Navegação por ano de publicação "2019"

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  • IPEN-DOC 25841

    VIEIRA, LUDMILA C. ; ARAUJO, LEANDRO G. de; FERREIRA, RAFAEL V. de P.; SILVA, EDSON A. da; CANEVESI, RAFAEL L.S.; MARUMO, JULIO T. . Uranium biosorption by Lemna sp. and Pistia stratiotes. Journal of Environmental Radioactivity, v. 203, p. 179-186, 2019. DOI: 10.1016/j.jenvrad.2019.03.019

    Abstract: Biosorption-based technologies have been proposed for the removal of radionuclides from radioactive liquid waste containing organic compounds. Nevertheless, pytoremediation potential of uranium (U) by nonliving aquatic macrophytes Lemna sp. and Pistia stratiotes has not been previously addressed. In this study, uranium biosorption capacity by Pistia stratiotes and Lemna sp. was evaluated by equilibrium and kinetics experiments. The biomasses were added to synthetic and real waste solutions. The assays were tested in polypropylene vials containing 10 mL of uranium nitrate solution and 0.20 g of biomass. Solutions ranging from 0.25 to 84.03 mmol l−1 were employed for the assessment of uranium concentration in each macrophyte. The equilibrium time was 1 h for both macrophytes. Lemna sp. achieved the highest sorption capacity with the use of the synthetic solution, which was 0.68 mmol g−1 for the macrophyte. Since Lemna sp. exhibit a much higher adsorption capacity, only this biomass was exposed to the actual waste solution, being able to adsorb 9.24×10−3 mmol g−1 U (total). The results show that these materials are potentially applicable to the treatment of liquid radioactive waste.

    Palavras-Chave: sorption; uranium; biomass; adsorption; organic compounds; aquatic ecosystems; plants; radioactive wastes

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  • IPEN-DOC 26700

    LOPES, THIAGO ; BERUSKI, OTAVIO ; KORKISCHKO, IVAN ; MANTHANWAR, AMIT M.; PISTIKOPOULOS, EFSTRATIOS N.; FONSECA, FABIO C. ; MENEGHINI, JULIO R.; KUCERNAK, ANTHONY R.. Unveiling fundamental transport phenomena in fuel cells. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: In situ and ex situ spatially-resolved techniques are employed to investigate reactant distribution and its impacts in a polymer electrolyte fuel cell. Temperature distribution data provides further evidence for secondary flows inferred from reactant imaging data, highlighting the contribution of convection in heat as well as reactant distribution. Water build-up from neutron tomography is linked to component degradation, matching the pattern seen in the reactant distribution and thus suggesting that high, nonuniform local current densities shape degradation patterns in fuel cells. The correlations shown between different techniques confirm the use of the versatile reactant imaging technique, which is used to compare commonly used flow field designs. Among serpentine-type designs, the single serpentine is superior in both equivalent current density and reactant distribution, showing large contributions from convective flow. On the other hand, the interdigitated design is shown to produce larger equivalent current densities, while showing a somewhat poorer reactant distribution. Considering the correlations drawn between the techniques, this suggests that the interdigitated design compromises durability in favour of power output. The results highlight how established techniques provide a robust background for the use of a new and flexible imaging technique toward designing advanced flow fields for practical fuel cell applications.

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  • IPEN-DOC 27443

    CASSOL, HENRIQUE L.G.; DOMINGUES, LUCAS G. ; BASSO, LUANA S.; GATTI, LUCIANA V. ; MARANI, LUCIANO; TEJADA, GRACIELA; ARAI, EGIDIO; MILLER, JOHN B.; ANDERSON, LIANA O.; ARAGAO, LUIZ E.O.C.. Understanding the temporal dynamics of carbon emission from fires in the Amazon-Cerrado transition zone. Biodiversidade Brasileira, v. 9, n. 1, p. 132-132, 2019. DOI: 10.37002/biobrasil.v%25vi%25i.1273

