Periódicos - Artigos

 

Submissões recentes

  • IPEN-DOC 28437

    SONA FILHO, CELSO R. ; CARVALHO, FLAVIO M. de S.; GUEDES-SILVA, CECILIA C. . Mechanical properties and in vitro bioactivity of silicon nitride ceramics with SiO2, CaO, and MgO additions. Journal of Biomedical Materials Research Part B: Applied Biomaterials, v. 110, n. 3, p. 507-516, 2022. DOI: 10.1002/jbm.b.34930

    Abstract: Silicon nitride ceramics with SiO2, CaO, and MgO as sintering aids were investigated in view of biomedical applications. In the current study, samples with four different compositions were pressureless sintered at 1750°C for 1 h under a nitrogen atmosphere. The samples were evaluated concerning densification, microstructure, mechanical properties, and in vitro bioactivity. Microstructures with elongated β-Si3N4 grains dispersed in an intergranular phase and with densities from 78.77 to 97.14% of the theoretical density were obtained. Higher contents of SiO2 resulted in the best densification and mechanical properties. Besides, replacements of CaO by MgO in the initial compositions affected Young's modulus and in vitro bioactivity. Considering the samples with relative density higher than 94.14%, those with lower values of Young's modulus had lower SiO2/MgO ratios. After immersion in SBF (Simulated Body Fluid), the samples with high porosity and/or partial replacements of CaO by MgO had their surfaces coated with a layer rich in calcium and phosphorus, morphologically similar to hydroxyapatite. Hence, producing silicon nitride ceramics with the potential to be used as orthopedic implants must consider ideal amounts of additives. In this article, the best combination of mechanical properties and mineralization capability was reached by the composition with low content of MgO, and high content of SiO2 and CaO.

  • IPEN-DOC 28436

    CAETANO, GABRIELA A.; GONORING, TIAGO B.; COELHO, LUCAS M.; LUZ, TEMISTOCLES de S.; ROSSI, JESUALDO L. ; ORLANDO, MARCOS T.D.A.. Mechanical properties study of a duplex stainless steel weld using physical simulation and work hardening models. Journal of Materials Engineering and Performance, v. 31, n. 1, p. 113-127, 2022. DOI: 10.1007/s11665-021-06155-8

    Abstract: Transporting substances with high radioactivity used in nuclear medicine is strategic. Lean duplex stainless steel UNS S32304 is a candidate for external construction of a cask for transporting radioactive material. Thin sheet lean duplex stainless steel specimens were welded by autogenous TIG processing (tungsten inert gas) in order to avoid neutron activation of the filler metal. Post-welding heat treatments were studied considering a possible scenario of fire or crash during transportation. The metallographic analysis indicated that post-welding heat treatments promoted a change in austenitic phase content in the fusion zone. An analysis of the stress-strain curves using work hardening models revealed that only the Voce and Hockett–Sherby models presented goodness-of-fit to the experimental data. It was demonstrated that the parameters of both models are correlated to the volumetric austenitic phase content present in the fusion zone, being equivalent to the quantification of the bulk phase. This work proposes a new direct evaluation methodology for volumetrically quantifying phases using both mathematical work hardening models fitted to the experimental data from stress-strain curves.

  • IPEN-DOC 28435

    JUNIOR, ALEXANDRE F.; RIBEIRO, CHARLENE A.; LEYVA, MARIA E.; MARQUES, PAULO S.; SOARES, CARLOS R.J. ; QUEIROZ, ALVARO A.A. de . Biophysical properties of electrospun chitosan-grafted poly(lactic acid) nanofibrous scaffolds loaded with chondroitin sulfate and silver nanoparticles. Journal of Biomaterials Applications, v. 36, n. 6, p. 1098-1110, 2022. DOI: 10.1177/08853282211046418

    Abstract: The aim of this work was to study the biophysical properties of the chitosan-grafted poly(lactic acid) (CH-g-PLA) nanofibers loaded with silver nanoparticles (AgNPs) and chondroitin-4-sulfate (C4S). The electrospun CH-g-PLA:AgNP:C4S nanofibers were manufactured using the electrospinning technique. The microstructure of the CH-g-PLA:AgNP:C4S nanofibers was investigated by proton nuclear magnetic resonance (1H-NMR), scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), and Fourier transform infrared (ATR-FTIR) spectroscopy. ATR-FTIR and 1H-NMR confirm the CH grafting successfully by PLA with a substitution degree of 33.4%. The SEM measurement results indicated apparently smooth nanofibers having a diameter range of 340 ± 18 nm with porosity of 89 ± 3.08% and an average pore area of 0.27 μm2. UV-Vis and XRD suggest that silver nanoparticles with the size distribution of 30 nm were successfully incorporated into the electrospun nanofibers. The water contact angle of 12.8 ± 2.7° reveals the hydrophilic nature of the CH-g-PLA:AgNP:C4S nanofibers has been improved by C4S. The electrospun CH-g-PLA:AgNP:C4S nanofibers are found to release ions Ag+ at a concentration level capable of rendering an antimicrobial efficacy. Gram-positive bacteria (S.aureus) were more sensitive to CH-g-PLA:AgNP:C4S than Gram-negative bacteria (E. coli). The electrospun CH-g-PLA:AgNP:C4S nanofibers exhibited no cytotoxicity to the L-929 fibroblast cells, suggesting cytocompatibility. Fluorescence microscopy demonstrated that C4S promotes the adhesion and proliferation of fibroblast cells onto electrospun CH-g-PLA:AgNP:C4S nanofibers.

  • IPEN-DOC 28434

    ZAHARESCU, TRAIAN; MATEESCU, CARMEN; DIMA, ANDREEA; VARCA, GUSTAVO H.C. . Evaluation of thermal and radiation stability of EPDM in the presence of some algal powders. Journal of Thermal Analysis and Calorimetry, v. 147, n. 1, p. 327-336, 2022. DOI: 10.1007/s10973-020-10319-4

    Abstract: In this paper, ecological-friendly materials based on ethylene–propylene–diene terpolymer (EPDM) with improved thermal and radiation stabilities by Chlorella vulgaris (CV) and Spirulina platensis (SP) powders were investigated by complementary procedures: FTIR spectroscopy and isothermal and nonisothermal chemiluminescence (CL). The stabilization potential of microalgae was evaluated at several degrees of γ-radiolysis by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, while the polymer resistances were studied on a large range of algal concentrations (1, 3, 5 and 10 mass%). The carbonyl and hydroxyl indices of all degraded EPDM formulations were found to be two times smaller in the presence of algal powders, if compared to the pristine material. Some dissimilarities between the oxidation development in pristine and modified EPDM appeared, especially in unirradiated samples. The activation energies required for the oxidation of EPDM and the lifetime of these samples at various temperatures between room temperature and 100 °C were calculated. The antioxidant compounds existing in the studied microalgae proved a significant influence on the stability of EPDM, mainly in the presence of SP, which was confirmed by the activation energies calculated from our CL results. The investigation of cycling thermal degradation revealed the obvious contribution of additives towards delaying EPDM ageing.

  • IPEN-DOC 28433

    NUNES, R.F.; TOMINAGA, F.K. ; BORRELY, S.I. ; TEIXEIRA, A.C.S.C.. UVA/persulfate-driven nonylphenol polyethoxylate degradation: effect of process conditions. Environmental Technology, v. 43, n. 2, p. 286-300, 2022. DOI: 10.1080/09593330.2020.1786166

    Abstract: UV/persulfate (UV/PS) technologies have gained increased attention as efficient alternatives for removing pollutants from different classes, although processes based on the UVA-driven S2O2−8 (PS) activation have not yet been discussed in the literature for the removal of the nonionic surfactant nonylphenol polyethoxylate (NPEO). The present study investigated the simultaneous effect of the initial persulfate concentration ([PS]0) and specific photon emission rate (EP,0) on NPEO degradation by UVA/PS following a Doehlert experimental design. The results for [NPEO]0 = (4.65 ± 0.15) mg L−1 indicated more than 97.8% NPEO removal after 2 h, with pseudo first-order specific degradation rate (kobs) of 0.0320 min−1, for [PS]0 = 7.75 mmol L−1 and EP,0 = 0.437 μmol photons L−1 s−1. Under these conditions, NPEO half-life time was about 22 min, and the EC50-48 h (% v/v) values for Daphnia similis before and after treatment did not differ significantly. Higher values of EP,0 would influence NPEO removal for [PS]0 not higher than 8–10 mmol L−1, although lower degradation efficiencies were obtained with higher [NPEO]0 or real wastewater, except for longer reaction times. Additionally, UVA/PS showed to be efficient for tensoactivity removal, despite the negligible total organic carbon (TOC) removal achieved. Finally, UVC and UVA resulted in NPEO degradation higher than 96% and similar tensoactivity removals when UVA/PS was conducted under optimal conditions ([PS]0 = 10 mmol L−1; EP,0 = 0.324 μmol photons L−1 s−1), suggesting that UVA radiation available in solar light could be advantageously employed for NPEO removal at concentrations usually found in wastewater.

  • IPEN-DOC 28432

    ALVES, ALINE V.; FERRAZ, MARIANA A.; MORENO, BEATRIZ B.; NOBRE, CAIO R.; ANTUNES, RENATA M.; PUSCEDDU, FABIO H.; BORDON, ISABELLA C. da C.L.; FAVARO, DEBORAH I.T. ; COTRIM, MARYCEL E.B. ; CHOUERI, RODRIGO B.. Microscale Toxicity Identification Evaluation (TIE) for interstitial water of estuarine sediments affected by multiple sources of pollution. Environmental Science and Pollution Research, v. 29, p. 10122-10137, 2022. DOI: 10.1007/s11356-021-15389-x

    Abstract: Estuaries in the world are affected by different contamination sources related to urbanisation and port/industrial activities. Identifying the substances responsible for the environmental toxicity in estuaries is challenging due to the multitude of stressors, both natural and anthropogenic. The Toxicity Identification and Evaluation (TIE) is a suitable way of determining causes of toxicity of sediments, but it poses difficulties since its application is labour intensive and time consuming. The aimof this study is to evaluate the diagnosis provided by a TIE based on microscale embryotoxicity tests with interstitial water (IW) to identify toxicants in estuarine sediments affected by multiple stressors. TIE showed toxicity due to different combinations of metals, apolar organic compounds, ammonia and sulphides, depending on the contamination source closest to the sampling station. The microscale TIE was able to discern different toxicants on sites subject to different contamination sources. There is good agreement between the results indicated in the TIE and the chemical analyses in whole sediment, although there are some disagreements, either due to the sensitivity of the test used, or due to the particularities of the use of interstitial water to assess the sediment toxicity. The improvement of TIE methods focused on identifying toxicants in multiple-stressed estuarine areas are crucial to discern contamination sources and subsidise management strategies.

  • IPEN-DOC 28431

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Colloidal processing of thulium-yttria microceramics. Journal of Physics and Chemistry of Solids, v. 161, p. 1-10, 2022. DOI: 10.1016/j.jpcs.2021.110420

    Abstract: The development of new dosimetric materials is essential for the safe and effective use of nuclear technology. In the present study, an eco-friendly bio-prototyping approach was developed for preparing thulium-yttria microceramics with potential applications in radiation dosimetry. Micro-powder compacts were obtained by casting colloidal thulium-yttria suspensions prepared with 20 vol% particles in thin-walled tube templates. Samples were sintered at 1600 °C for 2 h under the environmental pressure and atmosphere to obtain thulium-yttria microceramics with dimensions of 3.33 ± 0.01 mm × 2.27 ± 0.01 mm (height × diameter), as well as a cubic C-type structure, pycnometric density of 4.79 g cm−3 (95.61% theoretical density), and surface microstructure comprising hexagon-like grains bonded at the boundaries. The use of thulium as an activator of yttria greatly improved the electron paramagnetic resonance (EPR) response of the microceramics, where the main EPR peak (p1) was recorded at 351.24 mT and the g factor was 2.0046. The innovative findings obtained in this study may facilitate the production of new solid state dosimeters.

  • IPEN-DOC 28430

    PALHARIM, PRISCILA H.; FUSARI, BEATRIZ L.D. dos R.; RAMOS, BRUNO; OTUBO, LARISSA ; TEIXEIRA, ANTONIO C.S.C.. Effect of HCl and HNO3 on the synthesis of pure and silver-based WO3 for improved photocatalytic activity under sunlight. Journal of Photochemistry and Photobiology A: Chemistry, v. 422, p. 1-12, 2022. DOI: 10.1016/j.jphotochem.2021.113550

    Abstract: Heterogeneous photocatalysis have been considered an important and efficient alternative water and wastewater treatment process. In this area, different semiconductors, such as tungsten trioxide, have been investigated aiming to enhance photocatalytic performance. WO3 is known to be an efficient material with high stability in acidic conditions. In the present work, pure and Ag/AgCl-doped WO3 photocatalysts were synthesized by a simple hydrothermal method. A discussion of the effects of two pH-controlling agents, HCl and HNO3, in the final properties of the catalyst is reported for the first time. The materials were characterized by XRD, BET, SEM, EDS and UV–vis DRS. All catalysts showed similar or enhanced band gap values compared to a standard photocatalyst benchmark (TiO2 P25). The type of acid did not lead to significant differences in morphology or photocatalytic activity of undoped catalysts. In contrast, doped catalysts prepared using HCl resulted in particles of flower-like morphology, with higher uniformity and slightly narrower band gap values. Furthermore, the use of HCl in the synthesis of silver-doped WO3 resulted in catalysts containing AgCl, while Ag0 was the major dopant species when HNO3 was used. All materials exhibited good photocatalytic activity, with a maximum of 75.4% acetaminophen degradation under simulated sunlight achieved by the catalyst prepared with HCl and doped with 5% Ag-equivalent. For this catalyst, the degradation kinetics was found to be consistent with the Langmuir-Hinshelwood (L−H) model, and reusability tests showed no significant decrease in the degradation efficiency after four cycles. Finally, the effects of different scavengers suggest that O2•− species play a major role in acetaminophen degradation with the material containing WO3, Ag and AgCl.

  • IPEN-DOC 28429

    CATANHEIRA, BRUNA; OTUBO, LARISSA ; OLIVEIRA, CRISTIANO L.P.; MONTES, ROSA; QUINTANA, JOSE B.; RODIL, ROSARIO; BROCHSZTAIN, SERGIO; VILAR, VITOR J.P.; TEIXEIRA, ANTONIO C.S.C.. Functionalized mesoporous silicas SBA-15 for heterogeneous photocatalysis towards CECs removal from secondary urban wastewater. Chemosphere, v. 287, Part 1, p. 1-11, 2022. DOI: 10.1016/j.chemosphere.2021.132023

    Abstract: The photocatalytic activity of TiO2 nanoparticles (NPs) supported on mesoporous silica SBA-15 (TiO2/SBA-15) was evaluated for the photodegradation of sulfadiazine (SDZ), as target contaminant of emerging concern (CEC), using either pure water solutions (PW) or a real secondary urban wastewater (UWW) spiked with SDZ. For this purpose, TiO2/SBA-15 samples with 10, 20 and 30% TiO2 (w/w) were prepared by the sol-gel post synthetic method on pre-formed SBA-15, using titanium (IV) isopropoxide as a precursor. The TiO2/SBA-15 materials were characterized by HRTEM, SAXS and XRD, nitrogen adsorption isotherms and UV–vis diffuse reflectance spectroscopy. TiO2 NPs were shown to be attached onto the external surface, decorating the SBA-15 particles. The TiO2/SBA-15 catalysts were active in SDZ photodegradation using the annular FluHelik photoreactor, when irradiated with UVA light. The 30% TiO2/SBA-15 sample presented the best performance in optimization tests performed using PW, and it was further used for the tests with UWW. The photocatalytic activity of 30% TiO2/SBA-15 was higher (56% SDZ degradation) than that of standard TiO2–P25 (32% SDZ degradation) in the removal of SDZ spiked in the UWW ([SDZ] = 2 mg L−1). The photodegradation of SDZ with 30% TiO2/SBA-15 eached 90% for UWW spiked with a lower SDZ concentration ([SDZ] = 40 μg L−1). Aside of SDZ, a suit of 65 other CECs were also identified in the UWW sample using LC-MS spectrometry. A fast-screening test showed the heterogeneous photocatalytic system was able to remove most of the detected CECs from UWW, by either adsorption and/or photocatalysis.

  • IPEN-DOC 28428

    NASCIMENTO, ERIBERTO O. do; BECATTI, MATHEUS J.P.; CALDAS, LINDA V.E. ; OLIVEIRA, LUCAS N. de . Design of Experiments (DoE) method for solar protective films via UV–Vis and NIR spectrophotometry measurements. Journal of Luminescence, v. 242, p. 1-10, 2022. DOI: 10.1016/j.jlumin.2021.118558

    Abstract: Individual dosimetry and the shielding of sun rays are needed for people in homes, at workplaces and vehicles when exposed to Ultraviolet Radiation (UVR) and/or Infrared Radiation (IR). Usually, the efficacy of Solar Protective Films (SPF) has been recognized as an important public health concern. So, this work aimed to verify, using the Design of Experiments (DoE) and Multiple Linear Regression (MLR) methods, the evaluation of solar films using the UV–Vis and NIR (Near Infrared) spectrophotometry technique for absorbance readings. In addition, the significance of the SPF manufacturing origin and glass color were evaluated. Four types of SPF, named G05, G20, G35 and WB, were tested and layered within dark and light glasses. The absorbance readings were used in a 2k factorial design analysis, then the one-way ANOVA Test and the Bonferroni Test were used to assess the statistical significance of each factor. The results showed that the statistical error, using the Root Mean Square Percentage Error (RMSPE) and the Mean Absolute Percentage Error (MAPE) methods, showed values less than 0.014% between the measured and the predicted ones, indicating excellent accuracy. In conclusion, DoE and MLR methods are suitable to be used in the investigation of the association between SPF and glass materials.

  • IPEN-DOC 28427

    DURAZZO, MICHELANGELO ; SOUZA, JOSE A.B. ; IANELLI, RICARDO F. ; TAKARA, ERIKI M. ; GARCIA NETO, JOSE S. ; SALIBA-SILVA, ADONIS M. ; CARVALHO, ELITA F.U. de . Manufacturing LEU-foil annular target in Brazil. Annals of Nuclear Energy, v. 165, p. 1-16, 2022. DOI: 10.1016/j.anucene.2021.108646

    Abstract: Molybdenum-99 is the most important isotope because its daughter isotope, technetium-99m, has been the most used medical radioisotope. The primary method used to produce Mo-99 derives from the fission of U-235 incorporated in so-called irradiation targets. Two routes are being developed to make Mo-99 by fissioning with low enriched uranium (LEU) fuel. The first adopts UAlx-Al dispersion plate targets. The second uses uranium metal foil annular targets. The significant advantage of uranium foil targets over UAlx-Al dispersion targets is the high density of uranium metal. This work presents the experience obtained in the development of the uranium metal annular target manufacturing steps. An innovative method to improve the procedure for assembling the uranium foil on the tubular target was presented. The experience attained will help the future production of Mo-99 in Brazil through the target irradiation in the Brazilian Multipurpose Reactor (RMB).

  • IPEN-DOC 28426

    GUIMARAES, LEONAM dos S.; PERROTTA, JOSE A. . Brazil looks to HALEU. Nuclear Engineering International, v. 65, n. 790, p. 22-23, 2020.

