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  • IPEN-DOC 27755

    MOREIRA, GREGORI de A. ; ANDRADE, IZABEL da S. ; CACHEFFO, ALEXANDRE ; LOPES, FABIO J. da S. ; YOSHIDA, ALEXANDRE C. ; GOMES, ANTONIO A. ; SILVA, JONATAN J. da ; LANDULFO, EDUARDO . Influence of a biomass-burning event in PM2.5 concentration and air quality: a case study in the Metropolitan Area of São Paulo. Sensors, v. 21, n. 2, p. 1-19, 2021. DOI: 10.3390/s21020425

    Abstract: Severe biomass burning (BB) events have become increasingly common in South America in the last few years, mainly due to the high number of wildfires observed recently. Such incidents can negatively influence the air quality index associated with PM2.5 (particulate matter, which is harmful to human health). A study performed in the Metropolitan Area of São Paulo (MASP) took place on selected days of July 2019, evaluated the influence of a BB event on air quality. Use of combined remote sensing, a surface monitoring system and data modeling and enabled detection of the BB plume arrival (light detection and ranging (lidar) ratio of (50 ± 34) sr at 532 nm, and (72 ± 45) sr at 355 nm) and how it affected the Ångström exponent (>1.3), atmospheric optical depth (>0.7), PM2.5 concentrations (>25 µg.m−3), and air quality classification. The utilization of high-order statistical moments, obtained from elastic lidar, provided a new way to observe the entrainment process, allowing understanding of how a decoupled aerosol layer influences the local urban area. This new novel approach enables a lidar system to obtain the same results as a more complex set of instruments and verify how BB events contribute from air masses aloft towards near ground ones.

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  • IPEN-DOC 27754

    SANTOS, ALLAN O.; RICCIARDI, JANAINA B.S.; PAGNANO, RODRIGO; PEREIRA, LUIS F.M.; SAKUMA, EMERSON T.; MATSUDA, MARGARETH M.N. ; BERNARDES, EMERSON S. ; ARAUJO, ELAINE B. ; BRUNETTO, SERGIO Q.; TAKAHASHI, MARIA E.S.; BRUNETTO, EDNA M.; ZULLI, ROBERTO; OZELO, MARGARETH C.; ETCHEBEHERE, ELBA C.S.C.. Knee radiosynovectomy with 153Sm‑hydroxyapatite compared to 90Y‑hydroxyapatite: initial results of a prospective trial. Annals of Nuclear Medicine, v. 35, n. 2, p. 232-240, 2021. DOI: 10.1007/s12149-020-01557-5

    Abstract: Introduction Radiosynovectomy (RS) with 90Y-hydroxyapatite (90Y-HyA) aims to control knee hemarthrosis in hemophiliac patients to prevent secondary arthropathy. However, knee RS using 153Sm-hydroxyapatite (153Sm-HyA) is considered less suitable due to the lower average soft tissue range and energy of 153Sm for large joints, such as the knees. Purpose The objective of this investigation was to assess the efficacy and safety of knee RS with 153Sm-HyA, compared to 90Y-HyA. Methods Forty patients were prospectively assigned to undergo knee RS with 153Sm-HyA (n = 19) or with 90Y-HyA (n = 21). The frequency of hemarthrosis episodes before and after treatment were compared. Results After six months of knee RS, 153Sm-HyA and 90Y-HyA promoted a similar reduction of hemarthrosis episodes (50% and 66.7%, respectively). However, after 12 months of knee RS, the reduction of hemarthrosis episodes was significantly (p = 0.037) higher using 153Sm-HyA (87.5%) compared to 90Y-HyA (50.0%). This discrepancy was more pronounced (p = 0.002) for 153Sm-HyA compared to 90Y-HyA in adults/adolescents. Conclusion Knee radiosynovectomy with 153Sm-HyA is safe, reduces hemarthrosis episodes after 12 months of treatments, especially in adults/adolescents and even with grades III/IV arthropathy, similar to 90Y-HyA. 90Y-HyA seems to promote better hemarthrosis control in small children.

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  • IPEN-DOC 27753

    KOHATSU, MARCIO Y.; PELEGRINO, MILENA T.; MONTEIRO, LUCILENA R. ; FREIRE, BRUNA M.; PEREIRA, RODRIGO M.; FINCHEIRA, PAOLA; RUBILAR, OLGA; TORTELLA, GONZALO; BATISTA, BRUNO L.; JESUS, TATIANE A. de; SEABRA, AMEDEA B.; LANGE, CAMILA N.. Comparison of foliar spray and soil irrigation of biogenic CuO nanoparticles (NPs) on elemental uptake and accumulation in lettuce. Environmental Science and Pollution Research, v. 28, n. 13, p. 16350-16367, 2021. DOI: 10.1007/s11356-020-12169-x

    Abstract: Nanoparticles (NPs) can be used in several ways in agriculture, including increasing production rates and improving nutritional values in plants. The present study aims to clarify how biogenic copper oxide nanoparticles (CuO NPs) applied by two routes of exposure (foliar spray and soil irrigation) affect the elemental uptake by lettuce. In vivo experiments using lettuce (n = 4) were performed with CuO NPs in comparison with copper salt (CuSO4), considering a final mass added of 20 mg of CuO per plant. The elemental composition of roots was mostly affected by the soil irrigation exposure for both Cu forms (NPs and salt). Neither Cu form added by soil irrigation was translocated to leaves. Copper concentration in leaves was mainly affected by foliar spray exposure for both Cu forms (NPs and salt). All Cu forms through foliar spray were sequestered in the leaves and no translocation to roots was observed. Foliar spray of CuO NPs caused no visual damage in leaves, resulted in less disturbance of elemental composition, and improved dry weight, number of leaves, CO2 assimilation, and the levels of K, Na, S, Ag, Cd, Cr, Cu, and Zn in leaves without causing significant changes in daily intake of most elements, except for Cu. Although Cu concentration increased in leaves by foliar spray of CuO NPs, it remained safe for consumption.

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  • IPEN-DOC 27752

    ALMEIDA, JORGE V. de; SILVA, EDUARDO C. da; MOSSO, MARBEY M.; SARTORI, CARLOS A.F. . A parametric study of inductive SWIPT systems assisted by metamaterial using virtual magnetic TL-based channel modeling. Journal of Microwaves, Optoelectronics and Electromagnetic Applications, v. 20, n. 1, p. 195-207, 2021. DOI: 10.1590/2179-10742021v20i1995

    Abstract: This paper presents a general methodology based on the description of the inductive channel as virtual magnetic transmission-lines (VMGTLs). In comparison with other existing methods, VMGTL approach presents a better physical insight of the channel behavior since the model correctly preserves the energy flow between the transmitting and receiving coils. Besides that, it facilitates the integration into the analysis of highly nonlinear and dispersive structures such as metamaterial (MTM) lenses. Particularly, the virtual-TL analogy clarifies that the enhancement of the transmission gain between any two coils assisted by MTM is not due to an enhanced coupling between the drivers, as usually claimed, but to the emergence of propagating near-field modes supported by the MTM. This approach, by means of a parametric study, also indicates, for the first time, that MTMs could be employed not only for the increasing of power but also of data transfer due to the emergence of a sub-resonant region of minimum distortion. Nonetheless, since both effects are mutually exclusive, no passive MTM structure could simultaneously improve power and data transmission.

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  • IPEN-DOC 27751

    SALES, T.S.N. ; BURIMOVA, A. ; RODRIGUES, P.S. ; MATOS, I.T. ; CABRERA-PASCA, G.A.; SAXENA, R.N. ; PEREIRA, L.F.D. ; OTUBO, L. ; CARBONARI, A.W. . Synthesis and characterization of Fe3O4-HfO2 nanoparticles by hyperfine interactions measurements. AIP Advances, v. 11, n. 1, p. 015047-1 - 015047-4, 2021. DOI: 10.1063/9.0000235

    Abstract: Nanoparticles (NPs) that combine biocompatibility and enhanced physical characteristics for biomedical applications are currently an area of intense scientific research. Hafnium oxide NPs are an innovative approach in the anticancer treatment by radiotherapy due to their low toxicity and enhancement of local dose in the tumor reducing the total radiation dose for the patient. The combination of this property with the excellent magnetic hyperthermia performance of Fe3O4 NPs can produce a promising nanomaterial for cancer therapy. In this work, we attempted to synthesize nanoscale samples of HfO2 doped with nominal 10 at.% Fe, and Fe3O4 doped with Hf at 10 at.% level using simple chemical routes. The crystal structure of the samples was characterized by X-ray diffraction. The material was irradiated with neutrons in a research reactor, the nuclear reaction 180Hf(n, γ)181Hf yielding the probe nucleus 181Hf(181Ta) used in the perturbed angular correlations experiments to measure hyperfine interactions. Despite their immediate response to the external magnetic field, at local level both samples showed only electric quadrupole interaction typical of the monoclinic hafnia indicating that Fe replaces Hf in HfO2 NPs, but, rather than substituting Fe, Hf enters magnetite in the form of HfO2 clusters. Transmission Electron Microscopy was exploited to study the morphology of these complex systems, as well as to localize hafnia clusters and understand the nature of their coupling to Fe3O4 specks.

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  • IPEN-DOC 27750

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L. ; BRANDAO, JAQUELINE de S.; PFEIFER, JOAO P.H.; ROSA, GUSTAVO dos S.; SILVA, WILLIAM de M.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Physical and biological characterizations of TiNbSn/(Mg) system produced by powder metallurgy for use as prostheses material. Journal of the Mechanical Behavior of Biomedical Materials, v. 115, p. 1-10, 2021. DOI: 10.1016/j.jmbbm.2020.104260

    Abstract: Titanium scaffolds with non-toxic β stabilizing elements (Nb and Sn), Ti–34Nb–6Sn (TNS), and with magnesium as spacer (TNS/M), were processed by powder metallurgy, and sintered at 800 ◦C. The X-ray diffraction (XRD) pattern showed that materials are biphasic alloys, presenting 45 to 42% (wt %) in hcp (α-phase) and the rest is bcc (β-phase), and the presence of a slight peak relating to TiO2 in both materials. Pores of approximately 50 μm for TNS and 300 μm to TNS/M were observed in the micrographic analysis by scanning electron microscopy (SEM). The wettability was higher for TNS/M compared to TNS. The elastic modulus was higher for TNS compared to TNS/M. Stem cells derived from equine bone marrow (BMMSCs) were used for in vitro assays. The morphologic and adhesion evaluation after 72 h, carried out by direct contact assay with the materials showed that the BMMSCs were anchored and adhered to the porous scaffolds, in the way the cytoplasmic extension was observed. The cellular migration, using the “wound healing” method, was significant for the groups treated with conditioned medium with materials in 24 h. Osteogenic differentiation of BMMSCs, assessed by calcium deposition and staining with Alizarin Red, was greater in the conditioned medium with TNS/M in 10 days of culture. Since the biological effects was good and the elastic modulus decreased in the system with magnesium is a promising new content titanium alloy for biomedical application.

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  • IPEN-DOC 27745

    ASFORA, VIVIANE K.; ANTONIO, PATRICIA L. ; GONCALVES, JOSEMARY A.C. ; BUENO, CARMEN C. ; BARROS, VINICIUS S.M. de; OLIVEIRA, CHARLES N.P.; CALDAS, LINDA V.E. ; KHOURY, HELEN J.. Evaluation of TL and OSL responses of CaF2:Tm for electron beam processing dosimetry. Radiation Measurements, v. 140, p. 1-8, 2021. DOI: 10.1016/j.radmeas.2020.106512

    Abstract: The thermoluminescence (TL) and infrared stimulated luminescence (IRSL) responses of in-house produced CaF2:Tm dosimeters are investigated in this work, envisaging their application in electron beam (EB) radiation processing. The irradiations were performed at an industrial EB accelerator (1.5 MeV) covering a dose rate range of 2–8 kGy/s and dose up to 10 kGy. In general, the TL glow curves display four peaks, termed as peaks 2, 3, 4, and 5, corresponding to temperatures at ~150, 200, 240, and 300 °C, respectively. The intensity of the low-temperature peaks (2 and 3) grows with the dose, while the others remain constant (saturated). Nevertheless, an evident dose effect on the glow curves manifests in decreased peak3/peak2 ratio with increasing doses. The CW-IRSL curves exhibit similar patterns with an initial signal increase, followed by an exponential decay. Instead of the normal monotonic decays, these peak-shaped curves might be due to the charge capture competition between empty shallow traps and recombination centers. Both TL and IRSL intensities increase linearly with doses up to 6 kGy, and for higher doses, they become sub-linear with a saturation trend around 10 kGy. Another common feature of TL/IRSL response is its dose rate dependence, being more sensitive at higher dose rates. Despite being dose-rate dependent, the CaF2:Tm dosimeters might be suitable for EB processing dosimetry. However, for their use as routine dosimeters, relevant dosimetric characteristics, such as fading and response reproducibility, have to be investigated. Work in this direction is underway.

    Palavras-Chave: thermoluminescence; infrared radiation; luminescence; electron dosimetry; calcium fluorides; dosimetry; irradiation; evaluation

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  • IPEN-DOC 27744

    DUARTE, EDICLE de S.F.; FRANKE, PHILIPP; LANGE, ANNE C.; FRIESE, ELMAR; LOPES, FABIO J. da S. ; SILVA, JONATAN J. da ; REIS, JEAN S. dos; LANDULFO, EDUARDO ; SILVA, CLAUDIO M.S. e; ELBERN, HENDRIK; HOELZEMANN, JUDITH J.. Evaluation of atmospheric aerosols in the metropolitan area of São Paulo simulated by the regional EURAD-IM model on high-resolution. Atmospheric Pollution Research, v. 12, n. 2, p. 451-469, 2021. DOI: 10.1016/j.apr.2020.12.006

    Abstract: We present a high-resolution air quality study over São Paulo, Brazil with the EURopean Air Pollution Dispersion - Inverse Model (EURAD-IM) used for the first time over South America simulating detailed features of aerosols. Modeled data are evaluated with observational surface data and a Lidar. Two case studies in 2016 with distinct meteorological conditions and pollution plume features show transport (i) from central South America, associated to biomass burning activities, (ii) from the rural part of the state of São Paulo, (iii) between the metropolitan areas of Rio de Janeiro and São Paulo (MASP) either through the Paraíba Valley or via the ocean, connecting Brazil's two largest cities, (iv) from the port-city Santos to MASP and also from MASP to the city Campinas, and vice versa. A Pearson coefficient of 0.7 was found for PM10 at MASP CENTER and EURAD-IM simulations vary within the observational standard deviation, with a Mean Percentual Error (MPE) of 10%. The model's vertical distributions of aerosol layers agree with the Lidar profiles that show either characteristics of long-range transported biomass burning plumes, or of local pollution. The distinct transport patterns that agree with satellite Aerosol Optical Death and fire spot images as well as with the ground-based observations within the standard deviations, allows us exploring patterns of air pollution in a detailed manner and to understand the complex interactions between local to long-range transport sources.

    Palavras-Chave: air pollution; urban areas; evaluation; aerosols; atmospheres; air pollution monitoring; combustion; environmental impacts

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  • IPEN-DOC 27743

    COSTA, OSVALDO L. da ; SOUZA, DAIANE C.B. de ; CASTANHO, FABIO G. ; FEHER, ANSELMO ; MOURA, JOÃO A. ; SOUZA, CARLA D. ; OLIVEIRA, HENRIQUE B. ; MADUAR, MARCELO F. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Gamma spectrometry of iodine-125 produced in IEA-R1 nuclear reactor, using HPGe detector and fixation into epoxy matrix disc. Applied Radiation and Isotopes, v. 169, p. 1-6, 2021. DOI: 10.1016/j.apradiso.2020.109568

    Abstract: Few places in the world produce iodine-125. In Brazil, the first production was achieved by using the IEA-R1 nuclear reactor located at Nuclear and Energy Research Institute – IPEN. To verify the quality of iodine-125 produced, and the amount of contaminants such as iodine-126, cesium-134 and caesium-137 among others, iodine-125 samples were immobilized into epoxy matrix disc, with the same geometry of a barium-133 reference radioactive source, used to calibrate an HPGe detector. The HPGe detector has a thin carbon composite window, which allows measure the iodine-125 photopeaks, between 27.1 and 35.4 keV. The method employed here was successful in producing and measurement of iodine-125.

    Palavras-Chave: contamination; gamma spectroscopy; high-purity ge detectors; iodine 125; irradiation; quality control; volatility; brazilian cnen

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  • IPEN-DOC 27742

    MIRANDA, ANA C.C. ; DURANTE, ANA C.R.; FUSCALDI, LEONARDO L.; BARBEZAN, ANGELICA B. ; LIMA, CILENE R. de; PERINI, EFRAIN ; ARAUJO, ELAINE B. de . Anti-HER2 monoclonal antibody based-radioimmunoconjugates: assessment of the chelating agent influence. Bioorganic & Medicinal Chemistry, v. 33, p. 1-9, 2021. DOI: 10.1016/j.bmc.2021.115996

    Abstract: In the present work, the radioimmunoconjugates 111In-DTPA-trastuzumab and 177Lu-DOTA-trastuzumab were evaluated regarding the influence of the chelating agents on the physical–chemical parameters and human epidermal growth factor receptor 2 (HER2) tumor cell binding. Data showed that both chelating agents, at predetermined molar ratios (antibody:chelator 􀀀 1:10 and 1:20), did not influence the immunoconjugates integrity, the radiolabeling process and the radiolabeled antibodies stability. However, differences were observed in the lipophilic feature between DOTA and DTPA radioimmunoconjugates and in the specific binding to SK-BR-3 tumor cells (HER2 positive). Therefore, this study showed the importance of assessing the influence of chelating agents and their molar ratios in the development process of radioimmunoconjugates.

    Palavras-Chave: tumor cells; neoplasms; drugs; therapeutic uses; radioimmunotherapy; chelating agents; radioisotopes

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  • IPEN-DOC 27741

    FONTES, E.H. ; RAMOS, C.E.D. ; OTTONI, C.A.; SOUZA, R.F.B. de ; ANTOLINI, E.; NETO, A.O. . Glycerol dehydrogenation steps on Au/C surface in alkaline medium: an in-situ ATR-FTIR approach. Renewable Energy, v. 167, p. 954-959, 2021. DOI: 10.1016/j.renene.2020.12.026

    Abstract: The glycerol oxidation reaction (GLYOR) was evaluated using an Au/C electrocatalyst under alkaline conditions and varying glycerol (GLY) concentration. This electrocatalyst was synthesized by the borohydride reduction method. Au/C was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and electrochemical techniques associated with in situ attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR). XRD diffractograms showed the presence of Au (fcc). Cyclic voltammetry assisted by ATR-FTIR in situ measurements revealed that GLY oxidation on gold leads to the formation of a high amount of glyceraldehyde (GLYAD) for low GLY concentrations, while a lower amount of GLYAD was observed and the formation of dihydroxyacetone (DHA) was prevalent for high GLY concentrations. For high GLY concentrations DHA is almost stable, whereas for low GLY concentration DHA is fast oxidized to hydroxypyruvate. The excellent GLYOR activity of the Au/C catalyst in low GLY concentrations leads to the formation of deeper oxidized C1 species.

    Palavras-Chave: glycerol; dehydrogenation; gold; carbon; infrared spectrometers; fourier transform spectrometers; integral equations; oxidation; electrocatalysts; monosaccharides

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  • IPEN-DOC 27740

    SILVA, ANDERSON M.B.; SILVEIRA, WELLISSON S.; MATOS, TAWANY S.; JUNOT, DANILO O. ; REZENDE, MARCOS V.S.; SOUZA, DIVANIZIA N.. Effect of terbium and silver co-doping on the enhancement of photoluminescence in CaSO4 phosphors. Optical Materials, v. 111, p. 1-8, 2021. DOI: 10.1016/j.optmat.2020.110717

    Abstract: In this work, the photoluminescence properties of CaSO4 crystals co-doped with terbium and silver from silver oxide or silver nanoparticles (NPs) in different concentrations are investigated. Phosphors are obtained by means of a slow evaporation route and calcined at 600 °C for 1 h. X-ray diffraction analysis shows the formation of a single-phase anhydrite structure with orthorhombic symmetry. The photoluminescence properties are investigated using vacuum ultraviolet, ultraviolet and X-ray excitation. All luminescent measurements reveal the characteristic emissions of Tb3+. The analyses using excitation with ultraviolet light show that the Ag NPs are able to generate structural defects more satisfactorily compared to CaSO4:Tb with silver oxide. We also observe that higher concentrations of Ag increase the Tb3+ emission intensity, while higher concentrations of Ag NPs decrease it. The good stability of CaSO4 results in an efficient energy transfer from the host lattice to the activator under X-ray excitation, with the NPs contributing to the increase in luminescent intensity. Investigation of the terbium valence in the CaSO4 host shows a complete reduction of the Tb4+ present in Tb4O7 to Tb3+, as indicated by the X-ray absorption near edge structure. The vacuum ultraviolet excitation spectra reveal three broad bands, attributed to the charge-transfer excitations within SO42− complexes and to the 4f8 → 4f75d1 transitions on Tb3+. Our results also reveal that silver particles are responsible for generating deeper capture centers.

