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  • IPEN-DOC 30179

    QUEIROZ, FERNANDA M.; RIBEIRO, GLEICY de L.X.; CASTRO, RENATO S. de; SANTOS, ROGERIO G. dos; VIEIRA, ALEXANDRE ; TERADA, MAYSA; BUGARIN, ALINE de F.S.; ROSSI, WAGNER de ; COSTA, ISOLDA . Study of the effect of nanosecond laser texturing on the corrosion behavior of Ti6Al4V and Ti6Al4V parts produced by powder bed fusion. Materials Performance and Characterization, v. 12, n. 3, p. 341-350, 2023. DOI: 10.1520/MPC20220109

    Abstract: Combining metallic additive manufacturing with laser texturing could be an alternative in obtaining parts with functional hydrophilic surfaces, which improves osteointegration. Careful study of the corrosion behavior of the surfaces obtained is necessary, because the evolution of this phenomenon can influence the osteointegration of the implant, causing the release of metal ions in the body and even the rejection of the component. This study compared the corrosion behavior of laser texturing Ti6Al4V components with components manufactured using laser power bed fusion of the same alloy followed by laser texturing. Their microstructure, roughness, wettability, and electrochemical behavior were analyzed, and different morphologies and microtopographies were observed comparing both samples. The electrochemical tests obtained indicate that Ti6Al4V showed higher corrosion resistance than L-PBF Ti6Al4V after laser texturing. The results suggest that laser texturing can encourage cell proliferation and osseointegration on the surface of Ti6Al4V biomedical implants.

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  • IPEN-DOC 30180

    SANTOS, JHONATHA R. dos ; BUENO, PATRICIA; JAKUTIS, JONAS; VICTOR, ALESSANDRO R.; BARRETA, LUIZ F.N.; SBAMPATO, MARIA E.; NERI, JOSE W.; SILVEIRA, CARLOS A.B.; RODRIGUES, NICOLAU A.S.; DESTRO, MARCELO G.. Dysprosium optogalvanic spectroscopy in a hollow cathode lamp. Journal of the Optical Society of America B, v. 40, n. 5, p. 1141-1147, 2023. DOI: 10.1364/JOSAB.482663

    Abstract: This work presents data obtained from optogalvanic spectroscopy (OGS) of dysprosium (Dy) using a commercial hollow cathode lamp. Combining laser beams from two tunable dye lasers, it was possible to identify 13 electronic transitions from excited states of the atom not observed or registered in published papers and the NIST database; these lines were observed between 555–575 nm and 585–615 nm. The study of 13 two-step transitions found in this work complement the available data for the Dy which may support other research or any work using this atom.

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  • IPEN-DOC 30178

    SILVA, BRUNO L. da; CARMINATI, SAULO A. ; SOUZA, MATHEUS B.C.; SOARES, LEONARDO C.; LONGO, CLAUDIA; FERNANDEZ, PABLO S.; NOGUEIRA, ANA F.. Photoelectrochemical conversion of glycerol aqueous solution to value-added chemicals using Bi2Fe4O9 as a photoanode. Sustainable Energy and Fuels, v. 7, n. 23, p. 5546-5556, 2023. DOI: 10.1039/d3se01045g

    Abstract: A low-cost, stable and non-toxic Bi2Fe4O9 (BFO) photoanode was used for the first time to promote glycerol aqueous solution photoelectrochemical conversion to hydrogen and value-added chemicals. Photoelectrochemical measurements were performed under AM1.5G irradiation using a three-electrode cell. The best performance was achieved in alkaline medium, where four distinct glycerol oxidation products were detected (glycerate, formate, glycolate and lactate). In neutral medium, no oxidation products were detected. In acidic medium, we observed an improved selectivity, with only glyceraldehyde and dihydroxyacetone as oxidation products. Our results show that the electron–hole recombination, which restricts the efficiency of glycerol conversion, is one of the main shortcomings of BFO. However, its high open circuit potential (OCP) value and several other desirable properties for a good photoelectrocatalyst make it a material worth further research.

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  • IPEN-DOC 30177

    MOLDONADO, EDISON P.; SAMAD, RICARDO E. ; ZUFFI, ARMANDO V.F. ; SANTOS, JHONATHA R. dos ; VIEIRA JUNIOR, NILSON D. . Impact of He+N2 concentration on self-modulated laser wakefield acceleration driven by pulses of a few TW. Journal of the Optical Society of America B, v. 40, n. 4, p. C141-C147, 2023. DOI: 10.1364/JOSAB.482305

    Abstract: Laser wakefield electron acceleration with ionization injection has rarely been studied in the low-power, selfmodulated case. We performed simulations of such regimes using a mixture of He and N2 gases and driven by laser pulses with peak powers around 1 TW. Analyses show the generation of electron bunches with an average energy of up to 70 MeV, an energy spread as low as 18%, and an emittance as good as a fraction of a mm mrad. The obtained electron beam parameters lead to several trade-offs as a function of N2 concentration, allowing for many different designs.

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  • IPEN-DOC 30176

    MACHADO, MARINA ; TABUTI, F. ; PIAZZOLLA, F. ; MORAES, T. ; ABE, R.; GUIMARAES, R.M.; MIURA, Y.; FUKUYAMA, Y.; FONSECA, F.C. . Steam reforming catalytic layer on anode-supported and metal-supported solid oxide fuel cells for direct ethanol operation. ECS Transactions, v. 111, n. 6, p. 301-311, 2023. DOI: 10.1149/11106.0301ecst

    Abstract: A catalyst based on lanthanum chromite with exsolved metallic ruthenium nanoparticles (LaCrO3-Ru) was applied as a catalytic layer for internal ethanol steam reforming of anode-supported and metal-supported solid oxide fuel cells. The metal support exhibits limited catalytic properties for the ethanol steam reforming reaction. Thus, the LaCrO3-Ru catalysts were optimized for operating temperatures in the 600-700 °C range to promote stable ethanol reforming. The catalytic layer had no significant impact on the electrochemical properties of the fuel cell, and samples with and without the catalytic layer exhibited similar performance in hydrogen. Initial durability tests with LaCrO3-Ru layer have shown that the catalytic layer plays a crucial role in the stability of the metal-supported fuel cell under ethanol.

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  • IPEN-DOC 30175

    MALDONADO, EDISON P.; SAMAD, RICARDO E. ; ZUFFI, ARMANDO V.F. ; VIEIRA JUNIOR, NILSON D. . Simulation of self-modulated laser wakefield acceleration using few TW in downramp injection and ionization injection regimes. Applied Optics, v. 62, n. 12, p. 3202-3207, 2023. DOI: 10.1364/AO.477401

    Abstract: Simulations of transitional self-modulated laser wakefield acceleration driven by laser pulses of a few terawatts are discussed, comparing a downramp-based injection regime with an ionization injection regime. We demonstrate that a configuration using an N2 gas target and a laser pulse of ∼75mJ with ∼2TW peak power is a good alternative as a high repetition rate system that produces electrons of many tens of MeV, pC charge, and emittance of the order of 1 mm mrad.

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  • IPEN-DOC 30174

    ZUFFI, ARMANDO V.F. ; SANTOS, JHONATHA R. dos ; MALDONADO, EDISON P.; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Femtosecond laser-plasma dynamics study by a time-resolved Mach–Zehnder-like interferometer. Applied Optics, v. 62, n. 8, p. C128-C134, 2023. DOI: 10.1364/AO.477395

    Abstract: Side-view density profiles of a laser-induced plasma were measured by a home-built, time-resolved, Mach–Zehnder-like interferometer. Due to the pump-probe femtosecond resolution of the measurements, the plasma dynamics was observed, along with the pump pulse propagation. The effects of impact ionization and recombination were evidenced during the plasma evolution up to hundreds of picoseconds. This measurement system will integrate our laboratory infrastructure as a key tool for diagnosing gas targets and laser-target interaction in laser wakefield acceleration experiments.

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  • IPEN-DOC 30173

    MOYA, MURILO T.M.; ARAUJO, LEANDRO G. de ; LOPES, FERNANDO S.; TEIXEIRA, ANTONIO C.S.C.. TiO2 P25 and Kronos vlp 7000 materials activated by simulated solar light for atrazine degradation. International Journal of Chemical Reactor Engineering, v. 21, n. 10, p. 1211-1223, 2023. DOI: 10.1515/ijcre-2022-0186

    Abstract: Photocatalysis-based technologies have been proposed for the treatment of wastewater containing atrazine (ATZ), a persistent and recalcitrant pollutant. This study aims to evaluate and compare the efficiency of TiO2 P25 and TiO2 modified with carbon (C–TiO2 Kronos vlp 7000) in the photocatalytic degradation of ATZ in aqueous systems. The experiments were performed in a tubular photochemical reactor equipped with a compound parabolic collector (CPC) irradiated by simulated solar light. The materials were characterized by X-ray diffraction, infrared spectroscopy, BET specific surface area, and diffuse reflectance spectroscopy. For TiO2 P25, ATZ removals varied in the range 86–100 % after 120 min of irradiation, although the total organic carbon (TOC) analyses indicated that no significant ATZ mineralization occurred (<20 %). C–TiO2 Kronos vlp 7000, on the other hand, was not able to completely remove ATZ after 120 min of irradiation. In this case, pesticide removals were 37–45 % over 120 min, while C–TiO2 performed better with regard to ATZ mineralization, with 38 % TOC removal. Given the low mineralization of atrazine, the intermediate compounds formed were identified for each photocatalytic material.

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  • IPEN-DOC 30037

    BERECZKI, ALLAN ; DIPOLD, JESSICA ; FREITAS, ANDERSON Z. ; WETTER, NIKLAUS U. . Sub-10 nm nanoparticle detection using multi-technique-based micro-raman spectroscopy. Polymers, v. 15, n. 24, p. 1-17, 2023. DOI: 10.3390/polym15244644

    Abstract: Microplastic pollution is a growing public concern as these particles are ubiquitous in various environments and can fragment into smaller nanoplastics. Another environmental concern arises from widely used engineered nanoparticles. Despite the increasing abundance of these nanosized pollutants and the possibility of interactions with organisms at the sub cellular level, with many risks still being unknown, there are only a few publications on this topic due to the lack of reliable techniques for nanoparticle characterization. We propose a multi-technique approach for the characterization of nanoparticles down to the 10 nm level using standard micro-Raman spectroscopy combined with standard atomic force microscopy. We successfully obtained single-particle spectra from 25 nm sized polystyrene and 9 nm sized TiO2 nanoparticles with corresponding mass limits of detection of 8.6 ag (attogram) and 1.6 ag, respectively, thus demonstrating the possibility of achieving an unambiguous Raman signal from a single, small nanoparticle with a resolution comparable to more complex and time-consuming technologies such as Tip-Enhanced Raman Spectroscopy and Photo-Induced Force Microscopy

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  • IPEN-DOC 30036

    MUNOZ, PATRICIO; ILAVSKY, JAN; NEWVILLE, MATTHEW; WETTER, NIKLAUS U. ; LOURENÇO, RAFAEL A.; ANDRADE, MARCELO B. de; MARTINS, TEREZA S.; DIPOLD, JESSICA ; FREITAS, ANDERSON Z. ; SILVA, LUIS C.C. da; OLIVEIRA, CRISTIANO L.P.. (U)SAXS characterization of porous microstructure of chert: insights into organic matter preservation. Journal of Applied Crystallography, v. 56, Part: 6, p. 1692-1706, 2023. DOI: 10.1107/S1600576723008889

    Abstract: This study characterizes the microstructure and mineralogy of 132 (ODP sample), 1000 and 1880 million-year-old chert samples. By using ultra-smallangle X-ray scattering (USAXS), wide-angle X-ray scattering and other techniques, the preservation of organic matter (OM) in these samples is studied. The scarce microstructural data reported on chert contrast with many studies addressing porosity evolution in other sedimentary rocks. The aim of this work is to solve the distribution of OM and silica in chert by characterizing samples before and after combustion to pinpoint the OM distribution inside the porous silica matrix. The samples are predominantly composed of alpha quartz and show increasing crystallite sizes up to 33 5 nm (1 standard deviation or SD). In older samples, low water abundances (0.03%) suggest progressive dehydration. (U)SAXS data reveal a porous matrix that evolves over geological time, including, from younger to older samples, (1) a decreasing pore volume down to 1%, (2) greater pore sizes hosting OM, (3) decreasing specific surface area values from younger (9.3 0.1 m2 g 1 ) to older samples (0.63 0.07 m2 g 1 , 1 SD) and (4) a lower background intensity correlated to decreasing hydrogen abundances. The pore-volume distributions (PVDs) show that pores ranging from 4 to 100 nm accumulate the greater volume fraction of OM. Raman data show aromatic organic clusters up to 20 nm in older samples. Raman and PVD data suggest that OM is located mostly in mesopores. Observed structural changes, silica–OM interactions and the hydrophobicity of the OM could explain the OM preservation in chert.

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  • IPEN-DOC 29955

    AGODI, C.; CAPPUZZELLO, F.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; AVANZI, L.H.; BELLONE, J.I.; BIJKER, R.; BOZTOSUN, I.; BRASOLIN, S.; BRISCHETTO, G.A.; BURRELLO, S.; BUSSA, M.P.; CALABRESE, S.; CALVO, D.; CAMPAJOLA, L.; CAPIROSSI, V.; CARBONE, D.; CARDOZO, E.N.; CAVALLARO, M.; CHAVEZ LOMELI, E.R.; CHINAGLIA, E.F.; CIRALDO, I.; COLONNA, M.; COSTA, K.M.; DAPO, H.; BENEDICTIS, C. de; GREGORIO, G. de; DELAUNAY, F.; DONALDSON, L.M.; DUMITRACHE, F.; EKE, C.; FERRARESI, C.; FERREIRA, J.L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; GALLIAN, S.; GAMBACURTA, D.; GANDOLFO, E.M.; GARCIA-TECOCOATZI, H.; GARGANO, A.; GIOVANNINI, M.; GUAZZELLI, M.A.; HACISALIHOGLU, A.; HUERTA HERNANDEZ, A.; IAZZI, F.; ISAAK, J.; KHUMALO, T.; KOTILA, J.; KOULOURIS, S.; KUCUK, Y.; LANZALONE, G.; LAVAGNO, A.; LAY, J.A.; LENSKE, H.; LINARES, R.; LUBIAN, J.; MARIN-LAMBARRI, D.J.; MASUNAGA, S.H.; MEDINA, N.H.; MEREU, P.; MORALLES, M. ; NERI, L.; NEVELING, R.; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PANERO, R.; PELLEGRI, L.; PERSIANI, R.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; RUSSO, A.D.; RUSSO, G.; SANTARELLI, T.M.; SANTOPINTO, E.; SANTOS, R.B.B.; SARTIRANA, D.; SGOUROS, O.; SHARMA, V.R.; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VARGAS HERNANDEZ, H.; VILLAGRAN, R.G.; WERNER, V.; YILDIRIM, A.; ZAGATTO, V.A.B.. New high intensity Heavy - Ion beams @ INFN-LNS: NUMEN project status and perspective. Journal of Physics: Conference Series, v. 2586, n. 1, p. 1-5, 2023. DOI: 10.1088/1742-6596/2586/1/012053

    Abstract: The upgrade project POTLNS to produce high-intensity beams has already started at INFN- Laboratori Nazionali del Sud in Catania (Italy). The POTLNS project was triggered by the NUMEN physics case that aims to provide experimental information on the Nuclear Matrix Elements (NMEs) that enter in the expression of the neutrino-less double beta (0νββ) decay halflife. The tools proposed by NUMEN project are the cross-section measurements of nuclear Double Charge Exchange (DCE) reactions. The search for 0νββ decay is currently a key topic in physics, due to its possible wide implications for nuclear physics, particle physics and cosmology: the NUMEN project could provide a crucial contribution in this search.

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  • IPEN-DOC 29953

    ROSALES, THIECLA K.O. ; SILVA, FABIO F.A. da ; BERNARDES, EMERSON S. ; FABI, JOAO P.. Plant-derived polyphenolic compounds: nanodelivery through polysaccharidebased systems to improve the biological properties. Critical Reviews in Food Science and Nutrition, p. 1-25, 2023. DOI: 10.1080/10408398.2023.2245038

    Abstract: Plant-derived polyphenols are naturally occurring compounds widely distributed in plants. They have received greater attention in the food and pharmaceutical industries due to their potential health benefits, reducing the risk of some chronic diseases due to their antioxidant, anti-inflammatory, anticancer, cardioprotective, and neuro-action properties. Polyphenolic compounds orally administered can be used as adjuvants in several treatments but with restricted uses due to chemical instability. The review discusses the different structural compositions of polyphenols and their influence on chemical stability. Despite the potential and wide applications, there is a need to improve the delivery of polyphenolics to target the human intestine without massive chemical modifications. Oral administration of polyphenols is unfeasible due to instability, low bioaccessibility, and limited bioavailability. Nano-delivery systems based on polysaccharides (starch, pectin, chitosan, and cellulose) have been identified as a viable option for oral ingestion, potentiate biological effects, and direct-controlled delivery in specific tissues. The time and dose can be individualized for specific diseases, such as intestinal cancer. This review will address the mechanisms by which polysaccharides-based nanostructured systems can protect against degradation and enhance intestinal permeation, oral bioavailability, and the potential application of polysaccharides as nanocarriers for the controlled and targeted delivery of polyphenolic compounds.

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  • IPEN-DOC 29952

    DOUGLIN, JHON C.; SANKAR, KALIMUTHU V.; BIANCOLLI, ANA L.G. ; SANTIAGO, ELISABETE I. ; TSUR, YOED; DEKEL, DARIO R.. Quantifying the resistive losses of the catalytic layers in anion-exchange membrane fuel cells. ChemSusChem, v. 16, n. 24, p. 1-9, 2023. DOI: 10.1002/cssc.202301080

    Abstract: The existing gap in the ability to quantify the impacts of resistive losses on the performance of anion-exchange membrane fuel cells (AEMFCs) during the lifetime of their operation is a serious concern for the technology. In this paper, we analyzed the ohmic region of an operating AEMFC fed with pure oxygen followed by CO2-free air at various operating currents, using a combination of electrochemical impedance spectroscopy (EIS) and a novel technique called impedance spectroscopy genetic programming (ISGP). Presented here for the first time in this work, we isolated and quantified the individual effective resistance (Reff) values occurring in the AEMFC and their influence on performance as operating conditions change. We believe that this first work is vital to help distinguish the influence of the individual catalytic and mass-transfer processes in this technology thereby providing valuable data to the AEMFC community, with potentially wider applicability to other electrochemical devices where individual physical processes occur simultaneously and need to be sequestered for deeper understanding.

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  • IPEN-DOC 29951

    TESSARI-ZAMPIERI, M.C. ; SANTIAGO, A.F.; LOPES, RENAN N.; COTRIM, MARYCEL E.B. ; SCAPIN, MARCOS A. . A review on the radiological protection materiality in environmental sustainability reports. Brazilian Journal of Radiation Sciences, v. 11, n. 1A, p. 1-11, 2023. DOI: 10.15392/2319-0612.2023.2160

    Abstract: Materiality should be used as a strategic business tool, with implications beyond social, economic, and environmental responsibility in sustainability reporting. Organizations can benefit by incorporate materiality into their existing economic processes, creating a broader approach and ensuring strategies with significant social and environmental topics. This provides stakeholder engagement; prioritizes financial resources for sustainability; develops new business; identifies climate change issues; among others. In this context, aim this study was to present a review the materiality related to radiologic protection in organizational sustainability reports. The results show that radiologic protection is considered in several topics in the organizational sustainability reports evaluated, represented from issues occupational health and safety, environmental assessment suppliers, environmental compliance, local communities, and waste management. It was concluded that, in preparing the materiality matrix, it is necessary to have the methods defined advance to grant them to be reproduced and periodically reviewed. This will allow to demonstrate the sustainability evolution and its alignment with the organizations' strategies.