  • IPEN-DOC 28425

    CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; ALTANA, C.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHARON GARCIA, L.E.; CHAVEZ LOMELI, E.R.; CHEN, R.; CIRALDO, I.; COLONNA, M.; D'AGOSTINO, G.; DELAUNAY, F.; DESHMUKH, N.; DJAPO, H.; DE GERONIMO, G.; DE LOS RIOS, K.; FERRARESI, C.; FERREIRA, J.L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; HACISALIHOGLU, A.; HUERTA-HERNANDEZ, A.; KOTILA, Z.J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LAY, J.A.; LA FAUCI, L.; LA VIA, F.; LENSKE, H.; LINARES, R.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MAS RUIZ, J.; MEDINA, N.H.; MENDES, D.R.; MEREU, P.; MORALLES, M. ; NERI, L.; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; RIES, P.; RODRIGUES, M.R.D.; RUSSO, A.D.; RUSSO, G.; SANTOPINTO, E.; SANTOS, R.B.B.; SERBINA, L.; SGOUROS, O.; SILVEIRA, M.A.G. da; SOLAKCI, S.O.; SOULIOTIS, G.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VARGAS HERNANDEZ, H.; VSEVOLODOVNA, R.I.M.; WANG, J.S.; WERNER, V.; YANG, Y.Y.; YILDIRIN, A.; ZAGATTO, V.A.B.. Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS. Journal of Physics: Conference Series, v. 1643, p. 1-5, 2020. DOI: 10.1088/1742-6596/1643/1/012074

    Abstract: The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ). In this view measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections are performed with high-accuracy. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β-β- decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low (a few nb), being the total reaction cross section much larger (a few b), thus a high sensitivity and a large rejection capability are demanded to the experimental set-up. This limits the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is under way in order to increase the experimental dataset of more than two orders of magnitude, still preserving the high sensitivity of the present set-up. When accomplished this effort will make the INFN-LNS as the state-of-the-art research infrastructure for the systematic study of all the cases of interest for 0νββ. In this view, frontiers technologies are going to be adopted for the accelerator and the detection systems. In parallel, advanced theoretical models are being developed in order to extract the nuclear structure information from the measured cross sections.

  • IPEN-DOC 28424

    BADE, TAMIRIS G.; ROUDET, JAMES; GUICHON, JEAN-MICHEL; KUO-PENG, PATRICK; SARTORI, CARLOS A.F. . Analysis of the resonance phenomenon in unmatched power cables with the resonance surface response. Electric Power Systems Research, v. 200, p. 1-12, 2021. DOI: 10.1016/j.epsr.2021.107466

    Abstract: Power converters are an essential part of modern power systems, giving flexibility to the power transportation and allowing the insertion of a wide range of different energy sources. One drawback of the converters is that the supraharmonic conducted emissions introduced by them can compromise the stability of these systems through electromagnetic interference (EMI). Electromagnetic compatibility (EMC) filters are used to prevent such problems. Nevertheless, these filters are designed to respect standards based on measurements in conditions considerably different from real applications. Particularly, if a converter is connected to electrically long cables its conducted emissions may be amplified by the resonance phenomenon. The method described in this paper allows the definition of a range for the filters input impedances where the conducted emissions in a long cable will not be amplified beyond established levels. In some cases the method allows the visualization of three-dimensional surfaces indicating the magnitude, frequency and position of the resonance phenomenon. In the general case these surfaces are defined on higher dimensions and can be analyzed with deterministic optimization algorithms. The originality of this paper resides in the generalized analysis of the resonance phenomenon, that it is based on frequency-dependent cable parameters and applies to unbalanced systems.

  • IPEN-DOC 28423

    MERIZIO, L.G.; BONTURIM, E.; ICHIKAWA, R.U. ; SILVA, I.G.N.; TEIXEIRA, V.C.; RODRIGUES, L.C.V.; BRITO, H.F.. Toward an energy-efficient synthesis method to improve persistent luminescence of Sr2MgSi2O7:Eu2+,Dy3+ materials. Materialia, v. 20, p. 1-10, 2021. DOI: 10.1016/j.mtla.2021.101226

    Abstract: The synthesis of persistent luminescent materials usually requires a multi-step long time annealing at high temperatures (>1200°C) in a resistive oven, causing a huge energy consumption. Also, to achieve reduced oxidation states of emitter ions (e.g., Eu3+ → Eu2+ ), the H2(g) atmosphere is often used, which can be dangerous and increase the costs of the process. Therefore, the development of a quick and new single-step green strategy, using in-situ low-risk atmosphere (e.g., CO(g)) and a microwave-assisted solid-state (MASS) method has been encouraged. In this work, we present a single-step method to synthesize the compound Sr2MgSi2O7:Eu2+,Dy3+ using the MASS method and the results were compared with those prepared by a conventional ceramic method. The luminescent material was prepared in 25 min of synthesis using carbon as a microwave susceptor and CO(g) atmosphere source at the same time. A higher concentration of Eu2+ emitter was identified by XANES in the MASS method product, which has a significant effect on the luminescence efficiency, as well as an improvement in the optical properties, leading to an emission 100 times more intense. Furthermore, to understand the Eu3+ reduction process under CO(g) atmosphere, we present here the innovative results of in-situ XANES analysis for the Sr2MgSi2O7:Eu2+,Dy3+ material. Finally, the MASS method makes it possible to prepare the materials with less than 5% of the ceramic method's duration in time. The energy-saving and better-quality persistent luminescent properties obtained in the MASS method provide viable applications on anti-counterfeiting markers, solar cell sensitizers, and other luminescent technologies.

  • IPEN-DOC 28421

    CAPPARELLI, MARIANA V.; MOLINERO, JON; MOULATLET, GABRIEL M.; BARRADO, MIREN; PRADO-ALCIVAR, SANTIAGO; CABRERA, MARCELA; GIMILIANI, GIOVANA ; NACATO, CAROLINA; PINOS-VELEZ, VERONICA; CIPRIANI-AVILA, ISABEL. Microplastics in rivers and coastal waters of the province of Esmeraldas, Ecuador. Marine Pollution Bulletin, v. 173, Part B, p. 1-6, 2021. DOI: 10.1016/j.marpolbul.2021.113067

    Abstract: This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmeraldas Province, Ecuador. MPs were quantified in 14 coastal waters in beaches with different urbanization level and in 10 rivers. The most abundant MP types were transparent fibres, brown fragments, grey fragments, transparent fragments, and black fragments, which together represented 84% of the total count. Coastal waters presented significantly higher quantities of MP than rivers. No difference in microplastic abundance was detected between beaches with higher and lower urban occupation, nor between beaches facing North or West. Our results indicate that MP contamination is widespread, and most likely transported from multiple sources. Our results can serve as a baseline for future MP monitoring in the area.

  • IPEN-DOC 28422

    AMARAL, MARCELO P.; COIRADA, FERNANDA C.; APOSTOLICO, JULIANA de S.; TOMITA, NADIA; FERNANDES, EDGAR R.; SOUZA, HIGO F.S.; CHURA-CHAMBI, ROSA M. ; MORGANTI, LIGIA ; BOSCARDIN, SILVIA B.; ROSA, DANIELA S.. Prime-boost with Chikungunya virus E2 envelope protein combined with Poly (I:C) induces specific humoral and cellular immune responses. Current Research in Immunology, v. 2, p. 23-31, 2021. DOI: 10.1016/j.crimmu.2021.03.001

    Abstract: Chikungunya virus (CHIKV) is an arbovirus transmitted to humans mainly by the bite of infected Aedes aegypti and Aedes albopictus mosquitoes. CHIKV illness is characterized by fever and long-lasting arthritic symptoms, and in some cases it is a deadly disease. The CHIKV envelope E2 (E2CHIKV) glycoprotein is crucial for virus attachment to the cell. Furthermore, E2CHIKV is the immunodominant protein and the main target of neutralizing antibodies. To date, there is no available prophylactic vaccine or specific treatment against CHIKV infection. Here, we designed and produced a DNA vaccine and a recombinant protein containing a consensus sequence of E2CHIKV. C57BL/6 mice immunized twice with the E2CHIKV recombinant protein in the presence of the adjuvant Poly (I:C) induced the highest E2CHIKV-specific humoral and cellular immune responses, while the immunization with the homologous DNA vaccine pVAX-E2CHIKV was able to induce specific IFN-γ producing cells. The heterologous prime-boost strategy was also able to induce specific cellular and humoral immune responses that were, in general, lower than the responses induced by the homologous E2CHIKV recombinant protein immunization. Furthermore, recombinant E2CHIKV induced the highest titers of neutralizing antibodies. Collectively, we believe this is the first report to analyze E2CHIKV-specific humoral and cellular immune responses after immunization with E2CHIKV recombinant protein and DNA pVAX-E2CHIKV vaccine platforms.

  • IPEN-DOC 28420

    OLIVO-ARIAS, L.P.; ARAUJO, L.G. . Three-dimensional transient numerical simulation of the solid volume fraction of a fluidized bed: the role of three solution orders using a discretization scheme. Latin American Journal of Physics Education, v. 15, n. 2, p. 2303-1 - 2303-10, 2021.

    Abstract: The FLUENT solver employed in the Computational Fluid Dynamics (CFD) has been extensively developed to extend its robustness and precision for a wide range of flow regimes. For that, the FLUENT solver has a numerical method in the pressure-based solver that has traditionally been used for incompressible and slightly compressible flows. The algorithm is based on the pressure that solves the equations in a segregated or decoupled mode. This algorithm has proven to be robust and versatile and has been used cooperatively with a wide range of physical models, including multiphase flows and conjugated heat transfer. However, there are applications in which the convergence rate of the segregated algorithm is not satisfactory, generally due to the need in these coupling scenarios between the continuity and momentum equations. The objective of this article is to validate the Eulerian model to determine the volumetric fractions of the solid phase fraction. For this, we used data from the literature and the PCSIMPLE algorithm (solver) at different orders of solution of the continuity, momentum, and turbulence equations. Also, we determined its efficiency in transient systems and how it would affect the results in the hydrodynamics of a three-phase fluidized bed reactor. The results were significant, thus representing the phenomenon of interaction between the liquid-solid and solid-gas phases.

  • IPEN-DOC 28419

    OLIVO-ARIAS, L.P.; ARAUJO, L.G. . The influence of the initial gas distribution on the dynamics of a three-phase fluidized bed reactor: non-ideal gas condition. Latin American Journal of Physics Education, v. 15, n. 1, p. 1312-1 - 1312-6, 2021.

    Abstract: The hydrodynamic evolution of a three-dimensional (3D) liquid-gas-solid fluidized bed reactor was studied using computational fluid dynamics (CFD) simulations, and the results were compared with previous experimental data. The gas-solid and liquid-solid interactions were calculated using the Euler-Euler model, incorporating the kinetic theory for the solid phase. The momentum exchange coefficients for the fluid-solid interactions were calculated using the Gidaspow drag model, and the fluid-fluid interactions by using the Schiller-Naumann model. The predicted gas volume fraction agreed to the Kumar model and showed better performance with the use of higher-order discretization. Furthermore, the Peng Robinson thermodynamic correlation was used to determine the properties of the materials under high severity conditions. The results showed a consistent distribution of the phases, it was quite uniform and there was a reasonable expansion of the bed when gas injection was established as an initial condition.

  • IPEN-DOC 28418

    IMAMURA, MARTA; MIRISOLA, ALINE R.; RIBEIRO, FERNANDO de Q.; DE PRETTO, LUCAS R. ; ALFIERI, FABIO M.; DELGADO, VINICIUS R.; BATTISTELLA, LINAMARA R.. Rehabilitation of patients after COVID-19 recovery: an experience at the Physical and Rehabilitation Medicine Institute and Lucy Montoro Rehabilitation Institute. Clinics, v. 76, p. 1-9, 2021. DOI: 10.6061/clinics/2021/e2804

    Abstract: OBJECTIVES: As patients recovering from the novel coronavirus disease 2019 (COVID-19) present with physical, respiratory, cognitive, nutritional, and swallowing-related impairments and mental health complications, their rehabilitation needs are complex. This study aimed to describe the demographic, clinical, and functional status after the discharge of COVID-19 survivors who underwent intensive multidisciplinary inpatient rehabilitation at the Physical and Rehabilitation Medicine Institute of the University of Sao Paulo Medical School General Hospital and Lucy Montoro Rehabilitation Institute. We determined the most important factors related to the length of inpatient rehabilitation treatment and present the functional outcomes. METHODS: This was a retrospective study based on electronic medical records. In addition to the severity of COVID-19 and length of hospital stay for the management of COVID-19 and comorbidities, we collected sociodemographic data including age, sex, height, and weight. Functional assessments were performed using the Functional Independence Measure (FIM); Short Physical Performance Battery; Montreal Cognitive Assessment; Depression, Anxiety and Stress Scale; Revised Impact of Events Scale; bioelectrical impedance; Functional Oral Intake Scale; oropharyngeal dysphagia classification; and nutritional assessment. RESULTS: There was a significant improvement in FIM before and after inpatient rehabilitation treatment (p<0.0001). Muscle strength and walking capacity were significantly improved (p<0.01). The most important factors related to the length of inpatient rehabilitation treatment were improvement in FIM scores (Spearman’s r=0.71) and gain in lean mass (Spearman’s r=0.79). CONCLUSIONS: Rehabilitation of patients after COVID-19 recovery improves their functional status and should be considered in the post-acute phase for selected patients with COVID-19.

  • IPEN-DOC 28417

    SOUZA, MARCIELLI K.R. de; CARDOSO, EDUARDO dos S.F.; FORTUNATO, GUILHERME V.; LANZA, MARCOS R.V.; NAZARIO, CARLOS E.; ZANONI, MARIA V.B.; MAIA, GILBERTO; CARDOSO, JULIANO C. . Combination of Cu-Pt-Pd nanoparticles supported on graphene nanoribbons decorating the surface of TiO2 nanotube applied for CO2 photoelectrochemical reduction. Journal of Environmental Chemical Engineering, v. 9, n. 4, p. 1-11, 2021. DOI: 10.1016/j.jece.2021.105803

    Abstract: The photoelectrocatalysis (PEC) technique was applied in CO2 reduction using different proportions of Cu, Pd, and Pt supported on graphene nanoribbons (GNR) and deposited on the surfaces of TiO2 nanotubes. Altogether, nine combinations of TiO2-NT/GNR-metal were assembled, although only three of them efficiently promoted the generation of methanol and ethanol in high quantities. Comparison with the photocatalysis, photolysis, and electrocatalysis techniques showed the extremely high efficiency of PEC, which enabled production of methanol and ethanol at levels around 19.2-fold and 44.4-fold higher, respectively, than photocatalysis, the second most efficient technique. The presence of metallic nanoparticles in the system facilitated CO2 reduction due to the trapping of the photogenerated electrons, prolonging their lifetime, lowering the reaction energy barrier for CO2 reduction, and provided active intermediates. Therefore, the assembly of these materials containing low amounts of metals is highly promising, since it can assist in alleviating environmental problems caused by CO2 emissions, while at the same time enabling the energetically efficient generation of compounds of commercial value.

  • IPEN-DOC 28416

    BALIEIRO, L.M. ; OLIVEIRA, H.B. ; TEIXEIRA, L.F.S. ; BELLINI, M.H. ; MATSUDA, M.M.N. ; ARAUJO, E.B. . Study of the automated synthesis of the radiopharmaceutical [18F]fluoroestradiol. Brazilian Journal of Radiation Sciences, v. 9, n. 3, p. 1-18, 2021. DOI: 10.15392/bjrs.v9i3.1709

    Abstract: Breast cancer is the second leading cause of cancer death among women worldwide, with an incidence increase of 25 % per year. Approximately 75 % of breast cancer cells express estrogen receptors. The 16α-[18F]fluoro-17β-estradiol, [18F]FES, is a radiopharmaceutical that binds to estrogen receptors applied in PET-CT molecular images for non-invasive diagnosis of primary and metastatic breast cancer. The objective of this work was to study the synthesis of the [18F]FES in the GE TRACERlab® MXFDG module, using the Chemical Kit and the ABX® disposable cassette. Moreover, to determine the process yield and the analytical parameters to be used in the routine production of this radiopharmaceutical. Automated synthesis took place in 75 minutes and included percolation of [18F]fluoride (18F-) in an anion exchange cartridge, elution of the cartridge, azeotropic drying in 3 steps, labeling of the precursor 3-methoxymethyl-16β,17β-epiestriol-O-cyclic sulfone (MMSE) and a hydrolysis step. The product was purified in the module by solid-phase extraction (SPE) cartridges. The radiochemical yield was reproductive, despite initial [18F]fluorine activity, and the results of quality control tests suggest that the radiopharmaceutical meets the acceptance criteria established in official monographs for other radiopharmaceuticals labeled with 18-fluor. In vivo biodistribution studies in healthy mice and mice bearing MCF7 tumors showed the specific uptake on breast tumor cells.

  • IPEN-DOC 28415

    PANZARINI, LUZ C.G.A. ; MORANDIM-GIANNETTI, ANDREIA de A.; GUEDES, SELMA M.L. . Manufacture of non-thrombogenic polymer surfaces by gamma irradiation to induce simultaneous grafting and heparinization of thin PVC films. Journal of Bioactive and Compatible Polymers, v. 36, n. 4, p. 283-295, 2021. DOI: 10.1177/08839115211030634

    Abstract: Investigations regarding alternative methods for producing polymeric materials with hydrophilic properties have increased considerably. In this context, polymeric biomaterials with hemocompatible surface properties have been successfully obtained by grafting hydrophilic monomers onto commercial polymer films by simultaneous irradiation processes. In this study, simultaneous irradiation and grafting were used to produce a copolymer PVC-co-DMAEMA-co-heparin with hemocompatible surface properties. Characterization by FTIR of the graft copolymer indicates that the increase in monomer grafting levels inhibits the bonding sites to heparin. FTIR-PAS analyses of the graft copolymers showed that the highest graft levels were obtained for the irradiated samples containing 45% of monomer. Heparin, however, could only be detected in the irradiated samples containing 30% of DMAEMA. The analysis of the micrographs, on the other hand, showed that increasing the monomer concentration enhances surface roughness of the graft copolymers. Roughness however decreased with heparin addition. It was possible to verify that an excess of surface roughness of the graft copolymers inhibits anticoagulant properties of heparin, triggering thrombus formation. Platelet adhesion, on its turn, was not significantly affected by the presence of heparin when PVC-co-DMAEMA and PVC-co-DMAEMA-co-heparin, obtained from the systems containing 45% of monomer, are compared. The addition of heparin in the systems containing 30% of DMAEMA resulted in fewer thrombogenic surfaces.

  • IPEN-DOC 28414

    LINI, RENATA S.; AGUERA, RAUL G.; HOELTGEBAUM, DANIELLE; PANIZ, FERNANDA P.; PEDRON, TATIANA; CAPELARI, SILVIA; MONTEIRO, LUCILENA R. ; MACHINSKI JUNIOR, MIGUEL; NERILO, SAMUEL B.; BATISTA, BRUNO L.; OLIVEIRA, MAGDA L.F. de; MOSSINI, SIMONE A.G.. Elemental plasma content and urinary excretion in vineyard farmers occupationally exposed to pesticides in southern Brazil. Environmental Science and Pollution Research, v. 28, n. 37, p. 51841-51853, 2021. DOI: 10.1007/s11356-021-14384-6

    Abstract: This is a cross-sectional study with data and biological material collection from vineyard farmers in southern Brazil. An interview was carried out through a questionnaire developed according to the reference guide of the state government. Plasma and urine samples were screened for Aluminum, Chromium, Manganese, Copper, Nickel, Cobalt, Zinc, Arsenic, Selenium, Cadmium, Antimony, Barium, Mercury, Lead and Uranium, with a technique for fast determination of these elemental contents in biological material utilizing dynamic reaction cell inductively coupled mass spectrometry. Principal component analysis was used to identify associations between these elemental contents in biological samples and the information obtained from the interviews. The farmers showed some trace elements in plasma and urine at a higher concentration than unexposed populations from other studies. This study highlights recent findings of trace elements in biological material and their association with characteristics of pesticide use. In addition, it also contributes to the gap in the literature regarding trace elements content in plasma and urine of workers exposed to pesticides.

