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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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  • IPEN-DOC 29859

    ALMEIDA, MADISON C. de ; BERNARDES, EMERSON S. ; SILVEIRA, MARINA B.; ANDRADE, DELVONEI A. de . O mercado de radiofármacos no Brasil: situação atual e perspectivas / The market for radiopharmaceuticals in Brazil: current situation and prospects. Cuadernos de Educación y Desarrollo, v. 15, n. 8, p. 7928-7947, 2023. DOI: 10.55905/cuadv15n8-059

    Abstract: A Medicina Nuclear é uma especialidade chave, na qual radiofármacos são utilizados para o devido tratamento e acompanhamento de variadas patologias. Estes, processados a partir de insumos importados em sua maioria, implicam em cadeia logística complexa e de escala global. Neste trabalho, tem-se como objetivo apontar as principais questões envolvendo a produção e a distribuição de radiofármacos, bem como perspectivas. Através de pesquisa documental, exploratória, verifica-se o papel do contexto produtivo brasileiro, contemplado em sua maior parte pelo orçamento público, sendo que as meias vidas dos insumos e dos produtos finais são fator de planejamento das aquisições. Situações internacionais, recorrentes, que promovem descontinuidade das cadeias de fornecimento, são alvo de preocupação, levando à busca de soluções. Um panorama através de uma contextualização, o portfólio da Comissão Nacional de Energia Nuclear (CNEN) com suas aplicações, a logística mundial e seus óbices, o Reator Multipropósito Brasileiro, aliados às ações realizadas no orçamento, são seguidos por uma análise de perspectivas, nesta abordagem.

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  • IPEN-DOC 29858

    SANTOS, RAPHAEL A.V. dos; SARKIS, JORGE E. de S. ; ANDRADE, DELVONEI A. de . Fake news oficial: um exemplo do uso da notícia emfalso contexto na sociedade em rede / Official fake news: an example of the use of news in false context innetwork society. Cuadernos de Educación y Desarrollo, v. 15, n. 6, p. 5782-5803, 2023. DOI: 10.55905/cuadv15n6-049

    Abstract: O objetivo deste artigo é analisar a divulgação do índice do PIB brasileiro, divulgado em 2022, como exemplo do que pode se chamar “fake news oficial”, onde a confiabilidade do emissor se sobrepõe ao caráter factível e plausível da informação, necessárias ao fato real. Para isso se baseia nas teorias de Castell, das relações de poder nos processos de comunicação socializada e da desordem da informação.

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  • IPEN-DOC 29857

    ROLIM, WESLEY J.R.; SPENCER, PATRICK J.; ANDRADE, DELVONEI A. de . Development of an arduino based real time environmental monitor for animal facilities / Desenvolvimento de um monitor ambiental em tempo real baseado em arduino para instalações de animais. Cuadernos de Educación y Desarrollo, v. 15, n. 3, p. 2913-2931, 2023. DOI: 10.55905/cuadv15n3-049

    Abstract: Animal facilities are installations of great importance for the advancement of animal research, since it is where the activities of animal breeding, maintenance and experimentation are carried out. Based on this assumption, the present dissertation addresses the development of a monitoring system for environmental factors such as temperature, relative humidity, ammonia and luminosity in an automated way through open source hardware and software aiming at a low cost, accessible prototype that will contribute to guarantee animal welfare, the technical management of the facilities, shared monitoring in real time, decision making in case of irregularities in the observed factors and computerized systemic record. After installing the prototype in the breeding room of the IPEN animal facility, tests were carried out with calibrated detectors in order to validate the readings. Our data confirm the positive correlation obtained, thus validating the adoption of the open source sensor as a tool for monitoring.

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  • IPEN-DOC 29855

    QUEIROZ, FERNANDA M. ; BUGARIN, ALINE de F.S. ; AYUSSO, VICTOR H. ; TERADA, MAYSA; COSTA, ISOLDA . Investigation on the Effect of a Chromium-Free Sealing Treatment for the Corrosion Resistance of AA2198-T851 after Tartaric Sulphuric Anodizing (TSA). Corrosion and Materials Degradation, v. 4, n. 2, p. 331-344, 2023. DOI: 10.3390/cmd4020017

    Abstract: The AA 2198-T851 is a third-generation Al-Li alloy developed for use in the aircraft industry. Al-Li alloys are susceptible to localized corrosion due to their complex microstructure resulting from the used thermomechanical treatment. In order to prevent localized corrosion, these alloys are usually protected by anodizing in order to avoid a corrosive environment. Subsequently, for anodizing, a sealing treatment is usually performed for parts. Some sealing treatments use hexavalent-chromiumion-containing solutions. In this investigation, a chromium-free sealing treatment in a solution with cerium ions has been carried out, and the effect on the corrosion resistance of the AA2198-T851 alloy was investigated. Hydrothermally sealed or unsealed samples were also tested for corrosion resistance for comparison reasons. The corrosion resistance of the anodized aluminum alloy, either hydrothermally sealed or in a cerium-ion-containing solution, was evaluated in a sodium chloride solution by electrochemical impedance spectroscopy as a function of immersion time. The samples sealed in a cerium-containing solution increased their corrosion resistance when compared to the hydrothermally sealed. The effectiveness of the sealing process with cerium that was observed in the electrochemical tests indicated that after the corrosive attack of the barrier layer, there was a “sealing” process of the sample surface.