    Abstract: Carbon emissions from fires (C fire) account for one-tenth of the global annual C emissions. Fires are the main source of emissions from land-use change. Recently, Werf et al. 2017, showed an 11% increase in global fire emissions during the 1997-2016 period. Savannas and Tropical Forests have shared almost the same fire-derived C emission values in the South America (Werf et al. 2017). Therefore, for this study we focused our analysis on a site representing the transition zone between Amazonia and Cerrado, located in Alta Floresta (ALF) in Mato Grosso State, Brazil. To understand the temporal dynamics of fire-derived C emission, we correlated fire counts (FC) within the influence area with fire-derived C emission directly measured in the atmosphere as CO concentration. CO and CO2 were collected monthly for 7 years from 2010 onwards using an aircraft flying up to 4.5 km altitude, totaling 153 vertical profiles. FC was extracted from influence areas weighted by the density of backward trajectories calculated quarterly. Trajectories starting from the flight location within a cell of one degree resolution were obtained using the Hysplit model at different heights. The average annual C emission from fire was 0.10 ± 0.04 Pg.C.yr-1, which represents about 10% of the Amazon fire emissions (Aragão et al. 2018). The highest daily value of fire emission was observed in 2010 (drought year) and 2017 (0.47-0.51 gC.m².day-1), although the years of 2011, 2016, and 2017 were the largest contributor to the total emission flux. This occurred because the influence area that belongs to the Amazon was lower in those years. Inter annually there is a typical behavior of the backward trajectories in ALF site whose 1st and 4th quarters have 80% of the air-streams coming from the Amazon, while during the 2nd and 3rd quarters this contribution is about 45%. However, emissions from fire and FC are higher in the 3rd quarter, outside the Amazon. The correlation between FC and fire emission was positively significant (ρ = 0.88, α = 0.05, p<0.001), meaning that an increase of 1,000 FC per quarter causes an increase of 0.074 gC.m².day-1 or, on average, an emission of 0.16 Pg.C.yr-1.

    Palavras-Chave: fires; carbon dioxide; emission; forests; greenhouse gases; environment

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  • IPEN-DOC 27958

    BASSO, LUANA S.; GATTI, LUCIANA V. ; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; DOMINGUES, LUCAS G. ; CORREIA, CAIO S. de C. ; IPIA, ALBER; ARAI, EGIDIO; ARAGAO, LUIZ E.O.C.; ANDERSON, LIANA O.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; GLOOR, MANUEL; MILLER, JOHN B.. Understanding the seasonality and interannual variability of Amazon CH4 budget and climate feedbacks based on atmospheric data from vertical profiles measurements. In: AGU CHARPMAN CONFERENCE, August 26-29, 2019, San Diego, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Currently tropical land regions, like Amazon, are still poorly observed with large-scale integrating in-situ observations although they host some of the largest wetlands/seasonally flooded areas on the globe. The role of these regions in the global CH4 balance and the climate feedbacks have remained uncertain. To help this situation we have started a lower-troposphere greenhouse gas-monitoring program over tropical South America consisting of regular vertical profile greenhouse gas and carbon monoxide (CO) observations at four sites along the main airstream since 2010. Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and carbon monoxide analysis of flask air, fortnightly between 2010 to 2017. Over the full period the Amazon (total area of around 7.2 million km2) was a source of CH4, of approximately 46 ± 6 Tg/year, which represent 8% of the global CH4 flux to the atmosphere. CH4 emissions from different parts of the basin vary markedly. There are comparably high emissions from the eastern part of the basin exhibiting strong variability, with particularly high CH4 fluxes in the early part of the wet season (January to March). A second period of high emissions occurs during the dry season. The cause of the high emissions is unclear. In contrast to the eastern Amazon site a clear seasonality was observed at the other three sites located further downwind along the main sir-stream, with the largest emissions occurring at the beginning of the wet season (January to March). In addition, these data show an interannual variability in emissions magnitude, so we discuss how these data can be correlate to temperature, precipitation, terrestrial water storage anomalies (from GRACE) and Fire counts (human-driven changes) that could be influencing this variability. Using a CO/CH4 emission ratio calculated in this study we find a biomass burning contribution varying between 10 and 23% of the total flux at each site. Also, we discuss what the data tell us about possible ongoing feedbacks to possible changes in temperature, precipitation and biomass burning and indicating what variables can be contributing to CH4 emissions from Amazon.

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  • IPEN-DOC 27442

    TEJADA, GRACIELA; GATTI, LUCIANA ; BASSO, LUANA; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO ; DOMINGUES, LUCAS ; CRISPIM, STEPHANE; NEVES, RAIANE; ANDERSON, LIANA O.; ARAGAO, LUIZ E.O.C.; ARAI, EGIDIO; GLOOR, MANUEL; MILLER, JOHN B.; VON RANDOW, CELSO. Understanding the relationships between local deforestation and CO2 atmospheric measurements in the Brazilian Amazon. Pesquisa Florestal Brasileira - Brazilian Journal of Forestry Research, v. 39, Special issue, p. 528-528, 2019. DOI: 10.4336/2019.pfb.39e201902043