  • IPEN-DOC 28413

    XAVIER FILHO, JOEL M. ; SILVEIRA, I.S. ; CALDAS, L.V.E. . Radiology and mammography standard X-ray spectra simulated with the Monte Carlo method. Brazilian Journal of Radiation Sciences, v. 9, n. 2C, p. 1-13, 2021. DOI: 10.15392/bjrs.v9i2C.1670

    Abstract: Six standard beams described in the TRS-457 (IAEA): RQR 5, 8, M1, M2, M3, M4 were simulated using the EGSnrc Monte Carlo code. Each spectrum was created by an X-ray tube simulated in BEAMnrc, and attenuation curves were obtained using the application egs_kerma. The quality of each beam was evaluated by the 1st and 2nd half-value layers, the homogeneity coefficients and the mean energies. All beams presented quality parameters compatible with those described in TRS-457 (IAEA).

  • IPEN-DOC 28412

    PELOSI, A.G.; SANTOS, S.N.C.; DIPOLD, J. ; ANDRADE, M.B.; HERNANDES, A.C.; ALMEIDA, J.M.P.; MENDONCA, C.R.. Effects of modifier oxides in the nonlinear refractive index of niobium-borotellurite glasses. Journal of Alloys and Compounds, v. 878, p. 1-8, 2021. DOI: 10.1016/j.jallcom.2021.160382

    Abstract: This work investigates the influence of transition metals oxides (Ta2O5 and ZrO2) on the nonlinear refraction of niobium-borotellurite glasses prepared by melt-quenching technique. The closed-aperture Z-scan technique was used to measure the nonlinear refractive index (n2) spectrum from 470 nm to 800 nm. Also, the BGO (Boling, Glass, and Owyoung) approach was used to model nonlinear spectra, considering the oxygens present in the sample as the major contribution to the nonlinearity. The samples’ molar electronic polarizability was determined to further understanding the effect of the transition metals oxides on the optical properties. Structural analysis was performed by differential scanning calorimetry, Raman and Infrared spectroscopies. The results indicate that although the modifier oxides affect the structural units and glass polarizability, they are not enough to change the behavior of the nonlinear refractive index spectra, being the glass-matrix the main responsible for optical nonlinearity in the system studied here.

  • IPEN-DOC 28411

    PRADO, EDUARDO S.P. ; MIRANDA, FELIPE de S.; RITA, CRISTIAN C.P.; SILVA, ROBERSON J. da; ESSIPTCHOUK, ALEXEI M.; PETRACONI FILHO, GILBERTO; BALDAN, MAURICIO R.; POTIENS JUNIOR, ADEMAR J. . Estudo do processamento de rejeitos radioativos sólidos compactáveis por plasma térmico / Study of compactable solid radioactive waste processing by thermal plasma. Brazilian Applied Science Review, v. 5, n. 4, p. 1795-1807, 2021. DOI: 10.34115/basrv5n4-005

    Abstract: O uso de radioisótopos para as mais diversas finalidades tem se intensificado e destacado pelos benefícios que proporcionam. A geração de energia elétrica, a indústria, a agricultura, a medicina diagnóstica e terapêutica, são alguns exemplos. Porém, essas aplicações têm como desvantagem gerar rejeitos radioativos e estes requerem tratamento apropriado para deposição final. Neste âmbito, entre as tecnologias promissoras para o tratamento de rejeitos radioativos sólidos compactáveis, a utilização de plasma térmico para gerar uma descarga de arco transferido por meio de eletrodos de grafite se mostra uma tecnologia capaz de reduzir substancialmente a massa e o volume de rejeitos radioativos após expô-los a temperaturas superiores a 3.000ºC. Os resultados obtidos se mostraram bastante satisfatórios, alcançando aproximadamente 100% de redução em 30 min de processo. Esforços futuros devem ser empregados para maior confiabilidade do sistema, eliminação de radionuclídeos voláteis no efluente gasoso e otimização completa da operação.

  • IPEN-DOC 28410

    SILVA, MATHEUS S.; TAVARES, ANA P.M.; COELHO, LUIZ F.L.; DIAS, LIGIA E.M.F. ; CHURA-CHAMBI, ROSA M. ; FONSECA, FLAVIO G. da; SALES, MARIA G.F.; FIGUEIREDO, EDUARDO C.. Rational selection of hidden epitopes for a molecularly imprinted electrochemical sensor in the recognition of heat-denatured dengue NS1 protein. Biosensors and Bioelectronics, v. 191, p. 1-8, 2021. DOI: 10.1016/j.bios.2021.113419

    Abstract: Rational selection of predicted peptides to be employed as templates in molecular imprinting was carried out for the heat-denatured non-structural protein 1 (NS1) of dengue virus (DENV). Conservation analysis among 301 sequences of Brazilian isolates of DENV and zika virus (ZIKV) NS1 was carried out by UniProtKB, and peptide selection was based on in silico data of the conservational, structural and immunogenic properties of the sequences. The selected peptide (from dengue 1 NS1) was synthesized and employed as a template in the electropolymerization of polyaminophenol-imprinted films on the surface of carbon screen-printed electrodes. Heat denaturation of the protein was carried out prior to analysis, in order to expose its internal hidden epitopes. After removal of the template, the molecularly imprinted cavities were able to rebind to the whole denatured protein as determined by electrochemical impedance spectroscopy. This label-free sensor was efficient to distinguish the NS1 of DENV from the NS1 of ZIKV. Additionally, the sensor was also selective for dengue NS1, in comparison with human serum immunoglobulin G and human serum albumin. Additionally, the device was able to detect the DENV NS1 at concentrations from 50 to 200 μg L−1 (RSD below 5.04%, r = 0.9678) in diluted human serum samples. The calculated LOD and LOQ were, respectively, 29.3 and 88.7 μg L−1 and each sensor could be used for six sequential cycles with the same performance.

  • IPEN-DOC 28409

    MONTEIRO, LUCILENA R. ; TERZER-WASSMUTH, STEFAN; MATIATOS, IOANNIS; DOUENCE, CEDRIC; WASSENAAR, LEONARD I.. Distinguishing in-cloud and below-cloud short and distal N-sources from high-temporal resolution seasonal nitrate and ammonium deposition in Vienna, Austria. Atmospheric Environment, v. 266, p. 1-11, 2021. DOI: 10.1016/j.atmosenv.2021.118740

    Abstract: Reactive nitrogen (Nr: nitrate and ammonium) washout in Vienna (Austria) precipitation events were investigated in 2019. A total of 958 samples from 61 rain events representing >90% of annual precipitation were collected at 5–30 min intervals for nitrate (NO3−) and ammonium (NH4+) analyses and meteorological information. The data revealed systematic seasonal concentration variations for all Nr-species and a clear influence of rush-hour traffic on the kinetics of N-scavenging processes. The monthly nitrate and ammonium deposition was 0.69 ± 0.21 kg ha−1 month−1 and 1.02 ± 0.30 kg ha−1 month−1, respectively. Around 30% of nitrate and 20% of ammonium was dry deposition, and ∼30% of each N-species was from distal sources associated with rainout processes. The half-life of below-cloud N-species were similar in the warmer seasons (1.7 ± 0.2 h and 2.3 ± 0.4 h for nitrate and ammonium). In winter, the ammonium half-life was significantly lower (1.4 h). Nr removal by wet-only in-cloud scavenging was slower than predicted by empirical models. HYSPLIT trajectory analysis revealed that Nr rainout from distal sources in spring had no prevailing direction, but higher Nr contributions were from N and W. In summer and winter, air masses from W, SW and SE were related to intense, medium, and low Nr contributions, respectively. The origin and path of these trajectories coincided with known NOx hotspots in Europe.

  • IPEN-DOC 28408

    HONEGGER, V.; SEO, E.S.M. ; MIRANDA, L.F.; BARBOSA, I.T.F.. Pseudoboehmite nanocarriers in cosmetic formulations. International Journal of Development Research, v. 11, n. 6, p. 47735-47738, 2021. DOI: 10.37118/ijdr.22018.06.2021

    Abstract: The aim of this study is to contribute to the preparation and characterization of nanoemulsions for anti-aging cosmetic use. Palmarosa oil and Rosehip nanoemulsions were prepared with different active cosmetic ingredients such as mandelic acid and hyaluronic acid, in concentrations of 1%, 3% and 5% (wt%) of pseudoboehmite. After the nanoemulsions analysis, they were characterized in the following parameters: visual analysis, pH, density and optical microscopy. The results obtained show the possibility of using different compositions, the most suitable were: palmarosa oil nanoemulsion with 3 or 5wt% of mandellic acid/pseudoboehmite and palmarosa oil nanoemulsion with 1,3 or 5% of hyaluronic acid/pseudobohemite.

  • IPEN-DOC 28407

    SEO, EMILIA S.M. ; BARBOSA, ISABELLA T.F.; ATHIE, ALESSANDRO A.R.; LUCA, ADRIANO C. de. Obtaining and characterization of polymeric composites reinforced with natural fibers. International Journal of Development Research, v. 11, n. 10, p. 50900-50903, 2021. DOI: 10.37118/ijdr.23135.10.2021

    Abstract: Currently, human activities cause impacts on the environment, and the generation of waste is a major concern. Among different residues will be agro-industrial residues, particularly residues of sugarcane bagasse and green coconut shell. Such chemically treated waste was reused as a polymer matrix reinforcement. In this sense, the present work aims to obtain and characterize polymeric composites reinforced with these natural fibers from green sugarcane bagasse and green coconut shell. The natural fibers were obtained by mercerization process, using sodium hydroxide and acetic acid in the optimized concentrations, washed in distilled water, dried, crushed and classified. By injection process, a polymeric composite made of high density polyethylene and different mass concentrations of natural fibers was obtained in a glass production matrix. The product obtained was characterized by a tensile test, verifying that the maximum tension obtained was 24.5 MPa for the concentrations of 3% and 5% (% wt) of natural fibers. In the compressive strength test, the sugarcane fibers showed greater tensile strength of 792.625 Kgf ± 73.873 at 5 (% wt) of fiber used, while for the higher coconut fibers, the tensile strength of 925,000 Kgf ± 12.832 at 3 (% wt) of fiber.

  • IPEN-DOC 28406

    PRADO, E.S.P. ; MIRANDA, F.S.; ARAUJO, L.G. ; PETRACONI, G.; BALDAN, M.R.; ESSIPTCHOUK, A.; POTIENS JUNIOR, A.J. . Experimental study on treatment of simulated radioactive waste by thermal plasma: temporal evaluation of stable Co and Cs. Annals of Nuclear Energy, v. 160, p. 1-6, 2021. DOI: 10.1016/j.anucene.2021.108433

    Abstract: Thermal plasma technology is a process that demonstrates high performance for the processing of different types of waste. This technology can also be applied in the treatment of radioactive wastes, which requires special care. Beyond that, volumetric reduction, inertization, as well as a cheap and efficient process are necessary. In this context, the purpose of this paper is to demonstrate the application of thermal plasma technology for the treatment of solid radioactive waste. For this, stable Co and Cs were used to simulate compactable and non-compactable radioactive waste; about 0.8 g Co and 0.6 g Cs were added in each experimental test. The experimental tests were conducted using plasma of transferred arc electric discharge generated by the graphite electrode inside the process reactor. The behavior and distribution of the radionuclides present in the waste were assessed during the plasma process. The results show that the significant amounts of Co and Cs leave the melt by volatilization and are transferred to the gas phase with a small portion retained in the molten slag. The retention rate of Co in the slag phase is about 0.03% and 0.30% for compactable and non-compactable waste, respectively. On the other hand, Cs is completely transferred to the gas phase when added to the compactable waste. Conversely, when in the non-compactable waste, only 1.4% Cs is retained.

  • IPEN-DOC 28405

    MARTINS, ANA P.G.; RIBEIRO, ANDREZA P.; FERREIRA, MAURICIO L.; MARTINS, MARCO A.G.; NEGRI, ELNARA M.; SCAPIN, MARCOS A. ; OLIVEIRA, ANDERSON de; SAIKI, MITIKO ; SALDIVA, PAULO H.N.; LAFORTEZZA, RAFFALE. Infraestrutura verde para monitorar e minimizar os impactos da poluição atmosférica. Estudos Avançados, v. 35, n. 102, p. 31-57, 2021. DOI: 10.1590/s0103-4014.2021.35102.003

    Abstract: O Material Particulado (MP) está entre os principais contaminantes do ar. A Infraestrutura Verde (IV) vem sendo reconhecida como alternativa para melhorar a qualidade do ar. As árvores podem afetar diretamente os níveis de MP, interceptando partículas em sua superfície. Devido a essa capacidade, esta pesquisa teve como objetivo contribuir com informações sobre a viabilidade da vegetação verde para interceptar e identificar as principais fontes de poluentes atmosféricos. Amostras de cascas de árvores de parques urbanos de São Paulo (SP) foram utilizadas como monitor biológico de poluentes atmosféricos. Foi observado um decaimento exponencial das concentrações e aprisionamento de poluentes em direção à região mais interna dos parques. Além disso, foi possível distinguir a emissão de veículos leves das emissões de veículos pesados. O baixo custo do monitoramento e sua eficácia mostram que a IV ocupa papel de destaque na melhoria da saúde e a qualidade de vida das pessoas, bem como nas ações que buscam atenuar os efeitos da poluição do ar em cidades de médio e grande porte.

  • IPEN-DOC 28404

    SENIWAL, BALJEET; THIPE, VELAPHI C. ; SINGH, SUKHVIR; FONSECA, TELMA C.F.; FREITAS, LUCAS F. de . Recent advances in brachytherapy using radioactive nanoparticles: an alternative to seed-based brachytherapy. Frontiers in Oncology, v. 11, p. 1-24, 2021. DOI: 10.3389/fonc.2021.766407

    Abstract: Interstitial brachytherapy (BT) is generally used for the treatment of well-confined solid tumors. One example of this is in the treatment of prostate tumors by permanent placement of radioactive seeds within the prostate gland, where low doses of radiation are delivered for several months. However, successful implementation of this technique is hampered due to several posttreatment adverse effects or symptoms and operational and logistical complications associated with it. Recently, with the advancements in nanotechnology, radioactive nanoparticles (radio-NPs) functionalized with tumor-specific biomolecules, injected intratumorally, have been reported as an alternative to seed-based BT. Successful treatment of solid tumors using radio-NPs has been reported in several preclinical studies, on both mice and canine models. In this article, we review the recent advancements in the synthesis and use of radio-NPs as a substitute to seed-based BT. Here, we discuss the limitations of current seed-based BT and advantages of radio-NPs for BT applications. Recent progress on the types of radio-NPs, their features, synthesis methods, and delivery techniques are discussed. The last part of the review focuses on the currently used dosimetry protocols and studies on the dosimetry of nanobrachytherapy applications using radio-NPs. The current challenges and future research directions on the role of radio-NPs in BT treatments are also discussed.

  • IPEN-DOC 28403

    VILELA JUNIOR, RAFAEL de A.; ARANHA, LUIS C. ; ELIAS, CARLOS N.; MARTINEZ, ELIZABETH F.. In vitro analysis of prosthetic abutment and angulable frictional implant interface adaptation: mechanical and microbiological study. Journal of Biomechanics, v. 128, p. 1-6, 2021. DOI: 10.1016/j.jbiomech.2021.110733

    Abstract: The aim of this study was to evaluate, in vitro, the microbiological sealing at the implant and different angles frictional prosthetic abutment interface, submitted or not to mechanical cycling, as well as the deactivation force and evaluation of the implant-abutment interface by scanning electron microscopy. For this study, the sealing capacity of eighty sets of abutments/implants of each angle, with and without mechanical cycling, with internal conical connection (locking tapper) (4.3 mm × 9.0 mm) constituted in Titanium alloy (Ti6Al4V), and stainless steel angled prosthetic abutment was evaluated (18Cr14Ni2.5Mo) according to ASTM F138-13a (Arcsys, FGM, Joinville, Brazil), 6 mm high and 4.2 mm in diameter at the coronary portion, and 3.5 mm high transmucosal, in 4 different angles (0, 5, 10 and 20°). After in vitro tests, 100% biological sealing was observed at the implant / prosthetic abutment interface within cycled and non-cycled conditions, for the straight, 5, 10 and 20° inclination groups. There was no statistically significant difference in the removal force of the prosthetic abutments at different angles, under non-cycled conditions; however, under mechanical loading, the deactivation force was significantly higher for straight prosthetic abutments than with 10 and 20° of angulation. Surface analysis revealed good adaptation between implants and abutments, and the presence of wear areas, independently of mechanical loading. It is concluded that the analysis of implant and prosthetic abutment interface revealed good adaptation between the parts, for all analyzed samples.

  • IPEN-DOC 28402

    GUZMAN, JHOAN; NOBRE, RAFAEL de M.; JUNIOR, RODRIGUES D.L.; MORAIS, WILLY A. de; NUNUES, ENZO R.; BAYERLEIN, D.L. ; FALCAO, R.B.; SALLICA-LEVA, EDWIN; OLIVEIRA, HENRIQUE R.; CHASTINET, VICTOR L.; LANDGRAF, FERNANDO J.G.. Comparing spherical and irregularly shaped powders in laser powder bed fusion of Nb47Ti alloy. Journal of Materials Engineering and Performance, v. 30, n. 9, SI, p. 6557–6567, 2021. DOI: 10.1007/s11665-021-05916-9

    Abstract: Literature reports that irregularly shaped powder has lower flowability and apparent density than spherical shaped powder, factors that hinder its use in additive manufacturing, although its cost is potentially lower. In this study, four samples of Nb47Ti alloy manufactured by laser powder bed fusion from plasma atomized (PA) and hydride–dehydride (HDH) powders with different scanning strategies and interstitial element content were compared. Laser power levels of 200 W and 300 W were investigated. To keep a constant powder mass under the laser beam, the processing table displacement for samples from the HDH powder was twice larger than the 30 µm used for samples from the PA powder procedure, due to the lower apparent density of the HDH powder. It was possible to achieve porosity levels below 1% with both powders. However, the power of 200 W generated 13% of porosity in the HDH samples. A similar microstructure formed by melt pools and cellular dendritic structure in a β phase matrix of body-centered cubic (BCC) structure was obtained in all samples. Furthermore, the low interstitial element content of samples from PA powder resulted in lower microhardness when compared to the higher interstitial element content of samples from HDH powder.

