tree wine. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-14, 2019. DOI: 10.15392/bjrs.v7i2A.630

    Abstract: The aim of this work was to irradiate brazilian grape tree (Myrciaria cauliflora) wines with gamma radiation (Co60) to investigate the effect of radiation on its components and to create a new product with quality for the superior fermented beverages market. For this wine was produced in an artisan way, but with all the care of hygiene and sanitation. The brazilian grape tree was femented for five days and the wine was then filtered and stored in inert material containers then irradiated at 2.5 and 5 kGy doses. The samples were evaluated in relation to the radiation doses used. Physical and chemical analyzes of pH; total and volatile acidity; alcohol content; anthocyanins; tannins and colorimetry were performed. As a result, in most product analysis, had little effect on irradiation, except for anthocyanins and tannins. For this can be concluded that it is possible to develop a new fermented drink based on brazilian grape tree, according to the standards required by the legislation and that the irradiation at the dose of 5kGy was the sample that shown to have the most effect on the color because it was the one that degraded most molecules of anthocyanins and tannins.


  • IPEN-DOC 26456

    SILVA, HARYANE R.M.; FAUSTINO, WAGNER M.; TEOTONIO, ERCULES E.S.; BRITO, HERMI F.; MALTA, OSCAR L.; FELINTO, MARIA C.F.C. . Investigation on the formation of highly luminescent β-diketone-Ln(III)-EDTA water-soluble complexes. Journal of Luminescence, v. 207, p. 182-187, 2019. DOI: 10.1016/j.jlumin.2018.10.021

    Abstract: Three new β-diketone–Ln-EDTA (β-diketone=TTA, BTFA, ACAC; Ln=Eu3+ and Tb3+) water-soluble complexes were prepared, and their photophysical properties were investigated in aqueous solutions and compared with the Eu–EDTA complex. A very strong red and green luminescence was observed by the addition of ligands to the aqueous solutions of the Eu–EDTA and Tb–EDTA complexes, respectively, due to the formation of watersoluble β-diketone–Ln–EDTA complexes. To confirm the formation and stoichiometry of the new β- diketone–Ln–EDTA complex, the Judd–Ofelt intensity parameters Ω2 for Eu3+ complexes and the band width at half height (Δλ) for Tb3+ complexes were used. The dependence of these parameters on the addition of the β- diketone strongly suggests that only one β-diketonate ligand is in the first coordination sphere of the β- diketone–Ln–EDTA complexes. These new Eu3+ and Tb3+ systems may act as red and green optical markers for bioassay or bioimaging.


  • IPEN-DOC 26455

    FUJIMOTO, TALITA G. ; REIS, SHIRLEY L. ; MUCCILLO, ELIANA N. dos S. . Influence of yttria-stabilized zirconia on microstructure and electrical properties of doped lanthanum gallate. Materials Research, v. 22, S1, p. 1-6, 2019. DOI: 10.1590/1980-5373-MR-2019-0043

    Abstract: Lanthanum gallate with partial substitutions for strontium and magnesium shows higher ionic conductivity than traditional ionic conductors such as yttria-stabilized zirconia (8YSZ), and has been considered for application as solid electrolyte and electrode in Solid Oxide Fuel Cells operating at intermediate temperatures (500-700ºC). Parallel to the development of new solid electrolytes, improvement of the already known electrolytes has been one goal. In this work, the effects of adding 8YSZ to La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM), on the microstructure and electrical performance were investigated. Compound electrolytes consisting of up to 20 wt.% 8YSZ were prepared by solid state reactions. Sintered pellets with up to 10 wt.% 8YSZ achieved near full density after sintering at 1450ºC and reduction in the fraction of impurity phases. Addition of 8YSZ promoted grain growth to LSGM. The higher ionic conductivity was obtained for 1 wt.% 8YSZ addition with slight decrease of the apparent activation energy.


  • IPEN-DOC 26453

    SABINO, CAETANO P.; WAINWRIGHT, MARK; ANJOS, CAROLINA dos; SELLERA, FABIO P.; BAPTISTA, MAURICIO S.; LINCOPAN, NILTON; RIBEIRO, MARTHA S. . Inactivation kinetics and lethal dose analysis of antimicrobial blue light and photodynamic therapy. Photodiagnosis and Photodynamic Therapy, v. 28, p. 186-191, 2019. DOI: 10.1016/j.pdpdt.2019.08.022

    Abstract: Background: Antimicrobial Photodynamic therapy (A-PDT) has been used to treat infections. Currently, microbial inactivation data is reported presenting survival fraction averages and standard errors as discrete points instead of a continuous curve of inactivation kinetics. Standardization of this approach would allow clinical protocols to be introduced globally, instead of the piecemeal situation which currently applies. Methods: To this end, we used a power-law function to fit inactivation kinetics and directly report values of lethal doses (LD) and a tolerance factor (T) that informs if inactivation rate varies along the irradiation procedure. A deduced formula was also tested to predict LD for any given survival fraction value. We analyzed the photoantimicrobial effect caused by red light activation of methylene blue (MB-APDT) and by blue light (BL) activation of endogenous microbial pigments against 5 clinically relevant pathogens. Results: Following MB- APDT, Escherichia coli and Staphylococcus aureus cells become increasingly more tolerant to inactivation along the irradiation process (T < 1). Klebsiella pneumoniae presents opposite behavior, i.e., more inactivation is observed towards the end of the process (T > 1). P. aeruginosa and Candida albicans present constant inactivation rate (T˜1). In contrast, all bacterial species presented similar behavior during inactivation caused by BL, i.e., continuously becoming more sensitive to blue light exposure (T > 1). Conclusion: The power-law function successfully fit all experimental data. Our proposed method precisely predicted LD and T values. We expect that these analytical models may contribute to more standardized methods for comparisons of photodynamic inactivation efficiencies.


  • IPEN-DOC 26452

    GAROFALO, S.A.; SAKAE, L.O.; MACHADO, A.C.; CUNHA, S.R.; ZEZELL, D.M. ; SCARAMUCCI, T.; ARANHA, A.C.. In vitro effect of innovative desensitizing agents on dentin tubule occlusion and erosive wear. Operative Dentistry, v. 44, n. 2, p. 168-177, 2019. DOI: 10.2341/17-284-L

    Abstract: Purpose: The purpose of this study was to evaluate the effects of four in-office desensitizing products on dentin tubule occlusion and erosive wear. Methods: Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into five groups (n=11), according to treatment:No treatment - Control (C), Duraphat (DUR), Desensibilize Nano P (NP), ClinPro XT Varnish (XTV), and ClinPro White Varnish (CWV). They were then submitted to erosive/abrasive cycling for five days. After EDTA, treatment, and cycling, the specimens were analyzed with an environmental scanning electron microscope (ESEM) to verify the number of opened dentin tubules (ODT) which were counted by using ImageJ software, and with a profilometer to determine the surface curvature/loss. ESEM data were analyzed with two-way repeated measure analysis of variance and Tukey tests. For the profilometer, data were analyzed with Kruskal- Wallis, Tukey, and Mann-Whitney tests. Results: After treatment, all groups showed lower ODT than the control, without significant differences between them. After cycling, the only group that showed lower ODT than the control was group XTV; however, it did not significantly differ from the other groups. For the profilometric analysis, there were significant differences in SL between the experimental times after treatment and after cycling for all groups (p,0.05). After cycling, no surface loss was detected in groups DUR and XTV, which presented a significantly different curvature than group NP and the control group, but not from group CWV. Surface loss was detected for the control and groups NP and CWV, without difference among them. Conclusion: All desensitizing agents tested presented promising results concerning the obliteration of dentin tubules immediately after treatment. XTV was the only desensitizer capable of preventing the reopening of the tubules after the erosive/abrasive challenges. XTV and DUR presented a protective effect against dentin erosive wear.