    Abstract: Amazon forests play a fundamental role in the global carbon balance as a carbon sink, but temperature elevations and frequents extreme events as droughts and floods could make the forests a source of CO2. Local atmospheric measurements of greenhouse gases are needed to better understand how forest will respond to climate change. The lower-troposphere greenhouse gas (GHG) monitoring program over Brazilian Amazon Basin, has been collecting biweekly GHGs vertical profiles in four sites since 2010. We aim to understand the relationships between local deforestation and CO2 aircraft measurements in the Brazilian Amazon. We calculated annual deforestation (using the Amazon Deforestation Calculation Program - PRODES), land use and cover change data (using the Brazilian Institute of Geography and Statistics - IBGE) and fire data (using the Fire Monitoring System) in each annual influence area at the four flight measurement sites of the Brazilian Amazon from 2010-2017 (and also in the mean influence area of all years by sites). We found that when we see total deforestation, it has a relationship with global CO2 emissions in the Brazilian Amazon biome. Fire has a strong relationship in the drought years, mostly in 2012. Looking at each site, we found specific correlations with deforestation, fire and land use. The biggest challenge was to compare spatial analyzes of land use change and fire with punctual data of airplane GHGs measurements. This study will contribute in our understanding of anthropogenic activities over the Amazon forest in a changing climate.

    Palavras-Chave: deforestation; greenhouse gases; monitoring; environment; atmospheres; carbon dioxide; emission

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  • IPEN-DOC 26750

    ORTIZ, N. ; NICOLAU, T.S. ; SOUZA, J.P. ; SILVA, A.. Ultrasonic TiO2 solar photodecomposition and biocarbon sorption processes to remove amoxicillin and cephalexin from binary systems. In: IWA INTERNATIONAL CONFERENCE ON WATER RECLAMATION AND REUSE, 12th, June 16-20, 2019, Berlin, Germany. Resumo expandido... 2019.

    Abstract: The cephalexin (CEPH) and amoxicillin (AMOX) antibiotics are the most indicated in the medical prescriptions in Brazil, as the antibiotics used for public health assistance and also for veterinary medicine. Nowadays Brazil is a higher protein animal producer in the world. After the metabolization, the antibiotics discharge in the sewage system and manure composition on rural areas; act as secondary pollution sources for surface water resources. The integrated processes applying the ultrasonic source before the solar photodecomposition and biosorption showed the maximum removal percentage of 91.47% for AMOX and 90.62% for CEPH. Considering the binary systems with the 17:83 proportion percentages of AMOX and CEPH the removal percentage was 89.15% and 97.90% respectively. The use of low-frequency ultrasonic waves before the solar photodecomposition increased the TiO2 surface area and effectiveness and enhanced the removal efficiency for both cephalexin and amoxicillin alone and in binary mixtures.

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  • IPEN-DOC 25840

    APPANNABABU, S.; LICHTENTHALER, R.; ALVAREZ, M.A.G.; RODRIGUEZ-GALLARDO, M.; LEPINE-SZILY, A.; PIRES, K.C.C.; SANTOS, O.C.B.; SILVA, U.U.; FARIA, P.N. de; GUIMARÃES, V.; ZEVALLOS, E.O.N.; SCARDUELLI, V.; ASSUNÇÃO, M.; SHORTO, J.M.B. ; BARIONI, A.; ALCANTARA-NUNEZ, J.; MORCELLE, V.. Two-neutron transfer in the He-6 + Sn-120 reaction. Physical Review C, v. 99, n. 1, p. 014601-1 - 014601-7, 2019. DOI: 10.1103/PhysRevC.99.014601

    Abstract: A large yield of α particles produced in the 120Sn(6He, α) reaction was measured at 20.3-, 22.2-, 22.4-, and 24.5-MeV bombarding energies. The α particles are distributed over a broad energy range in the vicinity and below the elastic scattering 6He peak. Energy integrated α-particle cross sections have been obtained at θlab = 36◦, 40◦, and 60◦. The α energy distributions have been analyzed at a fixed laboratory angle (≈60◦) in terms of the reaction Q value, considering the 2n-transfer reaction kinematics 120Sn(6He, α)122Sn. A kinematical analysis of the Q-value distribution shows that the recoil system 120Sn + 2n is formed in highly excited states in the continuum, at increasing excitation energies as the bombarding energy increases. It is shown that by using Brink’s formula, the excitation energy depends on the transferred angular momentum following a linear relation with the square of the angular momentum, indicating that some kind of dinuclear rotating system is formed after the reaction.