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  • IPEN-DOC 29854

    CERAVOLO, FLAVIO E. ; ROCHA, MARCELO da S. ; MESQUITA, ROBERTO N. de ; ANDRADE, DELVONEI A. de . CFD Simulation of isothermal upward two-phase flow in a vertical annulus using interfacial area transport equation / Simulação Computacional de fluxo bifásico ascendente isotérmico em um anel vertical usando a equação de transporte de área interfacial. Concilium, v. 23, n. 15, p. 21-48, 2023. DOI: 10.53660/CLM-1617-23I17

    Abstract: This work presents a numerical simulation of a vertical, upward, isothermal two-phase flow of air bubbles and water in an annular channel applying a Computational Fluid Dynamics (CFD) code. For this, the Two-Fluid model is applied considering interfacial force correlations, namely: drag, lift, wall lubrication, turbulent dispersion, and virtual mass. The turbulence k-ε model effects and the influence of One-group Interfacial Area Transport Equation (IATE) are taken into account, in this case, the influence of two source term correlations for the bubble breakup and coalescence IATE is analysed. The work assesses whether the code properly represents the physical phenomenon by comparing the simulation results with experimental data obtained from the literature. Six flow conditions are evaluated based on two superficial liquid velocities and three void fractions in the bubbly flow regimen. The annular channel adopted has an outer pipe with an internal diameter of 38.1 mm and an inner cylinder of 19.1 mm. To represent this geometry, a three-dimensional mesh was generated with 160,000 elements, after a mesh sensitivity study. The void fraction distribution, taken radially to the flow section, is the main parameter analysed as well as interfacial area concentration, interfacial gas velocity, and bubble sizes distribution. The CFD model implemented in this work demonstrates satisfactory agreement with the reference experimental data but indicates the need for further improvement in the phase interaction models.

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  • IPEN-DOC 29853

    BARROS, NATALIA G. de; GONZAGA NETO, ABEL C.; VACCIOLI, KLEBER B.; ANGULO, HUGO R.V.; SILVA, LEONARDO G de A. e ; TOFFOLI, SAMUEL M.; VALERA, TICIANE S.. Graphene oxide: a comparison of reduction methods. C-Journal of Carbon Research, v. 9, n. 3, p. 1-17, 2023. DOI: 10.3390/c9030073

    Abstract: This paper presents a comparison of traditional thermal and chemical reduction methods with more recent ionizing radiation reduction via gamma rays and electron beams (e-beams). For GO, all synthesis protocols were adapted to increase production scale and are a contribution of this work. The typical Raman D-band of the GO was prominent (ID/IG ratio increased sixfold). When comparing the GO reduction techniques, dramatic differences in efficiency and GO particle characteristics were observed. Although thermal and chemical reduction are effective reduction methods, as shown through the use of FTIR spectroscopy and the C/O ratio from EDS chemical analysis, the thermal process renders great weight losses, whereas chemical processing may involve the use of hazardous chemical compounds. On the other hand, comparing the gamma rays and e-beam for 80 kGy, the Raman spectra and chemical analysis suggested that the e-beam caused a greater GO reduction: C/O ratio from EDS of 5.4 and 4.1, respectively. In addition to being fast and effective, ionizing radiation reduction processes allow easier control of the reduction degree by adjusting the radiation dose. When the dose increased from 40 to 80 kGy, the Raman spectra and EDS showed that the ID/IG and C/O ratios increased by 15 and 116%, respectively.

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  • IPEN-DOC 29851

    TEIXEIRA, LUIZ F.S. ; BELLINI, MARIA H. . NF-ĸΒ1 knockout reduces IL6 expression under hypoxia in renal cell carcinoma. Cellular and Molecular Biology, v. 69, n. 6, p. 8-14, 2023. DOI: 10.14715/cmb/2023.69.6.2

    Abstract: Renal cell carcinoma (RCC) is the most common adult renal epithelial cancer, accounting for more than 90% of all renal neoplasms. Clear cell RCC (ccRCC) is the most common subtype of RCC. Most patients with ccRCC have a mutation in the von Hippel-Lindau (VHL) tumor suppressor gene, which encodes a protein that downregulates various intracellular proteins, including hypoxia-inducible factor (HIF). Many molecules have been identified to be responsible for the aggressive phenotype of ccRCC, including the transcription factor nuclear factor kappa B (NF-кB). The increase in NF-кB activity observed in RCC is correlated with an increase in angiogenesis markers, such as interleukin 6 (IL-6). In recent years, several groups have demonstrated the functional role of NF-кB1 in RCC tumorigenicity. Herein, we used the CRISPR/Cas-9 technique to obtain an NF-кB1 knockout-human renal adenocarcinoma cell line. Expression of IL-6 at the mRNA and protein levels was analyzed under normoxia and hypoxia by real time-polymerase chain reaction and multiplex assay, respectively. The CRISPR/Cas9 technique was effective in producing 786-0 knockout cells for NF-κB1 (p105/p50), as confirmed by western blot analysis. Suppression of p50 expression in 786-0 single guide RNA (sg)1, 786-0 sg2 and 786-0 sg3 cells downregulated IL-6 mRNA and protein expression under normoxia and hypoxia. The observed decrease in the differential expression of IL-6 in hypoxia/normoxia is suggestive of a change in cellular responsiveness to hypoxia with respect to IL-6.