  • IPEN-DOC 26449

    ARAUJO-SILVA, R.A. de; JORGE JUNIOR, A.M.; VEGA, L.E.R.; LEAL NETO, R.M. ; LEIVA, D.R.; BOTTA, W.J.. Hydrogen desorption/absorption properties of the extensively cold rolled β Ti-40Nb alloy. International Journal of Hydrogen Energy, v. 44, n. 36, p. 20133-20144, 2019. DOI: 10.1016/j.ijhydene.2019.05.211

    Abstract: β Ti-Nb BCC alloys are potential materials for hydrogen storage in the solid state. Since these alloys present exceptional formability, they can be processed by extensive cold rolling (ECR), which can improve hydrogen sorption properties. This work investigated the effects of ECR accomplished under an inert atmosphere on H2 sorption properties of the arc melted and rapidly solidified β Ti40Nb alloy. Samples were crushed in a rolling mill producing slightly deformed pieces within the millimeter range size, which were processed by ECR with 40 or 80 passes. Part of undeformed fragments was used for comparison purposes. All samples were characterized by scanning electron microscopy, x-ray diffractometry, energy-dispersive spectroscopy, hydrogen volumetry, and differential scanning calorimetry. After ECR, samples deformed with 40 passes were formed by thick sheets, while several thin layers composed the specimens after 80 passages. Furthermore, deformation of β Ti-40Nb alloys synthesized samples containing a high density of crystalline defects, cracks, and stored strain energy that increased with the deformation amount and proportionally helped to overcome the diffusion's control mechanisms, thus improving kinetic behaviors at low temperature. Such an improvement was also correlated to the synergetic effect of resulting features after deformation and thickness of stacked layers in the different deformation conditions. At the room temperature, samples deformed with 80 passes absorbed ~2.0 wt% of H2 after 15 min, while samples deformed with 40 passes absorbed ~1.8 wt% during 2 h, excellent results if compared with undeformed samples hydrogenated at 300 C that acquired a capacity of ~1.7 wt% after 2 h. The hydrogen desorption evolved in the same way as for absorption regarding the deformation amount, which also influenced desorption temperatures that were reduced from ~270 C, observed for the undeformed and samples deformed with 40 passes, to ~220 C, for specimens rolled with 80 passes. No significant loss in hydrogen capacity was observed in the cold rolled samples.


  • IPEN-DOC 26447

    SILVA, ANDERSON F.V. da; FAGUNDES, ANA P.; MACUVELE, DOMINGOS L.P.; CARVALHO, ELITA F.U. de ; DURAZZO, MICHELANGELO ; PADOIN, NATAN; SOARES, CINTIA; RIELLA, HUMBERTO G.. Green synthesis of zirconia nanoparticles based on Euclea natalensis plant extract: optimization of reaction conditions and evaluation of adsorptive properties. Colloids and Surfaces A, v. 583, p. 1-10, 2019. DOI: 10.1016/j.colsurfa.2019.123915

    Abstract: The development of nanomaterials has attracted increasing attention recently. The study of new technologies to obtain these materials becomes extremely important since the majority of the nanomaterials synthesized require reagents and solvents. These reagents and solvents are sometimes toxic and may generate harmful residues to the environment and the health of living beings. Therefore, green synthesis is a potential alternative to obtain nanoparticles, sustainably, using ecological sources. This study developed a method of synthesizing the green of zirconia (ZrO2) nanoparticles using Euclea natalensis (Natal gwarri or Natal ebony tree with African origin) plant extract. Moreover, the adsorptive properties against tetracycline were evaluated. A factorial design was applied in the synthesis process, and an optimization of the reaction parameters (plant extract concentration, precursor concentration, and calcination temperature) was also described for the first time in literature. The nanoparticles were characterized using the XRD, FTIR and TEM techniques, and then subjected to batch adsorption tests. The samples presented the zirconia monoclinic and tetragonal phases, according to the XRD analysis, yielding materials with minimum crystallite sizes equal to 5.25 nm. The FTIR spectra confirmed the results obtained by the XRD, presenting band characteristic of the zirconia monoclinic and tetragonal phases. The particles had a rounded morphology with a very low average diameter ranging from 5.90 to 8.54 nm. Moreover, the nanoparticles were applied to the adsorption of tetracycline. The samples were synthesized with vegetal extract and precursor concentration equal to 50 g L−1 and 0.03 mol L−1, respectively, and calcination temperature of 550 °C, presented in the best performance (loading of 30.45 mg g−1). The adsorption capacity of the zirconia synthesized in this study was significantly higher than other common materials applied to tetracycline removal. The green synthesis procedure, as well as the application of the zirconia nanoparticles to the adsorption of an emerging pollutant, were promising.


  • IPEN-DOC 26446

    AMARAL, MARCELLO M. ; ZEZELL, DENISE M. ; MONTE, ADAMO F.G.; CARA, ANA C.B. de ; ARAUJO, JEANN C.R.; ANTUNES, ANDREA; FREITAS, ANDERSON Z. . General model for depth-resolved estimation of the optical attenuation coefficients in optical coherence tomography. Journal of Biophotonics, v. 12, n. 10, p. 1-13, 2019. DOI: 10.1002/jbio.201800402

    Abstract: We present the proof of concept of a general model that uses the tissue sample transmittance as input to estimate the depth-resolved attenuation coefficient of tissue samples using optical coherence tomography (OCT). This method allows us to obtain an image of tissue optical properties instead of intensity contrast, guiding diagnosis and tissues differentiation, extending its application from thick to thin samples. The performance of our method was simulated and tested with the assistance of a home built single-layered and multilayered phantoms (~100 μm each layer) with known attenuation coefficient on the range of 0.9 to 2.32 mm−1. It is shown that the estimated depth-resolved attenuation coefficient recovers the reference values, measured by using an integrating sphere followed by the inverse adding doubling processing technique. That was corroborated for all situations when the correct transmittance value is used with an average difference of 7%. Finally, we applied the proposed method to estimate the depth-resolved attenuation coefficient for a thin biological sample, demonstrating the ability of our method on real OCT images.


  • IPEN-DOC 26445

    LEMOS, F.S.; PEREIRA, J.X.; CARVALHO, V.F.; BERNARDES, E.S. ; CHAMMAS, R.; PEREIRA, T.M.; CARVALHO, R.S.; LUISETTO, R.; EL-CHEIKH, M.C.; CALIL-ELIAS, S.; OLIVEIRA, F.L.. Galectin-3 orchestrates the histology of mesentery and protects liver during lupus-like syndrome induced by pristane. Scientific Reports, v. 9, 2019. DOI: 10.1038/s41598-019-50564-8

    Abstract: Galectin-3 (Gal-3) controls intercellular and cell-extracellular matrix interactions during immunological responses. In chronic inflammation, Gal-3 is associated with fibrotic events, regulates B cell differentiation and delays lupus progression. Gal-3 deficient mice (Lgals3−/−) have intense germinal center formation and atypical plasma cell generation correlated to high levels IgG, IgE, and IgA. Here, we used pristane (2,6,10,14-tetramethylpentadecane) to induce lupus-like syndrome in Lgals3−/− and Lgals3+/+ BALB/c mice. Mesentery and peritoneal cells were monitored because promptly react to pristane injected in the peritoneal cavity. For the first time, mesenteric tissues have been associated to the pathogenesis of experimental lupus-like syndrome. In Lgals3+/+ pristane-induced mice, mesentery was hallmarked by intense fibrogranulomatous reaction restricted to submesothelial regions and organized niches containing macrophages and B lymphocytes and plasma cells. In contrast, Lgals3−/− pristane-treated mice had diffuse mesenteric fibrosis affecting submesothelium and peripheral tissues, atypical M1/M2 macrophage polarization and significant DLL1+ cells expansion, suggesting possible involvement of Notch/Delta pathways in the disease. Early inflammatory reaction to pristane was characterized by significant disturbances on monocyte recruitment, macrophage differentiation and dendritic cell (DC) responses in the peritoneal cavity of pristane-induced Lgals3−/− mice. A correlative analysis showed that mesenteric damages in the absence of Gal-3 were directly associated with severe portal inflammation and hepatitis. In conclusion, it has suggested that Gal-3 orchestrates histological organization in the mesentery and prevents lupoid hepatitis in experimental lupus-like syndrome by controlling macrophage polarization, Notch signaling pathways and DC differentiation in mesenteric structures.