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  • IPEN-DOC 29950

    PIERETTI, EURICO F. ; CORREA, OLANDIR V. ; NEVES, MAURICIO D.M. das ; ANTUNES, RENATO A.; PILLIS, MARINA F. . Tribology analysis on anodized aluminum surfaces for biomedical purposes. Brazilian Journal of Motor Behavior, v. 17, n. 2, p. 196-197, 2023.

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  • IPEN-DOC 29949

    LOPES, ISABELA S.; SILVA, FLAVIA R. de O. ; COURROL, LILIA C.. Aminolevulinic acid coated—silver, copper, and silver–copper nanoparticles: synthesis, characterization, and application in seed nanopriming. Journal of Plant Growth Regulation, v. 42, n. 9, p. 5842–5854, 2023. DOI: 10.1007/s00344-023-10969-2

    Abstract: Seed priming is a potential tool for improving productivity under diferent environmental conditions. Aminolevulinic acid (ALA) priming can enhance plant tolerance to abiotic stresses, such as salinity, drought, and extreme temperatures. Nanopriming, priming with nanoparticles, can increase seed germination, growth, and plant development. The goal of this work was to compare the germination, growth, and development of sunfower seeds primed at 25 °C for 24 h with fve treatments: water, ALA, silver, copper, and copper-silver nanoparticles (ALANPs) using a two-way analysis of variance. ALANPs were prepared by the photoreduction process (ALA as stabilizing/capping agent) and characterized by UV–Vis, transmission electron microscopy, FTIR, and Zeta potential. The germination percentage, shoot length, root length, seedling vigor index (Vi), and allometric coefcient were obtained on the 3rd, 6th, and 10th days after the priming process. The fuorescence spectra of chlorophyll extract of the whole seedling or directly in the cotyledons were measured. According to the results, seed priming with ALANPs enhanced sunfower seed germination capacity, seed growth, and increased chlorophyll production compared to water and ALA-primed seeds.

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  • IPEN-DOC 29948

    GUIDOLIN, FELIPE R.; GODOI, KEMILY S. de; MEGALE, ANGELA A.A.; SILVA, CRISTIANE C.F. da; KODAMA, ROBERTO T.; CAJADO-CARVALHO, DANIELA; IWAI, LEO K.; SPENCER, PATRICK J. ; PORTARO, FERNANDA C.V.; SILVA, WILMAR D. da. Comparing traditional and toxin-oriented approaches towards antivenom production against Bitis arietans snake venom. Toxins, v. 15, n. 9, p. 1-20, 2023. DOI: 10.3390/toxins15090584

    Abstract: Accidents with snakes are responsible for about 32,000 deaths annually in sub-Saharan Africa, caused mostly by snakes from the genus Bitis, in particular Bitis arietans. B. arietans venom is composed of a complex mixture of toxins, mainly metalloproteases, serine proteases, phospholipases, lectins, and disintegrins. In this work, we compared two approaches to anti-B. arietans antivenom production: immunization with crude snake venom (“traditional approach”) and immunization with selected key toxins isolated from the snake venom (“toxin oriented” approach). Fractions from B. arietans venom were isolated by size exclusion chromatography. Crude venom and samples containing serine proteases or metalloproteases were selected for the immunization of BALB/c mice. Anti-B. arietans and anti-serine proteases plasmas showed a similar recognition profile and higher titers and affinity than the anti-metalloproteases plasma. Cross-recognition of other Bitis venoms was observed, but with low intensity. Although the plasma of all experimental groups inhibited the enzymatic activity of B. arietans venom in vitro, in vivo protection was not achieved. Our results have shown limitations in both approaches considered. Based on this, we proposed a model of polyclonal, species-specific, monovalent antivenoms that could be used as a base to produce customizable polyvalent sera for use in sub-Saharan Africa.

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  • IPEN-DOC 29947

    ANDRADE, L.G.F.; MATTAR NETO, M. ; DONATO, G.H.B.. Crack tunneling effects on the elastic unloading compliance of C(T), SE(B) and clamped SE(T) specimens and correction methodology. Theoretical and Applied Fracture Mechanics, v. 125, p. 1-13, 2023. DOI: 10.1016/j.tafmec.2023.103944

    Abstract: This paper covers the effects of crack tunneling on SE(B), C(T), and clamped SE(T) specimens and presents a correction methodology for this effect and is divided in two parts. Part one presents an investigation of how crack front curvature affects instantaneous crack size predictions based on the elastic unloading compliance technique. Relative crack depths (a/W) of 0.2, 0.5, and 0.7, were considered alongside five levels of crack curvature. Refined finite element models provided load-CMOD records in order to support compliance assessment. The crack front was modeled as a semi-ellipse, and the compliance results agreed with experimental data from the literature. It was shown that for the same equivalent physical straight crack standardized by ASTM, compliance generally decreases as tunneling increases. Since the maximum crack curvature allowed by the aforementioned standards is very restrictive, compliance did not meaningfully change within that limit, however, if violated, this paper shows that higher deviations may occur, leading to inaccurate crack depth estimations and invalid test results. These limits and deviations were clearly determined and, as a step to improve the techniques, this paper also presents – in part two – an exploration of a possible approach to mitigate this problem, which is based on the modification of how the equivalent straight crack of a curved crack front is determined. This new approach presents reduced errors in compliance-based crack size estimation as crack curvature increases when compared to current standardized protocols, and it can support further investigations in order to validate and standardize improved measuring techniques. Finally, it is important to state that even though the ASTM E1820 is used for the determination of crack driving forces, this study is based only on the study of the crack front curvature, the limit imposed by this standard and the deviations on crack size estimation when those limits are violated, while not focusing on determining errors directly on the J-integral. This paper is a further development on the studies published before by the research group.

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  • IPEN-DOC 29946

    NEGAHDARY, MASOUD; VELOSO, WILLIAM B.; BACIL, RAPHAEL P.; BUORO, RAFAEL M.; GUTZ, IVANO G.R.; PAIXAO, THIAGO R.L.C.; LAGO, CLAUDIMIR L. do; SAKATA, SOLANGE K. ; MELONI, GABRIEL N.; FRANCA, MESAQUE C.; OLIVEIRA, THAWAN G. de; AMEKU, WILSON A.; DURAZZO, MICHELANGELO ; ANGNES, LUCIO. Aptasensing of beta-amyloid (Aβ(1− 42)) by a 3D-printed platform integrated with leaf-shaped gold nanodendrites. Sensors and Actuators B: Chemical, v. 393, p. 1-11, 2023. DOI: 10.1016/j.snb.2023.134130

    Abstract: In this study, beta-amyloid (Aβ(1− 42)), an essential biomarker for diagnosing Alzheimer’s disease (AD), was detected via an electrochemical aptasensing platform. Here, an innovative signal transducer was developed using a CO2 laser-ablated 3D-printed electrode modified with leaf-shaped gold nanodendrites (LSG NDs, mean diameter: ~ 92 nm), which could provide an efficient interface for immobilizing aptamer strands. The modified electrode with LSG NDs exhibited an enhancement in its electrochemically active surface area about 7 times, compared with the bare electrode. This modification showed that the size, morphology, and distributions of LSG NDs in amplifying electrochemical signals might effectively provide a highly sensitive infrastructure for analyte detection. The strands of a thiol-functionalized aptamer sequence interacted with the gold surface, which created an optimized biointerface to detect Aβ(1− 42) in a linear range from 0.1 pg mL− 1 to 10 ng mL− 1 (limit of detection (LOD): 84 fg mL− 1 , (S/N = 3)). The developed aptasensor confirmed satisfactory stability, desired reproducibility and regeneration, and minimal impact of interfering agents. In addition, the application of this aptasensor was monitored via an assay of spiked analyte concentrations in 20 samples, including cerebrospinal fluid (CSF) and human serum.

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  • IPEN-DOC 29927

    FERNANDEZ, ANTONIO P.R. ; PERIGO, ELIO A.; FARIA JUNIOR, RUBENS N. de . Modelling and simulation of electrical analogous for permanent magnet materials. Physica Scripta, v. 98, n. 11, p. 1-18, 2023. DOI: 10.1088/1402-4896/ad0079

    Abstract: Expressions to simulate the intrinsic demagnetizing curve of permanent magnets are derived from the classical electrical analogy of a 2RLC circuit as an equivalent to a magnet under demagnetization in a closed magnetic circuit. Comparisons between experimental and theoretical intrinsicMxHcurves were carried out for hard magnetic materials, and the possibility of using this analogous circuit with two components has also been investigated. The demagnetization curves of permanent sintered magnets have been simulated with time domain analytical expressions obtained using an electric equivalent circuit analogous to a closed magnetic circuit. This has been carried out for magnets measured at room temperature and at 373 K. Equivalent electric parameters influenced the various regions of the demagnetization curve. It has also been shown that it was possible to simulate the demagnetization curve of rare earth magnets and also other types of permanent magnets. The Stoner- Wohlfarth model theoretical curves have also been used as a comparison. At last, the electrical analogous parameters have been systematically varied in order to correlate them to the magnetic properties.

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  • IPEN-DOC 29926

    PRADO, FELIPE M. ; FRANCO, TOMÁS J.; WETTER, NIKLAUS U. . Efficient trichromatic Nd:YLF Laser emitting at 1047 nm, 1053 nm and 1314 nm. Photonics, v. 10, n. 10, p. 1-10, 2023. DOI: 10.3390/photonics10101146

    Abstract: We report a Nd:YLF laser, side-pumped by a diode-stack at 797 nm with 1545 W peak power, resulting in triple-wavelength emission at 1314 nm, 1053 nm, and 1047 nm. The resonator is capable of emitting each wavelength separately as well as any combination of them simply by cavity alignment. When operating at 1314 nm, the laser reached record optical-to-optical efficiency of 49%, with a slope efficiency of 53%.

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  • IPEN-DOC 29925

    JUVINO, AMANDA C. ; ZANINI, NATHALIA A. ; AVELINO, SABRINA G. ; OLIVEIRA, YASMIN R.F. de ; GERMANO, GLEICE C.M. ; EDUARDO, CARLOS de P.; ZEZELL, DENISE M. . Caries preventive action of Nd:YAG and fluoride in three different pH conditions: FTIR Spectroscopy and SEM evaluation. Photonics, v. 10, n. 9, p. 1-12, 2023. DOI: 10.3390/photonics10090985

    Abstract: This in vitro study aimed to evaluate the preventive action of topical fluoride application combined with laser irradiation under different pH conditions using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning ElectronMicroscopy (SEM). A total of 180 samples of human dental enamel were prepared and divided into groups: Negative Control, Fluoride (FFA 12.300 F􀀀/g), Laser (Nd:YAG 84.9 J/cm2), and Laser + Fluoride (Nd:YAG 84.9 J/cm2 + FFA 12.300 F􀀀/g). The pH cycling was performed at three different pH conditions: pH 5 (below the critical pH for hydroxyapatite), pH 4.5 (below the critical pH in the presence of fluorapatite), and pH 4 (investigating acid resistance of hydroxyapatite and fluorapatite forms with laser irradiation). In the FTIR analysis, the Laser + Fluoride group demonstrated statistically significant differences compared to the Negative Control group and Fluoride group at pH 4.5 and pH 4 when evaluating the phosphate bands. Similar results were observed in the SEM analysis, where the Laser + Fluoride group exhibited lower demineralization compared to the other treatments at pH 4.5 and pH 4. In conclusion, the Laser + Fluoride group demonstrated a significant reduction in demineralization even at pH levels below the critical threshold for fluorapatite, highlighting its superior acid resistance compared to fluoride alone.

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  • IPEN-DOC 29924

    CABRAL, FERNANDA V. ; SANTANA, BIANCA de M.; LANGE, CAMILA N.; BATISTA, BRUNO L.; SEABRA, AMEDEA B.; RIBEIRO, MARTHA S . Pluronic F-127 hydrogels containing copper oxide nanoparticles and a nitric oxide donor to treat skin cancer. Pharmaceutics, v. 15, n. 1971, p. 1-19, 2023. DOI: 10.3390/ pharmaceutics15071971

    Abstract: Melanoma is a serious and aggressive type of skin cancer with growing incidence, and it is the leading cause of death among those affected by this disease. Although surgical resection has been employed as a first-line treatment for the early stages of the tumor, noninvasive topical treatments might represent an alternative option. However, they can be irritating to the skin and result in undesirable side effects. In this context, the potential of topical polymeric hydrogels has been investigated for biomedical applications to overcome current limitations. Due to their biocompatible properties, hydrogels have been considered ideal candidates to improve local therapy and promote wound repair. Moreover, drug combinations incorporated into the polymeric-based matrix have emerged as a promising approach to improve the efficacy of cancer therapy, making them suitable vehicles for drug delivery. In this work, we demonstrate the synthesis and characterization of Pluronic F-127 hydrogels (PL) containing the nitric oxide donor S-nitrosoglutathione (GSNO) and copper oxide nanoparticles (CuO NPs) against melanoma cells. Individually applied NO donor or metallic oxide nanoparticles have been widely explored against various types of cancer with encouraging results. This is the first report to assess the potential and possible underlying mechanisms of action of PL containing both NO donor and CuO NPs toward cancer cells. We found that PL + GSNO + CuO NPs significantly reduced cell viability and greatly increased the levels of reactive oxygen species. In addition, this novel platform had a huge impact on different organelles, thus triggering cell death by inducing nuclear changes, a loss of mitochondrial membrane potential, and lipid peroxidation. Thus, GSNO and CuO NPs incorporated into PL hydrogels might find important applications in the treatment of skin cancer.

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  • IPEN-DOC 29923

    TUSI, MARCELO M.; POLANCO, NATALY S. de O.; VILLALBA, JUAN C.; ANAISSI, FAUZE J.; OLIVEIRA NETO, ALMIR ; SPINACE, ESTEVAM V. . Influência do tempo de síntese nas propriedades de híbridos PtRu/carbono preparados pelo método da carbonização hidrotérmica / Influence of synthesis time in the properties of PtRu/carbon hybrids prepared by hydrothermal carbonization method. Periódico Tchê Química, v. 20, n. 44, p. 1-14, 2023. DOI: 10.52571/PTQ.v20.n44.2023_01_TUSI_pgs_01_14.pdf

    Abstract: Introdução: Eletrocatalizadores PtRu/C apresentam bons resultados para a eletro-oxidação do metanol. A atividade destes eletrocatalisadores é fortemente dependente do método de síntese. Adicionalmente, o uso de carbonos mesoporosos ou nanoestruturados aumentam o desempenho de eletrocatalisadores usados para a eletro-oxidação de álcoois. A carbonização hidrotérmica é uma alternativa para obter diferentes nanoarquiteturas sem envolver condições drásticas. Objetivos: Assim, este trabalho teve como objetivo avaliar a influência do tempo de síntese nas propriedades de híbridos PtRu/Carbono preparados pelo método da carbonização hidrotérmica. Métodos: Híbridos PtRu/Carbono foram preparados por carbonização hidrotérmica em diferentes tempos (6 h e 12 h). A celulose foi a fonte de carbono e agente redutor e H2PtCl6.6H2O e RuCl3.xH2O foram as fontes de metais e catalisadores do processo de carbonização. Os materiais foram tratados a 900 °C e caracterizados por espectroscopia por energia dispersiva de raios-X, termogravimetria, isotermas de B.E.T., difração de raios-X, microscopia eletrônica de transmissão e voltametria cíclica. A eletro-oxidação do metanol foi estudada por cronoamperometria. Resultados: O aumento de 6 para 12 h de síntese, aparentemente, resultou em aumento do tamanho médio de partículas, redução do volume de mesoporos e aumento da área superficial e do volume total de poros. A cronoamperometria da eletro-oxidação do metanol sobre os híbridos PtRu/Carbono indicaram uma maior eletroatividade para o material preparado em 6 h. Discussão: Provavelmente, a maior eletroatividade do material preparado em 6 h está associada ao menor tamanho de partícula, à estrutura de mesoporos e conteúdo de óxidos superficiais. Conclusões: Portanto, é possível afirmar que o tempo de síntese é um importante parâmetro que afeta as propriedades físico-químicas de híbridos metal/carbono obtidos pelo método da carbonização hidrotérmica.

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  • IPEN-DOC 29922

    CAMPOS, ROGERIO C. de ; BELCHIOR JUNIOR, ANTONIO ; SOARES, HUMBERTO V. ; UMBEHAUN, PEDRO E. ; TORRES, WALMIR M. ; ANDRADE, DELVONEI A. de . Análise de temperaturas em um elemento combustível do reator de pesquisas IEA-R1 durante evento de perda lenta de vazão com RELAP / RELAP Temperature analysis of a fuel element in the IEA-R1 research reactor during a slow loss of flow. Peer Review, v. 5, n. 18, p. 245-271, 2023. DOI: 10.53660/866.prw2310

    Abstract: O código RELAP (Reactor Excursion and Leak Analysis Program) é amplamente utilizado para realizar análises de acidentes em reatores nucleares de potência ou de pesquisa. O presente trabalho apresenta uma simulação do transiente de perda lenta de vazão no núcleo do reator a partir de um modelo com RELAP para o reator de pesquisas IEA-R1 contemplando a piscina, o núcleo do reator, toda tubulação e válvulas do circuito primário, o tanque de decaimento, bomba de circulação principal, trocador de calor e tubulação de retorno à piscina. A modelagem proposta conseguiu representar toda a fenomenologia do acidente, ou seja, o comportamento das temperaturas desde o início da perda de vazão, desligamento do reator, seguida da abertura da válvula de circulação natural até a reversão da direção do escoamento no núcleo do reator. A comparação com resultados experimentais mostrou diferenças de temperaturas de 2,3°C para o fluido e de até 4°C para o revestimento.

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  • IPEN-DOC 29921

    PITOMBEIRA, DANIEL R.S.; COSTA, MARIA J.S.; ANTUNES, RENATO A.; FERREIRA, RAPHAEL O.; SILVA, REJANE M.P. ; SANTOS, REGINALDO S.. Crystalline S-doped TiO2 photoanodes from amorphous titanium oxysulfide (TiOxSy) for photo-oxidation reactions. Optical Materials, v. 142, p. 1-10, 2023. DOI: 10.1016/j.optmat.2023.114081

    Abstract: S-doped TiO2 films were prepared by oxidation annealing of amorphous titanium oxysulfide (TiOxSy) at different temperatures. According to the X-ray diffraction patterns, the films calcined at temperatures of 300–600 ◦C showed only anatase phase, while the uncalcined sample was amorphous. The chemical composition of synthesized TiOxSy was estimated by X-ray photoelectron spectroscopy (XPS). High-resolution S 2p spectra showed S􀀀 2 bonds at 163.47 eV for the amorphous sample. The intensity of this signal decreased after heat treatment. Raman spectroscopy indicated an organization of the material structure with heat treatment of the material. Furthermore, optical characterization revealed that sulfur as dopant into the anatase TiO2 structure, shifted light absorption from ultraviolet to the visible region. Photoeletrochemical studies developed under polychromatic irradiation revealed superior photocurrents for samples calcined at 600 ◦C, with n-type behavior, adequate for photo-oxidation reactions.

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  • IPEN-DOC 29920

    BORGES, ROGER; OLIVEIRA, JULIANA S.S.; QUEIROZ, ANTONIA P.; ZAMBANINI, TELMA; HANASHIRO, AKIKO M.; LIMA, NELSON B. ; SCHNEIDER, JOSÉ F.; MARCHI, JULIANA. On the structure of Ag-containing sol-gel bioactive glasses: a surface crystal growth of metallic silver removes its network modifier role in the glass structure. Open Ceramics, v. 16, p. 1-10, 2023. DOI: 10.1016/j.oceram.2023.100449

    Abstract: Ag-containing bioactive glasses (Ag-BG) have been extensively studied as a bactericidal biomaterial, produced mainly by the sol-gel method over the last decades. According to the literature, sol-gel-derived Ag-BG may show metallic or ionic silver species in the glass structure. However, most of these works lack detailed information about how the addition of silver affects the glass network. In this study, we systematically produced sol-gel derived 58S glasses containing different quantities of Ag2O (1, 5, and 10 wt%), yielding glasses with different proportions of silver species (Ag0 or Ag+1). Results from X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) evidenced the progressive formation of silver crystals due to the addition of silver in the glass structure. 29Si and 31P nuclear magnetic resonance and photoelectronic X-ray spectroscopies evidenced a glass depolymerization caused by Ag1+ addition in the glass structure. On the other hand, the presence of silver crystals (Ag0) removes the network modifier role of silver, yielding glasses with higher network connectivity. A possible mechanism to explain the formation of silver crystals was proposed based on surface nucleation and growth. Finally, we suggest understanding Ag1+ or Ag0 formation as a solution to design glasses with tuned bactericidal properties.