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  • IPEN-DOC 29850

    NASCIMENTO, F.C. ; MUNHOZ, P.M. ; NASCIMENTO, L.F.N.; CALVO, W.A.P. . Development of an acrylic emulsion paint added with cellulosic dispersion treated with an electron beam accelerator. Brazilian Journal of Radiation Sciences, v. 11, n. 3, p. 1-18, 2023. DOI: 10.15392/2319-0612.2023.2291

    Abstract: Paint is a prevalent type of surface of coating well known to most people. It is an easy-to-apply product, with excellent physical and chemical resistance and a wide range of applications. The function of a paint is to protect and beautify amongst other properties. Paints are formed using five components: resin, pigments, fillers, solvents and additives. This work deals with a specific type of paint, composed of a water-based acrylic emulsion, whose film formation is by coalescence and used to coat walls and other surfaces. The aim of this innovative research was to evaluate the effect of the addition of cellulosic dispersion of waste paper tissues treated by electron beam irradiation to an acrylic emulsion-based paint. The methodology used was a case study carried out at the Nuclear and Energy Research Institute that consisted of adding aqueous dispersions of cellulosic wipes with mass concentrations varying from 0.1% to 10% in deionized water, and treated by electron beam processing with absorbed doses from 5 kGy to 50 kGy. The results obtained followed the parameters of the Abrafati Sectorial Quality Program. The main sample parameters analyzed were specific density, which reached an average of 1.35 g/cm3 ; and covering power, whose value of 93.55% was above the specified limit (minimum of 90%). Among other results obtained, improvements in appearance, applicability and functionality were significant. It was concluded that this research constitutes an incremental improvement to the acrylic emulsion paints segment, and environmental sustainability, through the reuse of cellulosic tissue residues.

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  • IPEN-DOC 29849

    AYLLON, R.M. ; FURLAN, M.R.; EL HAJJ, T.M.; SILVA, P.S.C. . Th-232 radiological aspects of carbonate niobium mining waste use as agricultural amendment. Brazilian Journal of Radiation Sciences, v. 11, n. 1A, p. 1-21, 2023. DOI: 10.15392/2319-0612.2023.2223

    Abstract: The use of mining residues in agriculture may be possible, as long as there be previous studies in different areas, one of them being the analysis of the involved radionuclides behavior. This study determined the concentrations of 232Th activity in soil, soil treated with lime, soil with carbonate residue from niobium mining, soil with the mixture of lime and carbonate, in two moments. The transfer factor of 232Th from the soil to the plant was analyzed, in this case, lettuce (n=20), in the different types of treatment and in two moments. The addition of carbonate to the soils did not significantly alter the levels of radioactivity for 232Th radionuclide in lettuce. The effective dose resulting from the lettuce ingestion varied from 0.09 to 0.3 µSv y-1.

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  • IPEN-DOC 29848

    FUNGARO, D.A. ; GROSCHE, L.C. ; SILVA, P.S.C. . Physicochemical and radiological characterization of flue gas desulfuration waste samples from Brazilian coal-fired power plants. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-18, 2023. DOI: 10.15392/2319-0612.2023.2275

    Abstract: Flue gas desulfurization (FGD) waste is an industrial by-product generated during the flue gas desulfurization process in coal-fired power plants. This by-product contain trace quantities of naturally occurring radionuclides and elements such as As, Ba, Co, Cr, Zn. The characteristics of FGD waste are important for its reuse and are mainly depend on the desulfurization process. In this work, two types of FGD materials collected from three coal-fired power plants using semi-dry and wet processes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-ray fluorescence (XFR) and particle size analysis. The radioactive content of 238U, 232Th, 228Th, 226Ra, 228Ra, 210Pb and 40K and trace elements were also determined using Neutron activation analysis and Gamma-ray spectrometry. The major constituents for all samples were Ca, Si, S, Al and Fe. Wet FGD by-product presented also high magnesium content. The wastes contain mainly semi-hydrate calcium sulfite and calcium sulfate. The particle size of FGD from semi-dry process was lower than that from the wet process. The average activity concentration of 238U, 232Th, 226Ra, 210Pb, 228Ra, 228Th and 40K varied between were 50-71, 33-42, 28-52, 113-150, 26-33, 33-39, 161-390 Bq kg-1 , respectively. According to the results of leaching and solubilization tests, FGD samples were classified as non-hazardous and non-inert. The obtained data are useful for evaluation of possible applications of FGD by-products

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  • IPEN-DOC 29847

    ALVARENGA, T.S. ; FERNANDES, S.S.; PEREIRA, W.W.; MAYHUGH, M.R.; CALDAS, L.V.E. . Estimation of scattered radiation influence on neutron beams at a calibration laboratory using Monte Carlo simulation of a long counter. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-12, 2023. DOI: 10.15392/2319-0612.2023.2249

    Abstract: At the Neutron Calibration Laboratory (LCN) of IPEN/CNEN, a 241AmBe source was used to test and calibrate neutron detectors. The neutrons emitted by the source reach the detector as intended, but they also scatter undesirably from the building's floor, ceiling, and walls, leading to indirect detection. A Long Counter (LC) detector was modeled using the MCNPX Monte Carlo code. The objective of this study was to measure the contribution of scattered radiation at the LCN / IPEN, and to determine the fluence rate, at different points in the calibration room at source-to-detector distances of 100 cm and 150 cm; subsequently, the results were compared with those of the Brazilian Laboratory of Metrology of Ionizing Radiation (LNMRI). The results show that the fluence rates of LCN / IPEN are comparable to those of this neutron laboratory for the 100 and 150 cm source-to-detector distances using a 241AmBe source (37 GBq). The results show that the calibration of neutron detectors should be performed at distances less than 100 cm, where the contribution of scattered radiation is within the 40% limit recommended by ISO 8529-1.