    Palavras-Chave: microstructure; hydrides; porosity; powders; additives; manufacturing

  • IPEN-DOC 28401

    MACEDO, FERNANDA de M. ; CORREA, THAIS ; ARAUJO, ELAINE C. ; ANDRADE, IZABEL da S. ; GUARDANI, ROBERTO; VESELOVSKII, IGOR; LANDULFO, EDUARDO . Methane detection in the lower troposphere related to the burning of biomass and leakage in a petrochemical pole, using Raman lidar technique / Detecção de metano em baixa troposfera relacionada à queima de biomassa e gases fugitivos em pólo petroquímico, utilizando a técnica de raman lidar. Holos Environment, v. 21, n. 1, p. 138-152, 2021. DOI: 10.14295/holos.v21i1.12425

    Abstract: Fugitive emissions, defined as unintended or irregular leaks of gases and vapors, are an important source of pollutants to the atmosphere, which is difficult to monitor and control. These sources are present in different sites, especially in regions that are growing in size and economic activity. In this study, we present the results of the capability to detect methane profiles at low troposphere combining data retrieval correlations between a rotacional/vibracional Raman lidar (RVRL) and a cavity ring-down spectrometer (CRDS). The measurements were made at two different sites, metropolitan area of São Paulo (MSP) and industrial area of Cubatão (IC). The lidar is based on a tripled Nd:YAG laser with a 20 Hz repetition rate, operating on the 355 nm wavelength elastic channel, the 353 nm and 396 nm wavelength inelastic channels. A measurement protocol was established, considering acquisition time for signal accumulation, climatic conditions and data above and below the planetary boundary layer. The idea was to establish specific measurement procedures for situations related to product leakage in the oil process and natural events, such as biomass burning. With over 150 hours of data acquisition, the results pointed the possibility of analyzing data from distances up to 1500 m with an initial resolution of 7.5 m which was extended to 100 - 300 m after data smoothing for obtaining final results. The concentration was calculated from the ratio between the methane Raman backscatter signal and the nitrogen signal, at 396 nm and 353 nm, respectively. The temporal variation of methane concentrations was correlated with CRDS data, in order to obtain a first degree calibration.

    Palavras-Chave: methane; detection; optical radar; greenhouse gases; remote sensing; raman spectra

  • IPEN-DOC 28367

    BIANCOLLI, ANA L.G. ; BARBOSA, ANDREY S. ; KODAMA, YASKO ; SOUZA JUNIOR, ROGERIO R. de; LANFREDI, ALEXANDRE J.C.; FONSECA, FABIO C. ; REY, JOSE F.Q.; SANTIAGO, ELISABETE I. . Unveiling the influence of radiation-induced grafting methods on the properties of polyethylene-based anion-exchange membranes for alkaline fuel cells. Journal of Power Sources, v. 512, p. 1-12, 2021. DOI: 10.1016/j.jpowsour.2021.230484

    Abstract: Anion-exchange membranes (AEM) are envisioned as the enabling materials for the widespread use of cost-effective and efficient polymeric fuel cells. Advancing the understanding of the effect of radiation-induced grafting (RIG) method on the final properties of AEMs is crucial to boost the performance of anion-exchange membrane fuel cells (AEMFCs). The present study provides a systematic investigation of the effect of RIG methods on physicochemical properties of LDPE-based AEMs with similar degree of grafting (DoG) and ion exchange capacity (IEC). Samples grafted by two methods − pre-irradiation (PIM) and simultaneous (SM) − have the same molecular structure, but distinct physicochemical properties due to markedly differences in the degree of crosslinking. Detailed characterization of AEMs showed that RIG method determines the mechanical properties, water transport, and the distribution of ionic groups, which have a direct impact on fuel cell performance and durability. The discussed results show that grafting step directly influences the internal structure and morphology. Controlling the synthesis parameters during RIG is a key feature to design AEMs with enhanced properties that lead to high AEMFC performance and stability.

    Palavras-Chave: ion exchange; anions; membranes; fuel cells; irradiation

  • IPEN-DOC 28366

    CABRAL, FERNANDA V. ; SOUZA, TIAGO H. dos S.; SELLERA, FABIO P.; FONTES, ADRIANA; RIBEIRO, MARTHA S. . Towards effective cutaneous leishmaniasis treatment with light-based technologies. A systematic review and meta-analysis of preclinical studies. Journal of Photochemistry and Photobiology B: Biology, v. 221, p. 1-8, 2021. DOI: 10.1016/j.jphotobiol.2021.112236

    Abstract: Cutaneous leishmaniasis (CL) is a neglected disease that represents a serious global public health concern. We performed a systematic review with meta-analysis targeting the use of light-based therapies on CL in preclinical studies since they are essential to identify the benefits, challenges, and limitations of proposing new technologies to fight CL. We searched Pubmed and Web of Science to include original preclinical researches in English that used light-based technologies to fight CL. Inclusion criteria encompassed any animal model for CL induction, an untreated infected group as the comparator, reliable and consistent methodology to develop and treat CL, focus on an antimicrobial therapeutic approach, and data for lesion size and/or parasite load in the infection site. We identified eight eligible articles, and all of them used photodynamic therapy (PDT). For the meta-analysis, three studies were included regarding the parasite load in the infection site and four comprised the lesion size. No overall statistically significant differences were observed between untreated control and PDT groups for parasite load. Differently, PDT significantly reduced the lesion size regardless of the protocol used to treat CL (in mm, SMD: -1.90; 95% CI: −3.74 to −0.07, p = 0.04). This finding is particularly encouraging since CL promotes disfiguring lesions that profoundly affect the quality of life of patients. We conclude that PDT is a new promising technology able to be topically used against CL if applied in more than one session, making it a promising ally for the management of CL.

    Palavras-Chave: protozoa; antimicrobial agents; therapy; photosensitivity

  • IPEN-DOC 28365

    PANESI, A.R.Q. ; SILVA, R.P. ; CUNHA, E.F. ; KORKISCHKO, I. ; SANTIAGO, E.I. . Three-dimensional CFD modeling of H2/O2 HT-PEMFC based on H3PO4-doped PBI membranes. Ionics, v. 27, n. 8, p. 3461-3475, 2021. DOI: 10.1007/s11581-021-04107-9

    Abstract: A complete non-isothermal model of a HT-PEMFC setup using a PBI/ H3PO4 membrane was developed, modeled, and solved using COMSOL Multiphysics. Polarization curves were simulated and compared to the corresponding experimental data. In this work, a serpentine flow field and an active area of 5 cm2 have been implemented in a computational fluid dynamics (CFD) application. The model predicts water vapor transport, mass concentration of H3PO4, temperature, and membrane current density distribution. In this model, the anode feed is pure hydrogen, and oxygen is introduced at the cathode side. The heat transfer model was coupled with the electrochemical and mass transport; a particular heating configuration is investigated for temperature distribution, emphasizing the membrane. The models showed consistency and were used to investigate the behavior of H3PO4 concentration and all transport characteristics. The concentration of phosphoric acid decreases with increasing temperature and relative humidity and the diffusive flux of water vapor increases with the decrease of the operating voltage. Two different configurations of inlet and outlet flow channels were analyzed and the results were compared.

    Palavras-Chave: fuel cells; phosphoric acid; fluid mechanics; efficiency; computer calculations; dynamics

  • IPEN-DOC 28364

    FONSECA, HUGO M.; SANTOS, CAMILA O.; CRUZ, LUIS P.A.; ARTHUR, VALTER ; FREITAS, BARBARA C.B.; SOUZA, ADRIANA R.M.; MARTINS, GLENDARA A.de S.. The effects of microwave application on the physicochemical properties of bacaba (Oenocarpus bacaba Mart.) oil. Acta Scientiarum Polonorum Technologia Alimentaria, v. 20, n. 2, p. 189-196, 2021. DOI: 10.17306/J.AFS.2021.0893

    Abstract: BACKGROUND Bacaba (Oenocarpus bacaba Mart.) has a high yield of oil, with the potential to produce biologically active natural products and can be considered a new "superfruit" with high value added. METHODS Acid value, peroxide value, refractive index, saponification value, p-anisidine value, relative density, iodine value, total oxidation value, specific extinction coefficients at 232 and 270 nm (K232 and K270), ΔK, and color were determined. RESULTS The most significant changes in the quality values, such as peroxide (26.25 mEq·kg-1), p-anisidine (11.41), acidity (14.66 mg KOH·g-1 oil), and total oxidation (63.92) were determined for 15 min of microwave heating. CONCLUSIONS The microwave heating promoted the acceleration of oxidative processes showing that, overall, much care should be taken when heating the bacaba oil by microwave to avoid oil degradation.

    Palavras-Chave: fruits; vegetable oils; microwave radiation; radiation effects; heating; tropical regions

  • IPEN-DOC 28363

    RODRIGUES, PRISCILA S. ; BURIMOVA, ANASTASIA ; SALES, TATIANE S.N. ; FILHO, ARNALDO A.M. ; OTUBO, LARISSA ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . The effect of Er doping on local structure of magnetite nanoparticles. Hyperfine Interactions, v. 242, n. 38, p. 1-6, 2021. DOI: 10.1007/s10751-021-01767-x

    Abstract: In this work Fe3O4:Er nanoparticles (NPs) with the characteristic size of ~ 11 nm were synthesized via classic co-precipitation method. Electron microscopy and X-ray diffraction were employed to probe the morphology and structure of the samples. Results revealed that samples synthesized in the Fd-3mZ structure with lattice constant close to that of pure magnetite. 111In probe generator was incorporated at synthesis in order to map the evolution of hyperfine magnetic field with temperature using time differential perturbed angular correlation (TDPAC) spectroscopy. The TDPAC results are discussed in terms of the effect of Er dopant on the magnetic properties and local structure of the NPs.

    Palavras-Chave: differential pac; coprecipitation; nanoparticles; magnetic properties; doped materials

  • IPEN-DOC 28362

    NUNES, PAULO S.G.; SILVA, GABRIEL da; NASCIMENTO, SOFIA ; MANTOANI, SUSIMAIRE P.; ANDRADE, PETERSON de; BERNARDES, EMERSON S. ; KAWANO, DANIEL F.; LEOPOLDINO, ANDREIA M.; CARVALHO, IVONE. Synthesis, biological evaluation and molecular docking studies of novel 1,2,3-triazole-quinazolines as antiproliferative agents displaying ERK inhibitory activity. Bioorganic Chemistry, v. 113, p. 1-12, 2021. DOI: 10.1016/j.bioorg.2021.104982

    Abstract: ERK1/2 inhibitors have attracted special attention concerning the ability of circumventing cases of innate or log-term acquired resistance to RAF and MEK kinase inhibitors. Based on the 4-aminoquinazoline pharmacophore of kinases, herein we describe the synthesis of 4-aminoquinazoline derivatives bearing a 1,2,3-triazole stable core to bridge different aromatic and heterocyclic rings using copper-catalysed azide-alkyne cycloaddition reaction (CuAAC) as a Click Chemistry strategy. The initial screening of twelve derivatives in tumoral cells (CAL-27, HN13, HGC-27, and BT-20) revealed that the most active in BT-20 cells (25a, IC50 24.6 μM and a SI of 3.25) contains a more polar side chain (sulfone). Furthermore, compound 25a promoted a significant release of lactate dehydrogenase (LDH), suggesting the induction of cell death by necrosis. In addition, this compound induced G0/G1 stalling in BT-20 cells, which was accompanied by a decrease in the S phase. Western blot analysis of the levels of p-STAT3, p-ERK, PARP, p53 and cleaved caspase-3 revealed p-ERK1/2 and p-STA3 were drastically decreased in BT-20 cells under 25a incubation, suggesting the involvement of these two kinases in the mechanisms underlying 25a-induced cell cycle arrest, besides loss of proliferation and viability of the breast cancer cell. Molecular docking simulations using the ERK-ulixertinib crystallographic complex showed compound 25a could potentially compete with ATP for binding to ERK in a slightly higher affinity than the reference ERK1/2 inhibitor. Further in silico analyses showed comparable toxicity and pharmacokinetic profiles for compound 25a in relation to ulixertinib.

    Palavras-Chave: phosphotransferases; chemistry; enzyme inhibitors; tumor cells; hexokinase

  • IPEN-DOC 28361

    BRAGUIN, L.N.M. ; SILVA, C.A.J. da ; BERBEL, L.O. ; VIVEIROS, B.V.G. de ; ROSSI, J.L. ; COSTA, I. ; SAIKI, M. . A study on corrosion resistance of ISO 5832-1 austenitic stainless steel used as orthopedic implant. International Journal of Advances In Medical Biotechnology, v. 3, n. 2, p. 23-28, 2020. DOI: 10.25061/ijamb.v3i2.83

    Abstract: The ISO 5832-1 austenitic stainless steel used as biomaterial is largely applied in the area of orthopedics, especially in the manufacture of implants, such as temporary or permanent replacement of bone structures. The objective of this study was to evaluate the localized corrosion resistance of the ISO 5832-1 stainless steel used in orthopedic implants by electrochemical tests in two different solutions. The results of this study are of great interest to evaluate the corrosion of metallic implants that can result in the release of corrosion products into bodily fluids causing possible adverse biological reactions. The determination of the chemical elements in the composition of the ISO 5832-1 stainless steel was performed by neutron activation analysis (NAA). The samples for electrochemical tests were grinded with silicon carbide paper up to #4000 finishing, followed by mechanical polishing with diamond paste. The open circuit potential measurements and anodic polarization curves were obtained in solution of 0.90 wt. % of NaCl and of simulated body fluid (SBF). The results indicated that the ISO 5832-1 stainless steel presented a high resistance to crevice corrosion in simulated body fluid solution but high susceptibility to this form of corrosion in the chloride solution.

    Palavras-Chave: austenitic steels; implants; metals; stainless steels; corrosion resistance

  • IPEN-DOC 28360

    SILVA, CAIO A.J. da ; BRAGUIN, LILIAN N.M. ; BERBEL, LARISSA O. ; VIVEIROS, BARBARA V.G. ; ROSSI, J.L. ; SAIKI, M. ; COSTA, I. . Study of ph effect on AZ31 magnesium alloy corrosion for using in temporary implants. International Journal of Advances In Medical Biotechnology, v. 3, n. 2, p. 15-22, 2020. DOI: 10.52466/ijamb.v3i2.72

    Abstract: Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone. However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.

    Palavras-Chave: magnesium alloys; implants; corrosion; neutron activation analysis; sodium chlorides; chemical analysis

  • IPEN-DOC 28359

    FRANCISCO, LEONARDO H.C. ; MOREIRA, RENAN P. ; FELINTO, MARIA C.F.C. ; TEIXEIRA, VERONICA C.; BRITO, HERMI F.; MALTA, OSCAR F.. SrAl2O4: Eu2+, Dy3+ persistent luminescent materials functionalized with the Eu3+(TTA)-complex by microwave-assisted method. Journal of Alloys and Compounds, v. 882, p. 1-12, 2021. DOI: 10.1016/j.jallcom.2021.160608

    Abstract: Recently, several classes of rare-earth-doped luminescent materials have been drawing attention due to structurally engineered energy converting systems, capable of tuning absorption and emission spectral ranges, outlining new materials and applications in photonics. In this scenario, this work presents the development of SrAl2O4:Eu2+,Dy3+ phosphors prepared by the Pechini method, which were further APTMS-functionalized (3-aminopropyltrimethoxysilane) by microwave-assisted synthesis, incorporating a Eu3+ β-diketonate complex embedded within a SiO2-R network to increase light absorption and promote energy transfer processes. Powder X-ray diffraction data revealed a stable characteristic monoclinic phase of the SrAl2O4 host matrix, which undergoes structural changes after functionalization. Particle morphology and elemental distribution were probed by scanning electron microscopy technique, exhibiting surface alteration effects. Photoluminescence spectra displayed a characteristic broad green emission band assigned to the 4f65d1(2D) → 4f7(8S7/2) interconfigurational transition of the Eu2+ ion. Functionalized materials presented absorption shifts coupled with an emission band intensification suggesting effective interactions between the β-diketonate complex, the SiO2-R network, and the inorganic host matrix. Increased absorption range and persistence decay time under near band gap excitation on modified materials were also observed.

    Palavras-Chave: rare earths; strontium; aluminates; ketones; luminescence

  • IPEN-DOC 28358

    BISPO, FABIO H.A.; MENEZES, MICHELE D. de; FONTANA, ADEMIR; SARKIS, JORGE E. de S. ; GONCALVES, CRISTIANO M.; CARVALHO, TEOTONIO S. de; CURI, NILTON; GUILHERME, LUIZ R.G.. Rare earth elements (REEs): geochemical patterns and contamination aspects in Brazilian benchmark soils. Environmental Pollution, v. 286, p. 1-12, 2021. DOI: 10.1016/j.envpol.2021.117972

    Abstract: Rare earth elements have been increasingly used in modern societies and soils are likely to be the final destination of several REE-containing (by)products. This study reports REE contents for topsoils (0–20 cm) of 175 locations in reference (n = 68) and cultivated (n = 107) areas in Brazil. Benchmark soil samples were selected accomplishing a variety of environmental conditions, aiming to: i) establishing natural background and anthropogenic concentrations for REE in soils; ii) assessing potential contamination of soils - via application of phosphate fertilizers - with REE; and, iii) predicting soil-REE contents using biomes, soil type, parent material, land use, sand content, and biomes-land use interaction as forecaster variables through generalized least squares multiple regression. Our hypotheses were that the variability of soil-REE contents is influenced by parent material, pedogenic processes, land use, and biomes, as well as that cultivated soils may have been potentially contaminated with REE via input of phosphate fertilizers. The semi-total concentrations of REE were assessed by inductively coupled plasma mass spectrometry (ICP-MS) succeeding a microwave-assisted aqua regia digestion. Analytical procedures followed a rigorous QA/QC protocol. Soil physicochemical composition and total oxides were also determined. Natural background and anthropogenic concentrations for REE were established statistically from the dataset by the median plus two median absolute deviations method. Contamination aspects were assessed by REE-normalized patterns, REE fractionation indices, and Ce and Eu anomalies ratios, as well as enrichment factors. The results indicate that differences in the amounts of REE in cultivated soils can be attributed to land use and agricultural sources (e.g., phosphate-fertilizer inputs), while those in reference soils can be attributed to parent materials, biomes, and pedogenic processes. The biomes, land use, and sand content helped to predict concentrations of light REE in Brazilian soils, with parent material being also of special relevance to predict heavy REE contents in particular.

    Palavras-Chave: rare earths; environment; geochemistry; tropical regions; soils; surface contamination; anthropocene

  • IPEN-DOC 28357

    SILVA, CAMILA R. ; SALVEGO, CAMILA de A. ; ROSTELATO, MARIA E. ; ZEITUNI, CARLOS A. ; RIBEIRO, MARTHA S. . Photobiomodulation therapy combined with radiotherapy in the treatment of triple-negative breast cancer-bearing mice. Journal of Photochemistry and Photobiology B: Biology, v. 220, p. 1-9, 2021. DOI: 10.1016/j.jphotobiol.2021.112215

    Abstract: This work investigated the effect of photobiomodulation therapy (PBM) combined with radiotherapy (RT) on triple-negative breast cancer (TNBC)-bearing mice. Female BALB/c mice received 4 T1 cells into a mammary fat pad. Local RT was performed with a total dose of 60 Gy divided into 4 consecutive sessions of 15 Gy. For PBM, a red laser was used in three different protocols: i-) single exposure delivering 150 J.cm−2 (24 h after the last RT session), and ii-) radiant exposure of 150 J.cm−2 or iii-) fractionated radiant exposure of 37.5 J.cm−2 (after each RT session). Tumor volume, complete blood cell count, clinical condition, metastasis, and survival of animals were monitored during 3 weeks post-RT. Our results demonstrated that regardless of the protocol, PBM arrested the tumor growth, improved the clinical condition, and prevented hemolytic anemia. Besides, although PBM groups have exhibited a high neutrophil:lymphocyte ratio (NLR), they decreased the number of lung metastases and enhanced mouse survival. Worthy of note, PBM should be used along with the RT sessions in higher radiant exposures, since PBM at 150 J.cm−2 per session significantly extended the survival rate. Together, these data suggest PBM could be a potential ally to RT to fight TNBC.