    Palavras-Chave: calcium sulfates; terbium; silver; phosphors; doped materials; photoluminescence; optical properties; crystals; nanoparticles; x-ray diffraction; ultraviolet radiation

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  • IPEN-DOC 27739

    MARUM, VICTOR J. de O.; REIS, LIVIA B.; MAFFEI, FELIPE S.; RANJBARZADEH, SHAHIN; KORKISCHKO, IVAN ; GIORIA, RAFAEL dos S.; MENEGHINI, JULIO R.. Performance analysis of a water ejector using Computational Fluid Dynamics (CFD) simulations and mathematical modeling. Energy, v. 220, p. 1-9, 2021. DOI: 10.1016/j.energy.2021.119779

    Abstract: A quasi-one-dimensional (1D) mathematical model coupled with Computational Fluid Dynamics (CFD) simulations of a water ejector is presented. Using data from CFD simulations, the mathematical model was used to calculate the friction loss coefficients of the ejector components, to predict its maximum efficiency point and to delimit its envelope of operation. The CFD approach was validated with experimental data and employed the finite element method to test the main turbulence models found in the literature (k-ε, k-u and k-u SST) for incompressible-flow ejectors. A set of operational conditions (OP) was tested and results show that the k-u SST turbulence model is the most suitable to capture the ejector flow characteristics in all OP. In addition, for higher entrainment ratio (M) values, it was observed a possible correlation between how well the boundary layer can be solved and how the model is able to capture the ejector efficiency curve. Moreover, for lower M values, another possible correlation may be stated between how the turbulence model is able to capture the velocity profile.

    Palavras-Chave: computerized simulation; fluid mechanics; mathematical models; performance testing; efficiency; water; friction

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  • IPEN-DOC 27738

    SANTOS, DIOGO F. dos ; SANTOS, ADIMIR dos . Zero-power noise up to 100 kHz in the IPEN/MB-01 research reactor facility. Annals of Nuclear Energy, v. 152, p. 1-16, 2021. DOI: 10.1016/j.anucene.2020.107974

    Abstract: Subcritical noise experiments at frequencies up to 100 kHz employing two distinct boron dilution in the reactor tank water (286.8 and 578.6 ppm of natural boron) were performed in the IPEN/MB-01 reactor. The Auto Power Spectral Densities (APSD) were inferred employing the IPEN/MB-01 Correlator and were best described by a four-mode decay model up to about 70 kHz. The analyses reveal that the first two modes were related to thermal neutron and the other two to the fast ones. The coupling between thermal and fast neutrons was weak, and they could be considered uncoupled. A two-region two-group kinetic model was built and for the first time important parameters, such as the subcritical reactivities, generation times, and the prompt neutron decay constants all in the core and reflector in the 286.8 ppm case were inferred. The experiments can be considered unique of its kind and the theory/experiment comparisons reached good agreements.

    Palavras-Chave: zero power reactors; reactor noise; ipen-mb-1 reactor; spectral density; criticality; frequency measurement; lifetime; neutrons

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  • IPEN-DOC 27737

    BENTO, RODRIGO T. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . On the surface chemistry and the reuse of sulfur-doped TiO2 films as photocatalysts. Materials Chemistry and Physics, v. 261, p. 1-7, 2021. DOI: 10.1016/j.matchemphys.2021.124231

    Abstract: The surface chemistry and recyclability of sulfur-doped titanium dioxide (TiO2) films was evaluated. The photocatalysts were grown by metalorganic chemical vapor deposition (MOCVD) at 400 ◦C. The films were sulfur-doped at 50 ◦C by using hydrogen sulfide (H2S) as sulfur source. The photocatalytic behavior of the films was measure by monitoring the methyl orange dye decolorization under visible light for several cycles. The films are formed only for the anatase crystalline phase. The results demonstrated that no structural modifications or significant differences in the morphology of the films occurred after their use. The sulfur-doped TiO2 films presented good photocatalytic activity, with an efficiency of 72.1% under visible light in its first use. The durability experiments suggest that even with the dye impregnation on the catalyst surface, the photocatalytic activity of the S-doped TiO2 films remained around 70% in the first 3 cycles, which allows their practical application for water treatment and purification under sunlight.

    Palavras-Chave: titanium oxides; sulfur; doped materials; films; vapor phase epitaxy; recycling; photocatalysis; surfaces; chemical vapor deposition

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  • IPEN-DOC 27736

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Towards a new promising dosimetric material from formation of thulium-yttria nanoparticles with EPR response. Materials Chemistry and Physics, v. 259, p. 1-7, 2021. DOI: 10.1016/j.matchemphys.2020.124005

    Abstract: Advances toward new materials for dosimetry application is essential to enhance quality assurance and quality improvement practices based on radiation protection concept. Face to this challenge the present work reports an approach to produce thulium-yttria nanoparticles with electron paramagntic resonance response by an alternative hydrothermal synthesis based on a relative low temperature and pressure. Distinct compositions of thulium-yttria nanoparticles with up to 2 at.%Tm (at.%, atomic percentage) were prepared and characterized by XRD, SEM, PCS, and EPR. The proposed synthesis method followed by thermal treatment of the precursor powder at 1100 ◦C for 2 h provided thulium-yttria nanoparticles with rounded shape, cubic C-type structure, and mean particle size (d50) less than 160 nm. Among all compositions formed, thulium-yttria nanoparticles prepared with 0.1%Tm presented the most remarkable EPR response. The production of fine thulium-yttria nanoparticles with EPR response supply meaningful parameters to advance in the formation of new dosimetry materials based on rare earths.

    Palavras-Chave: dosimetry; thulium oxides; yttrium; nanoparticles; rare earths; electron paramagnetic resonance; ceramics

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  • IPEN-DOC 27735

    ANDRADE, LUANA dos S.; OTUBO, LARISSA ; CASTANHEIRA, BRUNA; BROCHSZTAIN, SERGIO. Novel periodic mesoporous organosilicas containing pyromellitimides and their application for the photodegradation of asphaltenes. Microporous and Mesoporous Materials, v. 312, p. 1-8, 2021. DOI: 10.1016/j.micromeso.2020.110740

    Abstract: Periodic mesoporous organosilicas containing pyromellitic diimide units embedded in the pore walls (PMOPMI) were synthesized by co-condensation of the bridged silsesquioxane precursor N,N′-bis(3-triethoxysilylpropyl)pyromellitimide with tetraethoxysilane (TEOS) in acidic conditions, in the presence of the structure-directing agent Pluronics P-123. PMOPMI were also synthesized from the corresponding amic acid precursors. The PMOPMI were studied by different techniques, including N2 adsorption isotherms, transmission electron microscopy, infrared and diffuse reflectance spectroscopy and contact angles. The studied samples displayed well-organized 2D-hexagonal structures. The PMOPMI were able to adsorb petroleum asphaltenes from toluene solutions, and were efficient photosensitizers for the photodegradation of the adsorbed asphaltenes when irradiated. Most of the asphaltenes were removed from solutions by the combined action of adsorption and photodegradation processes.

    Palavras-Chave: porous materials; silica; nanocomposites; asphaltenes; photocatalysis; petroleum; ultraviolet radiation

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  • IPEN-DOC 27734

    GOTARDO, ANDRE T.; LIPPI, LUCIANA L.; VIOLIN, KALAN B. ; BEVILACQUA, ESTELA M.A.F.; GORNIAK, SILVANA L.. The effect of Ipomoea carnea on maternal reproductive outcomes and fetal and postnatal development in rats. Toxicon, v. 190, p. 3-10, 2021. DOI: 10.1016/j.toxicon.2020.11.012

    Abstract: Ipomoea carnea is a toxic plant found in Brazil and other tropical countries. The plant contains the alkaloids calystegines and swainsonine, which inhibit key cellular enzymes and cause systematic cell death. It is known that swainsonine is excreted in the amniotic fluid of dams exposed to the plant. Thus, the aim of this study was to verify whether the toxic effect of I. carnea on fetuses is due to exclusively the passage of the active principle of the plant through the placenta, or if the placentotoxic effect of swainsonine could collaborate in the adverse effects observed in the fetus. The teratogenic effects of exposure to the toxic principles of I. carnea were evaluated not only using the conventional protocol but also at later stages in the postnatal developmental period. Females were treated, from gestation day (GD) 6 until GD19, with 0.0, 1.0, 3.0 or 7.0 g/kg body weight of I. carnea dry leaves. The plant did not induce changes in reproductive performance or biochemical profile of the dams. Dams that received the highest dose of I. carnea showed cytoplasmic vacuolization in the liver, kidney and placental tissue. I. carnea promoted different lectin binding patterns in different areas of placental tissue. No fetal skeletal or visceral malformations was observed. The postnatal evaluation revealed a lower litter weight and a lower pup body weight one day after birth in the group that received the highest dose of I. carnea. Physical milestones were unaffected by the treatments. Female pups from all experimental groups exhibited a delay in achieving a negative geotaxis response. The results show that the toxic principle of I. carnea produces injury in utero in mothers and fetuses, but these deleterious effects were better demonstrated using postnatal evaluation.

    Palavras-Chave: toxicity; plants; reproduction; placenta; fetuses; teratogens; alkaloids; bioassay; tropical regions

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  • IPEN-DOC 27733

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O. do; CALDAS, LINDA V.E. . New Fricke Xylenol Liquid detector doped with methylene blue (FXL-mblue) irradiated with red LED light. Journal of Luminescence, v. 230, p. 1-9, 2021. DOI: 10.1016/j.jlumin.2020.117730

    Abstract: In photodynamic therapy, a beam of incident light on the target causes interactions with the photosensitizing agent in the patient, subsequently killing cancerous cells through chemical and biological processes. The objective of this work was to describe for the first time the use of the FXL-mblue detector in dosimetric applications with irradiations from red LED light and using the UV–Vis spectrophotometry as an evaluation technique. The FXL-mblue samples were irradiated with doses of 2.40 kJ/cm2 up to 21.6 kJ/cm2 using a red LED light system. The results showed good results on uncertainties, sensitivity, reproducibility, repeatability, minimum detectable dose (MDD) and fading times for a promising dosimeter in measurements with visible light. In conclusion, the results indicate good dosimetric characteristics which could be used in quality control of photodynamic therapy measurements.

    Palavras-Chave: chemical dosemeters; dosemeters; xylenols; methylene blue; light emitting diodes; ultraviolet spectrometers; therapy; photosensitivity

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  • IPEN-DOC 27732

    GONCALVES, JOSEMARY A.C. ; MANGIAROTTI, ALESSIO; ASFORA, VIVIANE K.; KHOURY, HELEN J.; BUENO, CARMEN C. . The response of low-cost photodiodes for dosimetry in electron beam processing. Radiation Physics and Chemistry, v. 181, p. 1-8, 2021. DOI: 10.1016/j.radphyschem.2020.109335

    Abstract: The response of thin diodes (SFH206k) as dosimeters has been investigated employing the beam of an electron accelerator within the dose rate range of 2–8 kGy/s and accumulated doses up to 100 kGy. These devices, operating in the short-circuit mode and under industrial irradiation conditions, deliver current signals nonlinearly dependent on the dose rate, whichever the dose history of the diodes, due to the high density of the generated electron-hole pairs herein achieved. Despite this nonlinearity, the dose rate response is stable and characterized by current signals with repeatability better than 2.0%, regardless of the accumulated dose. It is also found that the dose responses are quite linear with sensitivities slightly dependent on the accumulated dose at a constant dose rate. The decrease in the charge sensitivity, taking as reference that obtained before any radiation damage, reaches only 9% (k = 2) at 100 kGy, which is much smaller than the values reported in the literature. From this low aging and the repeatability of both dose rate and dose responses, it seems that the photodiode under investigation is a low budget alternative, good enough for routine dosimetry, provided it has been previously calibrated in the same processing facility.

    Palavras-Chave: photodiodes; dosimetry; electron beams; dosemeters; electron dosimetry; si semiconductor detectors; dose rates

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  • IPEN-DOC 27731

    MENDES, BRUNO M.; ANTUNES, PAULA C.G. ; BRANCO, ISABELA S.L. ; NASCIMENTO, EDUARDO do; SENIWAL, BALJEET; FONSECA, TELMA C.F.; YORIYAZ, HELIO . Calculation of dose point kernel values for monoenergetic electrons and beta emitting radionuclides: intercomparison of Monte Carlo codes. Radiation Physics and Chemistry, v. 181, p. 1-8, 2021. DOI: 10.1016/j.radphyschem.2020.109327

    Abstract: Targeted radionuclide therapy (TRT) and beta-emitting seeds brachytherapy (BSBT) exploit the characteristics of energy deposited by beta-emitting radionuclides. Monte Carlo (MC) modelling of electron transport is crucial for calculations of absorbed dose for TRT and BSBT. However, computer codes capable of providing consistent results are still limited. Since experimental validations show several difficulties, the estimation of electron dose point kernel (DPK) is often used to verify the accuracy of different MC codes. In this work, we compared DPK calculations for various point, isotropic and monoenergetic electron sources and several beta-emitting radioisotopes using the codes MCNP, EGSnrc, PENELOPE and TOPAS with different simulation options. The simulations were performed using latest versions of EGSnrc and Penelope, TOPAS version 3.3.1 and MCNP version 6.1 Monte Carlo codes. In our simulations, the geometrical model consists of a point electron source placed at the center of a water sphere emitting isotropically. The water sphere was divided into 28 shells and the energy deposition was scored within these shells. The radius of the outermost shell was 1.2R0, where R0 is the continuous slowing down approximation (CSDA) range. Five monoenergetic beta sources with energies of 0.05, 0.1, 0.5, 1 and 3 MeV were studied. Six beta-emitting radionuclides were also simulated: Lu-177, Sm-153, Ho-166, Sr-89, I-131 and Y-90. Monoenergetic electron simulations showed large deviations among the codes, larger than 13% depending on the electron energy and the distance from the source. In the cases where beta spectra of radionuclides were simulated, all MC codes showed differences from EGSnrc (used as reference value - RV) less than 3% within rE90 range (radius of the sphere in which 90% of the energy of the spectrum electrons would be deposited). TOPAS showed results comparable to EGSnrc and PENELOPE. DPK values for 0.1 MeV monoenergetic electrons, calculated using MCNP6, led to differences higher than ±5% from RV despite our attempts to tune electron transport algorithms and physics parameters.

    Palavras-Chave: point kernels; computer calculations; computerized simulation; electron emission; electrons; beta particles; radionuclides; monte carlo method; therapy; brachytherapy

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  • IPEN-DOC 27730

    MANGIAROTTI, A.; PETRI, A.R.; MALAFRONTE, A.A.; GONCALVES, J.A.C. ; BARROS, S.F.; BUENO, C.C. ; FERNANDEZ-VAREA, J.M.; MAIDANA, N.L.; MARTINS, M.N.; VANIN, V.R.. A low-cost small-size commercial PIN photodiode: II. Comparison of measurements with monoenergetic electrons to analytical expressions and Monte Carlo simulations. Radiation Physics and Chemistry, v. 182, p. 1-20, 2021. DOI: 10.1016/j.radphyschem.2020.109102

    Abstract: Commercial PIN photodiodes, repurposed as particle detectors, have received a lot of attention along the past decades because they can offer a low-cost solution suitable for several applications. The BPX-65 photodiode has been chosen because of its interesting features for measuring electrons in a harsh radiation environment close to the beam of an accelerator. Its electrical characterisation and its application to photon spectrometry have been presented in the companion paper I. Here, its response function (RF) to electrons is investigated using the beam from an electron accelerator with a small energy spread. The empirical expressions for the RF available in the literature have been improved, simplified, and combined to obtain a final form with 7 free parameters: 4 non-linear and 3 linear. A special fitting procedure, which takes advantage of the presence of the linear parameters, is described. The behaviour of these parameters with beam energy and bias is investigated to uncover the physical origin of the three components included in the proposed RF. The interpretation of the features of the spectra is confirmed by Monte Carlo simulations carried out employing the general-purpose PENELOPE/penEasy package. To take into account the charge-collection properties of the device, a simple model has been implemented and is compared to data. It has then been possible to estimate the thickness of the partially dead layer from the experiment.

    Palavras-Chave: photodiodes; silicon; monte carlo method; plasma; experiment planning; response functions

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  • IPEN-DOC 27729

    RODRIGUES, FLAVIO T.; KOIKE, AMANDA C.R. ; SILVA, PAMELA G. da ; NEGRAO, BIANCA G. ; ALENCAR, SEVERINO M. de; MANCINI FILHO, JORGE; VILLAVICENCIO, ANNA L.C.H. . Effects of electron beam irradiation on the bioactive components of goji-berry. Radiation Physics and Chemistry, v. 179, p. 1-5, 2021. DOI: 10.1016/j.radphyschem.2020.109144

    Abstract: The goji-berry (Lycium barbarum) is an oval-shaped orange-red fruit with a slightly sweet flavor. This berry has a high antioxidant potential and presents interesting nutritional and therapeutic properties. Irradiation is a safe method that has long used to reduce the microbiological contamination of dried and dehydrated food products. This study aimed to evaluate the irradiation effects on the bioactive compounds of goji berries by irradiating samples with an electron beam at doses of 2.5, 5.0, 7.5, and 10.0 kGy. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and oxygen radical absorbance capacity (ORAC) were assessed by analyzing the hydroalcoholic extracts. The total phenolic compounds determined by the Folin-Ciocalteu assay. Doses up to 10.0 kGy did not significantly affect the antioxidant activity in the DPPH assay, and electron beam irradiation improved the total antioxidant activity of the samples in ORAC, as well as a total flavonoid and phenolics assays.

    Palavras-Chave: electron beams; irradiation; fruits; ionizing radiations; food additives; antioxidants; food processing; safety; food industry

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  • IPEN-DOC 27728

    BERBEL, GLAUCIA B.B.; HORTELLANI, MARCOS A. ; SARKIS, JORGE E. de S. ; CHIOZZINI, VITOR G.; FAVARO, DEBORAH I.T. ; SUTTI, BRUNO O.; SAKAZAKI, NIXON C.; BRAGA, ELISABETE de S.. Emerging contaminants (Rh, Pd, and Pt) in surface sediments from a Brazilian subtropical estuary influenced by anthropogenic activities. Marine Pollution Bulletin, v. 163, p. 1-13, 2021. DOI: 10.1016/j.marpolbul.2020.111929

    Abstract: The concentrations of Platinum (Pt), Rhodium (Rh) and Palladium (Pd) were evaluated from a highly impacted estuary in Brazil influenced by industrial pole, highway traffic and sewage outfall. The Santos-São Vicente region presents important economic activities derived from a largest harbor of Latin America and an industrial pole surrounded by intensive highway traffic. Values of Rh varied from 0.08 to 1.7 ng g−1 with highest values at stations impacted by domestic waste. Pt ranged from 0.15 to 40.3 ng g−1 with highest concentrations located close to the ferryboat traffic. Pd levels varied from 1.05 to 22.0 ng g−1 with values >5 ng g−1 in 50% of the stations. The spatial distribution of PGEs was not always directly associated with muddy sediments, because high PGE levels found even in sandy sediments. Pollution indexes, including anthropogenic factor (AF), geoaccumulation index (Igeo), Enrichment factor (EF), and Pollution Load Index (PLI) were used for evaluating contaminant potential. Based on EF, Igeo, and PLI, 50% of samples of the sediments from Santos-São Vicente Estuarine System (SSV) were classified with significant to strong PGE contamination. All stations on the Santos Channel (SC), São Vicente Channel (SVC) and Bertioga Channel (BC) had AF higher than 80% in at least one of PGE elements, as showed in station 2A, which presented AF <50% for Rh and Pd and 86% for Pt. Despite high anthropogenic enrichment, no correlations among PGE elements were observed in surface sediments. Only two stations presented Pd/Pt, Pt/Rh, and Pd/Rh typical ratios of auto catalyst (st. 14 and Piaçaguera) both located in the vicinity of highways. This could be due to the PGE deposition process in road dust, soil, and water as well as the biogeochemical cycling of PGEs involving organic metallic and inorganic complexes formed in the estuarine and seawaters.

    Palavras-Chave: estuaries; sediments; indexes; environment; coastal regions; water pollution; coastal waters; platinum; rhodium; palladium; chemical composition

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  • IPEN-DOC 27727

    OLIVEIRA, MARIA J.A. de ; VILLEGAS, GETHZEMANI M.E.; MOTTA, FLAVIA D.; FABELA-SANCHEZ, OMAR; ESPINOSA-ROA, ARIAN; FOTORAN, WESLEY L.; PEIXOTO, JANAINA C.; TANO, FABIA T.; LUGAO, ADEMAR B. ; VASQUEZ, PABLO A.S. . Influence of gamma radiation on Amphotericin B incorporated in PVP hydrogel as an alternative treatment for cutaneous leishmaniosis. Acta Tropica, v. 215, p. 1-8, 2021. DOI: 10.1016/j.actatropica.2020.105805

    Abstract: Amphotericin B (Amph-B) is an antifungal drug used intravenously for the treatment of leishmaniasis. Side-effects from Amph-B treatment can arise such as cardiac arrhythmia and renal dysfunctions, which will lead to discontinuation of treatment. Unfortunately, patients in endemic countries do not have access to alternative therapies. The objective of this study was to analyze the effects of Cobalt-60 gamma irradiation on crosslinking polymeric hydrogels (Hydg) and the incorporation of Amph-B into the gel as a controlled-release drug delivery alternative. Polyvinylpyrrolidone (PVP)/Amph-B solutions were irradiated with 15 kGy at 0 °C and 25 °C. The drug's stability was ascertained by UV–visible spectrometry, liquid chromatography/mass spectrometry and proton nuclear magnetic resonance. Irradiated Hydg/Amph-B achieved similar stability to the standard Amph-B solution and was enough to promote hydrogel crosslinking. In vitro trials were carried out to ensure Amph-B was still biologically active after irradiation. The results from flow cytometry and MTT assay show that Amph-B had an IC50 = 16.7 nM. A combination of Hydg at 1.324 gmL−1 and Amph-B at 25.1 nM for 24 h lead to the greatest inhibition of L. amazonensis promastigotes, and could be used as an alternative treatment method for cutaneous leishmaniosis.