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  • IPEN-DOC 29846

    AQUINO, S. ; LIMA, J.E.A.; BORRELY, S.I. . Combined application of gamma radiation, cleaning and chemical sanitizers in decontamination of vehicle air conditioning filters. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-11, 2023. DOI: 10.15392/2319-0612.2023.2244

    Abstract: This work aimed to analyze the fungal contamination of air-conditioning filter waste (n=15) as an indicator of Quality Air Indoor from different car models in São Paulo city in São Paulo State, Brazil, during the period from October 2018 to July 2019. Three different treatments were used for the decontamination of car air conditioning filters, such as mechanical vacuum cleaning (I), vacuum cleaning and use of sanitizing product (II), and sanitizing product associated with radiation treatment at a dose of 17 kGy (III). After the treatments, microbiological analyses were performed and samples were plated in Petri dishes containing Sabouraud agar transferred by Swabs, and incubated for 7 days at 25 °C. The Petri dishes were stored in a standard Biochemical Oxygen Demand incubator, for the growth of fungal cultures. After incubation, the fungal cultures were evaluated, and the fungal counting was expressed in unit-forming colonies (UFC) and frequency in samples (%). The fungi were examined by lactophenol blue solution staining for microscopy. All samples of treatment I and II were contaminated with various fungal genera and high bioburden, namely (treatment I) Alternaria alternata, Aspergillus flavus, A. niger, Cladosporium spp., Fusarium spp., Mucor spp., Nigrospora spp., Not Sporulated Fungi (NSF), Penicillium spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp. and yeasts. Treatment II showed Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. ochraceus, Cladosporium spp., Mucor spp., NSF, Penicillium spp., Phoma spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp., and yeasts. Treatment III presented NSF and yeasts, with 80% of material decontamination.

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  • IPEN-DOC 29845

    GASPARIAN, P.B.R. ; MALTHEZ, A.L.M.C.; MARIANO, L.; CAMPOS, L.L. ; POLITANO, R. . An overview study on the TL and OSL dosimetry patent processes over time. Brazilian Journal of Radiation Sciences, v. 11, n. 1, p. 1-15, 2023. DOI: 10.15392/2319-0612.2023.2107

    Abstract: Since its discovery, ionizing radiation has been used in many different applications. Materials and methods have been developed to measure and quantify radiation doses. Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are two techniques used for radiation dosimetry. Both TL and OSL are primarily applied in several areas, such as dating of ancient materials, equipment quality control and individual monitoring. One of the parameters to measure the knowledge and development of a technology is the number of patents related to the field. In this work, we established a methodology for patent search on the World Intellectual Property Organization (WIPO) database aiming to review the development of TL and OSL dosimetry over time. We concluded that along with the OSL technique development, the TL technique should continue to be explored in radiation dosimetry.

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  • IPEN-DOC 29844

    MARTINS, E.W. ; POTIENS, M.P.A. . Activimeter “in situ” calibration methodology to 111In and 123I. Brazilian Journal of Radiation Sciences, v. 11, n. 1A, p. 1-9, 2023. DOI: 10.15392/2319-0612.2023.2212

    Abstract: The activimeter calibration has the purpose of ensure greater reliability in measurement results, hence the activimeters used are commonly installed in controlled areas and, in some cases, with difficult access. The activimeter “in situ” calibration methodology presented in this work allows its execution only with the displacement of the radioactive samples and not of the activimeter itself, which simplifies the procedure of nuclear medicine services and at radiopharmaceuticals production centers, without affecting the quality and accuracy of measurements. After the application of the methodology by qualified technicians, the obtained results of the tested activimeters showed its importance since the calibration factors can present correction of up to 5% for 111In and greater than 5% for 123I.

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  • IPEN-DOC 29841

    ROSSETTO, CLEUSA M.; CAREZZATO, GERALDO L. ; MARTINEZ, LUIS G. ; PECCHIO, MARCELO; TURRILLAS, XAVIER. Mineralogical analysis of Brazilian Portland cements by the Rietveld method with emphasis on polymorphs M1 and M3 of alite / Análisis mineralógico de cementos Portland de Brasil por el método de Rietveld con énfasis en los polimorfos M1 y M3 de la alita. Boletin de la Sociedad Espanola de Ceramica y Vidrio, v. 62, n. 5, p. 402-417, 2023. DOI: 10.1016/j.bsecv.2022.06.005

    Abstract: Eight samples of Portland cement and a clinker provided by the Brazilian Association of Portland Cement were analysed with different laboratory diffractometers and a synchrotron instrument to determine the statistical variability in the determination of the mass percentage of the main crystalline phases. Five laboratories participated in the experiment. Data collection was performed by each laboratory following its own internal procedures for a standard Rietveld analysis of mineral phases. Both Cu and Mo radiations were used. Reflection geometries—with and without sample rotation—and transmission geometries were also used. The synchrotron diffraction pattern was acquired from a rotating capillary and a wavelength of 0.41290 A. ˚ Analysis of all diffraction patterns was performed with the help of TOPAS Academic v. 6 with the specific purpose of determining the proportions of polymorphs M1 and M3 of alite, since their ratio must be taken into account for the subsequent development of the mechanical properties of concrete.

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  • IPEN-DOC 29840

    CABRAL, FERNANDA V. ; SOUZA, TIAGO H. dos S.; SALLERA, FABIO P.; FONTES, ADRIANA; RIBEIRO, MARTHA S. . Strengthening collaborations at the Biology‑Physics interface: trends in antimicrobial photodynamic therapy. Biophysical Reviews, v. 15, n. 4, p. 685-697, 2023. DOI: 10.1007/s12551-023-01066-5

    Abstract: The unbridled use of antimicrobial drugs over the last decades contributed to the global dissemination of drug-resistant pathogens and increasing rates of life-threatening infections for which limited therapeutic options are available. Currently, the search for safe, fast, and efective therapeutic strategies to combat infectious diseases is a worldwide demand. Antimicrobial photodynamic therapy (APDT) rises as a promising therapeutic approach against a wide range of pathogenic microorganisms. APDT combines light, a photosensitizing drug (PS), and oxygen to kill microorganisms by oxidative stress. Since the APDT feld involves branches of biology and physics, the strengthening of interdisciplinary collaborations under the aegis of biophysics is welcome. Given this scenario, Brazil is one of the global leaders in the production of APDT science. In this review, we provide detailed reports of APDT studies published by the Laboratory of Optical Therapy (IPEN-CNEN), Group of Biomedical Nanotechnology (UFPE), and collaborators over the last 10 years. We present an integrated perspective of APDT from basic research to clinical practice and highlight its promising use, encouraging its adoption as an efective and safe technology to tackle important pathogens. We cover the use of methylene blue (MB) or Zn(II) porphyrins as PSs to kill bacteria, fungi, parasites, and pathogenic algae in laboratory assays. We describe the impact of MB-APDT in Dentistry and Veterinary Medicine to treat diferent infectious diseases. We also point out future directions combining APDT and nanotechnology. We hope this review motivates further APDT studies providing intuitive, vivid, and insightful information for the readers.