  • IPEN-DOC 26444

    YORIYAZ, HELIO ; BRANCO, ISABELA S.L. ; ALMEIDA, ISABEL P.; FONSECA, GABRIEL P.. Fundamentos de transporte e cálculo de dose em tratamentos com feixes de prótons / Fundamentals of transport and dose calculation in proton beam therapy. Revista Brasileira de Física Médica, v. 13, n. 1, p. 109-115, 2019. DOI: 10.29384/rbfm.2019.v13.n1.p109-115

    Abstract: Este artigo de revisão apresenta um breve histórico, com os principais fatos da evolução da terapia com feixe de prótons, seguido de uma descrição das principais características dosimétricas apresentadas em faixas de energia utilizadas em terapia. É feita uma breve comparação entre a protonterapia e as demais modalidades de radioterapia com feixe de fótons. Também estão descritos alguns códigos de Monte Carlo atualmente utilizados na simulação do transporte de prótons no meio e suas peculiaridades.


  • IPEN-DOC 26443

    SILVA, FELIPE D. ; OLIVEIRA, JOÃO E. ; FREIRE, RENAN P. ; SUZUKI, MIRIAM F. ; SOARES, CARLOS R. ; BARTOLINI, PAOLO . Expression of glycosylated human prolactin in HEK293 cells and related N‑glycan composition analysis. AMB Express, v. 9, n. 1, p. 1-11, 2019. DOI: 10.1186/s13568-019-0856-8

    Abstract: Prolactin (PRL) is a hormone produced by the pituitary gland with innumerable functions, such as lactation, reproduction, osmotic and immune regulation. The present work describes the synthesis of hPRL in human embryonic kidney (HEK293) cells, transiently transfected with the pcDNA-3.4-TOPO® vector carrying the hPRL cDNA. A concentration of ~ 20 mg/L, including glycosylated (G-hPRL) and non-glycosylated (NG-hPRL) human prolactin, was obtained, with ~ 19% of G-hPRL, which is higher than that observed in CHO-derived hPRL (~ 10%) and falling within the wide range of 5–30% reported for pituitary-derived hPRL. N-Glycoprofiling analysis of G-hPRL provided: (i) identification of each N-glycan structure and relative intensity; (ii) average N-glycan mass; (iii) molecular mass of the whole glycoprotein and relative carbohydrate mass fraction; (iv) mass fraction of each monosaccharide. The data obtained were compared to pituitary- and CHO-derived G-hPRL. The whole MM of HEK-derived G-hPRL, determined via MALDI–TOF-MS, was 25,123 Da, which is 0.88% higher than pit- and 0.61% higher than CHO-derived G-hPRL. The main difference with the latter was due to sialylation, which was ~ sevenfold lower, but slightly higher than that observed in native G-hPRL. The “in vitro” bioactivity of HEK-G-hPRL was ~ fourfold lower than that of native G-hPRL, with which it had in common also the number of N-glycan structures.


  • IPEN-DOC 26442

    SANTOS, O.C.B.; VANIN, V.R.; MAIDANA, N.L.; MARTINS, M.N.; TABACNIKS, M.H.; RODRIGUES, C.L.; SILVA, T.F.; SANTOS, A.D.; BARROS, S.F.; GARCIA-ALVAREZ, J.A.; KOSKINAS, M.F. ; FERNANDEZ-VAREA, J.M.; PINDZOLA, M.S.. Experimental and theoretical cross sections for K-shell ionization of 52Te, 73Ta, and 83Bi by electrons with energies up to 100 keV. Physical Review A, v. 100, n. 2, p. 022703-1 - 022703-9, 2019. DOI: 10.1103/PhysRevA.100.022703

    Abstract: In this work we present a combined experimental and theoretical study of K-shell ionization by electrons with energies close to the threshold. The ionization cross sections of the K shells of Te, Ta, and Bi atoms have been measured up to 100 keV with uncertainties ranging from 4% to 8%. In turn, calculations have been done using the subconfiguration average distorted-wave (SCADW) method, which includes the full two-body retarded electromagnetic interaction between the projectile and target electrons. The predictions of the SCADW method are in good agreement with the experimental data. In contrast, theoretical cross sections based on first-order perturbation theory where the transverse interaction is computed with plane waves instead of distorted waves underestimate the SCADW values as well as the experimental data. The difference between the two investigated ab initio formalisms grows with atomic number, being 3% for Te, 15% for Ta, and 25% for Bi. An additional comparison of both theoretical approaches with recent measurements for Au K supports the conclusion that the SCADW method reproduces well the experimental K-shell ionization cross section of atoms with intermediate to large Z near the threshold.


  • IPEN-DOC 23190

    QUINTO JUNIOR, JOSE ; AMARAL, MARCELLO M. ; FRANCCI, CARLOS E.; ANA, PATRICIA A. ; MORITZ, ANDREAS; ZEZELL, DENISE M. . Evaluation of intra root canal Er,Cr:YSGG laser irradiation on prosthetic post adherence. Journal of Prosthodontics, v. 28, n. 1, p. e181-e185, 2019. DOI: 10.1111/jopr.12609

    Abstract: Purpose: In clinical prosthetics procedures, including endodontics and post fixation, the presence of a smear layer can reduce the post bond strength. An Er,Cr:YSGG laser, which emits at 2780 nm, can promote a smear-layer-free surface due to the ablation process. Considering these aspects, the purpose of this work was to evaluate the influence of Er,Cr:YSGG laser irradiation using either a radial or an axial fiber tip on the bond strength of three resin cements to the fiber-reinforced composite posts. Materials and Methods: Ninety recently extracted single rooted human teeth had their root canal instrumented and were randomly distributed into nine experimental groups, in which three resin cements (total-etching Variolink II, self-etching Panavia F, and self-adhesive RelyX Unicem Aplicap) and three root canal treatments (no treatment, laser irradiation using the radial fiber tip, laser irradiation using the axial fiber tip) were used. Specimens were then sectioned into three sections (cervical, middle, and apical thirds) with two slices on each section. A push-out test was performed on each slice, and the values were recorded as MPa. The push-out data were analyzed by a Ryan-Joiner normality test followed by a two-way ANOVA test and Tukey pairwise comparison. The statistical analysis was performed on each third section separately, with a 5% significance level. Results: Laser irradiation with axial fiber tip significantly increased the post bond strength of RelyX Unicem Aplicap on middle third of specimens (p < 0.001) when compared to other root canal treatments (unlased or irradiated with radial tip). Considering the Panavia resin cement, laser irradiation with either axial or radial tips promoted a significant increase on the post bond strength of middle third when compared to unlased specimens (p < 0.001); however, laser irradiation did not influence the post bond strength of Variolink resin cement. Conclusions: The use of the Er,Cr:YSGG laser for clinical prosthetics procedures enhances the post bond strength of Panavia and RelyX Unicem Aplicap resin cements, mainly at middle third of roots, and does not interfere with the bond strength of Variolink resin cement. For the RelyX Unicem Aplicap system, the use of axial tip is most advantageous and can be recommended for future clinical application.


  • IPEN-DOC 26440

    SOUZA, ARMANDO C. de; CIONE, FRANCISCO C. ; SILVA, ALINE C. da; GOUVEA, ADRIANA de F.G.; MACHADO, NOE G.P. ; RAELE, MARCUS P. ; ROSSI, JESUALDO L. . Evaluation of a metal-organic composite (tungsten-lignin) for attenuation of gamma radiation. Materials Research, v. 22, S1, p. 1-5, 2019. DOI: 10.1590/1980-5373-MR-2019-0045

    Abstract: The objective of this work was to use tungsten and lignin as precursors to obtain a metal-organic composite tungsten-lignin (W-Lig) using different sintering temperatures. Tungsten is a refractory metal and it was selected for the composite since it is widely used for high-energy radiation shielding as it has an excellent absorption cross section for thermal neutrons. Lignin extracted from lignocelluloses biomass and it was selected to be the organic precursor for the composite due to its multiple applications. Analysis of the composite was performed after sintering processes, using a 3D optical surface profiler and measurement of the gamma radiation attenuation coefficient using cobalt source (Co-60). Metalorganic composites in ratios of W2.5%Lig and W5%Lig (in mass % of lignin) were used. The gradient of the attenuation coefficient differed when standard tungsten and the composites of W2.5%Lig and W5%Lig were compared. Therefore, the attenuation coefficient between unobstructed free radiation and the W5%Lig 90 ºC composite showed a gradient of about 43% in the two characteristic Co-60 energy peaks, with a sample thickness of 0.679 cm the calculated linear attenuation coefficient was 0.832 cm-1.