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  • IPEN-DOC 29919

    SANTOS, SOFIA N. dos ; WUEST, MELINDA; JANS, HANS-SONKE; WOODFIELD, JENILEE; NARIO, ARIAN P. ; KRYS, DANIEL; DUFOUR, JENNIFER; GLUBRECHT, DARRYL; BERGMAN, CODY; BERNARDES, EMERSON S. ; WUEST, FRANK. Comparison of three 18F-labeled 2-nitroimidazoles for imaging hypoxia in breast cancer xenografts: [18F]FBNA, [18F]FAZA and [18F]FMISO. Nuclear Engineering and Design, v. 124-125, p. 1-14, 2023. DOI: 10.1016/j.nucmedbio.2023.108383

    Abstract: Background: Tumour hypoxia is associated with increased metastasis, invasion, poor therapy response and prognosis. Most PET radiotracers developed and used for clinical hypoxia imaging belong to the 2-nitroimidazole family. Recently we have developed novel 2-nitroimidazole-derived PET radiotracer [18F]FBNA (N-(4-[18F]fluoro- benzyl)-2-(2-nitro-1H-imidazol-1-yl)-acet-amide), an 18F-labeled analogue of antiparasitic drug benznidazole. The present study aimed to analyze its radio-pharmacological properties and systematically compare its PET imaging profiles with [18F]FMISO and [18F]FAZA in preclinical triple-negative (MDA-MB231) and estrogen receptor-positive (MCF-7) breast cancer models. Methods: In vitro cellular uptake experiments were carried out in MDA-MB321 and MCF-7 cells under normoxic and hypoxic conditions. Metabolic stability in vivo was determined in BALB/c mice using radio-TLC analysis. Dynamic PET experiments over 3 h post-injection were performed in MDA-MB231 and MCF-7 tumour-bearing mice. Those PET data were used for kinetic modelling analysis utilizing the reversible two-tissue-compartment model. Autoradiography was carried out in tumour tissue slices and compared to HIF-1α immunohistochemistry. Detailed ex vivo biodistribution was accomplished in BALB/c mice, and this biodistribution data were used for dosimetry calculation. Results: Under hypoxic conditions in vitro cellular uptake was elevated in both cell lines, MCF-7 and MDA-MB231, for all three radiotracers. After intravenous injection, [18F]FBNA formed two radiometabolites, resulting in a final fraction of 65 ± 9 % intact [18F]FBNA after 60 min p.i. After 3 h p.i., [18F]FBNA tumour uptake reached SUV values of 0.78 ± 0.01 in MCF-7 and 0.61 ± 0.04 in MDA-MB231 tumours (both n = 3), representing tumourto- muscle ratios of 2.19 ± 0.04 and 1.98 ± 0.15, respectively. [18F]FMISO resulted in higher tumour uptakes (SUV 1.36 ± 0.04 in MCF-7 and 1.23 ± 0.08 in MDA-MB231 (both n = 4; p < 0.05) than [18F]FAZA (0.66 ± 0.11 in MCF-7 and 0.63 ± 0.14 in MDA-MB231 (both n = 4; n.s.)), representing tumour-to-muscle ratios of 3.24 ± 0.30 and 3.32 ± 0.50 for [18F]FMISO, and 2.92 ± 0.74 and 3.00 ± 0.42 for [18F]FAZA, respectively. While the fraction per time of radiotracer entering the second compartment (k3) was similar within uncertainties for all three radiotracers in MDA-MB231 tumours, it was different in MCF-7 tumours. The ratios k3/(k3 + k2) and K1*k3/(k3 + k2) in MCF-7 tumours were also significantly different, indicating dissimilar fractions of radiotracer bound and trapped intracellularly: K1*k3/(k2 + k3) [18F]FMISO (0.0088 ± 0.001)/min, n = 4; p < 0.001) > [18F]FAZA (0.0052 ± 0.002)/min, n = 4; p < 0.01) > [18F]FBNA (0.003 ± 0.001)/min, n = 3). In contrast, in MDA-MB231 tumours, only K1 was significantly elevated for [18F]FMISO. However, this did not result in significant differences for K1*k3/(k2 + k3) for all three 2-nitroimidazoles in MDA-MB231 tumours. Conclusion: Novel 2-nitroimidazole PET radiotracer [18F]FBNA showed uptake into hypoxic breast cancer cells and tumour tissue presumably associated with elevated HIF1-α expression. Systematic comparison of PET imaging performance with [18F]FMISO and [18F]FAZA in different types of preclinical breast cancer models revealed a similar tumour uptake profile for [18F]FBNA with [18F]FAZA and, despite its higher lipophilicity, still a slightly higher muscle tissue clearance compared to [18F]FMISO.

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  • IPEN-DOC 29918

    CALDAS NETO, A.B.; SILVA, A.T. . Strategies for decommissioning small nuclear reactors in Brazil. Nuclear Engineering and Design, v. 414, p. 1-14, 2023. DOI: 10.1016/j.nucengdes.2023.112608

    Abstract: The process of decommissioning nuclear reactors is a complex activity that involves various technical and administrative stages. Its main objective is to ensure the safety of the site, workers, the general public, and the environment during the execution of decommissioning activities, aiming for the release of the site from regulatory control. In the Brazilian context, it is essential to develop decommissioning strategies, taking into consideration the established technical and regulatory requirements, as well as following the guidelines of the Brazilian Nuclear Policy (BNP). Eight decommissioning strategies were proposed for small reactors, with different objectives and in different scenarios, encompassing 23 decommissioning approaches, divided into 6 groups: 1) decontamination and dismantling (DD); 2) radioactive waste (RW) management; 3) RW storage management; 4) human resources (HR) and knowledge management; 5) cost estimation; and 6) financial fund management. Additionally, 18 factors affecting the selection of these approaches were considered, taking into account particularities of the Brazilian context. A qualitative risk analysis was conducted using risk assessment techniques from the ABNT NBR ISO/IEC 31,010 standard, with a focus on the Multicriteria Decision Analysis (MCDA) technique. This qualitative analysis allowed for the evaluation of the approaches considering the current scenario and the future scenario, which includes possible changes in the BNP currently under discussion in the National Congress. The observations and results obtained in this study will be useful in guiding future efforts related to nuclear reactor decommissioning projects in Brazil. Based on the proposed strategies and considerations of safety, regulation, and governmental policies, it will be possible to plan and execute decommissioning activities more efficiently and safely.

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  • IPEN-DOC 29917

    SANTOS, THIAGO A. dos ; GENEZINI, FREDERICO A. ; STEFANI, GIOVANNI L. de. Optimization of IEA-R1 reactor core parameters using the particle swarm algorithm. Nuclear Engineering and Design, v. 415, p. 1-9, 2023. DOI: 10.1016/j.nucengdes.2023.112713

    Abstract: This work aims on the development of a FORTRAN 90 code to solve the Loading Pattern Optimization Problem (LPOP) in the IEA-R1 research reactor at the Nuclear and Energy Research Institute (IPEN/CNEN-SP) in S˜ao Paulo, Brazil. The code integrates the Particle Swarm Optimization (PSO) method, with the current reactor calculation methodology. The objective function seeks to maximize the effective multiplication factor (keff), minimize the peak power factor (PPF), and achieve the most uniform neutron flux distribution possible. A comparison with the parameters of the reactor’s current configuration, and the code successfully finds solutions meeting the standard problem requirements. The new configuration enhances peak power (6.93%) and variance (9.62%), slightly increases neutron flux (0.48%), and marginally reduces in keff (0.45%). Additionally, it lowers the maximum fuel cladding temperature (0.7%), contributing to reactor safety.

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  • IPEN-DOC 29916

    MOURA, A.J.S.; MATTAR NETO, M. . Evaluation of the influence of the viscous sublayer on the mechanical stability of fuel plates under axial flow conditions. Nuclear Engineering and Design, v. 415, p. 1-12, 2023. DOI: 10.1016/j.nucengdes.2023.112616

    Abstract: The current work aims to investigate the influence of the viscous sublayer on the mechanical stability of fuel element plates under axial flow conditions by means of two-way Fluid Structure Interaction (FSI) numerical simulations. The methodology adopted is that proposed by (Mantec´on, 2019; Mantec´on and Mattar Neto, 2018), who observed a transition from linear to non-linear behavior between the maximum deflection of the plates in their leading edge with the square of the velocity of the cooling fluid in the channel. The speed at which the transition is identified is the critical speed (Vc). In order to verify the influence of the viscous effects, the CFD domain was discretized from its viscous sublayer. As this approach greatly increases the computational cost, where the characteristics of the flow allowed, symmetry boundary conditions were used. In addition to this approach, it was decided to investigate the ability to solve the FSI problem in steady state. The obtained results confirmed that the boundary layer modeling is sufficient to determine the critical velocity. Furthermore, they also suggest that the steady-state approach and the application of symmetry boundary conditions, where possible, can be used in the design of new fuel elements, supporting traditional methods.

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  • IPEN-DOC 29915

    AVELAR, ALAN M.; DINIZ, CAMILA; CAMARGO, FÁBIO de; GIOVEDI, CLAUDIA ; ABE, ALFREDO ; CHERUBINI, MARCO; PETRUZZI, ALESSANDRO; MOURÃO, MARCELO B.. Best estimate plus uncertainty analysis of metal-water reaction transient experiment. Nuclear Engineering and Design, v. 411, p. 1-12, 2023. DOI: 10.1016/j.nucengdes.2023.112414

    Abstract: Uncertainty analysis is applied in the licensing process for nuclear installations to complement best estimate analysis and to verify that the upper bound value is less than the threshold corresponding to the safety parameter of interest. Metal-water reaction is a critical safety phenomenon of water-cooled nuclear reactors at accident conditions, e.g. Loss-Of-Coolant Accidents (LOCA). AISI 348 cladding is able to increase the accident tolerance comparing to Zr-based alloys and differently from other accident tolerant fuel cladding options, there is operational experience of nuclear power plants with stainless steel. In this study, a transient oxidation experiment of AISI 348 by steam was conducted and the major sources of uncertainty were addressed. An evaluation model was developed to calculate the evolution of mass gain during the experiment. Meanwhile, uncertainty propagation of experimental data was performed. The results show that the mass gain predicted by the transient metal-water reaction model lays within the experimental data uncertainty band. Furthermore, the selection of the oxidation kinetics model seems to be important whether the analysis wills to provide conservative results.

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  • IPEN-DOC 29914

    ABE, ALFREDO ; GIOVEDI, CLAUDIA; MELO, CAIO; SILVA, ANTONIO T. e . Assessment of minimum allowable thickness of advanced steel (FeCrAl) cladding for accident tolerant fuel. Nuclear Engineering and Design, v. 415, p. 1-7, 2023. DOI: 10.1016/j.nucengdes.2023.112707

    Abstract: The ferritic iron-chromium-aluminum (FeCrAl) alloy cladding is considered to be the most promising for near-term application in the ATF framework to replace existing zirconium alloy cladding. Although FeCrAl cladding presents several advantages, it is well known that there are at least two main drawbacks, one is the increased thermal neutron absorption cross-section compared to the current Zr-based cladding resulting in a neutronic penalty and another is tritium higher permeation. In the present study, the minimum allowable thickness of cladding is addressed considering neutronic penalty reduction and the mechanical-structural behavior under the LOCA accident condition. The neutronic penalty assessment was performed using the Monte Carlo code and mechanical-structural performance of the FeCrAl cladding using the TRANSURANUS fuel code, which was modified to consider properly the FeCrAl cladding.

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  • IPEN-DOC 29913

    GATTI, LUCIANA V. ; CUNHA, CAMILLA L.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; MESSIAS, CASSIANO G.; ARAI, EGIDIO; DENNING, SCOTT A.; SOLER, LUCIANA S.; ALMEIDA, CLAUDIO; SETZER, ALBERTO; DOMINGUES, LUCAS G. ; BASSO, LUANA S.; MILLER, JOHN B.; GLOOR, MANUEL; CORREIA, CAIO S.C. ; TEJADA, GRACIELA; NEVES, RAIANE A.L.; RAJÃO, RAONI; NUNES, FELIPE; S.FILHO, BRITALDO S.; SCHMITT, JAIR; NOBRE, CARLOS; CORRÊA, SERGIO M.; SANCHES, ALBER H.; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA; VON RANDOW, CELSO; CRISPIM, STEPHANE P.; SILVA, FRANCINE M.; MACHADO, GUILHERME B.M.. Increased Amazon carbon emissions mainly from decline in law enforcement. Nature, v. 621, p. 318-323, 2023. DOI: 10.1038/s41586-023-06390-0

    Abstract: The Amazon forest carbon sink is declining, mainly as a result of land-use and climate change1–4. Here we investigate how changes in law enforcement of environmental protection policies may have affected the Amazonian carbon balance between 2010 and 2018 compared with 2019 and 2020, based on atmospheric CO2 vertical profiles5,6, deforestation7 and fire data8, as well as infraction notices related to illegal deforestation9. We estimate that Amazonia carbon emissions increased from a mean of 0.24 ± 0.08 PgC year−1 in 2010–2018 to 0.44 ± 0.10 PgC year−1 in 2019 and 0.52 ± 0.10 PgC year−1 in 2020 (± uncertainty). The observed increases in deforestation were 82% and 77% (94% accuracy) and burned area were 14% and 42% in 2019 and 2020 compared with the 2010–2018 mean, respectively. We find that the numbers of notifications of infractions against flora decreased by 30% and 54% and fines paid by 74% and 89% in 2019 and 2020, respectively. Carbon losses during 2019–2020 were comparable with those of the record warm El Niño (2015–2016) without an extreme drought event. Statistical tests show that the observed differences between the 2010– 2018 mean and 2019–2020 are unlikely to have arisen by chance. The changes in the carbon budget of Amazonia during 2019–2020 were mainly because of western Amazonia becoming a carbon source. Our results indicate that a decline in law enforcement led to increases in deforestation, biomass burning and forest degradation, which increased carbon emissions and enhanced drying and warming of the Amazon forests.

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  • IPEN-DOC 29945

    SOUTO-OLIVEIRA, CARLOS E.; MARQUES, MARCIA T.A.; NOGUEIRA, THIAGO; LOPES, FABIO J.S. ; MEDEIROS, JOSE A.G. ; MEDEIROS, ILCA M.M.A. ; MOREIRA, GREGORI A. ; DIAS, PEDRO L. da S.; LANDULFO, EDUARDO ; ANDRADE, MARIA de F.. Impact of extreme wildfires from the Brazilian Forests and sugarcane burning on the air quality of the biggest megacity on South America. Science of the Total Environment, v. 888, p. 1-10, 2023. DOI: 10.1016/j.scitotenv.2023.163439

    Abstract: Recently, extreme wildfires have damaged important ecosystems worldwide and have affected urban areas miles away due to long-range transport of smoke plumes. We performed a comprehensive analysis to clarify how smoke plumes from Pantanal and Amazon forests wildfires and sugarcane harvest burning also from interior of the state of São Paulo (ISSP) were transported and injected into the atmosphere of the Metropolitan Area of São Paulo (MASP), where they worsened air quality and increased greenhouse gas (GHG) levels. To classify event days, multiple biomass burning fingerprints as carbon isotopes, Lidar ratio and specific compounds ratios were combined with back trajectories modeling. During smoke plume event days in the MASP fine particulate matter concentrations exceeded the WHO standard (>25 μg m−3 ), at 99 % of the air quality monitoring stations, and peak CO2 excess were 100 % to 1178 % higher than non-event days. We demonstrated how external pollution events such as wildfires pose an additional challenge for cities, regarding public health threats associated to air quality, and reinforces the importance of GHG monitoring networks to track local and remote GHG emissions and sources in urban areas.

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  • IPEN-DOC 29944

    ARAUJO, MARCIO M. de ; REIS, FABRICIO C. ; ROMANO, JAMILE I.S. ; POTENZA, MARCOS R.; ARTHUR, VALTER. Determinação da dose letal imediata de radiação gama para três carunchos do feijão utilizando irradiador multiproposito. Revista Verde, v. 1, n. 3, p. 39-48, 2023. DOI: 10.5281/zenodo.7853435

    Abstract: Este trabalho teve como objetivo determinar a dose letal imediata de radiação gama do Cobalto60 para Acanthocelides obtectus, Zabrotes subfasciatus e Callosobruchus maculatus, utilizando o irradiador Multiproposito do IPEN/CNEN. Os insetos foram mantidos em grãos de feijão das variedades Phaseolus vulgaris e Vigna unguiculata acondicionados em potes plásticos. Foram separados 20 indivíduos adultos com idade de 3 –7 dias, para cada repetição, num total de 5 repetições por tratamento. Foi irradiado com doses crescentes de radiação gama até atingir a mortalidade total dos insetos. A dose de 3,0 kGy foi a estabelecida para o controle imediato dos insetos adultos das espécies estudadas.

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  • IPEN-DOC 29943

    SOUZA, CATARINA da S. ; ZAMBONI, CIBELE B. ; MOURA, LARISSA A.S. ; METAIRON, SABRINA; SILVA, DALTON G.N. da . Uso de mini-espectrômetro de fluorescência de raios X como alternativa para a prática clínica de dialisados / Use of X-ray fluorescence mini-spectrometer as an alternative for clinical practice of dialysates. Revista Remecs, v. 8, n. 14, p. 52-60, 2023. DOI: 10.24281/rremecs2023.8.14.52-60

    Abstract: Neste estudo, o uso de equipamento compacto e portátil, baseado na tecnologia de Fluorescência de Raios X, foi empregado para execução de análises bioquímicas (dosagens de íons) em microamostras de fluidos corpóreos depositadas em papel. Foi realizada a análise simultânea de íons de relevância clínica e nutricional (Ca, Cl, Fe, K, P e S), em sangue total de pacientes com insuficiência renal crônica (IRC) submetidos a tratamento dialítico. Durante a investigação as concentrações obtidas em sangue total levaram a resultados que corroboram com o quadro clínico obtido pelas análises convencionais. Com os dados do presente foi possível elaborar uma discussão sobre a viabilidade de uso deste equipamento para a realização desses exames bioquímicos em Unidades Básicas de Saúde Fluviais (UBSF), gerando melhorias na qualidade de vida de populações ribeirinhas, bem como no âmbito econômico em função de sua aplicabilidade com menor custo. Descritores: Íons, Sangue, Análise Clínica.

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  • IPEN-DOC 29912

    MAIA, VICTORIA A. ; NANDENHA, JULIO ; GONCALVES, MARLON H. ; SOUZA, RODRIGO F.B. de ; O.NETO, ALMIR . Methane to methanol conversion using proton-exchange membrane fuel cells and PdAu/antimony-doped tin oxide nanomaterials. Methane, v. 2, n. 3, p. 252–264, 2023. DOI: 10.3390/methane2030017

    Abstract: This study investigates the use of Au-doped Pd anodic electrocatalysts on ATO support for the conversion of methane to methanol. The study uses cyclic voltammetry, in situ Raman spectra, polarization curves, and FTIR analysis to determine the optimal composition of gold and palladium for enhancing the conversion process. The results demonstrate the potential for utilizing methane as a feedstock for producing sustainable energy sources. The Pd75Au25/ATO electrode exhibited the highest OCP value, and Pd50Au50/ATO had the highest methanol production value at a potential of 0.05 V. Therefore, it can be concluded that an optimal composition of gold and palladium exists to enhance the conversion of methane to methanol. The findings contribute to the development of efficient and sustainable energy sources, highlighting the importance of exploring alternative ways to produce methanol.