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  • IPEN-DOC 29839

    ESQUIVEL-HERNANDEZ, GERMAIN; SANCHEZ-MURILLO, RICARDO; VILLALOBOS-CORDOBA, DIEGO; MONTEIRO, LUCILENA R. ; VILLALOBOS-FORBES, MARIO; SANCHEZ-GUTIERREZ, ROLANDO; COTRIM, MARYCEL E.B. ; MATIATOS, IOANNIS. Exploring the acid neutralizing effect in rainwater collected at a tropical urban area: Central Valley, Costa Rica. Atmospheric Pollution Research, v. 14, n. 9, p. 1-12, 2023. DOI: 10.1016/j.apr.2023.101845

    Abstract: We report on the chemical and the carbon isotopic composition of dissolved inorganic carbon (DIC) of rainwater collected between May and October 2020 in the Central Valley, Costa Rica. Precipitation samples were collected daily (N = 55) and analyzed for major ions, DIC, and δ13CDIC. Significant correlation (p < 0.05) between main acidic (SO4 2− and NO3 − ) and major alkaline (Ca2+ and NH4 +) species confirmed a very effective acid neutralization effect in rainwater (average pH: 5.90 ± 0.74). Significant temporal variations (p < 0.05) of δ13CDIC indicated the contribution of carbonate salts in rainwater from May to October but also CO2 dissolution at the beginning of the wet season (May), probably due to increased CO2 emissions from soil degassing. Temporal changes of Ca2+ neutralization factors followed the observed changes in δ13CDIC, which confirmed the high buffer capacity of precipitation in our study. HYSPLIT analysis also revealed long-range contributions of pedogenetic carbonates (e. g., Saharan dust) responsible for the acid neutralization capacity of rainwater (e.g., from July to September). Principal component analysis showed that four main factors explain 65% of the variance are: i) acid neutralization processes (Ca2+ neutralization factor), ii) marine salts (Cl− , Na+), iii) fossil fuels (SO4 2− , NO3 − ), and iv) agriculture/fertilizers (NO3 − , NH4 +, K+). Our study demonstrated that a combined approach of chemical, isotope, and statistical analysis techniques can help unravel the mechanism of acid neutralization of rainwater in tropical urban areas. This information has strong implications for future studies related with the impact of acid deposition on ecosystem functioning, water quality, and infrastructure degradation.

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  • IPEN-DOC 29837

    VIEIRA, ERICK V.R.; ROSARIO, NILTON E. do; YAMASOE, MARCIA A.; MORAIS, FERNANDO G.; MARTINEZ, PEDRO J.P.; LANDULFO, EDUARDO ; MIRANDA, REGINA M. de. Chemical characterization and optical properties of the aerosol in São Paulo, Brazil. Atmosphere, v. 14, n. 9, p. 1-21, 2023. DOI: 10.3390/atmos14091460

    Abstract: : Air pollution in the Metropolitan Area of São Paulo (MASP), Brazil, is a serious problem and is strongly affected by local sources. However, atmosphere column composition in MASP is also affected by biomass burning aerosol (BB). Understanding the impacts of aerosol particles, from both vehicles and BB, on the air quality and climate depends on in-depth research with knowledge of some parameters such as the optical properties of particles and their chemical composition. This study characterized fine particulate matter (PM2.5) from July 2019 to August 2020 in the eastern part of the MASP, relating the chemical composition data obtained at the surface and columnar optical parameters, such as aerosol optical depth (AOD), Ångström Exponent (AE), and single-scattering albedo (SSA). According to the analyzed data, the mean PM2.5 concentration was 18.0 ± 12.5 µg/m3 ; however, daily events exceeded 75 times the air quality standard of the World Health Organization (15 µg/m3 ). The mean black carbon concentration was 1.8 ± 1.5 µg/m3 in the sampling period. Positive matrix factorization (PMF) identified four main sources of aerosol: heavy vehicles (42%), followed by soil dust plus local sources (38.7%), light vehicles (9.9%), and local sources (8.6%). AOD and AE presented the highest values in the dry period, during which biomass burning events are more frequent, suggesting smaller particles in the atmosphere. SSA values at 440 nm were between 0.86 and 0.94, with lower values in the winter months, indicating the presence of more absorbing aerosol.