    Palavras-Chave: two-nucleon transfer reactions; neutron transfer; alpha particles; helium 6 reactions; tin 120 reactions; nuclear reactions; radioactive ion beams

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  • IPEN-DOC 26111

    UMBELINO, U.; PIRES, K.C.C.; LICHTENTHALER, R.; SCARDUELLI, V.; SCOTTON, G.A.; LEPINE-SZILY, A.; GUIMARÃES, V.; LUBIAN, J.; PAES, B.; FERREIRA, J.L.; ALVAREZ, M.A.G.; SHORTO, J.M.B. ; APPANNABABU, S.; ASSUNÇÃO, M.; CONDORI, R.P.; MORCELLE, V.. Two-neutron transfer in 7Be + 9Be collisions. Physical Review C, v. 99, n. 6, p. 064617-1 - 064617-13, 2019. DOI: 10.1103/PhysRevC.99.064617

    Abstract: Elastic scattering and transfer cross sections for the 7Be + 9Be system have been measured at Elab = 23.1 MeV using the 7Be radioactive secondary beam produced at Radioactive Ion Beams in Brazil facility at the University of São Paulo. The elastic scattering has been measured by detecting the 7Be scattered at forward angles in the laboratory system. The transfer reaction 9Be(7Be, 9Be)7Be was identified by detecting the 9Be scattered at the same laboratory angles. The elastic angular distribution has been analyzed by optical model calculations using a Woods-Saxon form factor whose parameters have been varied to best reproduce the experimental data at forward angles. Coupled reaction channels calculations (CRC) have been performed to describe the transfer, considering the coupling to the transfer channel and including contributions to the ground state and to the first excited state of 7Be(1/2−; 429 keV) in the final state. The spectroscopic amplitudes used in the CRC calculation have been derived from shell-model calculations. Similar CRC calculations were applied to existing 9Be(p, t )7Be data to check the consistency of our results results for the (7Be, 9Be) transfer reaction.

    Palavras-Chave: beryllium 7; beryllium 9; elastic scattering; coupled channel theory; ion beams; neutrons; neutron beams; neutron transfer

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  • IPEN-DOC 26109

    COSTA, ISRAEL F.; MOURA, JANDEILSON L.; ADERNE, RIAN E.; AVILA, HAROLD C.; CREMONA, MARCO; BRITO, HERMI F.; FELINTO, MARIA C.F.C. ; FAUSTINO, WAGNER M.; TEOTONIO, ERCULES E.S.. Tuning emitting color of electroluminescent devices containing tris(2‑acyl‑1,3‑indandionate)aluminum(III) complexes as emitting layers. Journal of the Brazilian Chemical Society, v. 30, n. 8, p. 1647-1656, 2019. DOI: 10.21577/0103-5053.20190064

    Abstract: In this study, a novel type of tris(2-acyl-1,3-indandione)-aluminum(III) coordination compounds of the general formula [Al(acind)3]H2O, where 2-acyl-1,3-indandione (acind), 2-acetyl- 1,3-indandione (aind), 2-benzoyl-1,3-indandione (bind), and 4-methyl-2-benzoyl-1,3-indandione (mbind), were synthesized and characterized by elemental analysis (CHN), Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopies, thermal analysis (TG/DTG and DTA), and optical absorption spectroscopy in the UV-Vis region. These compounds present remarkably high green luminescence in powder and in thin-film forms. However, when these compounds are applied in glass/ITO/β-NPB/spiro-2CBP/[Al(acind)3]/Al and glass/ITO/β‑NPB/ [Al(acind)3]/LiF/Al electroluminescent devices, where spiro-2CBP is 2,7-bis(carbazol-9-yl)-9,9- spirobifluorene and β-NPB is N,N’-bis(naphthalen-2‑yl)-N,N’-bis(phenyl)-benzidine, the emission color tuned from green to red, reflecting a change from the direct charge recombination in the emitting layer of the [Al(acind)3] complexes to an exciplex-based emission in which [Al(acind)3] complexes and spiro 2-CBP acted as acceptor and donor, respectively. These results suggest that [Al(acind)3] complexes have potential applications as molecular light converter materials for fabricating new electroluminescent devices.