    Palavras-Chave: antimicrobial agents; gamma radiation; hydrogels; drugs; delivery; parasitic diseases; irradiation

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  • IPEN-DOC 27724

    OLIVA, AMAURY M.; ALVES FILHO, HERMES; HERNANDEZ, CARLOS R.G.; MORAES, LEONARDO R. da C.. Método Espectral Determinístico para problemas de transporte de nêutrons na formulação SN, multigrupo de energia, geometria unidimensional, espalhamento anisotrópico e fonte fixa / The multigroup Spectral Deterministic Method for SN neutron transport theory in slab geometry, anisotropic scattering with fixed-source problems. Revista Cereus, v. 12, n. 2, p. 277-291, 2020. DOI: 10.18605/2175-7275/cereus.v12n2p277-291

    Abstract: Neste artigo é apresentada uma nova metodologia numérica contemplando o desenvolvimento de um método da classe dos espectro-nodais (malha grossa) para a solução de problemas de transporte de nêutrons na formulação das ordenadas discretas (𝑆𝑁), em geometria unidimensional, considerando o espalhamento anisotrópico, fonte fixa e multigrupo de energia. O método, denominado Método Espectral Determinístico (MED), baseia-se, inicialmente, na análise espectral das equações de transporte de nêutrons 𝑆𝑁. As incógnitas dessa metodologia são os fluxos angulares nos contornos e o fluxo angular médio no interior dos nodos espaciais. Os valores numéricos obtidos para essas grandezas, a menos dos erros da aritmética finita computacional, concordam com a solução analítica da equação de transporte 𝑆𝑁 no domínio espacial utilizado. Os resultados numéricos são mostrados e comparados com o tradicional método de malha fina, DD,cf., Diamond Difference e os métodos nodais SGF, cf., spectral Green’s function e o método FN para ilustrar a precisão numérica nos resultados obtidos pelo MED.

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  • IPEN-DOC 27723

    TORRES, WALMIR M. ; UMBEHAUN, PEDRO E. ; MATTAR NETO, MIGUEL ; BELCHIOR JUNIOR, ANTONIO ; FREITAS, ROBERTO L. . RMB experimental program on the hydrodynamical behavior of fuel assemblies. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-12, 2020. DOI: 10.15392/bjrs.v8i3A.1555

    Abstract: The Brazilian Multipurpose Reactor - RMB is a 30 MW pool type research reactor, that uses Materials Testing Reactor - MTR type fuel assemblies. It has a 5x5 square array core with 23 fuel assemblies and two in-core irradiation positions, operating with upward flow and average velocities nearly 10 m/s in the fuel plates channels. The IEA-R1 is a 5 MW pool type research reactor, which also has a 5x5 square array core with 19 standard fuel assemblies, four control fuel assemblies and a central beryllium irradiation device. It operates with downward flow nearly 1.8 m/s in the channels. In order to verify and provide data and information about the dynamical behavior of fuel assemblies under nominal and critical conditions, the experimental circuit ORQUÍDEA is being designed. This circuit will permit upward and downward flow and dynamical behavior of the fuel assemblies and its parts will be tested and verified. Flow rate, temperature, pressure and differential pressure transducers are the instruments of the circuit. Endurance and critical flow velocity tests will be performed. The COLIBRI experimental circuit is being designed to make tests that allow the studies of the fluid-structure phenomenology of fuel plates similar to those of the RMB fuel assemblies when subjected to high flow velocities, which can induce pressure differences between the channels formed by the fuel plates. This work presents a preliminary design for the ORQUÍDEA and COLIBRI experimental circuits to be built at the Instituto de Pesquisas Energéticas e Nucleares - IPEN of the Comissão Nacional de Energia Nuclear - CNEN.

    Palavras-Chave: comparative evaluations; computerized simulation; critical flow; critical velocity; experimental data; finite element method; flow rate; fuel assemblies; fuel plates; hydrodynamics; pressure range mega pa 10-100; rmb reactor; temperature range 0065-0273 k; temperature range 0400-1000 k

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  • IPEN-DOC 27722

    GABE, CESAR A.; FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . Modeling dynamic scenarios for safety, reliability, availability, and maintainability analysis. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-11, 2020. DOI: 10.15392/bjrs.v8i3A.1464

    Abstract: Safety analysis uses probability combinatorial models like fault tree and/or event tree. Such methods have static basic events and do not consider complex scenarios of dynamic reliability, leading to conservative results. Reliability, availability, and maintainability (RAM) analysis using reliability block diagram (RBD) experience the same limitations. Continuous Markov chains model dynamic reliability scenarios but suffer from other limitations like states explosion and restriction of exponential life distribution only. Markov Regenerative Stochastic Petri Nets oblige complex mathematical formalism and still subject to state explosions for large systems. In the design of complex systems, distinct teams make safety and RAM analyses, each one adopting tools better fitting their own needs. Teams using different tools turns obscure the detection of problems and their correction is even harder. This work aims to improve design quality, reduce design conservatism, and ensure consistency by proposing a single and powerful tool to perform any probabilistic analysis. The suggested tool is the Stochastic Colored class of Petri Nets, which supplies hierarchical organization, a set of options for life distributions, dynamic reliability scenarios and simple and easy construction for large systems. This work also proposes more quality rules to assure model consistency. Such method for probabilistic analysis may have the effect of shifting systems design from “redundancy, segregation and independency” approach to “maintainability, maintenance and contingency procedures” approach. By modeling complex human and automated interventional scenarios, this method reduces capital costs and keeps safety and availability of systems.

    Palavras-Chave: availability; computerized simulation; dynamical systems; maintenance; probabilistic estimation; redundancy; reliability; safety analysis; sensitivity analysis; stochastic processes

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  • IPEN-DOC 27721

    NIELSEN, G.F. ; MORAIS, N.W.S. ; LIMA, N.B. . Crystallographic texture of hot rolled uranium-molybdenum alloys. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-14, 2020. DOI: 10.15392/bjrs.v8i3A.1406

    Abstract: The uranium molybdenum (U-Mo) alloys have the potential to be used as low enriched uranium nuclear fuel in research, test, and power nuclear reactors. U-Mo alloy with composition between 7 and 10 wt% molybdenum shows excellent body centered cubic phase (γ phase) stabilization and presents a good nuclear fuel testing performance. Hot rolling is commonly utilized to produce nuclear fuel plate where it promotes the cladding and the fuel alloy bonding. The mechanical deformation generates crystallographic preferential orientation, the texture, which influences the material properties. This work studied the texture evolution in hot rolled U-Mo alloys. The U7.4Mo and U9.5Mo alloys were melted in a vacuum induction furnace, homogenized at 1000°C for 5 h, and then hot rolled at 650°C in three height reductions: 50, 65 and 80%. The crystalline phases and the texture were evaluated by X-ray diffraction (XRD). The as-cast and processed alloys microstructures were characterized by optical and electronic microscopies. The as-cast, homogenized, and deformed alloys have the γ phase. It was found microstructural differences between the U7.4Mo and U9.5Mo alloys. The homogenized treatment showed effective for microsegregation reduction and was not observed substantial grain size increasing. The deformed uranium molybdenum alloys presented α, γ, θ texture fibers. The intensity of these texture fibers changes with rolling reduction.

    Palavras-Chave: chemical composition; crystal structure; deformation; microstructure; molybdenum alloys; nuclear fuels; optical microscopy; rolling; scanning electron microscopy; texture; uranium alloys; x-ray diffraction

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  • IPEN-DOC 27720

    SMITH, RICARDO B. ; SACHDEVA, MAHIMA; BISURI, INDRANIL; VICENTE, ROBERTO . Advanced heavy water reactor: a new step toward sustainability. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-18, 2020. DOI: 10.15392/bjrs.v8i3A.1368

    Abstract: One of the great advances in the current evolution of nuclear power reactors is occurring in India, with the Advanced Heavy Water Reactor (AHWR). It is a reactor that uses thorium as part of its fuel, which in its two fueling cycle options, in conjunction with plutonium or low enriched uranium, produces energy at the commercial level, generating less actinides of long half-life and inert thorium oxide, which leads to an optimization in the proportion of energy produced versus the production of burnt fuels of the order of up to 50%. The objective of this work is to present the most recent research and projects in progress in India, and how the expected results should be in compliance with the current sustainability models and programs, especially the "Green Chemistry", a program developed since the 1990s in the United States and England, which defines sustainable choices in its twelve principles and that can also be mostly related to the nuclear field. Nevertheless, in Brazil, for more than 40 years there has been the discontinuation of research for a thorium-fueled reactor, and so far there has been no prospect of future projects. The AHWR is an important example as an alternative way of producing energy in Brazil, as the country has the second largest reserve of thorium on the planet.

    Palavras-Chave: fuel element clusters; hwlwr type reactors; nuclear fuels; radioactive wastes; reactor design; sustainable development; thorium; india

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  • IPEN-DOC 27719

    SMITH, R.B. ; SALVETTI, T.C. ; TESSARO, A.P.G. ; MARUMO, J.T. ; VICENTE, R.V. . Knowledge management in the decommissioning of nuclear facilities in Brazil. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-15, 2020. DOI: 10.15392/bjrs.v8i3A.1315

    Abstract: In the second half of the twentieth century in Brazil, several nuclear facilities were built for the most varied objectives. The largest number of such facilities is at the Nuclear and Energy Research Institute in São Paulo (IPEN-CNEN/SP). For different reasons, some of these facilities had their projects finalized and were deactivated. Some of the equipment was then dismantled, but the respective nuclear and radioactive material remained isolated in the original sites waiting for the proper decommissioning procedures. The Celeste Project is an example of a facility where the nuclear material has been kept, and is subject to Argentine-Brazilian Agency for Accounting and Control of Nuclear Materials (ABACC) periodic inspections. Because of a number of interests, including financial and/or budgeting situations at the institutions, decades have passed without any further action; the people who originally worked there, and possessed information and knowledge about these facilities, have already moved away from the area, or are in the process of. Therefore, because of the absence of knowledge management techniques in force at the time of establishing and operating these installations, this work proposes an analysis about the possible consequences in case of loss of perhaps the only one remaining knowledge, the one from the people who designed those departments and worked there.

    Palavras-Chave: decommissioning; historical aspects; information dissemination; information needs; knowledge management; nuclear facilities; radioactive materials; radioactive waste management; safety; brazilian cnen

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  • IPEN-DOC 27718

    PUGLIESI, R. ; STANOJEV PEREIRA, M.A. ; ANDRADE, M.L. . Concentration and distribution of oil in the reservoir mineral Dolomite studied by neutron tomography. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-12, 2020. DOI: 10.15392/bjrs.v8i3A.1291

    Abstract: Neutron Tomography – NT is a non-destructive technique, ideal for imaging hydrogen-rich substances even when wrapped up by thick rock layers. In the present study, the NT was employed for investigating the oil concentration and distribution in the mineral Dolomite, a natural oil reservoir. Two types of Dolomite samples, one of which dry, and the second one in oil-saturated were prepared. The applied oil was EMCAplus® 070 usually employed in permeability experiments to reproduce conditions of natural oil reservoirs. Three small fragments of the dry sample and three of the oil sample were inspected by NT and the comparison between the obtained results enabled, to distinguish several regions in which the oil is stored, to indicate that the oil is dispersed throughout the volume of the samples, and to quantify the storage concentration. The obtained data for oil concentration, for the three fragments, were compared to each other and to the one obtained by the conventional gravimetric technique, and they agreed within their uncertainties, demonstrating the viability of the NT technique to inspect, either in a qualitative as in a quantitative level, this oil reservoir mineral.

    Palavras-Chave: concentration ratio; distribution; dolomite; neutrons; petroleum; petroleum deposits; prospecting; scanning electron microscopy; tomography

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  • IPEN-DOC 27717

    CURBELO, J.P.; LIBOTTE, R.B.; OLIVA, A.M.; BARROS, R.C.; ALVES FILHO, H.. The modified spectral deterministic method applied to fixed–source discrete ordinates problems in X, Y–geometry. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-14, 2020. DOI: 10.15392/bjrs.v8i3A.1268

    Abstract: A new approach for the application of the coarse–mesh Modified Spectral Deterministic method to numerically solve the two–dimensional neutron transport equation in the discrete ordinates (𝑺𝑵) formulation is presented in this work. The method is based on within node general solution of the conventional one–dimensional 𝑺𝑵 transverse integrated equations considering constant approximations for the transverse leakage terms and obtaining the 𝑺𝑵 spatial balance equations. The discretized equations are solved by using a modified Source Iteration scheme without additional approximations since the average angular fluxes are computed analytically in each iteration. The numerical algorithm of the method presented here is algebraically simpler than other spectral nodal methods in the literature for the type of problems we have considered. Numerical results to two typical model problems are presented to test the accuracy of the offered method.

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  • IPEN-DOC 27716

    FIGUEIREDO, C.D.R. ; MATTAR NETO, M. . Recommendation for linearization procedure in nuclear pressure vessel-nozzle intersections. Brazilian Journal of Radiation Sciences, v. 8, n. 3A, p. 1-13, 2020. DOI: 10.15392/bjrs.v8i3A.1572

    Abstract: The pressure vessel design is a fundamental step during the construction of new pressurized water reactors (PWRs). In these facilities, several safety requirements are necessary to guarantee the protection of workers, community and environment against the release of radioactive materials. The Design by Analysis is the procedure presented in the ASME Code, Section III, for nuclear components, which consist of rigorous analysis and classification of all types of stresses and loading conditions to incorporate smaller safety factors increasing the general safety. The limits presented in the ASME Code, Section III, were based on the shell theory. However, precise rules for achieving the various stress categories, in solid finite element analysis, have not been implemented yet in the code. For this reason, this work presents a methodology for the linearization procedure of elastic stresses in pressure vessel-nozzle intersections. Therefore, a vessel was modelled in tridimensional solid finite elements, analyzed and verified as a nuclear component. Then, a discussion of how to perform the code verifications was presented, as well as a mapping of stresses. The lines that were constructed in pressure vessel between transition and structural elements in the longitudinal plane (0º) and lines in structural elements in the nozzle in the transversal plane (90º) present higher stresses and are compared with the ASME Code, Section III limits.

    Palavras-Chave: a codes; design; finite element method; mesh generation; nozzles; pressure vessels; pwr type reactors; stress analysis

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  • IPEN-DOC 27715

    BUSTILLOS, OSCAR V. . Mobilidade iônica acoplada a espectrometria de massas. Revista Analytica, v. 111, p. 21-23, 2021.

    Palavras-Chave: mass spectroscopy; ion mobility; electron capture; electron detection; isomers; drugs

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  • IPEN-DOC 27714

    BUSTILLOS, OSCAR V. . O espectro de massas na espectrometria de massas. Revista Analytica, v. 110, p. 24-26, 2021.

    Palavras-Chave: mass spectra; mass spectroscopy; ion sources; chemical analysis; electron scanning; ionization

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  • IPEN-DOC 27713

    LIMA, VERA M.F. de ; PEREIRA JUNIOR, ALFREDO; OLIVEIRA, GUILHERME L. de. The spreading depression propagation: how electrochemical patterns distort or create perception. Open Journal of Biophysics, v. 11, n. 2, p. 133-146, 2021. DOI: 10.4236/ojbiphy.2021.112003

    Abstract: At the transition from quiescence to propagating waves recorded in isolated retinas, a circular electric current closes in the extracellular matrix; this circular current creates a magnetic torus flow that, when entering quiescent tissue in front of the wave, recruits elements and when leaving behind, helps to build the absolute refractory state. The waving magnetic torus is the consequence of the vortex effect and explains the energy boost that drives propagation. Methods: We interpret experimental results from intrinsic and extrinsic fluorescence dyes, voltage, calcium and pH sensitive, optical signals from isolated retinas, and time series recordings using ion exchange resins: Ca, K, pH, Na, Cl recorded extracellularly at retinas, cerebellums and cortices coupled to spreading depression waves. Finally, we checked the ECoG activity, also a time series, at the transition from after discharges to spreading depression in rat hippocampus. Results: The integrated assessment of the diversified measurements led to the realization that the magnetic flow at the wavefront is a major contributor to the wave propagation mechanisms. This flow couples mass and charge flows as a swirling torus from excited to quiescent tissue. Conclusions: An alternative model of the brain is possible, apart from the classical HH and molecular biology model. Physical chemistry of charged gels and its flows explains the results. The conceptual framework uses far from equilibrium thermodynamics.

    Palavras-Chave: brain; electrochemistry; retina; resonance; central nervous system; vortices; vortex flow

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  • IPEN-DOC 27712

    KLUMPP, RAFAEL E. ; DONATUS, UYIME ; SILVA, REJANE M.P. da ; ANTUNES, RENATO A.; MACHADO, CARULINE de S.C. ; MILAGRE, MARIANA X. ; ARAUJO, JOAO V. de S. ; VIVEIROS, BARBARA V.G. de ; COSTA, ISOLDA . Corrosion protection of the AA2198-T8 alloy by environmentally friendly organic-inorganic sol-gel coating based on bis-1,2-(triethoxysilyl) ethane. Surface and Interface Analysis, v. 53, n. 3, p. 314-329, 2021. DOI: 10.1002/sia.6919

    Abstract: In this work, a surface coating composed of organic‐inorganic hybrid sol‐gel based on bis‐1,2‐(triethoxysilyl) (BTSE) ethane was applied on AA2198‐T8 samples, and its effect on corrosion resistance was investigated and compared with that of a chromate layer formed in a solution with hexavalent chromium ions. The corrosion resistance of BTSE coated samples was evaluated by immersion tests in sodium chloride solution (0.005 mol/L NaCl) and monitored by global electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and local electrochemical techniques such as scanning vibrating electrode technique (SVET) and scanning electrochemical microscopy (SECM). The formed coating layers were characterized by X‐ray photoelectron spectroscopy (XPS). The results pointed out that the BTSE is an effective alternative coating for corrosion protection of new generation Al‐Cu‐Li alloys and could replace chromates obtained in toxic and carcinogenic CrVI containing solutions leading to improved corrosion protection.

    Palavras-Chave: corrosion; corrosion protection; surface coating; silanes; aluminium alloys; sol-gel process; hybrid systems; corrosion resistance

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  • IPEN-DOC 27711

    NUNES, MARIO A.B.S.; MATOS, BRUNO R. de ; SILVA, GLAURA G.; ITO, EDSON N.; MELO, TOMAS J.A. de; FECHINE, GUILHERMINO J.M.. Hybrids nanocomposites based on a polymer blend (linear low-density polyethylene/poly(ethylene-co-methyl acrylate) and carbonaceous fillers (graphene and carbon nanotube). Polymer Composites, v. 42, n. 2, p. 661-677, 2021. DOI: 10.1002/pc.25856

    Abstract: Interfacial or separate phase location of carbonaceous nanofillers (graphene and carbon nanotubes) in polymer blends with co-continuous phases can lead to double percolation behavior, significantly increasing rheological and electrical properties. The prediction of the morphology and the location of the nanofillers has been used as a tool to evaluate the proprieties of co-continuous polymer blends. This work aims to highlight the superior conductivity levels achieved using a low amount of carbon-based fillers, by the proper selection in a multiphase polymer matrix as a template for controlled dispersion and spatial distribution of the nanoparticles, offering a compromise between easy processability and enhanced performance. Here, two polymers (linear low-density polyethylene [LLDPE] and ethylene-co-methylacrylate [EMA]) and their cocontinuous blend (LLDPE/EMA) were loaded with nanofillers (few-layer graphene [FLG], few-walled carbon nanotube [FWCNT]) via continuous melt mixing in twin-screw extrusion, separate and simultaneously. It was observed that the addition of the nanofillers changed the co-continuity of the blend, with the probable migration of the nanofillers from the EMA (hydrophilic) phase to the LLDPE (hydrophobic) phase. Rheological percolation occurred preferentially in blends containing FWCNT and FLG/FWCNT. Electrical conductivity was observed in all compositions, with higher electrical conductivity being noticed in hybrids.

    Palavras-Chave: nanocomposites; hybridization; nanotechnology; polyethylenes; polymers; electric conductivity; carbon nanotubes; graphene

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  • IPEN-DOC 27710

    ZANINI, NATHALIA A. ; RABELO, THAIS F. ; ZAMATARO, CLAUDIA B. ; CARAMEL-JUVINO, AMANDA ; ANA, PATRICIA A.; ZEZELL, DENISE M. . Morphological, optical, and elemental analysis of dental enamel after debonding laminate veneer with Er,Cr:YSGG laser: a pilot study. Microscopy Research and Technique, v. 84, n. 3, p. 489-498, 2021. DOI: 10.1002/jemt.23605

    Abstract: Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty‐four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 μm) using two different protocols:3.5 W, 48.14 J/cm2, 20 Hz non‐contact and 3.0 W, 48.14 J/cm2, 20 Hz non‐contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy‐dispersive X‐ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.