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  • IPEN-DOC 29836

    MOREIRA, GREGORI de A. ; CACHEFFO, ALEXANDRE ; ANDRADE, IZABEL da S. ; LOPES, FABIO JULIANO da S. ; GOMES, ANTONIO A. ; LANDULFO, EDUARDO . Analyzing the influence of vehicular traffic on the concentration of pollutants in the city of São Paulo: an approach based on pandemic SARS-CoV-2 data and deep learning. Atmosphere, v. 14, n. 10, p. 1-16, 2023. DOI: 10.3390/atmos14101578

    Abstract: This study employs surface and remote sensing data jointly with deep learning techniques to examine the influence of vehicular traffic in the seasonal patterns of CO, NO2 , PM2.5, and PM10 concentrations in the São Paulo municipality, as the period of physical distancing (March 2020 to December 2021), due to SARS-CoV-2 pandemic and the resumption of activities, made it possible to observe significant variations in the flow of vehicles in the city of São Paulo. Firstly, an analysis of the planetary boundary layer height and ventilation coefficient was performed to identify the seasons’ patterns of pollution dispersion. Then, the variations (from 2018 to 2021) of the seasonal average values of air temperature, relative humidity, precipitation, and thermal inversion occurrence/position were compared to identify possible variations in the patterns of such variables that would justify (or deny) the occurrence of more favorable conditions for pollutants dispersion. However, no significant variations were found. Finally, the seasonal average concentrations of the previously mentioned pollutants were compared from 2018 to 2021, and the daily concentrations observed during the pandemic period were compared with a model based on an artificial neural network. Regarding the concentration of pollutants, the primarily sourced from vehicular traffic (CO and NO2 ) exhibited substantial variations, demonstrating an inverse relationship with the rate of social distancing. In addition, the measured concentrations deviated from the predictive model during periods of significant social isolation. Conversely, pollutants that were not primarily linked to vehicular sources (PM2.5 and PM10) exhibited minimal variation from 2018 to 2021; thus, their measured concentration remained consistent with the prediction model.

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  • IPEN-DOC 29835

    KOSKINAS, MARINA F. ; MOREIRA, DENISE S. ; YAMAZAKI, IONE M. ; COLONNO, MARCELO ; SEMMLER, RENATO ; MORAIS, THALES S.L. ; DIAS, MAURO S. . Primary standardization and Monte Carlo modeling of ( 243Am + 239Np) by means of a 4π(PC)-γ coincidence counting system. Applied Radiation and Isotopes, v. 202, p. 1-7, 2023. DOI: 10.1016/j.apradiso.2023.111070

    Abstract: The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN for the primary standardization of a ( 243Am + 239Np) solution, in secular equilibrium, is described. The measurement was carried out in a 4π(PC) (α,β)− γ coincidence system. The total activity per unit mass of the solution was determined by the extrapolation technique, using a software coincidence counting systsem. The extrapolation curves were compared with Monte Carlo calculations by means of Code ESQUEMA, used in previous works, which, was improved and applied in order to calculate the alpha, beta, gamma, X-rays and coincidence spectra.

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  • IPEN-DOC 29834

    SILVA, ANDERSON M.B.; JESUS, LAIS S.; CORREA, WENDER; JUNOT, DANILO O.; CALDAS, LINDA V.E. ; DANTAS, NOELIO O.; SOUZA, DIVANIZIA N.; SILVA, ANIELLE C.A.. Luminescence characterization of BioGlass undoped and doped with europium and silver ions. Applied Radiation and Isotopes, v. 201, p. 1-7, 2023. DOI: 10.1016/j.apradiso.2023.110997

    Abstract: The objective of this study was to investigate the properties of BioGlass, with and without doping with europium and silver, with a specific focus on its potential application in thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimetry. The structural and optical characteristics of the samples were also analyzed using techniques such as X-ray diffraction (XRD), optical absorption (OA), and fluorescence spectroscopy (FL). An XRD analysis confirmed the amorphous phase of the BioGlass. OA and FL spectra were obtained at room temperature, and characteristic bands of dopant ions were observed which confirmed the incorporation of the Eu3+ ions and silver nanoparticles Ag(NP) ion into the BioGlass. The OSL decay curves exhibited a characteristic exponential behavior, with a notable presence of fast and medium decay components; this suggests that the charge traps within the BioGlass samples possess a high photoionization cross section when exposed to blue LEDs, which are commonly used as the light source in OSL readers. Different TL glow peaks with varying shapes of the glow curve were observed when the dopant, the co-dopant, and the concentration of silver were altered in the samples. The TL kinetic parameters were determined, such as the order value, activation energy, and frequency factor, and the OSL parameters for the compound were also analyzed, including an exponential fit to the curves. Based on these initial results, we conclude that BioGlass has the potential for use in radiation dosimetry.

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  • IPEN-DOC 29833

    SILVA, ANDERSON M.B.; RODRIGUES, DANIEL S.; ANTONIO, PATRICIA L. ; JUNOT, DANILO O.; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.. Investigation of dosimetric properties of CaSO4:Mn phosphor prepared using slow evaporation route. Applied Radiation and Isotopes, v. 199, p. 1-9, 2023. DOI: 10.1016/j.apradiso.2023.110874

    Abstract: The objective of this work was to investigate the luminescent properties of CaSO4:Mn synthesized by slow evaporation route. The crystalline structure, morphology, thermal and optical properties of the phosphors were characterized by X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM), photoluminescence (PL) and thermogravimetric analysis (TGA). Moreover, using thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques, the dosimetric properties of the phosphors, such as emission spectra, glow curve reproducibility, dose-response linearity, fading of the luminescent signal, variation of the TL intensity with the heating rate, OSL decay curves, correlation between TL and OSL emissions and minimum detectable dose (MDD) were comprehensively investigated. For dosimetric analyses, the samples were irradiated with doses from 169 mGy to 10 Gy. The emission band fits with the characteristic line of the Mn2+ emission features, ascribed to 6 A1→4 T1 transition. CaSO4:Mn pellets present a TL glow curve with a single typical peak centered around 494 nm, an OSL decay curve with predominance of a fast decay component, and a MDD on the order of mGy. The luminescent signals showed to be linear and reproducible in the studied dose range. The trapping centers located between 0.83 eV and 1.07 eV were revealed for different heating rates in the TL study. The high TL sensitivity of CaSO4:Mn was proven when comparing with commercially available dosimeters. The luminescent signals exhibit a smaller fading than described in the literature for CaSO4:Mn produced by other methods.