    Palavras-Chave: electroluminescence; light emitting diodes; tuning; fourier transformation; infrared spectra; aluminium complexes; wavelengths

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  • IPEN-DOC 25839

    ESPOSITO, VINCENZO; KABIR, AHSANUL; ROSA, MASSIMO; NONG, NGO V.; RODRIGUES, THENNER S. ; RODRIGUES, LAYS N. ; MACHADO, MARINA F.S. ; MORAES, LETICIA P.R. ; MARANI, DEBORA; FONSECA, FABIO C. . Tuning diffusion paths in shaped ceria nanocrystals. CrystEngComm, v. 21, n. 27, p. 4025-4029, 2019. DOI: 10.1039/c9ce00414a

    Abstract: Mass diffusion controls material structuring from the atomic to the macro-scale defining properties and functionalities. We show here that surface energy in Ce0.9Gd0.1O3-d shaped nanocrystals, i.e. nanocubes, nanorods and spherical nanoparticles, can control solid state diffusion mechanisms over a long range, leading to extreme microstructural diversity.

    Palavras-Chave: nanostructures; crystals; cerium oxides; diffusion; gadolinium; doped materials

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  • IPEN-DOC 25838

    COURROL, DANIELLA dos S.; LOPES, CARLA R.B.; PEREIRA, CAMILA B.P.; FRANZOLIN, MARCIA R.; SILVA, FLAVIA R. de O. ; COURROL, LILIA C.. Tryptophan silver nanoparticles synthesized by photoreduction method: characterization and determination of bactericidal and anti-biofilm activities on resistant and susceptible bacteria. International Journal of Tryptophan Research, v. 12, p. 1-8, 2019. DOI: 10.1177/1178646919831677

    Abstract: The high rates of antibiotics use in hospitals have resulted in a condition where multidrug-resistant pathogens have become a severe threat to the human health worldwide. Therefore, there is an increasing necessity to identify new antimicrobial agents that can inhibit the multidrugresistant bacteria and biofilm formation. In this study, antibacterial and anti-biofilm activities of tryptophan silver nanoparticles (TrpAgNP) were investigated. The TrpAgNPs were synthesized by photoreduction method, and the influence of irradiation time and concentration of reagents were analyzed. The nanoparticles were characterized by transmission electron microscopy, Zeta Potential and (UV)-absorption spectra. The antibacterial activity of TrpAgNPs was tested for antibiotic-resistant and susceptible pathogens, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Salmonella typhimurium, and Pseudomonas aeruginosa, evaluating the influence of photoreduction parameters in bactericidal effect. The results have shown that TrpAgNPs solutions with lower tryptophan/silver nitrate (AgNO3) ratio and higher AgNO3 concentration have higher bactericidal action against bacteria with inhibition of ~100% in almost all studied bacterial strains. The antimicrobial activity of TrpAgNPs within biofilms generated under static conditions of antibiotic-resistant and susceptible strains of S. aureus, S. epidermidis, E. coli, K. pneumoniae, C. freundii, and P. aeruginosa was also investigated. The results showed that TrpAgNPs have an inhibitory effect against biofilm formation, exceeding 50% in the case of Gram-negative bacteria (E. coli, K. pneumoniae, C. freundii, and P. aeruginosa—54.8% to 98.8%). For Gram-positive species, an inhibition of biofilm formation of 68.7% to 72.2 % was observed for S. aureus and 20.0% to 40.2% for S. epidermidis.

    Palavras-Chave: antimicrobial agents; silver; antibiotics; tryptophan; nanoparticles; irradiation; photosynthetic bacteria; photochemical reactions

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  • IPEN-DOC 26842

    PIERETTI, EURICO F. ; NEVES, MAURICIO M. das ; CORREA, OLANDIR V. ; ANTUNES, R.A.. Tribological evaluation of CoCrMo alloy for biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1836-1836.

    Abstract: The tribological behavior of the CoCrMo alloy was evaluated in the air in a nanotribometer. The chemical composition, microstructure and mechanical properties of CoCrMo alloys makes them potential materials for use as implantable medical or dental devices [1]. This work has a specific focus on covering the possible in vitro wear modes seen on metal-on metal surfaces. Ballcratering wear test was carried out for 10 min with a solid sphere of WC as counterbody, at a frequency of 75 rpm [2]. The CoCrMo samples’ citotoxicity was analyzed in order to determine if the alloy casting process and its surface finishing, current used in industry, affects the biomaterial’s biocompatibility. All tested surfaces were prepared according to the recommendations for clinical use. The results address the potential detrimental effects of hard particles in vivo such as increased wear rates (debris generation), which is greatly influenced by the normal force, and corrosion (metal-ion release). None sample was considered cytotoxic.