  • IPEN-DOC 26439

    GARDA, GIANNA M.; FILGUEIRA, DIEGO A.; PUGLIESI, REYNALDO ; PEREIRA, MARCO A.S. ; SAYEG, ISAAC J.. Estudo da mineralização de cobre em basaltos do Grupo Serra Geral, utilizando difratometria de raios X, microscopia eletrônica de varredura-espectroscopia por energia dispersiva e tomografia com nêutrons / Study of copper mineralization in basalts of the Serra Geral Group, using X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, and neutron tomography. Geologia USP - Série Científica, v. 19, n. 3, p. 111-127, 2019. DOI: 10.11606/issn.2316-9095.v19-152501

    Abstract: Mineralizações de cobre do tipo Michigan ocorrem nos derrames basálticos do Grupo Serra Geral na região de Nova Prata do Iguaçu, sudoeste do estado do Paraná. Nessas mineralizações, o cobre nativo é o principal mineral de minério e, com a alteração supérgena, transforma-se em óxidos de cobre, malaquita e crisocola, sendo esta encontrada na forma de um precipitado gelatinoso que preenche amígdalas e impregna fraturas no basalto, além de recobrir minerais secundários e outros produtos de alteração. Neste estudo, foram utilizadas as técnicas de difratometria de raios X e microscopia eletrônica de varredura-espectroscopia por energia dispersiva (MEV-EDS) para a caracterização do grau de cristalinidade e composição química da crisocola e a identificação de outros materiais hidrogenados, como subsídio para o imageamento 3D por tomografia com nêutrons. A crisocola destacou-se como um eficiente atenuador de nêutrons, obtendo-se coeficiente de atenuação linear da ordem de 0,8–1,3 cm-1, ao passo que, para o corpo de minério (basalto), obteve-se 0,5–0,6 cm-1. O contraste entre os coeficientes permitiu a obtenção de imagens tomográficas e filmes de boa resolução, em que se pôde visualizar a distribuição da crisocola na amostra de basalto e estimar como fração volumétrica de crisocola no corpo de minério valores entre 0,9 e 1,4%, obtendo-se o valor de 7,8% em volume de crisocola para uma das amostras. A utilização integrada das três técnicas analíticas demonstrou que esta pode ser uma ferramenta para avaliação do potencial mineral nas fases iniciais da prospecção mineral, especialmente quando as substâncias de interesse são ricas em hidrogênio.


  • IPEN-DOC 26438

    MEDINA, MIDILANE S. ; CARVALHO, SABRINA G.M. ; MUCCILLO, ELIANA N.S. ; MUCCILLO, REGINALDO . Enhancement of the ionic conductivity in electric field-assisted pressureless sintered BITIVOX solid electrolytes. Ceramics, v. 2, n. 3, p. 502-513, 2019. DOI: 10.3390/ceramics2030038

    Abstract: Bi4V1.8Ti0.2O11 (BITIVOX) ceramic pellets, prepared with powders obtained by a sol gel technique, were sintered either conventionally at 800 C/8 h or by applying an AC electric voltage, limiting the electric current through the pellets. Electric voltages were applied isothermally at 700 C and 800 C during 5 min in the green pellet positioned in the sample holder of a dilatometer for monitoring thickness variation. The BITIVOX pellets shrank 13.6% after applying 200 V cm􀀀1 at 800 C and 10.4% heating to 800 C for 8 h. Thermal analysis and X-ray di raction of the powders were performed to evaluate the crystallization temperature and the structural phase, respectively. The electrical behavior of the sintered BITIVOX pellets was analyzed by the impedance spectroscopy technique, showing that the sample flash sintered at 800 C/5 min had lower bulk resistivity than the sample conventionally sintered at 800 C/8 h. The surfaces of the sintered pellets were observed in a scanning electron microscope showing similar grain sizes and pore content in all sintered samples.


  • IPEN-DOC 26437

    REIS, SHIRLEY L. ; CARVALHO, SABRINA G.M. ; MUCCILLO, ELIANA N.S. ; MUCCILLO, REGINALDO . Electrical behavior of electric field-assisted pressureless sintered ceria-20 mol% samaria. Ceramics, v. 2, n. 2, p. 385-392, 2019. DOI: 10.3390/ceramics2020030

    Abstract: CeO2:20 mol% Sm2O3 green ceramic pellets were sintered conventionally at 1500 C/2 h and flash sintered by applying a 200 V cm􀀀1 electric field at 800 C, 1000 C and 1200 C. The thickness shrinkage of the pellets was followed bythe specimen being positioned inside a dilatometer adapted with platinum electrodes and terminal leads connected to a power supply for application of the electric voltage. The microstructure of the surfaces of the sintered samples were observed in a scanning electron microscope. The electrical properties were evaluated by the impedance spectroscopy technique in the 5 Hz–13 MHz frequency range from 210 C to 280 C. The main results show that (i) the final shrinkage level is nearly independent of the temperature when the electric field is applied and slightly better than that of the 1500 C sintered pellet, and (ii) the bulk conductivity of the sample flash sintered at 1200 C is similar to that of the sample sintered at 1500 C. The availability of a pathway for the electric current pulse derived from the applied electric field is proposed as the reason for the achieved shrinkages. Scavenging of the grain boundaries by Joule heating is proposed as the reason for the improved oxide ion bulk conductivity.


  • IPEN-DOC 26436

    BETINI, EVANDRO G. ; GOMES, MAURILIO P. ; MUCSI, CRISTIANO S. ; ORLANDO, MARCOS T.D.; LUZ, TEMISTOCLES de S.; AVETTAND-FENOEL, MARIE-NOELLE; ROSSI, JESUALDO L. . Effect of nitrogen addition to shielding gas on cooling rates and in the microstructure of thin sheets of duplex stainless steel welded by pulsed gas tungsten arc welding process. Materials Research, v. 22, 1, p. 1-9, 2019. DOI: 10.1590/1980-5373-MR-2019-0247

    Abstract: The effect of the nitrogen content in the shielding gas and its effect on temperature distributions at the welded zone of thin sheets of duplex stainless steel have been evaluated. The duplex stainless steels have many features due to unique microstructural combination of austenite and ferrite grains. The phase balance can be easily shifted depending on the welding parameters. Two sheets were welded using pure argon and pure argon plus 2% of nitrogen as shielding gas. The thermal profile had shown that N2-supplemented shielding gas lead to higher peaks of temperature using similar welding parameters. Microstructural examination showed that the austenite phase in the weld increased with the presence of nitrogen in the shielding gas. The added nitrogen promoted primary austenite formation and slightly increases the microhardness at the solidified zone. Microhardness mapping and metallographic imaging presented information about microstructures, confirming the formation of secondary phases during thermal cycle in the temperature range 850 °C and 950 °C. Control of ferrite amounts in the welds is essential mainly to improve mechanical properties and corrosion resistance of welding zones.


  • IPEN-DOC 26435

    SALGADO, MARIA de F.; CARVALHO, IURE S.; SANTOS, RAFAEL S.; PORTO, JOÃO A.S.; CORREA, OLANDIR V. ; RAMANATHAN, LALGUDI V. ; BRANDIM, AYRTON de S.; LINS, VANESSA F.C.. Effect of oxygen partial pressure on oxidation behavior of ferritic stainless steel AISI 441 at high temperatures. Engineering Failure Analysis, v. 105, p. 215-226, 2019. DOI: 10.1016/j.engfailanal.2019.07.011

    Abstract: In this investigation the oxidation behavior of AISI 441 stainless steel (SS) in the range from 850 °C to 950 °C was determined during 50 h in two different atmospheres: (a) synthetic air in a tubular oven; (b) argon with 1 ppm of O2 in a thermal balance. The oxidation kinetics was determined from the measured mass change as a function of oxidation time. Examination of the microstructure of the oxides and determination of their chemical composition were performed by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and glancing angle X-ray diffraction (GAXRD). Chemical analyses showed that films formed on the AISI 441 steel surface consisted mostly of chromium oxide but manganese, iron, titanium and silicon oxides were found in the oxidized layer. In synthetic air, the steel oxidation rate increased gradually as the temperature increased, but in the argon atmosphere with 1 ppm of oxygen, the highest oxidation rate was observed at 900 °C and the lowest at 950 °C.