    Palavras-Chave: laser radiation; modulation; therapy; neoplasms; mammary glands; blood count; infrared radiation

  • IPEN-DOC 28356

    MIZUTANI, G. ; BUSTILLOS, O. . Pesticides analysis in beans by gas chromatography couplet with tandem mass spectrometry. Annals of Agricultural & Crop Sciences, v. 6, n. 4, p. 1-7, 2021. DOI: 10.26420/annagriccropsci.2021.1082

    Abstract: Beans are part of the basic diet alimentation for Brazilian population, as they gather proteins, carbohydrates, vitamins, mineral salts, fibers, amino acids and essential nutrients such as iron and calcium, being a complete food that can be compared with the amount of protein that the meat has. Considering the beans world production, in development countries represent almost 50%, being that Myanmar, India and Brazil the top three position. The use of pesticides is widely spread in these countries to reduce agricultural losses due to pests that interfere with grain production. Therefore the risk that could be generated from foods pesticides residues makes their analyses of quantification mandatory. The purpose of this work was to develop an analytical method to quantitatively characterize fungicides pesticides residues, flutriafol, procymidone and tebuconazole that were used to angular spot control, anthracnose, rust and alternaria spot, white mold fungi, present in beans, by means of gas chromatography coupled with a triple quadrupole mass spectrometer. Samples of beans, Phaseolus vulgaris L, types white, black, string and Vigna angularis, type adzuki, had been bought in grains store and supermarkets at metropolitan São Paulo city. The validation of analytical method was explored for sensitivity, selectivity, precision. The extraction procedure was performed in two different forms, QuEChERS, and solid-liquid extraction with low temperature. Through this methodology, reached below the maximum limit allowed by Brazilian law 0.5mgkg-1 for procymidone and 0.1mgkg-1 for flutriafol and tebuconazole. Several samples of four types of beans were tested and all of them had procymidone identified and 7% of samples higher than the law limit.

    Palavras-Chave: pesticides; agriculture; beans; gas chromatography; quantitative chemical analysis

  • IPEN-DOC 28355

    RIBEIRO, DANIEL V.; AMORIM JUNIOR, NILSON S.; ANDRADE NETO, JOSE S.; ALBUQUERQUE, DIANA D.M.; MAZZILLI, BARBARA P. . Performance and radiological implications of using residue from TiO2 production as a component of coating mortars. Construction and Building Materials, v. 306, p. 1-12, 2021. DOI: 10.1016/j.conbuildmat.2021.124885

    Abstract: The objective of this study was to investigate the effect of the addition of residue from the production of TiO2, namely, unreacted ore waste (UOW), on the properties of coating mortars as well as evaluate its radiological impact. The properties of the mixed cement lime mortars were evaluated after the addition of 5%, 10%, and 15% of UOW, in relation to the cement mass, with respect to the reference mortar. The coating mortars were evaluated for rheology, dynamic elastic modulus, and mechanical strength. Tests in the applied state were performed using panels. From the point of view of radiological protection, the concentration of natural radionuclides in the residue, components of the mortar, and ready mortar were determined. In addition, the concentration of radon in the air and the exposure of dwellers living in a standard room coated with mortar were evaluated. The results obtained indicated that UOW did not compromise the use of coating mortars, presenting no significant effect on the properties of fresh, hardened, and applied states. Although the UOW presented high concentration of radionuclides, mortars with 5%, 10%, and 15% of UOW led to a gamma exposition and indoor radon concentration (average values of 0.20 mSv.a-1 and 71 Bq.m−3, respectively) below the recommended limits (1 mSv.a-1 and 100 Bq.m−3). Thus, it is concluded that UOW can be incorporated into coating mortars without presenting risks to the health of users due to radiation exposure.

    Palavras-Chave: building materials; mortars; ore concentrates; titanium oxides

  • IPEN-DOC 28354

    CABRAL, FERNANDA V. ; LIAN, CHENG; PERSHEYEV, SAYDULLA; SMITH, TERRY K.; RIBEIRO, MARTHA S. ; SAMUEL, IFOR D.W.. Organic light-emitting diodes as an innovative approach for treating cutaneous leishmaniasis. Advanced Materials Technologies, v. 6, n. 11, p. 1-9, 2021. DOI: 10.1002/admt.202100395

    Abstract: Antimicrobial photodynamic therapy (APDT) has been studied as a noninvasive therapy for treating cutaneous leishmaniasis to overcome challenges with current treatment, such as toxicity, resistance, and need for in-patient hospital treatment. Organic light-emitting diodes (OLEDs) have emerged as an attractive technology that can provide wearable light-emitting materials that are conformable to human skin. This makes OLEDs ideal candidates for APDT by light-bandages for ambulatory care. In this work, suitable OLEDs are successfully developed to match the absorbance of three photosensitizers: methylene blue, new methylene blue, and 1,9-dimethyl-methylene blue to inactivate two Leishmania species in vitro: Leishmania major and Leishmania amazonensis. Parasites are treated either by LED (20 mW cm−2) or OLED (6.5 mW cm−2) at increasing photosensitizer concentrations at a radiant exposure of 50 J cm−2. 1,9-Dimethyl-methylene blue is the most potent photosensitizer, killing both strains at nanomolar concentrations. The effect of different intensities from the OLEDs (0.7, 1.5, and 6.5 mW cm−2) are also explored and it is shown that effective killing of Leishmania occurs even at a very low intensity. These findings demonstrate the great potential of OLEDs as a new approach for ambulatory treatment of cutaneous leishmaniasis by APDT.

    Palavras-Chave: antibiotics; antimicrobial agents; light emitting diodes; organic compounds; parasites; photosensitivity

  • IPEN-DOC 28353

    GONCALVES, SILAS A.; CANAZZA, SAMUEL A.; COSTA, FABIO E. da ; HAMADA, MARGARIDA M. . Obtenção e análise de espectros de energia para detectores de radiação com osciloscópio digital e software tipo planilha eletrônica / Obtaining and analysis of the energy spectra for radiation detectors with digital oscilloscope and worksheet software. Brazilian Journal of Development, v. 7, n. 9, p. 91027-91040, 2021. DOI: 10.34117/bjdv7n9-319

    Abstract: Detectores de radiação que produzem um pulso, cuja amplitude é proporcional a energia da radiação incidente, permitem com auxílio de uma eletrônica apropriada e de um analisador multicanal, a obtenção do espectro de energia da radiação incidente sobre o detector. Devido ao analisador multicanal nem sempre estar disponível em laboratórios, este trabalho propõe uma alternativa de medida do espectro utilizando-se dos recursos disponíveis nos osciloscópios digitais de efetuar a medida da amplitude dos pulsos e enviar a um computador tipo PC. No computador, uma planilha eletrônica adequadamente configurada pode então trabalhar os dados coletados no osciloscópio e obter o espectro de energia. Adicionalmente, um segundo recurso permite a seleção temporal da largura do pulso que minimiza leituras incorretas da amplitude na eventualidade de ocorrer empilhamento de pulsos. Para os experimentos foram utilizados um osciloscópio Tektronix TDS 30302B e a planilha eletrônica Excel®. Os espectros foram comparados com os obtidos com um analisador multicanal e se mostraram iguais ou melhores, mas que tiveram como limitação a baixa taxa de aquisição do osciloscópio que foi da ordem de apenas 2 pulsos/seg, portanto milhares de vezes menor que de um analisador multicanal.

    Palavras-Chave: energy spectra; oscillographs; digital systems; multi-channel analyzers; radiation detectors

  • IPEN-DOC 28352

    VERDE, MARIA E.Q.L.; FERREIRA-JUNIOR, ANTONIO E.C.; BARROS-SILVA, PAULO G. de; MIGUEL, EMILIO de C.; MATHOR, MONICA B. ; LIMA-JUNIOR, EDMAR M.; MORAES-FILHO, MANOEL O. de; ALVES, ANA P.N.N.. Nile tilapia skin (Oreochromis niloticus) for burn treatment: ultrastructural analysis and quantitative assessment of collagen. Acta Histochemica, v. 123, n. 6, p. 1-8, 2021. DOI: 10.1016/j.acthis.2021.151762

    Abstract: Nile tilapia (Oreochromis niloticus) skin is a well-known biomaterial used as an occlusive dressing for burn treatment. It is also an inexpensive and important source of collagen. This study aims to describe the ultrastructural aspects of Nile tilapia skin, assess its collagen amount and organization, and compare quantitative methods of histochemical and immunohistochemical analysis (in all sterilization steps for use in burn dressings). One sample (0.5 x 0.5 cm) of ten different fish skins was divided in four groups: in natura skin (IN), chemical sterilization (CH), additional irradiation (30 kGy) (IR), and skins used in burn treatment (BT) to compare histochemical and immunohistochemical findings of collagen amount and describe ultrastructural aspects through scanning electron microscopy. The amount of type I collagen decreased during sterilization and clinical use owing to gradual reduction of immunostaining (anti-collagen-I) and decreasing fiber thickness of the collagen, when compared to type III (Picrosirius-red-polarized light). The collagen fibers were rearranged at each sterilization step, with a low collagen percentage and large structural disorganization in BT. The amount of type-I collagen was further reduced after BT (p < 0.05). Both the methods did not exhibit a quantified value difference (p = 0.247), and a positive correlation (r = 0.927; 95 % CI = 0.720–0.983) was observed between them, with concordance for collagen quantification in similar samples, presenting a low systematic error rate (Dalberg coefficient: 6.70). A significant amount of type-I collagen is still observed despite sterilization, although clinical application further reduces type I collagen. Its quantification can be performed both by immunohistochemistry and/or Picrosirius Red reliably.

    Palavras-Chave: burns; therapy; animal tissues; collagen; fishes; biological materials

  • IPEN-DOC 28351

    SILVA, JOSE T. ; SOUZA, CARLA D. de ; ANGELOCCI, LUCAS V. ; ROSERO, WILMMER A.A. ; NOGUEIRA, BEATRIZ R. ; CORREIA, RUANYTO W. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . New model for an epoxy-based brachytherapy source to be used in spinal cancer treatment. Applied Radiation and Isotopes, v. 178, p. 1-7, 2021. DOI: 10.1016/j.apradiso.2021.109952

    Abstract: The present work described the cold fabrication of a P-32 radioactive source to be used in CNS cancer using epoxy resin. The epoxy plaque fabricated with Teflon mold presented better agreement. MCNP simulation evaluated the radiation dose. Special attention was given to factors that can impact dose distribution. Average dose was 16.44 ± 2.89% cGy/s. Differences of less than 0.01 cm in thickness within the plaque lead to differences of up to 12% in the dose rate.

    Palavras-Chave: epoxides; brachytherapy; neoplasms; central nervous system; monte carlo method; radiation doses

  • IPEN-DOC 28350

    SILVA, B.C.; CURY, L.A.; LEAL, A.S.; MENEZES, M.A.B.C.; NAGORNY, S.; NISI, St.; SAIKI, M. ; JACIMOVIC, R.; KRAMBROCK, K.. Neutron-induced point defects and luminescence properties of enriched Zn82Se crystals. Journal of Applied Physics, v. 130, n. 5, p. 1-11, 2021. DOI: 10.1063/5.0052503

    Abstract: Enriched Zn82Se is a very promising material for the detection of the neutrionoless double beta decay. The 82Se isotope acts as the source of the decay, and ZnSe detects the scintillation and bolometric events. Due to the high cost in the preparation of the Zn82Se material, the optimization of its properties, especially those related to the scintillation process, is mandatory. It is well known that excellent scintillation efficiency in ZnSe is obtained when the material presents close donor–acceptor pairs, as, for example, the A-centers. In this work, neutron irradiation was used to study formation of point defects in enriched and non-enriched ZnSe samples. Applying instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectroscopy, the enrichment of Zn82Se samples was determined to ∼95%, in addition, trace impurities such as Cu, I, and Na were quantified by INAA at the μg/g level. Based on electron paramagnetic resonance (EPR) and photo-EPR measurements, we show that irradiation with fast neutrons induced point defects such as the isolated zinc vacancy (VZn) and a new low-symmetric donor center called NC1, which we tentatively assign to Zn di-interstitials. Low-temperature photoluminescence measurements of the neutron-irradiated Zn82Se revealed three broad PL bands centered in the visible spectral range. Based on the INAA analysis shown in this work, we attribute the previously unidentified 540 nm PL band in the Zn82Se sample to recombination between shallow donors and deep copper acceptors. The formation of point defects by neutron irradiation and their stability are discussed.

    Palavras-Chave: neutron sources; irradiation; zinc selenides; zinc 82; luminescence

  • IPEN-DOC 28349

    HARDER, MARCIA N.C. ; FORMAGGIO, IAN H.; HARDER, LARISSA N.C. ; BOVI, DEBORA C.M. de L.; ARTHUR, PAULA B. ; ARTHUR, VALTER . Natural coloring red beetroot under effects of gamma radiation. Horticulture International Journal, v. 5, n. 3, p. 129‒132, 2021. DOI: 10.15406/hij.2021.05.00218

    Abstract: As color is an important attribute related to the visual appeal and quality of food products, the reduction of pigment losses during food processing is a basic concern fr the industry. Based on this, the objective of this work was to evaluate the resistance of betalain from beet against the use of gamma radiation. Analyzes were carried out on pigments belonging to the betalain class on beets exposed to different doses of gamma radiation (Co60) using doses of 5, 10 and 15 kGy on beets, in addition to anon-irradiated sample for control. Color parameters were evaluated using the CIE L, a*, b * methodology, as well as the quantification of betalain in the samples. By of results the color parameters were affected in until 50% in relation the control. And the quantity betalain activity in the sample irradiated with doses of gamma radiation was more less 65% in relation the control. Therefore, it can be concluded that there is a potential resistance of the betalain pigment in the face of high doses of radiation, which returns interest to red beetroot dyes since most pigments are fragile to thermal treatments or with ionizing radiation.

    Palavras-Chave: beets; gamma radiation; color; food processing; irradiation

  • IPEN-DOC 28348

    GARCIA, VANESSA S.G. ; TALLARICO, LENITA de F.; ROSA, JORGE M. ; SUZUKI, CELSO F.; ROUBICEK, DEBORAH A.; NAKANO, ELIANA; BORRELY, SUELI I. . Multiple adverse effects of textile effluents and reactive Red 239 dye to aquatic organisms. Environmental Science and Pollution Research, v. 28, n. 44, p. 63202-63214, 2021. DOI: 10.1007/s11356-021-15115-7

    Abstract: Textile dyeing consumes high volumes of water, generating proportional number of colored effluents which contain several hazardous chemical. These contaminants can implicate in significant changes in aquatic environmental, including several adverse effects to organisms in different trophic levels. The present study was developed to assess the ecotoxicological effects of textile effluent samples and reactive Red 239 dye (used in cotton dyeing) to aquatic organisms Vibrio fischeri bacteria, Daphnia similis crustacean, and Biomphalaria glabrata snail (adults and embryos). Chronic assays with lethal and sublethal effects for Daphnia similis were included and performed only for textile effluents samples. The mutagenicity was also evaluated with Salmonella/microsome assay (TA98, TA100, and YG1041 strains). V. fischeri bacteria was the most sensitive to reactive Red 239 dye (EC50 = 10.14 mg L−1) followed by mollusk embryos at all stages (EC50 = 116.41 to 124.14 mg L−1), D. similis (EC50= 389.42 mg L−1), and less sensitive to adult snails (LC50= 517.19 mg L−1). The textile effluent was toxic for all exposed organisms [E(L)C50 < 15%] and B. glabrata embryos showed different responses in the early stages of blastulae and gastrulae (EC50 = 7.60 and 7.08%) compared to advanced development stages trochophore and veliger (EC50 = 21.56 and 29.32%). Developmental and sublethal effects in B. glabrata embryos and D. similis were evidenced. In the chronic assay with effluent, the EC10/NOEC = 3% was obtained. Mutagenic effects were not detected for dye aqueous solutions neither for effluents samples. These data confirmed the importance of evaluating the effects in aquatic organisms from different trophic levels and reinforce the need for environmental aquatic protection.

    Palavras-Chave: textile industry; liquid wastes; dyes; toxicity; color; daphnia; waste water

  • IPEN-DOC 28347

    MONTALVAN-OLIVARES, D.M.; SANTANA, C.S.; VELASCO, F.G.; LUZARDO, F.H.M.; ANDRADE, S.F.R.; TICIANELLI, R.B. ; ARMELIN, M.J.A. ; GENEZINI, F.A. . Multi-element contamination in soils from major mining areas in Northeastern of Brazil. Environmental Geochemistry and Health, v. 43, n. 11, p. 4553-4576, 2021. DOI: 10.1007/s10653-021-00934-x

    Abstract: Mining has become one of the main factors in the global biogeochemical cycle of potentially toxic elements. Therefore, it is considered one of the anthropogenic activities with the greatest negative impact on the environment. These impacts are maximized in semiarid regions, where mining activities can lead to soil degradation and decrease in land productivity. This study aimed to assess the level of contamination in natural, urban, and agricultural soils of three important mining areas, where approximately 80,000 people live, and pollution levels have never been determined before. For this purpose, soil samples were collected around iron, uranium, and vanadium mines, as well as in the main human settlements of the region. The concentrations of 34 elements were determined by instrumental neutron analysis activation (INAA) and inductively coupled plasma optical emission spectrometry (ICP OES) techniques. Pollution indices (CF, EF, mCd, PLI, and REEP) revealed that there is a moderate to heavy level of pollution for 89% of the analyzed elements. Additionally, an extreme contamination level was observed in 78% of the samples, for at least one element. Statistical analyses were performed to identify patterns in the distribution and common sources of pollution. The results suggest that the concentrations for Al, Ba, Hf, Na, Pb, Rb, REE, Ta, Th, U, Zn, and Zr are associated with geogenic causes. However, the influence of anthropogenic sources such as agriculture and mining on the accumulation of these elements in soils should not be disregarded. In contrast, the contents of As, Br, Cd, Co, Cr, Cs, Cu, Fe, K, Mn, Ni, Sc, Ti, and V reflect the direct impact of anthropogenic sources.

    Palavras-Chave: soils; pollution; trace amounts; mining; neutron activation analysis; environmental impacts; emission spectroscopy; plasma

  • IPEN-DOC 28346

    JANUARIO, ELIANE R. ; SILVAINO, PATRICIA F. ; MACHADO, ARTHUR P. ; VAZ, JORGE M. ; SPINACE, ESTEVAM V. . Methane Conversion Under Mild Conditions Using Semiconductors and Metal-Semiconductors as Heterogeneous Photocatalysts: State of the Art and Challenges. Frontiers in Chemistry, v. 9, p. 1-11, 2021. DOI: 10.3389/fchem.2021.685073

    Abstract: The processes currently used in the chemical industry for methane conversion into fuels and chemicals operate under extreme conditions like high temperatures and pressures. In this sense, the search for methane conversion under mild conditions remains a great challenge. This review aims to summarize the use semiconductors and metal-semiconductors as heterogeneous photocatalysts for methane conversion under mild conditions into valuable products. First, a brief presentation of photochemical conversion of methane is provided and then the focus of this review on the use of heterogeneous photocatalysts for methane conversion are described. Finally, the main challenges and opportunities are discussed.