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  • IPEN-DOC 26213

    LINHARES, VANESSA do N. ; VICENTE, ROBERTO ; MARUMO, JULIO T. . Treatment of TENORM waste using surfactant. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1310-1317.

    Abstract: The petroleum industry is responsible by the generation of wastes that are both toxic and radioactive, sometimes called mixed waste. The toxicity is due to the presence of hydrocarbons and sulfur and the radioactivity is the result of the leaching of thorium and uranium daughters present in the oil-producing formation and their transport by the extracted fluids to the production rigs. Because of the presence of these radioactive materials of natural origin, this waste is named TENORM (Technologically Enhanced Naturally Occurring Radioactive Material). The main radionuclides present are 210Pb, 224Ra, 226Ra and 228Ra. In Brazil, the offshore platforms cannot dispose this waste by reinjection in wells because federal law prohibits disposal of radioactive waste in seawaters or seabed. The waste is, therefore transported to land and stored. This work aims at investigating a method of decontaminating the oil sludge by using surfactant that can increase the removal efficiency of the radionuclides. After a successful treatment, the decontaminated waste can be disposed of as non-radioactive industrial waste in a licensed facility and the concentrated radioactive material can be treated as radioactive waste, decreasing significantly the costs of management and improving safety.

    Palavras-Chave: daughter products; decontamination; lead 210; naturally occurring radioactive materials; offshore platforms; petroleum industry; radioactive waste management; radioactive wastes; radium 224; radium 226; radium 228; sludges; surfactants

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  • IPEN-DOC 26858

    BERGAMASCHI, VITOR; CARNEIRO, MARCELO B.; ROSSI, WAGNER de ; NEVES, MAURICIO D.M. . Tratamento térmico de endurecimento por laser pulsado de Nd:YAG em aço-rápido / Hardening heat treatment by Nd:YAG pulsed laser in high-speed steel. In: CONGRESSO BRASILEIRO DE ENGENHARIA DE FABRICAÇÃO, 10., 5-7 de agosto, 2019, São Carlos, SP. Anais... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2019.

    Abstract: O uso do laser no processamento de materiais é uma área de pesquisa em ascensão, sendo que o mesmo tem sido utilizado em processos avançados de fabricação e em tratamentos superficiais. Quanto aos tratamentos superficiais, destaca-se o de endurecimento seletivo, que provoca o aumento de dureza da superfície do material da peça, possibilitando a redução do desgaste e aumento no tempo de vida do componente. Nesse sentido, o objetivo do trabalho foi avaliar a influência de alguns parâmetros de aplicação do laser pulsado de Nd:YAG na alteração sub-superficial de uma amostra de aço-rápido sinterizado (HSS/PM). Para tanto, foi realizada a preparação metalográfica da seção transversal da amostra atacada pelo laser, para em seguida realizar as caracterizações por microscopia óptica e eletrônica de varredura, mecânica através do ensaio de microdureza Vickers e física para a identificação das fases formadas através da difração de raios-X (DRX). A análise dos resultados mostrou que os parâmetros do laser influenciaram significativamente na profundidade da alteração sub-superficial, da mesma forma que promoveram variação de dureza, provavelmente, devido a formação de martensita e carbonetos detectadas em DRX.

    Palavras-Chave: lasers; hardness; steels; microhardness

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  • IPEN-DOC 26053

    PRADO, E.S.P. ; MIRANDA, F.S.; PETRACONI, G.; POTIENS JUNIOR, A.J. . Tratamento de rejeitos radioativos compactáveis aplicando a tecnologia plasma para redução volumétrica. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26433

    SOUZA, ANDERSON L. de . Tratamento de efluentes provenientes da indústria curtidora, empregando acelerador de elétrons / Treatment of effluents from tannery, using electron accelerator . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 98 p. Orientador: Sueli Ivone Borrely. Coorientador: Maria Aparecida Faustino Pires. DOI: 10.11606/D.85.2019.tde-21112019-155745