  • IPEN-DOC 26431

    SILVA, DIEGO S. da ; WETTER, NIKLAUS U. ; KASSAB, LUCIANA R.P.; ROSSI, WAGNER de ; ARAUJO, MARIANA S. de . Double line waveguide amplifiers written by femtosecond laser irradiation in rare-earth doped germanate glasses. Journal of Luminescence, v. 217, p. 1-5, 2020. DOI: 10.1016/j.jlumin.2019.116789

    Abstract: We report the production of active double waveguides in Er/Yb doped GeO2-PbO glasses, by direct femtosecond laser writing. The glasses were produced using the melt-quenching technique and the active waveguides were written using 30 fs laser pulses, at 800 nm, with writing speed of 0.06 mm/s and pulse energy of 32 μJ. The photo-induced negative refractive index change was of 􀀀 7.4 � 10􀀀 3. The Er/Yb doped sample showed a relative gain (signal enhancement of 7.5 dB/cm, for 105 mW of 980 nm pump power. The relative gain compensates both, the propagation losses and the absorption losses, and a positive maximum internal gain of 4.6 dB/cm can be obtained at the signal wavelength of 1550 nm. The results obtained in present work demonstrate that Er/Yb glasses are promising materials for the fabrication of integrated amplifiers, lossless components and lasers based on germanate glasses.

    Palavras-Chave: laser spectroscopy; optical systems; amorphous state; rare earths; germanates; doped materials; glass; laser radiation; waveguides


  • IPEN-DOC 26430

    PEREIRA, MARCO A.M.; SILVEIRA, LUCAS M.; NANNINI, FELIX; NEVES, LUCIO P.; PERINI, ANA P.; SANTOS, CARLA J.; BELINATO, WALMIR; SANTOS, WILLIAM S. . Dosimetric evaluation of individuals to 238U series, 232Th series and 40K radionuclides present in Brazilian ornamental rocks using computational simulation. Ecotoxicology and Environmental Safety, v. 173, p. 401-410, 2019. DOI: 10.1016/j.ecoenv.2019.02.038

    Abstract: Granites are widely used in construction and they may be potential sources of ionizing radiation, due to the presence of radionuclides such as 40K and decay products from 238U series and 232Th series. These radionuclides occur in the minerals constituting the rocks. To evaluate the doses in humans exposed to 40K, and decay products from 238U series and 232Th series radiation, a room with dimensions of 4.0 × 5.0 × 2.8m3, with uniformly distributed radiation source on the floor of granitic rocks, was computationally modeled. Adult individuals were represented in the virtual scenario by two virtual anthropomorphic phantoms FASH3 and MASH3, incorporated simultaneously in the software MCNPX 2.7.0. The mean energy deposited on each organ and tissue of FASH3 and MASH3 phantoms was determined using the MCNPX F6 tally (MeV/g/particle), while the photon flux within the room was calculated with the MCNPX F4 tally (MeV/cm2/particle). The organs that obtained the highest conversion coefficients CC[HT] (Sv/Gy) were the red bone marrow (0.94), skin (0.90), breast (0.81) and bladder (0.73) for the FASH3; skin (0.89), gonads (0.88), breast (0.79) and bladder (0.70) for the MASH3. The simulated air absorbed dose rates varied between 23.4 (11%) and 25.8 (12%) nGy/h, and the annual dose rates were 0.10 (6%) and 0.11 (6%) mSv/year. These results presented acceptable statistical uncertainties and they are in agreement with the literature. Fluency of photons pointed to the central region of the room floor as the place of greatest exposure. The results showed that the organs closer to the radiation source had the highest deposited energy values. Based on the annual effective dose data obtained, it was possible to note that the values are within the literature. We believe that the methodology used will allow the investigation of any ornamental material that emits natural radiation.


  • IPEN-DOC 26429

    SANTOS, MONIQUE C.L. ; NUNES, LIVIA C.; SILVA, LUIS M.G. ; RAMOS, ANDREZZA S.; FONSECA, FABIO C. ; SOUZA, RODRIGO F.B. de ; NETO, ALMIR O. . Direct alkaline anion exchange membrane fuel cell to converting methane into methanol. ChemistrySelect, v. 4, n. 39, p. 11430-11434, 2019. DOI: 10.1002/slct.201902421

    Abstract: Methane is the main constituent of natural gas and can be converted in higher value-added products for electricity cogeneration. It could be used as a solid membrane reactor (SMR) for application in Alkaline Anion-Exchange Membrane Fuel Cell (AAEMFC). The investigation for the conversion of methane was based on sodium borohydride (NaBH4) method using Pt/C Basf, Pd/C, Ni/C as catalysts. The electrocatalysts were prepared with 20 wt% of metals loading on carbon. The X-ray diffraction (XRD) analysis revealed a face-centered cubic structure (FCC) for Pt/C and Pd/C catalysts, was observed Ni/ NiO phases for Ni/C electrocatalyst. The Transmission Electron Microscopy (TEM) exhibited a good dispersion of nanoparticles and some agglomerations on the support, with a mean size of 6.4 nm for Pd/C, 5.7 nm for Ni/C and near to 2 nm size for Pt/C. The experiments with AAEMFC showed that all materials can carry out the reaction spontaneously. Pt/C catalyst presents energy density higher than the other materials. FTIR data suggest that methane was converted into small products organic molecules such as methanol and formate in different potentials for Pt/C, Pd/C, and Ni/C. The products were quantified by Raman spectroscopy. The high conversion efficiency obtained was about 20% at 0.3 V using Pt/C catalyst, the maximum conversion over Pd/C was 17.5% at 0.15 V, associated with the formation of a thin layer of PdO on the catalytic surface. The highest conversion rate (13%) was observed in closed circuit potentials to the short circuit in the cell with Ni/C catalyst. The results suggest that for the selective conversion of methane to methanol are most promising using materials containing Pt or Pd.

    Palavras-Chave: methane; fuel cells; methanol; spectroscopy; electrocatalysts; catalysts; natural gas; raman spectroscopy; transmission electron microscopy


  • IPEN-DOC 26428

    KAISER, THIAGO J.S.; SEMMLER, RENATO ; LIMA, GEAN B. de. Development of a web free software for the absolute efficiency calibration for HPGe type detectors. International Journal of Advanced Engineering Research and Science, v. 6, n. 5, p. 318-327, 2019. DOI: 10.22161/ijaers.6.5.42

    Abstract: The IEA-R1, swimming pool research reactor, from the Institute of Energy and Nuclear Research (IPEN), among other uses, the instrumental neutron activation analysis technique is widely used, and successfully, by the Neutron Activation Laboratory (LAN), using the comparative method. In this method a sample is irradiated simultaneously with a standard. In order to overcome the difficulty of a multi -elementary analysis, because it was necessary to prepare several standards, the k0 method of neutron activation was developed. In method k, the concentration of sample elements is calculated in relation to a comparator element, generally gold. However, for the use of the k0 method, it is necessary to accurately determine the detection efficiency in the energy range of interest and the geometry of the experimental arrangement. In order to circumvent the manual processing of the data in spreadsheets, which could be affected by errors, a free code web software was developed for calibration in absolute efficiency of an HPGe type detector for neutron activation analysis based on the k0. We used the free, low learning curve standardized Python programming language in the eScience project, which is part of the software, and the Django web framework with a simple and intuitive interface. In the system it is possible to register the detectors, radioactive sources and their manufacturers, projects and spectra, attributes necessary to calculate the absolute efficiency of an HPGe type detector. In addition to calculating efficiency, the system plots the graph with the efficiency points, trend curve, with possibility of adjustments, and error bar representing the uncertainties. The system issues reports on spectra and efficiency data for each project. The reports make it possible to check the data as well as its use in other applications. Because it is a web software, its access is allowed from any device with an internet connection. Another result obtained with the system is the reduction of the possibility of errors with the manual treatment of the data in spreadsheets.