    Palavras-Chave: dentistry; enamels; lasers; laser radiation; lithium; tomography; optical properties; coherent radiation; teeth

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  • IPEN-DOC 27709

    GODOI, C.M. ; SANTOS, M.C.L. ; SILVA, A.J. ; TAGOMORI, T.L.; RAMOS, A.S. ; SOUZA, R.F.B. de ; OLIVEIRA NETO, A. . Methane conversion to higher value‑added product and energy co‑generation using anodes OF PdCu/C in a solid electrolyte reactor: alkaline fuel cell type monitored by differential mass spectroscopy. Research on Chemical Intermediates, v. 47, n. 2, p. 743-757, 2021. DOI: 10.1007/s11164-020-04296-4

    Abstract: PdxCuy/C catalysts combinations were employed to CH4 partial oxidation in mild condition using a solid electrolyte reactor—alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor the oxidation products obtained as methanol, dimethyl ether, methyl formate and potassium formate. It was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for conversion of methane into methanol and energy co-generation was obtained from Pd90Cu10/ C and Pd50Cu50/ C due to better H2O activation effects and adsorption site for CH4 oxidation.

    Palavras-Chave: methane; electrocatalysts; solid electrolytes; oxidation; methanol; fourier transformation; infrared spectra; mass spectroscopy

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  • IPEN-DOC 27708

    LOPES, MONICA S.; PEREIRA, DAISA L. ; MOTA, CLAUDIA C.B. de O.; AMARAL, MARCELLO M.; ZEZELL, DENISE M. ; GOMES, ANDERSON S.L.. The lingual enamel morphology and bracket shear bond strength influenced by Nd:YAG laser and aluminum oxide sandblasting preconditioning. Clinical Oral Investigations, v. 25, n. 3, p. 1151-1158, 2021. DOI: 10.1007/s00784-020-03418-x

    Abstract: Objectives This study aimed to investigate the influence of Nd:YAG laser and aluminum oxide sandblasting on the shear bond strength (SBS) of lingual brackets and to optically analyze the behavior of the enamel morphology. Materials and methods Thirty-five bovines’ incisors teeth were divided into 5 groups (n = 7), according to the surface preconditioning: G1, control group; G2, Nd:YAG laser; G3, laser + aluminum oxide sandblasting (Al2O3); G4, Al2O3; and G5, Al2O3 + laser. All groups had lingual brackets bonded and shear debonded after 72 h. SBS values were analyzed, and the enamel morphology was evaluated by optical coherence tomography (OCT) and scanning electron microscope (SEM), before and after preconditioning surface. The optical attenuation coefficient (α) analysis was obtained from OCT images. Data analysis used the ANOVA test, followed by post hoc Tukey, Kruskal Wallis, and post hoc Dunn tests (significance of 5%). Results The SBS values presented similarly among groups, but the value of α showed statistical difference (p-value = 0.0124) between G3 and G5 with the others. Optical analyses indicated a melting on the enamel that suffered laser irradiation for G2 and G5 and crystal surface disorganization for G4. Sandblasting partially removes the melting of the laser effect (G3). Conclusion The sandblasting is a dispensable step for bonding lingual brackets, and the melting of the enamel after laser irradiation does not compromise the bracket adhesive resistance. Clinical relevance The Nd:YAG laser became an interesting tool to prevent caries and decrease prevalence of white spot lesions in orthodontic treatments, without systemic effects in patients with genetic high risks of caries.

    Palavras-Chave: dentistry; lasers; teeth; enamels; aluminium oxides; oral cavity; tongue; tomography

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  • IPEN-DOC 27707

    AZEVEDO, LUCIANA C. de ; ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; DIAS, DJALMA B. ; NASCIMENTO, SANDI S.; OLIVEIRA, FABIO F.; SILVA, LEONARDO G.A. ; FUNGARO, DENISE A. . Study of renewable silica powder influence in the preparation of bioplastics from corn and potato starch. Journal of Polymers and the Environment, v. 29, n. 3, p. 707-720, 2021. DOI: 10.1007/s10924-020-01911-8

    Abstract: In the present study, 0.5–1.5% silica powder, from sugarcane waste ash, was incorporated into corn and potato starch bioplastics doped with sodium silicate solution to improve the properties of elongation at break and increase the thermal resistance of the bioplastics. The starch-based bioplastics were produced by casting and characterized by color analyses, transparency, opacity apparent, humidity, thickness, tensile strength, elongation at break, FTIR, DSC, SEM, and biodegradation assay. The addition of 0.5% of silica powder improved the elongation at break of the corn starch-based bioplastics. The sample CS5-P0.5 presented the highest percentage of elongation at the break among the studied samples, increased from 59.2% (without silica powder) to 78.9% (with silica powder). For potato starch bioplastic the addition of 0.5% of silica powder did not improve elongation at break but increased the thermal resistance. Increased until 17 °C for PS5-P0.5 sample and until 11 °C for PS7.5-P0.5 sample. The bioplastics of potato starch were biodegraded in 5 days, and those of corn starch took almost 40 days. Silica powder inhibited the growth of fungi in starch bioplastics.

    Palavras-Chave: silica; powders; temperature dependence; thermal conductivity; sugar cane; ashes; silica; biodegradation; plastics

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  • IPEN-DOC 27706

    ASSIS, GABRIEL P.; GARCIA, RAFAEL H.L. ; DERENZO, SILAS; BERNARDO, ANDRE. Solid-liquid equilibrium of paracetamol in water-ethanol and water-propylene glycol mixtures. Journal of Molecular Liquids, v. 323, p. 1-13, 2021. DOI: 10.1016/j.molliq.2020.114617

    Abstract: Solubility is one of most important property to produce active pharmaceutical ingredients (APIs), beyond of being related to its bioavailability. In this context, itwas determined paracetamol solid-liquid equilibriumin temperatures from20 to 50 °C for two solvent systems:water - ethanol andwater - propylene glycol (PG), by refractometry method. The experimental results were compared with five thermodynamic models (Apelblat,Wilson, UNIQUAC, NRTL and λh) and data from the literature, showing good correlations for Apelblat and the best predictive fit for the NRTL model in both solvent mixtures. Maximum solubility values were observed in a 75% ethanol composition, this result being unusual and not the same with PG. the results of this work were compared with the literature and some references point to similar behavior. Optical microscopy and X-ray diffractionmeasurements of the solids in equilibrium with the liquid indicate that maximum solubility is not associated with a change in the crystalline structure of the solid

    Palavras-Chave: chemical preparation; drugs; solubility; ethanol; propylene; glycols; x-ray diffraction; thermodynamics

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  • IPEN-DOC 27705

    SILVA, ROSANA V. da; VOLTZ, HIURY; ITMAN FILHO, ANDRE; MILAGRE, MARIANA X. ; MACHADO, CARULINE de S.C. . Hybrid composites with glass fiber and natural fibers of sisal, coir, and luffa sponge. Journal of Composite Materials, v. 55, n. 5, p. 717-728, 2021. DOI: 10.1177/0021998320957725

    Abstract: Hybrid composites with synthetic and natural fibers are a good choice in the field of composites, as they combine the good mechanical performance of synthetic fibers with the advantages of natural fibers. In this work, polymeric hybrid composites associating glass fiber and natural fibers were developed. Three hybrid composites were developed: sisal/ glass, coir/glass and Luffa/glass. The composites are five-layer laminate, three layers of E-glass interspersed with two layers of natural fibers that can be sisal, coir, or Luffa sponge (Luffa Cylindrica). In addition to hybrid composites, a five-layer fiberglass composite was also manufactured. The composites were manufactured by compression molding technique using orthophthalic polyester resin as matrix. Tensile and flexural tests were performed to characterize the composites. Considering the three hybrid composites, the best behavior was observed for the sisal/glass composite, being a potential replacement for fiberglass. The order of performance was the same in the tensile and flexural tests, sisal/glass, coir/glass, and luffa/glass, in this order. In the specimen’s fracture analysis, for both tests, it was observed that the fracture was quite located with no damage in regions far from the fracture. This behavior indicates good adhesion between the layers of natural and synthetic fibers, despite the discrepancy of their properties.

    Palavras-Chave: hybridization; composite materials; fibers; coconuts; microstructure; fiberglass

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  • IPEN-DOC 27704

    OLIVEIRA, DANIEL C.F. dos S.; MONTILLA-ROSERO, ELENA; LOPES, FABIO J. da S. ; MORAIS, FERNANDO G. ; LANDULFO, EDUARDO ; HOELZEMANN, JUDITH J.. Aerosol properties in the atmosphere of Natal/Brazil measured by an AERONET Sun-photometer. Environmental Science and Pollution Research, v. 28, n. 8, p. 9806-9823, 2021. DOI: 10.1007/s11356-020-11373-z

    Abstract: We analyzed data measured by a Sun-photometer of the RIMA-AERONET network with the purpose to characterize the aerosol properties in the atmosphere over Natal, state capital of Rio Grande do Norte, at the coast of Northeast Brazil. Aerosol Optical Depth, Ångström Exponent, Volume Size Distribution, Single Scattering Albedo, Complex Refractive Index, Asymmetry Factor, and Precipitable Water were analyzed from August 2017 to March 2018. In addition, MODIS and CALIOP observations, local Lidar measurements, and modeled backward trajectories were analyzed in a case study on February 9, 2018, that consistently confirmed the identification of a persistent aerosol layer below 4 km agl. Aerosols present in the atmosphere of Natal showed monthly mean Aerosol Optical Depth at 500 nm below 0.15 (~ 75%), monthly means of the Ångström Exponent at 440–670 nm between 0.30 and 0.70 (~ 69%), bimodal Volume Size Distribution is dominantly coarse mode, Single Scattering Albedo at 440 nm is 0.80, Refractive Index - Real Part around 1.50, Refractive Index - Imaginary Part ranging from 0.01 to 0.04, and the Asymmetry Factor ranged from 0.73 to 0.80. The aerosol typing during the measurement period showed that atmospheric aerosol over Natal is mostly composed of mixed aerosol (58.10%), marine aerosol (34.80%), mineral dust (6.30%), and biomass burning aerosols (0.80%). Backward trajectories identified that 51% of the analyzed air masses over Natal originated from the African continent.

    Palavras-Chave: satellite atmospheres; sun; photometers; optical radar; optical systems; aerial monitoring; atmospheres; optical properties; dusts; environment; environmental impacts; physical properties; biomass; brazil; africa; climatic change

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  • IPEN-DOC 27703

    SENIWAL, BALJEET; FREITAS, LUCAS F. ; MENDES, BRUNO M.; LUGAO, ADEMAR B. ; KATTI, KATTESH V.; FONSECA, TELMA C.F.. In silico dosimetry of low-dose rate brachytherapy using radioactive nanoparticles. Physics in Medicine and Biology, v. 66, n. 4, p. 1-13, 2021. DOI: 10.1088/1361-6560/abd671

    Abstract: Purpose. Nanoparticles (NPs) with radioactive atoms incorporated within the structure of the NP or bound to its surface, functionalized with biomolecules are reported as an alternative to low-dose-rate seed-based brachytherapy. In this study, authors report a mathematical dosimetric study on low-dose rate brachytherapy using radioactive NPs. Method. Single-cell dosimetry was performed by calculating cellular S-values for spherical cell model using Au-198, Pd-103 and Sm-153 NPs. The cell survival and tumor volume versus time curves were calculated and compared to the experimental studies on radiotherapeutic efficiency of radioactive NPs published in the literature. Finally, the radiotherapeutic efficiency of Au-198, Pd-103 and Sm-153 NPs was tested for variable: administered radioactivity, tumor volume and tumor cell type. Result. At the cellular level Sm-153 presented the highest S-value, followed by Pd-103 and Au-198. The calculated cell survival and tumor volume curves match very well with the published experimental results. It was found that Au-198 and Sm-153 can effectively treat highly aggressive, large tumor volumes with low radioactivity. Conclusion. The accurate knowledge of uptake rate, washout rate of NPs, radio-sensitivity and tumor repopulation rate is important for the calculation of cell survival curves. Self-absorption of emitted radiation and dose enhancement due to AuNPs must be considered in the calculations. Selection of radionuclide for radioactive NP must consider size of tumor, repopulation rate and radiosensitivity of tumor cells. Au-198 NPs functionalized with Mangiferin are a suitable choice for treating large, radioresistant and rapidly growing tumors.

    Palavras-Chave: nanoparticles; radioactive materials; radioactivity; brachytherapy; dose rates; low dose irradiation; dosimetry; radiotherapy; nanomaterials; neoplasms

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  • IPEN-DOC 27702

    GUILHEN, SABINE N. ; ROVANI, SUZIMARA ; ARAUJO, LEANDRO G. de ; TENORIO, JORGE A.S.; MASEK, ONDREJ. Uranium removal from aqueous solution using macauba endocarp-derived biochar: effect of physical activation. Environmental Pollution, v. 272, p. 1-10, 2021. DOI: 10.1016/j.envpol.2020.116022

    Abstract: The main aim of this study was to evaluate options for addressing two pressing challenges related to environmental quality and circular economy stemming from wastage or underutilization of abundant biomass residue resources and contamination of water by industrial effluents. In this study we focused on residues (endocarp) from Macaúba palm (Acrocomia aculeata) used for oil production, its conversion to activated biochar, and its potential use in uranium (U) removal from aqueous solutions. Batch adsorption experiments showed a much higher uranyl ions (U(VI)) removal efficiency of activated biochar compared to untreated biochar. As a result of activation, an increase in removal efficiency from 80.5% (untreated biochar) to 99.2% (after activation) was observed for a 5 mg L 1 initial U(VI) concentration solution adjusted to pH 3 using a 10 g L 1 adsorbent dosage. The BET surface area increased from 0.83 to 643 m2 g 1 with activation. Surface topography of the activated biochar showed a very characteristic morphology with high porosity. Activation significantly affected chemical surface of the biochar. FTIR analysis indicated that U(VI) was removed by physisorption from the aqueous solution. The adsorbed U(VI) was detected by micro X-ray fluorescence technique. Adsorption isotherms were employed to represent the results of the U adsorption onto the activated biochar. An estimation of the best fit was performed by calculating different deviation equations, also called error functions. The Redlich-Peterson isotherm model was the most appropriate for fitting the experimental data, suggesting heterogeneity of adsorption sites with different affinities for uranium setting up as a hybrid adsorption. These results demonstrated that physical activation significantly increases the adsorption capacity of macauba endocarp-derived biochar for uranium in aqueous solutions, and therefore open up a potential new application for this type of waste-derived biochar.

    Palavras-Chave: aqueous solutions; vegetable oils; vegetables; coconuts; uranium; adsorption; chemical activation; activated carbon; charcoal

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  • IPEN-DOC 27688

    CIONE, FRANCISCO C. ; BETINI, EVANDRO G. ; BOATO, MARCOS G.; SOUZA, ARMANDO C. de; ROSSI, JESUALDO L. . Experimental analyses defining mechanical characteristics of obtained W-Cu-Ni composite applied as a radiation shielding material. International Review of Mechanical Engineering (IREME), v. 14, n. 3, p. 169-176, 2020. DOI: 10.15866/ireme.v14i3.17084

    Abstract: This work aims to obtain a new composite material of system W-Cu-Ni using the powder metallurgy usable as material for strongly shielding of the gamma radiation as an environmental friendly alternative to lead. Tungsten (W) is the main shielding element in this composite. The main reason to use CuNi in this compound is the miscibility of both metals and their low fusion temperature, allowing liquid phase sintering. The tungsten has high density (19.25 gcm-3), high melting point (3,422 °C) and is presented as matrix of the composite. In order to meet the need for sintering with low temperatures, the liquid phase sintering technique has been used. For sintering temperature optimization, the particles of the metal powders have been homogenized in shape and size. In order to reduce the average particles size, a ball mill has been used for 48 hours. After grinding, the particle size analysis has showed that the mean particle size in WCuNi composition has been 8.6 μm. The powder mixture has been compacted in isostatic press at 200 MPa pressure. The samples have been sintered between 1,100 °C and 1,400 °C at 1100 mbar pressure with a flow of protective atmosphere (Ar2) for 180 min for each temperature. The formation of the isomorphic system CuNi is responsible for giving the mechanical characteristic of solid to the composite WCuNi. The result of micro hardness test shows a maximum of 331 HV and average of 276 HV. Optical and electronic microscopy (SEM) with EDS have been undertaken in order to characterize the samples. The classical scientific method of experimentations with gamma radiation of the cobalt-60 source by attenuation of the energies has been employed to study these effects on the samples. The results shows that composite has more shielding efficient than lead and is safety for life and environment when compared with lead toxity.

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  • IPEN-DOC 27687

    LIMA, CAROLINE S.A. de; VARCA, GUSTAVO H.C. ; COSTA, SIRLENE M. da; FERRAZ, HUMBERTO G.; SANTOS, ANA C. da S.; LOPES, PATRICIA S.; COSTA, SILGIA A. da. Development of natural polymeric microcapsules for antimicrobial drug delivery: triclosan loaded chitosan and alginate-based microcapsules. Drug Development and Industrial Pharmacy, v. 46, n. 9, p. 1477-1486, 2020. DOI: 10.1080/03639045.2020.1809445

    Abstract: The goal of this work was the development of natural polymeric microcapsules for antimicrobial drug delivery – triclosan loaded alginate and chitosan-based microcapsules for potential coating applications in substrates such as textiles or plastics. Microcapsules containing 2.5% (w/w) or 3% (w/w) triclosan in both core and matrix were synthesized and evaluated by Fourier-transform infrared spectroscopy, scanning electron microscopy, confocal microscopy, differential scanning calorimetry, thermogravimetry, and antimicrobial activity. The microcapsules produced featured spherical and mostly irregularly-shaped surfaces composed by an alginate core in a chitosan outer matrix, as revealed by confocal microscopy, and antimicrobial activity against S. aureus and E. coli with inhibition halos up to 60 mm and 25 mm respectively, granted by a triclosan loading of 61.66%. The thermal analysis suggested that the polymers protected the active substance from temperature-induced degradation. In conclusion, these microcapsules may be applied toward antimicrobial functionalization of plastics, textiles and other materials.

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  • IPEN-DOC 27686

    ARAUJO, JOAO V. de S. ; SILVA, REJANE M.P. da ; MILAGRE, MARIANA X. ; MACHADO, CARULINE de S.C. ; COSTA, ISOLDA . Mecanismo de evolução de hidrogênio durante a corrosão da liga 2198-T8 em meio contendo cloreto: uma abordagem eletroquímica / On the hydrogen evolution mechanism during corrosion of the 2198-T8 alloy in chloride solution: an electrochemical approach. Química Nova, v. 43, n. 8, p. 1058-1065, 2020. DOI: 10.21577/0100-4042.20170598

    Abstract: Corrosion is still one of the most serious and frequent problems in industries. The phenomena involved in the corrosion mechanism of Al-alloys may be explained by formation of galvanic cells between the metal matrix and heterogeneities, such as precipitates, intermetallic phases leading to potential differences and electrochemical reactions. In the cathodic sites, the main reactions are oxygen reduction reaction, in aerated neutral environments, and hydrogen evolution in acid media. This last type of reaction might also occur in neutral solutions inside pits (anodic region). In this study, the mechanism of hydrogen evolution during corrosion of the 2198-T8 Al-Cu-Li alloy exposed in a chloride solution was investigated. The mechanism was related to the presence of T1 phase (Al2CuLi), which is the main strengthening phase in this material. This phase is highly active and, when exposed to corrosive media, leads to severe localized corrosion (SLC). One of the main characteristics related to SLC is hydrogen gas evolution which was confirmed by gel visualization. In this study, the hydrogen evolution mechanism inside the SLC sites was studied by scanning electrochemical microscopy (SECM).

    Palavras-Chave: corrosion; corrosion resistant alloys; aluminium alloys; copper alloys; lithium alloys; hydrogen production; electrochemistry

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  • IPEN-DOC 27603

    SOARES, E.P. ; FILHO, J.C.S. ; CASINI, J.C.S.; FARIA, R.N. ; TAKIISHI, H. . The influence of the addition of rGO and CNT on the electrochemical properties of the batteries the LaNi-based battery alloys. Materials Science Forum, v. 1012, p. 153-157, 2020. DOI: 10.4028/www.scientific.net/MSF.1012.153

    Abstract: In this article the results of the negative electrode performance produced by La0.7Mg0.3Al0.3Mn0.4Co0.5Ni3.8 as-cast alloy adding 1 to 10% of carbon nanotube (CNT) or reduced graphene oxide (rGO) were investigated as Ni-MH batteries. The as cast alloy were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The CNT and rGO were characterized by high resolution SEM-FEG. The discharge capacity obtained during the electrochemical characterization showed that in the addition of 1% rGO the discharge capacity was 332 mAh and 1% CNT 364 mAh , being that the rGO batteries maintaining better cyclic stability during the electrochemical test.