    Palavras-Chave: semiconductor materials; photocatalysis; heterogeneous catalysis; methane

  • IPEN-DOC 28345

    HATTORI, C.S. ; ALMEIDA, G.F.C. ; GONCALVES, R.L.P.; SANTOS, R.G.; SOUZA, R.C.; SILVA JUNIOR, W.C. da; CUNALI JUNIOR, J.R.C.; COUTO, A.A. . Microstructure and fatigue properties of extruded aluminum alloys 7046 and 7108 for automotive applications. Journal of Materials Research and Technology, v. 14, p. 2970-2981, 2021. DOI: 10.1016/j.jmrt.2021.08.085

    Abstract: This work aimed to obtain by extrusion two aluminum alloys, 7108 and 7046. The microstructural characterized at each stage of the manufacturing process and the mechanical fatigue behavior of the extruded profile were evaluated. The aluminum alloys in the as-casted condition exhibited an interdendritic microsegregation inside the grains, with intermetallic phases precipitated on the grain boundaries. In the homogenization of the billets of the AA7108 and AA7046, the precipitated phases dissolved. The AA 7046, in the as-casted condition, displayed shrinkage microvoids throughout the length of the billet and a microstructure of heterogeneous grains, with the presence of a remelted layer at a maximum depth of 10 mm. The AA7046 displayed better tensile and fatigue properties than the AA7108. A higher surface roughness facilitated the initiation and propagation of cracks during the fatigue cycles. This effect was more pronounced with low levels of maximum stress and high number of cycles to failure. Deep secondary cracks perpendicular to the growth direction of the main crack were visible on all fracture surfaces. In the medium and high cycle fatigue tests of the AA7108 and AA7046, the cracks advanced in a perpendicular direction to the elongated grains resulting from the extrusion process. The fracture surfaces of the tested samples with a high number of cycles exhibited a region with a smaller crack propagation area and a larger region of rupture due to mechanical overload. The region of crack propagation is characterized by plastic deformation and the presence of striations perpendicular to the growth direction.

    Palavras-Chave: aluminium alloys; microstructure; extrusion; fracture mechanics; fatigue; automotive industry

  • IPEN-DOC 28344

    ALVES, ANDRESSA A.; QUEIROZ, ALFREDO A.A.E. de; SOARES, CARLOS R.J. ; QUEIROZ, ALVARO A.A. de . Microfluidic caging lipase in hyperbranched polyglycerol microcapsules for extracorporeal treatment of enzyme pancreatic insufficiency. Journal of Biomaterials Science, Polymer Edition, v. 32, n. 18, p. 2349-2368, 2021. DOI: 10.1080/09205063.2021.1971820

    Abstract: Lipase cartridges are currently the mainstay of treatment to improve fat absorption related to pancreatic insufficiency (PI) in patients receiving enteral nutrition feedings. Enzyme immobilization is an essential prerequisite for designing lipase cartridges systems for efficient enzymatic fat hydrolysis. A microfluidic approach has been adopted to produce lipase (LIP) caged in hyperbranched polyglycerol microcapsules (HPGly). The resulting HPGly-LIP microcapsules are spherical and had an average diameter of 29 µm with monomodal size distribution. The optimum conditions determined by artificial neural networks were HPGly concentration of 10 wt.%, LIP loading of 20% (wt) and total flow rate in microfluidic cell of 1.0 mL/h. Under these conditions, the maximum capacity of the LIP that can be microencapsulated is around 85% with respect to the HPGly concentration of 10 wt.% and total flow rate in microfluidic cell of 1.0 mL/h. This resultant HPGly-LIP exhibited Michaelis–Menten coefficients of 1.138,14 mM (Km) and 0.49 U/mg (Vmax) showing higher activity compared to free LIP. Finally, the robust HPGly-LIP microcapsules showed excellent recyclability. The in vitro Analysis of the HPGly-LIP cytotoxicity showed that microcapsules had no cytotoxic effect to L929 fibroblasts cells and behaved very similar to the negative control. These features will be useful for the facile construction of biocatalytic systems with high efficiency, excellent recyclability and adequate biocompatibility for treatment of patients with PI receiving enteral nutrition feedings.

    Palavras-Chave: pancreas; inflammation; lipases; glycerol; toxicity

  • IPEN-DOC 28343

    AHMED, YASSMIN S.; DePAIVA, JOSE M.; AMORIM, FRED L.; TORRES, RICARDO D.; ROSSI, WAGNER de ; VELDHUIS, STEPHEN C.. Laser surface texturing and characterization of austenitic stainless steel for the improvement of its surface properties. The International Journal of Advanced Manufacturing Technology, v. 115, n. 5-6, p. 1795-1808, 2021. DOI: 10.1007/s00170-021-07284-z

    Abstract: Laser surface texturing (LST) is widely explored for modifying the surface topography of various materials. In this study, a detailed investigation of laser textured surfaces produced on austenitic stainless steel (AISI 304) was carried out. Three different textures (square, parallel, perpendicular) were produced by a Ti sapphire laser. The processed surfaces were characterized by surface morphology, phase structure, microhardness, surface roughness, and wettability. A ball-on-disk tribometer was used to study the tribological performance of both untextured and textured samples. The experimental observations demonstrate that LST improves both surface wettability and surface roughness. Average surface roughness (Ra) was increased by 350% and the contact angle was reduced from 43° to 22°. The textured surfaces show a lower coefficient of friction and better wear resistance than the untextured surface. Out of the investigated patterns, the square textures exhibited a maximum reduction of 68% in the friction coefficient and a 50% lower wear rate.

    Palavras-Chave: austenitic steels; stainless steels; lasers; surface properties; texture

  • IPEN-DOC 28342

    FORTES, GUSTAVO M.; SILVA, ANDRE L. da; CALIMAN, LORENA B.; FONSECA, FABIO C. ; GOUVEA, DOUGLAS. Interfacial segregation in Cl−-doped nano-ZnO polycrystalline semiconductors and its effect on electrical properties. Ceramics International, v. 47, n. 17, p. 24860-24867, 2021. DOI: 10.1016/j.ceramint.2021.05.212

    Abstract: In this study, interfacial segregation in Cl−-doped ZnO (0.0, 1.0, 3.0, 4.0, and 6.0 mol%) was explored as a strategy to compensate the space charge layer to decrease the electric potential barrier height at the grain boundaries and increase the overall electrical conductivity of the system. The focus of this work was to evaluate the dopant segregation and provide the first insights into the influence of interfacial segregation on the electrical properties. By using a systematic lixiviation method, we demonstrated that in addition to the bulk solubility, the Cl− anions segregated at both the surface and grain boundaries. Impedance spectroscopy measurements showed a four orders of magnitude reduction in the total electrical resistivity in the Cl−-doped ZnO samples compared to that of undoped ZnO. The calculated value of the electric potential barrier height decreased, as well as the activation energy for conduction, which decreased from 853 meV for undoped ZnO to 168 meV for 1.2 mol% Cl−-doped ZnO.

    Palavras-Chave: doped materials; segregation; zinc oxides; electrical properties; semiconductor materials; space charge

  • IPEN-DOC 28341

    FERREIRA, L.A.S. ; MUCCILLO, E.N.S. . Influence of the sintering method on densification, microstructure and electrical conductivity of 12Ce-TZP. Advances in Applied Ceramics, v. 120, n. 4, p. 202–208, 2021. DOI: 10.1080/17436753.2021.1919362

    Abstract: Zirconia containing 12 mol-% cerium oxide ceramics were prepared by solid state reaction utilising the conventional, fast firing and two-step sintering methods. The sintering temperature and time were varied aiming to determine ideal sintering profile for these methods. The monoclinic and tetragonal phase contents, microstructure and electrical conductivity of dense specimens were investigated. The linear shrinkage was found negligible up to 1100°C and the maximum rate of shrinkage was achieved at 1150°C. Densification increased up to 2 h for conventional sintered specimens. Stabilisation of tetragonal phase in non-isothermally sintered specimens occurred at a high temperature (1500°C). Specimens sintered by the two-step method attained high density along with small grain sizes. Optimised sintering profiles were determined for all the sintering methods used.

    Palavras-Chave: microstructure; electric conductivity; sintering; polycrystals; tetragonal lattices

  • IPEN-DOC 28340

    COUTO, CAMILA P. ; REVILLA, REYNIER I.; POLITANO, RODOLFO ; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; GRAEVE, IRES de; ROSSI, JESUALDO L. ; TERRYN, HERMAN. Influence of austenitisation temperatures during hot stamping on the local electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si. Corrosion Science, v. 190, p. 1-12, 2021. DOI: 10.1016/j.corsci.2021.109673

    Abstract: Scanning Kelvin probe force microscopy was used to evaluate the effect of austenitisation temperatures during hot stamping on the local electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si. A variation in the austenitisation temperature around 50 °C substantially altered the coating morphology as well as the local electrochemical behaviour of the system (coating/steel). Both coating layer and steel substrate became nobler as the austenitisation temperature increased. The former was due to the overall iron enrichment while the latter was related to the microstructural transformation during quenching. Therefore, the driving force for cathodic protection decreased as the austenitisation temperature increased.

    Palavras-Chave: atomic force microscopy; probes; austenite; electrochemistry; temperature dependence

  • IPEN-DOC 28339

    MUNHOZ, PEDRO M. ; NASCIMENTO, FERNANDO C. ; SILVA, LEONARDO G. de A. e ; HARADA, JULIO ; CALVO, WILSON A.P. . Influence of electron beam irradiation on the mechanical properties of pbat/pla polymeric blend / Influência da irradiação por feixe de electrões nas propriedades mecânicas da mistura polimérica pbat/pla. Brazilian Journal of Development, v. 7, n. 8, p. 79528-79537, 2021. DOI: 10.34117/bjdv7n8-252

    Abstract: The aim of this research was to evaluate the changes in the mechanical properties of poly(butylene adipate co-terephthalate)/poly(lactic acid) (PBAT/PLA) polymeric blend after the radiation process at different radiation doses. The irradiation was performed in an electron beam accelerator, with 1.5 MeV of energy and 25 mA electric current. The samples were irradiated with doses of 5, 10, 15, 25, 50, 65 and 80 kGy. Both irradiated and non-irradiated samples were characterized by Izod pendulum impact resistance and tensile strength at rupture. The results showed an increase of 44% in relation to Izod impact resistance at a dose of 65 kGy. However, the module of elasticity decreased 56% and tensile strength at rupture decreased 55% at the same radiation dose. In relation to elongation, significant alterations caused by electron beam irradiation was not observed. Therefore, it can be concluded that irradiated blends could be used to make environmentally friendly products, which could absorb impact energy.

    Palavras-Chave: electron beams; irradiation; butenes; copolymers; biodegradation

  • IPEN-DOC 28338

    AFFONSO, REGINA ; SUZUKI, MIRIAM F. ; MAGALHAES, GERALDO S.; BARTOLINI, PAOLO . Influence of the expression vector and its elements on recombinant human prolactin synthesis in Escherichia coli; co-directional orientation of replication and transcription is highly critical. Journal of Microbiological Methods, v. 191, p. 1-8, 2021. DOI: 10.1016/j.mimet.2021.106340

    Abstract: The aim of the present work was to define a bacterial expression system that is particularly efficient for the synthesis of recombinant human prolactin (hPRL). In previous work, based on experiments that were basically carried out in parallel with the present ones, the synthesis of rec-hPRL by the p1813-hPRL vector in E. coli HB2151 was >500 mg/L, while it was much lower here (2.5–4-fold), in the RB791 and RRI strains. The highest positive influence on rec-hPRL synthesis was due to the transcription-replication co-orientation of hPRL cDNA and the ori/antibiotic resistance gene, responsible for up to a ~ 5–6-fold higher expression yield. In conclusion, this work confirmed that each bacterial strain of E. coli has a genetic background that can allow a different level of heterologous protein synthesis. The individual study of each element indicated that its action critically depends on the reading orientation in which it is located inside the vector: co-directional orientation of replication and transcription, in fact, greatly increased the level of rec-hPRL expression

    Palavras-Chave: lth; escherichia coli; collisions; plasmids; dna

  • IPEN-DOC 28337

    ARAUJO, M.S. ; SILVA, A.C. ; CABAL, B.; BARTOLOME, J.F.; MELLO-CASTANHO, S. . In vitro bioactivity and antibacterial capacity of 45S5 Bioglass®-based compositions containing alumina and strontium. Journal of Materials Research and Technology, v. 13, p. 154-161, 2021. DOI: 10.1016/j.jmrt.2021.04.053

    Abstract: A modified 45S5 Bioglass® containing 2 mol% alumina and 2 mol% strontium oxide was prepared. In vitro bioactivity in powder and monolithic samples was conducted. Fourier transform infrared analysis and pH change in simulated body fluid were investigated for powder samples after 480 min of immersion. Additionally, X-ray diffraction and scanning electron microscopy after 7 and 14 days of immersion in simulated body fluid were investigated for monolithic samples. The formation of phosphate and carbonate phase precursors of hydroxycarbonate apatite was observed after 480 min for powder samples, and the hydroxycarbonate apatite pattern and morphology were confirmed after 7 days of immersion for monolithic samples. It seems that changes in composition did not affect reactivity but caused a decrease in the maxima of pH. Cytotoxicity and cell viability obtained by using the NCTC clone 929 cell line did not show any significant loss of cell viability or cytotoxicity. Moreover, after overnight incubation, the samples demonstrated safe disinfection for Escherichia coli. For these reasons, the use of these new bioactive glasses can be considered a promising alternative for the reconstruction of bone defects and even for the treatment and suppression of bone infections.

    Palavras-Chave: antibiotics; aluminium oxides; strontium; toxicity; apatites; biological materials

  • IPEN-DOC 28336

    BUSTILLOS, OSCAR V. . O espectro de massas na espectrometria de massas. Revista Analytica, n. 113, p. 18-21,

    Palavras-Chave: mass spectroscopy; mass spectra; nuclear energy; nuclear physics

  • IPEN-DOC 28335

    BUSTILLOS, OSCAR V. . A resolução de massas na espectrometria de massas. Revista Analytica, n. 112, p. 17-18, 2021.

    Palavras-Chave: mass spectroscopy; magnetic fields; mass resolution; charged particles; ions

  • IPEN-DOC 28334

    BUSTILLOS, OSCAR V. . A exatidão de massas na espectrometria de massas. Revista Analytica, n. 114, p. 24-27, 2021.

    Palavras-Chave: mass spectroscopy; electrons; ionization; mass spectra

  • IPEN-DOC 28333

    ALMEIDA, J.S. ; VILLANI, D. ; POTIENS, M.P. A. ; WILLEGAIGON, J.. Dosimetric characterization of 3D printed for 137Cs gamma rays. Journal of Physics: Conference Series, v. 1826, n. 1, p. 1-6, 2021. DOI: 10.1088/1742-6596/1826/1/012042

    Abstract: The aim this paper is characterize materials for 3D printed with different infill percentages for 137Cs gamma rays. The RAISE 3D PRO2 printer was used to print PLA and ABS plates. Using a 137Cs source, the attenuation coefficient was obtained by the transmission method and results compared with PMMA. The readings were performed by a Radcal ionization chamber, model 10X6-6. The results of attenuation coefficients show that the PLA filament demonstrated a equivalent behavior to PMMA. The PLA plates exhibits an increase in radiation transmission when reduces the infilling, and ABS printing achieved same results for all infills.

    Palavras-Chave: 3d printing; computer-aided fabrication; gamma radiation; cesium 137; phantoms

  • IPEN-DOC 28332

    MASTRO, NELIDA L. del . Evolution of the interest on edible insects. American Journal of Biological and Environmental Statistics, v. 7, n. 2, p. 52-56, 2021. DOI: 10.11648/j.ajbes.20210702.13

    Abstract: Insects are being used as foods in both ancient and present days in different societies. A FAO report of 2013 reckoned that insect, farming in a that large-scale, would be the most effective way to addressed global food insecurity. At present nevertheless, there are poor knowledge on sustainably of farm insects and about species that would be best suited commercially. In the present work a tentative was made to describe the state of the art up to today on the subject of edible insects with emphasis on the important facts about them. In particular, special attention was given to Tenebrio molitor and Hermetia illucens, considered among the most promising insect larvae with extraordinary potential to be a food source alternative. The role that they can play when looking for more environmentally friendly alternatives for proteins and fats and the role of edible insects in the preservation of the environment were highlighted. A survey on the Web of Science data base was made in order to establish the evolution on the number of published articles about edible insects and in particular the two mentioned edible insects with time. it is worth mentioning that until the 1980 decade, the number of published articles on edible insects was very poor. In the mentioned data base, it was found that the first article on that subject was published on 1973. The amazing and increasing interest on experimental studies using edible insects in the last three decades correlate to the search for alternative sources of quality proteins and other important nutrients found in edible insects, besides the classical protein sources such as meat or to a less extent, plant proteins.

    Palavras-Chave: insects; food processing; nutrients; sustainability; proteins

  • IPEN-DOC 28331

    ARTHUR, PAULA B. ; LEANDRO, RODRIGO S.R. ; HARDER, LARISSA N.C. ; HARDER, MARCIA N.C. ; ARTHUR, VALTER . Effects of gamma radiation in okra’s conservation. Horticulture International Journal, v. 5, n. 3, p. 134-137, 2021. DOI: 10.15406/hij.2021.05.00219

    Abstract: Okra is a very important vegetable in simple world cuisine. The aim of this work was to evaluate the effects of gamma radiation of Cobalt-60 in the conservation of okra (Abelmoschus esculentus). After 1 day of okras’s harvest, they were selected based in the size, presence of mechanical and phytophatologycal damages, and put in polystyrene trays and covered with thin polyethylene film. Then they were irradiated with doses of: 0 (control); 75; 100; 125; 150 and 200 Gy, at a dose rate of 0.259 kGy/h. The experiment was carried out in chamber regulated at 10o C of temperature and 80% of relative humidity. All analyses physical and chemical of the samples were carried out after 7 and 15 days of the storage. The results did not show any significative difference between the control and irradiated samples, except the viscosity that decreased with the increase of the dose of radiation. The dose of 75 Gy can be indicated to the conservation of okras because it was the one that showed best result in the coloration of okras.

    Palavras-Chave: vegetables; gamma radiation; food processing; ionizing radiations; cobalt 60; chemical analysis

  • IPEN-DOC 28330

    PORFIRIO, T.C ; MUCCILLO, E.N.S. ; MUCCILLO, R. . Electric field-assisted synthesis/sintering cerium oxide: 5 wt.% gadolinium oxide. Journal of the European Ceramic Society, v. 41, n. 14, p. 7105-7110, 2021. DOI: 10.1016/j.jeurceramsoc.2021.07.027

    Abstract: Gadolinium oxide ceramic powders were mixed to cerium oxide ceramic powders, pressed to pellets, and sintered either at 1450 °C or applying 200 V cm−1 electric field at 800 °C, 900 °C and 1000 °C. The structural phases and the microstructure of the sintered pellets were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The formation of substitutional solid solution was followed by monitoring the increase of the electrical conductivity by impedance spectroscopy and X-ray diffraction. The main results show that Joule heating due to the flow through the pellets of the electric current, which was produced by the application of the electric field, allows for promoting partial solid solution as well as partial sintering the ceria-gadolinia pellets. Moreover, grain growth that occurred in the high temperature sintered pellets was inhibited in the electric field-assisted synthesized/sintered pellets, being an alternative technique for producing cerium oxide-gadolinium oxide solid solutions.