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  • IPEN-DOC 29911

    MOREIRA, TATIANA M. ; GENOVA, LUIS A. . Influência da composição e distribuição de tamanho de microesferas de Al2O3/Fe2O3, produzidas por gelificação interna, na adsorção de metais pesados / Influence of composition and size distribution of Al2O3/Fe2O3 microspheres, produced by internal gelation, on the adsorption of heavy metals. Revista Matéria, v. 28, n. 2, p. 1-11, 2023. DOI: 10.1590/1517-7076-RMAT-2023-0004

    Abstract: Os metais pesados são amplamente utilizados em diversos setores industriais, tais como, metalurgia, mineração, galvanoplastia, têxtil, fertilizantes, baterias, pesticidas, circuito impresso, entre outros, sendo comumente encontrados no efluente gerado por estas indústrias. Por serem extremamente tóxicos, podendo contaminar tanto o ecossistema quanto a comunidade ao seu entorno, se faz necessário um tratamento eficiente dos efluentes, a fim de se reduzir a concentração destes elementos, a níveis aceitáveis, antes do descarte. Dentre os diversos tratamentos de efluentes possíveis, a adsorção é amplamente empregada por sua simplicidade, eficiência e baixo custo. Nesse trabalho, foram produzidas, pelo método de gelificação interna, microesferas porosas contendo alumina e hematita em diferentes concentrações, que foram utilizadas como adsorventes em ensaios de adsorção, em batelada e em coluna de leito fixo, de soluções aquosas contendo Zn2+, Ni2+ e Mn2+. As microesferas foram caracterizadas quanto à morfologia e distribuição de tamanho de partículas, área de superfície específica, adsorção gasosa e fases cristalinas. Foi possível avaliar o efeito da composição e da distribuição de tamanho das microesferas na adsorção dos metais pesados. Obteve-se mais de 90% de adsorção dos metais pesados, no regime de coluna de leito fixo, indicando alta eficiência dessas microesferas como adsorventes destes íons.

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  • IPEN-DOC 29910

    SILVA, P.R.C. ; COLOSIO, M.A. ; ORLANDO, M.T.D.; ROSSI, J.L. . Obtention of hard coating using electrochemical process in aluminum-silicon alloys for automotive vehicles. Materials Research, v. 26, p. 1-7, 2023. DOI: 10.1590/1980-5373-MR-2023-0017

    Abstract: Automotive industry is searching for new ways to improve vehicles’ energy efficiency through mass reduction, using aluminum alloys. This change requires a surface protection to extend the life cycle of the components and aluminum anodization is the most used solution. This research is focused on the intake and exhaust ducts’ surfaces of aluminum internal combustion engines cylinder head, which are subject to chemical agents and temperature variation. To extend the working life of this component it is necessary to obtain a covering protective layer. The process targeted the anodization of an internal surface of a much larger part of a cast aluminum-silicon alloy cylinder head. The anodization was obtained using a H2SO4 solution (184 g.L-1) and a DC voltage starting at 20 V. The Al2O3 layer obtained, inside the cylinder head´s ducts, has an average thickness of 120 μm in accordance with the proposal of providing a suitable surface protection.

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  • IPEN-DOC 29909

    MORAIS, NATHANAEL W.S. ; MUCSI, CRISTIANO S. ; FABRIM, ZACARIAS E. ; SCHON, CLAUDIO G.; ROSSI, JESUALDO L. . Microstructural characterization of U-7.5Nb-2.5Zr alloy after ageing and constrained fatigue. Materials Research, v. 26, Suppl.1, p. 1-6, 2023. DOI: 10.1590/1980-5373-MR-2023-0039

    Abstract: U-7.5Nb-2.5Zr cladded in Zircaloy-4 is one of the most studied fuel prototypes. The Nb and Zrare added to the U to stabilize the body-centered cubic (BCC) gamma phase and grant mechanical and swelling resistance. The U-7.5Nb-2.5Zr undergoes the gamma to α′′ phase transformation, generating compressive stresses due to the volume reduction. The α′′ phase also can transform to a combination of α + γ2 phase (equilibrium phases), which are known to be hard and brittle. This work had the objective to test the effect of ageing the gamma to α′′ phase in thermal cycling of a U-7.5Nb-2.5Zr cladded in Zircaloy-4 part. A co-laminated specimen was aged and thermally cycled in a dilatometry experiment. The samples were characterized through X-ray diffraction and metallography. The results show that the gamma to α′′ phase transformations occur at the begin- ning of the initial ageing, followed by stress relief. During the cycling, the sample demonstrated non-equal thermal strains and presented fractures along with the U matrix.

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  • IPEN-DOC 29908

    FUJIMOTO, T.G. ; SERIACOPI, V.; FERREIRA, L.A.S. ; MACHADO, I.F.; MUCCILLO, E.N.S. . Mechanical and electrical characterization of 8YSZ-ScCeSZ ceramics. Materials Research, v. 26, Suppl.1, p. 1-5, 2023. DOI: 10.1590/1980-5373-MR-2022-0595

    Abstract: The effects of small amounts (up to 5 wt.%) of scandia- and ceria-stabilized zirconia on the electrical conductivity, and the elastic modulus and hardness of yttria-stabilized zirconia were investigated by impedance spectroscopy and nanoindentation tests, respectively. The main purpose of this work was to obtain solid electrolyte compounds with improved properties compared to those of the base materials. Solid electrolytes compounds were prepared by solid-state reaction synthesis with sintering at 1450 ºC for 4 h. All prepared compounds exhibit a cubic fluorite-type structure. The microstructure of the compounds consists of polygonal grains with low (< 2%) porosity. The mean grain size estimated by the intercept method was 5 ± 1 μm. The electrical conductivity of the compound ceramics is lower than that of the base material. Addition of scandia-stabilized zirconia is found to exert a beneficial effect on the matrix by increasing the elastic modulus, achieving 221 MPa for 5 wt.% of the additive.

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  • IPEN-DOC 29907

    ALMEIDA, GISELE F.C.; ARBEX, ALEXANDRA A.; OLIVEIRA, HAMON V.S.; DOMINGUES, NILTON I.; VATAVUK, JAN; REIS, DANIELI A.P.; MASSI, MARCOS; COUTO, ANTONIO A. . Influence of thermal oxidation on the creep behavior of Ti-6Al-4V alloy. Materials Research, v. 26, Suppl.1, p. 1-9, 2023. DOI: 10.1590/1980-5373-MR-2022-0521

    Abstract: The formation of a stable and adherent oxide layer on the Ti-6Al-4V alloy can improve the mechanical and corrosion resistance of this material. This work studied the creep behavior of Ti-6Al-4V alloy after two different thermal oxidation conditions: at 650 °C for 12 h and at 800 °C for 2 h. In the XRD analysis of the oxidized samples, it was possible to observe the formation of rutile (TiO2) and a displacement of the peaks of α and β phases caused by the dissolution of oxygen. In the creep test at 550 °C, the material oxidized at 800 °C for 2 h showed a greater creep life at 125 MPa, the crack took longer to brake probably due to the greater thickness of the layer. At 550°C and 187.5 MPa the material oxidized at 650 °C for 12h has a better creep life, probably due to the layer more adhered.

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  • IPEN-DOC 29906

    OKAMOTO, FABIO; OLIVEIRA, MARA C.L. de; SILVA, ADENILSON A. ; DROPPA JR, ROOSEVELT; ANTUNES, RENATO A.. Effect of anodization on the stress corrosion cracking behavior of the AZ61 magnesium alloy in 0.1 m NaCl solution. Materials Research, v. 26, p. 1-16, 2023. DOI: 10.1590/1980-5373-MR-2022-0357

    Abstract: In the present work, the AZ61 alloy, one of the most important commercial structural magnesium alloys, was anodized in three different alkaline electrolytes consisting of 3 M KOH + 0.15 M Na2SiO3 + 0.1 M Na2B4O7.10H2O, 3 M KOH + 0.5 M Na3PO4 and 3 M KOH + 0.50 M Na2SiO3. The treatment was conducted at two different current densities, 20 and 30 mA.cm-2 for 10 minutes. The anodized layers were characterized by scanning electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The corrosion resistance was assessed by potentiodynamic polarization tests. The SCC behavior was studied using slow strain rate tests in 0.1 M NaCl solution at room temperature. Conventional tensile tests were also conducted in air. The susceptibility to SCC was dependent on the morphology of the anodized film. The composition of the electrolyte and the current density of the anodization treatment affected the SCC susceptibility of the AZ61 alloy. The best corrosion resistance and the lowest susceptibility to SCC were obtained for samples anodized in the borate-containing electrolyte at 30 mA.cm-2. The smooth and compact surface morphology of the anodized film obtained in this condition was the main reason for the improved SCC behavior of the AZ61 alloy.

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  • IPEN-DOC 29905

    RIBEIRO, GLEICY de L.X. ; CASTRO, RENATO S. de; SANTOS, ROGERIO G. dos; BUGARIN, ALINE de F.S. ; TERADA, MAYSA; BATALHA, GILMAR F.; COUTO, ANTONIO . Characterization of Ti6Al4V alloy produced by laser-powder bed fusion and surface modification using nanosecond laser. Materials Research, v. 26, Suppl.1, p. 1-5, 2023. DOI: 10.1590/1980-5373-MR-2022-0544

    Abstract: Ti alloys are widely used in severe corrosion environments where corrosion resistance is required, as biomedical industry. Additive manufacturing produces customized and complexes products. Laser texturing is a process of structuring surfaces using laser pulses, that allows the creation of periodic patterns on the surfaces of materials, to modify them, functionally and/or aesthetically, in a precise and direct way, allowing parameterization, versatility and repeatability. Consequently, bringing together metallic additive manufacturing with laser texturing process could be an alternative to obtain parts with functional hydrophilic surfaces, which improves osteointegration and reduces bacteria adhesion. Thus, the aim of this work is to characterize and evaluate the influence of LASER parameters in as-built additive manufactured potential biomedical components. Ti6Al4V specimens were produced by L-PBF, using Ytterbium LASER with maximum power of 500 W, varying the laser power from 61 W to 244 W. The samples were characterized by SEM, Microhardness, and wettability. After that, some specimens were Laser textured using an Ytterbium optical fiber laser, and then evaluated by SEM, wettability, and 3D roughness. It was possible to observe that the surface of all studied samples was flattened after Laser texturing in comparison with as-built condition, due to the melting of the powder particles.

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  • IPEN-DOC 29904

    PEREIRA, LETICIA dos S. ; DONATO, GUSTAVO H.B.; MATTAR NETO, MIGUEL . Assessment of the von Mises stresses and stress triaxiality in notches using modified tensile specimens. Materials Research, v. 26, Suppl.1, p. 1-8, 2023. DOI: 10.1590/1980-5373-MR-2022-0572

    Abstract: Complete understanding of the local stress triaxiality and stress concentration is essential to ensuring structural safety of several structures. A combination of mechanical tests with numerical simulations can be used to obtain this information. One way to study stress triaxiality is by modifying the standard tensile test geometry (ASTM E8) with a notch. Based on previous results from the literature, five notches were chosen: 10, 5, 3, 2, and 1 mm. These geometries were tested, and the results were numerically reproduced using the Abaqus/Explicit 2020 software. The models used were a non-linear model with the Gurson-Tvergaard-Needleman damage model to reproduce the failure. The numerical analyses allowed the assessment of the von Mises stress and stress triaxiality near the notch to compare with the standard smooth specimen. Two instants were considered as crack propagation onset; the instant of the maximum von Mises stress in the element at the center of the specimen, where the failure process begins; and the moment of maximum stress in the true stress x true strain curve. For the von Mises stress analysis, the difference between the curves was small. The stress triaxiality is a better variable to visualize the influences of the notch. When the strain is equal to a 0.07 (instant of the maximum force for the standard specimens), for the smaller notches (1 and 2 mm), there is a region where the effective plastic strain is zero. Consequently, the stress triaxiality is larger in this region than in the center. For the crack propagation onset instant, the plastic strain occurs along the whole transversal section. In this instant, the maximum value of stress triaxiality occurs in the center for all specimens. These results demonstrate that the stress triaxiality changes as the strain increases, i.e., varies with time.

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  • IPEN-DOC 29903

    LARA, J.A.C. ; ABBADE, L. ; MUCSI, C.S. ; NIZES, A.D.C.; ROSSI, J.L. . Study of Patchwelded Blanks Resistance Spot Welding (RSW) Before Hot Stamping with and without Heat Treatment Parameters. Materials Research, v. 26, Suppl.1, p. 1-8, 2023. DOI: 10.1590/1980-5373-MR-2023-0053

    Abstract: In recent years, increasing automotive safety and energy efficiency has become a major concern in the automotive industry. Advanced high-strength steel (AHSS) was chosen for its weight reduction and high mechanical strength for the body in white (BIW). Specifically, it has been used in 22MnB5 steel press hardening type steel (PHS) with patchweld technology, which enables the production of reinforced and structural parts in a single stroke during the hot forming process. This study aimed to evaluate the resistance spot welding parameters for patchweld before hot stamping, considering the minimum and maximum residual stress, while ensuring a welding nugget diameter within the approved range. Microhardness and X-ray diffraction were used to analyze the welding zones for phase identification and residual stress measurements. After five weeks of elapsed time, the spot weld showed cracks that were not seen immediately after welding and were probably due to a high residual stress state.

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  • IPEN-DOC 29902

    MEDINA, MIDILANE S. ; CARVALHO, SABRINA G.M. ; TABUTI, FRANCISCO N. ; MUCCILLO, ELIANA N.S. ; FONSECA, FABIO C. ; MUCCILLO, REGINALDO . W-doped Lanthanum Molybdenum Oxide/Lithium-Sodium-Potassium Carbonate Composite Membranes for Carbon Dioxide Permeation. Materials, v. 16, n. 14, p. 1-14, 2023. DOI: 10.3390/ma16145128

    Abstract: Single-phase tungsten-doped lanthanum molybdenum oxide (La2MoWO9) ceramic powders were synthesized using the complex polymerization technique. Porous ceramic pellets were obtained by thermally removing graphite, which served as a pore former. The porous pellets were then impregnated with molten eutectic lithium-sodium-potassium carbonates. The energy dispersive X-ray analysis and scanning electron microscopy (FEG-SEM) images of the external and fracture surfaces of the La2MoWO9-(Li,Na,K)2CO3 composite dual-phase membrane revealed the percolation of the carbonate mixture through the pores. Electrochemical impedance spectroscopy measurements conducted at temperatures below and above the melting point of the eutectic carbonate composition demonstrated the contributions of oxygen and carbonate ions to the ionic conductivity of the dual membrane. The electrical conductivity of the carbonate ions within the membrane was continuously monitored for over 1300 h with negligible degradation, implying that the membrane could be used for long-term monitoring of CO2 without aging effects. A comparison of FEG-SEM images taken before and after this endurance test suggested minimal fouling, indicating that the membrane could potentially replace similar zirconia- and ceria-based composite membranes.

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  • IPEN-DOC 29942

    MANHANI, KELLY C.; LACERDA, JOAO P.A. de; NAKANO, VIVIANE E.; CRUZ, LUCAS M.S.; COSTA, ALAN R.; BUSTILLOS, JOSE O.W.V. . Técnicas analíticas para o controle de resíduos de agrotóxicos em alimentos cítricos / Analytical techniques for pesticide residues control in citrus foodstuffs. Revista IPT, v. 8, n. 23, p. 61-82, 2023.

    Abstract: O Brasil é o maior produtor mundial de laranja, responsável pela exportação de três quartos de suco de laranja consumidos no mundo. Devido a posição de destaque na cadeia agroindustrial, a segurança alimentar é item fundamental para garantir a sustentabilidade produtiva, qualidade e competitividade de mercado. Dado a sua importância, com o objetivo de avaliar a qualidade dos citros, neste trabalho foram estudados três métodos de extração: “QuEChERS ORIGINAL”, “QuEChERS Acetato MODIFICADO” e extração Líquido-Líquido, com a utilização dos equipamentos GC/ECD e GC/MS para quantificação e confirmação dos analitos. O método QuEChERS está revolucionando o preparo de amostras de matrizes complexas, e neste estudo, foram avaliados a mudança de pH na extração bem como a proporção de amostra e adição de diferentes sais e adsorventes na etapa de limpeza da amostra (Clean Up) para a eficiência da extração dos ingredientes ativos. Parâmetros de qualidade analítica como seletividade/efeito matriz, linearidade, limite de detecção e quantificação foram estabelecidos para cinco agrotóxicos: Trifluralina, Clorotalonil, Clorpirifós, Dicofol e Azoxistrobina. Foram analisadas um total de 26 amostras de laranja Pêra e suco de laranja, coletadas em feiras livres, supermercados, sítios com produção local e restaurantes da cidade de São Paulo, dentre as quais, três amostras de suco analisadas durante o desenvolvimento apresentaram indícios do agrotóxico Dicofol, proibido pela legislação brasileira.

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  • IPEN-DOC 29941

    ROSSI, JESUALDO L. ; FARIA JUNIOR, RUBENS N. de . O IPEN: da metalurgia nuclear ao grafeno. Revista Grafeno, n. 6, p. 21-23, 2023.

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  • IPEN-DOC 29940

    SUSSA, FABIO V. ; FURLAN, MARCOS R.; SILVA, PAULO S.C. . Produção de biomassa e dos óleos voláteis de Melissa officinalis L. (erva-cidreira) em função da adubação e da sazonalidade / Biomass and volatile oil production of Melissa officinalis L. (lemon balm) under different fertilizations and seasonality. Revista Fitos, v. 17, n. 2, p. 200-2017, 2023. DOI: 10.32712/2446-4775.2023.1450

    Abstract: O estudo sobre adubação e a sazonalidade faz-se necessário, pois podem influenciar na produção de biomassa e na qualidade e quantidade dos óleos voláteis produzidos por plantas medicinais. A pesquisa teve como objetivo identificar o manejo agrícola e época no ano apropriados para a colheita com melhor qualidade dos óleos voláteis de Melissa officinalis submetida ao delineamento experimental inteiramente casualizado (DIC), sendo adubações orgânica e convencional, cultivo controle, com e sem adição micronutrientes e colheitas no outono, inverno, primavera e verão. Os óleos voláteis foram extraídos das folhas de erva-cidreira por hidrodestilação e determinados por cromatografia gasosa acoplada ao espectrômetro de massas (GC-MS). A produção de biomassa foi maior no manejo orgânico nas primeiras colheitas (outono e inverno). O rendimento do óleo essencial (0,02%) não foi influenciado pelo manejo agrícola, entretanto apresentou menor rendimento no inverno (0,003%). A adubação convencional favoreceu a produção dos constituintes majoritários neral (33,9–37,5%) e geranial (54,1–59,3%) nas colheitas do outono, da primavera e do verão. Este trabalho contribui para ampliar o conhecimento do cultivo da espécie e para a Política Nacional de Práticas Integrativas e Complementares, voltadas à implementação da Fitoterapia no Sistema Único de Saúde.

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  • IPEN-DOC 29939

    SOARES, CARLOS ; MOURA, ESPERIDIANA; ARENHARDT, VALERIA; DELIZA, EDUARDO E.V.; SAO PEDRO FILHO, FLAVIO de. Biotechnology management in the Amazon and the production of polypropylene / Brazil Nut Shell fiber biocomposite / Manejo biotecnológico na Amazônia e a produção de biocomposto polipropileno/fibra de casca de Castanha-do-Brasil. Revista de Gestao e Secretariado, v. 14, n. 7, p. 10734-10748, 2023. DOI: 10.7769/gesec.v14i7.2424

    Abstract: This study seeks to produce and analyze the characteristics of a polypropylene composite with vegetable fiber derived from Brazil nut shell. The objective is to develop a biocomposite material based on polypropylene fiber from the brazil nut shell, aiming at a lower environmental impact and promoting sustainability in the industrialization process of biodegradable plastic and/or derivatives. Physical and chemical characterization of vegetable fiber derived from Brazil nut shell (1); characterization of PP and composites with brazil nut shell fibers (PP/FC) (2); characterization of PP and PP/FC/RGO hybrid nanocomposites (3).