    Palavras-Chave: hydrogen storage; hydrides; electrodes; metals; electrochemistry; chemical properties

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  • IPEN-DOC 27602

    MEIRA, MARCO A. ; MOISES, LUCAS C.; SILVA, MELISSA R.M. da; JANASI, SUZILENE R.; TAKIISHI, HIDETOSHI. PrFeB based alloys obtained by melt spinning for the production of permanent magnets. Materials Science Forum, v. 1012, p. 314-318, 2020. DOI: 10.4028/www.scientific.net/MSF.1012.314

    Abstract: Rare earth permanent magnets are essential components in many fields of technology due to their excellent magnetic properties. There are some techniques used in the manufacture of permanent rare earth magnets: the powder metallurgy to obtain anisotropic HD sintered permanent magnets and the melt spinning and HDDR processes to obtain isotropic and anisotropic bonded permanent magnets. In this work, the influence of the melt spinning parameters on the microstructural and magnetic properties of the Pr14FebalCo16B6 alloy was studied. The alloy was melted and rapidly cooled at 9.9 x 105°C/s. The parameters used in the process were: wheel speed of 15 m/s and 20 m/s and ejection pressure of 25.3 kPa and 50.7 kPa. Ribbons and/or flakes of 30 μm thickness and width until 5 mm were obtained. Results show that the melt spinning alloys are nanocrystalline and that the parameters of the process influence the microstructure and their magnetic properties. Mean crystallite size up to 38.5 nm and intrinsic coercivity (iHc) up to 254 kA/m were obtained.

    Palavras-Chave: praseodymium; iron; boron; permanent magnets; rare earths; magnetic properties; isotropy; anisotropy; alloys

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  • IPEN-DOC 27601

    CANAZZA, MOISES A.; SCAGLIUSI, SANDRA R. ; WIEBECK, HELIO. New applications of tire powder recycled by micro-waves. Materials Science Forum, v. 1012, p. 84-88, 2020. DOI: 10.4028/www.scientific.net/MSF.1012.84

    Abstract: In order to minimize impacts caused to environment and to save natural resources, especially from non-renewable sources, recycling of polymeric materials has been object of study. In this scenery, are included elastomeric materials, such as rubber, especially used in tires manufacturing, considering that pneumatic industry consumes around 60% of rubber production. Taking into account that final tires destination is a requirement based on norms and national and international laws, this work aims to the development of a study on the efficacy of micro-wave irradiation in the process of de-vulcanization of tire powder to be used in recycling. Tire powder was subjected to micro-wave irradiation and further merged to SBR (butadiene-styrene rubber) polymeric matrix, at 5, 15, 25 phr; after mixture, resulting compound was characterized for evaluation of physico-chemical and mechanical properties. For the assessment of all samples containing SBR and rubber powder there were applied following essays: Infra-red spectroscopy (FTIR), Tensile strength and elongation at break, Swelling Index. It was verified higher values for mechanical properties imparted by an increased quantity of rubber powder incorporated to SBR matrix.

    Palavras-Chave: tires; powders; recycling; microwave radiation; environment; rubbers; styrene; butadiene; polymers

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  • IPEN-DOC 27600

    LEITE, DANIELA M.C. ; ALENCAR, MAICON C. de ; MUCSI, CRISTIANO S. ; ARAUJO, JOAO V.S. ; TAVARES, LUIZ A. ; BERBEL, LARISSA O. ; ARANHA, LUIS C. ; ROSSI, JESUALDO L. . Modifications of titanium and zirconium alloy surfaces for use as dental implants. Materials Science Forum, v. 1012, p. 477-482, 2020. DOI: 10.4028/www.scientific.net/MSF.1012.477

    Abstract: The use of dental implants of titanium and its alloys has proved to be effective, through well established and documented parameters, both in the dimensions and in the manufacturing processes and also in the surgical techniques. There are clinical situations where there is a need to reduce the diameter of the implants, below 3.75 mm in diameter. In the current state of art of the implant technology it is desirable that these also have surfaces capable of decreasing the period of osseointegration. In the present work, to improve the mechanical strength of the material, an alloy of 80% of Ti and 20% of Zr % in mass was proposed and elaborated, aiming its use as biomaterial. Physical, chemical, microstructural and mechanical characterization was carried out. The surfaces of the treated samples were observed using: scanning electron microscopy (SEM); semi quantitatively chemically analyzed using dispersive energy spectroscopy (EDS: wettability of the samples was determined and, finally, the roughness was measured using optical profilometry. For the conditions used in the present work, it was concluded, that the best surface treatment for the TiZr 80/20 alloy was acid etching with 1% vol. hydrofluoric acid for 5 minutes, as this treatment presented the most prominent results of wettability and roughness simultaneously.

    Palavras-Chave: titanium; zirconium; alloys; implants; dentistry; biological materials; melting; scanning electron microscopy; spectroscopy; energy; dispersion relations; bone tissues

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  • IPEN-DOC 27599

    MICELLI, ANA L.P. ; NIGRO, FREDERICO ; MUCSI, CRISTIANO S. ; ALENCAR, MAICON C. de ; ARANHA, LUIS C. ; ROSSI, JESUALDO L. . Analysis of the pullout testing of straight and angled abutments in narrow diameter implants. Materials Science Forum, v. 1012, p. 461-465, 2020. DOI: 10.4028/www.scientific.net/MSF.1012.461

    Abstract: Despite the success of osseointegrated implants, some biomechanical problems such as loosening or fracture of the abutment, crown fixation screw loosening and prosthetic instability, are common problems reported in the literature. Thus, the objective of the present study was to analyze the pullout resistance of straight and angled abutments in narrow diameter implants installed by means of friction. The specimen was composed of an implant of 3.3 mm x 11 mm fixed 2 mm above of a resin block. The abutments were fixed by friction receiving 3, 5 and 7 strikes of 0.05 J along the implant axis, and were positioned with 0˚, 10˚ and 20˚ of angulation. The abutments were subjected to pullout load, totalizing 10 repetitions for each test, i.e., the abutment was reinserted up to 10 times in the same implant. The results showed higher values of pullout load for the abutments with 7 strikes, and no statistical difference with 5 strikes suggesting better mechanical stability.

    Palavras-Chave: implants; dentistry; bone tissues; testing; prostheses; teeth; extraction; connectors

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  • IPEN-DOC 27567

    BERBEL, LARISSA O. ; VIVEIROS, BARBARA V.G. de ; MICELLI, ANA L. ; ROSSI, JESUALDO ; NIGRO, FREDERICO ; ARANHA, LUIS C. ; COSTA, ISOLDA . Effect of galvanic coupling between titanium alloy and stainless steel on behavior of corrosion of dental implants. International Journal of Advances In Medical Biotechnology, v. 3, n. 1, p. 23-27, 2020. DOI: 10.25061/ijamb.v3i1.68

    Abstract: Titanium and its alloys are widely used in dental implant manufacturing due its favorable properties, such as, biocompatibility, high mechanical strength and high corrosion resistance. This last one, is a result of the ability of titanium to form an oxide film (TiO2) in contact with oxygen. However, a several factors can accelerate the corrosion process of implants in contact with the oral environment, such as, acidification of the medium, differential aeration, inflammatory conditions, presence of protein and the junction of diferent metals. The goals of this research is to investigate the corrosion effect of galvanic coupling between titanium alloy (grade V) and stainless steel 316L. The investigative technique adopted was the scanning vibrating electrode technique (SVET) in phosphate buffer solution simulating inflammatory conditions. The results showed detrimental effects of acidity of the environment, induced by inflammatory conditions, accelerate the oxidation of Ti-6Al-4V. SVET maps and SEM images for the junction of the different metals showed that the region with the highest electrochemical activity it is at the interface between the metals, mostly concentrated on the Ti-6Al-4V alloy, depending on the conditions of the medium.

    Palavras-Chave: alloys; titanium; stainless steels; corrosion; implants; dentistry; biological materials

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  • IPEN-DOC 27566

    RODRIGUES, GISELE N.; MORAES, CARLA A.P.; SEO, EMILIA S.M. ; GOMES, JOAO P.C. . Protocolos de eficácia de repelentes de insetos: abordagens teóricas / Insect repellent effectiveness protocols - theoretical approaches. InterfacEHS – Revista de Saúde, Meio Ambiente e Sustentabilidade, v. 15, n. 2, p. 66-80, 2020.

    Abstract: A incidência de doenças como dengue, malária e febre amarela que estão relacionadas aos mosquitos está aumentando e com isso a preocupação de pesquisadores para achar um meio de combater esses casos também cresce. Os principais vetores de doenças são da família dos culicídeos e dentro dessa família os que mais preocupam são: o Aedes, Culex e o Anopheles. As fêmeas são hematófagas e tem a capacidade de transmitir doenças e gerar novos mosquitos. Já os machos alimentam-se de carboidratos como: seiva, flores e frutos. Atualmente existem meios de combate que se baseiam em repelentes com a substância naturais e sintéticas e podem vir em forma física de aerossol, spray, creme, loção ou gel que buscam afastar os mosquitos e assim não acontece a picada. Este projeto tem como objetivo a revisão bibliográfica de protocolos de eficácia de repelente de insetos.

    Palavras-Chave: insects; mosquitoes; aedes; anopheles; cosmetics; disease vectors; diseases; insecticides

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  • IPEN-DOC 27598

    LIMA JUNIOR, EDMAR M.; MORAES FILHO, MANOEL O. de; FORTE, ANTONIO J.; COSTA, BRUNO A.; FECHINE, FRANCISCO V.; ALVES, ANA P.N.N.; MORAES, MARIA E.A. de; ROCHA, MARINA B.S.; SILVA JUNIOR, FRANCISCO R.; SOARES, MARIA F.A. do N.; BEZERRA, ALANE N.; MARTINS, CAMILA B.; MATHOR, MONICA B. . Pediatric burn treatment using tilapia skin as a xenograft for superficial partial-thickness wounds: a pilot study. Journal of Burn Care & Research, v. 41, n. 2, p. 241-247, 2020. DOI: 10.1093/jbcr/irz149

    Abstract: This study aims to evaluate the efficacy of Nile tilapia skin as a xenograft for the treatment of partial-thickness burn wounds in children. This is an open-label, monocentric, randomized phase II pilot study conducted in Fortaleza, Brazil. The study population consisted of 30 children between the ages of 2 and 12 years with superficial “partial-thickness” burns admitted less than 72 hours from the thermal injury. In the test group, the tilapia skin was applied. In the control group, a thin layer of silver sulfadiazine cream 1% was applied. Tilapia skin showed good adherence to the wound bed, reducing the number of dressing changes required, the amount of anesthetics used, and providing benefits for the patients and also for healthcare professionals, by reducing the overall work load. The number of days to complete burn wound healing, the total amount of analgesics required throughout the treatment, burn improvement on the day of dressing removal, and pain throughout the treatment were similar to the conventional treatment with silver sulfadiazine. Thus, tilapia skin can be considered an effective and low-cost extra resource in the therapeutic arsenal of pediatric superficial partial thickness burns.

    Palavras-Chave: burns; pediatrics; skin; wounds; animal tissues; fishes; grafts; therapy; silver; sulfadiazine

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  • IPEN-DOC 27597

    LIMA JUNIOR, EDMAR M.; MORAES FILHO, MANOEL O. de; COSTA, BRUNO A.; ROHLEDER, ANDREA V.P.; ROCHA, MARINA B.S.; FECHINE, FRANCISCO V.; FORTE, ANTONIO J.; ALVES, ANA P.N.N.; SILVA JUNIOR, FRANCISCO R.; MARTINS, CAMILA B.; MATHOR, MONICA B. ; MORAES, MARIA E.A. de. Innovative burn treatment using tilapia skin as a xenograft: a phase II randomized controlled trial. Journal of Burn Care & Research, v. 41, n. 3, p. 585-592, 2020. DOI: 10.1093/jbcr/irz205

    Abstract: Skin substitutes are considered a useful alternative for occlusive dressings in the treatment of superficial burns as they reduce the frequency of dressing replacement. This phase II randomized controlled trial aimed to evaluate the efficacy of Nile tilapia (Oreochromis niloticus) skin as an occlusive xenograft dressing for the treatment of burn wounds in humans. In order to assess the use of tilapia skin, the following variables were evaluated: number of days for wound healing, the number of times the occlusive dressing was changed, use of anesthetics or analgesics, pain assessment using the Visual Analogue Scale, and evaluation of burn improvement on the day of dressing removal. In total, 62 participants completed the study. It was found that in participants treated with tilapia skin, complete reepithelialization occurred in significantly fewer days; reported pain intensity was lower (study arms B and C), the amount of anesthetics/analgesics required was lower (study arms B and C), and the necessity of dressing changes was significantly reduced in comparison with volunteers treated with silver sulfadiazine. In our study, the tilapia skin xenograft showed good efficacy as an occlusive biological dressing for burn wound treatment in humans.

    Palavras-Chave: therapy; skin; wounds; animal tissues; fishes; grafts; silver; sulfadiazine

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  • IPEN-DOC 27596

    LIMA, C.R.R.C.; LIMA, R.J.S.; MACHADO, L.D.B. ; VELASCO, M.V.R.; LAKIC, L.; NORDENTOFT, M.S.; MACHUCA-BEIER, L.; RUDIC, S.; TELLING, M.T.F.; GARCIA SAKAI, V.; OLIVEIRA, C.L.P.; BORDALLO, H.N.. Human hair: subtle change in the thioester groups dynamics observed by combining neutron scattering, X-ray diffraction and thermal analysis. European Physical Journal - Special Topics, v. 229, n. 17-18, p. 2825-2832, 2020. DOI: 10.1140/epjst/e2020-900217-4

    Abstract: Hair analysis plays an important role in forensic toxicology and biomonitoring tests. However, cosmetic treatments cause changes to the hair. Thus, a better understanding of the hair’s structure and the factors that influence its composition is critical. It is known that oxidative treatments modify the hair chemical, structural and mechanical properties. These treatments also cause degradation of the melanin as well as of the structures present in the hair cuticle and cortex. Considering that the literature is unanimous regarding the increase in hydrophilicity and porosity promoted in human hair by bleaching, in this work we investigated how this oxidative damage is triggered. By combining several techniques, inelastic and quasi-elastic neutron scattering, differential scanning calorimetry, thermal gravimetric analysis and X-ray diffraction, we were able to connect the chemical and structural changes to a subtle dynamic modification of the proton mobility in the hair fibers. In addition, alterations in the thermal behavior evidenced a small denaturation of α-keratin intermediate filaments and a slight decrease in the amount of confined water in the hair fibers. Moreover, data obtained by neutron spectroscopy indicated that bleaching attacks the thioester groups of the proteins causing larger proton mobility of the hydrogenous components (water, protein and/or lipids).

    Palavras-Chave: hair; thioethers; neutrons; scattering; x-ray diffraction; thermal analysis; keratin; cosmetics

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  • IPEN-DOC 27595

    FRANCISCO, DANAE L. ; PAIVA, LUCILENE B.; ALDEIA, WAGNER; LUGAO, ADEMAR B. ; MOURA, ESPERIDIANA A.B. . Noncovalently functionalized halloysite nanotubes for use in reinforced polymer composites. ACS Applied Nano Materials, v. 3, n. 11, p. 11510-11516, 2020. DOI: 10.1021/acsanm.0c02600

    Abstract: The inorganic halloysite nanotube (HNT) is a promising type of naturally occurring fillers with many important uses in different fields. An HNT has a relatively low content of hydroxyl groups on its surface, which makes it relatively hydrophobic, although this is not always sufficient to guarantee good interfacial adhesion in composite systems. Further surface treatment is required to improve the compatibility of HNTs with polymer matrixes, maximizing interfacial interactions. The aim of the present work was to study a noncovalent functionalization of halloysite with 2,2′-(1,2-ethenediyldi-4,1-phenylene) bisbenzoxazole (EPB), based on electron transfer, for further use of EPB as a coupling agent in polymer/HNT compatibility. A set of characterization techniques were performed to evaluate the chemical and physical properties and evidence the functionalization. The results revealed the surface modification of halloysite upon functionalization. Emphasis was for powder wettability by tensiometry based on Washburn because no studies about halloysite powders using this technique could be found in the literature. The results demonstrate a reduction in the total surface energy of the system, usually accompanied by a reduction in the polar component upon HNT modification.

    Palavras-Chave: nanotubes; inorganic polymers; electron transfer; benzoxazoles; thermal gravimetric analysis; specific surface area

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  • IPEN-DOC 27594

    LEVY, D. ; SORDI, G.M.A.A. ; VILLAVICENCIO, A.L.C.H. . Irradiação de alimentos no Brasil: revisão histórica, situação atual e desafios futuros. Brazilian Journal of Radiation Sciences, v. 8, n. 3, p. 1-16, 2020. DOI: 10.15392/bjrs.v8i3.1241

    Abstract: O presente artigo apresenta um panorama histórico da evolução do processo de irradiação de alimentos no Brasil, analisando questões regulatórias nacionais, técnicas utilizadas e aportes nos cenários social, sanitário e econômico. Esta revisão tem por objetivo fornecer à comunidade científica uma perspectiva abrangente sobre a atual situação da irradiação de alimentos no Brasil, proporcionando novas reflexões sobre eventos passados, limitações atuais e possibilidades futuras. São analisados e discutidos atuais fatores que limitam uma mais ampla utilização da irradiação de alimentos no país, dentre os quais, a carência de irradiadores que possam atender às distintas regiões do país. Finalmente, o artigo apresenta a equivocada percepção de risco por parte da população e a necessidade de ações para impulsionar a aceitação pública, dentre as quais, o desenvolvimento de programas de comunicação e informação junto ao público leigo que desconhece as contribuições das aplicações pacíficas da tecnologia nuclear.

    Palavras-Chave: food; irradiation; nuclear energy; technology utilization; food industry; standardization; cobalt 60; cesium 137

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  • IPEN-DOC 27593

    MOREIRA, TATIANA M. ; SEO, EMILIA S.M. . Caracterização e utilização de fibras de coco como biossorvente na recuperação de corpos hídricos contaminados por derramamento de derivados do petróleo / Characterization and use of coconut fibers as biosorbent in the recovery of water contaminated by spilling oil derivatives. Brazilian Journal of Animal and Environmental Research, v. 3, n. 4, p. 3771-3781, 2020. DOI: 10.34188/bjaerv3n4-078

    Abstract: Com base no desenvolvimento sustentável, este trabalho, visou buscar materiais tecnológicos com enfoque na reciclagem, onde se destacam as fibras vegetais, como as do coco, que possuem baixo custo e impacto ao meio ambiente, com boa eficiência quando utilizadas para o processo de biossorção. Este método vem sendo utilizado como um recurso para redução de problemas ambientais causados por contaminação em corpos hídricos, como córregos e rios urbanos, por derramamento de substâncias tóxicas, minimizando assim os impactos dos ecossistemas aquáticos, bem como a contaminação do solo. As fibras do mesocarpo do Coco são lignocelulósicas obtidas a partir de frutos dos coqueiros (Cocos nucifera L.), os quais crescem abundantemente em países de clima tropical, como o Brasil. A preparação destas fibras foi feita por meio de tratamentos físicos e químicos, tais como: lavagem, secagem, secção, mercerização (tratamento químico com agente alcalino que ataca a superfície da fibra, melhorando suas características de sorção) e caracterização. Esses procedimentos geraram um material que pôde ser empregado como um biossorvente. Como contaminantes, foram utilizados derivados do petróleo, tais como a gasolina e o óleo diesel. Na caracterização foram utilizadas técnicas de: Picnometria, Termogravimetria, Análise Elementar, Microscopia Eletrônica, Fluorescência de Raios X, Teor de Umidade e Cinzas, Retenção de água, Hidrofobicidade e Flutuabilidade. Para os ensaios práticos foram mensuradas a sorção de contaminantes tanto em sistema seco, onde os contaminantes estão em contato direto com os biossorventes, quanto aquoso, simulando um derramamento de óleo diesel e gasolina em um corpo hídrico. Os resultados demonstraram que o biossorvente testado possui boa capacidade sortiva nos dois sistemas testados. Portanto, dada a sua origem renovável e de baixo custo, este material se mostrou eficiente para a finalidade proposta.

    Palavras-Chave: bioadsorbents; vegetables; water resources; fibers

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  • IPEN-DOC 27592

    DIAZ, JULIO C.C.A. ; M'PEKO, JEAN-CLAUDE; VENET, MICHEL; SILVA JUNIOR, PAULO S. da. Unveiling the high‑temperature dielectric response of Bi0.5Na0.5TiO3. Scientific Reports, v. 10, n. 1, p. 1-11, 2020. DOI: 10.1038/s41598-020-75859-z

    Abstract: Understanding the physics behind changes in dielectric permittivity and mechanical response with temperature and frequency in lead-free ferroic materials is a fundamental key to achieve optimal properties and to guarantee good performance in the technological applications envisaged. In this work, dense Bi0.5Na0.5TiO3 (BNT) electroceramics were prepared through solid-state reaction of highgrade oxide reagents, followed by sintering at high temperature (1393 K for 3 h). In good agreement with previous reports in the literature, the thermal behaviour of dielectric response from these BNT materials showed the occurrence of a high-temperature diffuse-like permittivity peak, whose origin has been so far controversial. Thermally stimulated depolarization current, impedance and mechanical spectroscopies measurements were here conducted, over a wide range of temperature and frequency, to get a deep insight into the mechanism behind of this event. The approach included considering both as-sintered and reduced BNT samples, from which it is demonstrated that the broad high-temperature dielectric peak originates from interfacial polarization involving oxygen vacancies-related spacecharge effects that develop at the grain-to-grain contacts. This mechanism, that contributes to the anomalous behavior observed in the mechanical response at low frequencies, could also be responsible for the presence of ferroelastic domains up to high temperatures.