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  • IPEN-DOC 29832

    COSTA, OSVALDO L. da ; BARCELLOS, HENRIQUE ; MATSUDA, HYLTON ; SUMIYA, LUIZ C. do A. ; JUNQUEIRA, FERNANDO de C. ; MATSUDA, MARGARETH M.N. ; LAPOLLI, ANDRE L. . A new 124Xe irradiation system for 123I production. Applied Radiation and Isotopes, v. 200, p. 1-7, 2023. DOI: 10.1016/j.apradiso.2023.110926

    Abstract: Since 2001, Nuclear and Energy Research Institute IPEN-CNEN has produced weekly ultrapure iodine-123, using a manual irradiation system, fully developed in IPEN. Iodine-123 radiopharmaceuticals have been produced and distributed to hospitals and clinics of nuclear medicine, where several diagnostic imaging procedures for thyroid, brain and cardiovascular functions are performed. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. In the present work, the technical and constructive aspects of a new fully automated irradiation system, dedicated to 123I routine production, employing enriched xenon-124 gas as the target material is presented. This new system consists of a target, a water and helium cooling system, a cryogenic system, an electric power system, and a control and process monitoring unit, composed of supervisory software, connected to a programmable logic controller via personal computer. In this new concept, there is no need for human intervention during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. By using this new system, a specific yield of 2.70 mCi/μAh per irradiation was achieved in validation runs, and after three years of routine production of iodine- 123, the system showed reliability and resilience.

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  • IPEN-DOC 29831

    GOMES, DANIEL de S. . Overview of the physical properties of molten salt reactor using FLiBe. Journal of Engineering Research, v. 3, n. 36, p. 1-12, 2023. DOI: 10.22533/at.ed.3173362325107

    Abstract: Currently, there are six Generation IV nuclear reactor designs in development. Four are fast neutron reactors, and all designs operate at higher temperatures that permit hydrogen production. Thus, the interest in fluoride salts has grown due to their hightemperature application in fission and fusion reactor designs. The aircraft propulsion project was the initial plan, which used molten salt as a coolant and was started by Bettis and Briant in the 1940s. The molten salt reactor has been designed to operate at temperatures of 700 to 800°C with fissile material dissolved in a molten fluoride salt composition. Molten fluoride salts are stable at high temperatures, show good thermodynamic properties, and can also dissolve actinides and fission products easily. It creates a candidate for a thorium reactor with more than 45% efficiency. The purpose of this work was to investigate the physical characteristics of two systems of fluoride salt combinations, namely LiF-BeF2 (FliBe) and LiF-NaF-KF (FliNaK), including melting temperature, density, and heat capacity. The aim is to characterize the advantages of the various designs proposed for Generation IV by reviewing properties evidenced by safety improvements and limitations.

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  • IPEN-DOC 29830

    CHEN, BINYU; BIANCOLLI, ANA L.G. ; RADFORD, CHASE L.; HOLDCROFT, STEVEN. Stainless steel felt as a combined OER electrocatalyst/porous transport layer for investigating anion-exchange membranes in water electrolysis. ACS Energy Letters, v. 8, n. 6, p. 2661-2667, 2023. DOI: 10.1021/acsenergylett.3c00878

    Abstract: Anion-exchange membrane water electrolysis (AEMWE) is a promising technology for low-cost, high-efficiency, green hydrogen production. The stability of the AEM is a critical issue but difficult to delineate in situ from degradation of the catalyst layer (CL). Moreover, the porous transport layer (PTL) can contribute electrocatalytically. Herein, we demonstrate that stainless steel (SS) felt, in the absence of an anode CL, is highly active toward the oxygen evolution reaction (OER) (1 A cm–2 at 1.74 Vcell) and serves as a combined OER electrocatalyst and PTL, thus simplifying the study of AEMs in water electrolyzers. We further show that Ni felt exhibits much lower OER activity than SS felt, which suggests that in situ studies of OER electrocatalysts and CL compositions should be performed with Ni felt, not SS felt, to reduce OER contributions from the PTL. Lastly, we found that the substrate for depositing the cathode CL, AEM, or PTL strongly influences the rate of H2 crossover.

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  • IPEN-DOC 29829

    TATUMI, SONIA H.; YEE, MARCIO; SOARES, EMILIO A.A.; SOUZA, JEFFERSON J. de; GRUDZIN, EMANUELE D.O.; MUNITA, CASIMIRO S. ; RIBEIRO, ROGÉRIO B. ; SOARES, ALVARO de F.; SILVA, NOEMI A.; FERNANDES, CAROLINE P.; MATHIAS, MATHEUS T.; ROCCA, RENE R.; NAGABHUSHANA, K.R.; LOKESHA, H.S.; ROCHA, MARCELO S.; LOPEZ, LUIS A.C.; VENANCIO, DIEGO W.P.; COSTA, SOLANGE dos S.. Radiometric and stimulated luminescent characterization of Amazonian sediments from the Middle Rio Negro, Western Amazon. Radiation Physics and Chemistry, v. 212, p. 1-12, 2023. DOI: 10.1016/j.radphyschem.2023.111117

    Abstract: The sediments were collected from paleodunes, river terraces, islands, and sand bars at Mariuá Archipelago, Rio Negro, Brazil. XRD analysis revealed that quartz is the predominant mineral along with a trace quantity of kaolinite. Neutron activation analysis of the sediments revealed the assembly of rare-earth elements, metals and semi-metals. The values of U and Th were found to be 3–5 ppm in paleodunes and 9–16 ppm in terraces, and K-40 concentration is below detectable limit. The OSL of quartz (dune) is composed of three components with decay times of 0.2, 11.0 and 350 s, respectively. This OSL emission is related to the TL peaks below 380 °C. Also, photo-transferred TL is observed in the temperature range of 190–250 °C for a blue stimulation of 500 s. TL peaks kinetic parameters were calculated and discussed. The lifetimes of TL peaks at 272 and 355 °C are approximately 4.0×104 and 1.5×109 years, respectively. Using the conventional SAR protocol, 11 samples were dated, including two old paleodunes with ages of 124.4 and 169.7 ka, increasing the age interval of the site, the other samples were younger sediments, with ages between 0.39 and 53.9 ka.