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  • IPEN-DOC 29938

    FERREIRA, MAURICIO L.; DALMAS, FABRICIO B.; SANTANNA, MARYLY; RODRIGUES, ELAINE A. ; SODRE, MARCELO G.. Sustainable development in São Paulo's Green Belt Biosphere Reserve: between the void of municipal environmental policies and the ecosystem management of the territory / Desenvolvimento sustentável na Reserva da Biosfera do Cinturão Verde de São Paulo: entre o vazio das políticas ambientais municipais e a gestão ecossistêmica do território. Revista de Gestao Ambiental e Sustentabilidade, v. 12, n. 1, p. 1-37, 2023. DOI: 10.5585/2023.22940

    Abstract: Introduction: The Green Belt Biosphere Reserve, with 2.33 million hectares and its internal urban area with 220 thousand hectares, is configured as a water security territory and expresses a direct relationship between urban development and areas that ensure well-being and ecosystem services for 12% of Brazil's population. With seventy-eight municipalities that fully or partially integrate the GBBR, the socioeconomic differences and the different contexts of urbanization and governance reflect on territorial management at the local level and impact the environmental and regional sustainable development agendas. Objective: Based on a survey of environmental policies and correlations between economic and socio-environmental indicators on a municipal scale for the entire study area, this article assesses the level of development of the main environmental public policies and identifies the relationship between these policies and socio-environmental indicators. Originality: Although the Green Belt Biosphere Reserve is an area recognized by the United Nations (UN), the management of its territory depends on municipal actions that comprise it. Little attention has been paid to environmental management, especially in terms of public environmental policies and a broad and ongoing understanding of the conservation of this area. Results: The analysis shows that the different municipalities in the GBBR have different levels of implementation regarding Environmental Agenda. When considering the Municipal Plans for Urban Afforestation, Adaptation to Climate Change, Atlantic Forest and Solid Waste, only Guarujá, Mogi das Cruzes, Santos and São Paulo have these four policies in preparation or completed, while for 33.3% (n=25) of the municipalities, none of these agendas was developed, and a positive correlation was identified between the HDI and the largest number of implemented policies. Contribution: Large and medium-sized cities in the state of Sao Paulo, Brazil, present studies addressing ecological patterns and processes, however, they do not address specific questions on the environmental sector itself, which this paper aimed at providing. Conclusion: As the Green Belt accounts for 72% of the volume of drinking water in all of São Paulo, the disparities between the municipal indicators analyzed reinforce the need to adopt the GBBR as a platform for adequate governance to integrate policies at different scales for sustainable regional development. Systemic efforts are needed, especially at the municipal scale, in order to carry out adequate environmental management of the GBBR territory.

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  • IPEN-DOC 29937

    FERNANDEZ, ANTONIO P.R.; FARIA JUNIOR, RUBENS N. de . Influência da energia térmica nos parâmetros elétricos de supercapacitores de dupla camada elétrica com eletrodos de carbono ativado / Influence of thermal energy on the electrical parameters of electric double layer supercapacitors with activated carbon electrodes. Revista Científica SENAI-SP, v. 1, n. 3, p. 1-23,

    Abstract: Este artigo objetiva reportar os efeitos da influência da energia térmica sobre os três principais parâmetros elétricos de supercapacitores de dupla camada elétrica, o mesmo que supercapacitores eletroquímicos, sendo tais parâmetros elétricos a capacitância fixa (C(DC)), a resistência em série equivalente (ESR(Inst)) e a resistência em paralelo equivalente (EPR(Dep)), tendo como base de estudo cinco supercapacitores de dupla camada elétrica comerciais e idênticos (mesmo fabricante e modelo), cada qual com capacitância nominal de 1 F/5,5 V, produzidos com eletrodos de carbono ativado e eletrólito orgânico, expostos às temperaturas de 25 oC (ambiente), 50 oC, 75 oC, 100 oC e 125 oC por 672 horas.

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  • IPEN-DOC 29936

    MARTINS, THIAGO G. dos S.; FREITAS, ANDERSON Z. de ; MORGADO, ANTONIO M.L.S.; MARTINS, RICARDO V.. Princípios fisicos básicos do exame de tomografia de coerência óptica / Basic physical principles of the optical coherence tomography examination. Revista Brasileira de Ensino de Física, v. 45, p. e20230125-1 - e20230125-8, 2023. DOI: 10.1590/1806-9126-RBEF-2023-0125

    Abstract: Tomografia por coerência óptica (OCT – sigla referente a optical coherence tomography) é um exame de imagem não invasivo, capaz de gerar análises da seção transversal de tecidos biológicos. O exame de OCT gera imagens a partir da luz refletida e retroespalhada pelos materiais, possuindo diversas aplicações em várias áreas da saúde, como na oftalmologia, cardiologia e gastroenterologia por exemplo. O escopo deste texto é apresentar de forma didática os princípios do funcionamento da tomografia obtida através de fontes de luz coerentes.

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  • IPEN-DOC 29935

    DUARTE, LUIS F. de A.; RIBEIRO, RENAN B.; MEDEIROS, TIERRY V. de; SCHEPPIS, WILLIAM R.; GIMILIANI, GIOVANA T. . Are mangroves hotspots of marine litter for surrounding beaches? Hydrodynamic modeling and quali-quantitative analyses of waste in southeastern Brazil. v. 67, p. 1-12, 2023. DOI: 10.1016/j.rsma.2023.103177

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  • IPEN-DOC 29934

    SILVA, CAMILA R. ; PEREIRA, SAULO T. ; SILVA, DANIELA F.T. ; PRETTO, LUCAS R. de ; FREITAS, ANDERSON Z. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. ; RIBEIRO, MARTHA S. . Noninvasive red Laser intervention before radiotherapy of triple-negative breast cancer in a murine model. Radiation Research, v. 200, n. 4, p. 366-373, 2023. DOI: 10.1667/RADE-23-00050.1

    Abstract: In proton beam treatments, the superposition of several weighted Bragg curves with different incident energies is required to homogeneously irradiate a large tumor volume, creating a spread-out Bragg peak (SOBP). This paper confirms on the suitability of two different methods to create SOBPs – Bortfeld/Jette's and MCMC (Monte Carlo calculations and Matrix Computations), using Monte Carlo simulations performed with TOPAS and MCNP6.1. To generate the SOBPs, algorithms were developed for implementation of the two methods, which enabled to find the weights for thirty variations of SOBPs, categorized according to their width and maximum depths. The MCMC method used weight optimization in designing SOBPs to avoid negative values. In contrast, the Bortfeld/Jette's method yielded the SOBPs according to the variation of a power-law parameter ( ) introduced by the range-energy relationship. Optimal values of , from MCNP and TOPAS, were selected in order to retrieve SOBPs with the best smoothness and then related to those obtained from the literature. In comparing both methods and codes, dose homogeneity parameters ( ) were used to examine the SOBP flatness and gamma analyses were employed to assess the dose deposition along its full extension. The results showed that the SOBPs designed using the MCMC method had better values and computational performance for both codes when compared to the Bortfeld/Jette's method. The gamma analyses highlighted significant differences between the entrance doses comparing the two different methods, for SOBPs with intermediate and high depths and small width. This evaluation was not possible with the values alone, which stresses the relevance of a broad analysis to avoid unintended doses in healthy tissues.

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  • IPEN-DOC 29932

    TAKINAMI, PATRICIA Y. I. ; MASTRO, NELIDA L. del ; ASHFAQ, AIYSHA; AL-SHEIKHLY, MOHAMAD. Ionizing radiation synthesis of hydrogel nanoparticles of gelatin and polyethylene glycol at high temperature. Polymers, v. 15, n. 20, p. 1-11, 2023. DOI: 10.3390/polym15204128

    Abstract: Nanohydrogel particles of polyethylene glycol (PEG), gelatin (GEL), and PEG–GEL mixtures (MIXs) were synthesized with a high electron beam and 60Co gamma-ray radiation. The relatively novel technique of Asymmetrical Flow Field Flow Fractionation (AF4 or AFFFF) coupled to a Multi-Angle Laser Light Scattering (MALLS) detector was mainly used to determine the hydrodynamic diameter (Dh) of the radiation-synthesized PEG, GEL, and PEG–GEL nanohydrogel particles. Our approach to achieving nanohydrogel particles is to enhance the intracrosslinking reactions and decrease the intercrosslinking reactions of the C-centered radicals of the PEG and GEL. The intracrosslinking reactions of these free radicals were enhanced via irradiation at temperatures of 77–80 ◦C and using a high dose rate and pulsed irradiation. The shorter average distance between the C-centered free radicals on the backbone of the thermally collapsed PEG and GEL chain, due to the destruction of hydrogen bonds, enhances the intracrosslinking reactions. It was observed that increasing the dose and dose rate decreased the Dh. DLS results lined up with AF4 measurements. This study provides researchers with a clean method to produce GEL–PEG hydrogels without the use of toxic reagents. Particle size can be tuned with dose, dose rate, and temperature as demonstrated in this work. This is ideal for medical applications as the use of ionizing radiation eliminates toxicity concerns and provides simultaneous sterilization of the material.

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  • IPEN-DOC 29931

    SCAGLIUSI, SANDRA R.; CARDOSO, ELISABETH C.L. ; ESPER, FABIO J.; LUGAO, ADEMAR B. ; WIEBECK, HELIO. Study of mechanical properties of inner tubes exposed to gamma radiation. Polimeros, v. 33, n. 2, p. 1-6, 2023. DOI: 10.1590/0104-1428.20220010

    Abstract: Due to the technical evolution of tires, currently most automotive tires do not have an inner tube. However, truck, motorcycle and bicycle tires still use tires with inner tubes, mostly made of synthetic elastomeric material, which guarantees good potential for air restriction or longer periods for tire pressure failure. This work aims to study changes in the mechanical properties of a truck inner tire, after its exposure to gamma rays, to promote the subsequent recycling of the material. The choice of ionizing radiation is due to its ability to modify the structure and properties of materials, in addition to its applicability in recycling/recovering rubber. For the characterization of the samples, doses of 5, 10, 15, 20, 25 and 30 kGy were applied, and after irradiation as a sample, they were tested using the following characterization methods: traction and elongation at break, hardness, thermal aging and elemental analysis. Observed that is a decrease in the values of the mechanical properties of the samples after irradiation, mainly at doses greater than 10 kGy.

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  • IPEN-DOC 29930

    CABRAL, FERNANDA V. ; CERONE, MICHELA; PERSHEYEV, SAYDULLA; LIAN, CHENG; SAMUEL, IFOR D.W.; RIBEIRO, MARTHA S. ; SMITH, TERRY K.. New insights in photodynamic inactivation of Leishmania amazonensis:: A focus on lipidomics and resistance. PLoS ONE, v. 18, n. 9, p. 1-23, 2023. DOI: 10.1371/journal.pone.0289492

    Abstract: The emergence of drug resistance in cutaneous leishmaniasis (CL) has become a major problem over the past decades. The spread of resistant phenotypes has been attributed to the wide misuse of current antileishmanial chemotherapy, which is a serious threat to global health. Photodynamic therapy (PDT) has been shown to be effective against a wide spectrum of drug-resistant pathogens. Due to its multi-target approach and immediate effects, it may be an attractive strategy for treatment of drug-resistant Leishmania species. In this study, we sought to evaluate the activity of PDT in vitro using the photosensitizer 1,9-dimethyl methylene blue (DMMB), against promastigotes of two Leishmania amazonensis strains: the wild-type (WT) and a lab induced miltefosine-resistant (MFR) strain. The underlying mechanisms of DMMB-PDT action upon the parasites was focused on the changes in the lipid metabolism of both strains, which was conducted by a quantitative lipidomics analysis. We also assessed the production of ROS, mitochondrial labeling and lipid droplets accumulation after DMMB-PDT. Our results show that DMMB-PDT produced high levels of ROS, promoting mitochondrial membrane depolarization due to the loss of membrane potential. In addition, both untreated strains revealed some differences in the lipid content, in which MFR parasites showed increased levels of phosphatidylcholine, hence suggesting this could also be related to their mechanism of resistance to miltefosine. Moreover, the oxidative stress and consequent lipid peroxidation led to significant phospholipid alterations, thereby resulting in cellular dysfunction and parasite death. Thus, our results demonstrated that DMMB-mediated PDT is effective to kill L. amazonensis MFR strain and should be further studied as a potential strategy to overcome antileishmanial drug resistance.

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  • IPEN-DOC 29929

    CORDEIRO, LEANDERSON P.; SA, LIDIA V. de; KITAMIKADO, RAFAEL A.; SAPIENZA, MARCELO T.; BONIFACIO, DANIEL A.B. . Optimized Monte Carlo simulations for voxel-based internal dosimetry. Physics in Medicine and Biology, v. 68, n. 11, p. 1-12, 2023. DOI: 0031-9155

    Abstract: Objective. The scientific community has considered internal dosimetry by the Monte Carlo method the gold standard. However, there is a trade-off between simulation processing time and the statistical quality of the results that makes it a challenge to obtain accurate absorbed dose values in some situations, such as dose estimation in organs affected by cross-irradiation or limited computing power. Variance reduction techniques are used to reduce computational processing time without impairing the statistical quality of the results, such as tracking energy cutoff, secondary particle production threshold, and parallelism of different types of emissions from radionuclides. Approach.In this work, GATE Monte Carlo code and its variance reduction techniques were evaluated to calculate S values of organs from the international commission on radiological protection (ICRP)report 110 male phantom for the lutetium-177, iodine-131, yttrium-90, and radium-223 radionuclides. The results are compared with the data from the OpenDose collaboration. Main results. A cutoff of 5 MeV for local electron deposition and 2.0 mm of secondary particle production range resulted in a computational efficiency increase of 7.9 and 1.05 times, respectively. Simulation of ICRP 107 spectrabased source proved to be about 5 times more efficient when compared to a decay simulation using G4RadioactiveDecay (Geant4-based radioactive decay processes). Track length estimator(TLE) and split exponential track length estimator(seTLE)techniques were used to calculate the absorbed dose of photon emissions, resulting in computational efficiency up to 29.4 and 62.5 times higher when compared to traditional simulations, respectively. In particular, the seTLE technique accelerates the simulation time by up to 1426 times, achieving a statistical uncertainty of 10% in volumes affected by cross-irradiation. Significance. The variance reduction techniques used in this work drastically reduced the simulation time and maintained the statistical quality of the calculated absorbed dose values, proving the feasibility of the use of the Monte Carlo method in internal dosimetry under challenging situations and making it viable for clinical routine or web applications.

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  • IPEN-DOC 29928

    SGOUROS, O.; CUTULI, M.; CAPPUZZELLO, F.; CAVALLARO, M.; CARBONE, D.; AGODI, C.; GREGORIO, G. de; GARGANO, A.; LINARES, R.; BRISCHETTO, G.A.; CALVO, D.; CHAVEZ LOMELI, E.R.; CIRALDO, I.; DELAUNAY, F.; DJAPO, H; EKE, C.; FINOCCHIARO, P.; FISICHELLA, M.; GUAZZELLI, M.A.; HACISALIHOGLU, A.; LUBIAN, J.; MEDINA, N.H.; MORALLES, M. ; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; SOUKERAS, V.; SOULIOTIS, G.; SPATAFORA, A.; TORRESI, D.; YILDIRIM, A.; ZAGATTO, V.A.B.. One-neutron transfer reaction in the 18O + 48Ti collision at 275 MeV. Physical Review C, v. 108, n. 4, p. 044611-1 - 044611-16, 2023. DOI: 10.1103/PhysRevC.108.044611

    Abstract: The present article reports new data on the 48Ti(18O, 17O) 49Ti reaction at 275 MeV incident energy as part of the systematic research pursued within the NUMEN (NUclear Matrix Elements for Neutrinoless double β decay) project. Supplementary measurements of the same reaction on 16O and 27Al targets were also performed in order to estimate the background arising from the use of a composite target (TiO2 + 27Al). These data were analyzed under the same theoretical framework as those obtained with the titanium target in order to reinforce the conclusions of our analysis. Differential cross-section angular distribution measurements for the 17O8+ ejectiles were performed in a wide angular range by using the MAGNEX large acceptance magnetic spectrometer. The experimental results were analyzed within the distorted-wave and coupled-channels Born approximation frameworks. The optical potentials at the entrance and exit channels were calculated in a double folding approach adopting the São Paulo potential, and the spectroscopic amplitudes for the projectile and target overlaps were obtained from large-scale shell model calculations. The differential cross sections are well described by the theoretical calculations, where a weak coupling to collective excitations of projectile and target is inferred. The sensitivity of transfer cross sections on different model spaces adopted in nuclear structure calculations is also discussed.

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  • IPEN-DOC 29901

    ARATA FOUND, ANELYSE ; PRETTO, L.R. de ; USSUI, V. ; LIMA, N.B. de ; SOUZA, G.M. de; MACHADO, J.P.B.; TANGO, R.N.; FREITAS, A.Z. ; LAZAR, D.R.R. . Optical coherence tomography (OCT) for the analysis of zirconia crystalline phase transformation. Materialia, v. 30, p. 1-14, 2023. DOI: 10.1016/j.mtla.2023.101825

    Abstract: This study aimed to validate the Optical coherence tomography (OCT) for the analysis of the transformed zone of two dental zirconia-based materials after hydrothermal ageing and correlate the values with biaxial flexural strength. Kinetics of tetragonal to monoclinic phase transformation (t→m) was calculated. X-ray diffraction (XRD) results showed a sigmoidal transformation rate over time due to the limited X-ray maximum penetration depth. Scanning electron microscope (SEM) and OCT showed a linear relationship between the thickness of the transformed layer and the ageing time. The apparent activation energy was 104.5 kJ/mol and 106.7 kJ/mol (SEM) and 106 kJ/mol and 99.4 kJ/mol (OCT) for the infrastructure and monolithic dental zirconia, respectively. Mechanical strength decreased after 150 h. of ageing at 150 ◦C for both materials showing a correlation with the depth of the transformed zone observed by OCT. Therefore, both monoclinic phase percentage and the depth of the transformed layer are critical concerning zirconia mechanical properties upon hydrothermal ageing. OCT is a non-destructive, fast, innovative, and accurate method for the analysis of zirconia’s t→m phase transformation depth kinetics after hydrothermal ageing.

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  • IPEN-DOC 29900

    SANTOS, SILAS C. dos ; RODRIGUES JR., ORLANDO ; CAMPOS, LETICIA L. . Building up europium thulium co-doped yttria nanoparticles with electron paramagnetic resonance response by colloidal synthesis. Materialia, v. 30, p. 1-13, 2023. DOI: 10.1016/j.mtla.2023.101829

    Abstract: In the radiation dosimetry field the research for new materials is a continuos demand with the aim to provide highly improvement procedures where ionizing radiation is used. Considering this challenge, the present work reports the colloidal synthesis of europium-thulium-co-doped yttria powders (YET) and evaluates the dopants effect on the promotion of EPR response of yttria. The powdered compositions prepared with up to 2at.%Tm and 2at.%Eu (at.%, atomic percentage) were evaluate by XRD, PCS, SEM, and EPR. Based on the results, the proposed synthesis method provided ceramic powders with cubic C-type form and mean particle size (d50) less than 160nm. The most significant EPR dose-response was noticed for the powdered composition prepared with 0.5at. %Tm (YET0.5) as irradiated with 5kGy (60Co). These findings are key parameters to advance toward the formation of new materials for radiation dosimetry.