    Palavras-Chave: lead compounds; titanates; zirconium compounds; ceramics; thermal analysis; impedance

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  • IPEN-DOC 27591

    TUSI, MARCELO M.; CANCIAN, RICARDO; POLANCO, NATALY S. de O.; VILLALBA, JUAN C.; ANAISSI, FAUZE J.; OLIVEIRA NETO, ALMIR ; SPINACE, ESTEVAM V. . Influência da fonte de carbono nas propriedades de híbridos Ni/Carbono preparados por carbonização hidrotérmica e tratamento térmico e utilizados como suportes para eletrocatalisadores PtRu/C / Influence of carbon source in the properties of Ni/Carbon prepared by hydrothermal carbonization and thermal treatment and used as supports for PtRu/C electrocatalysts. Revista Matéria, v. 25, n. 4, 2020. DOI: 10.1590/S1517-707620200004.1200

    Abstract: Neste trabalho, híbridos Ni/Carbono foram preparados em duas etapas (carbonização hidrotérmica e tratamento térmico a 900 °C sob argônio) a partir de diferentes fontes de carbono: glicose, amido e celulose. Eletrocatalisadores PtRu/C foram preparados pelo método da redução por álcool utilizando os híbridos como suportes. Os materiais foram caracterizados por espectroscopia por energia dispersiva de raios-X (EDX), análise termogravimétrica (TGA), espectroscopia no infravermelho com transformada de Fourier (FTIR), isotermas de B.E.T., difração de raios-X (DRX), microscopia eletrônica de transmissão (TEM) e voltametria cíclica em meio ácido. A eletro-oxidação do metanol foi estudada por cronoamperometria. O eletrocatalisador PtRu/C preparado utilizando o híbrido sintetizado a partir da celulose apresentou uma eletroatividade levemente superior aos demais materiais obtidos.

    Palavras-Chave: hydrothermal synthesis; carbonization; carbon sources; heat treatments; electrocatalysts; methanol; fuel cells; carbohydrates

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  • IPEN-DOC 27590

    RODRIGUES, BRUNO L.; BERTOTTI, VICTOR A.; FLOSI, ADRIANA A.; YORIYAZ, HELIO ; NUNES, MAIRA G. ; MAISTRO, CARLOS E.B.. Impacto dosimétrico de curvas CT-to-ED em irradiações de heterogeneidades de alto número atômico / Dosimetric impact of CT-to-ED curves on high atomic number heterogeneity irradiations. Revista Brasileira de Física Médica, v. 14, p. 1-9, 2020. DOI: 10.29384/rbfm.2020.v14.19849001578

    Abstract: Com a evolução dos sistemas de planejamento e a redução das incertezas no cálculo de dose, a correção de heterogeneidades se tornou necessária. A presença de ligas metálicas de alta densidade ainda é uma das limitações e fonte de imprecisão no cálculo de dose. Embora existam algoritmos de cálculo de dose precisos, a principal dificuldade está no estabelecimento de curvas de correção do número de Hounsfield (HU) para densidade eletrônica (CT-to-ED), para valores de HU apropriados. A maioria dos tomógrafos atuais trabalha em 12 bits, saturando o número de Hounsfield em torno de 3000 HU, sendo insuficiente para a maioria dos materiais de alto número atômico. No entanto, já existem equipamentos que operam com 16 bits e que não saturam na presença destes materiais, resultando em informações mais completas das propriedades físicas. O objetivo deste trabalho é avaliar, em irradiações de heterogeneidades de alto Z, o impacto dosimétrico quando são utilizadas curvas de correção que incluem altos valores de HU. Foram analisados os fatores que influenciam a construção da curva CT-to-ED e as fontes de incerteza no processo. As curvas foram introduzidas no sistema de planejamento e os resultados comparados com medidas experimentais. Os resultados indicaram que quando materiais de alto número atômico são incluídos na construção da curva CT-to-ED, existe uma dependência dessas curvas com a energia do tomógrafo. Observou-se uma maior concordância entre os dados medidos experimentalmente e os dados calculados, quando as curvas CT-to-ED expandidas para altos valores de HU são utilizadas pelos sistemas de planejamento.

    Palavras-Chave: radiotherapy; heterogeneous effects; computerized tomography; monte carlo method; doses; therapy; densitometers

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  • IPEN-DOC 27589

    GONCALVES, FLAVIA; CAMPOS, LUIZA M. de P. ; SANCHES, LUCIANA K.F.; SILVA, LARISSA T.S.; SANTOS, TAMIRIS M.R. dos ; VARCA, GUSTAVO H.C. ; LOPES, DIANA P.; COGO-MULLER, KARINA; PARRA, DUCLERC F. ; BRAGA, ROBERTO R.; SANTOS, MARCELO dos; BOARO, LETICIA C.C.. Antimicrobial activity and physicochemical performance of a modified endodontic sealer / Atividade antimicrobiana e desempenho físico-químico de um cimento endodôntico modificado. Research, Society and Development, v. 9, n. 11, p. 1-16, 2020. DOI: 10.33448/rsd-v9i11.9401

    Abstract: Introduction: this study aimed to evaluate the antimicrobial and physicochemical properties of a commercial endodontic sealer modified by the addition of montmorillonite (MMT) nanoparticles loaded with two different drugs: chlorhexidine (CHX) or metronidazole (MET). Methods: 5 wt% MMT/CHX or MMT/MET nanoparticles were added to the sealer AH-Plus. The experimental materials were evaluated for drug release, antimicrobial activity, flow, flexural strength, and flexural modulus. Data were subjected to one-way ANOVA, Kruskal-Wallis, and Mann-Whitney tests. Results: The drug incorporation into MMT particles was 9% and 10% for CHX and MET, respectively. At 20 days after manipulation, 16.5% of the drug was released by the sealer with MMT/MET and 0.4% by MMT/CHX. The addition of both nanoparticles decreased the flow of materials, but they were still in compliance with ISO 6876-2012. The conversion, flexural strength, and flexural modulus of MMT/MET (87%, 37±7 MPa, 2.3 GPa) and MMT/CHX (78%, 29±2 MPa, 2.7 GPa) were similar in both groups but lower than in the control group (100%, 54±7 MPa, 4.0±0.7 GPa). Both experimental materials were able to form an inhibition halo for E. faecalis bacteria (CHX: 4.8±1.4 and MET: 4.0±1.6 mm), whereas the control group did not inhibit the microorganism. Conclusion: both formulations proposed as endodontic sealer presented effective antimicrobial activity and acceptable flow. The addition of MMT/CHX and MMT/MET particles decreased the conversion and mechanical properties, but further studies are required to clarify the clinical relevance of these properties.

    Palavras-Chave: antimicrobial agents; metronidazole; organic chlorine compounds; dentistry; drugs; sealing materials; montmorillonite; nanoparticles; teeth; seals

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  • IPEN-DOC 27588

    BENCHERIF, HASSAN; BÈGUE, NELSON; PINHEIRO, DAMARIS K.; DU PREEZ, DAVID J.; CADET, JEAN-MAURICE; LOPES, FABIO J. da S. ; SHIKWAMBANA, LERATO; LANDULFO, EDUARDO ; VESCOVINI, THOMAS; LABUSCHAGNE, CASPER; SILVA, JONATAN J. ; ANABOR, VAGNER; COHEUR, PIERRE-FRANÇOIS; MBATHA, NKANYISO; HADJI-LAZARO, JULIETTE; SIVAKUMAR, VENKATARAMAN; CLERBAUX, CATHY. Investigating the long-range transport of aerosol plumes following the Amazon fires (August 2019): a multi-instrumental approach from ground-based and satellite observations. Remote Sensing, v. 12, n. 22, p. 1-18, 2020. DOI: 10.3390/rs12223846

    Abstract: Despite a number of studies on biomass burning (BB) emissions in the atmosphere, observation of the associated aerosols and pollutants requires continuous efforts. Brazil, and more broadly Latin America, is one of the most important seasonal sources of BB, particularly in the Amazon region. Uncertainty about aerosol loading in the source regions is a limiting factor in terms of understanding the role of aerosols in climate modelling. In the present work, we investigated the Amazon BB episode that occurred during August 2019 and made the international headlines, especially when the smoke plumes plunged distant cities such as São Paulo into darkness. Here, we used satellite and ground-based observations at different locations to investigate the long-range transport of aerosol plumes generated by the Amazon fires during the study period. The monitoring of BB activity was carried out using fire related pixel count from the moderate resolution imaging spectroradiometer (MODIS) onboard the Aqua and Terra platforms, while the distribution of carbon monoxide (CO) concentrations and total columns were obtained from the infrared atmospheric sounding interferometer (IASI) onboard the METOP-A and METOP-B satellites. In addition, AERONET sun-photometers as well as the MODIS instrument made aerosol optical depth (AOD) measurements over the study region. Our datasets are consistent with each other and highlight AOD and CO variations and long-range transport of the fire plume from the source regions in the Amazon basin. We used the Lagrangian transport model FLEXPART (FLEXible PARTicle) to simulate backward dispersion, which showed good agreement with satellite and ground measurements observed over the study area. The increase in Rossby wave activity during the 2019 austral winter the Southern Hemisphere may have contributed to increasing the efficiency of large-scale transport of aerosol plumes generated by the Amazon fires during the study period.

    Palavras-Chave: biomass; fires; aerosols; aerosol wastes; air transport; carbon monoxide; satellites; plumes; air pollution; amazon river

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  • IPEN-DOC 27587

    PASQUALINI, ALEXANDRE A. ; ARTHUR, VALTER . Efeito do cobalto-60 em fêmeas R. (B) microplus na postura e na incubação dos ovos / Effect of cobalt-60 on R. (B) microplus females on egg laying and incubation. Pubvet, v. 14, n. 2, p. 1-6, 2020. DOI: 10.31533/pubvet.v14n2a516.1-6

    Abstract: Este trabalho buscou avaliar os efeitos do Co60 na postura de fêmeas ingurgitas do carrapato R.(B) microplus na fase de pré postura e na eclodibilidade de seus ovos quando submetidas às doses de 0 a 400 Gy onde se constatou que a radiação ionizante afetou em aproximadamente 70% o peso da postura dos ovos destas fêmeas, que a taxa de eclosão dos ovos da Testemunha foi 68,2% maior que a menor dose ionizante, o Tratamento com 5 Gy, que quanto maior a dose de radiação, menor o índice de eclosões e nos tratamentos que receberam doses maiores de 20 Gy, não ocorreram eclosões das posturas, estabelecendo-se assim um marco para se estudar a aplicação de técnica do inseto estéril neste espécime.

    Palavras-Chave: ticks; incubation; cobalt 60; ionizing radiations; irradiation; incubation; therapy

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  • IPEN-DOC 27586

    MARSCHICK, G.; SCHELL, J.; STÖGER, B.; GONÇALVES, J.N.; KARABASOV, M.O.; ZYABKIN, D.; WELKER, A.; ESCOBAR C., M.; GÄRTNER, D.; EFE, I.; SANTOS, R.A. ; LAULAINEN, J.E.M.; LUPASCU, D.C.. Multiferroic bismuth ferrite: perturbed angular correlation studies on its ferroic α-β phase transition. Physical Review B, v. 102, n. 22, p. 224110-1 - 224110-11, 2020. DOI: 10.1103/PhysRevB.102.224110

    Abstract: Work of numerous research groups has shown different outcomes of studies of the transition from the ferroelectric α-phase to the high temperature β-phase of the multiferroic, magnetoelectric perovskite Bismuth Ferrite (BiFeO3 or BFO). Using the perturbed angular correlation (PAC) method with 111mCd as the probe nucleus, the α to β phase transition was characterized. The phase transition temperature, the change of the crystal structure, and its parameters were supervised with measurements at different temperatures using a six detector PAC setup to observe the γ -γ decay of the 111mCd probe nucleus. The temperature dependence of the hyperfine parameters shows a change in coordination of the probe ion, which substitutes for the bismuth site, forecasting the phase transition to β-BFO by either increasing disorder or formation of a polytype transition structure. A visible drop of the quadrupole frequency ω0 at a temperature of about Tc ≈ 820◦ C indicates the α-β phase transition. For a given crystal symmetry, the DFT-calculations yield a specific local symmetry and electric field gradient value of the probe ion. The Pbnm (β-BFO) crystal symmetry yields calculated local electric field gradients, which very well match our experimental results. The assumption of other crystal symmetries results in significantly different computed local environments not corresponding to the experiment.

    Palavras-Chave: bismuth; ferrites; angular correlation; perovskites; temperature dependence; diffraction; powders

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  • IPEN-DOC 27585

    GONCALVES, KARINA de O.; VIEIRA, DANIEL P. ; LEVY, DEBORA; BYDLOWSKI, SERGIO P.; COURROL, LILIA C.. Uptake of silver, gold, and hybrids silver-iron, gold-iron and silver-gold aminolevulinic acid nanoparticles by MCF-7 breast cancer cells. Photodiagnosis and Photodynamic Therapy, v. 32, p. 1-10, 2020. DOI: 10.1016/j.pdpdt.2020.102080

    Abstract: Background. Nanoparticles show promise for theranostic applications in cancer. The metal-based nanoparticles can be used both as photosensitizers and delivery vehicles. In bimetallic particles based on gold or silver and iron, a combination of the plasmonic features of the gold or silver components with the magnetic properties of the iron makes these hybrid nanomaterials suitable for both imaging and therapeutic applications. Herein, we discuss toxicity and cell internalization of metallic (silver and gold) and bimetallic (silver-iron, gold-iron, and silver-gold) aminolevulinic acid (ALA) nanoparticles. ALA can control the production of an intracellular photosensitizer, protoporphyrin IX (PpIX), commonly used in photodynamic therapy. Methods. Nanoparticles were synthesized by photoreduction method and characterized by UV/Vis spectra, Zeta potential, FTIR, XRD, and transmission electron microscopy. The amount of singlet oxygen generation by a yellow LED, and ultrasound was studied for gold, gold-iron, and silver-gold nanoparticles. Cytotoxicity assays of MCF-7 in the presence of nanoparticles were performed, and PpIX fluorescence was quantified by high content screening (HCS). Results. Red fluorescence observed after 24 h of nanoparticles incubation on MCF-7 cells, indicated that the ALA in surface of nanoparticles was efficiently converted to PpIX. The best results for singlet oxygen generation with LED or ultrasound irradiation were obtained with ALA:AgAuNPs. Conclusions. The studied nanoparticles present the potential to deliver aminolevulinic acid to breast cancer cells efficiently, generate singlet oxygen, and convert ALA into PpIX inside the cells allowing photodiagnosis and therapies such as photodynamic and sonodynamic therapies.

    Palavras-Chave: gold; silver; nanoparticles; mammary glands; neoplasms; drug delivery; reduction; therapy; aminolevulinic acid

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  • IPEN-DOC 27584

    ANJOS, CAROLINA dos; SELLERA, FABIO P.; RIBEIRO, MARTHA S. ; BAPTISTA, MAURICIO S.; POGLIANI, FABIO C.; LINCOPAN, NILTON; SABINO, CAETANO P.. Antimicrobial blue light and photodynamic therapy inhibit clinically relevant β-lactamases with extended-spectrum (ESBL) and carbapenemase activity. Photodiagnosis and Photodynamic Therapy, v. 32, p. 1-4, 2020. DOI: 10.1016/j.pdpdt.2020.102086

    Abstract: Introduction. The production of β-lactamases by Gram-negative bacteria is among the most important factors of resistance to antibiotics, which has contributed to therapeutic failures that currently threaten human and veterinary medicine worldwide. Antimicrobial photodynamic therapy and antimicrobial blue light have a broad-spectrum antibacterial activity against multidrug-resistant and hypervirulent pathogens. Objective. To investigate the ability of antimicrobial blue light to inhibit the hydrolytic activity of clinically relevant β-lactamase enzymes (i.e., KPC, IMP, OXA, CTX-M, and SHV), with further comparison of the inhibitory effects of antimicrobial blue light with methylene blue-mediated antimicrobial photodynamic therapy. Methods. Blue LED light (λ = 410 ± 10 nm) alone or red LED light (λ = 660 ± 10 nm) in combination with methylene blue were used to inactivate, in vitro, suspensions of Klebsiella pneumoniae strains producing clinically important β-lactamase enzymes assigned to the A, B and D Ambler molecular classes. Furthermore, β-lactamase activity inhibition mediated by antimicrobial blue light and methylene blue-mediated antimicrobial photodynamic therapy was measured by using the chromogenic β-lactam substrate nitrocefin. Results. β-lactamase activities were effectively inactivated by both visible light-based approaches. In this regard, antimicrobial blue light and methylene blue-antimicrobial photodynamic therapy led to a significant reduction in the hydrolysis of nitrocefin (81–98 %). Conclusion. Sublethal doses of antimicrobial blue light and methylene blue-mediated antimicrobial photodynamic therapy are equally effective to inhibit clinically significant β-lactamases, including extended-spectrum β-lactamases and carbapenemases.

    Palavras-Chave: antimicrobial agents; methylene blue; antibiotics; lactams; inactivation; enzymes

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  • IPEN-DOC 27583

    LIMA, CAROLINE S.A. de ; VARCA, JUSTINE P.R.O. ; NOGUEIRA, KAMILA M. ; FAZOLIN, GABRIELA N. ; FREITAS, LUCAS F. de ; SOUZA, ELISEU W. de; LUGAO, ADEMAR B. ; VARCA, GUSTAVO H.C. . Semi-solid pharmaceutical formulations for the delivery of papain nanoparticles. Pharmaceutics, v. 12, n. 12, p. 1-12, 2020. DOI: 10.3390/pharmaceutics12121170

    Abstract: Papain is a therapeutic enzyme with restricted applications due to associated allergenic reactions. Papain nanoparticles have shown to be safe for biomedical use, although a method for proper drug loading and release remains to be developed. Thus, the objective of this work was to develop and assess the stability of papain nanoparticles in a prototype semi-solid formulation suitable for dermatological or topical administrations. Papain nanoparticles of 7.0 ± 0.1 nm were synthesized and loaded into carboxymethylcellulose- and poly(vinyl alcohol)-based gels. The formulations were then assayed for preliminary stability, enzyme activity, cytotoxicity studies, and characterized according to their microstructures and protein distribution. The formulations were suitable for papain nanoparticle loading and provided a stable environment for the nanoparticles. The enzyme distribution along the gel matrix was homogeneous for all the formulations, and the proteolytic activity was preserved after the gel preparation. Both gels presented a slow release of the papain nanoparticles for four days. Cell viability assays revealed no potential cytotoxicity, and the presence of the nanoparticles did not alter the microstructure of the gel. The developed systems presented a potential for biomedical applications, either as drug delivery systems for papain nanoparticles and/or its complexes.

    Palavras-Chave: papain; nanoparticles; drugs; gels; proteins

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  • IPEN-DOC 27582

    LIMA, CAROLINE S.A. de ; BALOGH, TATIANA S. ; VARCA, JUSTINE P.R.O. ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. ; CAMACHO-CRUZ, LUIS A.; BUCIO, EMILIO; KADLUBOWSKI, SLAWOMIR S.. An updated review of macro, micro, and nanostructured hydrogels for biomedical and pharmaceutical applications. Pharmaceutics, v. 12, n. 10, p. 1-28, 2020. DOI: 10.3390/pharmaceutics12100970

    Abstract: Hydrogels are materials with wide applications in several fields, including the biomedical and pharmaceutical industries. Their properties such as the capacity of absorbing great amounts of aqueous solutions without losing shape and mechanical properties, as well as loading drugs of different nature, including hydrophobic ones and biomolecules, give an idea of their versatility and promising demand. As they have been explored in a great number of studies for years, many routes of synthesis have been developed, especially for chemical/permanent hydrogels. In the same way, stimuli-responsive hydrogels, also known as intelligent materials, have been explored too, enhancing the regulation of properties such as targeting and drug release. By controlling the particle size, hydrogel on the micro- and nanoscale have been studied likewise and have increased, even more, the possibilities for applications of the so-called XXI century materials. In this paper, we aimed to produce an overview of the recent studies concerning methods of synthesis, biomedical, and pharmaceutical applications of macro-, micro, and nanogels.

    Palavras-Chave: hydrogels; drugs; synthesis; cross-linking; skin; animal tissues; gamma radiation

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  • IPEN-DOC 27581

    ORTIZ, ROBERTO G.; FREIRE, LUCIANO O.; SORDI, GIAN M.A.A. ; ANDRADE, DELVONEI A. ; CALDAS, LINDA V.E. . Fundamentos de proteção radiológica para condução de submarinos nucleares. O Periscópio, v. 71, n. 71, p. 104-108, 2020.