  • IPEN-DOC 26427

    FRANCISCO, L.H.C. ; FELINTO, M.C.F.C. ; BRITO, H.F.; TEOTONIO, E.E.S.; MALTA, O.L.. Development of highly luminescent PMMA films doped with Eu3+β‑diketonate coordinated on ancillary ligand. Journal of Materials Science: Materials in Electronics, v. 30, n. 18, SI, p. 16922-16931, 2019. DOI: 10.1007/s10854-019-01639-9

    Abstract: In this work, [Eu(tta)3(4-picNO)2] and [Eu(dbm)3(4-picNO)] complexes were incorporated on different concentrations (x = 1, 3, 5, 10 and 15%) in PMMA polymeric matrix (4-picNO: 4-Methylpyridine N-oxide) by the solvent casting method, yielding transparent and highly luminescent polymeric films. These materials were analyzed by X-ray diffraction, scanning electron microscopy and by energy dispersive, ultraviolet–visible spectroscopy, luminescence and vacuum ultraviolet–ultraviolet spectroscopies. The luminescence spectra of doped PMMA films are in agreement with an efficient intramolecular diketonate (tta) ligand-to-europium energy transfer. Furthermore, the values of experimental intensity parameters (Ω2,4) for luminescent polymeric materials were quite similar to those ones for isolated complexes, indicating that there is a homogeneous dispersion of Eu3+ complexes in the polymeric matrix, preserving their chemical and structural features. These behavior were also observed from the CIE diagram that show great similarity between the (x,y) coordinates for the doped PMMA samples compared to the isolated β-diketonate complexes with a reddish color tuning. The photostability investigation of the doped PMMA polymeric films and Eu3+ complexes has been also reported.


  • IPEN-DOC 26426

    BARROS, L.F. ; RIBEIRO, R.V. ; DIAS, M.S. ; MORALLES, M. ; SEMMLER, R. ; YAMAZAKI, I.M. ; KOSKINAS, M.F. . Determination of k0 and Q0 for 74Se, 113In, 186W and 191Ir targets applying covariance analysis. Applied Radiation and Isotopes, v. 154, p. 1-7, 2019. DOI: 10.1016/j.apradiso.2019.108846

    Abstract: In the present work, the determinations of k0 and Q0 for 74Se, 113In, 186W and 191Ir targets were performed. The irradiations were conducted near the core of the IEA-R1 4.5MW swimming-pool nuclear research reactor of the Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP – Nuclear and Energy Research Institute), in São Paulo, Brazil. The irradiation position was chosen where the neutron spectrum shape parameter α is very close to zero. For this reason, the correction to be applied for the determination of Q0 is very close to one, thus improving the accuracy of the results. For each experiment, two irradiations were carried out in sequence: the first one with bare samples and the second with a cadmium cover around the samples. All partial uncertainties were considered, applying the covariance matrix methodology. The final results were compared with the literature.


  • IPEN-DOC 26425

    ALVARENGA, TALLYSON S. ; FREITAS, BRUNO M.; FONSECA, EVALDO S.; PEREIRA, WALSAN W.; CALDAS, LINDA V.E. . Determination of the scattered radiation at the neutron calibration laboratory of IPEN using the Shadow Cone method. Brazilian Journal of Radiation Sciences, v. 7, n. 2B, p. 1-9, 2019. DOI: 10.15392/bjrs.v7i2B.386

    Abstract: Because of the increase in the demand for the calibration of neutron detectors, there is a need for new calibration services. In this context, the Calibration Laboratory of Instituto de Pesquisas Energéticas e Nucleares (IPEN), São Pau-lo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new test laboratory for neutron detectors. This work evaluated the contribution of dispersed neutron radiation in this laboratory, using the Cone Shadow Method and a Bonner Sphere Spectrometer to take the measure-ments at a distance of 100 cm from the neutron source. The dosimetric quantities Ambient Dose Equivalent Rate (Ḣ*(10)) and Ambient Dose Equivalent Conversion Coefficient (h*(10)) were obtained at the laboratory, allowing the calibration of detectors.

    Palavras-Chave: americium 241; bonner sphere spectrometers; brazilian cnen; calibration; neutron detectors; neutron sources; radiation scattering analysis; shadow effect


  • IPEN-DOC 26424

    BERBEL, LARISSA O. ; BANCZEK, EVERSON do P.; KAROUSIS, IOANNIS K.; KOTSAKIS, GEORGIOS A.; COSTA, ISOLDA . Determinants of corrosion resistance of Ti-6Al-4V alloy dental implants in an In Vitro model of peri-implant inflammation. PLoS ONE, v. 14, n. 1, p. 1-17, 2019. DOI: 10.1371/journal.pone.0210530

    Abstract: Background Titanium (Ti) and its alloys possess high biocompatibility and corrosion resistance due to Ti ability to form a passive oxide film, i.e. TiO2, immediately after contact with oxygen. This passive layer is considered stable during function in the oral cavity, however, emerging information associate inflammatory peri-implantitis to vast increases in Ti corrosion products around diseased implants as compared to healthy ones. Thus, it is imperative to identify which factors in the peri-implant micro-environment may reduce Ti corrosion resistance. Methods The aim of this work is to simulate peri-implant inflammatory conditions in vitro to determine which factors affect corrosion susceptibility of Ti-6Al-4V dental implants. The effects of hydrogen peroxide (surrogate for reactive oxygen species, ROS, found during inflammation), albumin (a protein typical of physiological fluids), deaeration (to simulate reduced pO2 conditions during inflammation), in an acidic environment (pH 3), which is typical of inflammation condition, were investigated. Corrosion resistance of Ti-6Al-4V clinically-relevant acid etched surfaces was investigated by electrochemical techniques: Open Circuit Potential; Electrochemical Impedance Spectroscopy; and Anodic Polarization. Results Electrochemical tests confirmed that most aggressive conditions to the Ti-6Al-4V alloy were those typical of occluded cells, i.e. oxidizing conditions (H2O2), in the presence of protein and deaeration of the physiological medium. Conclusions Our results provide evidence that titanium’s corrosion resistance can be reduced by intense inflammatory conditions. This observation indicates that the micro-environment to which the implant is exposed during peri-implant inflammation is highly aggressive and may lead to TiO2 passive layer attack. Further investigation of the effect of these aggressive conditions on titanium dissolution is warranted.

    Palavras-Chave: titanium alloys; implants; dentistry; corrosion protection; inflammation; infectious diseases; oral cavity; corrosion resistant alloys; electrochemistry; corrosion products


  • IPEN-DOC 26423

    BENTO, RODRIGO T. ; SILVA, ROGER W.O.; DIAS, LUCAS A.; FERRUS FILHO, ANDRE; PITTA, ANTONIO J.C.. Design, development and application of a real‑time capacitive sensor for automatically measuring liquid level. SN Applied Sciences, v. 1, n. 7, 2019. DOI: 10.1007/s42452-019-0770-3

    Abstract: In the present study a real-time capacitive sensor based on a capacitance step method is designed, developed and applied on measuring the liquid level by immersion. The capacitive sensor consists of two electrodes from copper plated phenolite plates separated by a gap distance and mounted inside a non-conductive storage tank. Water is used as the dielectric material. The analyzed sensor behavior with liquid level variation is semi-linear and obtained in function of the output voltage variation by using proper signal conditioning circuit. For converting the voltage variation into level variation, a parallel R–C circuit is used instead of conventional bridge circuit. Under suitable parameter settings it provided good reading accuracy. The experimental results demonstrate the high efficiency of the proposed model, which confirm the satisfactory performance of the capacitive sensor for liquid level measurement. The sensor presents an excellent ease of construction and installation, linked to the good measurements precision and high autonomy of system operation. The behavior experiments under different salt concentrations show that the water chemical composition does not interfere on the sensor operation. The proposed model exhibits a promising employment in several applications, such as control equipment for irrigation, biomedical area—in the interaction between antibody–antigen or protein-DNA, aerospace and pharmaceutical industry, gas sensors, and automation solutions.