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  • IPEN-DOC 29899

    TORRECILHA, JEFFERSON K. ; MENDES, ANA P.T. ; THEOPHILO, CAROLINA Y.S. ; LINHARES, HORACIO M. da S.M.D. ; PAULA, JOSE H. de ; SCAPIN, MARCOS A. ; GARCIA, RAFAEL H.L. ; MARAVER, FRANCISCO; SILVA, PAULO S.C. da . Characterization of peloids from different regions of Brazil. Journal of Trace Elements and Minerals, v. 6, p. 1-13, 2023. DOI: 10.1016/j.jtemin.2023.100098

    Abstract: Introduction: Since the early days of humankind, peloids have been used for therapeutic purposes. However, the safety and efficacy of these materials for therapeutic treatments has never been regulated in most of the countries where it is commonly used. Materials and methods: In this study, samples os peloids from different regions of Brazil (´Aguas de S˜ao Pedro, Paraty and Arax´a) were characterized: mineral composition (X-ray diffractometry), physicochemical characteristics (pH, redox potential, moisture, % loss on ignition at 550 ◦C and 1000 ◦C, cooling kinetics, swelling power, specific surface area), concentration of trace elements (X-ray fluorescence, Neutron activation analysis, Graphite furnace atomic absorption spectrometry) and radiological activity (Gamma spectrometry). Results: The results showed great variability in mineral composition, physicochemical characteristics, elemental concentration, concentration of activity and little variation in cooling kinetics. However, this variation is also found when comparing the results with some those presented by other authors. Conclusion: This study concludes that the three peloids studied are good candidates to be used for topical application. Metals and potentially toxic elements present are in concentrations levels that are unlikely to cause risk to health.

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  • IPEN-DOC 29898

    TRICARIO, JULIANA de M. ; FREITAS, GUSTAVO R. ; MUNOZ, BERGMAN N.S.; RODRIGUES, GUILHERME O.; SANTOS, JADE S. dos; SOUZA, CARLA D. de . Educational booklet for patients and health care professionals in the field with focus on ensuring the completeness of radiation therapy treatment. Journal of Radiology Nursing, v. 42, n. 3, p. 346-352, 2023. DOI: 10.1016/j.jradnu.2023.04.001

    Abstract: The present work presented an educational booklet aimed at oncology radiation therapy health professionals focused on treatment completion. The booklet was made in Portuguese and English using the Adobe Illustrator software and are available for free in our own website made on the free platform 123site. The methodology for the booklet was made by literature review and by the experience of 5 professionals. The booklet was submitted to an evaluation at four universities in S~ao Paulo, through a questionnaire applied to students and professors. The results shown that 27.06% confirmed that the booklet have a light visual reading and, in parallel, 80.00% considered the booklet as very informative. 100% judged the booklet is important for professionals working in radiation therapy. Professionals believe they have a responsibility to educate patients (67.06%) and also think they should provide emotional support (76.47%). 98.82% thought that booklets can help the patient complete the treatment. The results obtained were positive in relation to the booklet in their visual part, but even better in the results regarding the content.

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  • IPEN-DOC 29897

    STIPP, WAGNER ; MORAIS, NATHANAEL W.S. ; MARTINS, JOSÉ V.; MATOS, PRISCILA ; ROSSI, JESUALDO L. ; ROSSI, WAGNER de ; RAELLE, MARCUS P. . Surface contaminants’ incorporation after nanosecond laser ablation. Journal of Radioanalytical and Nuclear Chemistry, v. 332, n. 11, p. 4535-4540, 2023. DOI: 10.1007/s10967-023-09153-3

    Abstract: Decontamination and cleaning of surface-contaminated radioactive waste using laser ablation is a promising new technique being researched. One advantage is the potential to recycle waste and reduce the demand for repository storage. However, prior studies have shown that residual radioactivity can persist after laser decontamination indicating the incorporation of contaminants beneath the surface of metal samples. In this study, a q-switched laser was used to measure the depth of the recast zone at various fluences and simulate a decontamination process using a gold-coated sample. The results showed that surface material was found in the recast zone for fluences ranging from 1 to 10 J/cm2. This suggests that incorporation of surface contaminants after laser ablation is an important issue that must be considered before using this technique for radioactive waste treatment.

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  • IPEN-DOC 29896

    ONUDIBIA, MOSES E. ; SILVA, PAULO S.C. da ; ESSIETT, ANIESUA A.; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; IMEH, EDET E.; NNAMANI, NGENE C.; OGODO, ALLOYSIUS C.; MFOM, CELESTIAL B.; OKOH, FRANCA O.. Examination of Natural Radioactivity Concentration and Radiological Exposure of Soil Within Mining Site in Umuahia South Abia State Nigeria, Using High Purity Germanium (HPGe) Gamma Ray Spectrometry. Journal of Radiation and Nuclear Applications, v. 8, n. 3, p. 215-223, 2023. DOI: 10.18576/jrna/080304

    Abstract: Mining activity is one of the major sources of exposure to radiation. The main goal of this study was to determine the natural radioactivity level and its radiological exposure risk in mining site Umuahia South Abia State, Nigeria, using High Purity Germanium (HPGe) gamma ray spectrometry. The activity concentration of 40K, 226Ra and 232Th in the soil ranges from 31±2 to 367±27 Bq kg-1, with mean value of 142±11 Bq kg-1; from 26±2 to 65±5 Bq kg-1, with mean value of 49±4; and from 53±9 to 109±17 Bq kg-1, with mean value of 77±16 Bq kg-1, respectively. The activity concentrations of 226Ra and 232Th are above the global values of 32 and 45 Bq kg-1 while 40K is depleted in relation to the global mean of 412 Bq kg-1. Radiological parameters are generally in agreement with the values observed for other Nigerian and other countries soil reported in literature. The main responsible for the values observed for the radiological parameters is 232Th followed by 226Ra. The use of this soil for dwelling construction is unlikely to pose any radiological harm for the residents.

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  • IPEN-DOC 29893

    CARBONE, D.; AGODI, C.; BELLONE, J.I.; BURRELLO, S.; CALABRESE, S.; CAPPUZZELLO, F.; CAVALLARO, M.; COLONNA, M.; DE GREGORIO, G.; FERREIRA, J.L.; GARGANO, A.; LENSKE, H.; SGOUROS, O.; SPATAFORA, A.; ACOSTA, L.; AMADOR-VALENZUELA, P.; BRISCHETTO, G.A.; CALVO, D.; CAPIROSSI, V.; CHÀVEZ LOMELÌ, E.R.; CIRALDO, I.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; GUAZZELLI, M.A.; HACISALIHOGLU, A.; IAZZI, F.; LAY, J.A.; LINARES, R.; LUBIAN, J.; MEDINA, N.H.; MORALLES, M. ; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; RUSSO, G.; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V.A.B.. The NUMEN project: probing nuclear response to weak interaction by nuclear reactions. Journal of Physics: Conference Series, v. 2586, p. 1-4, 2023. DOI: 10.1088/1742-6596/2586/1/012133

    Abstract: Different reactions channels induced by the 18O + 40Ca collisions at 275 MeV incident energy are simultaneously measured and analysed consistently within the same reaction and structure frameworks within the NUMEN project. The project aims to provide data-driven information for the determination of the nuclear matrix elements involved in the neutrinoless double beta decay. In particular, the elastic and inelastic scattering, one- and two-proton transfer, one-neutron transfer, and single charge exchange reactions are explored. The full quantum-mechanical calculations, performed by including microscopic nuclear structure inputs, describe well all the experimental data, giving support to a multi-channel strategy for the analysis of heavy-ion induced direct reactions.

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  • IPEN-DOC 29892

    COSTA, FERNANDA A.T. da ; PARRA, DUCLERC F. ; CARDOSO, ELISABETH C.L. ; GUVEN, OLGUN. PLA, PBAT, Cellulose Nanocrystals (CNCs), and their blends: biodegradation, compatibilization, and nanoparticle interactions. Journal of Polymers and the Environment, v. 31, n. 11, p. 4662–4690, 2023. DOI: 10.1007/s10924-023-02899-7

    Abstract: PLA/PBAT (Poly (lactic acid)/Poly (butylene adipate-co-terephthalate)) blend is a biodegradable material commonly considered a potential alternative to polymeric products from petroleum sources. PLA is intrinsically brittle, endowed with a low elongation at break and poor impact strength that restricts its use for some applications while PBAT has high ductility, heat resistance, and impact resistance. However, PLA associated with PBAT results in an incompatible blend, due to poor interfacial adhesion. The compatibilization of PLA/PBAT can be improved through physical and chemical interaction between the components, and with exposure to ionizing radiation. Cellulose is the most abundant biodegradable polymer available and is considered the potential material to be used as reinforcement in sustainable composite materials, as well as nanocellulose while an alternative to synthetic nanoparticles. This review describes the state of the art of polymer blends of PBAT and PLA, in terms of manufacturability, compatibilization, biodegradation, radiation processing, and cellulose nanocrystal reinforcement.

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  • IPEN-DOC 29891

    SGOUROS, O.; CAVALLARO, M.; CAPPUZZELLO, F.; CARBONE, D.; AGODI, C.; ALTANA, C.; BRISCHETTO, G.A.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CHAVEZ LOMELI, E.R.; CIRALDO, I.; CUTULI, M.; GREGORIO, G. de; DELAUNAY, F.; DJAPO, H.; EKE, C.; FERREIRA, J.L.; FINOCCHIARO, P.; FISICHELLA, M.; FOTI, A.; GARGANO, A.; GUAZZELLI, M.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.; SOUKERAS, V.; SOULIOTIS, G.; SPATAFORA, A.; TORRESI, D.; YILDIRIM, A.; ZAGATTO, V.A.B.. Recent results on the analysis of the 48Ti(18O,20Ne)46Ca reaction at 275 MeV. Journal of Physics: Conference Series, v. 2586, n. 1, p. 1-5, 2023. DOI: 10.1088/1742-6596/2586/1/012034

    Abstract: The 18O+48Ti reaction was studied at the energy of 275 MeV for the first time under the NUMEN and NURE experimental campaigns with the aim of investigating the complete reaction network potentially involved in the 48Ti→48Ca double charge exchange transition. Understanding the degree of competition between successive nucleon transfer and double charge exchange reactions is crucial for the description of the meson exchange mechanism. Into this context, angular distribution measurements for one- and two-nucleon transfer reactions for the system 18O+48Ti were performed at the MAGNEX facility of INFN-LNS in Catania. An overview of the status of the analysis for the two-proton transfer reaction will be given.

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  • IPEN-DOC 29889

    SPATAFORA, A.; ACOSTA, L.; AGODI, C.; AMADOR-VALENZUELA, P.; BRISCHETTO, G.A.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CHAVEZ-LOMELI, E.R.; CAPPUZZELLO, F.; CARBONE, D.; CAVALLARO, M.; CIRALDO, I.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; HACISALIHOGLU, A.; IAZZI, F.; LINARES, R.; MEDINA, N.; MORALLES, M. ; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; RUSSO, G.; SGOUROS, O.; SILVEIRA, M.A.G. da; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V.A.B.. Experimental and theoretical multi-channel study of direct nuclear reactions: a tool to provide data driven information on the 76Ge neutrino-less double-beta decay. Journal of Physics: Conference Series, v. 2586, n. 1, p. 1-5, 2023. DOI: 10.1088/1742-6596/2586/1/012134

    Abstract: The study of heavy-ions induced double charge-exchange (HI-DCE) nuclear reactions is a promising way to access data-driven information on neutrino-less double-beta decay nuclear matrix elements. In the following, particular attention is given to the (18O,18Ne) and (20Ne,20O) HI-DCE reactions as tools for β +β + and β −β − decays, respectively. The experiments are performed in Catania at the Laboratori Nazionali del Sud of the Istituto Nazionale di Fisica Nucleare (INFN-LNS). The MAGNEX magnetic spectrometer is used to momentum analyse the ejectiles of a large network of nuclear reactions. New preliminary experimental data for the 76Se(18O,18F)76As and 76Ge(20Ne,20F)76As single charge exchange (SCE) and for the 76Se(18O,18Ne)76Ge and 76Ge(20Ne,20O)76Se DCE nuclear reactions were also investigated.

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  • IPEN-DOC 29888

    MARTINS, ROBERTO F.; FRIEHE, KARL; SILVA, CECILIA C.G. e ; LAZAR, DOLORES R.R. ; COUTO, ANTONIO A. ; LIMA, CARLOS R.C.. Study on the attack of molten silicates on Plasma-Sprayed thermal barrier coatings. Journal of Minerals and Materials Characterization and Engineering, v. 11, n. 5, p. 115-130, 2023. DOI: 10.4236/jmmce.2023.115010

    Abstract: Thermal barrier coating (TBC) revolutionized the industry by allowing higher operating temperatures for equipment, such as gas turbines in the aeronautical industry. However, at high temperatures, the TBC is exposed to the attack of molten silicates, known as CMAS (Calcium-Magnesium-Alumino-Silicate), which are particles from the environment that infiltrate the TBC, causing delamination. In this study, samples coated with TBC by thermal spray and covered with CMAS were evaluated at temperatures of 1200˚C and 1250˚C. For each temperature, exposure times of 1 h and 5 h were used. Samples with longer exposure time had a considerable volume increase. The main contribution of this work was to demonstrate the non-wettability of the CMAS, even in the 5-h heat treatments, which prevented its infiltration in the deeper regions. The conditions to guarantee the formation of the silicate and its consequent wettability are also discussed.

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  • IPEN-DOC 29887

    SANTOS, BIANCA P.S. ; BARBOSA, ANDREY S. ; KODAMA, YASKO ; THIAGO, QUEIROZ B. de; SANTIAGO, ELISABETE I. . Tailoring highly stable anion exchange membranes with graft molecular structure ordering using reversible addition-fragmentation chain transfer polymerization for alkaline fuel cells. Journal of Membrane Science, v. 687, p. 1-12, 2023. DOI: 10.1016/j.memsci.2023.122071

    Abstract: The radiation-induced grafting is used to prepare a variety of anion-exchange membranes (AEM) based on poly (ethylene-co-tetrafluoroethylene) (ETFE) utilizing a reversible addition-fragmentation chain transfer (RAFT) agent. The copolymerization process is controlled by the RAFT agent, resulting in AEMs with a restricted molecular weight dispersion. As a result, RAFT-AEMs exhibit decreased water uptake and reduced swelling. A significant improvement in thermal and mechanical characteristics is evidenced, while the conductivity remains practically unaltered. Anion-exchange membrane fuel cell (AEMFC) tests revealed that conventional RIG-AEMs and RAFT-AEMs with low RAFT content (5 wt%) have comparable beginning-of-life performances (~0.95 W cm− 2 ). However, for higher RAFT contents, the performance trends to decrease indicating an imbalance in water management. Furthermore, short-term stability tests suggest that RAFT-AEMs are able to operate highly stable, with a conductivity rate loss of 0.05% h− 1 , which represents an improvement of 160% in comparison to conventional RIG-AEM. AFM analysis demonstrated that structural ordering molecular and morphology tailor the fundamental properties of ETFE-based AEMs, combining enhanced performance and stability for alkaline fuel cell applications.

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  • IPEN-DOC 29886

    PAOLINI, TIAGO B.; ASSUNCAO, ISRAEL P.; COSTA, ISRAEL F.; BLOIS, LUCCA; FELINTO, MARIA C.F.C ; MOURA JUNIOR, RONALDO T.; TEOTONIO, ERCULES E.S.; MALTA, OSCAR L.; CARNEIRO NETO, ALBANO N.; BRITO, HERMI F.. The influence of imidazolium counterions on the luminescence properties of Cnmim[Eu(tta)4] tetrakis complexes in solid-state and ionic liquid solutions. Journal of Luminescence, v. 263, p. 1-11, 2023. DOI: 10.1016/j.jlumin.2023.120158

    Abstract: A series of lanthanide tetrakis complexes Cnmim[Ln(tta)4] where Ln3+: Eu3+ and Gd3+, Cnmim: imidazoliumbased counterions (n from 3 to 8) and tta: thenoyltrifluoroacetonate were synthesized by a one-pot method. The Cnmim[Ln(tta)4] complexes are thermostable up to 210 ◦C and present an isomorphic-like character for the complexes with n = 5, 6, and 7. The phosphorescence spectral profile of the Cnmim[Gd(tta)4] complexes showed intense emission broadbands, in which the barycenters are slightly shifted to energies from the 18,950 to 18,450 cm− 1 range. The Cnmim[Eu(tta)4] complexes in solutions of the corresponding [Cnmim]Br ionic liquids show similar emission spectral profiles as their corresponding in the solid state, indicating that the coordination polyhedron does not undergo a significant variation when the chemical environment is changed. Relatively high values of the intensity parameter Ω2 in both media are presented. The Ω4 values of the complexes in solutions of ionic liquids are also similar, reinforcing that there are small changes in the polyhedral coordination from the solid state to the ionic liquid solution. The series presents high intrinsic emission quantum efficiencies, 90% ≥ QEu Eu ≥ 53%. In addition, theoretical calculations on the intramolecular energy transfer (IET) reveal the participation of the 7 F0→5 D1 and 7 F1→5 G2 transitions for the IET via S1 while the IET via T1 state is dominated by the 7 F0→5 D1 and 7 F1→5 D0 transitions. Therefore, due to their high luminescent features, these Eu3+ tetrakis complexes are potential candidates to be applied as optical markers in the solid-state or even in ionic liquid solutions.

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  • IPEN-DOC 29885

    CASAGRANDE, FERNANDA; FINOTTI, ELISANGELA; SOUZA, RONALD B. de; MOURA, REGIANE; LEONARDO, NOELI F.. Antarctic sea ice concentration in the Brazilian Earth System Model Simulations. Journal of Geoscience and Environment Protection, v. 11, n. 9, p. 1-19, 2023. DOI: 10.4236/gep.2023.119001

    Abstract: Sea ice is an important and complex component of the Earth’s system, acting as both an indicator and an amplifier of climate change. Here, we investigated the ability of the Brazilian Earth System Model (BESM-OA2.5) and four state-of-the-art climate models participating in the fifth phase of the Coupled Model Intercomparison Project, Version 5 (CMIP5) to represent the Antarctic Sea Ice Concentration (SIC) seasonal cycle. We validated the sea ice model’s performance using satellite data from 1980 to 2005 and calculated the skill and RMSE of each model. BESM-OA2.5 results for melt-freeze transitions in the Southern Ocean are consistent with CMIP5 models and satellite data. In February, when the sea ice reaches its annual minimum, the BESM-OA2.5 has the best fit among the models. However, in September, when the Antarctic sea ice reaches its annual maximum, the SIC simulated by BESM-OA2.5 indicated the largest area covered by ice compared to satellite, particularly on the Polar Front. Similar results were found in the CMIP5 models evaluated here. We suggest that the large bias simulated in the Polar Front is related to the inability of the sea ice model to represent the complex ocean- atmosphere-sea ice interactions. The subject is considered a hot topic in climate change studies and lacks conclusive answers.

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  • IPEN-DOC 29884

    SILVA, ABDENEGO R. ; CABRAL, FERNANDA V. ; SILVA, CAMILA R. ; SILVA, DANIELA F.T. ; FREITAS, ANDERSON Z. ; FONTES, ADRIANA; RIBEIRO, MARTHA S. . New insights in phenothiazinium-mediated photodynamic inactivation of candida auris. Journal of Fungi, v. 9, n. 7, p. 1-16, 2023. DOI: 10.3390/jof9070717

    Abstract: n recent years, Candida auris has emerged as a hazardous hospital-acquired pathogen. Its resistance to antifungal treatments makes it challenging, requiring new approaches to manage it effectively. Herein, we aimed to assess the impact of photodynamic inactivation mediated by methylene blue (MB-PDI) or 1,9-dimethyl MB (DMMB-PDI) combined with a red LED against C. auris. To evaluate the photoinactivation of yeasts, we quantified colony-forming units and monitored ROS production. To gain some insights into the differences between MB and DMMB, we assessed lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm). After, we verified the effectiveness of DMMB against biofilms by measuring metabolic activity and biomass, and the structures were analyzed through scanning electron microscopy and optical coherence tomography. We also evaluated the cytotoxicity in mammalian cells. DMMB-PDI successfully eradicated C. auris yeasts at 3 μM regardless of the light dose. In contrast, MB (100 μM) killed cells only when exposed to the highest dose of light. DMMB-PDI promoted higher ROS, LPO and ΔΨm levels than those of MB. Furthermore, DMMB-PDI was able to inhibit biofilm formation and destroy mature biofilms, with no observed toxicity in fibroblasts. We conclude that DMMB-PDI holds great potential to combat the global threat posed by C. auris. © 2023 by the authors.