    Palavras-Chave: cerium oxides; sintering; powders; electrical properties; synthesis; gadolinium oxides

  • IPEN-DOC 28329

    RIBEIRO, RICARDO da C.; KINOSHITA, ANGELA; ARAUJO-JUNIOR, HERMINIO I.; FIGUEIREDO, ANA M.G. ; CARVALHO, ISMAR de S.; BAFFA, OSWALDO. ESR dating of Toxodon teeth from Baixa Grande, Bahia, Brazil. Journal of South American Earth Sciences, v. 112, p. 1-6, 2021. DOI: 10.1016/j.jsames.2021.103616

    Abstract: Although the extinct Quaternary megafauna is widely recorded in northeastern Brazil, geochronological studies carried out on its fossiliferous deposits are still scarce. In this study, Electron Spin Resonance (ESR) was applied to date 12 tooth fragments of Toxodon platensis (Mammalia, Notoungulata) collected in the tank deposit of Lago do Rumo, Baixa Grande, state of Bahia, Brazil. The results obtained in the geochronological analysis performed here reveal ages from around 60 ka to 34 ka for T. platensis in Lagoa do Rumo; and, considering the integration data in the paleontological literature, our results evidence the largest time-averaging ever recorded for tank deposits: around 51 thousand years.

  • IPEN-DOC 28328

    FERREIRA, ANDREI M.; MARTORANO, MARCELO A.; LIMA, NELSON B. de ; PADILHA, ANGELO F.. Effects of recovery and recrystallization on microstructure and texture during annealing of a cold deformed superconducting Nb-50(wt.)%Ti alloy. Journal of Alloys and Compounds, v. 887, p. 1-9, 2021. DOI: 10.1016/j.jallcom.2021.161334

    Abstract: A Nb-50(wt.)%Ti alloy was melted and remelted in an electron beam furnace and the cast ingot was subsequently deformed into a bar by cold swaging, undergoing a maximum reduction in the area of 90%. Samples of the cold deformed bar were subjected to isochronous annealing cycles for 1 h in the temperature range between 250 and 1000 °C. The microstructural changes of the samples were monitored by optical microscopy, scanning electron microscopy with backscattered electron diffraction (EBSD), X-ray diffraction for pattern and texture determinations, and Vickers microhardness measurements. Recovery is the main softening mechanism in the samples annealed at temperatures up to 600 °C, but recrystallization is significant at temperatures equal to or above 750 °C and might also contribute to softening. Grain growth is also noted after annealing at the temperatures of 900 °C and 1000 °C. The microstructures of the cold deformed sample and of the samples annealed at temperatures up to 600 °C display a curly structure caused by deformation bands and their dislocation substructures. At the annealing temperatures of 900 °C and 1000 °C, complete recrystallization occurs and eliminates the deformation bands, but the curly pattern still exists and is probably due to a residue of the microsegregation of elements that occurs during solidification of the ingot. An intense fiber texture that is typical of cold swaging is observed in the cold deformed sample and in those annealed at temperatures up to 750 °C, but annealing at temperatures of 900 °C and 1000 °C weakens this texture owing to complete recrystallization. The results of the present work show the importance of the strong interactions among the phenomena of recovery, recrystallization, and microsegregation in determining the microstructure and texture of cold deformed and annealed Nb-Ti alloys.

  • IPEN-DOC 28327

    GASPER, RENATO R. ; SOMESSARI, SAMIR L. ; SPRENGER, FRANCISCO E. ; FEHER, ANSELMO ; DUARTE, CELINA L. ; SAMPA, MARIA H. de O. ; LAINETTI, FABIANA de F. ; BRAGA, ALCIDES; RODRIGUES, MARCOS de M.; CALVO, WILSON A.P. . Developing an electrical power system of a mobile electron beam accelerator to treat wastewater and industrial effluents / Desenvolvimento de um sistema de energia elétrica de um acelerador móvel de feixe de elétrons para tratar águas residuais e efluentes industriais. Brazilian Journal of Development, v. 7, n. 11, p. 102366-102379, 2021. DOI: 10.34117/bjdv7n11-046

    Abstract: The treatment of wastewater and industrial effluents by electron beam irradiation is a promising technique, however, not very widespread in Brazilian territory. The design and construction of a mobile unit by the Nuclear and Energy Research Institute, containing an electron beam accelerator of 700 keV and 20 kW is innovative to demonstrate the effects and positive results of this technology. The aim is to transfer the mobile unit to several companies with interest in liquid waste treatment, connect to the industry electrical system and start the ionization treatment process through electron beam. The mobile unit connection to the local electrical system may be a challenge due to the great diversity of voltages and distances involved, as well as the large injections of harmonic content generated by the electron beam accelerator that can affect sensitive loads in the industrial system. In this work, an analysis of the electrical power system of the mobile unit was made, regarding the interruption capacity, selectivity protection and adequate short circuit levels, in order to assure a greater reliability in the operation. At the end, the control panel of the mobile unit, simulations and measurements were carried out at the 1.5 MeV and 37.5 kW electron beam accelerator, installed in the Radiation Technology Center, demonstrating the necessity of applying a filter to reduce the measured harmonic distortion. The analysis of the mobile unit electrical power system was made, in order to assure a greater reliability in the operation.

  • IPEN-DOC 28326

    CANAZZA, SAMUEL A.; GONCALVES, SILAS A.; COSTA, FABIO E. da ; HAMADA, MARGARIDA M. . Desenvolvimento de detector portátil de radiação usando simultaneamente fotodiodo de silício para raios-x e cintilador com fotodiodo para raios gama / Development of a portable radiation detector using simultaneous silicon photodiode for x-rays and scintilator with photodiode for gamma rays. Brazilian Journal of Development, v. 7, n. 9, p. 90975-90984, 2021. DOI: 10.34117/bjdv7n9-315

    Abstract: Neste trabalho foi desenvolvido um detector portátil de radiação usando como meio detector um fotodiodo de silício para raios-X e um cintilador de CsI(Tl) com fotodiodo para radiação gama. A configuração dos detectores foi estudada utilizando fotodiodos em paralelo com um único pré-amplificador e com pré-amplificadores em paralelo, buscando o menor ruído do conjunto e com isso aumentar a faixa de energias detectadas.

  • IPEN-DOC 28325

    YOVANOVICH, MARCOS ; SILVA, ARACELI J. da ; SOUZA, RODRIGO F.B. de ; USSUI, VALTER ; NETO OLIVEIRA, ALMIR ; LAZAR, DOLORES R.R. . Conversion of methane to methanol using WO3/TiO2 porous photocatalyst. International Journal of Electrochemical Science, v. 16, n. 7, p. 1-14, 2021. DOI: 10.20964/2021.07.65

    Abstract: The conversion of methane into methanol is one of the great challenges in the photocatalysis. In this investigation WO3/TiO2 photocatalysts was synthesized by sodium borohydride (NaBH4) method. The tungsten concentration was studied in the range of 5 to 20 atomic ratio. XRD results revealed a TiO2 anatase phase and WO3 peaks near the background noise. However, WO3 presence has been highlighted by Raman spectroscopy, indicating the existence of both orthorhombic and amorphous phase.The photocatalyst experiments showed that all materials enable the methanol production in UVC irradiation, and only the materials with WO3 content produced the alcohol in white light irradiation. The high conversion was observed for WO3(10)/TiO2(90) with 3.5 mmol h-1. The conversion of methane to methanol was most promising using WO3(10)/TiO2(90) due high conversion and no other products observed in FTIR spectra.

  • IPEN-DOC 28324

    SOUZA, ARMANDO C. de; ARISTONE, FLAVIO; GOUVEA, ADRIANA F.G.; FERNANDES, HEDIELLY B.; MIYAI, ADAILTO; ROSSI, JESUALDO . Characterization and measurement of gamma radiation shielding of a new tungsten-lignin composite. Journal of Composite Materials, v. 55, n. 24, p. 3579-3588, 2021. DOI: 10.1177/00219983211029364

    Abstract: This research has been carried on to analyze the capability of a new composite to be effectively used as shielding of gamma radiation. The preparation of a metal-organic composite formed by tungsten and Kraft lignin is presented. Samples have been characterized through X-rays and scanning electron microscopy measurements. The results led to the study of the different phase formations. The microscopic analyzes indicate that two different phases are present in the composite. The absence of oxidation in the process even after the temperature treatment imposed to form the sample has also been noticed. Measurements of the attenuation have been performed to study its ability to absorb gamma radiation. A sample of cobalt 60 (Co-60), for which the peak energies are at 1173 keV and 1332 keV, was used as a source of gamma radiation in the experiment of attenuation. The measured attenuation of gamma radiations when the composite is placed to act as a shield is only 16% smaller than the attenuation obtained for standard pure tungsten. This is a clear indication that the new metal-organic composite is suitable for the fabrication of devices dedicated to shielding radiation, with the advantage of being easier to manipulate.

  • IPEN-DOC 28323

    IZIDORO, JULIANA de C. ; FUNGARO, DENISE A. ; VIVIANI, LUCIANA C.; SILVA, ROGERIO da C.. Brine sludge waste from a Chlor-alkali industry: characterization and its application for non-structural and structural construction materials. Journal of Applied Materials and Technology, v. 3, n. 1, p. 1-7, 2021. DOI: 10.31258/Jamt.3.1.1-7

    Abstract: Brine sludge (BS) is an industrial waste generated in large amounts by the Chlor-alkali industry and, usually disposed into industrial landfills. Because BS contains several chemical compounds, also presents a potential environmental impact. The feasibility of the utilization of brine sludge wastes for the preparation of value-added materials was investigated. The characterization of two brine sludge samples was performed in terms of chemical and physical composition, particle size distribution, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and thermal analysis (DTA/TG). Elements like Ca, Si, Na, Mg, Al, Cl, and Fe were identified in the samples. The XRD results confirmed the crystalline nature of compounds and indicated that the main compounds in brine sludge samples were calcium carbonate, sodium chloride, magnesium hydroxide, and quartz. FTIR showed the presence of varying functional groups like carbonate, siloxane, and hydroxide. The two brine sludge samples can be considered as a fine powder with the mean diameter (d50) of 4.984 µm and 24.574 µm, for the BS from Santo André and Cubatão, respectively. The results indicated that the brine sludge samples presented favorable characteristics to use limestone ?ller and binder alternative to Portland cement in the nonstructural construction materials. The incorporation of brine sludge in geopolymeric materials is another possible use in sustainable construction material products. The production of value-added products from brine sludge will be an important contribution towards sustainable development adopted by the Chlor-alkali industry.

  • IPEN-DOC 28322

    ALVES, MAURICIO B. ; EMERENCIANO, ANDREWS K.; BORDON, ISABELLA C.A. da C.; SILVA, JOSE R.M.C.; FAVARO, DEBORAH I.T. ; BORGES, JOAO C.S.; BORGES, RICARDO M.; PINTO, JOANA M. e; RESENDE, KARINA F.O.; DZIK, LUCIANA M.. Biomonitoring Assessment of Toxic and Trace Elements in Sterechinus neumayeri Sea Urchins from the Comandante Ferraz Station in Antarctica. Bulletin of Environmental Contamination and Toxicology, v. 107, n. 1, SI, p. 11-19, 2021. DOI: 10.1007/s00128-021-03307-3

    Abstract: In the present study, sea urchin Sterechinus neumayeri tissues were used for the passive biomonitoring of toxic and trace elements at the Comandante Ferraz Station, Antarctica and compared to a pristine region (Botany). As, Ba, Br, Ca, Co, Cr, Fe, K, Na, Rb, Sc, Se and Zn concentrations were determined by instrumental neutron activation analysis (INAA), while toxic metals (Cd, Hg, Ni and Pb), and Cu were determined by atomic absorption spectrometry (GF-AAS). The findings were compared to other organisms commonly applied for biomonitoring purposes and to the sediment concentrations of each sampling region. Urchins from the Ferraz Station area presented higher Br, Co, Cr, Cs, K, Se and Zn levels than the pristine location. The results obtained herein suggest S. neumayeri can be applied to the biomonitoring of Cr and Zn. The present study also contributes to knowledge of the mineral composition of the sea urchin S. neumayeri.

  • IPEN-DOC 28321

    BORGES, ROGER; KAI, KAREN C.; LIMA, CASSIO A. ; ZEZELL, DENISE M. ; ARAUJO, DANIELE R. de; MARCHI, JULIANA. Bioactive glass/poloxamer 407 hydrogel composite as a drug delivery system: The interplay between glass dissolution and drug release kinetics. Colloids and Surfaces B: Biointerfaces, v. 206, p. 1-11, 2021. DOI: 10.1016/j.colsurfb.2021.111934

    Abstract: Since patients suffer pain in the post-surgery of bone repair interventions, bioactive glass/hydrogel drug delivery systems containing local anesthetics, such as ropivacaine, could improve patient life quality by combining bone regeneration with anesthetics. However, poloxamer-based hydrogel properties are sensitive to ions, temperature, and water contents and could be structurally influenced by the ionic dissolution products from bioactive glasses of different compositions. Therefore, this study evaluated the interplay between bioactive glass dissolution kinetics and poloxamer 407 properties, establishing a correlation between changes in the hydrogel and drug release kinetics. Three glass compositions were produced, yielding Ca-rich, Na-rich, and an intermediate glass composition. The influence of Ca/Na ratios on the glass structure and dissolution was investigated. Further, the glasses and ropivacaine were incorporated in the poloxamer hydrogel, and the self-assembly ability of poloxamer, the degradation rate, and the drug release kinetics of the composites were evaluated. The results suggested that glass connectivity affected the early-stage of glass dissolution, while sodium mobility influenced the long-term. The dissolution products from the glasses interact with the supramolecular structure of the poloxamer, causing structural changes responsible for hydrogel degradation. Consequently, by changing the Ca/Na ratio in the glasses, it is possible to modulate glass dissolution that, in turn, influences the ropivacaine release. Thus, we propose that the Ca/Na ratio in quaternary bioactive glasses can be used to modulate drug-delivery properties from systems based on bioactive glasses and poloxamer 407.

  • IPEN-DOC 28320

    BIANCOLLI, ANA L.G. ; BSOUL-HAJ, SAJA; DOUGLIN, JOHN C.; BARBOSA, ANDREY S. ; SOUSA JUNIOR, ROGERIO R. de; RODRIGUES JUNIOR, ORLANDO ; LANFREDI, ALEXANDRE J.C.; DAKEL, DARIO R.; SANTIAGO, ELISABETE I. . High-performance radiation grafted anion-exchange membranes for fuel cell applications: Effects of irradiation conditions on ETFE-based membranes properties. Journal of Membrane Science, v. 641, p. 1-12, 2022. DOI: 10.1016/j.memsci.2021.119879

    Abstract: Anion-exchange membrane fuel cells (AEMFCs) are rapidly gaining visibility in the clean energy research field due to their high power output and potential to significantly reduce materials costs. However, despite the high performances obtained, in-operando stability still presents a major obstacle for this technology. The durability issues are usually attributed to the core component of the AEMFCs - the anion-exchange membrane (AEM). An easy and simple way to produce these AEMs is through radiation grafting. Radiation-induced processes involve changes in the intrinsic properties of the polymer that can promote both crosslinking and chain scissioning, which may directly affect the mechanical properties and durability of AEMs. This study presents a comprehensive report of the effects of irradiation on the final properties of electron-beam grafted ETFE-AEMs. The results strongly suggest that low absorbed doses (<40 kGy) and an inert atmosphere (N2) should be used during the irradiation process in order to obtain better backbone stability and, consequently, AEMFC durability, considering ETFE-based AEMs.

  • IPEN-DOC 28319

    BATISTA, WILSON O.; SOARES, MARIA R. ; RIOS, JACQUELINE M.G.; SOUZA, ANTONIO C dos S.; PINHEIRO, ISABELLE M.; RAMIREZ, JOSE L.J.V.; CALDAS, LINDA V. E. . Assessment of scattered radiation from hand-held dental x-ray equipment using the Monte Carlo method. Journal of Radiological Protection, v. 41, n. 4, p. 654-668, 2021. DOI: 10.1088/1361-6498/abf3cd

    Abstract: The objective of the present study was to evaluate the intensity and spatial distribution of the scattered radiation caused by the use of hand-held x-ray equipment in the zone occupied by the operator, using the Monte Carlo simulation for radiographic views of the upper and lower incisor teeth, and the consequent evaluation of the equivalent dose in the lens. In order to carry out this evaluation, the geometry of a typical dental facility with plaster walls containing the scattering object was used for the computational scenario implemented for the Monte Carlo method simulation. The PENELOPE code for Monte Carlo simulation of electron and photon transport was used with the radiation beam represented by a 60 kV spectrum, 1.5 mm Al and tungsten target. The simulations were carried out with typical parameters for workload and the number of radiographs/week. The results showed that the exposure levels varied significantly according to the angle of the x-ray beam and with the distance to the scattering object. It is concluded that the incorporation of hand-held equipment in dental radiology must be accompanied by the surveillance of occupational exposure levels and a review of the training structure of professionals in dental radiology regarding aspects of radiological protection and the particularities of using this type of equipment.

  • IPEN-DOC 28318

    SILVA, DANIEL J. da; PARRA, DUCLERC F. ; WIEBECK, HELIO. Applying confocal Raman spectroscopy and different linear multivariate analyses to sort polyethylene residues. Chemical Engineering Journal, v. 426, p. 1-13, 2021. DOI: 10.1016/j.cej.2021.131344

    Abstract: High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polypropylene (PP), and recycled Poly(Ethylene Terephthalate) (PET) are widely applied as packaging materials worldwide, and they correspond to more than 50 % of the plastic residues present in municipal solid waste. Currently, it is needed to develop effective methods to ensure the identification and sorting of plastic waste to guarantee necessary purity to obtain quality and economically viable recycled goods from post-consumer plastic. As an attempt to that, we investigated the applicability of Confocal Raman Scattering Spectroscopy (Confocal Raman) combined with Principal Component Analysis (PCA), Linear Partial Least Squares Regression by Intervals (iPLS-R) and Competitive Adaptive Weighted Sampling (CARS/PLS-R) as fast chemometric tools to identify and classify pristine and recycled mixtures of HDPE and LDPE from municipal solid waste in São Paulo, Brazil. We found several limitations in applying this procedure to classify the different polyethylenes and their polymer blends using the Principal Components (PC) from PCA analysis. iPLS-R regression model presents more effectiveness than the CARS/PLS-R model to detect the LDPE content in recycled HDPE/LDPE blends, both being influenced by different contaminants (PP, PET, SiO2, and CaCO3) added in these recycled plastics.

  • IPEN-DOC 28317

    FERNANDEZ, A.P.R. ; PERIGO, E.A.; FARIA, R.N. . Analytical expressions for electrochemical supercapacitor with potential dependent capacitance. Journal of Energy Storage, v. 43, p. 1-11, 2021. DOI: 10.1016/j.est.2021.103156

    Abstract: Distinctly from ordinary capacitors which have a fixed capacitance, the capacitance of electrochemical supercapacitors is dependent on the applied potential. This feature introduces an additional complication to the analytical solution representing the supercapacitor circuit. Here a simplified equivalent circuit of electric double layer capacitors or electrochemical supercapacitors is proposed so that expressions evaluating the potential-dependent capacitance are derived considering short periods of charging and discharging process as in cyclic voltammetry carried out in a few minutes. Comparisons between such theoretical development and experimental cyclic voltammetry data – presenting a very good agreement – are presented and discussed.