    Abstract: A indústria curtidora brasileira está entre os principais países produtores de couro do mundo. O processo produtivo de um curtume tem por finalidade transformar a pele animal em couro e envolve uma sequência de reações químicas complexas e o consumo significativo de água. O efluente do processo de curtimento se caracteriza pela alta salinidade, alto teor de matéria orgânica, presença de corantes, surfactantes, sulfeto e cromo. Os curtumes normalmente possuem estações de tratamento de efluentes, visando minimizar seus impactos ambientais e atender à legislação vigente para padrões de lançamento. Dentre as tecnologias alternativas de tratamento de efluentes, têm-se os Processos de Oxidação Avançada (POA's). O objetivo deste trabalho foi avaliar a eficiência da radiação ionizante para o tratamento de efluentes da indústria curtidora, empregando acelerador de elétrons. Os efluentes brutos de um curtume foram irradiados com doses de 10, 20, 30, 40, 50 e 60 kGy. A eficiência deste processo e do tratamento convencional (coagulação/floculação) foram avaliadas pelos resultados dos parâmetros de cromo hexavalente, demandas química e bioquímica de oxigênio (DQO e DBO), óleos e graxas, sólidos suspensos totais e sulfeto, além do ensaio de toxicidade aguda com o microcrustáceo Daphnia similis. A radiação ionizante mostrou-se eficiente, alcançando remoção média para DBO (29,4%), DQO (20,2%), óleos e graxas (26,7%), sólidos suspensos totais (36,6%) e sulfeto (74,3%). Quanto ao parâmetro ecotoxicidade, as amostras originalmente apresentaram-se com elevada toxicidade para efeito agudo em dafnídeos e a irradiação resultou em remoção média de 34,0% da toxicidade nos efluentes irradiados.

    Palavras-Chave: liquid wastes; waste water; waste processing; leather; industrial wastes; toxicity; acute irradiation; daphnia; microorganisms; linear accelerators; electron beams; ionizing radiations

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  • IPEN-DOC 26187

    SILVA, RITA de C.A. da ; SAIKI, MITIKO ; MOREIRA, EDSON G. ; OLIVEIRA, PAULO T.M.S.; THEOPHILO, CAROLINA Y.S. ; SANCHES, THAIS C.; COIMBRA, AMANDA A.; BIANCHI, TICIANA Z.D.. Trace elements in livers of great egrets (Ardea Alba) from São Paulo metropolitan region: temporal considerations (2006-2013) and the relations with sex and mass of birds. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 881-890.

    Abstract: To evaluate possible variations over time (2006-2013) in trace element levels in livers from adult specimens of great egret from the São Paulo Metropolitan Region (SPMR), recent data and published data have been used. The elements Br, Cl, Co, Cs, Cu, Fe, K, Mg, Mn, Na, Rb, Se and Zn were determined by Neutron Activation Analysis (NAA) and the toxic elements Cd and Hg by Atomic Absorption Spectrometry (AAS). The large inter annual variations observed for several elements showed the importance of expanding the time period for this analysis as the series is considered short (<10 years). However, non-significant increase of Br, Cu, Mn, Fe and Zn and a decrease in Cd, also non- significant, were observed at the end of the series. The concentration relations with sex and mass of the birds were also assessed. Females presented lower concentrations of Br, Co, Cs, Se and Zn and it may be related to metabolic differences, detoxification pathways, and other factors. No relationship between body mass and element levels were observed. Obtained results demonstrated the importance of temporal monitoring of trace elements in livers of great egrets, especially for the results obtained for Cu, Fe and Zn, since the contamination by these elements in the region should be considered. The present study is the first relating contaminant level with conditions of birds in the region, encouraging future studies that evaluate this issue.

    Palavras-Chave: absorption spectroscopy; aquatic organisms; birds; contamination; ecological concentration; elements; liver; neutron activation analysis; trace amounts

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  • IPEN-DOC 26155

    JUNQUEIRA, LUCAS S. ; SILVA, SHARLLENY A.; FRANKLIN, ROBSON L.; FAVARO, DEBORAH I.T. . Trace element assessment in sediment cores from Graminha reservoir, São Paulo State, by INAA. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 505-520.

    Abstract: In the present study, sediment cores were collected in the Graminha (Caconde) water supply reservoir in Feb/2015 (points 1 and 3) and Aug/2015 (points 1 and 4) sampling campaigns. The four sediment cores with different depths were cut every 2.5 cm, yielding 36, 21, 33 and 37 slices of sediments, respectively, that were individually analyzed by INAA (Instrumental Neutron Activation Analysis). This analytical technique was used to quantify the elements: As, Ba, Br, Co, Cr, Cs, Fe, Hf, Rb, Sb, Sc, Ta, Zn, U and Th. The validation of precision of the methodolody was made by analyzing certified reference material. The concentration values obtained for As, Cr and Zn were compared with TEL and PEL oriented values established by the CCME (Canada) and adopted by CETESB for sediment quality evaluation. None of the sediment cores analyzed surpassed the PEL value for these elements. Sediment samples from points 2 and 3 presented the worst sediment quality but were still classified as good quality for sediments. The enrichment factor (EF) and Geoacumulation Index (IGeo) tools used for contamination level assessment were used for all sediment cores and mostly presented enrichment on As and U. The results from concentrations, EF and IGeo showed a significant increase mostly below 30 cm of depth in every core. Statistical analyses were applied to the elemental concentration values for better interpretation of the results.