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  • IPEN-DOC 29883

    DEL MASTRO, NELIDA L. ; GERVASONI, JUANA L.. Women in the nuclear field driving Latin American integration. Journal of Engineering Research, v. 3, n. 35, p. 1-10, 2023. DOI: 10.22533/at.ed.3173352319107

    Abstract: Nuclear energy is used to generate electrical energy, produce radioisotopes, desalinate seawater and produce hydrogen. Nuclear and isotopic techniques contribute to the preservation of water and soil resources and to control pests, ensure food safety and greater food security, as well as improving livestock production and health. The organization of women in the nuclear field (Women in nuclear-WiN) has as one of its functions to make the public aware of the benefits that the application of nuclear energy can bring in all possible applications. This action will help to overcome restrictions from that part of the public that is reticent about using this technology and contribute to Latin American integration. Also, data crossings of the number of related publications are presented, which help to objectively analyze the trend of this integration

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  • IPEN-DOC 29882

    COSTA, ANDREA da; CARVALHO, CAMILA A. de; NASCIMENTO, NANCI do ; ANDRADE JUNIOR, HEITOR F. de. Scavenger receptors mediate increased uptake of irradiated T.gondii extracts by J774 macrophages. International Journal of Radiation Biology, v. 99, n. 10, p. 1559–1569, 2023. DOI: 10.1080/09553002.2023.2187475

    Abstract: Purpose Protein extracts developed increased immunogenicity without the aid of adjuvants after gamma irradiation. Gamma irradiation of snake venom increased antivenin production by detoxification and enhanced immunity, probably due preferential uptake of irradiated venoms by macrophage scavenger receptors. We studied this uptake of irradiated soluble Toxoplasma gondii extract (STag) by the J774 macrophage cell line similar to antigen presenting cells. Material And Methods We labeled STag by biosynthesis in living tachyzoites with radioactive amino acids before purification and irradiation or by adding labels as biotin or fluorescein in stored STag, for quantitative studies or subcellular distribution visualization. Results There was enhanced binding and uptake of irradiated STag into the cells compared to non-irradiated STag. Using fluorescein labeled antigens and morphological assays, we confirmed that cells avidly ingested both native and irradiated proteins but native STag were digested after ingestion while irradiated proteins remained in the cell, suggesting diverse intracytoplasmic pathways. Native or irradiated STag present the same in vitro sensitivity to three types of peptidases. Inhibitors of scavenger receptors (SRs) such as Dextran sulfate (SR-A1 blocker) or Probucol (SR-B blocker) affect the specific uptake of irradiated antigens, suggesting its association with enhanced immunity. Conclusions Our data suggests that cell SRs recognize irradiated proteins, mainly SRs for oxidized proteins, leading to antigen uptake by an intracytoplasmic pathway with fewer peptidases that prolongs presentation to nascent major histocompatibility complex I or II and enhances immunity by better antigen presentation.

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  • IPEN-DOC 29881

    BARROS, JANETTY J.P. ; OLIVEIRA, RENE R. ; LUNA, CARLOS B.B.; WELLEN, RENATE M.R.; MOURA, ESPERIDIANA A.B. . Effectiveness of modified lignin on poly(butylene adipateco-terephthalate)/poly(lactic acid) mulch film performance. Journal of Applied Polymer Science, v. 140, n. 46, p. 1-12, 2023. DOI: 10.1002/app.54684

    Abstract: In this work, the biodegradable poly(butylene adipate-co-terephthalate) (PBAT)/ poly(lactic acid) (PLA) blend (ECOVIO®) and lignin, a renewable and biodegradable natural polymer with high UV absorption and modified by gamma radiation were used to produce agriculture mulch films. Lignin was gammairradiated at 30 and 60 kGy. The irradiated and non-irradiated lignin content of 2 wt% was incorporated into PBAT/PLA blend matrix using a twin-screw extruder and extrusion blown film to prepare flexible films. PBAT/PLA/LIGNIN films were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), tensile tests, contact angle, and UV–Vis analysis. FTIR spectra showed partial miscibility between PBAT/PLA and lignin, being intensified in irradiated lignin compounds. The DSC and XRD results confirmed that the degree of crystallinity of the blends was not significantly influenced by lignin addition. FE-SEM images showed better dispersion and miscibility in PBAT/PLA/Irradiated lignin. Miscibility improvement provided by irradiated lignin promoted better mechanical properties, mainly with lignin irradiated at 60 kGy. PBAT/PLA/LIGNIN films containing 2 wt% showed excellent UV-barrier property and greater hydrophobicity. Summing up, incorporation of low contents of irradiated lignin could be an interesting alternative to produce biodegradable UV-blocking agriculture mulch films.

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  • IPEN-DOC 29880

    FUNGARO, D.A. ; BEROLINI, T.C.R. . Optimization of pelleting parameters for producing composite pellets using zeolitic material from fly ash. Applied Materials and Technology, v. 3, n. 2, p. 13-22, 2023. DOI: 10.31258/Jamt.3.2.13-23

    Abstract: : Zeolitic material in powder form was prepared from y ash by direct activation treatment. e y ash-based zeolite was pelletizing using different inorganic (calcium hydroxide, bentonite, kaolinite) and organic (dextrin) binders with varying percentage. e aim of this study was to produce granular zeolitic material for application in wastewater treatment. e zeolitic materials were analyzed by XRF, XRD, SEM, FTIR, TG-DTG and Nitrogen adsorption/desorption isotherm. Compression and impact tests were used to evaluate the deformation and breakage behaviour of spherical granules. e best performance was obtained by zeolite granular containing 5 wt.% bentonite and 5 wt.% kaolinite with mechanical strength and satisfactory water resistance. e synthesis of pelletized zeolite from by-products derived from coal combustion provides not only environmental and economic benets, but also contributes to achieving the principles of sustainable development.

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  • IPEN-DOC 29879

    MORAES, LETICIA P.R. ; MACHADO, MARINA. ; RODRIGUES, LAYS N. ; SUN, ZIQI; MARANI, DEBORA; FONSECA, FABIO C. . Two-dimensional gadolinium-doped ceria nanosheets for low temperature sintering of solid oxide fuel cells barrier layer. Journal of Alloys and Compounds, v. 967, p. 1-9, 2023. DOI: 0.1016/j.jallcom.2023.171766

    Abstract: A novel method for bottom-up synthesis of two-dimensional (2D) gadolinium-doped cerium oxide (CGO) nanosheets is developed and demonstrated as an efficient precursor for interdiffusion barrier layer deposition in solid oxide fuel cells. The CGO is the standard material used as an interlayer in intermediate-temperature solid oxide fuel cells to avoid undesirable reactions between lanthanum strontium cobalt ferrite (LSCF) cathode and yttria-stabilized zirconia (YSZ) electrolyte materials. Herein, the shape-control of the 2D CGO by a low-cost wetchemical method allowing for the fabrication of fully dense barrier layer of CGO is reported. The high surface coverage promoted by the 2D CGO nanosheets resulted in a thin (~ 1 µm) and dense interdiffusion barrier layer sintered at 1150 ◦C preventing the undesirable reaction between oxide ion conducting phases occurring at higher temperatures. The electrochemical properties of solid oxide fuel cells confirmed the CGO nanosheet as an efficient layer for preventing the formation of resistive phases at the electrolyte/cathode interface.

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  • IPEN-DOC 29878

    SILVA, RICARDO M. e; SOUZA, FERNANDA de L.; DIAS, EDUARDO; SILVA, GELSON T. dos S.T. da; DURAN, FLORYMAR E.; REGO, ARJUN; HIGGINS, DREW; RIBEIRO, CAUE. The role of TiO2:SnO2 heterojunction for partial oxidation of methane by photoelectrocatalytic process at room temperature. Journal of Alloys and Compounds, v. 968, p. 1-7, 2023. DOI: 10.1016/j.jallcom.2023.172090

    Abstract: Partial Oxidation of Methane into hydrocarbons using photoelectrochemical routes is attractive from a sustainability point of view owing to the possibility of using renewable energy (i.e., solar illumination) to activate this stable molecule. However, the process demands the development of novel catalysts that can promote methane activation and oxidation in a controlled manner to increase energy conversion efficiency. Herein, we demonstrated that semiconductor heterostructures improved charge separation compared to the individual materials alone. A more effortless transfer between bands favors the separation of the electron-hole (e− /h+) pairs generated by the photoelectrocatalytic system and prevents them from recombining. This process produces reactive oxygens, essential to driving methane oxidation conversion of the C–H bond cleavage. TiO2:SnO2 semiconductor heterojunction catalysts in film shape were investigated for methane oxidation via a photoelectrocatalytic process. The methane oxidation reactions were carried out in an inflow and sealed electrochemical system for 1 h. Liquid-state nuclear magnetic resonance revealed methanol and acetic acid as the main liquid products, where the TiO2:SnO2 heterojunction exhibited better performance with values of 30 and 8 µmol. cm− 2 .h− 1 , respectively. Compared to their materials alone, the superior performance of the TiO2:SnO2 heterojunction is attributed to the formation of heterostructure type II that enables a more effortless transfer between bands, facilitating the separation of the generated e− /h+ pairs under UV-Vis irradiation. The outcomes achieved here will motivate further studies for developing semiconductor heterojunction structure catalysts in photoelectrocatalysis to partially oxidize methane into valuable chemicals.

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  • IPEN-DOC 29877

    RAPOSO, BRUNO L.; SOUZA, SUEDEN O.; SANTANA, GLEYCIANE S.; LIMA, MAX T.A.; SARMENTO-NETO, JOSE F.; REBOUCAS, JULIO S.; PEREIRA, GORETI; SANTOS, BEATE S.; CABRAL FILHO, PAULO e; RIBEIRO, MARTHA S. ; FONTES, ADRIANA. A novel strategy based on Zn(II) porphyrins and silver nanoparticles to photoinactivate candida albicans. International Journal of Nanomedicine, v. 18, p. 3007-3020, 2023. DOI: 10.2147/IJN.S404422

    Abstract: Background: Photodynamic inactivation (PDI) is an attractive alternative to treat Candida albicans infections, especially considering the spread of resistant strains. The combination of the photophysical advantages of Zn(II) porphyrins (ZnPs) and the plasmonic effect of silver nanoparticles (AgNPs) has the potential to further improve PDI. Here, we propose the novel association of polyvinylpyrrolidone (PVP) coated AgNPs with the cationic ZnPs Zn(II) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin or Zn(II) meso-tetrakis (N-n-hexylpyridinium-2-yl)porphyrin to photoinactivate C. albicans. Methods: AgNPs stabilized with PVP were chosen to allow for (i) overlap between the NP extinction and absorption spectra of ZnPs and (ii) favor AgNPs-ZnPs interaction; prerequisites for exploring the plasmonic effect. Optical and zeta potential (ζ) characterizations were performed, and reactive oxygen species (ROS) generation was also evaluated. Yeasts were incubated with individual ZnPs or their respective AgNPs-ZnPs systems, at various ZnP concentrations and two proportions of AgNPs, then irradiated with a blue LED. Interactions between yeasts and the systems (ZnP alone or AgNPs-ZnPs) were evaluated by fluorescence microscopy. Results: Subtle spectroscopic changes were observed for ZnPs after association with AgNPs, and the ζ analyses confirmed AgNPsZnPs interaction. PDI using ZnP-hexyl (0.8 µM) and ZnP-ethyl (5.0 µM) promoted a 3 and 2 log10 reduction of yeasts, respectively. On the other hand, AgNPs-ZnP-hexyl (0.2 µM) and AgNPs-ZnP-ethyl (0.6 µM) systems led to complete fungal eradication under the same PDI parameters and lower porphyrin concentrations. Increased ROS levels and enhanced interaction of yeasts with AgNPs-ZnPs were observed, when compared with ZnPs alone. Conclusion: We applied a facile synthesis of AgNPs which boosted ZnP efficiency. We hypothesize that the plasmonic effect combined with the greater interaction between cells and AgNPs-ZnPs systems resulted in an efficient and improved fungal inactivation. This study provides insight into the application of AgNPs in PDI and helps diversify our antifungal arsenal, encouraging further developments toward inactivation of resistant Candida spp.

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  • IPEN-DOC 29876

    BIANCOLLI, ANA L.G. ; KONOVALOVA, ANASTASIIA; SANTIAGO, ELISABETE I. ; HOLDCROFT, STEVEN. Measuring the ionic conductivity of solid polymer electrolyte powders. International Journal of Electrochemical Science, v. 18, n. 10, p. 1-10, 2023. DOI: 10.1016/j.ijoes.2023.100288

    Abstract: Ex-situ characterization of solid polymer electrolytes plays an important role in their development as materials for energy applications, with ionic conductivity being a crucial parameter to quantify. Conventional measurements of ionic conductivity often require the formation of a free-standing polymer film which in many instances is difficult to fabricate, thus there may be a need to quantify their ionic conductivity in powder form. In this work, we present a practical and reproducible method for measuring the ionic conductivity of solid polymer electrolytes (SPEs) in their powder form. By using a modified configuration of a through-plane cell, demonstrated with both a proton conducting- and an anion conducting-solid polymer electrolyte powder (SPEP), we are able to obtain ionic conductivity values under variable conditions in order to explore the influence of external parameters on the ionic conductivity of powders. Two types of SPEs in insoluble powder form were employed in this work: (1) a proton-exchange material (SPEP-H+) based on a hyperbranched, sulfo-phenylated poly(phenylene) SPEP (HB-sPPT-H+), with measured ionic conductivity of ⁓ 210 mS cm− 1 at 80 ◦C and 95 % of relative humidity (RH); (2) an anion-exchange conducting polymer in its chloride form (SPEP-Cl- ), consisting of a radiation-grafted ultra-high density polyethylene insoluble SPEP containing covalently-bonded benzyltrimethylammonium (BTMA) head-groups, with measured ionic conductivity of ⁓ 53 mS cm− 1 at 80 ◦C and 95 % RH.

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  • IPEN-DOC 29875

    BERNARDES, ANDRE A.; SILVA, ANDRE L. de; RAMOS, BRUNO; FONSECA, FABIO C. ; GOUVEA, DOUGLAS. Intrinsic defects generated by iodine during TiO2 crystallization and its relationship with electrical conductivity and photoactivity. International Journal of Ceramic Engineering and Science, v. 5, n. 5, p. 1-11, 2023. DOI: 10.1002/ces2.10186

    Abstract: Defect formation during synthesis is one of the strategies used to improve the photoactivity of polycrystalline semiconductors such as titanium dioxide (TiO2). Defects can modify the electronic structure of TiO2 and change the surface of the interaction between the photocatalyst and the reactants. In this study, TiO2 relationship between processing in the presence of iodine and the consequent formation of intrinsic defects were explored. TiO2 nanoparticles were synthesized using the polymeric precursor method and exposed to iodine ions at concentrations up to 5 mol%. After calcination at 350◦C, detailed chemical analyses revealed that iodine was absent in the samples. However, the TiO2 properties, such as specific surface area, crystallite sizes, and specific grain boundary area, were affected. Further experiments, such as electron paramagnetic resonance, diffuse reflectance, optical measurements, and electrochemical impedance spectroscopy indicated the presence of defects in the iodine-processed samples. These defects directly influenced the electrical properties of the material, which affected the photoactivity, measured by the degradation of acetaminophen.

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  • IPEN-DOC 29874

    ALBANIT, LETICIA F.; BEVERARI, ISABELLA; CESAR-RIBEIRO, CAIO; GIMILIANI, GIOVANA T. ; ABESSA, DENIS M. de S.. Toxicity of glitter to marine organisms: a baseline study with embryos of the sand-dollar Mellita quinquiesperforata. International Aquatic Research, v. 15, n. 2, p. 181-189, 2023. DOI: 10.22034/IAR.2023.1973104.1359

    Abstract: This study aimed to determine the toxicity of glitter particles of two colors (green and white) on the embryos of the sand dollar Mellita quinquiesperforata. Toxicity tests were performed using both green- and white-glitter particles. Adult sand dollar individuals were collected and gametes were obtained by osmotic induction. Each glitter was tested in five test solutions: 0.01, 0.1, 1, 10 and 100% (= mg L-1). The results were analyzed by the Wilcoxon–Mann–Whitney test, allowing the determination of the lowest observed effect concentration (LOEC) and the no observed effect concentration (NOEC). The LOECs calculated for the green glitter dispersions were 0.01 % (P < 0.05) in the first two tests, and 100% in the third test. The LOECs for the white-glitter dispersions ranged from 0.01 % to 0.1 %. Our results demonstrate that glitters of both colors are capable of affecting the embryonic development of M. quinquiesperforata.

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  • IPEN-DOC 29873

    GANDOLFO, ELISA M.; OLIVEIRA, JOSE R.B.; CAMPAJOLA, LUIGI; PIERROUTSAKOU, DIMITRA; BOIANO, ALFONSO; AGODI, CLEMENTINA; CAPPUZZUELLO, FRANCESCO; CARBONE, DIANA; CAVALLARO, MANUELA; CIRALDO, IRENE; CALVO, DANIELA; DELAUNAY, FRANCK; EKE, CANEL; LONGHITANO, FABIO; MEDINA, NILBERTO ; MORALLES, MAURICIO ; SARTIRANA, DIEGO; SHARMA, VIJAY R.; SAPATAFORA, ALESSANDRO; TOUFEN, DENNIS; FINOCCHIARO, PAOLO. Response of G-NUMEN LaBr3(Ce) detectors to high counting rates. Instruments, v. 7, n. 3, p. 1-17, 2023. DOI: 10.3390/instruments7030028

    Abstract: The G-NUMEN array is the future gamma spectrometer of the NUMEN experiment (nuclear matrix element for neutrinoless double beta decay), to be installed around the object point of the MAGNEX magnetic spectrometer at the INFN-LNS laboratory. This project aims to explore doublecharge exchange (DCE) reactions in order to obtain crucial information about neutrinoless double beta decay (0νββ). The primary objective of the G-NUMEN array is to detect the gamma rays emitted from the de-excitation of the excited states that are populated via DCE reactions with a good energy resolution and detection efficiency, amidst a background composed of the transitions from competing reaction channels with far higher cross sections. To achieve this, G-NUMEN signals will be processed in coincidence with those generated by the detection of reaction ejectiles by the MAGNEX focal plane detector (FPD). Under the expected experimental conditions, G-NUMEN detectors will operate at high counting rates, of the order of hundreds of kHz per detector, while maintaining excellent energy and timing resolutions. The complete array will consist of over 100 LaBr3 (Ce) scintillators. Initial tests were conducted on the first detectors of the array, allowing for the determination of their performance at high rates.