  • IPEN-DOC 28316

    TESSARO, ANA P.G. ; ARAUJO, LEANDRO G. de ; TSUTSUMIUCHI, VICTOR K. ; OLIVEIRA JUNIOR, JULIO de ; VICENTE, ROBERTO . An algorithmic software model for the characterization of radioactive waste. Journal of Radioanalytical and Nuclear Chemistry, v. 330, n. 1, p. 279–292, 2021. DOI: 10.1007/s10967-021-07934-2

    Abstract: Non-consolidated information base, repetitive work, and data unreliability are some of the issues that may hamper a radioactive waste characterization program. Therefore, an algorithmic software model for the characterization of radioactive waste is proposed to boost waste management in nuclear-based facilities. The data obtained have enabled the construction of a guide code in the pseudotechnical language. The developed system fully covered the characterization stage, and met the needs identified in the radioactive waste management service. Here, we propose systematic documentation of the characterization methods that are employed during the radioactive waste management processes, besides formulating the system’s data recording.

  • IPEN-DOC 28315

    SELLERA, FABIO P.; SABINO, CAETANO P.; CABRAL, FERNANDA V. ; RIBEIRO, MARTHA S. . A systematic scoping review of ultraviolet C (UVC) light systems for SARS-CoV-2 inactivation. Journal of Photochemistry and Photobiology, v. 8, p. 1-6, 2021. DOI: 10.1016/j.jpap.2021.100068

    Abstract: A significant amount of epidemiological evidence has underlined that human-to-human transmission due to close contacts is considered the main pathway of transmission, however since the SARS-CoV-2 can also survive in aerosols, water, and surfaces, the development and implementation of effective decontamination strategies are urgently required. In this regard, ultraviolet germicidal irradiation (UVGI) using ultraviolet C (UVC) has been proposed to disinfect different environments and surfaces contaminated by SARS-CoV-2. Herein, we performed a systematic scoping review strictly focused on peer-reviewed studies published in English that reported experimental results of UVC-based technologies against the SARS-CoV-2 virus. Studies were retrieved from PubMed and the Web of Science database. After our criterious screening, we identified 13 eligible articles that used UVC-based systems to inactivate SARS-CoV-2. We noticed the use of different UVC wavelengths, technologies, and light doses. The initial viral titer was also heterogeneous among studies. Most studies reported virus inactivation in well plates, even though virus persistence on N95 respirators and different surfaces were also evaluated. SARS-CoV-2 inactivation reached from 90% to 100% depending on experimental conditions. We concluded that there is sufficient evidence to support the use of UVC-based technologies against SARS-CoV-2. However, appropriate implementation is required to guarantee the efficacy and safety of UVC strategies to control the COVID-19 pandemic.

  • IPEN-DOC 28177

    MACHADO, ALANA C.; CONFORTINI, GESSICA T.; VIANA, ITALLO E.L.; PEREIRA, LAIS G. de S.; PEREIRA, DAISA de L. ; ZEZELL, DENISE M. ; ARANHA, ANA C.C.; SCARAMUCCI, TAIS. A modified Er,Cr:YSGG laser protocol associated with fluoride gel for controlling dentin erosion. Lasers in Dental Science, v. 5, p. 177-183, 2021. DOI: 10.1007/s41547-021-00133-y

    Abstract: Propose Effective strategies to control the development of dental erosion are still needed. This study evaluated the effect of associating a modified Er,Cr:YSGG laser protocol with topical fluoride application on dentin erosion. Methods Sound and eroded dentin specimens (n = 10/substrate) were allocated into groups: control (no treatment); APF gel (1.23% F-, for 1 min, one application, removed with cotton roll); Er,Cr:YSGG laser P1 [0.25W, 20Hz, ≅ 6.5 J/cm2, 2 mm away from the surface, two irradiation of 10 s each, with sweeping movements, under 25% air, without water, with a sapphire tip measuring 750 μm in diameter and with of 6 mm (S75)]; Er,Cr:YSGG laser P2 (same settings with P1 except 1 mm away from the surface and ≅ 8.3 J/cm2); APF gel before Er,Cr:YSGG laser P1; APF gel before Er,Cr:YSGG laser P2. Specimens underwent a 5-day erosion-remineralization cycling. Erosion depth (surface loss — SL) was determined. Environmental scanning electron microscopy images (n = 2) were obtained. Data were statistically analyzed (α = 0.05). Results Sound substrate: APF gel presented lowest SL, differing significantly from control and other groups. Laser P1 and P2 had highest SL. Eroded substrate: laser P1 showed highest SL, differing significantly from all other groups. For the control, APF gel, and laser P1, the eroded substrates had significantly higher SL than the sound. For laser P2, SL from sound specimens was higher than the eroded. Melted areas were observed in the laser-treated groups. Conclusions Modified Er,Cr:YSGG laser parameter was unable to control progression of dentin erosion, not even when it was combined with fluoride.

  • IPEN-DOC 28173

    REIS, S.L. ; GROSSO, R.L. ; MUCCILLO, E.N.S. . Thermal and spectroscopic characterization of sol-gel-synthesized doped lanthanum gallate. Journal of Thermal Analysis and Calorimetry, v. 146, n. 4, p. 1561-1567, 2021. DOI: 10.1007/s10973-020-10113-2

    Abstract: In this study, a complex oxide solid solution consisting of lanthanum gallate with partial substitutions for strontium and magnesium (La0.9Sr0.1Ga0.8Mg0.2O2.85) was synthesized by the sol–gel route, aiming to obtain a sinter active powder and a final material that could be stoichiometrically controlled. The thermal behavior of the synthesized powder involves several steps of decomposition. The linear shrinkage of green compacts up to 1500 °C was 31%. The bulk conductivity of sintered specimens increases with sintering temperature up to 1400 °C. The stoichiometry was maintained for sintering temperatures up to 1450 °C. Elemental mapping obtained by energy-dispersive spectroscopy evidenced magnesium segregation at the grain boundaries. The overall results evidence the suitability of the synthesis method for preparing doped lanthanum gallate.

  • IPEN-DOC 28172

    SOUZA, ARMANDO C. ; ROSSI, JESUALDO L. ; TSAKIROPOULOS, PANOS; ARISTONE, FLAVIO. Microstructural evolution of the refractory WCuNi metallic alloy. Metals and Materials International, v. 27, n. 11, p. 4820-4830, 2021. DOI: 10.1007/s12540-020-00648-2

    Abstract: Science and technology of materials are widely interested in the development of new alloys involving tungsten due to its large applicability to the domain of nuclear material transportation. Tungsten is a refractory material and it has many applications in the nuclear industry due to its mechanical properties and excellent cross-section for thermal neutrons, being widely used for shielding of high-energy radiation. Some of the main elements added to tungsten forming alloys are Nb, Cr, Cu, Fe, Ni, Mo, Co, Sn, Ti, and Ta, which are responsible for modifications of the physical and chemical properties of the resulting alloy, interfering on the attenuation of gamma radiation. The main goal of this paper is to present a refractory alloy based on tungsten with embedded infiltrating elements like copper (Cu) and nickel (Ni) and characterize the microstructural evolution of different sintering process during its formation. Such a refractory alloy is submitted to the following characterization process: X-rays diffractometry, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy, and energy dispersive spectroscopy. The diffractometry exhibit typical standard results for the precursor powders: W, Cu, and Ni demonstrating high degrees of purity accordingly to the crystallographic determined parameters. The TGA for the powder W demonstrated thermal stability until 360 ºC, after an increase of mass due to the process of oxidation. The DSC analyze present two endothermal processes at temperatures 350 °C and 450 °C. The microstructural evolution of WCuNi samples presents the absence of oxidation, homogeneous morphology and stability of the binary phase α–β (W and CuNi respectively) for different sintering. These results shall be taken into consideration for future works, particularly on the study of shielding and gamma radiation attenuation.

  • IPEN-DOC 28171

    TAMAGAWA, HIROHISA; MULEMBO, TITUS; LIMA, VERA M.F. de ; HANKE, WOLFGANG. Analyses of HH and GHK equations with another perspective: can ion adsorption also govern trans-membrane potential?. Progress in Biophysics and Molecular Biology, v. 167, p. 3-11, 2021. DOI: 10.1016/j.pbiomolbio.2021.10.004

    Abstract: Two mathematically distinct physiological concepts, the Goldman-Hodgkin-Katz eq. (GHK eq.) and the Hodgkin-Huxley model (HH model) were successfully associated with each other in a prior work. The previous work was performed on the following premises (i) The membrane potential is generated by ion adsorption, as opposed to the classical ion transport mechanisms, (ii) The living cell is a thermodynamically real system rather than an ideal system, and (iii) The conductance employed in the HH model is replaced by the ion activity coefficient, which is weighted with the role of conductance. Consequently, the GHK eq. was mathematically associated with the HH model through the intermediary of Boltzmann ion distribution and mass action law. To verify if our theoretical formularization could afford a physiologically, physically and chemically viable model, we performed computational analysis using the formulae (quantitative correlations between various variables) we derived in the previous work. The computational results obtained through associating the GHK eq. with the HH model validated our model and its predictions. This outcome suggests that the current prevailing physiological concepts could be expanded further, to incorporate the newly proposed mechanisms. That is, GHK eq. and HH model could be interpreted via another set of founding principles that incorporate the ubiquitous phenomena of ion-adsorption.

  • IPEN-DOC 28170

    SGOUROS, O.; CAVALLARO, M.; CAPPUZZELLO, F.; CARBONE, D.; AGODI, C.; GARGANO, A.; DE GREGORIO, G.; ALTANA, C.; BRISCHETTO, G.A.; BURRELLO, S.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CHAVEZ LOMELI, E.R.; CIRALDO, I.; CUTULI, M.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FISICHELLA, M.; FOTI, A.; HACISALIHOGLU, A.; IAZZI, F.; LA FAUCI, L.; LINARES, R.; LUBIAN, J.; MEDINA, N.H.; MORALLES, M. ; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PINNA, F.; RUSSO, G.; GUAZZELLI, M.A.; SOUKERAS, V.; SOULIOTIS, G.; SPATAFORA, A.; TORRESI, D.; YILDIRIM, A.; ZAGATTO, V.A.B.. One-proton transfer reaction for the 18O+48Ti system at 275 MeV. Physical Review C, v. 104, n. 3, p. 034617-1 - 034617-12, 2021. DOI: 10.1103/PhysRevC.104.034617

    Abstract: Single-nucleon transfer reactions are processes that selectively probe single-particle components of the populated many-body nuclear states. In this context, recent efforts have been made to build a unified description of the rich nuclear spectroscopy accessible in heavy-ion collisions. An example of this multichannel approach is the study of the competition between successive nucleon transfer and charge exchange reactions, the latter being of particular interest in the context of single and double beta decay studies. To this extent, the one-proton pickup reaction 48Ti(18O, 19F) 47Sc at 275 MeV was measured for the first time, under the NUMEN experimental campaign. Differential cross-section angular distribution measurements for the 19F ejectiles were performed at INFN-LNS in Catania by using the MAGNEX large acceptance magnetic spectrometer. The data were analyzed within the distorted-wave and coupled-channels Born approximation frameworks. The initial and final-state interactions were described adopting the São Paulo potential, whereas the spectroscopic amplitudes for the projectile and target overlaps were derived from shell-model calculations. The theoretical cross sections are found to be in very good agreement with the experimental data, suggesting the validity of the optical potentials and the shell-model description of the involved nuclear states within the adopted model space.

    Palavras-Chave: matrix elements; nuclear matrix; charge-exchange reactions; double beta decay; cross sections

  • IPEN-DOC 28169

    SANTOS, O.C.B.; LICHTENTHALER, R.; PIRES, K.C.C.; UMBELINO, U.; ZEVALLOS, E.O.N.; LARA, A.L. de; SERRA, A.S.; SCARDUELLI, V.; ALCANTARA-NUNEZ, J.; GUIMARAES, V.; LEPINE-SZILY, A.; ZAMORA, J.C.; MORO, A.M.; APPANNABABU, S.; ASSUNCAO, M.; BARIONI, A.; LINARES, R.; ZAGATTO, V.A.B.; FARIA, P.N. de; MORAIS, M.C.; MORCELLE, V.; SHORTO, J.M.B. ; LEI, JIN. Evidence of the effect of strong stripping channels on the dynamics of the 8Li+58Ni reaction. Physical Review C, v. 103, n. 6, p. 064601-1 - 064601-10, 2021. DOI: 10.1103/PhysRevC.103.064601

    Abstract: The 8Li+58Ni collision is investigated at 23.9, 26.1, 28.7, and 30 MeV bombarding energies. Quasielastic angular distributions and the singles 7Li angular and energy distributions are presented. Coupled-reaction channels (CRC) calculations, which include the coupling of the elastic channel to 59Ni = 58Ni +n states above and below the neutron threshold, provide a simultaneous description of the quasielastic and transfer distributions and evidence the strong effect of the one-neutron transfer/breakup channels on the quasielastic scattering. The 7Li angular and energy distributions have been also successfully analyzed combining the continuum discretized coupled channels (CDCC) method, for the elastic breakup, and the IAV model of Ichimura, Austern, and Vincent [Phys. Rev. C 32, 431 (1985)], for the nonelastic breakup. These calculations indicate that most of the 7Li yields are due to nonelastic breakup contributions (transfer), whereas elastic breakup plays a minor role.

    Palavras-Chave: lithium 8 reactions; nickel 58 reactions; stripping; coupled channel theory; lithium 7

  • IPEN-DOC 28168

    FERREIRA, W.L. ; PEREIRA, L.F.D. ; LEITE NETO, O.F.S. ; MACIEL, L.S. ; GONÇALVES, V.C. ; SAXENA, R.N. ; CARBONARI, A.W. ; COSTA, M.S.; CABRERA-PASCA, G.A.. Locally symmetric oxygen vacancy around Cd impurities in CeO2. Physical Review B, v. 104, n. 3, p. 035146-1 - 035146-11, 2021. DOI: 10.1103/PhysRevB.104.035146

    Abstract: A detailed investigation of the electronic structure in the neighborhood of Cd impurities in CeO2 has been performed by ab initio calculations to elucidate the interplay between the oxygen vacancies and electric quadrupole interactions. The quadrupole frequency related to the major component of the electric-field gradient (EFG) at impurities sites from its neighboring charge density as well as its symmetry were calculated by simulating oxygen vacancies at oxygen nearest neighbor of Cd. Results show a very good agreement with experimental hyperfine interactions measurements at the 111Cd nucleus replacing Ce at CeO2. A systematic mapping of oxygen vacancies in CeO2 supercells was proposed within the framework of density-functional theory using the WIEN2K code focusing on the electronic distribution in the vicinity of Cd impurities. Results show that the calculated values of EFG crucially depend on impurity-vacancy complex position and the striking axial symmetry observed when an oxygen monovancy is at the nearest neighborhood of Cd is explained by a rearrangement of its p orbitals.

    Palavras-Chave: electric fields; cadmium; cerium oxides; x-ray spectra

  • IPEN-DOC 28167

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de . Novel technological developments with impacts on perspectives for mobile nuclear power plants. World Journal of Nuclear Science and Technology, v. 11, n. 4, p. 141-158, 2021. DOI: 10.4236/wjnst.2021.114011

    Abstract: New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.

    Palavras-Chave: nuclear power plants; nuclear facilities; mobile reactors; thermonuclear reactors; energy sources; nuclear merchant ships

  • IPEN-DOC 28166

    DEL-VALLE, MATHEUS ; SANTOS, MOISES O. dos ; SANTOS, SOFIA N. dos ; CASTRO, PEDRO A.A. de ; BERNARDES, EMERSON S. ; ZEZELL, DENISE M. . The impact of scan number and its preprocessing in micro-FTIR imaging when applying machine learning for breast cancer subtypes classification. Vibrational Spectroscopy, v. 117, p. 1-6, 2021. DOI: 10.1016/j.vibspec.2021.103309

    Abstract: The breast cancer molecular subtype is an important classification to outline the prognostic. Gold-standard assessing using immunohistochemistry adds subjectivity due to interlaboratory and interobserver variations. In order to increase the diagnosis confidence, other techniques need to be examined, where the FTIR spectroscopy imaging allied with machine learning techniques may provide additional and quantitative information regarding the molecular composition. However, the impact of co-added scans acquisition parameter into machine learning classifications still needs better evaluation. In this study, FTIR images of Luminal B and HER2 subtypes were acquired varying the scan number and preprocessing techniques. It was demonstrated a spectral quality improvement when the scan number was increased, decreasing the standard deviation and outliers. Six machine learning models were used to classify the subtypes: Linear Discriminant Analysis, Partial Least Squares Discriminant Analysis, K-Nearest Neighbors, Support Vector Machine, Random Forest and Extreme Gradient Boosting. Best mean accuracy of 0.995 was achieved by Extreme Gradient Boosting model. It was found that all models achieved similar high accuracies with groups b256_064 (256 background and 064 scans), b256_128 and b128_128. Besides assessing the performance of different models, the b256_064 was established as the optimal group due to the minimum acquisition time. Therefore, this work indicates b256_064 for breast cancer subtype classification and also as a basis for other studies using machine learning for cancer evaluation.

    Palavras-Chave: fourier transform spectrometers; mammary glands; neoplasms; machine learning; histological techniques

  • IPEN-DOC 28165

    DONATO, MARESSA ; SOTO, CARMEN; LANIO, MARIA E.; ITRI, ROSANGELA; ALVAREZ, CARLOS. The pore-forming activity of sticholysin I is enhanced by the presence of a phospholipid hydroperoxide in membrane. Toxicon, v. 204, p. 44-55, 2021. DOI: 10.1016/j.toxicon.2021.10.012

    Abstract: Sticholysin I (StI) is a pore-forming toxin (PFT) belonging to the actinoporin protein family characterized by high permeabilizing activity in membranes. StI readily associates with sphingomyelin (SM)-containing membranes originating pores that can lead to cell death. Binding and pore-formation are critically dependent on the physicochemical properties of membrane. 1-palmitoyl-2-oleoylphosphatidylcholine hydroperoxide (POPC–OOH) is an oxidized phospholipid (OxPL) containing an –OOH moiety in the unsaturated hydrocarbon chain which orientates towards the bilayer interface. This orientation causes an increase in the lipid molecular area, lateral expansion and decrease in bilayer thickness, elastic and bending modulus, as well as modification of lipid packing. Taking advantage of membrane structural changes promoted by POPC-OOH, we investigated its influence on the permeabilizing ability of StI. Here we report the action of StI on Giant Unilamellar Vesicles (GUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and SM containing increasing amount of POPC-OOH to assess vesicle permeability changes when compared to OxPL-lacking membranes. Inclusion of POPC-OOH in membranes did not promote spontaneous vesicle leaking but resulted in increased membrane permeability due to StI action. StI activity did not modify the fluid-gel phase coexistence boundaries neither in POPC:SM or POPC-OOH:SM membranes. However, the StI insertion mechanism in membrane seems to differ between POPC:SM and POPC-OOH:SM mixtures as suggested by changes in the time course of monolayer surface tension measurements, even though a preferable binding of the toxin to OxPL-containing systems could not be here demonstrated. In summary, modifications in the membrane imposed by lipid hydroperoxidation favor StI permeabilizing activity.

    Palavras-Chave: phospholipids; hydrogen peroxide; cell membranes; antimitotic drugs; toxins; phase transformations

View more

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.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

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

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