  • IPEN-DOC 26422

    RODRIGUES, FLAVIO T. ; MARCHIONI, ERIC; LORDEL-MADELEINE, SONIA; KUNTZ, FLORENT; VILLAVICENCIO, ANNA L.C.H. ; JULIEN-DAVID, DIANE. Degradation of profenofos in aqueous solution and in vegetable sample by electron beam radiation. Radiation Physics and Chemistry, v. 166, p. 1-7, 2020. DOI: 10.1016/j.radphyschem.2019.108441

    Abstract: In this study, the role of accelerated electron irradiation on the removal of profenofos in aqueous solution and in peas was investigated. The samples were irradiated with a Rhodotron E-beam accelerator with 10 MeV energy at doses of 0 (control), 4.6, 12 and 32 kGy. Irradiated vegetable samples were extracted using a QuEChERS protocol (quick, easy, cheap, effective, rugged, and safe), allowing analysis of pesticide traces. Quantification of profenofos in aqueous solution was performed by using GC-MS in SIM mode and GC-MS/MS in MRM mode in vegetable sample. Degradation of profenofos increased with the E-beam dose and was much more important in aqueous solution than in vegetable. In irradiated aqueous solution, one degradation product was detected.


  • IPEN-DOC 26420

    BRANCACCIO, F. ; DIAS, M.S. ; KOSKINAS, M.F. ; MOREIRA, D.S. ; TOLEDO, F. de . Data analysis software package for radionuclide standardization with a digital coincidence counting system. Applied Radiation and Isotopes, v. 155, p. 1-10, 2020. DOI: 10.1016/j.apradiso.2019.108900

    Abstract: The Nuclear Metrology Laboratory (LMN) – IPEN, S~ao Paulo, Brazil – developed a Digital Coincidence System (DCS), based on the Coincidence Counting Methodology, in order to improve its capabilities in radionuclide primary-standardization. Digital process is implemented in two steps: data-acquisition (a set of measurements) and offline software data-analysis and calculation. The present work shows the basics of the data-acquisition unit (Software Coincidence System – SCS), describes the DCS’ data-analysis process and the initial approaches chosen for the implementation of the software package (Coincidence Analyzing Task – CAT). 152Eu standardization, performed for DCS testing, software expansion and validation, is briefly discussed.


  • IPEN-DOC 26419

    PRETTO, LUCAS R. de ; MOULT, ERIC M.; ALIBHAI, A.Y.; CARRASCO-ZEVALLOS, OSCAR M.; CHEN, SIYU; LEE, BYUNGKUN; WITKIN, ANDRE J.; BAUMAL, CAROLINE R.; REICHEL, ELIAS; FREITAS, ANDERSON Z. de ; DUKER, JAY S.; WAHEED, NADIA K.; FUJIMOTO, JAMES G.. Controlling for artifacts in widefield optical coherence tomography angiography measurements of non-perfusion area. Scientific Reports, v. 9, p. 1-15, 2019. DOI: 10.1038/s41598-019-43958-1

    Abstract: The recent clinical adoption of optical coherence tomography (OCT) angiography (OCTA) has enabled non-invasive, volumetric visualization of ocular vasculature at micron-scale resolutions. Initially limited to 3 mm × 3 mm and 6 mm × 6 mm fields-of-view (FOV), commercial OCTA systems now offer 12 mm × 12 mm, or larger, imaging fields. While larger FOVs promise a more complete visualization of retinal disease, they also introduce new challenges to the accurate and reliable interpretation of OCTA data. In particular, because of vignetting, wide-field imaging increases occurrence of low-OCT-signal artifacts, which leads to thresholding and/or segmentation artifacts, complicating OCTA analysis. This study presents theoretical and case-based descriptions of the causes and effects of low-OCTsignal artifacts. Through these descriptions, we demonstrate that OCTA data interpretation can be ambiguous if performed without consulting corresponding OCT data. Furthermore, using wide-field non-perfusion analysis in diabetic retinopathy as a model widefield OCTA usage-case, we show how qualitative and quantitative analysis can be confounded by low-OCT-signal artifacts. Based on these results, we suggest methods and best-practices for preventing and managing low-OCT-signal artifacts, thereby reducing errors in OCTA quantitative analysis of non-perfusion and improving reproducibility. These methods promise to be especially important for longitudinal studies detecting progression and response to therapy.

    Palavras-Chave: ophthalmology; retina; biomedical radiography; tomography; vascular diseases; optical equipment; coherent radiation; images; blood vessels; beam scanners


  • IPEN-DOC 26418

    SIMA, O.; DE VISMES OTT, A.; DIAS, M.S. ; DRYAK, P.; FERREUX, L.; GURAU, D.; HURTADO, S.; JODLOWSKI, P.; KARFOPOULOS, K.; KOSKINAS, M.F. ; LAUBENSTEIN, M.; LEE, Y.K.; LEPY, M.C.; LUCA, A.; MENEZES, M.O. ; MOREIRA, D.S. ; NIKOLIC, J.; PEYRES, V.; SAGANOWSKI, P.; SAVVA, M.I.; SEMMLER, R. ; SOLC, J.; THANH, T.T.; TYMINSKA, K.; TYMINSKI, Z.; VIDMAR, T.; VUKANAC, I.; YUCEL, H.. Consistency test of coincidence-summing calculation methods for extended sources. Applied Radiation and Isotopes, v. 155, p. 1-11, 2020. DOI: 10.1016/j.apradiso.2019.108921

    Abstract: An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.


  • IPEN-DOC 26417

    RIBEIRO, AMON S.L. ; ARATA, ANELYSE ; LIMA, NELSON B. de ; USSUI, VALTER ; LAZAR, DOLORES R.R. . Comparison of a laboratorial scale synthesized and a commercial yttria‐tetragonal zirconia polycrystals ceramics submitted to microwave sintering. International Journal of Applied Ceramic Technology, v. 16, n. 5, SI, p. 2020-2027, 2019. DOI: 10.1111/ijac.13310

    Abstract: Conventional sintering techniques of yttria‐tetragonal zirconia polycrystals (Y‐TZP) ceramics have presented limitations regarding the sintering time and temperature, increasing the cost of the final dental and biomedical products. Herein, microwave sintering comes to be an interesting alternative by providing fast heating, high densification, and grain‐size control. The aim of this study was to compare the effect of microwave sintering of Y‐TZP dental ceramics prepared from a pre‐sintered commercial block and produced from powders synthesized in a laboratorial scale by the precipitation route. The synthetized and commercial discs were submitted to microwave sintering at 1450°C and 1350°C for 15, 30, and 60 minutes. Densification, fracture toughness, grain size, and crystalline phase quantification of the sintered groups were evaluated. Both synthetized and commercial groups sintered at 1450°C for 15 and 30 minutes showed the higher densification results (98% TD). XRD quantitative phase analysis indicates that samples present 89% tetragonal and 11% cubic phases, except for the group prepared from coprecipitated powders sintered at 1450°C for 30 minutes, that presented 79% and 21% of tetragonal and cubic phases. The microwave sintering at 1450°C allows hardness and fracture toughness values comparable to conventional sintering.


  • IPEN-DOC 26415

    ZAHN, GUILHERME S. ; JUNQUEIRA, LUCAS S. ; GENEZINI, FREDERICO A. . CAX and Xsel: a software bundle to aid in automating NAA spectrum analysis. Brazilian Journal of Radiation Sciences, v. 7, n. 2A, p. 1-7, 2019. DOI: 10.15392/bjrs.v7i2A.565

    Abstract: In this work, the scripting capabilities of Genie-2000 were used to develop a software (CAX) that automatically anal-yses all spectrum files in either ORTEC's CHN or CANBERRA's MCA or CNF formats in a folder, generating two output files: a print-ready text file (.DAT) and a Comma-Separated Values (.CSV) file which can be easily imported in any major spreadsheet software. A second tool, named Xsel, consists in an EXCEL spreadsheet which automatically identifies the spectrum lines associated with the elements of interest, generating a clean output sheet which can be easily imported in a general spreadsheet that calculates the concentrations; an important addition to this spreadsheet is the ability to automatically recalibrate each spectrum, increasing the reliability of the peak identification procedure. These software tools are already used in daily routines at IPEN's Neutron Activation Laboratory, greatly reducing the time required for sample analyses, as well as reducing the possibility of transcription errors.