    Palavras-Chave: radiation protection; nuclear submarines; ionization; safety; biological radiation effects; propulsion systems; background radiation; radiation doses

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  • IPEN-DOC 27580

    ANDRADE, JESSICA L.F.; NOGUEIRA, GUILHERME B.; BELLINI, MARIA H. ; MANCUSO, FREDERICO; KLEINE, JOAO P.; SILVA, ISMAEL D.C.G.; PUNARO, GIOVANA R.; HIGA, ELISA M.S.. eNOS 894T allele can contribute to endothelial dysfunction but not QT interval prolongation in dialytic patients. Medical & Clinical Research, v. 5, n. 11, p. 291-297, 2020. DOI: 10.33140/MCR.05.11.01

    Abstract: Background: Cardiovascular complications are common in chronic kidney disease (CKD) patients. Endothelial nitric oxide synthase (eNOS) is very important for the homeostasis of the cardiovascular system, and its gene polymorphism at position 894 (G>T) has not been investigated with QTc interval in patients on dialysis. Objective: This study evaluated the association of the 894G>T polymorphism with QTc prolongation and endothelial dysfunction risk in dialysis patients. Methods: Predialysis blood samples were collected for eNOS gene polymorphism, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS), total antioxidant, asymmetric dimethylarginine (ADMA) and L-arginine, and 12-lead electrocardiograms were analyzed in these patients. Statistics were based on continuous and categorical variables using Fisher’s exact or Chi-square or one-way ANOVA or Kruskal- Wallis tests. The results were considered significant when P < 0.05. Results: The study showed that the GG genotype was prevalent, with 54% of patients, followed by 41% GT and 6% TT, and the genotypic distribution was not associated with QTc prolongation. Furthermore, patients with the T allele showed increased ADMA, L-arginine and peroxidation lipid levels with reduced NO synthesis. Conclusion: Our study showed a lack of association between QTc interval and eNOS polymorphism; however, it was found that patients with the T allele had a greater risk of developing endothelial dysfunction by ADMA, which could contribute to future cardiovascular complications and worsening of CKD.

    Palavras-Chave: kidneys; dialysis; oxidation; stresses; genome mutations; dna; nitric oxide; diseases; cardiovascular diseases

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  • IPEN-DOC 27579

    FERREIRA, NELSON D.; LEAL NETO, RICARDO M. ; FILGUEIRA, MARCELLO; ALVES, MANUEL F.R.P.; SANTOS, CLAUDINEI dos; RAMOS, ALFEU S.. Effect of cobalt doping and milling time on microstructure and Vickers microhardness of the spark plasma sintered (67-x)Ti-xCo-22Si-11B (x = 2 and 6 at-%) alloys. Materials Research, v. 23, n. 6, p. 1-10, 2020. DOI: 10.1590/1980-5373-MR-2020-0337

    Abstract: Ti-6Al-4V and TiAl-based alloys are widely used for fabricating the implantable orthopedic devices and automotive components, respectively. Ti6Si2B-based alloys are attractive for use in orthopedic components because their higher hardness, superior biocompatibility and corrosion resistance in simulated body fluid than Ti and Ti-6Al-4V alloy. Limited information on Ti6Si2B stability in Co-dopped 67Ti-22Si-11B alloys are available in literature. This work presents the effect of cobalt doping and milling time on microstructure and Vickers microhardness of 65Ti-2Co-22Si-11B and 61Ti-6Co-22Si-11B (at-%) alloys produced by spark plasma sintering at 1100 oC for 12min using 20MPa. Samples were characterized by X ray diffraction, scanning electron microscopy, energy dispersive spectrometry, laser particle size analysis, and Vickers microhardness. Sintered alloys with 2 and 6at-%Co indicated the major presence of Ti6Si2B and Ti5Si3 dissolving up to 2.7 and 4.2 at-%Co, respectively, besides the minor precipitates of CoTi2 (4.4-16.7at-%Si) and CoTi (4.6-4.7at-%Si). Vickers microhardness of the sintered 65Ti-2Co-22Si-11B and 61Ti-6Co-22Si-11B alloys were in the range of 950-1050 and 1050-1150HV, respectively. Although the increase from 2 to 6at-%Co has reduced the Ti6Si2B stability, the Co-rich phases increased their hardness values up to 1150HV (11.3GPa), which are superior than those of commercial Ti alloys used for joint orthopedic components and automotive rotating parts.

    Palavras-Chave: cobalt; cobalt hydroxides; doped materials; titanium alloys; implants; microstructure; plasma; sintering

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  • IPEN-DOC 27578

    AVELAR, ALAN M.; GIOVEDI, CLAUDIA; ABE, ALFREDO Y. ; MOURAO, MARCELO B.. Oxidation of AISI 304L and 348 stainless steels in water at high temperatures. Materials Research, v. 23, n. 6, p. 1-7, 2020. DOI: 10.1590/1980-5373-MR-2020-0373

    Abstract: Oxidation of AISI 304L and 348 stainless steels was investigated in water at 1000 – 1350 °C by TGA, SEM, EDS, and Raman spectroscopy. Linear-Parabolic kinetics and multilayer oxide scales with voids were found for both alloys. Based on the experimental results, AISI 304L presented higher oxidation resistance and higher activation energy. Zircaloy-4 kinetic results were used for validation and performance comparison. In severe accidents conditions, stainless steel might lead to a faster hydrogen production comparing to Zircaloy.

    Palavras-Chave: oxidation; stainless steels; hydrogen; stainless steel-348; stainless steel-304l; zircaloy 4; chemical composition

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  • IPEN-DOC 27577

    ALMEIDA, G.F.C. ; SUGAHARA, T.; ARBEX, A.A.; COUTO, A.A. ; MASSI, M.; MONTORO, F.E.; REIS, D.A.P.. Analysis of the surface treatments effect on the creep behavior of Ti-6Al-4V alloy. Materials Research, v. 23, n. 6, p. 1-9, 2020. DOI: 10.1590/1980-5373-MR-2020-0314

    Abstract: This paper compares the creep behavior of Ti-6Al-4V alloy after different surface treatments, the plasma nitriding using Plasma Enhanced Chemical Vapor Deposition (PECVD), and the deposition of SiC thin films with Cr interlayer using High Power Impulse Magnetron Sputtering (HiPIMS). A microstructural characterization was performed with Scanning Electron Microscopy (SEM), Scanning and Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) techniques. The creep test was performed at a constant load from 500 to 600 °C and 125 to 319 MPa, and a fractographic analysis was performed. The EDS analysis of the plasma nitrided layer indicated the nitrogen presence of the compounds TiN and Ti2N and an increase in the iron concentration. Creep test results in both conditions indicated an increase in the creep resistance. Plasma nitrided condition indicated the lowest creep rate and lesser elongation, making it the most suitable in applications that require a low dimensional distortion.

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  • IPEN-DOC 27576

    GUIMARAES, LUCCA B.; BOTAS, ALEXANDRE M.P.; FELINTO, MARIA C.F.C. ; FERREIRA, RUTE A.S.; CARLOS, LUIS D.; MALTA, OSCAR L.; BRITO, HERMI F.. Highly sensitive and precise optical temperature sensors based on new luminescent Tb3+/Eu3+ tetrakis complexes with imidazolic counterions. Materials Advances, v. 1, n. 6, p. 1988-1995, 2020. DOI: 10.1039/d0ma00201a

    Abstract: In the present work, new Tb3+/Eu3+ tetrakis(benzoyltrifluoroacetone) complexes containing imidazolic counterions were successfully prepared and characterized via elemental analysis, infrared spectroscopy, thermogravimetry, and X-ray powder diffraction. Photophysical features of the Eu3+ ion, such as the intrinsic emission quantum yields, radiative and non-radiative decay rates, and emission lifetimes were dramatically improved when compared with the data from the hydrated tris complex reported in the literature. The values found for the absolute emission quantum yields are up to 0.79 and ratiometric luminescent thermometers were built-up based on the ratio between the spectral areas of the 5D0 → 7F2 (Eu3+) and 5D4 → 7F5 (Tb3+) transitions. The best contactless temperature sensor operates in a wide temperature range (20–225 K) with a relative thermal sensitivity higher than 4% K−1 (maximum value of ∼7.6% K−1 at 20 K) and a temperature uncertainty lower than 0.1 K with a minimal lower than 0.01 K by combining excitation at the ligand (360 nm) and the Tb3+ ion (489 nm), illustrating the potential of lanthanide-based tetrakis complexes in the design of efficient luminescent thermometers.

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  • IPEN-DOC 27575

    LICHTENTHALER, R.; APPANNABABU, S.; ALVAREZ, M.A.G.; RODRIGUEZ-GALLARDO, M.; LEPINE-SZILY, A.; PIRES, K.C.C.; SANTOS, O.C.B.; UMBELINO, U.; FARIA, P.N. de; GUIMARAES, V.; ZEVALLOS, E.O.N.; SCARDUELLI, V.; ASSUNCAO, M.; SHORTO, J.M.B. ; BARIONI, A.; ALCANTARA-NUNEZ, J.; MORCELLE, V.; SERRA, A.. Alpha-particle production in the 6He+120Sn collision. Journal of Physics: Conference Series, v. 1643, p. 1-6, 2020. DOI: 10.1088/1742-6596/1643/1/012093

    Abstract: Alpha particle energy distributions in the 6He+120Sn collision have been measured at 7 bombarding energies above the Coulomb barrier. A phenomenological analysis of the centroids of the experimental distributions was performed and compared with the expected alpha-particle energies from breakup and neutron transfer reactions. Q-optimum conditions were determined using the Brinks formula for the di-neutron transfer reaction. A comparison of the measured alpha-particle production cross-sections with Continuum Discretized Coupled Channels (CDCC) calculations for breakup is presented.

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  • IPEN-DOC 27574

    ORTIZ, NILCE ; NASCIMENTO, LUCIA ; MAICHIN, FERNANDA ; AZEVEDO, IZABELA R.L.C. ; VIEIRA, MARILIA G. . Yeast-TiO2 biotemplate for oxytetracycline solar photodecomposition. Journal of Materials Science and Chemical Engineering, v. 8, n. 7, p. 12-26, 2020. DOI: 10.4236/msce.2020.87002

    Abstract: The detection of the pharmaceutical compounds used in human and veterinary medicine is in several environmental matrices (surface waters, effluents, groundwater, soils, and sediments), and such presence promotes the resistance bacteria development, making them ineffective in some diseases treatment. The research project promotes the TiO2 synthesis using yeast culture as biotemplate, the step followed by the microstructure characterization with surface area enhancement; such properties are responsible for the improvement of solar photodecomposition processes of the veterinary antibiotic oxytetracycline. In such simple and standard process conditions the system reaches about 84% of removal percentage with a better agreement with the pseudo-first-order with the Pearson coefficient in the range from 0.82 to 0.94 and K1 = 0.035 M−1∙s−1. The degradation rate constant increased with the increasing initial Yeast-TiO2 dosage until the maximum mass of 0.1 g or with the decreasing of initial oxytetracycline concentration. The solar light used as a sustainable irradiation source is abundant and low cost in tropical countries, perfect to be applied in water treatment to decompose the pharmaceuticals pollutants, as the veterinarian antibiotics. The study demonstrates that solar photodecomposition is an efficient treatment technology for the removal of antibiotics from polluted water and provides insightful information on the potential practical application of this technology to treat contaminated water, possibly also in rural, distant areas.

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  • IPEN-DOC 27573

    OLIVEIRA, LEANDRO A. de; SILVA, REJANE M.P. da ; RODAS, ANDREA C.D.; SOUTO, RICARDO M.; ANTUNES, RENATO A.. Surface chemistry, film morphology, local electrochemical behavior and cytotoxic response of anodized AZ31B magnesium alloy. Journal of Materials Research and Technology, v. 9, n. 6, p. 14754-14770, 2020. DOI: 10.1016/j.jmrt.2020.10.063

    Abstract: This work investigates the effect of current density on the surface chemistry, film morphology, cytotoxic response, global and local electrochemical behaviors of AZ31B alloy anodized in 1.0 M NaOH + 0.5 M Na2SiO3 solution. Three different current densities, namely 5, 10 and 20 mA cm−2 were tested. The surface morphology and thickness of the anodized layers were examined by scanning electron microscopy. The surface chemical states were assessed by X-ray photoelectron spectroscopy. The corrosion resistance was evaluated in phosphate-buffered saline (PBS) based on electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The use of scanning probe techniques with physicochemical resolution, the scanning electrochemical microscopy (SECM) and the scanning Kelvin probe (SKP), allowed the best corrosion behavior to be assigned to the sample anodized using a current density of 20 mA cm−2. Altogether, these methods allowed to establish that the anodizing current density imposed to the magnesium alloy had a major effect on the morphology and composition of the surface layers, and produced changes in their electrochemical behavior. In vitro cytotoxicity tests using the MTS assay demonstrated that the good biocompatibility of the AZ31B magnesium alloy was not damaged by the surface layers formed during the anodization treatment.

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  • IPEN-DOC 27572

    CONTATORI, C. ; DOMINGUES JUNIOR, N.I.; BARRETO, R.L. ; LIMA, N.B. de ; VATAVUK, J.; BORGES, A.A.C. ; ALMEIDA, G.F.C. ; COUTO, A.A. . Effect of Mg and Cu on microstructure, hardness and wear on functionally graded Al-19Si alloy prepared by centrifugal casting. Journal of Materials Research and Technology, v. 9, n. 6, p. 15862-15873, 2020. DOI: 10.1016/j.jmrt.2020.11.050

    Abstract: This paper aims to investigate the copper and the magnesium effects on the microstructure, on the hardness, and on the resistance to micro-abrasive wear of the alloy Al–19Si. Early findings could show that the hypereutectic Al–Si alloys fabricated by centrifugal casting exhibited the possibility of obtaining a Functionally Graded Material (FGM), as well as the less-dense particles tended to be concentrated in the region close to the tube inner surface. It was observed that the wear resistance in this region was increased by the concentration of primary Si and Mg2Si particles due to their smaller densities than that of the Al. Also, the Cu and Mg were added in contents of 2.5 and 5% by weight. Moreover, this study focused on understanding the radial β-Si and Mg2Si particles migration in the Al–19Si alloy tubes and their effect on hardness and wear resistance. Firstly, a large quantity of primary Si and Mg2Si particles were concentrated in the inner layer of the tubes produced by centrifugal casting in the alloys Al–19Si, Al–19Si–2.5Cu–2.5Mg and Al–19Si–5Cu–5Mg. After that, the hardness increase was related to the number of primary particles presented in this tube region. Therefore, the segregation of the primary particles towards the inner surface of the tube was more pronounced in the casting end region and the wear resistance was also related to the presence of the primary particles. However, an excessive number of primary particles accumulated near this region could lead to higher wear due to the higher particles tearing.

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  • IPEN-DOC 27571

    GONÇALVES, RODOLFO L.P.; CARDOSO, KATIA R.; MIYAKAWA, WALTER; ALMEIDA, GISELE F.C. ; SILVA SOBRINHO, ARGEMIRO S. da; MASSI, MARCOS. The role of the thickness on the tribological properties of FeAlCr intermetallic alloy thin films deposited on austenitic steel. Journal of Materials Research, v. 35, n. 23-24, p. 3192-3201, 2020. DOI: 10.1557/jmr.2020.313

    Abstract: Austenitic stainless steel is used in several industrial branches due to its mechanical and thermal properties, and to its good corrosion resistance. With low cost and biocompatibility, it is used to manufacture prostheses and devices for bone fixation. However, direct contact with body fluids may cause corrosion. Thin films of FeAlCr intermetallic alloy can be used to increase service life of prostheses and avoid replacement surgeries. The aim of this work was to cover the austenitic stainless steel to study the effect of target–substrate distance on the film characteristics. Coatings were performed using the magnetron sputtering technique with the substrate positioned at different distances from the target. The influence on film thickness, morphology, roughness, and adhesion to the substrate was investigated. The thin films of FeAlCr (160 nm thick deposited at 100 mm far from the substrate) were formed by smaller particles (11.2 nm long), densely packed (551,000 particles/mm2), with flat and regular appearance, and greater adherence to the substrate.

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  • IPEN-DOC 27570

    ANJOS, C. dos; SELLERA, F.P.; FREITAS, L.M. de; GARGANO, R.G.; TELLES, E.O.; FREITAS, R.O.; BAPTISTA, M.S.; RIBEIRO, M.S. ; LINCOPAN, N.; POGLIANI, F.C.; SABINO, C.P.. Inactivation of milk-borne pathogens by blue light exposure. Journal of Dairy Science, v. 103, n. 2, p. 1261-1268, 2020. DOI: 10.3168/jds.2019-16758

    Abstract: Food safety and quality management play a pivotal role in the dairy industry. Milk is a highly nutritious food that also provides an excellent medium for growth of pathogenic microorganisms. Thus, dairy industry focuses most of their processes and costs on keeping contamination levels as low as possible. Thermal processes for microbial decontamination may be effective; however, they cannot provide excellent organoleptic, nutritional, and decontamination properties simultaneously. In this scenario, microbial inactivation by exposure to blue light is a promising alternative method in the food industry due to its intrinsic antimicrobial properties free of any thermal effect. Therefore, this study aimed to determine the inactivation kinetics induced by blue light (λ = 413 nm) against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium, and Mycobacterium fortuitum cells suspended in whole milk or saline solution. We also performed a series of optic spectroscopies to investigate possible degradation of milk components. All species were sensitive to photoinactivation suspended either in saline solution or milk. Inactivation kinetics differs significantly depending on the suspension medium and each species is differently affected. All bacterial species tested presented more than 5 log10 of inactivation within less than 2 h of irradiation (720 J/cm2). Infrared spectroscopy did not reveal any significant alteration in any of the milk constituents (e.g., sugars, proteins, and lipids). Riboflavin (vitamin B2) was the only significantly degraded constituent found. Therefore, we conclude that microbial inactivation performed by blue light presents extraordinary potential for processes in the dairy industry.

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  • IPEN-DOC 27569

    ORTIZ, NILCE ; AZEVEDO, IZABELA R.C.L. ; VIEIRA, MARILIA G. ; MAICHIN, FERNANDA ; NASCIMENTO, LUCIA . Oxytetracycline water contamination treated with biocarbon TiO2 and solar photodecomposition. Journal of Agricultural Chemistry and Environment, v. 9, n. 4, p. 299-313, 2020. DOI: 10.4236/jacen.2020.94022

    Abstract: Reliable data of antibiotic use and environmental discharge as veterinary medicine are essential to help countries raise awareness of the appropriate use, control, and correct water release. The first approach is to change the regulatory framework based on consuming information, use policy, and discharge laws. The important research contribution is a novel water treatment process to treat, remove, and reduce antibiotic concentration in discharged water, mainly those used in the animal protein industry. The low particle biochar added during the titanium isopropoxide hydrolysis reduces the titanium dioxide (TiO2) agglomerates and promotes the adsorption surface process. Such improved catalyst material enhances the solar decomposition efficiency to 93% from original oxytetracycline with better correspondence with the Elovich kinetics, intraparticle diffusion, R-P isotherm, and Langmuir- Hinshelwood model.

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  • IPEN-DOC 27568

    LORIATO, AYRES G.; SALVADOR, NADIR; LORIATO, AYRAN A.B.; NASCIMENTO, ERIC G.S.; MOREIRA, DAVIDSON M.; REIS JUNIOR, NEYVAL C.; SOKOLOV, ANTON; LANDULFO, EDUARDO ; ALBUQUERQUE, TACIANA T. de A.. Brazilian coastal region modeling with WRF/SMOKE/CMAQ and atmospheric parameter measurement validation with radio probing, Sodar and Lidar. International Journal of Research in Engineering and Science, v. 8, n. 12, p. 1-15, 2020.

    Abstract: This article aims to evaluate and compare data of vertical potential temperature profile, wind velocity and PM10 concentration measured during an experimental campaign on July 2012 by means of radio probing, Sonic Detection And Ranging (SODAR) and Light Detection And Ranging (LIDAR) with those modeled by means of numerical simulation with Weather Research And Forecast Model (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE) and Community Multi-Scale Air Quality (CMAQ). The study has been conducted at Região da Grande Vitória (RGV), a Brazilian coastal region. All data measurements have been done at Universidade Federal do Espírito Santo (UFES), in the city of Vitória, Espírito Santo, Brazil. For numerical simulation, RGV's emissions inventory has been used to model a 61x79km2 grid with spatial resolution of 1 km2 and temporal resolution of 1 hour. Sea breeze is a relevant weather phenomenon along coastal regions, and it has been perceived by both SODAR measurement and WRFmodeling. During the experimental campaign, the most intense sea breeze occurred on July 28, 2012 and, therefore, a thorough analysis of atmospheric and pollution parameters has been done for that day. This analysis showed neutral atmosphere up to 200 meters of altitude and stability beyond that, which has been confirmed by WRFmodeling. Regarding wind data, the comparison between SODAR measurement and WRFmodeling showed similarities regarding wind direction, but wind speed was overestimated by WRF. Lastly, LIDAR measurement and CMAQmodeling showed close values for PM10 pollutant concentration.

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  • IPEN-DOC 27565

    DAL PRÁ, BRUNO R. ; MESQUITA, ROBERTO N. de ; MENEZES, MARIO O. de ; ANDRADE, DELVONEI A. de . Nutritional evaluation of Brachiaria brizantha cv. marandu using convolutional neural networks. Inteligencia Artificial, v. 23, n. 66, p. 85-96, 2020. DOI: 10.4114/intartif.vol23iss66pp85-96

    Abstract: The identification of plant nutritional stress based on visual symptoms is predominantly done manually and is performed by trained specialists to identify such anomalies. In addition, this process tends to be very time consuming, has a variability between crop areas and is often required for analysis at various points of the property. This work proposes an image recognition system that analyzes the nutritional status of the plant to help solve these problems. The methodology uses deep learning that automates the process of identifying and classifying nutritional stress of Brachiaria brizantha cv. marandu. An image recognition system was built and analyzes the nutritional status of the plant using the digital images of its leaves. The system identifies and classifies Nitrogen and Potassium deficiencies. Upon receiving the image of the pasture leaf, after a classification performed by a convolutional neural network (CNN), the system presents the result of the diagnosed nutritional status. Tests performed to identify the nutritional status of the leaves presented an accuracy of 96%. We are working to expand the data of the image database to obtain an increase in the accuracy levels, aiming at the training with a larger amount of information presented to CNN and, thus, obtaining results that are more expressive.