    Palavras-Chave: elements; evaluation; metals; neutron activation analysis; sampling; sediments; trace amounts; water reservoirs; brazil

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  • IPEN-DOC 26240

    SOUSA, GRAZIELLY M. de ; GEMELLI, KARINE K. ; MARTINS, OZENILDE A.R.; OLIVEIRA, MARIA J.A. de ; ALCANTARA, MARA T.S. ; LUGAO, ADEMAR B. ; ROGERO, JOSE R. . Toxicity study using rat (WISTAR) model of a hydrogel dressing with silver nanoparticles crosslinked and sterilized by gamma radiation. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1871-1878.

    Abstract: Silver nanoparticles (NPAg) have a bactericidal and bacteriostatic action in combination with hydrogels to recover the damaged tissue, promoting healing of the wound. The objective of this study was to evaluate the toxicity of the hydrogel dressing with NPAg from the analysis of possible toxic effects on renal and hepatic functions. It is an experimental study with 85 male Wistar rats, young adults. Nanoprate hydrogel and bidrogel dressings were used at concentrations of 22 and 44 ppm, both crosslinked and sterilized by irradiation with gamma rays at the 25 kGy dose at the center of radiation technology (CTR). The animals were distributed according to the treatment received after surgical induction of the wound on the animal's back. They were euthanized with 24 hours, 3, 7, 14, 21 and 30 days and after collecting the blood to determine the biochemical parameters. The project was approved by CEUA FAPAC ITPAC PORTO. Data were analyzed using the Past, Shapiro-Wilk and Kruskal-Wallis programs. For distribution and comparison data ANOVA and Tukey test with a significance level of 95%. No changes were observed in relation to biochemical parameters (TGP, TGO, urea and creatinine), and there were no statistically significant differences between the three groups of animals, independent of time. It was possible to observe that the animals treated with 44 ppm had always lower mean values than the other two groups in all analyzes. The study showed that the dressings of NPAg tested may not induce toxicity, being necessary to complement with other tests, such as histopathological study and atomic absorption spectroscopy.

    Palavras-Chave: absorption spectroscopy; gamma radiation; healing; hydrogels; mice; nanoparticles; silver; sterilization; toxicity; wounds

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  • IPEN-DOC 26175

    GARCIA, VANESSA S.G. ; BOIANI, NATHALIA F. ; ROSA, JORGE M ; BORRELY, SUELI I. . Toxicity of textile effluents treated by electron beam technology. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 735-742.

    Abstract: The textile industry uses expressive amount of water during the production and generate effluents that contain residuals of dyes, surfactants, peroxides, acids and salts, and toxicity. In addition, the textile effluents are commonly colored, because the dyes used in fibers dyeing usually have low fixation and high solubility. Many of the mentioned products are not easily removed, requiring additional treatment steps. Advanced Oxidative Processes, such as electron beam irradiantion (EBI), can be a good alternative to reduction of organic pollutants from effluents. Therefore, studies on these contaminants in aquatic environment are important for assessing their impacts on ecosystems and water quality. The objective of this study was to evaluate the toxicity of textile effluents treated with EBI. The doses of 2.5 kGy and 5.0 kGy were used. The toxicity assays were performed with Daphnia similis organisms, exposed to samples during 48 hours, and the results expressed by EC50 (median effective concentration). For the textile effluent, EC 50% values ranged from: 2.95 ±0.13 (raw effluent) until 20.90 ±1.48 (irradiated effluent, at 5kGy). The EBI treatment was effective for toxicity reduction, with efficiency higher than 60% (2.5 kGy) and 80% (5.0 kGy). The study of organic and inorganic contaminants, presents in these effluents, demonstred EC 50 values below 5%. These results demonstrate high toxicity of contaminants from textile effluents for aquatic organisms (D. similis, cladocera). Similar data was observed for the raw effluent. These values are relevant for thinking radiation as a possible technology for such a type of effluent.

    Palavras-Chave: chemical effluents; decontamination; electron beams; environment; industrial wastes; irradiation; liquid wastes; pollutants; textile industry; textiles; toxicity; water quality

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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.

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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.

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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.