    Palavras-Chave: automation; neutron activation analysis; gamma radiation; gamma spectra; computer codes; calibration; performance; brazilian cnen; data processing


  • IPEN-DOC 26414

    SCAGLIUSI, SANDRA R. ; CARDOSO, ELIZABETH C.L. ; ESPER, FABIO ; LUGAO, ADEMAR B. . Butyl rubber recycling via gamma radiation followed by mechanical shear. Ecology, Pollution and Environmental science: Open Access (EEO), v. 1, n. 4, p. 84-88, 2018.

    Abstract: Polymeric materials (plastics and rubber) have been contributing in a continuously and raising way for the generation of litter and industrial wastes discarded in landfills. The implementation of new technologies for the reduction of polymeric materials, acceptable from the environmental viewpoint and at an effective cost, proved to be a great problem, due to complexities inherent for the re-use, especially of rubbers. Gamma ionizing radiation has capacity for changing structure and properties of polymeric materials and can be applied to almost all types of polymers; irradiation is an expectation for problem-solving of rubber wastes management that can be utilized as raw-materials or chemical additives. The relatively low degree of unsaturation presented by butyl rubber (IIR) is responsible for the great resistance of butyl rubber to oxygen, ozone and heat, as well as low gas and water vapor permeability. At the initial stage of irradiation, the degradation of bromobutyl rubber occurs predominantly via random chain-scission and chain-crosslinking may occur caused from the isoprene copolymerized units. This work aims to the introduction of a new recovery technique for bromobutyl rubber, by using processing via gamma rays followed by shear. Rubber was irradiated at 0 kGy, 5 kGy, 15 kGy, 25 kGy, 50 kGy, 100 KGy, 150 kGy and 200 KGy doses, in order to study the feasibility of bromobutyl rubber for recycling. 25 kGy doses, applied to butyl rubber further sheared, pointed toward a less degraded material, indicating that this type of elastomer is able to be incorporated to a new rubber compound and replacing some parts of pristine rubber in formulations without imparting great losses in physical-chemical properties.


  • IPEN-DOC 26413

    COELHO, GUILHERME R.; PREZOTTO NETO, PEDRO ; BARBOSA, FERNANDA C.; SANTOS, RAFAEL S. dos; BRIGATTE, PATRICIA; SPENCER, PATRICK J. ; SAMPAIO, SANDRA C.; D’AMELIO, FERNANDA; PIMENTA, DANIEL C.; SCIANI, JULIANA M.. Biochemical and biological characterization of the Hypanus americanus mucus: a perspective on stingray immunity and toxins. Fish and Shellfish Immunology, v. 93, p. 832-840, 2019. DOI: 10.1016/j.fsi.2019.08.049

    Abstract: Stingrays skin secretions are largely studied due to the human envenoming medical relevance of the sting puncture that evolves to inflammatory events, including necrosis. Such toxic effects can be correlated to the biochemical composition of the sting mucus, according to the literature. Fish skin plays important biological roles, such as the control of the osmotic pressure gradient, protection against mechanical forces and microorganism infections. The mucus, on the other hand, is a rich and complex fluid, acting on swimming, nutrition and the innate immune system. The elasmobranch's epidermis is a tissue composed mainly by mucus secretory cells, and marine stingrays have already been described to present secretory glands spread throughout the body. Little is known about the biochemical composition of the stingray mucus, but recent studies have corroborated the importance of mucus in the envenomation process. Aiming to assess the mucus composition, a new noninvasive mucus collection method was developed that focused on peptides and proteins, and biological assays were performed to analyze the toxic and immune activities of the Hypanus americanus mucus. Pathophysiological characterization showed the presence of peptidases on the mucus, as well as the induction of edema and leukocyte recruitment in mice. The fractionated mucus improved phagocytosis on macrophages and showed antimicrobial activity against T. rubrumç. neoformans and C. albicans in vitro. The proteomic analyses showed the presence of immune-related proteins like actin, histones, hemoglobin, and ribosomal proteins. This protein pattern is similar to those reported for other fish mucus and stingray venoms. This is the first report depicting the Hypanus stingray mucus composition, highlighting its biochemical composition and importance for the stingray immune system and the possible role on the envenomation process.

    Palavras-Chave: fishes; skin; secretion; animal tissues; hazardous materials; venoms; proteins; biochemistry; antimicrobial agents; biological materials; immune reactions; immunity


  • IPEN-DOC 26410

    OTTONI, CRISTIANE A.; SIMÕES, MARTA F.; SANTOS, JONAS G.; PEIXOTO, LUCIANA; MARTINS, CLEITON R.; SILVA, BRUNO P.; NETO, ALMIR O. ; BRITO, ANTONIO G.; MAIORANO, ALFREDO E.. Application of microbial fuel cell technology for vinasse treatment and bioelectricity generation. Biotechnology Letters, v. 41, n. 1, p. 107-114, 2019. DOI: 10.1007/s10529-018-2624-2

    Abstract: Objective Our study evaluated the performance of different two-chambered microbial fuel cell (MFC) prototypes, operated with variable distance between electrodes and Nafion membrane and specific inoculum concentration, applied for vinasse treatment. Results The performance of the developed MFC resulted in a maximum current density of 1200 mA m-2 and power density of 800 mW m-2 in a period of 61 days. MFC performed a chemical oxygen demand removal at a rate ranging from 51 to 60%. Conclusions Taking our preliminary results into consideration, we concluded that the MFC technology presents itself as highly promising for the treatment of vinasse.


  • IPEN-DOC 26409

    IZIDORO, JULIANA ; CASTANHO, DAVI ; ROSSATI, CARLOS ; FUNGARO, DENISE ; GUILHEN, SABINE ; NOGUEIRA, THIAGO; ANDRADE, MARIA de F.. Application of high-purity zeolite a synthesized from different coal combustion by-products in carbon dioxide capture. International Journal of Environmental Impacts, v. 2, n. 3, p. 215-228, 2019. DOI: 10.2495/EI-V2-N3-215-228

    Abstract: High-purity zeolites A were synthesized from different coal combustion by-products (baghouse filter fly ash, cyclone filter ash, and bottom ash) and characterized in terms of morphology, chemical, and mineralogical composition. The products were tested for carbon dioxide capture by using a continuous CO2 flow system passing through a column packed with the adsorbent material, which was connected to an analyser that directly measures the concentration of CO2. The values of CO2 adsorption capacities calculated for the unmodified Na-A zeolites (ZABF, ZACF, and ZABA) were 556.48, 494.29 and 654.82 mg g–1, respectively. These values were higher than those achieved by the calcium-modified zeolite samples. ZABA adsorbent presented the best performance in CO2 capture when compared to the other adsorbent material and achieved an adsorption capacity 32% higher than a 4A commercial zeolite. In the adsorption cycles study, the percentage of CO2 desorption by ZABA at the second and third cycles reached 93%, showing that zeolite A can be regenerated by heating at 150 ºC. The use of coal ashes to obtain zeolites and the application of these products for the CO2 adsorption can be an important strategy to mitigate both the problem of waste management and the greenhouse gases emission in coal-fired power plants.


  • IPEN-DOC 26406

    GUILHEN, SABINE N. ; COTRIM, MARYCEL E.B. ; SAKATA, SOLANGE K. ; SCAPIN, MARCOS A. . Application of the fundamental parameter method to the assessment of major and trace elements in soil and sediments from Osamu Utsumi uranium mine by WDXRF. REM - International Engineering Journal, v. 72, n. 4, p. 609-617, 2019. DOI: 10.1590/0370-44672018720146

    Abstract: Wavelength dispersive X-ray fluorescence spectrometry (WDXRF) is a suitable technique for the characterization of contaminated mining sites, providing a quick and reliable screening for areas of significant contamination. This study established and validated a non-destructive methodology for quantitative simultaneous determination of major and minor constituents in soil and sediments by WDXRF, which was further applied to quantify soil and sediment samples from Osamu Utsumi uranium mine (Caldas, Minas Gerais, Brazil). Elements such as Ce, La, Nd, Mn and U were found in more concentrated levels in the calcium diuranate deposit (DUCA), whereas Fe and Al were found at higher levels in the soil samples corresponding to sites where accentuated leaching processes have occurred. Comparatively, the levels of U and rare-earth elements were found in significantly higher levels in the sediments retrieved from the mine’s pit as a result of acid mine drainage. These findings are believed to be useful as an initial environmental assessment for the decommissioning process of the mine.


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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.


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, .

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).



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.