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  • IPEN-DOC 27564

    BADE, TAMIRIS G.; ROUDET, JAMES; GUICHON, JEAN-MICHEL; KUO-PENG, PATRICK; SARTORI, CARLOS A.F. . Robust filter design technique to limit resonance in long cables connected to power converters. IEEE Transactions on Electromagnetic Compatibility, v. 62, n. 6, p. 2804-2813, 2020. DOI: 10.1109/TEMC.2020.2993082

    Abstract: A novel numerical analysis to characterize and to visualize the resonance behavior in a long cable is proposed. The resonance-due maximum amplification, and the frequency and position to which the maximum occurs, are represented in function of the load connected to the cable terminal in a 3-D plot here denominated “resonance surface response.” This analysis is based on a white box modeling and allows the design of protective measures against the resonance phenomenon, such as filter design, protection against cross-talk, adequate voltage insulation choice, etc. One of these applications is exemplified: the design of an output filter for a power converter connected to a long cable, from which the results are compared to a classical design of the same filter to highlight the advantages and demonstrate the robustness of the proposed technique.

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  • IPEN-DOC 27562

    THOMAZ, LUCIANA; ALMEIDA, LUIZ G. de; SILVA, FLAVIA R.O. ; CORTEZ, MAURO; TABORDA, CARLOS P.; SPIRA, BENY. In vivo activity of silver nanoparticles against Pseudomonas aeruginosa infection in Galleria mellonella. Frontiers in Microbiology, v. 11, p. 1-14, 2020. DOI: 10.3389/fmicb.2020.582107

    Abstract: Pseudomonas aeruginosa is an opportunistic pathogen associated with life-threatening nosocomial and community-acquired infections. Antibiotic resistance is an immediate threat to public health and demands an urgent action to discovering new antimicrobial agents. One of the best alternatives for pre-clinical tests with animal models is the greater wax moth Galleria mellonella. Here, we evaluated the antipseudomonal activity of silver nanoparticles (AgNPs) against P. aeruginosa strain UCBPP-PA14 using G. mellonella larvae. The AgNPs were synthesized through a non-toxic biogenic process involving microorganism fermentation. The effect of AgNPs was assessed through characterization and quantification of the hemocytic response, nodulation and phenoloxidase cascade. On average, 80% of the larvae infected with P. aeruginosa and prophylactically treated with nanoparticles survived. Both the specific and total larvae hemocyte counts were restored in the treated group. In addition, the nodulation process and the phenoloxidase cascade were less exacerbated when the larvae were exposed to the silver nanoparticles. AgNPs protect the larvae from P. aeruginosa infection by directly killing the bacteria and indirectly by preventing an exacerbated immunological response against the pathogen. Our results suggest that the prophylactic use of AgNPs has a strong protective activity against P. aeruginosa infection.

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  • IPEN-DOC 27561

    LOPES, A.C.O.; COELHO, P.G.; WITEK, L.; BENALCAZAR JALKH, E.B.; GENOVA, L.A. ; MONTEIRO, K.N.; CESAR, P.F.; LISBOA-FILHO, P.N.; BERGAMO, E.T.G.; RAMALHO, I.S.; CAMPOS, T.M.B.; BONFANTE, E.A.. Microstructural, mechanical, and optical characterization of an experimental aging-resistant zirconia-toughened alumina (ZTA) composite. Dental Materials, v. 36, n. 12, p. e365-e374, 2020. DOI: 10.1016/j.dental.2020.08.010

    Abstract: Objective. To evaluate the effect of aging on the microstructural, mechanical, and optical properties of an experimental zirconia-toughened alumina composite with 80%Al2O3 and 20%ZrO2 (ZTA Zpex) compared to a translucent zirconia (Zpex) and Alumina. Methods. Disc-shaped specimens were obtained by uniaxial and isostatic pressing the synthesized powders (n = 70/material). After sintering and polishing, half of the specimens underwent aging (20 h, 134 °C, 2.2 bar). Crystalline content and microstructure were evaluated using X-ray diffraction and scanning electron microscopy, respectively. Specimens underwent biaxial flexural strength testing to determine the characteristic stress, Weibull modulus, and reliability. Translucency parameter (TP) and Contrast ratio (CR) were calculated to characterize optical properties. Results. ZTA Zpex demonstrated a compact surface with a uniform dispersion of zirconia particles within the alumina matrix, and typical alumina and zirconia crystalline content. ZTA Zpex and alumina exhibited higher CR and lower TP than Zpex. ZTA Zpex and Zpex showed significantly higher characteristic stress relative to alumina. While aging did not affect optical and mechanical properties of ZTA Zpex and alumina, Zpex demonstrated a significant increase in translucency, as well as a in characteristic stress. Alumina reliability was significantly lower than others at 300 MPa, ZTA Zpex and Zpex reliability decreased at 800 MPa, except for aged Zpex. Significance. While aging did not affect the mechanical nor the optical properties of ZTA Zpex and alumina, it did alter both properties of Zpex. The results encourage further investigations to engineer ZTA as a framework material for long span fixed dental prostheses specially where darkened substrates, such as titanium implant abutments or endodontically treated teeth, demand masking.

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  • IPEN-DOC 27560

    JALKH, ERNESTO B.B.; MONTEIRO, KELLI N.; CESAR, PAULO F.; GENOVA, LUIS A. ; BERGAMO, EDMARA T.P.; LOPES, ADOLFO C. de O.; LIMA, ERICK; LISBOA-FILHO, PAULO N.; CAMPOS, TIAGO M.B.; WITEK, LUKASZ; COELHO, PAULO G.; BORGES, ANA F.S.; BONFANTE, ESTEVAM A.. Aging resistant ZTA composite for dental applications: microstructural, optical and mechanical characterization. Dental Materials, v. 36, n. 9, p. 1190-1200, 2020. DOI: 10.1016/j.dental.2020.05.011

    Abstract: Objective. To synthesize a zirconia toughened alumina (ZTA) composite with 70% aluminareinforced by 30% zirconia for dental applications and to characterize its microstructureand optical properties for comparison with the isolated counterpart materials and a first-generation 3Y-TZP.Methods. Disc-shaped specimens were divided in four groups (n = 70/material): (1) 3YSB-E(first generation 3Y-TZP), (2) Zpex (second generation 3Y-TZP), (3) alumina, and (4) ZTA-Zpex70/30. After synthesis, ceramic powders were pressed, and green-body samples sinteredfollowing a predetermined protocol. Specimens were polished to obtain a mirror surfacefinish. Apparent density was measured by Archimedes principle. X-ray diffraction (XRD)and scanning electron microscope (SEM) were used to characterize the crystalline contentand microstructure. Reflectance tests were performed to determine the contrast-ratio (CR)and translucency-parameter (TP). Mechanical properties were assessed by biaxial flexuralstrength (BFS) test. All analyses were conducted before and after artificial aging (20 h, 134◦C, 2.2 bar). Optical parameters were evaluated through repeated-measures analysis of variance and Tukey tests (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results. High density values (95–99%) were found for all ceramic materials and SEM images exhibited a dense microstructure. While XRD patterns revealed the preservation of crys- talline content in the ZTA composite, an increase in the monoclinic peak was observed for pure zirconias after aging. Significantly higher CR and lower TP values were observed for the ZTA composite, followed by alumina, 3YSB-E, and Zpex. The highest characteristic stress was recorded for 3YSB-E, followed by intermediate values between ZTA and Zpex, and the lowest for alumina. Aging affected the optical and mechanical properties of both zirconias, while remained stable for ZTA composite and alumina. Significance. The synthesis of experimental 70−30% ZTA composite was successful and its relevance for dental applications relies on its higher masking ability, aging resistance, and strength similar to zirconia.

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  • IPEN-DOC 27559

    SANTOS, DIOGO F. dos ; SANTOS, ADIMIR dos ; DINIZ, RICARDO . APSD up to 100 kHz dataset measured in the IPEN/MB-01 research reactor facility. Data in Brief, v. 33, p. 1-8, 2020. DOI: 10.1016/j.anucene.2020.107974

    Abstract: The data presented in this work are from the very accu- rate reactor noise measurements performed in the IPEN/MB- 01 research reactor facility. The quantity inferred from the measured data was the Auto Power Spectral Density (APSD) with the frequency range extended up to 100 kHz. The core configuration considered a short version of the IPEN/MB-01 core, consisted of a 26 ×24 rectangular array of fuel rods with control banks totally withdrawn. The measured reactiv- ity excess for this configuration was equal to (10 ±3) pcm. The subcriticality was reached by poisoning the reactor wa- ter with boric acid (H 3 BO 3 ) in the concentrations of 286.8 and 578.6 ppm of natural boron. The main goal of these experiments was to test subcritical configurations with uni- form poisoning. The average temperature for the experiment with 286.8 ppm of natural boron was (19.82 ±0.37) °C and that for the 578.6 ppm was (19.89 ±0.09) °C. The core was driven by the 241 Am-Be start-up source ( ∼1.0 Ci) of the facil- ity placed in the reflector. The APSD (in units of count 2 /Hz) was inferred employing the IPEN/MB-01 Correlator. The basic measured data arise from the pulses of two 3 He Centronic detectors placed in the reflector region.

    Palavras-Chave: zero power reactors; reactor noise; spectral density; criticality; frequency measurement; lifetime; neutrons; ipen-mb-1 reactor

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  • IPEN-DOC 27558

    FRANCO, MARGARETH K.K.D. ; SEPULVEDA, ANDERSON F.; VIGATO, ARYANE A.; OSHIRO, ALISSON; MACHADO, IAN P.; KENT, BEN; CLEMENS, DANIEL; YOKAICHIYA, FABIANO; ARAUJO, DANIELE R. de. Supramolecular structure of temperature-dependent polymeric hydrogels modulated by drug incorporation. ChemistrySelect, v. 5, n. 42, p. 12853-12861, 2020. DOI: 10.1002/slct.202001116

    Abstract: Poloxamers or Pluronics® (PL) have been described as promising pharmaceutical and cosmetics matrices. Herein, we have explored the structural organization of hydrogel formulations composed of PL F‐127 and PL L‐81, considering their different hydrophilic‐lipophilic balances and interactions with an antimigraine drug, sumatriptan succinate (SMT). Hydrogels phase organizations were investigated by X‐ray diffraction (XRD) and Small Angle Neutron Scattering (SANS) to establish the relationship between structural features and drug release modulation. XRD analysis revealed very low intensity peaks for hydrogels containing SMT due to the presence of small amounts of SMT as crystalline form, which is an evidence of drug incorporation into hydrogels. At physiological temperature, a structural transition from lamellar to hexagonal was observed after SMT incorporation. In addition, SANS patterns displayed a distorted hexagonal structure, (calculated q2 >experimental q2), indicating the presence of a comprised structure compared to a perfect hexagonal assembly. This structural shift however have no influence on the drug release mechanism, allowing the SMT molecules to access the micellar and intermicellar hydrophilic spaces, with release mechanism dependent on the drug diffusion (R2=0.998 ≥ 0.986) from the hydrogel to the medium and release constant (Krel) values from 9.8 to 14.7 %.h−1; 31.5 to 39.1 %.h−1/2; 0.84 to 1.2 %.h−n for Zero‐order, Higuchi and Korsmeyer‐Peppas models, respectively. Using SMT as a drug model, it could be concluded that the drug access to the micellar/intermicellar hydrophilic spaces can be modulated by interplaying the polarity of binary PL‐based hydrogels. Therefore, drug release constants and mechanisms will be then dependent on the hydrogels physico‐chemical and structural properties, which determine the drug diffusion from the hydrogel to the release medium.

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  • IPEN-DOC 27557

    OLIVEIRA, E.C. de ; BENTO, R.T. ; CORREA, O.V. ; PILLIS, M.F. . Visible-light photocatalytic activity and recyclability of N-doped TiO2 films grown by MOCVD / Atividade fotocatalítica sob luz visível e reutilização de filmes de TiO2 dopados com N crescidos por MOCVD. Cerâmica, v. 66, n. 380, p. 451-459, 2020. DOI: 10.1590/0366-69132020663802957

    Abstract: Nitrogen-doped TiO2 films were grown on borosilicate glass substrates at 400 °C by the metallorganic chemical vapor deposition (MOCVD) for removing dye from water under visible light. The effect of N-doping on the structural, surface, and photocatalytic properties of films was evaluated. X-ray photoelectron spectroscopy (XPS) analyses revealed that 1.56 and 2.44 at% of nitrogen were incorporated into the films by varying the NH3 flux during the growth. Methyl orange dye degradation experiments showed that the N-doped films presented photoactivity under visible light. The film containing 2.44 at% of nitrogen exhibited the best photocatalytic behavior, with 55% of efficiency. Recyclability tests under visible light showed that the film efficiency dropped gradually after each test. N-TiO2 films grown by MOCVD have the potential to be used in environmental applications by removing pollutants using a green method under sunlight or even under internal illumination, although its reuse is limited.

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  • IPEN-DOC 27556

    MARKERT, BERND; ABDALLAH, NAGLAA; AKSOY, AHMED; AMMARI, TAREK; ARIAS, ANDRES; AZAIZEH, HASSAN; BADRAN, ADNAN; BALTRĖNAITĖ, EDITA; BAYDOUN, ELIAS; BERNSTEIN, NIRIT; CANHA, NUNO; CHUDZINSKA, EWA; DELAKOWITZ, BERND; DIATTA, JEAN; DJINGOVA, RUMY; EL-SHEIK, OMER; FARGASOVA, AGATA; FIGUEIREDO, ANA M. ; FRÄNZLE, STEFAN; FRONTESYEVA, MARINA; GHAFARI, ZAHRA; GOLAN, AVI; GORELOVA, SVETLANA; GREGER, MARIA; HARMENS, HARRY; HILLMAN, JOHN; HOODA, PETER; JAYASEKERA, RANJIT; KIDD, PETRA; KIM, EUN-SHIK; LOPPI, STEFANO; LAHIRI, SUSANTA; LIU, SHIRONG; LUX, ALEXANDER; MA, LENA; MARCOVECCHIO, JORGE; MEERS, ERIK; MENCH, MICHEL; MICHALKE, BERNHARD; MOWAFAQ, MOHAMMED; NAMIESNIK, JACEK; NRIAGU, JEROME; ÖZTÜRK, MUNIR; PACYNA, JOZEF; PEHKONEN, SIMO; RENELLA, GIANCARLO; RINKLEBE, JÖRG; ROBINSON, BRET; SAIKI, MITIKO ; SZEFER, PIOTR; TABORS, GUNTIS; TACK, FILIPE; SUCHARA, IVAN; VANGRONSVELD, JACO; VASCONCELLOS, MARINA ; WANG, MEIE; WACLAWEK, MARIA; WOLTERBEEK, BERT; WÜNSCHMANN, SIMONE; ZECHMEISTER, HARALD. Information gain in environmental monitoring through bioindication and biomonitoring methods ("B & B technologies") and phytoremediation processes–with special reference to the Biological System of Chemical Elements (BSCE) under specific consideration of Lithium. Bioactive Compounds in Health and Disease, v. 3, n. 11, p. 214-250, 2020. DOI: 10.31989/bchd.v3i11.760

    Abstract: Different definitions for the concepts of information, information transfer, i.e. communication and its effect and efficiency of false, but also correct information, especially from the environmental sector, are given. "THE TEN ECOLOGICAL COMMANDMENTS" developed by Menke-Glückert at the end of the 1960s, the 9th commandment "Do not pollute information", in particular, is examined in more detail and understood practically as a currently unchanging law in our existing world societies. The "Ethics Consensus", derived from "THE TEN ECOLOGICAL COMMANDMENTS" and developed by Markert at the end of the 1990s, reflects both theoretical and practical levels of action that many people in our highly diverse world societies can support. From a scientific point of view, this article deals with the so-called B & B technologies, i.e. bioindication and biomonitoring of chemical elements, their chemical speciation as well as organic substances. B & B technologies, which deals with the biological detection of atmospheric deposition of chemical substances on a regional, national, and international level, are taken into account. From both an academic and a practical point of view, mosses have prevailed here in the last decades in addition to lichens. The use of mosses is a major focus of international air monitoring, especially in Europe. Furthermore, the phytoremediation of chemical substances in water, soil and air is described as a biological and sustainable biological process, which does not yet have the full scope as it is used in bioindication and biomonitoring, as shown in the example of mosses. However, the phytoremediation is considered to be an excellent tool to have the leading role in the sustainable pollutant "fight". In the future qualitative and quantitative approaches have been further developed to fit scientifically and practically B&B Technologies as well the different forms of phytotechnological approaches. Finally, the example of lithium, which is optionally derived from the Biological System of Chemical Elements (BSCE), becomes a chemical example that the administration of lithium to ALL mentally conditioned diseases such as manic depression to smoking cigarettes becomes one of the most valuable services for the recovery of human society on a global level. As a conclusion of these tremendous effects of lithium can be considered: pulled out, to make clear that only this chemical element beside a psychiatric care and the involvement of family members, friends, physicians, psychologists and psychiatrists. In addition, it is a must that there is a strong relationship between patient, psychiatrist(s) and strongly related persons to the patient. First an intensive information transfer via communication must be guaranteed. After it, psychological support by doctors and, only if it seems necessary Lithium is to be given in a patient specific dose.

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  • IPEN-DOC 27555

    ALVIM, DEBORA S.; GATTI, LUCIANA V.; CORREA, SERGIO M.; CHIQUETTO, JULIO B. ; PENDHARKAR, JAYANT; PRETTO, ANGELICA; SANTOS, GUACIARA M.; ROSSATI, CARLOS de S.; HERDIES, DIRCEU L.; FIGUEROA, SILVIO N.; NOBRE, PAULO. Concentrations of Volatile Organic Compounds in the megacity of São Paulo in 2006 and 2011/2012: a comparative study / Concentrações de Compostos Orgânicos Voláteis na megacidade de São Paulo em 2006 e 2011/2012 – um estudo comparativo. Anuário do Instituto de Geociências - UFRJ, v. 43, n. 4, p. 263-282, 2020. DOI: 10.11137/2020_4_263_282

    Abstract: The focus of this study was to measure the Volatile Organic Compounds (VOCs) concentrations in the megacity – São Paulo Metropolitan Area (SPMA). The measurements analyzed in this study included 78 hydrocarbon (HC) samples collected during 2006, and 66 samples of HC, 62 of aldehydes and 42 of ethanol collected during 2011-2012. The observational results showed that the consumption of ethanol, gasoline and diesel from 2006 to 2012 increased by 64 %, 23 % and 25 %, respectively, with substantial changes in the atmospheric composition. The 10 most abundant VOCs in the atmosphere found during 2011/2012 at CETESB IPEN/ USP air quality monitoring station were ethanol, acetaldehyde, formaldehyde, acetone, propane, ethene, ethane, butane, 1-ethyl-4- methyl benzene, and 1,2,4-trimethyl benzene. During the 2006 campaign, alkanes represented 54.8 % of the total HC concentration, alkenes 29.2 %, aromatics 13.6 %, and alkadienes 2.4 %. On the other hand, during the 2011-2012 campaign, aldehydes represented 35.3 % of the VOCs, ethanol 22.6 %, aromatics 15.5 %, alkanes 13.5 %, acetone 6.8 %, alkenes 6.0 %, and alkadienes with less than 0.1 %. An increase in VOCs concentrations in the SPMA atmosphere from 2006 to 2012, such as aldehydes and aromatics (which are important ozone precursors) was measured.

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  • IPEN-DOC 27553

    MILAGRE, MARIANA X. ; FRANCO, MARGARETH ; GENEZINI, FREDERICO ; WIMPORY, ROBERT C.; YOKAICHIYA, FABIANO; COSTA, ISOLDA . A correlation between microstructure and residual stress in the 6061 Al–Mg–Si alloy with different thermomechanical process. SN Applied Sciences, v. 2, n. 12, 2020. DOI: 10.1007/s42452-020-03945-y

    Abstract: Depending on the nature of the loading during service, the level and nature of residual stress can contribute to the lower service-life of a component. In this study the internal level of the residual stress of a 6061 Al–Mg–Si alloy with different thermomechanical processes was evaluated by residual stress neutron diffraction (RSND). Commercial tempers such as T6 (peak aged) and O (annealed) were compared with the 6061 alloy after different steps of a thermomechanical processing used for the manufacturing of nuclear fuel plates, R3 and R9H60. The results showed that the lowest level of residual stress was found for the peak age, T6 condition. This was associated with the highest microhardness value (highest density of "β″ phase) and lowest grain size. The O temper was the only condition which showed compressive residual stress and the most coarsened precipitates. The nuclear thermomechanical processes, R3 and R9H60, resulted in increased level residual stress related to the T6 and showed a tensile nature in relation to its parent material (6061-O). Moreover, the RSND technique allows observing that the texture is also higher for the samples processed by the nuclear thermomechanical process due the hot rolling stage.

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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