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  • IPEN-DOC 29872

    LATELLA, RICCARDO; GONZALEZ, ANTONIO J.; BONIFACIO, DANIEL A.B. ; KOVYLINA, MIROSLAVNA; GRIOL, AMADEU; BENLLOCH, JOSE M.; LECOQ, PAUL; KONSTANTINOU, GERGIOS. Exploiting cherenkov radiation with BGO-Based metascintillators. IEEE Transactions on Radiation and Plasma Medical Sciences, v. 7, n. 8, p. 810-818, 2023. DOI: 10.1109/TRPMS.2023.3310581

    Abstract: In time-of-flight positron emission tomography (TOF-PET), the timing capabilities of the scintillation-based detector play an important role. An approach for fast timing is using the so-called metascintillators, which combine two materials leading to the synergistic blending of their favorable characteristics. An added effect for BGO-based metascintillators is taking advantage of better transportation of Cherenkov photons through UV-transparent materials such as plastic (type EJ232). To prove this, we use an optimized Coincidence Time Resolution (CTR) setup based on electronic boards with two output signals (timing and energy) and near-ultraviolet (NUV) and vacuum-ultraviolet (VUV) silicon photomultipliers (SiPMs) from Fondazione Bruno Kessler (FBK), along with different coupling materials. As a reference detector, we employed a 3×3×5 -mm3 LYSO:Ce,Ca crystal pixel coupled with optical grease to an NUV-HD SiPM. The evaluation is based on low-threshold rise time, energy and time of arrival of event datasets. Timing results of a BGO/EJ 2323×3×15 -mm3 metapixel show detector time resolutions (DTRs) of 159 ps for the full photopeak. We demonstrate the possibility of event discrimination using subsets with different DTR from the rise time distributions (RTDs). Finally, we present the synergistic capability of metascintillators to enhance Cherenkov photons detection when used along with VUV-sensitive SiPMs.

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  • IPEN-DOC 29871

    SATO, MARCELO C. ; PIETRO, EMILENE C.I.N.; ALVES, LUCAS M. de C.; KRAMER, AXEL; SANTOS, PAULO S. da S.. Candida auris: a novel emerging nosocomial pathogen – properties, epidemiological situation and infection control / Candida auris: ein neuer gefährlicher nosokomialer Erreger – Eigenschaften, epidemiologische Situation und Prävention. GMS Hygiene and Infection Control, v. 18, p. 1-7, 2023. DOI: 10.3205/dgkh000444

    Abstract: Immunosuppression and critical illnesses in combination with ecological imbalance open the door for novel opportunistic fungal infections, as in case of Candida (C). auris. C. auris has emerged globally as a multidrug-resistant yeast, causing infections and outbreaks in health care facilities. This narrative review discusses the properties of the yeast, the development of the epidemiological situation, the nosocomial spread and causes for nosocomial outbreaks triggered by C. auris in the hospital environment, and summarizes international recommendations for infection control, supplemented by suggestions on diagnostic, screening and antibiotic stewardship.

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  • IPEN-DOC 29870

    PALLOTTA, JUAN V.; CARVALHO, SILVANIA A. de; LOPES, FABIO J. da S. ; CACHEFFO, ALEXANDRE; LANDULFO, EDUARDO ; BARBOSA, HENRIQUE M.J.. Collaborative development of the Lidar Processing Pipeline (LPP) for retrievals of atmospheric aerosols and clouds. Geoscientific Instrumentation Methods and Data Systems, v. 12, n. 2, p. 171-185, 2023. DOI: 10.5194/gi-12-171-2023

    Abstract: Atmospheric lidars can simultaneously measure clouds and aerosols with high temporal and spatial resolution and hence help understand cloud–aerosol interactions, which are the source of major uncertainties in future climate projections. However, atmospheric lidars are typically custom-built, with significant differences between them. In this sense, lidar networks play a crucial role as they coordinate the efforts of different groups, provide guidelines for quality-assured routine measurements and opportunities for side-by-side instrument comparisons, and enforce algorithm validation, all aiming to homogenize the physical retrievals from heterogeneous instruments in a network. Here we provide a high-level overview of the Lidar Processing Pipeline (LPP), an ongoing, collaborative, and open-source coordinated effort in Latin America. The LPP is a collection of tools with the ultimate goal of handling all the steps of a typical analysis of lidar measurements. The modular and configurable framework is generic enough to be applicable to any lidar instrument. The first publicly released version of the LPP produces data files at levels 0 (raw and metadata), 1 (averaging and layer mask), and 2 (aerosol optical properties). We assess the performance of the LPP through quantitative and qualitative analyses of simulated and measured elastic lidar signals. For noiseless synthetic 532 nm elastic signals with a constant lidar ratio (LR), the root mean square error (RMSE) in aerosol extinction within the boundary layer is about 0.1 %. In contrast, retrievals of aerosol backscatter from noisy elastic signals with a variable LR have an RMSE of 11 %, mostly due to assuming a constant LR in the inversion. The application of the LPP for measurements in São Paulo, further constrained by co-located AERONET data, retrieved a lidar ratio of 69.9 ± 5.2 sr at 532 nm, in agreement with reported values for urban aerosols. Over the Amazon, analysis of a 6 km thick multi-layer cirrus found a cloud optical depth of about 0.46, also in agreement with previous studies. From this exercise, we identify the need for new features and discuss a roadmap to guide future development, accommodating the needs of our community.

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  • IPEN-DOC 29869

    PAGLIUSO, DEBORA; PEREIRA, JOAO P. de J.; ULRICH, JOAO C. ; COTRIM, MARYCEL E.B. ; BUCKERIDGE, MARCOS S.; GRANDIS, ADRIANA. Carbon allocation of Spirodela polyrhiza under boron toxicity. Frontiers in Plant Science, v. 14, p. 1-11, 2023. DOI: 10.3389/fpls.2023.1208888

    Abstract: Pectic polysaccharides containing apiose, xylose, and uronic acids are excellent candidates for boron fixation. Duckweeds are the fastest-growing angiosperms that can absorb diverse metals and contaminants from water and have high pectin content in their cell walls. Therefore, these plants can be considered excellent boron (B) accumulators. This work aimed to investigate the relationship between B assimilation capacity with apiose content in the cell wall of Spirodela polyrhiza subjected to different boric acid concentrations. Plants were grown for 7 and 10 days in ½ Schenck-Hildebrandt media supplemented with 0 to 56 mg B.L-1, the non-structural and structural carbohydrates, and related genes were evaluated. The results showed that B altered the morphology and carbohydrate composition of this species during plant development. The optimum B concentration (1.8 mg B.L-1) led to the highest relative growth and biomass accumulation, reduced starch, and high pectin and apiose contents, together with increased expression of UDP-apiose/UDP-xylose synthase (AXS) and 1,4-α-galacturonosyltransferase (GAUT). The toxic state (28 and 56 mg B.L-1) increased the hexose contents in the cell wall with a concomitant reduction of pectins, apiose, and growth. The pectin content of S. polyrhiza was strongly associated with its growth capacity and regulation of B content within the cells, which have AXS as an important regulator. These findings suggest that duckweeds are suitable for B remediation, and their biomass can be used for bioenergy production.

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  • IPEN-DOC 29868

    TEJADA, GRACIELA; GATTI, LUCIANA V. ; BASSO, LUANA S.; CASSOL, HENRIQUE L.G.; SILVA-JUNIOR, CELSO H.L.; MATAVELI, GUILHERME; MARANI, LUCIANO; ARAI, EGIDIO; GLOOR, MANUEL; MILLER, JHON B.; CUNHA, CAMILA L.; DOMINGUES, LUCAS G. ; IPIA, ALBER; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; RANDOW, CELSO V.. CO2 emissions in the Amazon: are bottom-up estimates from land use and cover datasets consistent with top-down estimates based on atmospheric measurements?. Frontiers in Forests and Global Change, v. 6, p. 1-15, 2023. DOI: 10.3389/ffgc.2023.1107580

    Abstract: Amazon forests are the largest forests in the tropics and play a fundamental role for regional and global ecosystem service provision. However, they are under threat primarily from deforestation. Amazonia's carbon balance trend reflects the condition of its forests. There are different approaches to estimate large-scale carbon balances, including top-down (e.g., CO2 atmospheric measurements combined with atmospheric transport information) and bottom-up (e.g., land use and cover change (LUCC) data based on remote sensing methods). It is important to understand their similarities and differences. Here we provide bottom-up LUCC estimates and determine to what extent they are consistent with recent top-down flux estimates during 2010 to 2018 for the Brazilian Amazon. We combine LUCC datasets resulting in annual LUCC maps from 2010 to 2018 with emissions and removals for each LUCC, and compare the resulting CO2 estimates with top-down estimates based on atmospheric measurements. We take into account forest carbon stock maps for estimating loss processes, and carbon uptake of regenerating and mature forests. In the bottom-up approach total CO2 emissions (2010 to 2018), deforestation and degradation are the largest contributing processes accounting for 58% (4.3 PgCO2) and 37% (2.7 PgCO2) respectively. Looking at the total carbon uptake, primary forests play a dominant role accounting for 79% (−5.9 PgCO2) and secondary forest growth for 17% (−1.2 PgCO2). Overall, according to our bottom-up estimates the Brazilian Amazon is a carbon sink until 2014 and a source from 2015 to 2018. In contrast according to the top-down approach the Brazilian Amazon is a source during the entire period. Both approaches estimate largest emissions in 2016. During the period where flux signs are the same (2015–2018) top-down estimates are approximately 3 times larger in 2015–2016 than bottom-up estimates while in 2017–2018 there is closer agreement. There is some agreement between the approaches–notably that the Brazilian Amazon has been a source during 2015–2018 however there are also disagreements. Generally, emissions estimated by the bottom-up approach tend to be lower. Understanding the differences will help improve both approaches and our understanding of the Amazon carbon cycle under human pressure and climate change.

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  • IPEN-DOC 29867

    LIMA, G.C.; CHURA-CHAMBI, R.M.; MORGANTI, L. ; SILVA, V.J.; CABRAL-PICCIN, M.P.; ROCHA, V.; MEDINA, T.S.; RAMOS, R.N.; LUZ, D.. Recombinant human TIM-3 ectodomain expressed in bacteria and recovered from inclusion bodies as a stable and active molecule. Frontiers in Bioengineering and Biotechnology, v. 11, p. 1-11, 2023. DOI: 10.3389/fbioe.2023.1227212

    Abstract: Introduction: Microbial systems, such as Escherichia coli, as host recombinant expression is the most versatile and the cheapest system for protein production, however, several obstacles still remain, such as recovery of soluble and functional proteins from inclusion bodies, elimination of lipopolysaccharides (LPS) contamination, incomplete synthesis, degradation by proteases, and the lack of post-translational modifications, which becomes even more complex when comes to membrane proteins, because they are difficult not only to produce but also to keep in solution in its active state. T-cell Immunoglobulin and Mucin domain 3 (TIM-3) is a type I transmembrane protein that is predominantly expressed on the surface of T lymphocytes, natural killer (NK) cells, dendritic cells, and macrophages, playing a role as a negative immune checkpoint receptor. TIM-3 comprises a single ectodomain for interaction with immune system soluble and cellular components, a transmembrane domain, and a cytoplasmic tail, responsible for the binding of signaling and scaffolding molecules. TIM-3 pathway holds potential as a therapeutic target for immunotherapy against tumors, autoimmunity, chronic virus infections, and various malignancies, however, many aspects of the biology of this receptor are still incompletely understood, especially regarding its ligands. Methods: Here we overcome, for the first time, the challenge of the production of active immune checkpoint protein recovered from bacterial cytoplasmic inclusion bodies, being able to obtain an active, and non-glycosylated TIM-3 ectodomain (TIM-3-ECD), which can be used as a tool to better understand the interactions and roles of this immune checkpoint. The TIM-3 refolding was obtained by the association of high pressure and alkaline pH. Results: The purified TIM-3-ECD showed the correct secondary structure and was recognized from anti-TIM-3 structural-dependent antibodies likewise commercial TIM-3-ECD was produced by a mammal cells system. Furthermore, immunofluorescence showed the ability of TIM-3-ECD to bind to the surface of lung cancer A549 cells and to provide an additional boost for the expression of the lymphocyte activation marker CD69 in anti-CD3/CD28 activated human PBMC. Discussion: Taken together these results validated a methodology able to obtain active checkpoint proteins from bacterial inclusion bodies, which will be helpful to further investigate the interactions of this and others not yet explored immune checkpoints.

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  • IPEN-DOC 29866

    FAUSTINO, MAINARA G. ; MONTEIRO, LUCILENA R. ; LIMA, SAMIA R.M. ; SILVA, TATIANE B. de S.C. da ; PIRANI, DEBORA A. ; PEDREIRA FILHO, WALTER dos R.; GONZAGA, ROBERTA G.; COTRIM, MARYCEL E.B. ; PIRES, MARIA A.F. . Contamination characteristics in runof fractions from a nuclear facility in São Paulo, Brazil. Environmental Monitoring and Assessment, v. 195, n. 11, p. 1-14, 2023. DOI: 10.1007/s10661-023-11886-3

    Abstract: The stormwater runoff may act as a nonpoint pollutant source and contributes to aquatic ecosystem quality decay in urban environments. The aim of this work was to evaluate the runoff characteristics on the transport of total solids and total metals, as well as pH and conductivity responses during the rainfall evolution. During 2017 and 2018, 12 rain events were monitored in 4 sampling stations at a car parking lot located at Nuclear and Energy Research Institute (IPEN/CNEN) in São Paulo/Brazil. A 4-chamber integrated collector allowed the sequential/temporal runoff evolution assessment. The runoff composition, in decreasing order of quantities, was Ca > K > Mg > Si > Al > Fe > Na > Zn > Mn > Sr > Ti > Mo > V > Cu > B > Pb > Ni > Ce > Sb > Cr > La > U > Th > Cd. The amount of total solids, Al, and Fe exceeded the Brazilian water quality standards. Principal component analysis (PCA) identified the elemental clusters linked to the facility activity, soil, and traffic/atmospheric-related deposition. The results show that the runoff characteristics could be differentiated by pollutant source. Factors such as seasonal variation, rain event intensity, air mass from oceanic or continental origin, spatial distribution inside the monitoring area, and the intensity of the first flush must be considered in order to disentangle the elemental clusters and pollution source contributions. In winter, continental air masses were associated with higher concentrations of heavy metals in the surface runoff. Spatial changes with no seasonal variation were observed for U, Th, La, and Ce.

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  • IPEN-DOC 29865

    GOMES, PAULO V.R. ; BONIFACIO, RAFAEL N. ; SILVA, BARBARA P.G. ; FERREIRA, JOAO C. ; SOUZA, RODRIGO F.B. de ; OTUBO, LARISSA ; LAZAR, DOLORES R.R. ; NETO, ALMIR O. . Graphene deposited on glass fiber using a non-thermal plasma system. Eng, v. 4, n. 3, p. 2100–2109, 2023. DOI: 10.3390/eng4030119

    Abstract: This study reports a bottom-up approach for the conversion of cyclohexane into graphene nanoflakes, which were then deposited onto fiberglass using a non-thermal generator. The composite was characterized using transmission electron microscopy, which revealed the formation of stacked few-layer graphene with a partially disordered structure and a d-spacing of 0.358 nm between the layers. X-ray diffraction confirmed the observations from the TEM images. SEM images showed the agglomeration of carbonaceous material onto the fiberglass, which experienced some delamination due to the synthesis method. Raman spectroscopy indicated that the obtained graphene exhibited a predominance of defects in its structure. Additionally, atomic force microscopy (AFM) analyses revealed the formation of graphene layers with varying levels of porosity.

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  • IPEN-DOC 29864

    PEREIRA, NELSON G.A.; GONZALEZ, MARIA E.L.; QUEIROZ, ALVARO A.A. de ; OLIVEIRA, ADHIMAR F.; WANDERLEY NETO, ESTACIO T.. Higher electrical conductivity of functionalized graphene oxide doped with silver and copper (II) ions. Energies, v. 16, n. 20, p. 1-16, 2023. DOI: 10.3390/en16207019

    Abstract: This study presents a new methodology for graphene oxide (GO) synthesis through electrochemical exfoliation of graphite, followed by phthalic anhydride functionalization (PhA-GO) and doping with Cu2+ and Ag+ ions. The synthesis of GO involved the use of an electrochemical cell with H2 SO4 as the electrolyte, with a gradual increase in potential from 2.3 V to 10 V. Extensive characterization techniques confirmed the successful incorporation of oxygen-containing functional groups, verifying the oxidation of graphite. PhA-GO functionalization was confirmed by thermogravimetric analysis, Differential Scanning Calorimetry, Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDX), which confirmed the presence of Cu2+ and Ag+ ions. The Scherrer equation determined a grain size of 75.85 nm for GO. The electrical properties exhibited semiconductor and semimetal behavior, particularly in PhA-GO/Ag+ composites, making them suitable for electronic devices over a wide temperature range, presenting a promising pathway for advanced materials in electronic applications.

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  • IPEN-DOC 29862

    MACHADO, M. ; RODRIGUES, L.N. ; VILELA, V.B. ; FERLAUTO, A.S.; MORAES, T. ; FONSECA, F.C. . Shape-controlled Ni supported GDC catalyst and its application in direct ethanol solid oxide fuel cells. ECS Transactions, v. 111, n. 6, p. 1463-1472, 2023. DOI: 10.1149/11106.1463ecst

    Abstract: Matching catalytic activity with the high temperature heat treatments required to process solid oxide fuel cells (SOFCs) can be a challenge. Shape control is an interesting strategy to stabilize the surface of nanoparticles during heat treatments. In this study, nickelbased catalysts supported on shape-controlled (nanorods and nanocubes) gadolinium-doped cerium oxide (GDC) were evaluated for direct ethanol SOFCs. The morphology of the support had a significant effect on the catalytic activity. It was shown that the Ni catalyst supported on the GDC nanorods maintained high catalytic activity after heat treatments for catalytic layer sintering. Such catalyst was applied as catalytic layer on a SOFC operating directly on anhydrous ethanol at 700 °C. The fuel cell operated for more than 100 h under 0.6 V displaying consistent performance with no indication of degradation from carbon deposition.

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  • IPEN-DOC 29861

    VILELA, V.B. ; THYSSEN, V.V.; FAYARD, F.F.; MASSIM, L.; FLORIO, D.Z. de; FERLAUTO, A.S.; STEIL, M.C.; FONSECA, F.C. . La0.5Ce0.5O1.75-Catalytic layer for methane conversion into C2 products using solid oxide fuel cell. ECS Transactions, v. 111, n. 6, p. 1957-1964, 2023. DOI: 10.1149/11106.1957ecst

    Abstract: Methane (CH4), the major constituent of natural gas and biogas, is an abundant source to obtain value-added hydrocarbons. The oxidative coupling of methane (OCM) is a direct catalytic route to convert CH4 towards C2 hydrocarbons, ethane (C2H6) and ethylene (C2H4). Using a solid oxide fuel cell (SOFC) is a strategy to overcome some challenges of fixed-bed catalytic reactors. In this context, we have studied the La0.5Ce0.5O1.75 (LCO) oxide as a catalytic layer in a SOFC for methane conversion to C2. The activity test was carried out at different O2-/CH4 ratios, varying the anode gas composition, and applied currents.

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  • IPEN-DOC 29860

    MACHADO, MARINA ; BAIUTTI, F.; BERNADET, L.; MORATA, A.; NUNEZ, M.; OUWELTJES, J.P.; FONSECA, F.C. ; TORRELL, M.; TARANCON, A.. Engineered nanofunctional thin films as interfacial layers to enhance performance and durability of SOFCs. ECS Transactions, v. 111, n. 6, p. 1453-1462, 2023. DOI: 10.1149/11106.1453ecst

    Abstract: A strategy to improve the performance and durability of solid oxide fuel cells (SOFCs) is to increase the cathodic activity and decrease the interfacial resistance between the cathode and electrolyte. Pulsed laser deposition (PLD) has been shown to be a promising method to engineer functional interlayers to enhance the cell's performance. In the present study, a bilayer consisting of Sm0.2Ce0.8O2−δ (SDC) barrier layer (BL) and a nanocomposite consisting of SDCLa0.8Sr0.2MnO3−δ (SDC-LSM) employed as a cathode functional layer were deposited by PLD in an anode supported SOFC. The fuel cell showed maximum power density of 0.30 W∙cm−2 at 750 °C. Most importantly, a durability test carried out for 700 h at 750 °C showed a remarkably stable performance of the fuel cell.

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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.