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  • IPEN-DOC 29828

    COSTA, ANGISLAINE; GOMES, DENISE M.C.; MUNITA, CASIMIRO ; KIPNIS, RENATO; RIZZUTTO, MARCIA de A.. A produção de cerâmica no alto rio Madeira (séculos XI-XIII AD): uma abordagem das interações indígenas com a paisagem por meio das técnicas físico-químicas / Ceramic production at the upper Madeira river (11th-13th AD): an approach on indigenous interactions with the landscape with physical-chemical techniques. Revista de Arqueologia, v. 36, n. 2, p. 122-139, 2023. DOI: 10.24885/sab.v36i2.1055

    Abstract: O uso das técnicas físico-químicas tem auxiliado nos estudos de proveniência e composição química das pastas dos artefatos cerâmicos, e, por consequência, nas classificações dos conjuntos arqueológicos. A partir da análise por ativação com nêutrons (AAN) e do sistema portátil de fluorescência de raios X por dispersão de energia (EDXRF) discutimos a caracterização das argilas utilizadas na produção de vasilhas de sete sítios arqueológicos pré-coloniais situados na região do alto rio Madeira. As assinaturas isotópicas e os elementos químicos identificados apontam uma diferenciação nas escolhas culturais das fontes de argilas pelos produtores das cerâmicas classificadas como Dionísio, da Tradição Polícroma da Amazônia (TPA) e Santo Antônio. Estas duas últimas correspondem a uma mesma fonte de argila. A partir de uma abordagem integrada, que associa análises microscópicas, estilísticas, formais, tecno-funcionais, esses estudos arqueométricos contribuíram para uma discussão mais ampla sobre as interações culturais dos povos indígenas e destes com a paisagem entre os séculos XI e XIII AD.

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  • IPEN-DOC 29826

    AQUINO, SIMONE ; CAVALCANTE, CRISTIANE das G.D.; ZAJAC, MARIA A.L.; LOPES, EVANDRO L.. Environmental challenges of a Brazilian basic health unit in managing sharp waste produced by diabetics in domestic use. International Journal of Social Ecology and Sustainable Development, v. 13, n. 1, p. 1-14, 2022. DOI: 10.4018/IJSESD.305124

    Abstract: The goal of this study was to analyze the management and reverse logistics of sharp wastes, such as needle syringes and lancets, from domestic use by insulin-dependent diabetics, which were attended by the Brazilian Unified Health System. This is an exploratory case study, carried out by from data collected from 233 insulin-dependent diabetics and interviews with a health professional from October 2014 to September 2015. It was estimated that, in one year, 68% of insulin users received standard biosafety boxes below the necessary quantity for the disposal of needles, syringes, and lancets. Around 1,300 kg of sharp wastes were generated and only 1,831 boxes were distributed, showing a deficit in the reverse logistic system and indicating that sharp residues were incorrectly disposed of in residential garbage. A new Brazilian model to distribute the standard biosafety boxes to diabetics to guarantee the correct environmental disposal of sharp wastes is necessary.

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  • IPEN-DOC 29824

    SOARES, HUMBERTO V. ; YAMAGUCHI, MITSUO ; BELCHIOR JUNIOR, ANTONIO ; ANDRADE, DELVONEI A. de ; UMBEHAUN, PEDRO E. ; TORRES, WALMIR M. . Cálculo das densidades de potência no elemento combustível ECI-RMB. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEENG, Agosto, 2023. (IPEN-CEN-P&D-INTC-003-00-RELT-003-00). Restrito.

    Título do projeto: Intercentros 2020.06.IPEN.45.PD

    Abstract: Este relatório apresenta a metodologia utilizada para o cálculo neutrônico e das densidades de potência no Elemento Combustível Instrumentado ECI-RMB. O projeto de avaliação do ECI-RMB tem como objetivo analisar o comportamento deste Elemento no núcleo do Reator IEA-R1, e posteriormente permitirá a realização de testes não destrutivos (espectrometria gama, medida de espessura e inspeção visual) das placas combustíveis removíveis, representativas do reator RMB. Essa primeira fase do projeto consiste em fazer cálculos computacionais utilizando os códigos TwoDB ou (2DB) e o CITATION, já utilizados no IPEN ao longo das últimas décadas. Com esses códigos, foi possível calcular a distribuição de potência individualmente nas placas combustíveis do ECI-RMB. Por se tratar de um Elemento Combustível fora do padrão dos ECs usados no IEA-R1 (3,0 gU/cm3) e que usa uma densidade de urânio maior (3,7 gU/cm3), o ECI-RMB terá comportamentos de geração de calor e termo-hidráulicos levemente diferentes. Os resultados de distribuição de potência nas placas combustíveis do ECI-RMB mostraram potências maiores, da ordem de 4,95% em média, nas placas RMB, como esperado, pois possui uma maior densidade de urânio. A princípio, essas potências maiores nas placas RMB não devem afetar na segurança do núcleo do IEA-R1 e do próprio ECI-RMB. Análises termo-hidráulicas serão realizadas com essa distribuição de potência para confirmação da segurança do núcleo e do ECI-RMB.

    Palavras-Chave: power density; fuel elements; rmb reactor; fuel plates

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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


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

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

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

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

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